COMPOSITIONS

FIELD

[0001] The present invention relates to two-part polyacrylate compositions, which may be cured at room temperature. The two-component curable polyacrylate composition comprises at least one polyacrylate polymer in at least one of the parts; at least one (meth)acrylate monomer in at least one of the parts; at least one filler in at least one of the parts; an oxidizing agent in one part and a reducing agent in a part that does not include the oxidizing agent. Cured reaction products of these compositions are resistant to coolant and oil and are useful, for example, as gaskets, sealants, potting materials, and adhesive materials.

[0002] The present invention also relates to methods of making cured polyacrylate compositions by reacting the first part and second part at room temperature to form the cured polyacrylate composition.

BRIEF DESCRIPTION OF RELATED TECHNOLOGY

[0003] Cured polyacrylate compositions have excellent sealing and adhesive properties, and have many commercial uses they can be formed into gaskets which are used extensively in the automotive industry (e.g., in internal combustion engines) or applied as conformal coatings in electronics applications. Polyacrylate compositions have been used for mold-in-place and cured-in-place gasket applications. Polyacrylate materials are typically light curable and/or moisture curable. Light curable materials will not cure if light cannot reach the material. Moisture cure material have the disadvantage of moisture dependence, which leads to slow curing and low depth of cure if moisture is not accessible. Accordingly, it would be desirable to have two-component polyacrylate compositions that do not rely on radiation or moisture to initiate curing. SUMMARY

[0004] The present invention relates to two component polyacrylate compositions, which may be cured at room temperature to produce cured polyacrylate materials. The present invention also relates to methods of making cured polyacrylate materials by reacting the first part and second part at room temperature to form the cured

polyacrylate composition.

[0005] The two-component curable polyacrylate composition comprises at least one polyacrylate polymer in at least one of the parts; at least one (meth)acrylate monomer in at least one of the parts; at least one filler in at least one of the parts; an oxidizing agent in one part and a reducing agent in a part that does not include the oxidizing agent.

[0006] In one aspect of the present invention, there is provided a two-component, room temperature curable polyacrylate composition which includes:

A. a first part including:

an oxidizing agent including an optional carrier;

optionally a polyacrylate polymer,

optionally a (meth)acylate monomer, and

optionally a filler, and

B. a second part including:

a reducing agent including an optional carrier,

optionally a polyacrylate polymer,

optionally a (meth)acylate monomer,

optionally a filler,

wherein at least one of the first part or the second part comprises a polyacrylate polymer, an (meth)acylate monomer and a filler.

[0007] In another aspect of the present invention, there is provided a two-part, room temperature curable polyacrylate composition which includes:

A. a first part including:

i. about 45% to about 65% by weight of a first polyacrylate polymer. ii. about 20% to about 30% by weight of a first (meth)acylate monomer,

iii. about 5% to about 50% by weight of a first filler, and iv. about 0.5% to about 5% by weight of an oxidizing agent including an optional carrier; and

B. a second part including:

i. about 45% to about 65% by weight of a second polyacrylate polymer.

ii. about 20% to about 30% by weight of a second (meth)acylate monomer,

iii. about 5% to about 50% by weight of a second filler, and iv. about 0.2% to about 2% by weight of a reducing agent including an optional carrier;

wherein the ratio of the first part to the second part is about 1 :1.

[0008] In some embodiments either or both of the first and second parts can comprise a photoinitiator. These embodiments have a dual cure (redox and radiation) mechanism.

[0009] In still another aspect of the present invention, there is provided a process of making a cured polyacrylate composition which includes the steps of:

providing an polyacrylate composition which includes:

A. a first part including:

an oxidizing agent including an optional carrier;

optionally a polyacrylate polymer,

optionally a first (meth)acylate monomer, and

optionally a first filler, and

B. a second part including:

a reducing agent including an optional carrier, optionally a polyacrylate polymer,

optionally a (meth)acylate monomer,

optionally a filler, wherein at least one of the first part or the second part comprises a polyacrylate polymer, an (meth)acylate monomer and a filler; and mixing the first part and the second part to initiate a reaction and produce a cured polyacrylate material.

[0010] In yet another aspect of the present invention, there is provided cured reaction products of the two component polyacrylate composition disclosed herein.

