FSELD ΟΨ THE DlSCL€SURE

fSOOl] The present disclosure relates fo wood substrates having surface defects treated with a putty composition having, inter aiia, enhanced self-leveling characteristics.

BACKGROUND

[0002] Currently, defects n ceiluiosic substrates are repaired by manually filling the defect with a curable composition. Subse uentl , the composition is cured; the outer surface of the substrate is optionally sanded arid subsequently coated. A disadvantage of this process is that it is performed manually and requires significant dry time. Filling the defects manually with a putty machine is a laborious process, which is expensive and time-consuming. In addition, the process is not suitable for a continuous production process.

[Θ003] Thus, there remains a need for compositions suitable for use in a continuous process which provides - i er alia ~ through-cure of putty compositions used to repair defects in ceiluiosic substrates. Embodiments of the present invention are directed to meeting these needs,

SUMMARY

10004] In some embodiments, the present invention provides a composite panel comprising a first major surface opposite a second major surface, the composite panel further comprising: a ceiluiosic substrate comprising a top surface opposite a bottom surface, the top surface forming a part of the first major surface, She eellulosic substrate comprising at least one defect that forms a depression in the top surface of the ceiluiosic substrate; and a cured polymeric composition formed from a putty composition comprising a first reactive component comprising a first, acry!ate oligomer; a second reactive component comprising a second acrylate oligomer, the second acrylate oligomer comprising a urethane acrylate oligomer; and an initiator component comprising a thermal initiator and a photo initiator, wherein the first reactive component and the second reactive component are present in a weight ratio ranging from about 4; 1 to about 1 ;2; and wherein the putty composition Is self-leveling; and wherein the cured polymeric composition occupies at least a portion of the depression,

[0 05] in other embodiments, the present invention provides a method of repairing ceiluiosic substrate comprising: (a) healing a ceiluiosic substrate having at least one defect that forms a depression in a top surface of the ceiluiosic substrate to a temperature of greater than about 35*C; (b) applying a putty composition to the depression, the putty composition comprising; a first reactive component comprising a first aery late oligomer; a second reactive component comprising a second aerylate oligomer, the second aery! ate oligomer comprising a ureihane aerykie oligomer: and an initiator component comprising a thermal initiator and a photo initiator, wherein the comers?, ratio of the first aery I ate oligomer to the second aerylate oligomer ranges from about 4; ! to about 1 :2; and wherein the putty composition is self-leveling; and ic) exposing the ceHuiosic substrate to a radiation source.

in other embodiments, the present invention provides a putty composition comprising: a first aerylate oligomer comprising a polyester aerylate oligomer, an epoxy aerylate oligomer, or a combination thereof; a second aerylate oligomer comprising a urethane aerylate oligomer; and an initiator component comprising: a thermal initiator; and a photo initiator; wherein the first aerylate oligomer and the second aerylate oligomer are present in a weight ratio that ranges from about 4: 1 to about 1 :2; and wherein the putty composition is self leveling; and wherein the potty composition has a viscosity ranging from about 500 cP to about 10,000 cP at about 25 °C.

[00Θ7] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCMFFIGN OF THE DRAWINGS

[CMMtgJ The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

MM] Figure ! is a perspective view of a composite panel containing surface defects that have been treated according to the present invention;

100 it]] Figure 2 is a cross-sectional view of the ceHuiosic substrate taken along line Π-Π in Figure I ;

[§©111 Figure 3 is a cross-sectional view of the composite panel taken along line l!-ll in Figure 1.

DETAILED DESCRIPTION

[0012] The following description of the preferred erabodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, Its application, or uses,

[0013] As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range, In addition, all references cited herein are hereby incorporated by referenced in their entireties.

In the. even! of a conflict in a definition in the present disclosure and that of a cited reference, ihe present disclosure controls.

£0014] Unless otherwise specified, all percentages and amounts expressed herein and elsewhere in the specification should be understood to refer to percentages by weight- The amounts given axe based on the active weight of the material. According to the present invention, the term "about" means +/- 5 % of the referenced value. According to the present invention, the phrase "substantially free" means less tha 0.5 wL % based an the referenced amount,

ί 00151 Referring to Figures 1-3 concurrently, the present invention provides a composite panel. 1 comprising a cellulosic substrate 100 and cured polymeric composition 200. The composite panel 1 may comprise a first major surface 2 opposite a second major surface 3 and side major surfaces extending there-between 4, The cellulosic substrate 100 may be formed from wood and comprise a top surface 102 opposite a bottom surface 103 and side surfaces 104 extending therebetween. The cellulosic substrate 100 may also comprise natural design features 330, such as a knot, burl wood-grain, or She like. The cellulosic substrate 100 may have a thickness t _s ranging from about 180 mils to about 1000 mils as measured from the top surface 102 to the bottom surface 103 - including ail values and sub-ranges there-bet ween, The. composite panel 1 may also have a thickness that is substantially equal to the thickness Is of the cellulosic substrate 100.

