Photopolymerizable dental composites with rapid curing and low shrinkage stress

1. A radically polymerizable material consisting of

(a) 0.01 to 5 wt.-% of at least one transfer reagent,

(b) 10 to 40 wt.-% of at least one multifunctional (meth)acrylate selected from bi-sphenol A dimethacrylate, bis-GMA (an addition product of methacrylic acid and bisphenol A diglycidyl ether), 2-[4-(2-(meth)acryloyloxyethoxyethoxy)phenyl]-2-[4-(2-methacryloyloxy-ethoxy)phenyl]propane), 2,2-bis[4-(2-methacryloxypropoxy)phenyl]propane (bis-PMA), UDMA (an addition product of 2-hydroxyethyl methacrylate and 2,2,4- or 2,4,4-trimethylhexa-methylene-1,6-diisocyanate), bismethacryloyloxymethyltricyclo[5.2.1.]decane (TCDMA) and mixtures thereof,

(c) 0.01 to 2.0 wt.-% of a mixture of

at least one monomolecular photoinitiator selected from a diacyldialkylgermanium, tetraacylgermanium and tetraacylstannane compound, a mono- or bisacylphosphine oxide or a mixture thereof, and

at least one bimolecular photoinitiator selected from camphorquinone (CQ), 9,10-phenanthrenequinone, 1-phenylpropane-1,2-dione, 2,2-dimethoxy-2-phenylacetophenone, diacetyl, 4,4′-dichlorobenzil or a combination of at least one of camphorquinone (CQ), 9,10-phenanthrenequinone, 1-phenylpropane-1,2-dione, 2,2-dimethoxy-2-phenylacetophenone, diacetyl, 4,4′-dichlorobenzil with an amine selected from with 4-(dimethylamino)-benzoic acid ester (EDMAB), N,N-dimethylaminoethyl methacrylate, N,N-dimethyl-sym.-xylidine, triethanolamine or a mixture thereof,

(d) 50 to 85 wt.-% of at least one filler selected from mixed oxides of SiO 2 and ZrO 2 , glass powders, radiopaque fillers, ground prepolymers and mixtures thereof, and

(e) 0 to 3 wt.-% additive(s), in each case relative to the total mass of the material,

wherein the material comprises as transfer reagent (a) at least one allyl sulfone of Formula I

in which the variables have the following meanings:

A H; —CN; a phenyl radical, which can bear one or more substituents, such as —CH 3 , —C 2 H 5 , —OH, —OCH 3 , —O—COCH 3 , a polymerizable vinyl, (meth)acryloyloxy or (meth)acrylamide group, or an aliphatic linear or branched C 1 —C 20 alkylene or C 1 —C 20 alkyl radical, which can be interrupted by one or more 1,4-phenylene groups, urethane groups, O or S, which can bear one or more substituents, such as —OH or —OCH 3 , and which can bear a tri-C 1 -C 4 alkoxysilyl group or a polymerizable vinyl, (meth)acryloyloxy or (meth)acrylamide group terminally;

R 1 in each case independently of one another H, an aliphatic linear or branched C 1 -C 9 alkyl radical, tolyl or phenyl;

R 2 in each case independently of one another a phenyl radical, which can bear one or more substituents, such as —CH 3 , —C 2 H 5 , —OH, —OCH 3 , —O—COCH 3 , a polymerizable vinyl, (meth)acryloyloxy or (meth)acrylamide group, —C(═CH 2 )—COOR 3 or —C(═CH 2 )—CO—NR 4 R 5 ; or an aliphatic linear or branched C 1 —C 20 alkyl radical, which can be interrupted by O or S and which can bear a polymerizable vinyl, (meth)acryloyloxy or (meth)acrylamide group, —C(═CH 2 )—COOR 3 or —C(═CH 2 )—CO—NR 4 R 5 terminally, wherein R 3-5 independently of one another are in each case a linear or branched C 1-6 alkyl radical;

X —COO—, —CON(R 6 )— or is absent, wherein the bonding to A is effected via O or N and wherein

R 6 is H; or an aliphatic linear or branched C 1 -C 20 alkyl radical, which can be interrupted by one or more O or S and which can bear a polymerizable vinyl, (meth)acryloyloxy or (meth)acrylamide group, —C(═CH 2 )—COOR 3 or —C(═CH 2 )—CO—NR 4 R 5 terminally, wherein R 3-5 independently of one another are in each case a linear or branched C 1-6 alkyl radical;

n an integer from 1 to 6,

and/or

a vinyl sulfone ester of Formula II,

in which the variables have the following meanings:

B H, CN, a cycloaliphatic, linear or branched aliphatic C 1 -C 30 hydrocarbon radical, which can be substituted by one or more substituents, which can be interrupted by one or more urethane groups, ester groups, O and/or S and which can contain 1 to 4 benzene groups,

an aromatic C 6 -C 30 hydrocarbon radical, which can be substituted by one or more substituents;

Y —COO—, —CON(R 7 )— or is absent, wherein the bonding to B is effected via O or N;

C a cycloaliphatic, linear or branched aliphatic C 1 -C 30 hydrocarbon radical, which can be substituted by one or more substituents, which can be interrupted by one or more urethane groups, ester groups, O and/or S and which can contain 1 to 4 benzene groups,

an aromatic C 6 -C 30 hydrocarbon radical, which can be substituted by one or more substituents;

R 7 hydrogen, a cycloaliphatic, linear or branched aliphatic C 1 -C 10 hydrocarbon radical, which can be interrupted by one or more oxygen atoms and which can be substituted by one or more OH groups, or

an aromatic C 6 -C 10 hydrocarbon radical, which can be substituted by one or more OH groups;

p an integer from 1 to 6;

k an integer from 1 to 6;

q an integer from 1 to 6; wherein

p and q cannot be greater than 1 at the same time and wherein if p=1, q=k, and if q=1, p=k.

2. The material according to claim 1 , in which the variables have the following meanings:

B H, CN, a cycloaliphatic, linear or branched aliphatic C 1 -C 30 hydrocarbon radical, which can be substituted by 1 to 6 or 1 to 3 substituents comprising —CH 3 , —C 2 H 5 , —OH, —OCH 3 and/or —O—COCH 3 , which can be interrupted by 1 to 4, or 1 to 2 urethane groups, ester groups, O and/or S and which can contain 1 or 2 benzene groups, an aromatic C 6 -C 30 hydrocarbon radical, which can be substituted by 1 to 6, or 1 to 3 substituents comprising —CH 3 , —C 2 H 5 , —OH, —OCH 3 and/or —O—COCH 3 , or a combination thereof;

C a cycloaliphatic, linear or branched aliphatic C 1 -C 30 hydrocarbon radical, which can be substituted by 1 to 6 or 1 to 3 substituents comprising C 1 -C 5 alkyl, —OH, —O—COCH 3 and/or C 1 -C 5 alkoxy, which can be interrupted by 1 to 4 or 1 to 2 urethane groups, ester groups, O and/or S and which can contain 1 or 2 benzene groups, an aromatic C 6 -C 30 hydrocarbon radical, which can be substituted by 1 to 6 or 1 to 3 substituents comprising vinyl, C 1 -C 5 alkyl, —OH, —O—COCH 3 and/or C 1 -C 5 alkoxy, or tosyl, or a combination thereof;

R 7 hydrogen, a cycloaliphatic, linear or branched aliphatic C 1 -C 10 hydrocarbon radical, which can be interrupted by 1 to 4 or 1 to 2 oxygen atoms and which can be substituted by 1 to 4 or 1 to 2 OH groups, or an aromatic C 6 -C 10 hydrocarbon radical, which can be substituted by 1 to 4 or 1 to 2 OH groups.

3. The material according to claim 1 , in which the variables of Formula I have the following meanings:

A H; an aliphatic linear or branched C 1 -C 14 alkylene or C 1 -C 14 alkyl radical, which can be interrupted by one or more O or S, which can bear one or more substituents, such as —OH or —OCH 3 , and which can bear a tri-C 1 -C 3 alkoxysilyl group or a polymerizable vinyl, (meth)acryloyloxy or (meth)acrylamide group terminally;

R 1 H, an aliphatic branched or linear C 1 -C 4 alkyl radical, tolyl or phenyl;

R 2 in each case independently of one another a phenyl radical, which can bear one or more substituents, such as —CH 3 , —C 2 H 5 , —OH, —OCH 3 , —O—COCH 3 ; or an aliphatic linear or branched C 1 -C 10 alkyl radical, which can be interrupted by O or S;

X —COO—, —CON(R 6 )— or is absent, wherein the bonding to A is effected via O or N and wherein

R 6 H; or an aliphatic linear or branched C 1 -C 10 alkyl radical, which can be interrupted by one or more O or S;

n an integer from 1 to 3,

and/or

in which the variables of Formula II have the following meanings:

B H, a cycloaliphatic, linear or branched aliphatic C 1 -C 15 hydrocarbon radical, which can be substituted by 1 to 4 or 1 to 3 substituents comprising —CH 3 , —C 2 H 5 , —OH, —OCH 3 and/or —O—COCH 3 , which can be interrupted by 1 to 4 or 1 to 2 urethane groups, ester groups, O and/or S and which can contain 1 or 2 benzene groups,

an aromatic C 6 -C 18 hydrocarbon radical, which can be substituted by 1 to 6 or 1 to 3 substituents comprising —CH 3 , —C 2 H 5 , —OH, —OCH 3 and/or —O—COCH 3 , or a combination thereof;

