COMPOSITIONS CONTAINING 1,1-DISUBSTITUTED ACTIVATED ALKENES USEFUL IN ADDITIVE MANUFACTURING AND ARTICLES FORMED THEREFROM

CROSS-REFERENCE TO RELATED APPLICATION(S)

[001] This application claims priority to and the benefit of U.S. Provisional Application Patent Serial No. 62/965,271 , filed January 24, 2020, the entire disclosure of which is hereby incorporated by reference.

FIELD

[002] This disclosure relates to compositions containing 1 , 1 -disubstituted activated alkenes, methods for using the compositions for additive manufacturing and articles prepared from the methods.

BACKGROUND

[003] 1 ,1 -disubsituted alkene compounds, such as methylene malonates, contain two ester and/or ketone groups, and an alkylene group disposed between the two groups. Recent developments in synthesis of these compounds facilitate the synthesis of these compounds and their use in a variety of applications, see Malofsky US 8,609,885; US 8,884,051 ; and US 9,108,914; incorporated herein by reference in their entireties for all purposes. Malofsky et al. WO 2013/059473, US 2014/0329980, US 9,512,058, incorporated herein by reference in their entirety for all purposes, discloses the preparation of multifunctional methylene malonates by multiple synthetic schemes. One disclosed process involves reacting a methylene malonate with a polyol in the presence of a catalyst to prepare compounds wherein one of the ester groups on the methylene malonates undergoes transesterification to react with the polyol and form multifunctional compounds (multifunctional meaning the presence of more than one methylene malonate core unit). WO 2019/014528 discloses polymerization of 1 ,1 -disubsituted alkene compounds using free radical polymerization initiated using free radical photoinitiators and UV light. WO 2018/219729 discloses additive manufacturing processes utilizing mixtures of 1 ,1 - disubsituted alkene compounds and acrylates which are cured by radiation in the presence of a photoinitiator. Exemplified is free radical curing of the mixtures using a free radical initiator.

[004] Additive manufacturing is the process of joining materials to make structures from a 3- dimensional model one layer at a time, this process is more commonly referred to a 3D printing. In additive manufacturing a part is built up layer by layer using powders or liquids. The process starts by drawing a three-dimensional computer-aided design model using software, often referred to as CAD software. The software used allows the design to be partitioned into layers. Each layer is sent to a device, such as a printer, to be applied with each subsequent layer being deposited on the previous layer to form the structure. Standard additive manufacturing processes include material extrusion, vat photo polymerization, powder bed fusion, binder jetting, sheet lamination, material jetting and directed energy deposition. Commercially available UV cured systems are largely based on free radical chemistry of urethane and epoxy (meth)acrylates. However, a limitation of these types of technologies is the susceptibility to oxygen inhibition effect of free radicals that leads to tacky exposed surfaces. These systems require exposure to radiation for polymerization for cure to proceed. Once the exposure to radiation is discontinued further cure of the materials or structures formed ceases. As a result, the articles formed may crack or warp or have surface roughness. To address these issues a number of post curing processes have been developed which may address the surface issues or which may require chemical treatment which results in additional cost for disposal of the chemicals or further damage to the parts by the chemicals or the post cure step.

[005] Curable compositions that contain 1 , 1 -disubstituted activated alkenes are useful for printing 3D articles. Current methods for curing compositions that contain 1 ,1 -disubstituted activated alkenes include liquid binding, exposure to ultraviolet radiation (UV) or thermal cure. These methods require many steps including manipulating curable parts between cures, changing wavelengths between cure steps and moving the curable parts to secondary ovens/apparatuses. Curing compositions into unsymmetrical or asymmetrical shapes can be difficult using liquid binders with ultraviolet radiation or thermal cure because those methods often cure compositions unevenly and leave undesirable dark spots. The techniques can leave residues of by-products on the surfaces of the cured objects that need to be removed with various solvents and wipes. A number of references disclose compositions of polymer blends that are post-curable, such as those compositions disclosed in US publication 2019/0160739 and WO2018/219729. The commercially available processes for additive manufacturing build up the structures layer by layer and adhesion between layers is limited due to the limited exposure of each layer to radiation. [006] There is a need for curable compositions containing 1 ,1 -disubstituted activated alkenes that have controlled polymerization rates, complete polymerization conversion and increased gelation stability. There is a need for curable compositions containing 1 ,1 -disubstituted activated alkenes which enhance bonding adhesion between layers and which require minimal or no post curing of the structures. There is a need for curable compositions containing 1 ,1- disubstited activated alkenes that have increased shelf life and provide cost-effective additive manufacturing. There is a need for a curable composition containing 1 ,1 -disubstituted activated alkenes with reduced yellowing that stems from common curing methods. SUMMARY

[007] Disclosed are curable compositions comprising a mixture of a) one or more first compounds comprising one or more 1 ,1-disubstituted activated alkene compounds; b) one or more photolatent bases which when exposed to radiation forms an amine which initiates anionic polymerization of the one or more 1 ,1-disubstituted activated alkene compounds; and c) one or more acidic compounds which slow anionic polymerization of the one or more 1 ,1-disubstituted activated alkene compounds wherein the one or more acidic compounds are present in an amount sufficient to slow the anionic cure rate. The one or more photolatent bases form one or more amines that initiate anionic polymerization upon exposure to radiation, a radiation source. The one or more photolatent bases may form amines comprising one or more amino, amidine or guanidine groups or a carbanion. The one or more 1 ,1 -disubstituted activated alkene compounds comprise one or more 1 ,1 -dicarbonyl substituted-1-alkenes or cyano-acrylates. The photolatent base may also form or generate free radicals upon exposure to radiation. These free radicals can initiate free radical polymerization. When the photolatent base upon exposure to radiation forms free radicals and an amine which functions as an anionic polymerization initiator, free radical polymerization and anionic polymerization may be initiated. The composition may contain one or more other free radical photoinitiators which upon exposure to radiation forms free radicals that initiate free radical polymerization. Exemplary classes of photoinitiators include one or more of alpha aminoketones, alpha hydroxyketones, phosphine oxides, phenylglyoxalates, thioxanthones, benzophenones, benzoin ethers, oxime esters, acetophenones, dyes that can be excited by UV and visible parts of the electromagnetic spectrum, such as fluorone dyes, cyanine and phthalocyanine dyes and coumarins, peroxides and azo compounds, or mixtures thereof. The composition may comprise one or more second compounds which are free radically polymerizable when exposed to free radicals generated by exposure of a photoinitiator to radiation, for example one or more (meth)acrylates, conjugated dienes, vinylidene substituted aromatic monomers, vinylidene halides, vinyl acetates, unsaturated nitriles cyanoacrylates, maleates, fumarates, maleimides and itaconates. The composition may comprise one or more third compounds which are anionically polymerizable, for example epoxy functional or isocyanate functional compounds. The compositions may comprise one or more fourth compounds which are compounds, oligomers or polymers having functional groups which Michael add to unsaturated groups when exposed to amines. Such compounds, oligomers or polymers may contain thiol or hydroxyl groups that can Michael add to unsaturated groups. The compositions disclosed may contain mixtures of 1 ,1 -disubstituted activated alkene compounds with one or more of the second, third and fourth compounds. The compositions may comprise one or more photosensitizers. The photosensitizers broaden the wavelengths of radiation at which the photolatent bases form amines, and optionally free radicals and/or at which the free radical photoinitiator forms free radicals that initiate free radical polymerization. The acidic compound may be one or more of carboxylic acids, sulfonic acids, sulfuric acids and phosphoric acids or esters thereof. The composition may further comprise one or more free radical polymerization initiators, which are not photoinitiators, which may be one or more peroxide or azo compounds. The composition may contain one or more fillers. The one or more fillers may be in the form of one or more of particles, fibers, pigments, or hollow spheres.

[008] Disclosed is a composition wherein the one or more 1 , 1 -disubstituted activated alkene compounds are present in an amount of about 10 percent by weight to about 99 percent by weight based on the weight of the curable composition. The composition may comprise the one or more one or more second compounds which are free radically polymerizable present in an amount of about 1 percent by weight to about 90 percent by weight based on the weight of the curable composition. The composition may comprise the one or more third compounds that are anionically polymerizable present in an amount of about 1 percent by weight to about 90 percent by weight based on the weight of the curable composition. The composition may comprise one or more fourth compounds present in an amount of about 1 percent by weight to about 90 percent by weight based on the weight of the curable composition. The one or more fourth compounds may be simple compounds, oligomers or polymers containing groups which Michael add to unsaturated groups. The composition may contain the one or more photolatent bases present in an amount of about 0.05 to about 15 percent based on the weight of the composition. The one or more acidic compounds may be present in an amount of about 10 ppm (0.0001 weight percent) to 10,000 ppm (1 .0 weight percent) based on the weight of the composition. The one or more free radical photoinitiators may be present in an amount of about 0.05 to about 20 percent by weight based on the weight of the curable composition. The one of more fillers may be present in an amount of about 1 to about 50 percent by weight based on the weight of the curable composition. [009] A two part composition comprising in one part: a) one or more first compounds comprising one or more 1 ,1 -disubstituted activated alkene compounds; b) one or more acidic compounds; and in a second part c) one or more weak bases and/or photolatent bases which when exposed to ultraviolet radiation releases one or more amines that initiate anionic polymerization, d) a compound that initiates anionic polymerization of the one or more compounds 1 ,1 -disubstituted activated alkene compounds or a free radical initiator that initiates free radical polymerization of the one or more 1 ,1 -disubstituted activated alkene compounds; such that when the components are mixed and exposed to radiation the one or more 1 ,1 -disubstituted activated alkene compounds undergo both free radical polymerization and anionic polymerization, wherein the one or more acidic compounds is present in an amount sufficient to slow the anionic cure rate. The two parts of the composition may be combined and used in additive manufacturing processes. The two-part compositions may contain the components disclosed in this application in the disclosed amounts. The components that are reactive with one another are kept in different parts until reaction is desired.

[0010] Disclosed are cured articles comprising a plurality of layers wherein each layer comprises a mixture of polymers prepared from a composition as disclosed herein with layers that may be connected by cohesive forces created by anionic polymerization, Michael Addition and/or crosslinks between one or more first compounds comprising one or more 1 ,1 -disubstituted activated alkene compounds or multifunctional 1 ,1 -disubstituted activated alkene compounds. The cured article may have improved tensile strength of the article in direction transverse to the layers and\or shear strength between the layers. The improved tensile and shear strengths may be a result of cohesive bonds or crosslinking between the polymer chains of the layers.

[0011] Disclosed is a method comprising: i) forming a layer of a one part composition disclosed herein; ii) exposing the layer to radiation so as to cause the photolatent base to generate an amine which initiates anionic polymerization under conditions such that the anionic polymerization proceeds and is slower than where no acid is present or than free radical polymerization; iii) applying in sequence upon each layer another layer of the mixture while the anionic cure of the layer upon which each layer is deposited is still proceeding; iv) exposing each succeeding layer to radiation; wherein succeeding layers are applied until a desired shape is formed. The method wherein the photolatent base initiates free radical polymerization, or where the composition contains separate free radical photoinitiator that initiates free radical polymerization results in the initiation of free radical polymerization and anionic polymerization. Under these conditions the acidic compound is present in an amount sufficient to result in anionic polymerization slower than free radical polymerization and continues after exposure to radiation is discontinued. It is desirable for the anionic polymerization to continue until and after the next layer is applied.

[0012] Disclosed are methods comprising mixing the two parts of a two part composition as disclosed in this application, forming a discrete layer from the mixture; exposing the discrete layer of the mixture to radiation such that the photolatent base releases an amine that initiates anionic polymerization; applying in sequence upon each layer another layer of the mixture of the two parts while the anionic polymerization of the layer upon which each layer is deposited is still proceeding; and exposing each succeeding layer to radiation; wherein succeeding layers are applied until a desired shape is formed.

DETAILED DESCRIPTION

[0013] The explanations and illustrations presented herein are intended to acquaint others skilled in the art with the teachings, its principles, and its practical application. The specific embodiments of the present teachings as set forth are not intended to be exhaustive or limiting of the teachings. The scope of the teachings should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. Other combinations are also possible as will be gleaned from the following claims, which are also hereby incorporated by reference into this written description. Unless defined otherwise, all technical and scientific terms used herein have the meaning commonly understood by a person skilled in the art.