[001.6] The cellulosic substrate 100 may comprise surface defects 150 that form depressions in the top surface 102 of the cellulosic substrate 100. Each depression 150 may comprise a floor 151 and side wails 153 ~ with the floor 151 being the deepest point of the depression 150» The defects 150 may have a defect depth D;> as measured from the top surface 102 of the cellulosic substrate 100 to the floor 15 ! of the defect 150, where the defect depth D _D ranges from about 1 mil to about 100 mils - including all values and sub-ranges Iherc-between. The side walls 153 may extend upward from the floor 151 and intersect with the top surface 102 to the cellulosic substrate 100 at an intersection point 152 «- wherein the side waifs 153 may extend upward in a direction that is perpendicular or orthogonal to the top surface 102 of the cellulosic substrate 100. Each of the depressions 150 may have m opening distance Do which is the distance measured between the intersection points 152 that exist, on opposite side walls 153 for a single depression 150 in the cellulosic substrate 100. The opening distance Do of may range from about 0.1 inches to about 2.0 inches - ^■ · ^■ including ail values and sub-ranges there-beiween. [0017] According to ihe present invention, the defects 150 on the eellulosie substrate 100 may be repaired by filling the void created by each depression 150 with a putty composition which is cured to form a cured polymeric composition 200, thereby producing the cornposiic parse! 1 of the present invention. As used herein, the term "putty" refers to a soft, sticky, dough-like material that hardens after it is cured.

[0018] As demonstrated in Figure 3, ihe cured composition 200 may form a top repair surface 202 that faces the same direction as the top surface 102 of ihe eeliulosk substrate. The top repair surface 202 of ihe cured polymeric composition 200 and the top surface 102 of the ceilulosic substrate 100 may each form a part of the first major surface 2 of the composite panel. The top repair surface 202 may be substantially parallel to the top surface 102. The top repair surface 202 may be substantially co-planar with the top surface 102.

[0019] The putty composition of the present invention comprises a blend of first reactive component and a second reactive component. The first reactive component may comprise a first acrylaie oligomer and, optionally, a reactive diluent. The second reactive component may comprise a second acrylaie oligomer and, optionally, a reactive diluent. Each of ihe first and second acrylaie oligomers may be a linear or branched compound having an acrylaie functionality (the term "acrylaie" as described herein refers to compounds having either acr iate and/or (meih)acrylate functionality) ranging from about 2 to 9 -· including all values and subranges there-bct ecn. The reactive diluent ma be one or more compounds having an aerylafc functionality ranging from about 1 to 5 - including all values and sub-ranges there-between. Together, the first reactive component and she second reactive component react io form a polymer alloy that is particularly suitable as wood putty - as described further herein,

|002 ] The first reactive component comprising she first acrylaie oligomer creates may be an adhering oligomer and may comprise an epoxy acryiate oligomer, a polyester acryiate oligomer, or a combination thereof, The term adhering oligomer refers to reactive composition thai, when cured, provides rigidity and hardness lo ihe cured polymeric composition 200. The second acryiate oligomer may be a flexible oligomer and may comprise a urethane acryiate oligomer. The term flexible oligomer refers to reactive composition that, when cured, decreases the likelihood of cracking in the cured polymeric composition 200, The combination of the first and second acryiate oligomers create a polymer alloy exhibiting rigidity and flexibility required to for the resulting cured polymeric composition to be post processed using various mechanical means (as described further herein), without risk of cracking that would undermine the putty's ability to repair defects in cdlu!osic substrate ⁴ ?.

flMI21 | The first reactive component and ihc second reactive component may be present in a weight ratio ranging from about 4: 1 to 0: 1 i.e. its some embodiments the first reactive component may be optional. In other embodiments, the weight ratio of the first reactive component to the second reactive component m y range from about 4: 1 to about 1 :2 -«· including ail ratios and sub-ranges therebetween, in a preferred embodiment, the weigh! ratio of the first reactive component to the second reactive component may range from about 2: 1 to about 1 : 1 - including all ratios and sub-ranges there-between,

|0022| The first reactive component may be present in an amount ranging from about 40 wt. % to about 87 wt, % based on the total weight of the putty composition including all values and sub-ranges there-between. Irs other embodiments, the first reactive component may be present in an amount ranging from about 50 wt. % to about 70 wt. % based on the total weight of the putty composition · ^■■ including all values and sub-ranges there-between. In other embodiments, the reactive component may be present in an amount ranging from about 55 wt, % to about 65 wt. % based on the total weight of the putty composition - including ail values and sub-ranges therebetween

[§023] The first reactive component may comprise a polyester acrylate oligomer that is the reaction product of polyester polyol and a earboxvl ic acid functional acrylate compound such as acrylic acid, (meLh)acryltc acid, or a combination thereof « ^■ at an OH:COOH ratio of about 1 : 1. The polyester polyol may have a hydroxy! functionality ranging from 2 to 9■■■ ^■ including all values and sub-ranges there-between.

£0024] The polyester polyol may be the reaction product of a hydroxyl-functional compound and a carboxylic acid functional compound. The hydroxyl-functional compound is present in a stoichiometric excess to the carboxylic-acid compound. The hydroxyl-functional compound may be a polyol, such a dioi or a I i- functional or higher polyol (e.g. trioi. ictrol. etc.}., The polyol may be aromatic, cycloaliphatic, aliphatic, or a combination thereof. The carboxylic acid- functional compound may be a dicarboxylic acid, a poJycarfooxyiic acid, or a combination thereof. The dicarboxylic acid and polycarboxyiic acid may each be aliphatic, cycloaliphatic, aromatic, or a combination thereof. f 00251 The diol may be an aikyicne glycol , such as et lene glycol propylene gi> i, dkih lene glycol, dipropylene glycol, triethytene glycol. iriprttpylene glycol, hexylcne glycol, polyethylene glycol polypropylene glycol and neopentyl glycol; hydrogen ated bisphenol A; cyclohexanedio!; propanediol including 1 ^propanediol, 1,3-propanediol, usy! ethyl propanediol, 2-methy 1- 1 ,3-propanediot, and 2~eSbyl~2~bulyi- l .3-propanedio bulanedioi including 1.4-butanedioL 1.3 -butanedioi, and 2-clhyl < ^■ 1 ,4 buianedioi; pentanediol including mmeihy! pentartedio) and 2-nie hylpentanediol; eyctohexanedimedianoh hexanediol including 1.6 -hexanediol: cuproiactonediol (for example, she reaction product of cpsiion-caprolaetonc and ethylene glycol); hydroxy-alkylated bisphenol; polyether glycols, for example, poiv(oxytetramelhylGnc) glycol, In some embodiments, the iri-funcilonal or higher polyol may be selected from irimeShyloi propane, penSaeryihritoL di-pentaary hrito!. !rirncibylol ethane, irimethylol butane, dimethylol cyclohexane, glycerol and the like.

