Radiation Curable Composition with Improved Mechanical Properties

Abstract

The present disclosure relates to a radiation or radiation/moisture dual curable compositions based on (meth)acrylate polymers or (meth)acrylate- and silane-terminated polymers. The invention further relates to their use as an adhesive, sealant and/or coating material, and adhesive, sealant and/or coating materials comprising said curable composition thereof.

Claims

1. A curable composition, comprising a) at least one first polymer A comprising at least one terminal group of the general formula (I)
-A.sup.1-C(═O)—CR.sup.1═CH.sub.2  (I), wherein A.sup.1 is a divalent bonding group containing at least one heteroatom; and R.sup.1 is selected from hydrogen and C.sub.1 to C.sub.4 alkyl; and, optionally, at least one terminal group of the general formula (II)
-A.sup.2-SiXYZ  (II), wherein A.sup.2 is a divalent bonding group containing at least one heteroatom; and X, Y, Z are each, independently of one another, selected from the group consisting of a hydroxyl group, C.sub.1 to C.sub.8 alkyl group, C.sub.1 to C.sub.8 alkoxy group, and C.sub.1 to C.sub.8 acyloxy group, wherein X, Y, Z are substituents directly bound with the Si atom or the two of the substituents X, Y, Z form a ring together with the Si atom to which they are bound, and at least one of the substituents X, Y, Z is selected from the group consisting of a hydroxyl group, C.sub.1 to C.sub.8 alkoxy group and C.sub.1 to C.sub.8 acyloxy group, b) optionally, at least one second polymer B comprising at least one terminal group of the general formula (II)
-A.sup.2-SiXYZ  (II), wherein A.sup.2 is a divalent bonding group containing at least one heteroatom; and X, Y, Z are each, independently of one another, selected from the group consisting of a hydroxyl group, C.sub.1 to C.sub.8 alkyl group, C.sub.1 to C.sub.8 alkoxy group, and C.sub.1 to C.sub.8 acyloxy group, wherein X, Y, Z are substituents directly bound with the Si atom or the two of the substituents X, Y, Z form a ring together with the Si atom to which they are bound, and at least one of the substituents X, Y, Z is selected from the group consisting of a hydroxyl group, C.sub.1 to C.sub.8 alkoxy and C.sub.1 to C.sub.8 acyloxy group, c) at least one reactive diluent, d) at least one photoinitiator, e) at least one filler, f) optionally, at least one adhesion promoter, and g) optionally, at least one curing catalyst.

2. The curable composition according to claim 1, wherein the polymer backbone of the at least one first polymer A and the optional at least one second polymer B are independently selected from the group consisting of polyoxyalkylene, poly(meth)acrylate, polyester, and combinations thereof.

3. The curable composition according to claim 1, wherein the polymer backbone of the at least one first polymer A and the optional at least one second polymer B are polyoxyalkylene.

4. The curable composition according to claim 1, wherein A.sup.1 and/or A.sup.2 comprises a substituted or unsubstituted ether, amide, carbamate, urethane, urea, imino, siloxane, carboxylate, carbamoyl, amidino, carbonate, sulfonate or sulfinate group.

5. The curable composition according to claim 1, wherein A.sup.1 and/or A.sup.2 comprise a urea and/or urethane group.

6. The curable composition according to claim 1, wherein in formula (II), X, Y, and Z are, independently of one another, selected from a hydroxyl, a methyl, an ethyl, a methoxy, or an ethoxy group, wherein at least one of the substituents is a hydroxyl group, or a methoxy or an ethoxy group.

7. The curable composition according to claim 1, wherein in formula (II), X, Y, and Z are, independently of one another, selected from a methoxy group or an ethoxy group.

8. The curable composition according to claim 1, wherein the total proportion of the terminal groups of the general formula (I) is 50 to 100 mol-%, and the total proportion of the terminal groups of the general formula (II) is 50 to 0 mol-%, wherein the proportion relates to the total amounts of the terminal groups of the general formulae (I) and (II) of the polymer A and the optional polymer B in the composition.

9. The curable composition according to claim 1, wherein the molar ratio of terminal groups of formula (I) to terminal groups of formula (II) is at least 2:1.

10. The curable composition according to claim 1, wherein said at least one polymer A comprises at least one terminal group of the general formula (II) and/or said composition comprises at least one second polymer B.

11. The curable composition according to claim 1, wherein the reactive diluent is selected from the group consisting of mono-functional (meth)acrylates, (meth)acrylamides, (meth)acrylic acid and combinations thereof.