[0014] Disclosed are compositions including one or more first compounds of 1 ,1 -disubstituted activated alkenes, one or more photolatent bases which when exposed to radiation generates an amine which initiates anionic polymerization of the one or more 1 ,1 -disubstituted activated alkene compounds; and one or more acidic compounds which inhibit anionic polymerization of the one or more 1 ,1 -disubstituted activated alkene compounds present in amounts sufficient such that the that the anionic cure rate is controlled. The photolatent base may initiate free radical polymerization upon exposure to radiation. Alternatively, the composition may contain a separate free radical photoinitiator that initiates free radical polymerization upon exposure to radiation. Alternatively, a Norrish Type I or Type II free radical initiator may be used in the compositions either in the one part or two-part compositions. Where a free radical initiator or free radical photoinitiator is present the amount of acid present is present in an amount sufficient to adjust the rate of anionic polymerization such that the rate of anionic polymerization is slower than free radical polymerization and the anionic polymerization continues after exposure to radiation is discontinued. The composition may contain one or more second compounds that undergo free radical polymerization, one or more third compound which undergo anionic polymerization and/or fourth compounds that react with unsaturated groups on the 1 ,1 -disubstituted activated alkenes or the residues of such in the formed polymer chains by Michael Addition.

[0015] The one or more first compounds of 1 ,1 -disubstited activated alkenes may comprise any compound which contains an unsaturated carbon bond adjacent to one or more electron withdrawing groups. The unsaturated group adjacent to an electron withdrawing group is easily reacted with a nucleophile. The nucleophilic attack on such unsaturated group starts or propagates anionic polymerization.

[0016] 1 ,1 -disubstited activated alkenes may be referred to by a number of different names, such as 1 ,1-di-activated vinyl compounds and the electron deficient olefins. 1 ,1-di-activated vinyl compounds have been defined as a compound comprising a vinyl group having two electron withdrawing groups (EWG) covalently bonded to one of the tt-bonded carbons and no substituents covalently bonded to the other tt-bonded carbon (i.e., -EWG-C(=CH2)-EWG-), wherein the electron withdrawing groups independently comprise halogen groups, haloalkyl groups, carbonyl-containing groups (e.g., esters, amides, aldehydes, ketones, acyl halides, carboxylic/carboxylate groups), cyano groups, sulfonate groups, ammonium groups, quaternary amine groups, or nitro groups. Electron deficient olefins have two or more electron withdrawing groups attached thereto, which may be the same or different. The electron deficient olefin may be a compound having one end terminating with a cyanoacrylate, cyanopentadienoate, cyanohexadienoate, or alkylene derived from dimalonate and another end terminating with a group selected from branched and unbranched alkyl esters, esters containing aromatics and heterocyclic nuclei, (meth)acrylates, cyanoacrylates, siloxanes, blocked and unblocked isocyanates, anhydrides, silanes, vinyls, acetylenes, and epoxies. Exemplary electron deficient olefins include compounds which have two electron withdrawing groups attached thereto which are different, such as 2-cyanoacrylate esters. Exemplary 2-cyanoacrylates include those having ester groups of methyl, ethyl, propyl, isoamyl, propargyl, butyl, pentyl, hexyl, octyl, nonyl, oxononyl, decyl, dodecyl, allyl, ethynyl, butenyl, cyclohexyl, phenyl, phenethyl, tetrahydrofurfuryl, chloroethyl, 2,2,2-trifluoroethyl, hexafluoroisopropyl, methoxymethyl, thiomethoxymethyl, methoxyethyl, thiomethoxyethyl, methoxybutyl, thiomethoxybutyl, ethoxyethyl, thioethoxyethyl, propoxyethyl, thioproxyethyl, butoxymethyl, thiobutoxymethyl, butoxyethyl, thiobutoxyethyl and dimethyl siloxane esters of 2-cyanoacrylic acid. Exemplary 1 ,1 -disubstited activated alkenes include 1 ,1 -dicarbonyl-1 -alkenes, disubstituted vinyls, dihaloalkyl disubstituted vinyls, cyanoacrylates, and cyanopentadienoates. Any of the described compounds may be used in the compositions described herein.

[0017] 1 ,1 -disubstited activated alkenes compounds include compounds corresponding to formula 1 of US Patent Publication 20100210788 relevant portions incorporated herein by reference. The activated alkene may be any of a wide range of activated alkenes possessing an electron-deficient substituent on one, or both of the activated alkeneic carbons. Electron withdrawing group(s), include any substituent that draws electrons away from the alkene. Exemplary electron withdrawing groups include hydroxy, alkoxy, mercapto, halogens, carbonyls, sulfonyls, nitrile, quaternary amines, nitro, trihalomethyl, imine, amidine, oxime, thioketone, thioester, or thioamide groups. The electron withdrawing group(s) maybe hydroxy, alkoxy, mercapto, halogen, carbonyl, sulfonyl, nitrile, quaternary amine, nitro, or trihalomethyl groups. The electron withdrawing group(s) may be halogen, carbonyl, nitrile, quaternary amine, nitro, or trihalomethyl. The electron withdrawing group(s) may be carbonyl or nitrile. The electron withdrawing group(s) may be carbonyl.

[0018] 1 ,1 -disubstited activated alkenes may be 1 ,1 -dicarbonyl substituted alkenes, commonly known as methylene malonates, methylene beta-ketoesters or methylene beta- diketones. Compounds containing 1 ,1 -dicarbonyl 1 -alkenes are compounds that contain two carbonyl groups and a double bond bonded to a single carbon atom referred to as the one carbon atom. The carbonyl groups may be separately in each occurrence bonded to hydrocarbyl groups through a direct bond, oxygen or amino groups. As used herein, diester refers to any compound having two ester groups bonded to the 1 carbon atom. A 1 ,1 -diester- 1-alkene is a compound that contains two ester groups and a double bond bonded to the one carbon atom. Dihydrocarbyl dicarboxylates are diesters having a hydrocarbylene group between the ester groups wherein a double bond is not bonded to a carbon atom which is bonded to two carbonyl groups of the diester. [0019] The term “monofunctional” in reference to the 1 ,1 -dicarbonyl 1 -alkenes, such as 1 ,1- diester-1 -alkenes, refer to compounds having only one core unit. The core unit comprises two carbonyl groups and a double bond bonded to a single carbon atom. The term “difunctional” refers to the 1 ,1 -dicarbonyl 1 -alkenes such as 1 ,1 -diester- 1 -alkenes having two core units (each including the reactive alkene functionality) bound through a hydrocarbylene linkage between one oxygen atom on each of two core formulas. The term “multifunctional” refers to the 1 ,1 -dicarbonyl 1 -alkenes such as 1 ,1 -diester-1 -alkenes having two or more core units (each core unit including the reactive alkene functionality) bound together through a hydrocarbylene linkage between one oxygen atom on each of two or more core formulas.

[0020] The doubly bonded carbons may be part of an alkenyl group that is highly reactive. The alkenyl group may be a C2-4 alkenyl group, or a methylene group (C=C). Only one of the carbon groups of the alkenyl group are bound to the carbonyl groups. The di-carbonyl compounds contain hydrocarbyl groups bonded to directly to the carbonyl groups or to an oxygen or nitrogen bonded to the carbonyl groups wherein the hydrocarbyl groups may contain one or more heteroatoms, including heteroatom containing functional groups. The heteroatom functional groups may contain unsaturated groups that are capable of free radical or anionic polymerization. The hydrocarbyl groups bound directly to or indirectly to the carbonyl groups may be separately in each occurrence alkyl, alkenyl, cycloalkyl, heterocyclyl, alkylsubstituted heterocyclyl, aryl, aralkyl, alkaryl, heteroaryl, alkyl substituted heteroaryl, or polyoxyalkylene, or both of the hydrocarbyl groups may form a 5-7 membered cyclic or heterocyclic ring. The hydrocarbyl groups may be separately in each occurrence C1 -C15 alkyl, C2-C15 alkenyl, C3-C9 cycloalkyl, C2-20 heterocyclyl, C3-20 alkyl substituted heterocyclyl, Ce-18 aryl, C7-25 alkaryl, C 7-25 aralkyl, C5-18 heteroaryl or Ce-25 alkyl substituted heteroaryl, or polyoxyalkylene, or both hydrocarbyl groups form a 5-7 membered cyclic or heterocyclic ring. The recited groups may be substituted with one or more substituents, which do not interfere with the use of these compounds as described herein. Exemplary substituents include halo, alkylthio, alkoxy, hydroxyl, nitro, azido, cyano, acyloxy, carboxy, ester or unsaturated groups. The hydrocarbyl groups connected to the carbonyl group may be separately in each occurrence C1 -C15 alkyl, C3-C6 cycloalkyl, C4-18 heterocyclyl, C4-18 alkyl substituted heterocyclyl, C6-18 aryl, C7-25 alkaryl, C7-25 aralkyl, C5-18 heteroaryl or Ce-25 alkyl substituted heteroaryl, or polyoxyalkylene. The hydrocarbyl groups connected to the carbonyl group may be separately in each occurrence a C1-6 alkyl or cyclohexyl. The hydrocarbyl groups connected to the carbonyl group may be separately in each occurrence methyl, ethyl, propyl, butyl, pentyl, hexyl or cyclohexyl. The hydrocarbyl groups connected to the carbonyl group may be the same for each hydrocarbyl group on the 1 ,1-dicarbonylsubstituted-1 -alkene compounds. Exemplary compounds are dimethyl, diethyl, ethylmethyl, dipropyl, dibutyl, dihexyl, dicyclohexyl, diphenyl, and/or ethyl-ethylgluconate malonates. The compounds may be dimethyl, diethyl dihexyl, and/or dicyclohexyl methylene malonates. The 1 ,1 -dicarbonyl substituted- 1-alkenes can be prepared as disclosed in Malofsky et al., US 8,609,885; 8,884,051 ; 9,221 ,739 and 9,527,795; and Malofsky et al. US 9,108,914.

[0021] The 1 ,1- dicarbonyl substituted -1-alkene compounds may correspond to formula 1 :

R ¹ is separately in each occurrence a group that can undergo replacement or transesterification under the conditions of the methods disclosed herein. R ¹ may be separately in each occurrence alkyl, alkenyl, cycloalkyl, heterocyclyl, alkyl substituted heterocyclyl, aryl, aralkyl, alkaryl, heteroaryl, or alkyl substituted heteroaryl, or polyoxyalkylene, or both R ¹ s form a 5-7 membered cyclic or heterocyclic ring. R ¹ may be separately in each occurrence C1 -C15 alkyl, C2-C15 alkenyl, C3-C9 cycloalkyl, C2-20 heterocyclyl, C3-20 alkyl substituted heterocyclyl, C6-18 aryl, C7-25 alkaryl, C 7-25 aralkyl, C5-18 heteroaryl or Ce-25 alkyl substituted heteroaryl, or polyoxyalkylene, or both Ri groups form a 5-7 membered cyclic or heterocyclic ring. The recited groups may be substituted with one or more substituents, which do not interfere with the uses of these compounds as disclosed herein. Exemplary substituents include halo alkylthio, alkoxy, hydroxyl, nitro, azido, cyano, acyloxy, carboxy, ester or unsaturated groups. R ¹ may be separately in each occurrence C1 -C15 alkyl, C3-C6 cycloalkyl, C4-18 heterocyclyl, C4-18 alkyl substituted heterocyclyl, C6-18 aryl, C _7- 25 alkaryl, C7-25 aralkyl, C5-18 heteroaryl or Ce-25 alkyl substituted heteroaryl, or polyoxyalkylene. R ¹ may be separately in each occurrence a C1-6 alkyl or C _5-6 cycloalkyl. R ¹ may be separately in each occurrence methyl, ethyl, hexyl, or cyclohexyl. R ¹ may be the same or different for each hydrocarbyl group on the 1 , 1 -disubstituted alkene compounds.

[0022] The 1 ,1 -disubstituted alkene compounds may be methylene malonates which may correspond to formula 2: wherein R ¹ is as described herein before.