[0026] The diearboxylic acid may be selected from adipic acid, azelaic acid, sebaeic acid, succinic acid, gluSaric acid, decanoic diacM, dodeeanoic diacid. phihalic acid, isophthalic acid, 5- ieri-butyiisophthalic acid, tclrahydrophthalie acid, terephthalic acid, hexahydrophihahc acid, meOiyihe ahydrophtbalic acid, dimethyl Serephihalaie, 23-furarsdicarboxyiic ac d, 23- furandiearboxylic acid, 2,4-furandicarboxylic acid, 3,4-furandkarboxy3tc acid, 23,5- furanlricaihoxylic acid, 23,4,5~furanteiracarboxylie acid, cyclohexane diearboxylic acid, ehlorendie anhydride, 13 -cyclohexane diearboxylic acid, L4-cyelohcxanc diearboxylic acid, and anhydrides thereof, and mixtures thereof. In some embodiments Che polycarboxyiic acid may be selected from trimelHtic acid and anhydrides thereof.

[0027] Commercially available polyester acrylale oligomer include pol yester-acrylate resins such as: Craynor® UVP-215, Craynor® UVP-220 (both ex Cray Valley), Genomer® 3302, Genomer® 3316 (bolh ex Rahn), ), Sariomer CN2261, CN9005, Laromer® PE 44F, Laromer PE 56F, Laromer 8992, Laromer 8800 (ex BASF). Ebecryl® 800, Ebecryl® 810, Viaktin® 5979, Viak!in® VTE 5969, and Viaktin® 6164 (100%),

[0028] The first reactive component may comprise an epoxy aerylate oligomer. The epoxy aery hue oligomer may be prepared by reading cpichlorohydrin with bisphenol A So form diglycidyl ethers of bisphenol, followed by reacting the diglycidyl eiher of bisphenol product with acrylic acid and/or (meth)acrylic acid. The epoxy aerylate oligomer may be an aliphatic epoxy aery hue oligomer or an aromatic epoxy aerylate oligomer. The backbone of art aromatic epoxy aerylate oligomer may comprise ars epoxy compound thai includes one to three l _v 2~epoxy groups per molecule, and preferably, from about two to about two and one half (2.5) ! ,2-epoxy groups per molecule. A nan-Hrrtiling example of the epoxy aerylate oligomer may be a glycidyi eiher of a polyhydric phenol and polyhydric alcohol having an epoxide equivalent weight of from about 100 to about 500. The polyhydric phenol ma be bisphenol-A, bisphenol-F. or a combination thereof.

()29] In other embodiments, the epoxy aerylate oligomer may comprise a digiycidyi ether of tetrahromohisphenoi A, epoxy novoSacs based on phenol formaldehyde condensates, epoxy novolaes based on phenoi-eresoi condensates, epoxy novolaes based on phenol- dlcyelopeniadiene condensates, digiycidyi ether of hydrogenated bi phenoi A, digyleidyl ether of resorelnol, teiraglyddyl ether of sorbitol and te ra glycidyi ether of methylene dianiiine, as well as mixtures of Iwo or more thereof.

[003©] The second aerylate oligomer may be present in an amount ranging from about 12.5 wt. % to about 53 wt. % based on the total weight of ihe putty composition -~ including all values and sub-ranges there-between In other embodiments, the second aerylate oligomer may be present in an amount ranging front about 20 wt. % to about 50 wt. % based on Ihe total weight of the putty composition - including all values and sub-ranges there-between. In other embodiments, the second aerylate oligomer may be present in an amount ranging from about 25 wt. % to about 45 wi. % based on the total weight of She putty composition - including all values and sub-ranges there-between. In a preferred embodiment, the second aerylaie oligomer may be present in an amount ranging from about 20 wt. % to about 40 wt. % based on the total weight of the putty composition including all values and sub-ranges there-between.