12. The curable composition according to claim 1, wherein the reactive diluent is a monofunctional (meth)acrylate.

13. The curable composition according to claim 1, wherein the adhesion promoter is selected from silanes having the general formula (V)
B—R.sup.11—SiR.sup.12.sub.q(OR.sup.13).sub.3−q  (V), wherein R.sup.11 is an alkylene group, optionally interrupted by a heteroatom; each R.sup.12 is independently selected from the group consisting of a covalent bond, hydrogen, halogen, amino, a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloaliphatic, aryl, heteroaryl, and heteroalicyclic group or a combination thereof, each R.sup.13 is independently selected from the group consisting of a substituted or unsubstituted alkyl, alkenyl, alkynyl, or acyl group; B is a nitrogen-containing group selected from the general formula (1), (2), (3), (4), or (5) ##STR00003## wherein each R″ is independently selected from a covalent bond, hydrogen or a substituted or unsubstituted alkyl group; each R.sup.14, R.sup.14a, R.sup.14b, R.sup.14c, R.sup.15 and R.sup.16 is independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloaliphatic, aryl, heteroaryl, and heteroalicyclic group or a combination thereof; r is 1, 2, 3 or 4; R.sup.17 is —Si(R.sup.19).sub.3 and R.sup.18 is selected from —Si(R.sup.19).sub.3, hydrogen, a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloaliphatic, aryl, heteroaryl, and heteroalicyclic group or a combination thereof, or R.sup.17 and R.sup.18 can combine to form together with the nitrogen atom to which they are attached a group of formula —Si(R.sup.19).sub.2—R.sup.20—Si(R.sup.19).sub.2—, wherein each R.sup.19 is independently selected from hydrogen, a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloaliphatic, or aryl group or a combination thereof, and R.sup.20 is a linear or branched alkylene group; or the N atom from the group B of the general formula (1) and the Si atom in the general formula (V) which —(OR.sup.13) is attached to can combine to form a heterocyclic aminosilane structure, with one of the R.sup.12 group(s) being a covalent bond and one of the R″ groups being a covalent bond; and q is 0, 1, or 2.

14. The curable composition according to claim 1, wherein the adhesion promoter comprises at least one aminosilane selected from the group consisting of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, aminomethyltrimethoxysilane, aminomethyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, (N-2-aminoethyl)-3-aminopropyltrimethoxysilane, (N-2-aminoethyl)-3-aminopropyltriethoxysilane, diethylenetriaminopropyltrimethoxysilane, phenylaminomethyltrimethoxysilane, (N-2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-(N-phenylamino)propyl-trimethoxysilane, 3-piperazinylpropylmethyldimethoxysilane, 3-(N,N-dimethylaminopropyl)aminopropylmethyldimethoxysilane, tri[(3-triethoxysilyl)propyl]amine, tri[(3-trimethoxysilyl)propyl]amine, and the oligomers thereof, 3-(N,N-dimethylamino)propyltrimethoxysilane, 3-(N,N-dimethylamino)-propyltriethoxysilane, (N,N-dimethylamino)methyltrimethoxysilane, (N,N-dimethylamino)methyltriethoxysilane, 3-(N,N-diethylamino)propyltrimethoxysilane, 3-(N,N-diethylamino)propyltriethoxysilane, (N,N-diethylamino)methyltrimethoxysilane, (N,N-diethylamino)methyltriethoxysilane, bis(3-trimethoxysilyl)propylamine, bis(3-triethoxysilyl)propylamin, and mixtures thereof.

15. The curable composition according to claim 1, wherein the adhesion promoter comprises at least one aminosilane selected from the group consisting of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, aminomethyltrimethoxysilane, aminomethyltriethoxysilane, 3-(N,N-dimethylamino)propyltrimethoxysilane, 3-(N,N-dimethylam ino)propyltriethoxysilane, (N,N-dimethylamino)methyltrimethoxysilane, (N,N-dimethylamino)methyltriethoxysilane, 3-(N,N-diethylamino)propyltrimethoxysilane, 3-(N,N-diethylamino)propyltriethoxysilane, (N,N-diethylamino)methyltrimethoxysilane, (N,N-diethylamino)methyltriethoxysilane, bis(3-trimethoxysilyl)propylamine, bis(3-triethoxysilyl)propylamine, 4-amino-3,3-dimethylbuthyltrimethoxy silane, and 4-amino-3,3-dimethylbuthyltriethoxy silane.