The 1 ,1 dicarbonyl 1-alkene may correspond to one of the following formulas:

[0023] which may be optionally substituted. It should be noted that the vinyl residue on the right is not limited to acrylates but may be a vinyl ether, vinyl ester, styryl, dienyl, acrylamide, etc. The one or more 1 ,1 -disubstited activated alkenes may comprise one or more multifunctional 1 ,1- dicarbonylsubstituted-1-alkenes. The one or more multifunctional 1 ,1-dicarbonylsubstituted-1- alkenes include compounds which contain two or more 1 ,1 -dicarbonyl 1-alkene groups and may be difunctional compounds containing 1 ,1 -dicarbonyl 1- alkene groups or multifunctional compounds containing 1 ,1 -dicarbonyl 1 - alkene groups. Such compounds may comprise two or more 1 ,1 -dicarbonyl 1- alkene groups connected by the residue of a diol or polyol capable of transesterifying 1 ,1 -dicarbonyl 1- alkenes. The multifunctional compounds may comprise a number of 1 ,1 -dicarbonyl 1 - alkenes linked by diols. The diol may correspond to the formula: HO — R ² — OH wherein R ² is separately in each occurrence a hydrocarbylene group having two or more bonds to the hydroxyl groups of a polyol. R ² may be separately in each occurrence alkylene, alkenylene, cycloalkylene, heterocyclylene, alkyl substituted heterocyclylene, arylene, aralkylene, alkarylene, heteroarylene, alkyl substituted heteroarylene, or polyoxyalkylene. R ² may be separately in each occurrence C1-C15 alkylene, C2-C15 alkenylene, C3-C9 cycloalkylene, C 2-20 heterocyclylene, C 3-20 alkyl substituted heterocyclylene, Ob-ib arylene, C7-25 alkarylene, C7-25 aralkylene, C5-18 heteroarylene, Ce-25 alkyl substituted heteroarylene or polyoxyalkylene. The recited groups may be substituted with one or more substituents that do not interfere with the transesterification or polymerization. Exemplary substituents include halo, alkylthio, alkoxy, hydroxyl, nitro, azido, cyano, acyloxy, carboxy, or ester. R ² may be separately in each occurrence a C 2-8 alkylene group, such as ethylene, propylene, butylene, pentylene, hexylene, 2-ethyl hexylene, heptylene, 2- methyl 1 ,3 propylene or octylene. Exemplary C3-C9 cycloalkylenes include cyclohexylene. The alkylene groups may be branched or straight and may have a methyl group on the 2 carbon. Among preferred alkyl arylene polyols are polyols with the structure of -aryl-alkyl-aryl- (such as -phenyl-methyl-phenyl- or -phenyl-propyl-phenyl-) and the like. Among preferred alkyl cycloalkylene poly-yls are those with the structure of -cycloalkyl-alkyl-cycloalkyl- (such as - cyclohexyl-methyl-cyclohexyl- or -cyclohexyl-propyl-cyclohexyl-) and the like. The polyalkylene oxy groups may have alkylene groups of ethylene, propylene or butylene and the butylene groups may be derived from butylene oxides or tetrahydrofuran. c may be an integer of 8 or less, 6 or less, 4 or less or 3 or less c may be an integer of 2 or greater or 3 or greater. [0024] Useful as 1 , 1 -disubstited activated alkenes in the compositions disclosed are polyesters prepared from 1 ,1 -disubstited activated alkenes. The polyesters may have one or greater or, two or greater of chains, as described herein. The chains may include the residue of one or more 1 ,1 -diester-1 -alkenes. The chains may include the residue or one or more dihydrocarbyl dicarboxylates. The chains may contain the residue of one or more diols and one or more diesters wherein the diesters comprise one or more 1 ,1 -diester- 1 -alkenes, the residue of the one or more diols and the one or more 1 , 1 -diester-1 alkenes and optionally one or more dihydrocarbyl dicarboxylates may be randomly disposed along the chains. The polyester may have diols, diesters, alkene groups, or a combination pendant to the polyester chain. Dihydrocarbyl dicarboxylates are diesters having a hydrocarbylene group between the ester groups wherein a double bond is not bonded to a carbon atom which is bonded to two carbonyl groups of the diester. The one or more dihydrocarbyl dicarboxylates comprise one or more of aromatic dicarboxylates, aliphatic dicarboxylates and cycloaliphatic dicarboxylates or may be one or more dihydrocarbyl dicarboxylates wherein one of the hydrocarbyl groups is aliphatic, cycloaliphatic or aromatic and the other is selected from another class of aliphatic, cycloaliphatic or aromatic. The one or more dihydrocarbyl dicarboxylates comprise one or more of aromatic dicarboxylates having 8 to 14 carbon atoms in the backbone, aliphatic dicarboxylates having 1 to 12 carbon atoms in the backbone and cycloaliphatic dicarboxylates having 8 to 12 carbon atoms in the backbone. The one or more dihydrocarbyl dicarboxylates comprise one or more malonates, terephthalates, phthalates, isophthalates, naphthalene-2, 6-dicarboxylates, 1 ,3-phenylene dioxydiacetates, cyclohexane-dicarboxylates, cyclohexanediacetates, diphenyl-4, 4'- dicarboxylates, succinates, glutarates, adipates, azelates, sebacates, or mixtures thereof. The one or more dihydrocarbyl dicarboxylates may comprise one or more malonates. The one or more dihydrocarbyl dicarboxylates correspond to formula 3: 3 wherein R ¹ is as previously described; and

R ³ is separately in each occurrence a hydrocarbylene group having two bonds to the carbonyl groups of the diester wherein the hydrocarbylene group may contain one or more heteroatoms. R ³ may be separately in each occurrence arylene, cycloalkylene, alkylene or alkenylene. R ³ may be separately in each occurrence C s-i4 arylene, C 8-12 cycloalkylene, C 1-12 alkylene or C 2-12 alkenylene. R ³ may be methylene. The reactants may include a methylene malonate. The methylene malonates may be any methylene malonate that may be transesterified.

[0025] The backbone of polyester macromers contain a sufficient number of repeating units comprising the residue of at least one diester and one diol to facilitate the use of the polyester macromers as disclosed herein. The number of repeating units comprising the residue of at least one diester and one diol in polyester macromers may be 2 or greater, 4 or greater or 6 or greater. The number of repeating units comprising the residue of at least one diester and one diol in polyester macromers may be 20 or less, 14 or less, 10 or less, 8 or less, 6 or less, or 4 or less. The diesters in some polyester macromers can be all 1 ,1 -diester-1 -alkenes. The diesters in some polyesters can be 1 ,1 -diester-1 -alkenes and dihydrocarbyl dicarboxylates. The molar ratio of 1 ,1- diester-1 -alkenes and dihydrocarbyl dicarboxylates in some polyester macromers is selected to provide the desired degree of crosslinking in structures prepared from the polyesters. The molar ratio of 1 ,1 -diester- 1-alkenes and dihydrocarbyl dicarboxylates in some polyesters may be 1 :1 or greater, 6:1 or greater or 10:1 or greater. The molar ratio of 1 ,1 -diestersubstituted- 1-alkenes and dihydrocarbyl dicarboxylates in some polyesters may be 15:1 or less, 10:1 or less, 6:1 or less or 4 :1 or less. The polyester may exhibit a number average molecular weight of about 700 or greater, about 900 or greater, about 1000 or greater or about 1200 or greater. The polyesters may exhibit a number average molecular weight of about 3000 or less, about 2000 or less or about 1600 or less. Number average molecular weight as used herein is determined dividing total weight of all the polymer molecules in a sample, by the total number of polymer molecules in a sample. The polydispersity of the polyesters may be about 1 .05 or greater or about 1 .5 or greater. The polydispersity of the polyesters may be about 4.5 or less, about 2.5 or less, about 2.5 or less or about 1 .5 or less. For calculating the polydispersity the weight average molecular weight is determined using gel permeation chromatography using polymethylmethacrylate standards. Polydispersity is calculated by dividing the measured weight average molecular weight (Mv) by the number average molecular weight (Mn), that is Mv/ Mn.

[0026] The polyesters disclosed may be prepared from 1 ,1 -diester-1 -alkenes, diols, polyols and/or dihydrocarbyl dicarboxylates. The choice of specific ingredients, ratios of ingredients and sequence of process steps impact the final structure of the polyesters. The polyesters disclosed may be prepared as disclosed in US 9,617,377 incorporated herein by reference in its entirety. [0027] 1 , 1 -disubstited activated alkenes may comprise any one or more of the 1 , 1 -disubstited activated alkenes disclosed herein. An exemplary composition may comprise i) a plurality of polyesters disclosed herein; ii) one or more multifunctional monomers containing the residue of one or more polyols and one or more 1 ,1 -diester-1 -alkenes, wherein the multifunctional monomers have substantially all of the hydroxyl groups of the polyols replaced with the 1 ,1- diester-1 -alkenes; and iii) optionally, one or more 1 ,1 -diester alkenes.

[0028] The 1 ,1 -disubstited activated alkenes may be present in the curable compositions in an amount such that such compounds form a polymer matrix in each layer and form cohesive bonds between the layers. The 1 ,1 -disubstited activated alkenes may be present in the curable compositions in an amount of about 5 percent by weight or greater based on the weight of the curable composition, about 10 percent by weight or greater, about 30 percent by weight or greater or about 50 percent by weight or greater. The 1 ,1 -disubstited activated alkenes may be present in the curable compositions in an amount of about 99 percent by weight or less based on the weight of the curable composition, about 90 percent by weight or less, about 50 percent by weight or less or about 10 percent by weight or less. [0029] The curable compositions may include one or more second compounds which are free radically polymerizable when exposed to free radicals and radiation. The one or more second compounds may be any compounds that polymerize when exposed to free radicals and radiation. Exemplary second compounds include (meth)acrylates, monovinylidene aromatic monomers, conjugated dienes, unsaturated nitriles, vinylidene halides, vinyl acetates, cyanoacrylates, maleates, fumarates, maleimides, itaconates, and the like. The second compound may be a (meth)acrylate, acrylate, acrylic compound, or any combination thereof. (Meth) acrylate as used herein refers to compounds having a vinyl group bonded to the carbonyl moiety of an alkyl ester wherein the carbon of the vinyl group bonded to the carbonyl group further has a hydrogen or a methyl group bonded thereto. The term (meth) as used in this context refers to compounds having either of a hydrogen or methyl group on the carbon of the vinyl group bonded to the carbonyl group. (Meth)acrylates useful include those that correspond to the formula 4:

[0030] wherein R ^a is separately in each occurrence H or — CH ₃ ; and R ^b may be a C i to C 30 alkyl group or C 1-10 alkyl group wherein the alkyl group may contain a nucleophilic group as described herein. The nucleophilic group may be capable of initiating anionic polymerization. Examples of the one or more (meth)acrylates include lower alkyl (meth)acrylates, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)(acrylate) and hexyl (meth) acrylate; hydroxyethyl methacrylate, hydroxypropyl methacrylate, aminoalkyl (meth)acrylate, N-alkyl aminoalkyl (meth)acrylate, N,N-dialkyl aminoalkyl (meth)acrylate; urieido (meth)acrylate; (meth)acrylonitrile and (meth)acrylamide. [0031] The one or more second compounds may be present in the curable compositions in an amount such that such compounds participate in the formation of a polymer matrix in each layer and introduces desirable properties into the matrix. The one or more second compounds may be present in the curable compositions in an amount of about 1 .0 percent by weight or greater based on the weight of the curable composition, about 5.0 percent by weight or greater or about 10.0 percent by weight or greater. The one or more second compounds may be present in the curable compositions in an amount of about 90.0 percent by weight or less based on the weight of the curable composition, about 50.0 percent by weight or less or about 30.0 percent by weight or less. [0032] The second compounds may be vinylidene substituted aromatic monomers that comprise vinylidene, alkenyl groups bonded directly to aromatic structures. The vinylidene substituted aromatic monomers may contain one or more aromatic rings, may contain one or two aromatic rings, or may contain one aromatic ring. The aromatic rings can be unsubstituted or substituted with a substituent that does not interfere with polymerization of the vinylidene substituted aromatic monomers, or the fabrication of the polymers formed into desired structures. The substituents may be halogens or alkyl groups, such as bromine, chlorine or Ci to C ₄ alkyl groups; or a methyl group. Alkenyl groups comprise straight or branched carbon chains having one or more double bonds, or one double bond. The alkenyl groups useful for the vinylidene substituted aromatic monomers may include those that when bonded to an aromatic ring are capable of polymerization to form copolymers. The alkenyl groups may have 2 to 10 carbon atoms, 2 to 4 carbon atoms or 2 carbon atoms. Exemplary vinylidene substituted aromatic monomers include styrene, alpha methyl styrene, N-phenyl-maleimide and chlorinated styrenes; or alpha-methyl styrene and styrene. The vinylidene substituted aromatic monomers may be mono-vinylidene aromatic monomers, which contain one unsaturated group.