[0011] In another aspect of the invention there is provided a process for making an assembly which includes the steps of:

a) providing a first substrate and a second substrate;

b) providing part A and part B of the two component polyacrylate composition disclosed herein;

c) mixing part A and part B;

d) disposing the mixed polyacrylate composition between the first substrate and the second substrate panel; and

e) curing the polyacrylate composition to bond the first substrate to the second substrate.

DETAILED DESCRIPTION

[0012] The terms "(meth)acrylate" or "(meth)acryloxy" will include methacrylate and acrylate and methacryloxy and acryloxy, respectively.

[0013] The term "telechelic polymer" is a di-end-functional polymer where both ends possess the same functionality.

[0014] The term "cure" or "curing," refers to a change in state, condition, and/or structure in the mixed composition induced by mixing the separate components of that composition. The terms include at least partial crosslinking, and in more desirable embodiments substantial or full crosslinking. [0015] In one aspect of the present invention, there is provided a curable, two component polyacrylate composition. As used herein a two-component (2K)

composition has two or more components. Each of the components is stored

separately from the other components. The components are mixed immediately prior to use. Mixing of the components starts a cure reaction so storage after mixing is not possible.

[0016] The first part includes an oxidizing agent and the second part includes a reducing agent. At least one of the first part or the second part comprises a polyacrylate polymer, at least one of the first part or the second part comprises a (meth)acylate monomer and at least one of the first part or the second part comprises a filler. In some embodiments either or both of the first part and the second part comprise multiple, independently chosen, polyacrylate polymers, (meth)acylate monomers and/or fillers. In some embodiments both of the first part and the second part can comprise some or all of a polyacrylate polymer, an (meth)acylate monomer and a filler. The polyacrylate polymer, (meth)acylate monomer and filler used in one part can be different from the polyacrylate polymer, (meth)acylate monomer and filler used in the other part.

[0017] Mixing the first part and the second part initiates a redox reaction of the oxidizing agent and the reducing agent leading to curing of the mixed composition. The redox reaction and curing can take place at room temperature and does not require heat, irradiation or moisture. The disclosed compositions will not cure by exposure to anaerobic conditions or heat. The disclosed composition will only cure by exposure to radiation if the composition optionally includes a photoinitiator. In some variations the disclosed composition will not cure by exposure to radiation.

[0018] In one embodiment the backbone of the polyacrylate polymers are formed from various monofunctional (meth)acrylate monomers, such as homopolymers of

monofunctional C1-10 alkyl(meth)acrylates and copolymers of monofunctional C1-10 alkyl(meth)acrylates. Among the particularly useful monomers used include ethyl acrylate, methoxyethyl acrylate, n-butyl acrylate and homopolymers and copolymers thereof. As additional examples of useful monomers, there are included (meth)acrylic monomers such as (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n- propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl

(meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl

(meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl

(meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate), phenyl (meth)acrylate, tolyl (meth)acrylate, benzyl

(meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2- hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, stearyl (meth)acrylate, glydicyl (meth)acrylate, 2-aminoethyl (meth)acrylate, gamma-(methacryloxoxypropyl) trimethoxysilane, (meth)acrylic acid-ethylene oxide adduct, trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl

(meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, 2-perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl

(meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, 2-perfluorohexadecylethyl

(meth)acrylate, etc.; styrenic monomers such as styrene, vinlytoluene, alpha- methylstyrene, chlorostyrene, styrenesulfonic acid and its salt; fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, vinylidene fluoride, etc.; silicon-containing vinyl monomers such as vinyltrimethoxysilane, vinyltriethoxysilane, etc.; maleic anhydride, maleic acid, monoalkyl esters and dialkyl esters of maleic acid; fumaric acid and monoalkyl esters and dialkyl esters of fumaric acid; maleimide monomers such as maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecyclmaleimide, stearylmaleimide phenylmaleimide, cyclohexylmaleimide, etc.; nitrile-containing vinyl monomers such as acrylonitrile, methacrylonitrile, etc.; amide-containing vinyl monomers such as acrylamide, methacrylamide, etc.; vinyl esters such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, vinyl cinnamate, etc.; alkenes such as ethylene, propylene, etc.; conjugated dienes such as butadiene, isoprene, etc.; vinyl chloride, vinylidene chloride, allyl chloride and allyl alcohol. These monomers may be used singly or a plurality of them may be copolymerized. Among these, from the standpoint of physical properties of the product, styrenic monomers and (meth)acrylic monomers are preferred. Desirable are acrylic ester monomers and methacrylic ester monomers.