Y —COO—, —CON(R 7 )— or is absent, wherein the bonding to B is effected via O or N;

C a cycloaliphatic, linear or branched aliphatic C 1 -C 15 hydrocarbon radical, which can be substituted by 1 to 4 or 1 to 3 substituents comprising C 1 -C 4 alkyl, —OH, —O—COCH 3 and/or C 1 -C 4 alkoxy, which can be interrupted by 1 to 4 or 1 to 2 urethane groups, ester groups, O and/or S and which can contain 1 or 2 benzene groups,

an aromatic C 6 -C 18 hydrocarbon radical, which can be substituted by 1 to 6 or 1 to 3 substituents comprising vinyl, C 1 -C 4 alkyl, —OH, —O—COCH 3 and/or C 1 -C 4 alkoxy, or tosyl, or a combination thereof;

R 7 hydrogen, a cycloaliphatic, linear or branched aliphatic C 1 -C 6 hydrocarbon radical, which can be interrupted by one or more or 1 to 2 oxygen atoms and which can be substituted by one or more or 1 to 2 OH groups, or an aromatic C 6 -C 10 hydrocarbon radical, which can be substituted by one or more or 1 to 2 OH groups;

p an integer from 1 to 3;

k an integer from 1 to 3;

q an integer from 1 to 3; wherein

p and q cannot be greater than 1 at the same time and wherein if p=1, q=k, and if q=1, p=k.

4. The material according to claim 1 , wherein the at least one transfer reagent (a) according to Formula I is selected from 2-(toluene-4-sulfonylmethyl)-acrylic acid ethyl ester (TSMEA), 2-(toluene-4-sulfonylmethyl)-acrylic acid 2-(2-ethoxyethoxy)-ethylester, 2-(toluene-4-sulfonylmethyl)-acrylic acid, 2-(toluene-4-sulfonylmethyl)-acrylic acid tert-butyl ester, 3-(trimethoxysilyl)propyl-2-(tosylmethyl) acrylate, 3-(triethoxysilyl)propyl-2-(tosylmethyl) acrylate, 3-(triethoxysilyl)propyl-2-(tosylmethyl)acrylamide, 2-(methylsulfonylmethyl)-ethyl acrylate, 2-(methylsulfonylmethyl)-propyl acrylate, triethylene glycol bis[2-(toluene-4-sulfonylmethyl) acrylate], 2-(toluene-4-sulfonylmethyl)-acrylic acid (2-methacryloyloxyethyl) ester, 2-(toluene-4-sulfonylmethyl)-acrylic acid (6-methacryloyloxyhexyl) ester, 2-(toluene-4-sulfonylmethyl)-acrylic acid (10-methacryloyloxydecyl) ester, 2-(toluene-4-sulfonylmethyl)-acrylic acid (2-hydroxy-3-methacryloyloxypropyl) ester, 2-(toluene-4-sulfonylmethyl)-acrylic acid (8-methacryloyloxy-3,6-dioxaoctyl) ester, or 2-(toluene-4-sulfonylmethyl)-acrylic acid ethyl ester (TSMEA),

and/or

wherein the at least one transfer reagent (a) according to Formula II is selected from 2-(toluene-4-sulfonyloxy)-acrylic acid ethyl ester (TSVEA), 2-methanesulfonyloxyacrylic acid ethyl ester, triethylene glycol bis[2-(toluene-4-sulfonyloxy) acrylate], 2-(2,4,6-triisopropylbenzenesulfonyloxyacrylic acid octyl ester, 2-(toluene-4-sulfonyloxy)-acrylic acid 2-(tetrahydropyran-2-yloxy)-ethyl ester, 2-(toluene-4-sulfonyloxy)-acrylic acid 2-hydroxyethyl ester, 2-(toluene-4-sulfonyloxy)-acrylic acid 2,4,6-trimethylphenyl ester, 2-(4-vinylbenzenesulfonyloxy)-acrylic acid ethyl ester, 2-(toluene-4-sulfonyloxy)-acrylic acid methoxymethyl ester, 2-(2,4,6-triisopropylbenzenesulfonyloxy)-acrylic acid methoxymethyl ester, 2-(2,4,6-triisopropylbenzenesulfonyloxy)-acrylic acid, diethyl-2,2′-[(1,3-phenyldisulfonyl)bis(oxy)] diacrylate, or 2-(toluene-4-sulfonyloxy)-acrylic acid ethyl ester (TSVEA).