[0033] The second compounds may comprise one or more unsaturated nitriles. Unsaturated nitriles include, but are not limited to, acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile and mixtures thereof. The unsaturated nitrile may be acrylonitrile. The second compounds may be conjugated 1 ,3 dienes, such as butadiene or isoprene. The second compounds may comprise Sorbic acid esters, which comprise a diene with a carboxylic ester.

[0034] The curable compositions may include one or more third compounds which are anionically polymerizable, participates in the formation of a polymer matrix in each layer and are capable of forming cohesive bonds between the layers. The one or more third compounds may be any compounds that polymerize when exposed to the photolatent bases and radiation. Exemplary third compounds include epoxides, isocyanate functional compounds, and the like. The one or more third compounds may be present in the curable compositions in an amount such that such compounds participates in the formation of a polymer matrix in each layer, introduce desired properties into the matrix and/or form cohesive bonds between the layers. The one or more third compounds may be present in the curable compositions in an amount of about 1.0 percent by weight or greater based on the weight of the curable composition, about 5.0 percent by weight or greater or about 10.0 percent by weight or greater. The one or more third compounds may be present in the curable compositions in an amount of about 90 percent by weight or less based on the weight of the curable composition, about 50 percent by weight or less or about 30 percent by weight or less. [0035] The compositions may include one or more fourth compounds which may comprise one or more compounds, oligomers or polymers which have functional groups which are capable of Michael adding to alkene groups in the presence of an amine. The fourth compounds may be referred to as Michael addition donors. These functional groups contain active hydrogen groups that react with an electrophilic unsaturated group such as the alkene groups from the 1 ,1 -diactives alkene compounds. The Michael addition donor groups may comprise amines, hydroxyls, thiols, or mixtures thereof. The Michael addition donor groups may comprise thiols and/or hydroxyls. It may be desirable to avoid the amine functional groups because they could initiate anionic polymerization and render the compositions as disclosed herein unstable. Any compounds with the Michael Addition donor groups may be utilized as the fourth compounds. The fourth compounds may be polymers which contain pendant Michael Addition Donor groups. The polymers having pendant Michael Addition donor groups may be acrylic, polycarbonate, styrene acrylonitrile, siloxane polyester, polysulfides or polyether backbones and the like. Exemplary polymers having pendant Michael Addition donor groups include one or more of acrylic polyols, amine modified acrylic polyols, polycarbonate polyols, modified acrylic copolymer polyols, seed oil polyols, polyether polyols, polyester polyols, polysulfides and siloxane polyols. The one or more polymers having pendant Michael Addition donor groups may comprise one or more acrylic polyols or amine modified acrylic polyols, and the like. Exemplary acrylate compounds containing Michael donor groups include hydroxyl-ethyl methacrylate, hydroxy butylacrylate, hydroxyethyl acrylate, and the like. Styrene acrylonitrile based polymers containing Michael Addition Donors may be prepared by reacting styrene, acrylonitrile and a polyalkylene oxide containing an active hydrogen containing functional group such as an amine, hydroxyl or thiol group. The polyalkylene oxide may be a polypropylene oxide. The active hydrogen containing functional groups may be amino or hydroxyl, or may be hydroxyl. The one or more fourth compounds may be present in the curable compositions in an amount of about 1.0 percent by weight or greater based on the weight of the curable composition, about 5.0 percent by weight or greater or about 10.0 percent by weight or greater. The one or more fourth compounds may be present in the curable compositions in an amount of about 90 percent by weight or less based on the weight of the curable composition, about 50 percent by weight or less or about 30 percent by weight or less. [0036] The compositions contain one or more photolatent bases. A photolatent base is a compound that upon exposure to radiation releases a base, such as an amine, guanidine amidine or a carbanion, that is capable of initiating anionic polymerization. The photolatent base may also upon exposure to radiation may generate free radicals which initiate free radical polymerization. Any compound that forms or releases an amine or a carbanion which initiates anionic polymerization upon exposure to radiation may be used. The photolatentbases may absorb light and photocleave in a wavelength range from about 200 nm to about 650 nm. Any compound that forms or releases an amine or a carbanion which initiates anionic polymerization and form free radicals to initiate free radical polymerization upon exposure to radiation may be used. The photolatentbases may release alkyl amines, compounds with amidine structures or guanidines. The photolatent bases may release alkyl amines. The alkyl amines may be monoalkyl amines, primary amines, dialkyl amines, secondary amines or trialkyl amines, tertiary amines. Photolatent bases include photocleavable carbamates (e.g., 9-xanthenylmethyl, fluorenylmethyl, 4- methoxyphenacyl, 2,5-dimethylphenacyl, benzyl, and others), which have been shown to generate primary or secondary amines after photochemical cleavage. Other photolatent bases which generate primary or secondary amines include certain O-acyloximes, sulfonamides, and formamides. Acetophenones, benzophenones, and acetonaphthones bearing quaternary ammonium undergo photocleavage to generate tertiary amines in the presence of a variety of counter cations (borates, dithiocarbamates, and thiocyanates). Examples of these photolatent ammonium salts are N-(benzophenonemethyl)tri-N-alkyl ammonium tetraphenylborates. Sterically hindered a-aminoketones generate tertiary amines. Exemplary photolatent bases useful for practicing the present disclosure include 5-benzyl-1 ,5-diazabicyclo[4.3.0]nonane, 5- (anthracen-9-yl-methyl)-1 ,5-diaza[4.3.0]nonane, 5-(2'-nitrobenzyl)-1 ,5-diazabicyclo

[4.3.0]nonane, 5-(4'-cyanobenzyl)-1 ,5-diazabicyclo[4.3.0]nonane, 5-(3'-cyanobenzyl)-1 ,5-diaza bicyclo[4.3.0]nonane, 5-(anthraquinon-2-yl-methyl)-1 ,5-diaza[4.3.0]nonane, 5-(2'-chlorobenzyl)- 1 ,5-diazabicyclo[4.3.0]nonane, 5-(4'-methylbenzyl)-1 ,5-diazabicyclo[4.3.0]nonane, 5-(2',4',6'-tri methylbenzyl)-1 ,5-diazabicyclo[4.3.0]nonane, 5-(4'-ethenylbenzyl)-1 ,5-diazabicyclo [4.3.0] nonane, 5-(3'-trimethylbenzyl)-1 ,5-diazabicyclo[4.3.0]nonane, 5-(2',3'-dichlorobenzyl)-1 ,5-diaza bicyclo[4.3.0]nonane, 5-(naphth-2-yl-methyl-1 ,5-diazabicyclo[4.3.0]nonane, 1 ,4-bis(1 ,5- diazabicyclo [4.3.0]nonanylmethyl)benzene, 8-benzyl-1 ,8-diazabicyclo[5.4.0]undecane, 8-benzyl -6-methyl-1 ,8-diazabicyclo[5.4.0]undecane, 9-benzyl-1 ,9-diazabicyclo[6.4.0]dodecane, 10- benzyl-8-methyl-1 , 10-diazabicyclo[7.4.0]tridecane, 11 -benzyl- 1 ,11 -diazabicyclo [8.4.0]tetra decane, 8-(2'-chlorobenzyl)-1 ,8-diazabicyclo[5.4.0]undecane, 8-(2',6'-dichlorobenzyl)-1 ,8-diaza bicyclo[5.4.0]undecane, 4-(diazabicyclo[4.3.0]nonanylmethyl)-1 ,1 '-biphenyl, 4,4'-bis(diazabicyclo [4.3.0]nonanylmethyl)-11 '-biphenyl, 5-benzyl-2-methyl-1 ,5-diazabicyclo[4.3.0]nonane, 5-benzyl- 7-methyl-1 ,5,7-triazabicyclo[4.4.0]decane, and combinations thereof. An example of a photolatent base is available from BASF under the trade designation “CGI-90”, which is reported to be 5- benzyl-1 ,5-diazabicyclo[4.3.0]nonane (see, e.g., WO 2014/176490 (Knapp et al.)), which generates 1 ,5-diazabicyclo[4.3.0]non-5-ene (DBN) upon exposure to radiation (see, e.g., US2013/0345389 (Cai et al), 2-benzyl-1-(3,5-dimethoxyphenyl)-2-(dimethylamino)butan-1 -one available from BASF under the trade designation CGI 277, p-(Ethylthio)phenyl methylcarbamate and 6-Nitroveratryl chloroformate diethyl amine. A carbanion is an anion in which carbon is trivalent (forms three bonds) and bears a formal negative charge (in at least one significant resonance form. A carbanion is the conjugate base of a carbon acid. Carbanions may be formed from deprotonation of alkanes (at an sp3 carbon), alkenes (at an sp2 carbon), arenes (at an sp2 carbon), and alkynes (at an sp carbon) and are known as alkyl, alkenyl (vinyl), aryl, and alkynyl (acetylide) anions, respectively.

[0037] The photolatent base is present in an amount sufficient to provide an amine upon photocleavage in an amount sufficient to initiate cure anionic cure of the one or more 1 ,1- disubstituted activated alkene compounds and any third compounds present. The photolatent base is present in an amount sufficient to provide an amine upon photocleavage in an amount sufficient to initiate cure anionic polymerization of the one or more 1 , 1 -disubstituted activated alkene compounds and any third compounds present and to generate sufficient free radicals to initiate free radical polymerization of the one or more 1 ,1 -disubstituted activated alkene compounds and one or more second compounds. The photolatent base may be a compound that generates a carbanion, for instance a thioxanthone-based compound, which generates a carbanion via decarboxylation under LED light irradiation. The photolatent base may be present in an amount of about 0.05 percent by weight or greater of the polymerizable compositions, about 0.1 percent by weight or greater, about 0.5 percent by weight or greater or about 1 .0 percent by weight or greater. The photolatent base may be present in an amount of about 20.0 percent by weight or less of the polymerizable compositions, about 10 percent by weight or less, about 5.0 percent by weight or less or about 2.0 percent by weight or less.

[0038] The compositions contain one or more acidic compounds which slow the anionic cure of the compositions when the photolatent base is photocleaved to release an amine which initiates anionic cure. Any acidic compound which slows the anionic cure may be utilized. The polymerization may be slowed such that anionic polymerization continues beyond exposure to radiation. Exemplary classes of acidic compounds include one or more of carboxylic acids, sulfonic acids, mineral acids and phosphorus oxoacids or esters. The acidic compound may be one or more of sulfuric acid, alkyl substituted aryl sulfonic acids, alkyl sulfonic acids and fluorinated carboxylic acids or esters thereof. Exemplary acidic compounds include one or more of dodecylbenzenesulfonic acid, p-toluenesulfonic acid, methane sulfonic acid, sulfuric acid and trifluoroacetic acid or esters thereof. The acidic compounds that inhibit anionic polymerization are present in an amount sufficient to slow down the cure of anionic polymerization. The equivalents of the acidic compounds present need to be less than the equivalents of the base released as a result of photocleavage of the photolatent base. The acidic compound may be present in an amount of about 0.0001 percent by weight or greater of the polymerizable compositions, about 0.001 percent by weight or greater, about 0.01 percent by weight or greater or about 0.05 percent by weight or greater. The acidic compound may be present in an amount of about 5.0 percent by weight or less of the polymerizable compositions, about 2.0 percent by weight or less, about 1 .0 percent by weight or less or about 0.5 percent by weight or less.