16. The curable composition according to claim 1, wherein the adhesion promoter comprises at least one heterocyclic aminosilane having the general formula (V) with B being a group of the general formula (1), wherein the N atom from the group B of the general formula (1) and the Si atom in the general formula (V) which —(OR.sup.13) is attached to combine to form a heterocyclic aminosilane structure, with one of the R.sup.12 group(s) being a covalent bond and one of the R″ groups being a covalent bond.

17. The curable composition according to claim 1, wherein the adhesion promoter comprises N-alkyl-aza-2,2-dialkoxysilacycloalkanes, wherein alkyl is selected from methyl, ethyl, n-propyl, or n-butyl; alkoxy is selected from methoxy or ethoxy; and cycloalkane is selected from cyclopentane or cyclooctane.

18. The curable composition according to claim 1, wherein the composition further comprises one or more auxiliary substances, selected from plasticizer, light/UV stabilizer, drying agent, water scavenger, pigment, pigment paste, fungicide, flame retardant and/or solvent.

19. The curable composition according to claim 1, wherein the composition comprises, relative to the total weight of the composition, TABLE-US-00004 at least one polymer A and at least one optional   15-90 wt. %; polymer B at least one reactive diluent   1-70 wt. %; at least one photoinitiator 0.01-5 wt. %; at least one filler 0.01-60 wt. %; optionally, at least one adhesion promoter   0-5 wt. %; optionally, at least one curing catalyst   0-5 wt. %; and optionally, one or more auxiliary substance(s)   0-70 wt. %; wherein the proportions by weight add up to 100 wt. % and the proportions by weight are based on the total weight of the curable composition.

20. An adhesive, sealant and/or coating material comprising a curable composition according to claim 1.

Description

EXAMPLES

Example 1: Radiation Curable Compositions

Preparation of Polymer 1

[0197] In a first step, 94.5 wt.-% of polypropylene oxide (PPG 12000), 3.5 wt.-% of isophorone diisocyanate (IPDI) and 0.2 wt.-% of dioctyl tin dilaurate (DOTL) were mixed for 0.5 hours at 80° C. under nitrogen at 400U/minute. The molar ratio of OH groups to NCO groups was 1:2. After the reaction, the reaction mixture was allowed to cool to 25° C. and then 1.9 wt.-% of hydroxy ethyl methacrylate (HEMA) was added (in an amount that corresponds to a molar ratio of OH(from polyol):NCO:OH(from HEMA) of 1:2:0.95). Mixing was carried out for 24 hours at 25° C. Methacrylate-terminated polymer (Polymer 1 with M.sub.w of 55,000 g/mol determined by gel permeation chromatography (GPC) with tetrahydrofuran (THF) as the eluent according to DIN 55672-1:2007-08 and a viscosity of 145,000 mPas (Anton Paar, Physica MCR 301 at 23° C., Spindle PP25) was obtained.

Preparation of Formulations 1-A to 1-D (1-A to 1-D)

[0198] The obtained Polymer 1 was used in various formulations. All amounts given are in wt.-% relative to the total weight of the composition. All formulations were tack-free after curing with UV light. Mechanical properties of the UV curable formulations were measured and the results are shown in Table 1 below.

TABLE-US-00002 TABLE 1 (all amounts in wt.-%) 1-A 1-B 1-C 1-D Polymer 1 54.3 51.6 40.73 27.15 Tinuvin 328 0.44 0.44 0.44 0.44 Viscoexcel 30 SG 39.8 39.8 39.8 39.8 (fatty acid modified chalk filler) HDK H18 (fumed silica) 4.5 4.5 4.5 4.5 Isobornyl acrylate 0 2.7 13.57 27.15 Omnirad TPO-L 0.96 0.96 0.96 0.96 Total 100 100 100 100 Tear strength [N/mm] 13.8 14.5 18.4 29.8 Tensile strength [N/mm.sup.2] 4.8 6 7.7 8.6 Elongation at break [%] 530 585 676 380