'S . ^' f The second aerylate oligomer may comprise a urethane aerylate oligomer. The urethane aerylate oligomer may have an average acryiaie functionality ranging from about 2 to about 4 -·· including all values, and sub-ranges there-between,

[0032] The urethane aerylate oligomer may be the reaction product of polyisocyanate, one or more high molecular weight po!yoL and a hydroxyl functional aerylate. The urethane aerylate oligomer may be produced by reacting the polyisocyanate and the hydroxyl-fone ional compounds at an CO:OH ratio ranging from about 0.8: 1 to about 1.2: i preferably a! about 1 : 1 . f§§33] The polyisocyanate may have an isocyarsate-funelionality ranging from about 2 to about 4. Non- 1 smiting examples of polyisocyanate include aliphatic polyisocyanate, cycloaliphatic polyisocyanate, and/or aromatic polyisocyanaie - such as -(etramethyiene diisocyanate. 1 ,6- hexarnethylenc diisocyanate, 1,4-cyelohcxyl diisocyanate and isophorone diisocyanate, 4,4' diphenyhmethane diisocyanate and toluene diisocyanates. Polyisocyanate having an isocyanaie functionality of 3 or 4 ma include triisocyanates and isocy an urates of 1 ,6-hexamcthyiene- diisocyanate arid isophorone diisocyanate may be used,

[§§34] The high molecular weight polyol may have a hydroxy! functionality ranging from about 2 to about 4, Non-limiting examples of high molecular weight poiyo! include polyester polyol, polyether polyol, polyolefin polyol, and polycarbonate polyol having an average hydroxyl functionality ranging from about 2 Co about 4. The polyester polyol used to create the urethane acryiate oligomer may be the same as the polyester polyol used to form the polyester acryiate oligomer.

[§§35] The hydroxyl-func ionai acryiate may have a hydroxy! functionality from about I to about 2 and an acryiate functionality from about I to about 3. Non-limiting examples of hydroxy! functional acryiate include the reaction product of acrylic acid and/or (meth)acrylic acid and a low molecular weight diol or polyol In some embodiments, the low molecular weight diol Is selected from monoethyleue glycol 1 ,2- and 13-propylenc glycol, 1,4- and 2.3-bulylcnc glycol, LS-pentancdiol, 1 ,6-hcxanediol, Ι,Β-ociancdtoi. deeanediol dodecanedioL neopentylglycol, eydohexanedioi and mixtures thereof, in some embodiments, the polyol is selected from penlacrythritol. neopentylglycol, dicidol, irimethyiolpropane, and mixtures thereof. In some embodiments, the diol and polyol may contain alky! branching or hydroxylalkyl branching such as trimeihylolpropane. In other embodiments, the polyol comprises a mixture of a polyol having a hydroxyl functionality of three or greater and a diol In other embodiments, the polyol may have a chain length of from C; to€ or from Q to j, between the hydroxyl groups, [0036] Each of the first reactive component and the second reaesive component may independently comprise a reactive diluent. The reactive diluent may be present in the first reactive component in sm amount ranging from about 0 wt. % to about 20 wL % based on the total weight of each of the first reactive component. The reactive diluent may be present in the second reactive component in an amount ranging from about 0 wt, % to about 20 wt. % based on the total weight of each of the second reactive component.

S IIK137] Reactive diluents are compounds Ibat serve a dual purpose: such compounds are not onl capable of covalently bonding wish acry!ate- unci tonal oligomer but arc also capable of reducing the viscosity of the overall putty composition. The reactive diluents may have number average molecular weights of about 226 to about 2000 ^■ · ^■ · ^■ · including all values and sub-ranges therebetween. The reactive diluent may have an acryiatc functionality ranging from 1 to 5 - including all values and sub-ranges there-between.

[0I 3S] vSuitable reactive diluents include, hut are not Hmiled io, {meth)acrylic acid, isodecyl (mcth)acrylatc. N-vinyl formamidc. isobornyl (meth)aeryUUc. tctracthyicnc glycol (melh)aerylate. iripropylene glycol (mclhtecrylate. hexancdiol di(meih)acrylate, eihoxylate bispbenol-A di(tneth)acry!aie. ethoxytated neopeaty! glycol di(meth)acryiate, propoxyiated neopentyl glycol di(rneth)acrylate, ethoxylafed Iripropylene glycol di(melh)acrylate, glyceryl propoxyiated tri{mcth acryiatc. Iris (2-hydroxy ethyl) isocyanurate tri(meih)acryiate, pentacrythrilol triimethjacrylate, pentaerythrilol teira(mcth)acrylatc: _> dimethylol propane lri(meth)acrylate dipentaerythritol monohydroxypenta(meth)acry¼e, and trimethylol propane tri(mcth)acry!atc and its ethoxylatcd and propoxyiated analogues of the skeletal structures in Formula 3:

o

100391 Where R"~H, or CH¾ and c O. 1, 2, 3. 4. 5, 6, 7, 8. 9 or 10.

ΙΌΘ4Θ) The preferred (meth)acrylaie reactive diluents arc the multifunctional acrylates with number average molecular weights of about 226 to about 2000. Examples of such are tetraclhylene glycol diacrylate with a molecular weight of about 302, eihoxylated bisphenol~A diacrylate with a number average molecular weight of about 776 (SR602 from Sartomcr Company), Irihydroxyethyl isocyanurate tri ^' acrylate with molecular weight of about 423 (SR368 from Sartomcr). trimethylol propane triacrylate with a number average molecular weight of about 296 (SR351 from Sartomcr). and eiJhoxylatcd trimethylol propane Iriacryialcs with number average molecular weights from about 400 to about 2000 (SR454, SR499, SR502, SR 035, and SR 415 from. Sartomer Company and Photomer 4155 and Photomer 4158 from Henkci Corporation). Tetra-iunetional reactive diluent may com r s pentaeryhritol tetraacrylate, Pertta-functional reactive diluent may comprise dipentaeryhritoi pcntaacrylatc.

