CURABLE COMPOSITIONS

Abstract

Useful articles, such as coatings, adhesives, printed graphics, 3D printed articles and molded articles are prepared by curing compositions containing one or more salts of ethylenically unsaturated carboxylic acids comprising six or more carbon atoms, one or more multifunctional (meth)acrylate oligomers and one or more mono(meth)acrylate esters of alcohols which, when polymerized as homopolymers, have glass transition temperatures of at least 50 C.

Claims

1. A curable composition comprised of: a) at least one salt of at least one ethylenically unsaturated carboxylic acid comprising six or more carbon atoms b) at least one multifunctional (meth)acrylate oligomer and c) at least one mono(meth)acrylate ester of an alcohol which, when polymerized as a homopolymer, has a glass transition temperature of at least 50 C. as measured by Dynamic Mechanical Analysis in accordance with ASTM E1640-13,

2. The curable composition of claim 1, wherein the ethylenically unsaturated carboxylic acid is comprised of seven, eight, nine, ten, eleven, twelve, thirteen or more carbon atoms.

3. The curable composition of claim 1, wherein the ethylenically unsaturated carboxylic acid contains at least one functional group selected from the group consisting of acryloyl, methacryloyl, allyl, propenyl and vinyl,

4. The curable composition of claim 1, wherein the ethylenically unsaturated carboxylic acid is a (meth)acrylate-functionalized carboxylic acid.

5. The curable composition of claim 1, wherein the at least one salt comprises at least one polyvalent metal salt.

6. The curable composition of claim 1, wherein the at least one salt comprises at least one zinc or calcium salt.

7. The curable composition of claim 1, wherein the ethylenically unsaturated carboxylic acid is a half ester which is a reaction product of a hydroxy-functionalized ethylenically unsaturated compound and a polycarboxylic acid or carboxylic acid anhydride.

8. The curable composition of claim 1, wherein the salt corresponds to Formula (I):
M(OC(O)CR.sup.1CH.sub.2).sub.x(OC(O)R.sup.2C(O)OR.sup.3OC(O)CR.sup.4CH.sub.2).sub.y (I) wherein M is an element other than hydrogen of valence n, n=x+y, y=an integer of at least 1, R.sup.1 and R.sup.4 are the same or different and are H or CH.sub.3 and R.sup.2 and R.sup.3 are the same or different and are divalent organic moieties each containing two or more carbon atoms,

9. The curable composition of claim 8, wherein M is selected from the group consisting of Li, Na, K, Ce, Mg, Ca, Sr, Ba, Ti, Zr, V, Cr, Mo, W, Mn, Fe, Co, Ni, Pd, Cu, Zn, Cd, Hg, B, Al, Ga, In, Si, Ge, Sri, Pb, Sb and Bi.

10. The curable composition of claim 1, wherein the at least one mono(meth)acrylate ester of an alcohol, when polymerized as a homopolymer, has a glass transition temperature of at least 75 C. as measured by Dynamic Mechanical Analysis in accordance with ASTM E1640-13.

11. The curable composition of claim 1, wherein the at least one multifunctional (meth)acrylate oligomer is selected from the group consisting of urethane (meth)acrylates, epoxy (meth)acrylates, polyester (meth)acrylates, polyether (meth)acrylates, polycarbonate (meth)acrylates and combinations thereof.

12. The curable composition of claim 1, wherein the at least one multifunctional (meth)acrylate oligomer comprises at least one di(meth)acrylate-functionalized oligomer.

13. The curable composition of claim 1, wherein the at least one multifunctional (meth)acrylate oligomer has a number average molecular weight of from about 100to about 10,000 daltons.

14. The curable composition of claim 1, wherein the alcohol contains at least one of a cyclic structural moiety or a hydroxyalkyl structural moiety.

15. The curable composition of claim 1, wherein the alcohol contains at least one of a cyclic structural moiety selected from the group consisting of aromatic groups and alicyclic groups.

16. The curable composition of claim 1, wherein the alcohol contains at least one of a cyclic structural moiety selected from the group consisting of monocyclic, bicyclic, tricyclic, tetracyclic, pentacyclic and hexacyclic hydrocarbon radicals.

17. The curable composition of claim 1, wherein the alcohol contains at least one of a cyclic structural moiety selected from the group consisting of isobomyl, cyclohexyl, tricyclodecanyl and phenyl.

18. The curable composition of claim 1, wherein the salt is obtained by reacting a M-containing compound, wherein M is an element selected from the group consisting of Li, Na, K, Ce, Mg, Ca, Sr, Ba, Ti, Zr, V, Cr, Mo, W, Mn, Fe, Co, Ni, Pd, Cu, Zn, Cd, Hg, B, Al, Ga, In, Si, Ge, Sn, Pb, Sb and Bi, with a carboxylic acid corresponding to Formula (II):
HOC(O)R.sup.2C(O)OR.sup.3OC(O)CR.sup.4CH.sub.2 (ii) wherein R.sup.4 is H or CH.sub.3, and R.sup.2 and R.sup.3 are the same or different and are divalent organic moieties each containing two or more carbon atoms.