[0039] The composition may contain a free radical photoinitiator. The free radical initiator may be present wherein the photolatent base does not form free radicals upon exposure to radiation, when no photolatent base is present or may be present to provide additional free radicals in addition to those generated by the photolatent base. Any free radical photoinitiator that generates free radicals may be used. A photoinitiator is a compound that undergoes a photoreaction on absorption of light, producing reactive species. The reactive species which are generated then initiate polymerization of the reactive components of the curable composition. Such polymerization (curing) involves reaction of the carbon-carbon double bonds present in such components. The reactive species may be, for example, a free radical species. Exemplary classes of free radical photoinitiators include one or more of alpha aminoketones, alpha hydroxyketones, phosphine oxides, phenylglyoxalates, thioxanthones, benzophenones, benzoin ethers, oxime esters, acetophenones, cyanine borates, fluorone dyes with borates or amines, dyes that can be excited by UV and visible parts of the electromagnetic spectrum such as fluorone dyes, cyanine and phthalocyanine dyes, coumarins, peroxides and azo compounds or mixtures thereof. Exemplary photoinitiators include, but are not limited to 2- methylanthraquinone, 2- ethylanthraquinone, 2-chloroanthraquinone, 2 benzyanthraquinone, 2-t- butylanthraquinone, 1 ,2- benzo-9, 10-anthraquinone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, alpha-methylbenzoin, alpha-phenylbenzoin, Michler's ketone, benzophenone, 4,4'-bis-(diethylamino) benzophenone, acetophenone, 2,2 diethyloxyacetophenone, diethyloxyacetophenone, 2-isopropylthioxanthone, thioxanthone, diethyl thioxanthone, acetylnaphthalenes, ethyl-p-dimethylaminobenzoate, benzil ketone, a-hydroxy keto, 2,4,6- trimethylbenzoyldiphenyl phosphinoxide, benzyl dimethyl ketal, benzil ketal (2,2-dimethoxy-l,2- diphenylethanone), 1 -hydroxycylclohexyl phenyl ketone, 2-methyl-l -[4-(methylthio) phenyl]-2- morpholinopropanone-1 , 2-hydroxy-2-methyl-l-phenyl-propanone, oligomeric a-hydroxy ketone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl-4-dimethylamino benzoate, ethyl(2,4,6- trimethylbenzoyl)phenyl phosphinate, anisoin, anthraquinone, anthraquinone-2-sulfonic acid, sodium salt monohydrate, (benzene) tricarbonylchromium, benzil, benzoin isobutyl ether, benzophenone/l -hydroxycyclohexyl phenyl ketone, 50/50 blend, 3, 3', 4,4'- benzophenonetetracarboxylic dianhydride, 4-benzoylbiphenyl, 2-benzyl-2-(dimethylamino)-4'- morpholinobutyrophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'- bis(dimethylamino)benzophenone, camphorquinone, 2-chlorothioxanthen-9-one, dibenzo suberenone, 4,4'-dihydroxybenzophenone, 2,2-dimethoxy-2-phenylacetophenone, 4- (dimethylamino)benzophenone, 4,4'-dimethylbenzil, 2,5-dimethylbenzophenone,3,4- dimethyl benzophenone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide 2-hydroxy-2- methylpropio phenone, 50/50 blend, 4'-ethoxyacetophenone, 2,4,6- trimethylbenzoyldiphenylphophine oxide, phenyl bis(2, 4, 6-trimethyl benzoyl)phosphine oxide, ferrocene, 3'-hydroxyacetophenone, 4'- hydroxyacetophenone, 3-hydroxybenzophenone, 4- hydroxybenzophenone, 1 -hydroxy cyclohexyl phenyl ketone, 2-hydroxy-2-methylpropiophenone, 2- methylbenzophenone, 3-methyl benzophenone, methybenzoylformate, 2-methyl-4'-(methylthio)-2- morpholinopropiophenone, phenanthrenequinone, 4'-phenoxyacetophenone,(cumene)cyclopentadienyl iron(ii) hexafluoro phosphate, 9, 10-diethoxy and 9,10- dibutoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, thioxanthen-9-one and combinations thereof. Exemplary combinations of suitable photoinitiators include blends of 2-hydroxy-2-methyl- 1 -phenyl- 1-propanone, 2,4,6-trimethyl benzoylphenylphosphinic acid ethyl ester and phenylbis(2,4,6-trimethylbenzoyl) phosphine oxide and blends of 2-hydroxy-2-methyl-l -phenyl- 1- propanone and diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide. The one or more photoinitiators may be selected from 1 ,1 -dibenzoyl ferrocene, 2-methyl-4’-(methylthio)-2-morphlinopropiophenone, the salt of tributylamine and tetraphenylborate, isopropylthioxanthone, or a combination thereof.

[0040] The photoinitiator may be added to the composition including 1 ,1-diactivted alkene compounds in an amount sufficient to initiate free radical polymerization. The free radical photoinitiator may be present in an amount of about 0.05 percent by weight or greater of the polymerizable compositions, about 0.1 percent by weight or greater, about 0.5 percent by weight or greater or about 1 .0 percent by weight or greater. The free radical photoinitiator may be present in an amount of about 10.0 percent by weight or less of the polymerizable compositions, about 6.0 percent by weight or less, about 5.0 percent by weight or less or about 2.0 percent by weight or less.

[0041] The composition may contain one or more photosensitizers. Photosensitizers are compounds that when used in conjunction with a photolatent base and/or free radical photoinitiator, improve or allow the photocatalysis or photoinitiation of a base-catalyzed polymerization and/or free radical polymerization at the longer wavelengths than the absorbance of the photolatent base or photoinitiator irradiation with light of the wavelength of interest; in this case 380 nm to 800 nm, 390 nm to 510 nm or 400 nm to 500 nm. A photosensitizer may be a compound having an absorption spectrum that overlaps or closely matches the emission spectrum of the radiation source to be used and that can, for example, improve the energy transfer to the photolatent base. Blue light can be considered, in some embodiments to have a wavelength range of 420 nm to 495 nm. Photosensitizers shift or broaden the spectral sensitivity of a system. Exemplary classes of photosensitizers include aromatic carbonyl compounds, for example benzophenone, thioxanthone, anthraquinone and 3-acylcoumarin derivatives or dyes such as eosine, rhodamine and erythrosine dyes. Additional exemplary photoinitiators include: thioxanthones, such as thioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 1-chloro-4- propoxythioxanthone, 2-dodecylthioxanthone, 2,4-diethylthioxanthone, 2,4-dimethyl thioxanthone, 1-methoxycarbonylthioxanthone, 2-ethoxycarbonylthioxanthone, 3-(2-methoxy ethoxycarbonyl)-thioxanthone, 4-butoxycarbonylthioxanthone, 3-butoxycarbonyl-7-methyl thioxanthone, 1 -cyano-3-chlorothioxanthone, 1-ethoxycarbonyl-3-chlorothioxanthone, 1 -ethoxy carbonyl-3-ethoxythioxanthone, 1 -ethoxycarbonyl-3-aminothioxanthone, 1 -ethoxycarbonyl-3- phenylsulfurylthioxanthone, 3,4-di-[2-(2-methoxyethoxy)ethoxycarbonyl]-thioxanthone, 1 ,3- dimethyl -2-hydroxy-9H-thioxanthen-9-one 2-ethylhexylether, 1-ethoxycarbonyl-3-(1 -methyl-1 - morpholinoethyl)-thioxanthone, 2-methyl-6-dimethoxymethyl-thioxanthone, 2-methyl-6-(1 ,1- dimethoxybenzyl)-thioxanthone, 2-morpholinomethylthioxanthone, 2-methyl-6-morpholino methylthioxanthone, N-allylthioxanthone-3,4-dicarboximide, N-octylthioxanthone-3,4-dicarbox imide, N-(1 ,1 ,3,3-tetramethylbutyl)-thioxanthone-3,4-dicarboximide, 1 -phenoxythioxanthone, 6- ethoxycarbonyl-2-methoxythioxanthone, 6-ethoxycarbonyl-2-methylthioxanthone, thioxanthone- 2-carboxylic acid polyethyleneglycol ester, 2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthon-2- yloxy)-N,N,N-trimethyl-1-propanaminium chloride; 2. Benzophenones, such as benzophenone, 4- phenyl benzophenone, 4-methoxy benzophenone, 4,4'-dimethoxy benzophenone, 4,4'-dimethyl benzophenone, 4,4'-dichlorobenzophenone 4,4'-bis(dimethylamino)-benzophenone, 4,4'-bis (diethylamino)benzophenone, 4,4'-bis(methylethylamino)benzophen-one, 4,4'-bis(p-isopropyl phenoxy)benzophenone, 4-methyl benzophenone, 2,4,6-trimethyl-benzophenone, 4-(4-methyl thiophenyl)-benzophenone, 3,3'-dimethyl-4-methoxy benzophenone, methyl-2-benzoylbenzoate, 4-(2-hydroxyethylthio)-benzophenone, 4-(4-tolylthio)-benzophenone, 1 -[4-(4-benzoyl-phenyl sulfanyl)-phenyl]-2-methyl-2-(toluene-4-sulfonyl)-propan-1-o ne, 4-benzoyl-N,N,N-trimethyl benzenemethanaminium chloride, 2-hydroxy-3-(4-benzoylphenoxy)-N,N,N-trimethyl-1 - propanaminium chloride monohydrate, 4-(13-acryloyl-1 ,4,7, 10,13-pentaoxamidecyl)-benzo phenone, 4-benzoyl-N, N-dimethyl-N-[2-(1 -oxo-2-propenyl)oxy]ethyl-benzenemethanaminium chloride; Coumarins, such as Coumarin 1 , Coumarin 2, Coumarin 6, Coumarin 7, Coumarin 30, Coumarin 102, Coumarin 106, Coumarin 138, Coumarin 152, Coumarin 153, Coumarin 307, Coumarin 314, Coumarin 314T, Coumarin 334, Coumarin 337, Coumarin 500, 3-benzoyl coumarin, 3-benzoyl-7-methoxycoumarin, 3-benzoyl-5,7-dimethoxycoumarin, 3-benzoyl-5,7- dipropoxycoumarin, 3-benzoyl-6,8-dichlorocoumarin, 3-benzoyl-6-chloro-coumarin, 3,3'-carbonyl -bis[5,7-di(propoxy)coumarin], 3,3'-carbonyl-bis(7-methoxycoumarin), 3,3'-carbonyl-bis(7- diethylamino-coumarin), 3-isobutyroylcoumarin, 3-benzoyl-5,7-dimethoxy-coumarin, 3-benzoyl- 5,7-diethoxy-coumarin, 3-benzoyl-5,7-dibutoxycoumarin, 3-benzoyl-5,7-di(methoxyethoxy)- coumarin, 3-benzoyl-5,7-di(allyloxy)coumarin, 3-benzoyl-7-dimethylaminocoumarin, 3-benzoyl-7- diethylaminocoumarin, 3-isobutyroyl-7-dimethylaminocoumarin, 5,7-dimethoxy-3-(1 -naphthoyl)- coumarin, 5,7-diethoxy-3-(1-naphthoyl)-coumarin, 3-benzoylbenzo[f]coumarin, 7-diethylamino-3- thienoylcoumarin, 3-(4-cyanobenzoyl)-5,7-dimethoxycoumarin, 3-(4-cyanobenzoyl)-5,7- dipropoxycoumarin, 7-dimethylamino-3-phenylcoumarin, 7-diethylamino-3-phenylcoumarin, the coumarin derivatives disclosed in JP 09-179299-A and JP 09-325209-A, for example 7-[{4-chloro- 6-(diethylamino)-S-triazine-2-yl}amino]-3-phenylcoumarin; 4. 3-(aroylmethylene)-thiazolines, such as 3-methyl-2-benzoylmethylene^-naphthothiazoline, 3-methyl-2-benzoylmethylene- benzothiazoline, 3-ethyl-2-propionylmethylene-b-naphthothiazoline; Rhodanines, such as 4- dimethylaminobenzalrhodanine, 4-diethylaminobenzalrhodanine, 3-ethyl-5-(3-octyl-2-benzo thiazolinylidene)-rhodanine; other Compounds, such as acetophenone, 3-methoxyacetophenone, 4-phenylacetophenone, benzil, 4,4'-bis(dimethylamino)benzil, 2-acetylnaphthalene, 2-naphth aldehyde, dansyl acid derivatives, 9,10-anthraquinone, anthracene, pyrene, aminopyrene, perylene, phenanthrene, phenanthrenequinone, 9-fluorenone, dibenzosuberone, curcumin, xanthone, thiomichler's ketone, a-(4-dimethylaminobenzylidene) ketones, e.g. 2,5-bis(4- diethylaminobenzylidene)cyclopentanone, 2-(4-dimethylamino-benzylidene)-indan-1 -one, 3-(4- dimethylamino-phenyl)-1 -indan-5-yl-propenone, 3-phenylthiophthalimide, N-methyl-3,5-di (ethylthio)-phthalimide, N-methyl-3,5-di(ethylthio)phthalimide, phenothiazine, methylpheno thiazine, amines, e.g. N-phenylglycine, ethyl 4-dimethylaminobenzoate, butoxyethyl 4-dimethyl aminobenzoate, 4-dimethylaminoacetophenone, triethanolamine, methyldiethanolamine, dimethylaminoethanol, 2-(dimethylamino)ethyl benzoate, poly(propylenegylcol)-4-(dimethyl amino) benzoate. The weight ratio of photolatent bases and / free radical photoinitiators to the weight of photosensitizers may be in a range from 0.5:1 to 10:1 or 1 :1 to 5:1 .