[ΘΘ41] Additionally, when, the reactive composition comprises an epoxy-based oligomer, the reactive composition may further comprise an epoxy flcxibiiizer. Nors- limit ng examples of flexibilazer includes rubber-modified bisphenol A epoxies, epoxidized castor ad based epoxies, and epoxies which are modified with dimer .ed fatty acids, as well as mixtures thereof.

[00421 The putty composition further comprises an initiator component comprising a mixture of thermal initiator and a photo initiator. The mixture of thermal initiator and photo initiator provides a dual cure mechanism to the putty composition (e.g.,. curing by hea and UV radiation) thai ensures fast and proper through-cure of the putty composition to form the cured polymeric composition 200, The term "through-cure" indicates thai the substantially alt of the putty composition that has been applied to one or more defects 150 in the celhdosic substrate 100 has been chemically cured by cross-linking of the free aerylate groups present on the first acr kfe oligomer and the second acryiate oligomer (and, optionally, the third aerylate oligomer), thereby- forming the cured polymeric composition 200.

[0043] The dual cure mechanism of the present invention results in through-cure for putty compositions applied to depressions having a defect depths Do as high at 10 mils. Unlike the soft, sticky, dough-like putty composition, the cured polymeric composition 200 is a rigid, non- tacky material at room temperature that has a hardness of at. least the surrounding cellu!osie substrate 100. Therefore, the dual cure mechanism provides fast and efficient formation of the cured polymeric composition 200 throughout the substantially the entire defect 150 (up to defect depths Do of 100 mils), which in-iurn allows for fast and efficient post-processing of the composite panel 1 (e.g., milling, surface sanding, abrading, etc.) as the cured polymeric composition 200 can quickly be post-treated in the same way that cellulosie substrate 100 without special concern to a partially cured putty composition.

[0044J The thermal initiator may be present in an amount ranging from about 0.05 wt. % to about 2 wt. % based on the total weight of the putty composition -- including all values and subranges there-between, In some embodiments, the thermal initiator may be present in an amount ranging from about 0.1 wt, % to about 1.5 wt, % based on the total weight of the putty composition · ^■ ·· ^■ ·. including all values and sub-ranges there-between. In other embodiments, the to thermal initiator may be present in an amount ranging from aboat 0.2 wt. % to about 1.25 wt. % based on the total weight of the putty composition ~ including all values and sub-ranges therebetween. In further embodiments, the thermal initiator may be present in an amount ranging from atom 0.3 wt. % to about 1 .25 wt. % based on the total weight of the putty composition - incl ding all values and sub-ranges there-bet een, n other embodiments, the thermal initiator may be present in an amount of about 0.5 wt. % based on the total weight of the putty composition. In other embodiments, the thermal initiator may be present in an amount of about 0.6 wt. % based on the total weight of the putty composition. In other embodiments, the thermal initiator may be present in an amount of about 0.7 wt. % based on the total weight of the putty composition. In other embodiments, the thermal initiator may be present in an amount of about 1.1 wt. % based on the total weight of the putty composition,

f.CK 5J The thermal initiator may comprise a free radical initiator that generates radicals upon exposure to heat rather Shan light. The thermal initiator may be selected from a peroxide compound, an a/.o compound, and a combination thereof. Non-limiting examples of am compounds include 2,2'-azobis-{2,4-dimeihylvaleroaiiFiie), azobisisobutyronitrile, azobis isoheptanon siri !e, azobisisopentanonitrile, and 2,2"-¾obis-(2~methylbutyronitrile ; ) . ; ^' ·· azobis-( 1 -cyciohexanecarboEiitri!e).

[0046] Non-limiting examples of peroxide initiators include diaeyl peroxides, such as 2-4- diclorobenzyl peroxide, diisononanoyl peroxide, decanoyl peroxide, lauroyl peroxide, succinic acid peroxide, acetyl peroxide, benzoyl peroxide, and diisobutyryl peroxide, acetyl aikylsulfcsnvl peroxides, such as acetyl cyclohexylsulfonyl peroxide, diaSkyl peroxydicarhonates, such as di(n~ propyl) peroxydicarbonate, αίί sec-butyl) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, t-butybperoxymaleie acid, diisopropyl peroxydicarbonate, and dicyclohexyl peroxydicarbonate, peroxy esters such as alpha-cumyl peroxyneodeeanoate, a!pha-eumyi peroxypivalate, t-amyi peroxyneodeeanoate, t-butyl peroxyneodeeanoate, t-amyl peroxypivalate, i-hutyi peroxypivalate, 2,5-diraeihyl-2,5-di(2-ethylhexanoylperoxy)hexane, t-amyIperoxy-2-elhyi hexanoate, t-butyl peroxy~2~ethyl hexanoaie, t-butyl peroxyisobntyrate, t-butyl peroxy acetate, t-butyl peroxybenzoate, di-i-buiyl dlperoxy azelate, and dl~t-butyl di eroxy phthalate, dicumyl peroxide, 2,5-dimethyl~2,S-di(t~butylperoxy)hexane, t-butyl enmyi peroxide, di-t-butyi peroxide, artd 2,5- dimethyl, 2,5-di(t-buiylperoxy)hexyne-3, a hydroperoxide, such as 2,5-dihydroperoxy-2,5- dirnethyl hexane, eumene hydroperoxide, t-butyl hydroperoxide and t-amyi hydroperoxide, n~ butyl-4,4-bis-{t-butyJperoxy)valerate, I , l-di(t-bu ⁽ yiperoxy)-3,3,5 rimelhyI cyclohexane, 1 ,Γ-di- t-amyl-peroxy cyclohexane. 2,2-di(i-buiy1pcroxy) butane, e{hyI"33~di(t-buty!peroxy)butyrale. t« biity! peroctoate, and I„ 1 -di{t-bu.yIperoxy)cyclohexane.