[0019] Additionally, the backbone of the polyacrylate polymers may be formed from or include one or segments or units of polyurethane, styrene, polyolefin, acrylamide, nylon, (meth)acrylonitrile and/or substituted (meth)acrylonitrile.

[0020] The number average molecular weight of the polyacrylate polymers may be 5,000 to 1 ,000,000, more desirably 10,000 to 100,000. The polyacrylate polymers may also have a polydispersity from about 1.01 to about 2. "Polydispersity" (also known as "polydispersity index" and "molecular weight distribution") refers to the ratio of weight average molecular weight/number average molecular weight for a subject polymer. This value provides an indication of the broadness of the molecular weight distribution of the subject polymer. Thus, for a monodisperse polymer where the weight average molecular weight equals the number average molecular weight, the value will be 1. As the breadth of molecular weight distribution increases, the polydispersity will be greater than 1.

[0021] The polyacrylate polymers can be prepared using standard techniques known in the art, or obtained from suitable commercial sources. Preparation techniques include controlled radical polymerization processes, including Single Electron Transfer Living Radical Polymerization (SET-LRP), by stable free radical polymerization (SFRP) such as reversible deactivation by coupling, or by degenerative transfer (DT). Once the polymerization is complete, the method may include further reacting the resultant polymer to form functional end groups onto the polymer. Forming functional ends on the polymer may be done, for example, by performing either an end-capping reaction or a substitution reaction.

[0022] To functionalize the polymeric final product by an end-capping reaction, the required steps may be done in situ in the reaction vessel at the end of the initial reaction, prior to work-up. To perform an end-capping functionalization of at least one polymer end, the steps include: providing a final polymer product; adding a capping agent to the vessel; quenching the reaction; and purifying the polyacrylate polymer.

The capping agent may include one or a combination of compounds, as may be desired to cap the end group of the final polyacrylate polymers with a desired functional end group while maintaining chain stability and integrity.

[0023] The final polyacrylate polymer can include, for example, homopolymers and/or (co)polymers of the above monomers, which may be block, random, statistical periodic, gradient star, graft, comb, (hyper)branched or dendritic polymers. The "(co)"

parenthetical prefix in conventional terminology is an alternative, viz., "(co)polymer means a copolymer or polymer, including homopolymer. Similarly, "(hyper)" as used herein, refers to a comparatively high degree of dendritic-like branching along the co- polymer backbone as compared to a low degree of branching.

[0024] U.S. Patent Numbers 6,720,395; 7,781 ,494, 9,006,363; 9,371 ,474 and

9,371 ,474, the contents of each of which are incorporated by reference herein, describe some useful polyacrylate polymers and methods of making those polymers.

[0025] In one embodiment the polyacrylate polymer has the structure:

wherein each A is an independently chosen diradical linking group. The diradical linking group can be hydrocarbyl, substituted hydrocarbyl, predominately hydrocarbyl or substituted predominately hydrocarbyl. Each B is an independently chosen diradical linking group. The diradical linking group can be hydrocarbyl, substituted hydrocarbyl, predominately hydrocarbyl or substituted predominately hydrocarbyl. Each R ¹ is independently chosen from H or CH3. Each R ² is independently chosen from C1 to C6 alkyl, preferably C2 to C4 alkyl. Each R ³ is an independently chosen H or CH3. m is an integer from 0 to 10,000, preferably from 50 to 10,000. n is an integer from 0 to 10,000, preferably from 50 to 10,000. p is 0 or 1.

[0026] The term "hydrocarbyl" is intended to refer to moieties which are composed of only carbon and hydrogen atoms. Thus, the term encompasses aliphatic groups such as alkyl, alkenyl, and alkynyl groups; aromatic groups such as phenyl; and alicyclic groups, such as cycloalkyl and cycloalkenyl. The term“predominately hydrocarbyl” refers to moieties that are composed of at least 50 wt.%, preferably 70 wt.%, and up to 90 wt.% carbon and hydrogen atoms with the remainder of the moiety comprised of non-carbon atoms such as heteroatoms.

[0027] The term substituted means substituted by at least one below described substituent group in any possible position or positions. Substituent groups useful in the polyacrylate polymers are those groups that do not significantly diminish the activity of the disclosed compound. Some useful substituent groups include, for example, ester moiety. Unless otherwise specifically limited, a substituent group may be in any possible position or any possible positions if multiply substituted.

