CROSSLINKABLE COMPOSITIONS HAVING A LOW VISCOSITY FOR COATINGS AND MATERIALS HAVING A HIGH REFRACTIVE INDEX AND HAVING A HIGH HEAT DEFLECTION TEMPERATURE

Abstract

The invention relates to a crosslinkable composition, which comprises a component a) at least one halogenated bisphenol A diglycidyl ether tetra(meth)acrylate and a component b) at least one diluent from mono(meth)acrylates of a monoalcohol comprising a biphenyl structure, and at least one optional component from components c), d), e), f) and g). It also relates to its use for coatings or materials, in particular for 3D printed articles for optical applications, as it also relates to the crosslinked composition and to the finished product, in particular the 3D article which results therefrom.

Claims

1. Crosslinkable composition comprising as component a) at least one halogenated bisphenol A diglycidyl ether tetra(meth)acrylate and as component b) at least one diluent from mono(meth)acrylates of a monoalcohol comprising a biphenyl structure, said biphenyl optionally being halogenated, and optionally at least one component chosen from components c), d), e), f) and g) as defined as follows: c) at least one (meth)acrylated oligomer carrying at least 4 (meth)acrylate functional groups per chain, said oligomer comprising at least 2 units of halogenated bisphenol A structure in the chain of said oligomer, d) at least one di(meth)acrylate of an epoxidized biphenyl derivative, said biphenyl derivative optionally being halogenated, e) an optionally halogenated bisphenol A diglycidyl ether di(meth)acrylate, f) at least one monomer other than a), b), d) and e), g) at least one oligomer from urethane (meth)acrylate, polyester (meth)acrylate and polyether (meth)acrylate.

2. Composition according to claim 1, wherein said composition comprises component c) and said oligomer as defined according to c) comprises 2 units of halogenated bisphenol A structure in the chain of said oligomer.

3. Composition according to claim 1, wherein said composition comprises component d) and component d) is 2-biphenylyl glycidyl ether di(meth)acrylate.

4. Composition according to claim 1, wherein said composition comprises component f) and said monomer as defined according to f) has a functionality of (meth)acrylates ranging from 1 to 6 and is selected from mono(meth)acrylic esters of C1 to C18 aliphatic alcohols or of C6 to C18 cycloaliphatic alcohols or from polyfunctional (meth)acrylic esters (of functionality 2 to 6) of C2 to C18 polyols, and optionally said monomer f) comprises at least one unit of alkoxy structure.

5. Composition according to claim 1, wherein said composition comprises component f) and said monomer as defined according to f) comprises one or more alkoxy units, optionally chosen from ethoxy, propoxy or butoxy or from mixtures thereof.

6. Composition according to claim 1, wherein said composition comprises component g) and said at least one oligomer of component g) has a (meth)acrylate functionality ranging from 1 to 15.

7. Composition according to claim 1, wherein said halogenated or optionally halogenated components comprise a halogen selected from bromine, chlorine and fluorine.

8. Composition according to claim 1, wherein said halogenated or optionally halogenated compounds have a number of hydrogen atoms of the aromatic nucleus of said halogenated or optionally halogenated compound, replaced by a halogen, which varies from 1 to 2 per aromatic nucleus of said halogenated or optionally halogenated component.

9. Composition according to claim 1, wherein said component a) is tetrabrominated bisphenol A diglycidyl ether tetramethacrylate of following formula (I): ##STR00007##

10. Composition according to claim 1, wherein the component b) is biphenylmethanol mono(meth)acrylate of following formula (II): ##STR00008## with R being methyl or H.

11. Composition according to claim 1, wherein said oligomer as defined according to c) is of following formula (III): ##STR00009##

12. Composition according to claim 1, wherein said monomer d) is 2-biphenylyl glycidyl ether dimethacrylate as defined according to the following formula (IVc): ##STR00010##

13. Composition according to claim 1, wherein the content by weight of the component a), with respect to the weight a)+b), varies from 20% to 80%.

14. Composition according to claim 1, wherein the content by weight of the component c), with respect to the weight a)+b), varies from 0% to 50%.

15. Composition according to claim 1, wherein the content by weight of the component d), with respect to the weight a)+b), varies from 0% to 50%.

16. Composition according to claim 1, wherein the content by weight of the component e), with respect to the weight a)+b), varies from 0% to 50%.

17. Composition according to claim 1, wherein the content by weight of f), with respect to the weight a)+b), varies from 0% to 50%.

18. Composition according to claim 1, wherein the content by weight of g), with respect to the weight a)+b), varies from 0% to 40%.

19. Composition according to claim 1, further comprising at least one initiator.

20. Composition according to claim 19, wherein said initiator is selected from a peroxide or a hydroperoxide.

21. Composition according to claim 19, initiator is at least one photoinitiator.

22. (canceled)

23. (canceled)

24. Composition according to claim 1, wherein said composition has a viscosity at 25° C. according to the ISO 3219 (1993) method of less than 5000 mPa.Math.s.

25. (canceled)

26. (canceled)

27. Composition according to claim 1, wherein said composition has an RI before crosslinking according to the ASTM 1218-02 standard of at least 1.47 and, after crosslinking, of at least 1.50.