IIW471 The photo initiator may be water soluble and include bcazophenone-type initiators, phosphsoc oxides, aeetophenone derivatives, and caiionic photo initiators such as triaryl sulforuum salts and aryliodonium sails, The photo initiator ma be selected from benzophen ne; 4-rnethylbenz:ophenone; benzyl dimethyl ketal; diethoxy aeetophenone; benzoin ethers; thioxanthones; 1 --hydroxycyclohexyl phenyl ketone; 2 i drox y*2-methyl- 1 -phenol-propane- i - one; 4-(2-hydroxyethox.y)phenyl"{2"hydroxy-2 ^» melhylpsOpyl) ketone; 2.4,6-irime hyIbenzoyi dipheny!phosphine oxide; bis (2,6-dimethoxybenEoyl)--2«4.4 rimethylpentyI phasphine oxide; 2,2-dimethoxy-2~phenyl aeetophenone; 2,2-o!imethoxy- l ,2-diphenykmani ^» !-one; his(2A6- trimcihylbersTOyl) -phenyl phosphineoxide; 2-benzy!-2-N,N SirneihyIamino- l -(4- morphoUnophenyl)- 1 -butanone; and 2"meth l-[4-{mεth H iQ) heo Ij-2~moφhoHno propan-1- one. and a combination of two or more thereof,

[0048] The phoio initiator may be used alone or in comb nation with other phoio initiators. The putty composition may further comprise phoiosensiiizers. Non-limiting examples of photosenskker include isopropyl ihioxanthone, cMorothioxanthone, quinones such as camphorq trtone; 4,4 -bis(diniethylamino)ben20phenone; 4,4'-bisdieibylamin beruop!tenone ethyl ketone; tMoxanthone. bcnzi¾nthtone, triphcnyl aeetophenone and fi orenone. dirnethyiethanola ine, methyldletharsolamme, triethano! amine, N,N-dimethyl-para oinidine, N- [2~hydroxyeihylJ ^» N-methyl-para o dine, oetyl~para-N,N' imethylamino henxoato. and ethyl- para~N«N-dimethylarnino benzoate,

ITO49J The putty composition of the present invention may be substantially free of thiol- functional compounds. According to some embodiments, the putty composition of the present invention may he entirely free of ihiol-funetion l compounds (i.e. comprise 0 wi. % of thiol- functional compounds based on the total weight of the putty composition). The putty composition of the present invention ensures fast and proper through cure of the putty composition to form the cured polymeric composition 200 even without the addition of ihioi- functional compounds, such as triUhioL

[0050] The putty composition may further com rise a solvent. Non-limiting examples of solvent include an aromatic solvent, such as toluene or benzene; and a non-aromatic solvent, such as acetone, chloroform, dichforomethane, efhylacetate, or methyl methacrylaie, In some embodiments, the solvent comprises acetone.

|0§S1] The solvent may be present in an amount ranging from about 0.5 wt.% to about 5 wt,% based on ihe total weight of ihe putty composition ~ including all values and sub -ranges there between, in other embodiments, the solvent may be present in an amount ranging from about 1 wt.% to about 3 wt.% based on the total weight of the putty composition - including all values and sub-ranges there-bet ween. In other embodiments, the solvent may be present in an amount ranging from about 1 .2 wt.% So about 2.8 wt.% based on the total weight of the putty composition - including ail values and sub-ranges there-between. In some embodiments, the so!venl may be present in an amount of about 1 ,2 wt. % based on the total weight of the putty composition. In some embodiments, the solvent may be present in an amount of about 1.8 wt. % based on the total weight of the putty composition. In some embodiments, the solvent may be present in an amount of about 2.6 wt. % based on the total weight of the putty composition. [IM)S2| The solvent and the thermal initiator may be present in the putty composition in a weight ratio that ranges from about 5: 1 to about 1 : 1 ^■ ■ ^■ ■ ^■ including all ratios and sub-ranges there-between. In a preferred embodiment the solvent and the thermal initiator may be preset in the putty composition in a weight ratio ranging from about 4: 1 to about 2,5: 1■ ^■ ■ ^■ ■· including all ratios and sub-ranges there-between.

[$053] When preparing the putty composition of the present invention, the thermal initiator and solvent may be pre-blended before being added to the first and second acsyla e oligomers. Specifically, the thermal initiator may be substantially dissolved in the solvent prior to being added to the first and second acrylate oligomers.

f 003 1 The putty composition of the present invention may further compose pigments and colorant and, optionally, surfactant. The pigment may be present in an amount ranging from about 3 wt, % to about 8 wt. % based on the total weight of the putty composition - including all values and sub-ranges there-between. The pigment may include particles that impart yellow, red, green, blue, black, and combinations thereof, to the putty composition. The surfactant may be present in an amount ranging front about O. i wt. % to about 1 wt. % based on the total weight of the putty composition - including all values and sub-ranges there-between.