[0028] Some commercially available polyacrylate polymers include, for example, as Hytemps acrylate rubbers (acrylic homopolymer and copolymer rubbers available from Nippon Zeon, KK), Toacron AR-601 acrylate rubbers (polyethylacrylate polymers, available from Toa Paint, KK), and RC100C, RC200C, MM110C and RC300C polyacrylate polymers available from Kaneka Corporation.

[0029] In embodiments of the present invention a polyacrylate polymer may be present in the polyacrylate composition in amounts of about 20% to about 80% by weight of the first part, desirably in amounts of about 30% to about 65% by weight of the first part. In embodiments of the present invention a polyacrylate polymer may be present in the polyacrylate composition in amounts of about 20% to about 80% by weight of the second part, desirably in amounts of about 30% to about 65% by weight of the second part. Either or both of the composition parts can optionally comprise multiple polyacrylate polymers which are different from each other.

[0030] The composition can optionally comprise one or more (meth)acrylate monomers. In compositions comprising plasticizers no (meth)acrylate monomer may be included. Preferably, at least one component of the compositions comprises one or more independently selected (meth)acrylate monomers. In some embodiments both components of the polyacrylate composition comprise an independently selected (meth)acrylate monomer. As used herein the term (meth)acrylate is intended to mean, but is not limited to, corresponding derivatives of both acrylic acids and methacrylic acids. Thus, a (meth)acrylate includes both acrylates and methacrylates. Generally, the (meth)acrylate monomer is not particularly restricted and any (meth)acrylate monomer may be employed. Examples of useful (meth)acrylate monomers include, but are not limited to, (meth)acrylic monomers such as (meth)acrylic acid, methyl

(meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl

(meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl

(meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, phenyl (meth)acrylate, tolyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3- methoxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl

(meth)acrylate, stearyl (meth)acrylate, glycidyl (meth)acrylate, 2-aminoethyl

(meth)acrylate, . gamma. -(methacryloyloxypropyl)trimethoxysilane, (meth)acrylic acid- ethylene oxide adduct, trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2- perfluorobutylethyl (meth)acrylate, 2-perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2- perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2- perfluorodecylethyl (meth)acrylate, 2-perfluorohexadecylethyl (meth)acrylate, and the like. [0031] The composition can comprise 10% to 90% (meth)acrylate monomer by weight, preferably 20% to 80% (meth)acrylate monomer by weight. In embodiments of the present invention, a (meth)acrylate monomer may be present in the polyacrylate composition in amounts of about 10% to about 40% by weight of the first part, desirably in amounts of about 20% to about 30% by weight of the first part. In embodiments of the present invention, a (meth)acrylate monomer may be present in the polyacrylate composition in amounts of about 10% to about 40% by weight of the second part, desirably in amounts of about 20% to about 30% by weight of the second part. Either or both of the composition parts can optionally comprise multiple (meth)acrylate monomers which are different from each other.

[0032] The composition can comprise 5% to 90% filler by weight, preferably 10% to 70% filler by weight. In some embodiments both components of the polyacrylate composition comprise an independently selected filler. In embodiments of the present invention, a filler may be present in the polyacrylate composition in amounts of about 5% to about 50% by weight of the first part, desirably in amounts of about 15% to about 30% by weight of the first part. In embodiments of the present invention, a filler may be present in the polyacrylate composition in amounts of about 5% to about 50% by weight of the second part, desirably in amounts of about 15% to about 30% by weight of the second part. Either or both of the composition parts can optionally comprise multiple fillers which are different from each other.

[0033] Generally, the filler used in the polyacrylate composition is not particularly restricted and any filler known to be compatible with polyacrylate compositions may be employed. Suitable examples of fillers include, but are not limited to, CaC03,

precipitated calcium carbonate, S1O2, fumed silica, BaS04, AI2O3, CaSi0 ₄ ,

ferroaluminum silicate and organic fillers such as polyethylene and polypropylene.