Example 2: Radiation and Moisture Dual Curable Compositions

Preparation of Polymer 2

[0199] In a first step, 72.8 wt.-% of polypropylene oxide (PPG 2000), 16.2 wt.-% of isophorone diisocyanate (IPDI) and 0.07 wt.-% of dioctyl tin dilaurate (DOTL) were mixed for 0.5 hours at 80° C. under nitrogen at 400U/minute. The molar ratio of OH groups to NCO groups was 1:2. After the reaction, the reaction mixture was allowed to cool to 25° C. and then 6.5 wt.-% of aminopropyl trimethoxysilane (AMMO) was added, and 0.5 hours later 4.5 wt.-% of hydroxy ethyl methacrylate (HEMA) was added (in an amount that corresponds to a molar ratio of OH(from polyol):NCO:NH.sub.2(from AMMO):OH(acrylate from HEMA) of 1:2:0.5:0.48). Mixing was carried out for 4.5 hours at 25° C. The mixture of methacrylate-terminated polymer, silane-terminated polymer, and methacrylate- and silane-terminated polymer (Polymer 2 with M.sub.w of 7400 g/mol determined by gel permeation chromatography (GPC) with tetrahydrofuran (THF) as the eluent according to DIN 55672-1:2007-08 and a viscosity of 68,000 mPas (Anton Paar, Physica MCR 301 at 23 ° C., Spindle PP25) was obtained.

Preparation of Formulations 2-A to 2-E (2-A to 2-E)

[0200] In addition to Formulation 1-C prepared in Example 1, the obtained Polymer 2, at least one adhesion promoter, and a curing catalyst were added in various formulations. All formulations were tack-free after curing with UV light. Mechanical properties of the UV and moisture dual curable formulations were measured and the results are shown in Table 2 below.

TABLE-US-00003 TABLE 2 (all amounts in parts by weight) 2-A 2-B 2-C 2-D 2-E Formulation 1-C 95 95 95 95 95 Polymer 2 5 5 5 5 5 N-n-butyl-aza-2,2- 0 1 0 1 0 dimethoxysilacyclopentane Aminopropyltrimethoxysilane 0 0 1 0 1 dioctyl tin dilaurate (DOTL) 0 0 0 0.2 0.2 Tear strength [N/mm] 18 9.1 9.7 9.3 10.3 Tensile strength [N/mm.sup.2] 8.3 6.1 6.2 6.4 6.4 Elongation at break [%] 704 594 510 551 488 Shear resistance [N/mm.sup.2] directly after curing (% ratio compared to the shear resistance of 2-A) PMMA-Stainless steel 0.9 0.6 (67%) 0.7 (78%) 0.7 (78%) 0.9 (100%) PMMA-Aluminium 1.1 0.8 (73%) 0.8 (73%)  1.1 (100%) 1.1 (100%) PMMA-Glass 0.9 0.6 (67%) 0.6 (67%)  0.9 (100%) 1.1 (122%) PMMA-PC 0.9  0.9 (100%) 0.7 (78%)  1.3 (144%) 1.4 (156%) PMMA-PVC 1.0 0.7 (70%) 0.9 (90%)  1.1 (110%) 1.2 (120%) PMMA-PMMA 1.1 1.0 (91%)  1.3 (118%)  1.2 (109%) 1.4 (127%) Shear resistance [N/mm.sup.2]7 d after curing (% ratio compared to the shear resistance of 2-A) PMMA-Stainless steel 1.1 1.2 (109%) 2.6 (236%) 1.1 (100%) 1.2 (109%) PMMA-Aluminium 1.1 1.5 (136%) 2.7 (245%) 1.3 (118%) 1.8 (164%) PMMA-Glass 0.8 2.2 (275%) 2.4 (300%) 1.6 (200%) 1.9 (238%) PMMA-PC 1.1 1.9 (173%) 2.1 (191%) 1.5 (136%) 2.2 (200%) PMMA-PVC 1.4 1.5 (107%) 2.1 (150%) 1.6 (114%) 1.8 (129%) PMMA-PMMA 1.4 3.4 (243%) 2.7 (193%) 2.4 (171%) 2.4 (171%) PMMA: poly(methylmethacrylate) substrate PC: polycarbonate substrate PVC: polyvinyl chloride substrate

Measurement Methods

[0201] Tear strength was determined in accordance with DIN ISO 34-1 2004-07. The samples were cure in a mold with 1 side open in a UV Curing chamber with 100% intensity for 1 min first, and then the samples were turned around and cured for 1 min on the other side.

[0202] Tensile strength and elongation at break were determined in accordance with DIN 53504. The samples were cure in a mold with 1 side open in a UV Curing chamber with 100% intensity for 1 min first, and then the samples were turned around and cured for 1 min on the other side. The specimen type S3 (Dog bone) was used and the speed of the pull head in the dynamometer was 500 mm/min.

[0203] Shear resistance was determined in accordance with DIN EN 1465. The samples were exposed to UV radiation for 1 min through the PMMA side which is transparent.