[0042] The compositions may contain one or more amines that initiate anionic polymerization. Such amines may be present to initiate or enhance the initiation of anionic polymerization. The amines may be used in two-part compositions wherein the amine is in a separate part from compounds that may polymerize by anionic polymerization. Any amine which initiates anionic polymerization may be used. Exemplary amines include secondary aliphatic amines; piperidene, piperazine, N-methylpiperazine, dibutylamine, morpholine, diethylamine, pyridine, triethylamine, tripropylamine, triethylenediamine, N,N-dimethylpiperazine, butylamine, penty lamine, hexylamine, heptylamine, nonylamine, decylamine, amidines and guanidines. The amine may be present in an amount of about 0.05 percent by weight or greater of the polymerizable compositions, about 0.1 percent by weight or greater or about 0.5 percent by weight or greater. The amine may be present in an amount of about 2.0 percent by weight or less of the polymerizable compositions, about 1.0 percent by weight or less or about 0.5 percent by weight or less.

[0043] The composition may contain a radical initiator, which is not generally used as a free radical photoinitiator. Any radical initiator that enhances polymerization may be used. These radical initiators may be used in two-part systems wherein the radical initiator is in a different part from compounds which polymerize when exposed to free radicals. Exemplary classes of initiators include free radical initiators such as peroxide and azo compounds which will accelerate free radical polymerization. Exemplary initiators include but are not limited to tertiary butyl peroxyacetate, dibenzoyl peroxide, dilauroyl peroxide, t-butylhydroperoxide, ditertiary-butyl peroxide, cumene hydroperoxide, dicumylperoxide, 1 ,1-bis(tertiary-butylperoxy)-3, 3, 5-trimethyl- cyclohexane, t-butylperoxybenzoate, 1 ,1-bis(t-butylperoxy)-cyclohexane, benzoylperoxide, succinoylperoxide and t-butylperoxypivilate, and azo compounds such as azobisisobutyro-nitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbo-nitrile, azobismethyl isolactate and azo biscyanovalerate. The free radical initiators may be utilized in a sufficient amount to enhance free radical polymerization. The radical initiators may be present in an amount of about 0.001 percent by weight or greater based on the weight of the curable composition, about 0.002 percent by weight or greater or about 0.003 percent by weight or greater. The radical initiators may be present in an amount of about 0.1 percent by weight or less based on the weight of the curable composition, about 0.08 percent by weight or less or about 0.05 percent by weight or less.

[0044] Other ingredients may be added to the mixtures of compounds formed herein for radical cure, anionic cure, or both in the formation of 3D printed articles. Each of these ingredients are disclosed herein.

[0045] The curable composition may include one or more fillers that may be one or more of particles, fibers, pigments, or hollow spheres. The fillers may be blended with the curable composition to form 3D printed articles. The fillers may provide desirable properties for 3D printed articles such as better shapes, aesthetics, colors, impact stability, or a combination thereof. The fillers may comprise any fillers that when dispersed in a final composition and provide improved coefficient of linear expansion, modulus, impact, heat resistance and the like. Exemplary fiber types include polymeric fibers, carbon fibers, glass fibers and the like.

[0046] The curable composition may comprise one or more free radical stabilizers. The one or more free radical stabilizers may be present in sufficient amount to prevent premature polymerization. The free radical polymerization stabilizers may be present in an amount of about 10 ppm or greater based on the weight of the total composition, about 100 ppm by weight or greater or about 1000 ppm by weight or greater. The free radical polymerization stabilizers may be present in an amount of about 10,000 ppm by weight or less based on the weight of the total composition, about 8000 ppm by weight or less about 5000 ppm by weight or less or about 1000 parts per million by weight or less. The free radical inhibitors that may be used include: tocopherol (e.g., including vitamin E), 4-tert-Butylpyrocatechol; tert-Butylhydroquinone; 1 ,4-Benzoquinone; 6-tert-Butyl-2,4-xylenol; 2-tert-Butyl-1 ,4-benzoquinone; 2,6-Di-tert-butyl-p-cresol; 2,6-Di-tert- butylphenol; Hydroquinone; 4-Methoxyphenol; Phenothiazine; 2,2’-methylenebis(6-tert-butyl-4- methylphenol) or a combination thereof. Free radical stabilizers preferably include phenolic compounds (e.g., 4-methoxyphenol, mono methyl ether of hydroquinone (“MeHQ”) butylated hydroxytoluene (“BHT”)). Stabilizer packages for 1 ,1 -disubstituted alkenes are disclosed in U.S. Patent No. 8,609,885 and U.S. Patent No. 8,884,051 , each incorporated by reference. Additional free radical polymerization inhibitors are disclosed in U.S. Patent No. 6,458,956 which is hereby incorporated by reference. Generally, only minimal quantities of a stabilizer are needed and, in certain embodiments only about 5000 parts-per-million (“ppm”) or less can be included. In certain embodiments, a blend of multiple stabilizers can be included; for example, a blend of anionic stabilizers (MSA) and free radical stabilizers (MeHQ).

[0047] The curable compositions may include anionic polymerization stabilizers which are electrophilic compounds that scavenge electrons from the composition or growing polymer chain. The use of anionic polymerization stabilizers can terminate additional polymer chain propagation. Exemplary anionic polymerization stabilizers are acids, exemplary acids are carboxylic acids, sulfonic acids, phosphoric acids and the like. Exemplary stabilizers include liquid phase stabilizers, such as methanesulfonic acid (“MSA”), and vapor phase stabilizers, such as trifluoroacetic acid (“TFA”). The anionic polymerization stabilizers may be present in an amount of about 0.1 part per million or greater based on the weight of the total composition, about 1 part per million by weight or greater or about 5 parts per million by weight or greater. The anionic polymerization stabilizers may be present in an amount of about 1000 parts per million by weight or less based on the weight of the total composition, about 500 parts per million by weight or less or about 100 parts per million by weight or less. [0048] It is desirable that the curable compositions be liquid so as to function well in additive manufacturing. It is desirable that a significant portion of the monomers utilized be liquid. If the monomers are not liquid, then a liquid dispersant of solvent which does not negatively impact additive manufacturing processes may be used. The curable compositions may be prepared by contacting and blending the ingredients using standard techniques. The reactants may be added in one or more stages or steps. The reactants may be substantially anionically or radically inactive before exposure to radiation.

[0049] Disclosed are articles prepared from the disclosed compositions prepared by additive manufacturing techniques. Disclosed are cured articles comprising a plurality of layers wherein each layer comprises a mixture of polymers prepared from compositions disclosed herein wherein the cohesive forces which connect the layers are created or increased by anionic polymerization, Michael addition and/or crosslinks between one or more first compounds comprising one or more 1 ,1 -disubstituted activated alkene compounds.

[0050] The polymerization can proceed at any reasonable temperature including at ambient temperatures, from about 20 to 35 °C. Polymerization can be terminated by contacting the polymeric mixture with an anionic polymerization terminator. Polymerization may be slowed, controlled, or inhibited by an anionic polymerization terminator such that anionic polymerization occurs over a prolonged period of time. The anionic polymerization terminator may be an acid. Exemplary anionic polymerization terminators include, for example, mineral acids such as methane sulfonic acid, sulfuric acid, and phosphoric acid and carboxylic acids such as acetic acid and trifluoroacetic acid.

[0051] The article may be formed by a 3D printing process. The 3D printing process may include steps of thermal polymerization, radical polymerization or anionic polymerization. The 3D printing process may have layers that stack on top of each other. The 3D printing process may include one or more layers, two or more layers, three or more layers, four or more layers, or a plurality of layers that are stacked such that a 3D article is formed therefrom. The 3D printing process may include layers with identical, similar or differing dimensions. The layers may include an adhesive layer between the first layer, second layer or subsequent layers that are the curable composition. The layers may be adhered together by cohesive properties, adhesive properties, covalent properties, polymeric properties, or a combination thereof.

[0052] The articles may be formed with only the curable composition such that a molded or 3D article is formed therefrom. The curable compositions disclosed may be subjected to processes disclosed in the art for additive manufacturing wherein the processes are adapted as disclosed herein. Additive manufacturing is the process of joining materials to make structures from a 3-dimensional model a layer at a time, this process is more commonly referred to a 3D printing. In additive manufacturing a part is built up layer by layer using powders or liquids. The process starts by drawing a three-dimensional computer-aided design model using software, often referred to CAD software. The software used allows the design to be partitioned into layers. Each layer is sent to a device such as a printer to be applied with each subsequent layer being deposited on the previous layer to form the structure. The standard additive manufacturing processes include material extrusion, vat photo polymerization, powder bed fusion, binder jetting, sheet lamination, material jetting and directed energy deposition. The compositions disclosed herein may be used in any of the disclosed processes. Stereo lithography, digital light processing, and continuous liquid interface production processes may be used with the disclosed compositions.

[0053] The additive manufacturing processes involve selecting a discrete layer of the curable composition. The layer is exposed to radiation to initiate cure. Cure may be anionic or anionic and free radical cure. Cure is initiated by exposing the selected discrete layer to radiation sufficient to cause the photolatent bases to form amines to initiate anionic polymerization and, optionally form free radicals to initiate free radical polymerization. It may be desirable to initiate both free radical polymerization and anionic polymerization. Where both types of polymerization are initiated, the free radical cure will continue as long as the layer is exposed to radiation when a free radical photoinitiator and/or the photolatent base generates free radicals during exposure to radiation. Anionic polymerization will continue after the exposure to radiation is discontinued. It is desired that the anionic cure continue after the exposure to radiation is discontinued and continues after the next layer is contacted with the previous layer so that cohesive bonds are formed between the layers. The shape of each layer transverse to the faces of each layer are defined by the model and formed according to the model. The thickness of each layer is determined by the model taking into account the particular process used. Each subsequent layer is applied as specified according to the model.

[0054] The radiation used may be within a wavelength range of from about 200 to 800 nm or 200 nm to about 650 nm and chosen based on the radiation source used and the nature of the photolatent base, photoinitiator and photosensitizers used. In this application radiation of provided by a source of radiation and the use of the term exposed to radiation may be interpreted to mean exposed to a radiation source. The use of photolatent based and/or free radical photoinitiators with infrared sensitizers in contemplated herein. The anionic polymerization can be accelerated by temperature and/or by the amount of the generated base. The latter is governed by the efficiency of the photolatent base, the level of exposure, irradiance and optical transparency of the photopolymer (or amount of UV absorbers/blockers). Since free radical polymerization is much less sensitive to temperature, a sufficient difference in free radical and anionic reactivities can be obtained simply by determining suitable temperature, exposure and irradiance levels in the 3D printing step and the temperature can also be changed for the post-cure step. The radiation sources are well known and include ultraviolet radiation sources such as mercury lamps and visible light sources such as light emitting diodes. After completion of the article the article may be post cured by exposure to elevated temperature although this may not be desirable. The process disclosed herein may render post cure unnecessary. The exposure time and exposure intensity vary depending on the process, the light source and the ingredients.

EMBODIMENTS

[0055] 1. A curable composition comprising a mixture of a) one or more first compounds comprising one or more 1 ,1 -disubstituted activated alkene compounds; b) one or more photolatent bases which when exposed to radiation initiates and forms a base which initiates anionic polymerization of the one or more 1 ,1 -disubstituted activated alkene compounds; and c) one or more acidic compounds which inhibit anionic polymerization of the one or more 1 ,1- disubstituted activated alkene compounds and the one or more acidic compounds are present in an amount sufficient to slow the anionic cure.