[IM SS] In preferred embodiments of the present invention, the putty composition may be substantially free of filler. Irs alternative embodiments, the putty composition may comprise filler. Non-!imiUf!g examples of filler include glass fill, flour, calcium carbonate, barium sulfate, mica, ammonium chloride, ammonium bromide, boric acid, ant mon trioxide, alumina (e.g. turned alumina), clays such as kaolin, china clay, tithopone, zinc sulfide, zirconium oxide, barium oxide, calcium oxide or hydroxide, magnesium silicate, oxide or hydroxide, ceramic, hollow glass, resin microspheres, pearl essence, baryies, diaiomaceous earth, aluminum irihydrate. onyx floor, magnesium silicate ("talc"), calcium silicate, mixed silicates, and the like.

[0056] The putty composition of ihe present invention may have a Brookfle!d viscosity ranging from about 500 cP to about 10,000 cP, at about 25 *C. fa other embodiments, the putty composition may have a Brook fie Id viscosity of from about 1,000 cP to about 5,000 cP, at about 25 ^c €. In other embodiments, the putty compositions may have a Brookfield viscosity of from about 2.000 cP to about 5.000 cP, at about 25 ⁹ C The putty composition may further comprise a viscosity modifying agent in an amount effective such thai the putty composition exhibits the desired viscosity. Non-limiting examples of viscosity modifying agent comprises fumed silica and/or a dlspersant.

[0057] The putty composition of the present invention is formulated to be sc H- leveling. The term "self-leveling" refers to a composition that can fill one or more depressions 1.50 on the celtnlosic substrate 100 under the effect of only gravity and without the need for using physical tools (e.g., a putty knives, air blade, vacuum suction) to further manipulate the putty composition after application to the celkdosic substrate 100, Specifically, self-leveling will cause the putty composition to settle within the depression 150 and form a putty top surface that is substantially parallel to the top surface 102 of the cc!!uiosic substrate 100 under the effect of only gravity.

[0058] After curing, the top surface of the putty composition becomes the top repair surface 202 of the cured polymeric composition 200. Therefore, the self-leveling of ihe putty composition provides a fast and efficient way to create a desirable the top repair surface 202 because the application of the putt composition can be immediately followed by initiation of the dual curing mechanism without the need for intermittent physical manipulation of the putty composition that would otherwise be required to ensure the resulting top repair surface 202 is parallel to the top surface 102 of the eeilulosie substrate 100. Furthermore, with an effective amount of putty composition applied to the defect 150, the self-leveling can provide a top repair surface 202 that, is substantially co-planar with the top surface 102 of the eeilulosie substrate without need for additional processing, such as sandirsg or abrading of the cured polymeric composition 200, thereby reducing manufacturing time and energy, as welt as saving on material cost,

| ⁽ M)59] The pu!iy composition may be formed by combining the first acrylaie oligomer, second acryiate oligomer, thermal and photo init ato s, solvent, and optionally, pigments, and surfactant. In some embodiments, the thermal initiator may be pre-dissolved in the solvent before being added to the other components of the putty composition.

f 00601 The composite panel 1 may be formed by beating a celiulosic substrate 100 thai has at least one defect 150 on the top surface 102 to a temperature of greater than about 3 ' C. la some embodiments, the celiulosic substrate may be heated to a temperature of from about 37 ^S C to about 70 *€. In other embodiments, the celiulosic substrate may be heated to a temperature of from about 57 *C to about 68 °C. The bottom surface 103 of the celiulosic substrate 100 may faee an upper surface of a conveyor belt or other work surface. The putty composition may be applied to the defect 150, where the putty composition then self-levels under gravitational pull (whereby gravity is pulling in a direction extending from the top surface 102 toward the bottom surface 103 of the celiulosic substrate 100). The putty composition may be at room temperature when it self-levels.

[0061] During one or more stages of the manufacturing process, the celiulosic substrate 100 may be placed on a conveyor belt that has a line speed of from about 10 feet/mir ie (fpm) to about 70 fpm - including all values and sub-ranges S here-bet ween. In some embodiments, the conveyor belt has a line speed of from about 20 fpm to about 60 fpm Including all values and sub-ranges there between. In some embodiments, the conveyor belt has a line speed of from about 30 fpm to about 50 Fpm ^■ ■ ^■ ■ ^■ · including all values and sub-ranges there-betweem In some embodiments, the conveyor belt has a line speed of about 35 fpm. In some embodiments, the conveyor belt has a line speed of 33 fpm. Specifically, the self-leveling and dual cure mechanism of the putty composition allows for faster manufacture of the composite panel 1.

[©062] Once ihe putty composition is applied to the defect 150, the putty composition self-levels to form the putty top surface without the need for the application of external pressure on the putty top surface from an external top layer or top film. The celiulosic substrate 100 may then he exposed to a radiation source and the putty composition cures to form the cured polymeric composition 200 within the celiulosic substrate 100, thereby forming the composite panel 1 of the present Invention. The putty top surface may be exposed to atmospheric conditions during curing. Stated otherwise, ihe putty lop surface is not covered by an external m mbrane or protective film / layer during exposure to the UV radiation during curing. Rather, the patty top surface of the patty composiiion and at least a portion of the top surface 102 of the cei!u!osic substrate 100 are exposed lo the surrounding atmospheric conditions daring curing. Thus the top putty surface forms the iop repair surface 202 while exposed to atmospheric conditions and not under the protection of an externa! layer and/or membrane.

[0063] The cellulosic substrate 100 having the patty composiiion applied thereto can be cured by- conveying the cellulosic substrate 100 along the machine direction wherein the radiation source is located above the cellulosic substrate 100 and conveyor belt, facing downward. As the cellulosic substrate 100 and putty composition applied there to pass underneath the radiation source,, the putty composition is exposed to the UV radiation that is emitted from the radiation source.