[0034] One component of the polyacrylate composition comprises an oxidizing agent. Generally, the oxidizing agent is not particularly restricted and any oxidizing agent is believed to work to some degree. Suitable examples of oxidizing agents include, but are not limited to, cumene hydroperoxide (CHP), benzoyl peroxide, methyl ethyl ketone peroxides, di-t-butyl peroxide, di-t-amyl peroxide, dicumyl peroxide, diacyl peroxide, decanoyl peroxide, lauroyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butyl perbenzoate, 2,5-bis(t-butylperoxy) 2,5-dimethylhexane, peroxydicarbonates, peroxyesters, dialkyl peroxides, hydroperoxide, peroxyketals, 4,4'-azobis(4-cyanovaleric acid), 1 ,1'- azobis(cyclohexanecarbonitrile), 2,2'-azobisisobutyronitrile ("AIBN"), and mixtures thereof. In one embodiment, the oxidizing agent is cumene hydroperoxide (CHP).

Typically, the oxidizing agent is dissolved or dispersed in a carrier for ease of processing. Carriers are known in the art and some typical carriers include

(meth)acrylate monomers and liquid plasticizers. In embodiments of the present invention, the oxidizing agent may be present in the polyacrylate composition in amounts of about 1% to about 5% by weight of that component, desirably in amounts of about 2% to about 4% by weight of that component. These amounts are weight of oxidizing agent alone with no carrier.

[0035] One component of the polyacrylate composition comprises a reducing agent.

The component comprising the reducing agent will not include the above described oxidizing agent. Generally, the reducing agent is not particularly restricted and any reducing agent is believed to work to some degree. In an embodiment of the present invention, the reducing agent is a thiourea derivative, such as acetyl thiourea, thiourea derivative methyl thiourea, ethyl thiourea , allyl thiourea thiourea, butyl thiourea, hexyl thiourea, octyl thiourea, benzyl thiourea, 1 ,1 ,3-trimethyl thiourea, 1 ,1-diallyl thiourea, 1 ,3-diallyl thiourea, 1-(2-pyridyl)-2-thiourea, acetyl thiourea, propanoyl thiourea, butanoyl thiourea, pentanoyl thiourea, hexanoyl thiourea, heptanoyl thiourea, octanoyl thiourea, nonanoyl thiourea, decanoyl thiourea, benzoyl thiourea or a mixture thereof. Typically, the reducing agent is dissolved or dispersed in a carrier for ease of

processing. Carriers are known in the art and some typical carriers include

(meth)acrylate monomers and liquid plasticizers. In embodiments of the present invention, the reducing agent may be present in the polyacrylate composition in amounts of about 0.05% to about 3% by weight of that component, desirably in amounts of about 0.3% to about 1 % by weight of that component. These amounts are weight of oxidizing agent alone with no carrier.

[0036] In embodiments of the present invention, a photoinitiator may be present in the first and/or the second part of the polyacrylate compositions. Photoinitiators useful in the present invention may be selected from any known free radical type photoinitiator effective for promoting crosslinking reactions. For example, suitable photoinitiators include UV initiators such as benzophenone and substituted benzophenones, acetophenone and substituted acetophenones, benzoin and its alkylesters, xanthone and substituted xanthones. Desirable photoinitiators include diethoxyacetophenone (DEAP), benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether,

diethoxyxanthone, chloro-thioxanthone, azo-bisisobutyronitrile, N-methyl

diethanolaminebenzophenone, and combinations thereof. Visible light photoinitiators include camphoquinone peroxyester initiators, non-fluorene carboxylic acid peroxyester initiators and alkyl thioxanthones, such as isopropyl thioxanthone and combinations thereof.

[0037] If present in both parts, the photoinitiator in the first part and the photoinitiator in the second part of the polyacrylate compositions may be the same or different. In embodiments of the present invention, a photoinitiator may be present in the

polyacrylate composition in an amount of about 2% or less by weight of the part(s) in which the photoinitiator is present, preferably in an amount of about 1% or less by weight.

[0038] In embodiments of the present invention, a stabilizer may be present in the first and/or the second part of the polyacrylate compositions. Stabilizers useful in the present invention may be selected from any known stabilizer for polymer compositions. For example, suitable stabilizers include free-radical stabilizers, anionic stabilizers and stabilizer packages that include combinations thereof. Commonly used free-radical stabilizers include hydroquinone and butylated hydroxytoluene (BHT), while commonly used anionic stabilizers include boron triflouride, boron trifluoride-etherate, sulphur trioxide (and hydrolysis products thereof) and methane sulfonic acid.

[0039] If present in both parts, the stabilizer in the first part and the stabilizer in the second part of the polyacrylate compositions may be the same or different. In

embodiments of the present invention, a stabilizer may be present in the polyacrylate composition in an amount of about 2% or less by weight of the part(s) in which the antioxidant is present, preferably in an amount of about 1% or less by weight.