[0056] 2. A curable composition according to Embodiment 1 wherein the one or more photolatent bases form one or more bases which initiate anionic polymerization.

[0057] 3. A curable composition according to Embodiment 1 or 2 wherein the one or more photolatent bases form amines comprising one or more amino, amidine or guanidine groups or a carbanion.

[0058] 4. A curable composition according to any one of the preceding embodiments wherein the one or more 1 ,1 -disubstituted activated alkene compounds comprise one or more 1 ,1 -dicarbonyl substituted- 1-alkenes or cyano-acrylates.

[0059] 5. A curable composition according to any one of the preceding embodiments wherein the photolatent base generates free radicals upon exposure to radiation.

[0060] 6. A curable composition according to any one of Embodiments 1 to 4 comprising one or more free radical photoinitiators that upon exposure to radiation generates free radicals which initiate free radical polymerization.

[0061] 7. A curable composition according to any one of the preceding embodiments wherein the photoinitiator is one or more of alpha aminoketones, alpha hydroxyketones, phosphine oxides, phenylglyoxalates, thioxanthones, benzophenones, benzoin ethers, oxime esters, acetophenones, dyes that can be excited by UV and visible parts of the electromagnetic spectrum such as fluorone dyes, cyanine and phthalocyanine dyes, coumarins, peroxides and azo compounds or mixtures thereof.

[0062] 8. A curable composition according to any one of the preceding embodiments wherein the composition comprises one or more second compounds which are free radically polymerizable when exposed to free radicals formed a photoinitiator upon exposure to radiation. [0063] 9.. A curable composition according to any one of the preceding embodiments wherein the one or more second compounds which are free radically polymerizable when exposed to the photoinitiator and radiation comprises one or more (meth)acrylates, conjugated dienes, vinylidene substituted aromatic monomers, vinylidene halides, vinyl acetates, unsaturated nitriles cyanoacrylates, maleates, fumarates, maleimides, and itaconates.

[0064] 10. A curable composition according to any one of the preceding embodiments which comprises one or more photosensitizers which broadens the wavelengths of radiation at which the photolatent base forms bases which initiate anionic polymerization.

[0065] 11. A curable composition according to any one of Embodiments 5 to 9 which comprises a photosensitizer which broadens the range of the wavelengths of radiation at which the photolatent base and free radical photoinitiator initiate polymerization.

[0066] 12. A curable composition according to any one of the preceding embodiments wherein the composition comprises one or more third compounds which are anionically polymerizable.

[0067] 13. A curable composition according to any one of the preceding embodiments wherein the one or more third compounds which are anionically polymerizable comprise one or more isocyanate functional compounds and epoxy functional compounds.

[0068] 14. A curable composition according to any one of the previous embodiments which comprises one or more fourth compounds which are compounds, oligomers or polymers having functional groups which Michael add to unsaturated groups when exposed to amines.

[0069] 15. A curable composition according to any one of the preceding embodiments wherein the one or more 1 , 1 -disubstituted activated alkene compounds comprise one or more 1 ,1 -dicarbonyl substituted- 1 -alkenes.

[0070] 16. A curable composition according to any one of the preceding embodiments wherein the one or more 1 ,1 -disubstituted activated alkene compounds are present in an amount of about 10 percent by weight to about 99 percent by weight based on the weight of the curable composition.

[0071] 17. A curable composition according to any one of the preceding embodiments wherein the one or more one or more second compounds which are free radically polymerizable are present in an amount of about 1 percent by weight to about 90 percent by weight based on the weight of the curable composition.

[0072] 18. A curable composition according to any one of the preceding embodiments wherein the one or more third compounds which are anionically polymerizable are present in an amount of about 1 percent by weight to about 90 percent by weight based on the weight of the curable composition.

[0073] 19. A curable composition according to any one of the preceding embodiments wherein the one or more fourth compounds are present in an amount of about 1 percent by weight to about 90 percent by weight based on the weight of the curable composition.

[0074] 20. A curable composition according to any one of the preceding embodiments wherein the one or more photolatent bases form monoalkyl amines, dialkyl amines, trialkyl amines or amidines when exposed to radiation.

[0075] 21 . A curable composition according to any of the preceding embodiments wherein the one or more photolatent bases are present in an amount of about 0.05 to about 15 percent based on the weight of the composition.

[0076] 22. A curable composition according to any of the preceding embodiments wherein the acidic compounds that slow anionic polymerization comprise one or more of carboxylic acids, sulfonic acids, sulfuric acids, mineral acids and phosphorus oxoacids or esters thereof.

[0077] 23. A curable composition according to any of the preceding embodiments wherein the acidic compounds that slow anionic polymerization comprise one or more of sulfuric acid, alkyl substituted aryl sulfonic acids, alkyl sulfonic acids and fluorinated carboxylic acids or esters thereof.

[0078] 24. A curable composition according to any of the preceding embodiments wherein the acidic compounds that slow anionic polymerization comprise one or more of dodecylbenzenesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, sulfuric acid and trifluoroacetic acid or esters thereof.

[0079] 25. A curable composition according to any of the preceding embodiments wherein the acidic compounds that slow anionic polymerization are present in an amount sufficient to slow down the cure of anionic polymerization.

[0080] 26. A curable composition according to any of the preceding embodiments wherein the one or more 1 ,1 -dicarbonyl-substituted-1-alkenes may be one or more of monofunctional 1 ,1- dicarbonyl-substituted-1 -alkenes, multifunctional 1 ,1-dicarbonyl-substituted-1-alkenes or polyesters of difunctional alcohols and 1 ,1-dicarbonyl-substituted-1-alkenes. [0081] 27. A curable composition according to any of the preceding embodiments comprising one or more free radical polymerization initiators.

[0082] 28. A curable composition according to any of the preceding embodiments wherein the one or more free radical polymerization initiators is one or more peroxide and azo compounds which will accelerate free radical polymerization.

[0083] 29. A curable composition according to any of the preceding embodiments wherein the one or more free radical photoinitiators are present in an amount of about 0.05 to about 20 percent by weight based on the weight of the curable composition.

[0084] 30. A curable composition according to any of the preceding embodiments comprising one or more fillers.

[0085] 31 . A curable composition according to any of the preceding embodiments wherein the one or more fillers are in the form of one or more of particles, fibers, pigments, or hollow spheres. [0086] 32. A two part composition comprising in one part: a) one or more first compounds comprising one or more 1 ,1-disubstituted activated alkene compounds; b) one or more acidic compounds; and in a second part c) one or more weak bases and/or photolatent bases which when exposed to ultraviolet radiation releases one or more amines that initiate anionic polymerization, d) optionally, a free radical initiator that initiates free radical polymerization of the one or more compounds 1 ,1-disubstituted activated alkene compounds; such that when the components are mixed and exposed to radiation the one or more compounds 1 , 1 -disubstituted activated alkene compounds undergo both free radical polymerization and anionic polymerization, wherein the one or more acidic compounds is present in an amount sufficient to slow the anionic cure rate.

[0087] 33. A two part composition according to Embodiment 32 wherein the one or more photolatent bases form one or more bases which initiate anionic polymerization upon exposure to ultraviolet radiation.

[0088] 34. A two part composition according to any one of Embodiments 32 to 33 wherein the one or more photolatent bases form bases comprising an amino, amidine or guanidine group or a carbanion.

[0089] 35. A curable two part composition according to any one of embodiments 32 to 34 wherein the one or more 1 ,1-disubstituted activated alkene compounds comprise one or more 1 ,1 -dicarbonyl substituted- 1-alkenes or cyano-acrylates.

[0090] 36. A two part composition according to any one of embodiments 32 to 35 wherein the composition comprises one or more second compounds which are free radically polymerizable. [0091 ] 37. A two part composition according to any one of embodiments 32 to 36 wherein the one or more second compounds which are free radically polymerizable comprises one or more (meth)acrylates, conjugated dienes, vinylidene substituted aromatic monomers, vinylidene halides, vinyl acetates, cyanoacrylates, maleates, fumarates, maleimides, itaconates and unsaturated nitriles.

[0092] 38. A two part composition according to any one of embodiments 32 to 37 wherein the composition comprises one or more third compounds which are anionically polymerizable.

[0093] 39. A two part composition according to Embodiment 38 wherein the one or more third compounds which are anionically polymerizable comprise one or more isocyanate functional compounds, and epoxy functional compounds.

[0094] 40. A two part composition according to any one embodiments 32 to 39 which comprises one or more fourth compounds which are compounds, oligomers or polymers having functional groups which Michael add to unsaturated groups when exposed to bases.

[0095] 41 . A two part composition according to any one of embodiments 32 to 40 wherein the one or more 1 , 1 -disubstituted activated alkene compounds comprise one or more 1 ,1 -dicarbonyl substituted-1 -alkenes.

[0096] 42. A two part composition according to any one of embodiments 32 to 41 wherein the one or more 1 ,1 -disubstituted activated alkene compounds are present in an amount of about 10 percent by weight to about 99 percent by weight based on the weight of the two part composition. [0097] 43. A two part composition according to any one of embodiments 32 to 42 wherein the one or more one or more second compounds which are free radically polymerizable are present in an amount of about 1 percent by weight to about 90 percent by weight based on the weight of the two part composition.

[0098] 44. A two part composition according to any one of embodiments 32 to 43 wherein the one or more third compounds which are anionically polymerizable are present in an amount of about 1 percent by weight to about 90 percent by weight based on the weight of the two part composition.

[0099] 45. A curable composition according to any one of embodiments 32 to 44 wherein the one or more fourth compounds are present in an amount of about 1 percent by weight to about 90 percent by weight based on the weight of the curable composition.

[00100] 46. A two part composition according to any of embodiments 32 to 45 wherein the one or more photolatent bases are present in an amount of about 0.05 to about 20.0 percent by weight based on the weight of the composition. [00101] 47. A two part composition according to any of embodiments 32 to 46 wherein the acidic compounds that slow anionic polymerization comprise one or more of carboxylic acids, sulfuric acids, sulfonic acids and phosphoric acids.

[00102] 48. A two part composition according to any of the preceding embodiments 32 to 47 wherein the acidic compounds that slow anionic polymerization comprise one or more of sulfuric acids, alkyl substituted aryl sulfonic acids, alkyl sulfonic acids and fluorinated carboxylic acids. [00103] 49. A two part composition according to any of embodiments 32 to 48 wherein the acidic compounds that anionic polymerization comprise one or more of dodecylbenzenesulfonic acid, p-toluenesulfonic acid, methane sulfonic acid, sulfuric acid and trifluoroacetic acid.

[00104] 50. A two part composition according to any of embodiments 32 to 49 wherein the acidic compounds that inhibit anionic polymerization are present in an amount of about 0.0001 to about 1.0 percent based on the weight of the two part composition.

[00105] 51 . A two part composition according to any of embodiments 32 to 50 wherein the one or more 1 ,1-dicarbonyl-substituted-1-alkenes may be one or more of monofunctional 1 ,1- dicarbonyl-substituted-1-alkenes, multifunctional 1 ,1-dicarbonyl-substituted-1-alkenes or polyester of difunctional alcohols and 1 ,1-dicarbonyl-substituted-1-alkenes.

[00106] 52. A two part composition according to any of embodiments 32 to 51 comprising one or more free radical polymerization initiators the one or more free radical comprising one or more peroxide or azo compounds.

[00107] 53. A two part composition according to any of embodiments 32 to 52 wherein the one or more free radical polymerization initiators are present in an amount of about 0.05 to about 20 percent by weight based on the weight of the two part composition.

[00108] 54. A two part composition according to any one of embodiments 32 to 53 embodiments comprising one or more fillers.

[00109] 55. A two part composition according to any one of embodiments 32 to 54 wherein the one or more fillers are in the form of one or more of particles, fibers, pigments, hollow spheres. [00110] 56. A two part composition according to any of embodiments 32 to 55 wherein the one or more fillers are present in the composition in an amount of about 1 to about 50 percent by weight of the two part composition.

[00111] 57. A two part composition according to any one of embodiments 32 to 56 wherein the photolatent base also generates a free radical upon exposure to radiation.