28. A method of using a composition according to claim 1 as a coating having at least one of an HDT according to the ISO 75 (2004) method of at least 70° C. and an RI of at least 1.50 comprising curing the composition to form the coating.

29. (canceled)

30. A method of using a composition according to claim 1, comprising curing the composition to form a 3D printed article.

31. (canceled)

32. A 3D printed made by the method of claim 30 having a refractive index RI of at least 1.50.

33. (canceled)

34. (canceled)

35. (canceled)

36. (canceled)

37. (canceled)

Description

EXAMPLES

1) Formulations

[0095] The compositions of the formulations tested according to Examples 1 to 5 are presented in Table 1 below starting from the following components:
Compound A: SR833S, Sartomer, tricyclodecanedimethanol diacrylate
Compound B: tetrabromo bisphenol A diglycidyl ether dimethacrylate
Compound C: tetrabromo bisphenol A diglycidyl ether tetramethacrylate
Compound D: biphenyl glycidyl ether dimethacrylate
Compound E: SR348L from Sartomer, bisphenol A ethoxylate (2) dimethacrylate
Compound F: HPMA from Evonik, hydroxypropyl methacrylate
Compound G: H008 from KPX Green Chemical, biphenylmethanol acrylate

TABLE-US-00001 TABLE 1 Compositions of the formulations tested of Examples 1 to 5 Component Example 1 Example 2 Example 3 Example 4 Example 5 A 14.0 / / 13.30 / B 27.0 12.50 13.20 25.65 / C 27.0 29.25 30.85 25.65 42.75 D / / / / 23.75 E / 16.75 17.70 / / F / 10.0 5.0 5.0 5.0 G 32.0 31.5 33.25 30.40 28.50 Total: 100.0 100.0 100.0 100.0 100.0

2) Characteristics of the Liquid Formulations Before Crosslinking

[0096] These characteristics are presented in Table 2 below.

TABLE-US-00002 TABLE 2 Characteristics of the formulations tested of Examples 1 to 5 Example 1 Example 2 Example 3 Example 4 Example 5 Refractive 1.578 1.565 1.572 1.570 1.575 index Brookfield 3200 750 1440 1880 1150 viscosity @ 25° C. (mPa .Math. s) Colouration 1.6 1.3 1.2 1.5 1.2 (Gardner)
3) Physicochemical Characteristics after Crosslinking

Samples

[0097] The samples are prepared starting from silicone moulds. The bars (DMA, HDT, 3-point bending) have the dimensions, in mm, of 80*10*4 and the test specimens of 5A type for the tensile testing have a thickness of 4 mm. The photoinitiator system is TPO-L, 2% for all the formulae, and the crosslinking is carried out under 100% UV bench LED strip, followed by a postcuring at 80° C. for 12 hours.

Analytical Conditions:

[0098] Tests carried out at 23° C. under a relative humidity of 50%.

[0099] DMA Analysis:

The DMA analysis is carried out on an RDAIII device (Rheometrics), in rectangular torsion, with a sweep from −50° C. to 200° C., at 3° C./min, and a nominal strain of 0.05% and with a frequency of 1 Hz.

[0100] HDT (Standard ISO 75 of 2004):

The HDT (Heat Deflection Temperature) tests are carried out on the HDT device (EDIT). Method A is used (1.8 MPa); the test specimen (thickness of 4 mm) is positioned flat on the substrate (distance between supports=64 mm). The heating rate is 120° C./h.

[0101] Tensile Test:

The tensile tests are carried out on an MTS tensile testing device, 500 N cell. The test specimens used are of 5A type. The pull rate is 1 mm/min and then 10 mm/min starting from 7% elongation.

[0102] 3-Point Bending (Standard ISO 178 of 2001)

The 3-point bending tests are carried out on an MTS tensile testing device in 3-point bending mode, the distance between supports of which is 16×the mean thickness of the batch. The test rate is 1 mm/min.

Results

[0103] The results of the performance qualities of the formulations tested of Examples 1 to 5 are presented in Table 3 below.

TABLE-US-00003 TABLEAU 3 Performance qualities of the formulations tested of Examples 1 to 5 Example 1 Example 2 Example 3 Example 4 Example 5 DMA (° C.) 121 114 119 118 114 HDT (° C.) 86 93 86 95 94 Tensile testing Stress (MPa) 31.3 +/− 3.5  30 +/− 6  30 +/− 6  30 +/− 8  25 +/− 8  Elongation at break 1.5 +/− 0.1 1.6 +/− 0.5 1.7 +/− 0.5 1.4 +/− 0.5 1.1 +/− 0.3 (%) Modulus (MPa) 2800 +/− 170  3100 +/− 160  3300 +/− 200  3000 +/− 150  2800 +/− 140  3-Point bending Stress (MPa)  79 +/− 0.4 91 +/− 1  81 +/− 10 82 +/− 11 55 +/− 18 Deflection at break 3.7 +/− 0.2 5.1 +/− 0.1 4.3 +/− 0.6 4.2 +/− 0.5 2.1 +/− 0.7 (mm) Modulus (MPa) 3775 +/− 64  3527 +/− 150  3474 +/− 118  3494 +/− 143  4100 +/− 100