19. The curable composition of claim 18, wherein the M-containing compound is selected from the group consisting of M-containing oxides, M-containing halides, M-containing alkoxides, M-containing hydroxides, M-containing nitrates, M-containing sulfates, M-containing carboxylates, M-containing carbonates and combinations thereof.

20. The curable composition of claim 18 or 19, wherein the M-containing compound is zinc oxide or calcium oxide.

21. The curable composition of claim 18, wherein the salt is obtained by reacting the M-containing compound with both the carboxylic acid corresponding to Formula (II) and (meth)acrylic acid.

22. The curable composition of claim 1, comprising 1 to 25% by weight a), 20 to 55% by weight b) and 25 to 60% by weight c), based on the total weight of a)+b)+c).

23. A method of making a cured article, comprising curing a curable composition in accordance with claim 1.

24. A method of making a three-dimensional article, comprising the steps of: a) coating a first layer of a curable composition in accordance with claim 1 onto a surface; b) at least partially curing the first layer to provide a cured first layer; c) coating a second layer of the curable composition onto the cured first layer; d) at least partially curing the second layer to provide a cured second layer adhered to the cured first layer and e) repeating steps c) and d) a desired number of times to build up the three-dimensional article.

25. The method of claim 24, wherein the curing steps are performed by exposing the layers of the curable composition to radiation.

26. A method of making an adhesive, a sealant, an ink, a 3D printing resin, a composite or a molding resin comprising the use of a composition in accordance with claim 1.

27. A cured finished product obtained by curing a curable composition in accordance with claim 1.

28. The cured finished product of claim 27, wherein the cured finished product is selected from the group consisting of coated articles, adhered articles, sealed articles, 2D printed articles, 3D printed articles, composites and molded articles.

Description

EXAMPLES

Example 1

[0122] In this Example, the effects of introducing different amounts of an oil-soluble zinc diacrylate into a curable composition in accordance with the present invention were evaluated.

[0123] The base (comparative) curable composition (1-A) contained 45% by weight CN966, 55% by weight SR506 and an added 1% of Irgacure 819 photoinitiator. CN966 and SR506 are commercial products sold by Sartomer having the following compositions: [0124] CN966: a difunctional urethane acrylate oligomer having a molecular weight of about 3000 daltons. [0125] SR506: isobornyl acrylate (a high Tg (meth)acrylate that in homopolymerized form has a Tg of about 94 C., as measured by Dynamic Mechanical Analysis).

[0126] Curable compositions 1-B, 1-C and 1-D in accordance with the invention were prepared, as shown in Table 1. The zinc diacrylate used in these compositions was obtained by reacting zinc oxide with a 1:1 mixture of acrylic acid and the half-ester formed by reacting hydroxyethyl acrylate with hexahydro-4-methylphthalic anhydride. The structure of the zinc diacrylate may be represented by the following formula:

Zn(OC(O)CHCH.sub.2)(OC(O)R.sup.2C(O)OCH.sub.2CH.sub.2OC(O)CHCH.sub.2)

wherein R.sup.2 is a 1,4-cyclohexyl moiety substituted with a methyl group at the 4 position.

TABLE-US-00001 TABLE 1 Component 1-A 1-B 1-C 1-D CN966 45 wt % 45 wt % 45 wt % 45 wt % SR506 55 wt % 45 wt % 40 wt% 35 wt % Zinc Diacrylate 0 wt % 10 wt % 15 wt % 20 wt %

[0127] The formulations were cured between two pieces of glass to prevent any oxygen inhibition. The samples were cured with two passes at 50 ft/min on a conveyor belt, one on each side, under a 600 W V lamp.

[0128] The effects of including increasing amounts of the zinc diacrylate in the curable composition are shown in Table 2.

TABLE-US-00002 TABLE 2 Strength at Young's Elongation at Energy at Composition break, psi Modulus, kpsi break, % break, ft-lb 1-A 2630 24.8 402 4.7 (Comparative) 1-B 2990 28.8 379 4.84 1-C 3020 31 335 4.53 1-D 2655 31.8 245 3.3

[0129] The inclusion of 10% by weight of the zinc diacrylate in the curable composition 1-B provided a significant increase in the tensile modulus and strength upon curing of the curable composition, in exchange for a slight decrease in elongation. The energy at break therefore increased, due to the presence of the zinc diacrylate. Since impact resistance is a measure of toughness and is directly correlated to energy at break, an increase in this property is therefore expected. Additionally, however, the inclusion of 10% of the zinc diacrylate has increased the reactivity of the formulation by increasing the number of ethylenically unsaturated sites present per mole of monomer and oligomer. This increase in reactivity helps the processing of formulations based on mono-functional monomers.