[0040] In embodiments of the present invention, an antioxidant may be present in the first and/or the second part of the polyacrylate compositions. Antioxidants useful in the present invention may be selected from any known antioxidant. For example, suitable antioxidants include thioesters, phosphates, hindered phenols, pentaerythritol tetrakis(3- (3,5-di-tert-butyl-4-hydroxyphenyl)propionate), tetrakis(methylene 3-(3',5'-di-t-butyl-4 hydroxyphenyl)pro-pionate)methane, 2,2'-ethyldenebis(4,6-di-tertiarybutylphenol), 1 ,1-3- tris(2-methyl-4-hydroxy-5-t-butylephenyl) butane, 1 ,3,5-trimethyl2,4,6,tris(3,5-tertbutyl-4- hydroxybenzyl)benzene, dilaurylthiodipropionate, pentaerythritol tetrakis(beta- laurylthiopropionate), alkyl-aryldi- and polyphosphates, thiophosphites, and

combinations or derivatives thereof.

[0041] If present in both parts, the antioxidant in the first part and the antioxidant in the second part of the polyacrylate compositions may be the same or different. In

embodiments of the present invention, an antioxidant may be present in the polyacrylate composition in an amount of about 2% or less by weight of the part(s) in which the antioxidant is present, preferably in an amount of about 1% or less by weight.

[0042] The two part polyacrylate compositions are preferably free of solvent, although solvent can be added to one or both parts if desired. As used herein solvent free means the composition contains less that 1 wt.% solvent and preferably less than 0.1 wt.% solvent by weight of composition. [0043] The first part and the second part may be used in any one of a plurality of ratios of the first part to second part. Useful ratios range from about 1 :10 to about 10:1 , desirably about 1 :5 to about 5:1. The two components are preferably used in a ratio of about 1 :1 to simplify dispensing of the components and mixing.

[0044] Once mixed, the compositions of the present invention provide relatively fast curing (about 2 minutes to about 60 minutes, preferably about 5 to about 20 minutes) at room temperature.

[0045] The hardness of the cured polyacrylate compositions can be tailored for particular applications and for desired properties. Generally hardness may range from a Shore hardness scale A of about 10 to about 60, preferably about 20 to about 50.

[0046] The tensile strength of the cured polyacrylate compositions generally ranges from about 0.5 to about 9 N/mm2, preferably about 1 to about 3 N/mm2.

[0047] The tensile elongation of the cured polyacrylate compositions generally ranges from about 50% to about 500%, preferably about 100% to about 300%.

[0048] Embodiments of the present disclosure further include components having substrates sealed and/or adhered together by cured reaction products of the disclosed polyacrylate compositions. Components to be sealed by the disclosed curable compositions have a first predetermined sealing surface that is aligned with a second predetermined sealing surface. Typically, the aligned sealing surfaces are in a fixed relationship and move very little relative to each other. The aligned sealing surfaces are generally in fluid communication with a chamber. The seal formed between the aligned sealing surfaces prevents movement of materials between the surfaces and into, or out of, the chamber. One or both of the sealing surfaces can be machined or formed. The predetermined sealing surfaces are designed to allow a curable composition to be disposed on one or both surfaces during initial assembly of the component to form a seal therebetween. Design of the predetermined sealing surfaces enhances parameters such as alignment of the surfaces, contact area of the surfaces, surface finish of the surfaces,“fit” of the surfaces and separation of the surfaces to achieve a predetermined sealing effect. A predetermined sealing surface does not encompass surfaces that were not identified or designed prior to initial assembly to accommodate a seal or gasket, for example the outside surface of a component over which a repair material is molded or applied to lessen leaking Sealing surfaces on an engine block and oil pan or engine intake manifold are examples of sealing surfaces in fixed relationship.

[0049] The disclosed curable compositions immediately after mixing are typically in a flowable state for disposition onto at least a portion of one sealing surface to form a seal between the surfaces when they are aligned. The curable composition can be applied as a film over the sealing surface. The curable composition can also be applied as a bead in precise patterns by tracing, screen printing, robotic application and the like. In bead applications the mixed compositions can be dispensed as a liquid or semi-solid under pressure through a nozzle and onto the component sealing surface. The nozzle size is chosen to provide a line or bead of composition having a desired width, height, shape and volume.