[00112] 58. A two part composition according to any one of Embodiments 32 to 56 comprising a free radical photoinitiator that upon exposure to radiation generates free radicals which initiates free radical polymerization. [00113] 59. A two part composition according to embodiment 58 wherein the photoinitiator is one or more of alpha aminoketones, alpha hydroxyketones, phosphine oxides, phenylglyoxalates, thioxanthones, benzophenones, benzoin ethers, oxime esters, acetophenones, dyes that can be excited by UV and visible parts of the electromagnetic spectrum such as fluorone dyes, cyanine and phthalocyanine dyes, coumarins, peroxides and azo compounds, or mixtures thereof. [00114] 60. A two part composition according to embodiment 58 wherein the photoinitiator is present in an amount of about 0.05 to about 20 percent based on the weight of the two part composition.

[00115] 61. A cured article comprising a plurality of layers wherein each layer comprises a mixture of polymers prepared from a composition according to any one of embodiments 1 to 60 wherein the cohesive forces which connect the layers are connected by anionic polymerization, Michael addition and/or crosslinks between the one or more first compounds comprising one or more 1 , 1 -disubstituted activated alkene compounds.

[00116] 62. A method comprising: i) forming a layer of a composition according to any one of Embodiments 1 to 31 ; ii) exposing the layer to radiation so as to cause the photolatent base to initiate free radical polymerization and to release an amine which upon release initiates anionic polymerization under conditions such that the anionic polymerization proceeds and is slower than where no acid is present; iii) applying in sequence upon each layer another layer of the mixture while the anionic cure of the layer upon which each layer is deposited is still proceeding; iv) exposing each succeeding layer to radiation; wherein succeeding layers are applied until a desired shape is formed.

[00117] 63. A method comprising: i) mixing the two parts of the two part composition according to any one of Embodiments 32 to 60, and forming the mixture into a discrete layer; ii) exposing the discrete layer of the mixture to radiation such that the photolatent base dissociates and initiates anionic cure wherein the rate of anionic polymerization proceeds and is slower than where no acid is present iii) applying in sequence upon each layer another layer of the mixture of the two parts: while the anionic cure of the layer upon which each layer is deposited is still proceeding; iv) exposing each succeeding layer to radiation; wherein succeeding layers are applied until a desired shape is formed. [00118] 64. The method of Embodiment 63 wherein the weak base or photolatent base is applied to the layer that is being printed, optionally by jetting or spraying.

EXAMPLES

[00119] The following examples are provided to illustrate the disclosed materials but are not intended to limit the scope thereof. All parts and percentages are by weight unless otherwise indicated.

[00120] Materials and Methods

[00121] Materials -Methylene malonate monomers including dihexyl methylene malonate (DHMM), dicyclohexyl methylene malonate (DCHMM), and methylene malonate oligomer based on 1 ,4-butanediol (BD-PES) are available from Sirrus, Inc. 1 ,4-butanediol diacrylate (BDDA), 1 ,4- butanediol-dimethacrylate (BDDMA), 1 ,6-hexanediol diacrylate (HDDA), isobornyl acrylate (IBOA), and isobornyl methacrylate (IBOMA) are obtained from Arkema. Radical photoinitiators 1-hydroxycyclohexyl phenyl ketone and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) are supplied by MilliporeSigma and Rahn AG, respectively. Photolatent base NVOC-DEA is 6- nitroveratryl chloroformate coupled with diethylamine. Ethyl 1-methyl-3-piperidinecarboxylate (EMPC) and methanesulfonic acid (MSA) were obtained from MilliporeSigma. BD-PES is 1 , 1 -disubstituted activated alkene polymer corresponding to the following formula wherein n is an integer from 1 to 6.

[00122] Photopolymerization Techniques

Curing profiles are measured by FT-IR during photopolymerization. These samples are cast between glass microscope slides with a rubber spacer and irradiated with a mercury arc lamp spot cure system from Synchron, Inc. The irradiance at the sample is 20 mW/cm2 UVA. Free standing films are prepared by casting liquid photopolymer resin between glass plates with plastic spacers and clamping them together. They are then passed through a Heraeus Noblelight LC6B UV curing conveyor with a Fusion D bulb at a speed of 5 ft/min. Each pass provided 6.7 J/cm2 UVA energy to the sample.

[00123] FT-IR

A Perkin-Elmer Spectrum One Fourier-transform infrared spectrometer is used to measure the conversion of carbon-carbon double bonds. For time-resolved measurements the alkene conversion is calculated as the disappearance of the near-IR peak found at 6190 cm-1 in the transmission spectra of the samples. For cured polymer films, the alkene conversion is measured by attenuated total reflectance (ATR) as the fractional decrease in the area of the mid-IR peak occurring at 804 cm-1 . These mid-IR spectra are normalized by the area of the carbonyl peak at 1720 cm-1.

[00124] DSC

Heat-cool-heat experiments are performed on a TA Instruments DSC 250. Heating and cooling cycles are run at 5 °C/min with a maximum temperature of 200 °C. The glass transition temperature of samples is calculated from the second heating cycle by the half-height midpoint method.

[00125] DMA

Dynamic mechanical analyses are performed to measure tensile properties of prepared polymer films. Tests are performed on a TA instruments Q800 DMA. Multi-frequency multi-strain tests are run at 1 Hz with 0.1% strain from -60 °C to 250 °C at a heating rate of 5 °C/min. Two heating cycles are recorded for each sample. Glass transition temperatures are recorded as the temperature at which the tan delta peak reached its maximum value. Strain ramp tests are performed at room temperature with a strain rate of 2 %/min.

[00126] Example 1 is a cure of methylene malonate with a photolatent base.

A 1 ,1 -disubstituted activated alkene compound is mixed with 2 wt% of NVOC-DEA. This mixture is stable (sample is still liquid with no noticeable increase in viscosity) for at least 14 days. This mixture is then cast between glass plates for a film thickness of 125 microns. The sample is then passed under a Fusion D bulb on a Heraeus Noblelight LC6B UV curing conveyor 6 times at a speed of 5 ft/min, with each pass providing a maximum irradiance of 1 .0 W/cm ² UVA and a dose of 6.7 J/cm ² . The alkene bonds are 38% consumed, and a slightly tacky, free-standing film is produced. Alkene conversion is measured as the decrease in the area of the FT-IR peak occurring at 804 cnr ¹ after the spectrum is normalized to a reference peak at 1720 cm ^-1 . After irradiation, the sample remains at room temperature in the dark for 24 hours. The alkene conversion after 24 hours is 67%. These results indicate that the photogenerated amine persists after the UV exposure and continues to initiate polymerization of methylene malonates in the dark. Table 1 shows the cure time, glass transition temperature, and storage modulus of Example 1 .

[00127] Example 2 [00128] A shelf life test is performed to see what amount of acid is needed to stabilize the 1 ,1- disubstituted activated alkene when mixed with different loadings of a photolatent base, and the results are included in Table 2. Table 2 shows the stability of the polyester with the photolatent base.

[00129] Example 3

[00130] Diethyl methylene malonate is mixed with 0.5 wt% of a photolatent base CG 277 and is irradiated for 5 minutes. Less than 10% alkene conversion occurred during this time. With the light off, anionic polymerization starts after about an hour and 100% conversion is reached after about 100 minutes. In comparison, when this same formulation is mixed but not exposed to any irradiation, 100% conversion is reached after 150 minutes. The photolatent base is a weak base and will eventually cause polymerization if there is not enough acid stabilizer in the system. [00131] Example 4

Anionic post-cure of methylene malonate is shown through the addition of a relatively weak base prior to UV exposure. This allows for the photoinduced free-radical cure to take place before significant anionic cure has occurred. To illustrate this effect BD-PES and blends of acrylates are prepared with and without the addition of a weak base, ethyl 1-methyl-3-piperidinecarboxylate (EMPC). EMPC is added 5 minutes before UV exposure. TPO photoinitiator is used for the free- radical UV cure. The concentration of TPO is varied for each sample until a double bond conversion of 40-63% is achieved after the UV step. This assures the samples have sufficient level of unreacted methylene malonate groups available for anionic post-cure. The double bond conversion of these films is measured immediately after UV irradiation and then again 24 hours later. Table 3 shows the latent cure of the polyester with a pre-mixed weak base. 50% Acrylate 1

00132] Unreacted methylene malonate groups and presence of anionic inil iator are required for post-cure of alkenes as shown in Table 3.

[00133] Example 5

The 3D printing working time between mixing of two part composition and gelation of mixture, which is measured as the time at which the resin no longer flowed under its own weight, is measured for a 1 , 1 -disubstituted activated alkene for a variety of base loadings. Each mixture includes 50 ppm methanesulfonic acid and 2000 ppm TPO photoinitiator. Under these conditions, a printing time of greater than 4 hours can be achieved.

Table 4 shows the gelation time in minutes of the two part composition.

[00134] When the resin is UV-cured, the subsequent anionic polymerization may be slowed, but it still proceeds. For the case above with 125 ppm EMPC, the un-irradiated resin has a pot life of 127 minutes. In contrast, the irradiated film begins to post-cure at about 140 minutes and nearly completes the post-cure at 350 minutes.

[00135] Example 6

A 500-micron film of a 1 ,1 -disubstituted activated alkene is UV cured using 0.2 wt% TPO photoinitiator by irradiating with 6 J/cm ² UVA light. Weak base (EMPC) is added at an amount of 0.01 wt% before UV curing to slowly initiate anionic polymerization. The Young’s Modulus is 0.036 MPa immediately after UV cure, which increases to 2.02 MPa after 24 hours of post-cure time. To show bonding between layers, a strip of this film is cut and overlaid immediately after UV curing. The overlaid area is 25% of the total area between clamps. From a tensile strain-to-break test, this overlay sample has a modulus of 1.76 MPa and broke across one of the strips rather than breaking across the area of contact between the strips showing excellent bonding between the two overlay pieces.

[00136] Example 7

Films of UV cured multifunctional methylene malonate and its blends with monofunctional methylene malonates are compared against the cured films of 1 ,4-butanediol diacrylate. These films are prepared by dissolving 2 wt% 1-hydroxycyclohexyl phenyl ketone photoinitiator in the monomer composition. The compositions are then cast at a thickness of 500 microns and passed through the UV conveyor 4 times. The cured films are characterized for double bond conversion, Tg, and storage modulus. The results can be found in Table 5. The double bond conversion for the BD-PES sample is similar to the BDDA sample despite the BD-PES sample having an average functionality more than 3 compared to an average functionality of 2 for BDDA. The Tg is 11 °C higher by DMA for BDDA over BD-PES. Diluting BD-PES with methylene malonate monomers increased the extent of the double bond conversion in the cured film. Adding 20 wt% of a high-Tg monomer, DCHMM, increased the film Tg by 26 °C, and adding 20 wt% of a low Tg monomer, DHMM, decreased the film Tg by 10 °C. The storage modulus is higher for BD-PES than for BDDA. The results are compiled in Table 5.

Table 5: Thermal Properties of UV Cured Methylene Malonates and BDDA.

[00137] Parts by weight as used herein refers to 100 parts by weight of the composition specifically referred to. Any numerical values recited in the above application include all values from the lower value to the upper value in increments of one unit provided that there is a separation of at least 2 units between any lower value and any higher value. As an example, if it is stated that the amount of a component or a value of a process variable such as, for example, temperature, pressure, time and the like is, for example, from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, it is intended that values such as 15 to 85, 22 to 68, 43 to 51 , 30 to 32 etc. are expressly enumerated in this specification. For values which are less than one, one unit is considered to be 0.0001 , 0.001 , 0.01 or 0.1 as appropriate. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value, and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner. Unless otherwise stated, all ranges include both endpoints and all numbers between the endpoints. The term “consisting essentially of” to describe a combination shall include the elements, ingredients, components or steps identified, and such other elements ingredients, components or steps that do not materially affect the basic and novel characteristics of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, ingredients, components or steps herein also contemplates embodiments that consist essentially of the elements, ingredients, components or steps. Plural elements, ingredients, components or steps can be provided by a single integrated element, ingredient, component or step. Alternatively, a single integrated element, ingredient, component or step might be divided into separate plural elements, ingredients, components or steps. The disclosure of “a” or “one” to describe an element, ingredient, component or step is not intended to foreclose additional elements, ingredients, components or steps.