10064] The radialion source may comprise ultraviolet radiation as measured using an EFT radiometer in the UVA regime, The radiation source may be a UV lamp that emits UV radiation having a peak irradiance ranging from about 350 mW/crn" to about 20 W/cm~ --- including ail values and sub-ranges there-between. In some embodiments, the radiation source may emit UV radiation having a peak irradiance ranging from about 350 mW/cm" to about 2,000 mW/cm ² ~ including all values and sub-ranges there-between. h a preferred embodiment, the radiation source may emit UV radiation having a peak irradiance ranging from about 350 mW/em~ to about 1,000 mW/csif - including all values and sab-ranges there-between. The radiation source may be a mercury vapor UV lamp or an LED emitting radiation lamp, wherein the radiation that Is emitted has a wavelength in the range of about 350 nm to about 400 nm - including all values and sub-ranges ihere-hetween. The LED may emit radiation at a wavelength ranging from 365 nm to 395 nm and have a LED peak irradiance as high as 20 W/em~ using a Nobel Probe.

[§065| Moving along the machine direction at ihe above referenced line speed, the putty composition applied to the cellulosic substrate 100 can he cured with UV radiation from the radiation source, wherein the UV radiation output required to cure the putty composition (including complete through cure) totals to an amount ranging from about 300 mJ/cra ^" to about 1000 mJ cnr - including all values and sub-ranges there-between. Additionally, the putty composition may be cured with as little as a single pass under the radiation source. In other embodiments, the cellulosic substrate 100 having the putty composition applied thereto may be cured by passing underneath Ihc radiation source with multiple passes e.g., 2 to 10 passes «- including all value and sub-ranges there-between.

fOI ¾1 The radiation source may comprise one or more UV lamps {including an LED) having a UVA output of greater than about ?GGmJ/cm"„ The radiation source may be an LED emitting radiation having a wavelength in the range of about 350 am to about 400 nm - including all values and sub-ranges there-between wherein the LED may emit radiation at a wavelength ranging from 365 ntrs to 395 am and have a LED peak irradiance as high as 20 W/cnr,

[0067] The composite panel I may then be cooled at a surface temperature ranging from about 54 ³ C to about 63 ^C C - including all temperatures and sub-ranges there-between.

[0068] In a preferred embodiment, the eellulosic substrate 100 having the putty composition applied thereto can he cured with a single pass under the radiation source, which provides for a continuous manufacturing process of flooring materials and products that further includes defect repa r. Slated otherwise, using the putty composition of the present invention provides a useful way to repair surface defects 150 in eellulosic substrates 100 without having to temporarily separate the eellulosic substrate 100 from a continuous manufacturing process ~ e.g., stopping inline flooring material manufacture so thai a eellulosic board may he removed from the in-line production and relocated to a separate Isolated repair process. Rather, defects 150 In eellulosic substrates 100 can be repaired along the overall continuous manufacturing process such thai the defects ca be repair immediately after the initial processing of the eellulosic board (e.g., board milling) and immediately before further processing steps (e.g.. board sanding, additional cutting, surface siainirsg and/or sealing) without the need to pause the overall manufacturing process for surface defect repair. With a single pass, the defects in the eellulosic substrate can be repaired along a conveyor otherwise intended to shaping, sanding, and /or staining the eellulosic substrate In an effort to create a flooring material

|0§6 ] In non-limiting embodiments, a flooring panel may comprise the composite panel I of the present invention, The flooring panel may further comprise an underlayment applied to the second major surface 2 of the composite panel 1 , The flooring panel may further comprise a wear layer applied So the first major surface 1 of the composite panel 1 ,

[0070] The invention will be described in greater detail by way of specific examples, The following examples are offered for illustrative purposes and are not intended to limit the invention in any manner. EXAMPLES

[ M 71] Described in Tables 1 and 2 (below) are the compositions of four (4) exemplary putty compositions of the present invention {Ex, ! - Ex.. 4), along with the compositions for three (3) comparative putty compositions (Comp. Ex. I Contp. Ex. 3).

[0072] Each sample was prepared by first performing a pre- heat step to each ceUu!osic substrate before application of the putty composition. The pre-heat step included passing the cdlulosk substrate under UV lamps to achieve a board surface temperature (BST) of 37 ^C C to 55 °C prior to application of the putty compositions. Subsequently, each putty composition was applied to and filled defects on a cdlulosk substrate by using either a plastic dropper or another dispensing device. The defects included knot holes having a depth of about 80mH. The board was then assed under UV lamps with a IJVA output of 730mJ/cm~ using an ΕΓΓ Power Puck.

t

i ffMt?3] As shown in Tabic I, the exemplary compositions of the presenl invention (Ex, ! - Ex. 4) have no perceivable cracks upon cooling and demonstrate through cure; whereas Comp. Ex. I and 2 become brittle upon cooling and crack; and Comp. Ex. 3 does not demonstrate through cure. A putty composition that cracks upon cooling, or fails to demonstrate through core. Is unacceptable.

10074] It is intended thai any patents, patent applications or printed publications, including books, mentioned in this patent document be hereby incorporated by reference in their entirety.

[00751 As those skilled in the art will appreciate, numerous changes and mod iff cations may be made to the embodiments described herein, without departing from the spirit of the invention. It is intended thai all such variations fall within the scope of the invention,

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