[0050] The disclosed curable compositions have good resistance to many hydrocarbon lubricants. Thus the disclosed curable compositions are advantageous for use in some applications involving sealing vehicle powertrain components to prevent hydrocarbon lubricant leakage. Such applications include, for example, sealing an engine oil pan to an engine block; sealing an engine front cover to an engine block; sealing an engine timing chain cover to an engine block; sealing an engine rear cover to an engine block; sealing a valve cover to a head; sealing transmission components such as a

transmission housing, a transmission cover or a transmission pan; sealing differential components such as a differential cover; sealing transfer case components such as a transfer case housing or a transfer case cover; etc. [0051] The disclosed curable compositions can be useful to seal aqueous based fluids. Thus, the disclosed curable compositions can be advantageous for use in applications involving, for example, sealing of vehicle water pumps; thermostat housings; radiators; etc.

[0052] The disclosed curable compositions would also be advantageous for uses in different applications such as off road vehicles, marine vehicles, aviation vehicles, construction equipment, heavy equipment and industrial equipment.

[0053] The disclosed curable compositions can be used as a formed in place gasket (FIPG). In this application the composition is dispensed onto a first predetermined sealing surface. The first predetermined sealing surface and dispensed composition is aligned and sealingly engaged with a second predetermined sealing surface before the composition has fully cured. The composition will adhere to both sealing surfaces as it cures.

[0054] The curable composition can be used as a cured in place gasket (CIPG). In this application the composition is dispensed onto a first predetermined sealing surface and allowed to substantially cure before contact with a second predetermined sealing surface. The first sealing surface and cured composition is sealingly engaged with the second sealing surface thereby compressing the cured composition to provide a seal between the sealing surfaces. The composition will adhere to only the first sealing surface.

EXAMPLES

Example 1 :

Two-Component Polyacrylate Room Temperature Vulcanization (RTV)Formulation and Properties

Formulation:

Both materials are opaque pastes. Viscosity was measured at 25 °C, 10s ^-1 using a cone and plate in Rheometer Physica MCR301.

Testing methods: [0055] Gel time is measured based on ASTM D2471. Part A and Part B were loaded into a dual barrel cartridge and 50g of the mixed material was dispensed through a mixing tip into a 100ml beaker. Recording gel time until the material is no longer adhere to a clean spatula. Tensile properties are tested based on ASTM D412. Lap shear strength was tested based on ASTM D1002.

Properties of First Part and Seconds Part Mixed at a 1 :1 Ratio by Volume and after curing:

Example 2:

Two-Component Polyacrylate Room Temperature Vulcanization (RTV)Formulation and Properties

Formulation:

Both materials are opaque pastes.

Properties of First Part and Seconds Part Mixed at a 1 :1 Ratio by Volume and after curing:

Viscosity of the mixed components was not measured as the reaction and accompanying viscosity change was too fast to allow measurement.

Comparative Example 3:

Two-Component Silicone Room Temperature Vulcanization (RTV)Formulation and Properties

Formulation:

Properties of First Part and Seconds Part Mixed at a 1 :1 Ratio by Volume and after curing:

Example 4:

Standard Automotive Fluids Used for Immersion Testing

ATF = Dexron 6 Automatic Transmission Fluid

Engine Oil = SAE 5W-30 Engine Oil

Coolant = Dexcool Mixed 50%/50% with Water

The cured polyacrylate composition of Example 2 was immersed in ATF, engine oil and coolant for 1 ,000 hours. Results are shown in the following Table.

[0056] The cured silicone composition of Comparative Example 3 was immersed in ATF, engine oil and coolant for 1 ,000 hours. Shore hardness was measured based on ASTM D2240. Sample weight and volume change were measured comparing the sample weight and volume before and after immersion. Results are shown in the following Table.

[0057] The cured polyacrylate composition of Example 2 exhibited good property retention after 1 ,000 hours in the ATF, engine oil, and coolant. The cured silicone composition of Comparative Example 3 exhibited significantly more degradation after 1 ,000 hours in the ATF, engine oil, and coolant.

Example 5:

Shelf-Life Stability Testing

[0058] Example 1 first part and second part were separately tested for shelf-life stability by aging at 50 °C for times up to two months. After aging the first part and second part were reacted and gel time was determined as discussed above. The results are shown in the following Table.

These results indicate that that the polyacrylate composition of the invention was very stable (very little change from initial gel time) even after 2 months of aging at 50 °C.