5. The material according to claim 1 , in which the at least one monomolecular photoinitiator and the at least one bimolecular photoinitiator are used in a weight ratio of from 2:1 to 1:2, or from 1.4:1 to 1:2 or from 1.2:1 to 1:1.8 or from 1:1 to 1:1.8.

6. The material according to claim 1 , in which the bimolecular photoinitiator and the amine are used in a weight ratio of from 1:1 to 1:6.

7. The material according to claim 1 , wherein the at least one filler (d) is selected from a mixed oxide of SiO 2 and ZrO 2 , a glass powder comprising barium or strontium aluminium silicate glass powder, a radiopaque filler comprising ytterbium trifluoride or a mixed oxide of SiO 2 with ytterbium(III) oxide, a ground prepolymer or a mixture thereof.

8. The material according to claim 1 , which consists of

(a) 0.1 to 5 wt.-% of at least one transfer reagent of Formula(e) I and/or II,

(b) 10 to 40 wt.-% of at least one multifunctional (meth)acrylate selected from bisphenol A dimethacrylate, bis-GMA (an addition product of methacrylic acid and bisphenol A diglycidyl ether), 2-[4-(2-(meth)acryloyloxyethoxyethoxy)phenyl]-2-[4-(2-methacryloyloxyethoxy)phenyl]propane), 2,2-bis[4-(2-methacryloxypropoxy)phenyl]propane (bis-PMA), UDMA (an addition product of 2-hydroxyethyl methacrylate and 2,2,4- or 2,4,4-trimethylhexamethylene-1,6-diisocyanate), bismuthacryloyloxymethyltricyclo[5.2.1.]decane (TCDMA) and mixtures thereof,

(c) 0.1 to 2.0 wt.-% of a mixture of a diacyldialkylgermanium compound with camphorquinone (CQ) and 4-(dimethylamino)-benzoic acid ester (EDMAB),

(d) 50 to 85 wt.-% filler selected from mixed oxides of SiO 2 and ZrO 2 , barium or strontium aluminium silicate glass powders, ytterbium trifluoride, mixed oxides of SiO 2 with ytterbium(III) oxide, ground prepolymers and mixtures thereof, and

(e) 0.2 to 3 wt.-% additive(s),

in each case relative to the total mass of the material.

9. The material according to claim 1 , which consists of

(a) 0.1 to 3 wt.-% of at least one transfer reagent of Formula(e) I and/or II,

(b) 10 to 40 wt.-% of at least one multifunctional (meth)acrylate selected from bisphenol A dimethacrylate, bis-GMA (an addition product of methacrylic acid and bisphenol A diglycidyl ether), 2-[4-(2-(meth)acryloyloxyethoxyethoxy)phenyl]-2-[4-(2-methacryloyloxyethoxy)phenyl]propane), 2,2-bis[4-(2-meth-acryloxypropoxy)phenyl]propane (bis-PMA), UDMA (an addition product of 2-hydroxyethyl methacrylate and 2,2,4- or 2,4,4-trimethylhexamethylene-1,6-diisocyanate), bismuthacryloyloxymethyltricyclo[5.2.1.]decane (TCDMA) and mixtures thereof,

(c) 0.1 to 2.0 wt.-% of a mixture of a diacyldialkylgermanium, tetraacylgermanium and/or tetraacylstannane compound or of a mono- or bisacylphosphine oxide with a camphorquinone (CQ) and/or 2,2-dimethoxy-2-phenylacetophenone, as well as with 4-(dimethylamino)-benzoic acid ester (EDMAB),

(d) 50 to 85 wt.-% filler selected from mixed oxides of SiO 2 and ZrO 2 , glass powders, radiopaque fillers, ground prepolymers and mixtures thereof, and

(e) 0.2 to 3 wt.-% additive(s),

in each case relative to the total mass of the material.

10. The material according to claim 1 for intraoral use for the restoration of damaged teeth or for intraoral use as dental cement, filling composite or veneering material.

11. The material according to claim 1 , wherein the one or more additives are selected from stabilizers, colorants, microbiocidal active ingredients, fluoride-ion-releasing additives, blowing agents, optical brighteners, plasticizers and UV absorbers.

12. The material according to claim 1 , wherein

the at least one monomolecular photoinitiator is selected from 2,4,6-trimethylbenzoyl diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl) phenylphosphine oxide, dibenzoyldiethyl-germane, bis(4-methoxybenzoyl)diethylgermane (MBDEGe), tetrabenzoylgermane, tetrakis(o-methylbenzoyl)germane, tetrakis (mesitoyl) stannane or a mixture thereof, and

the at least one bimolecular photoinitiator is selected from camphorquinone (CQ), 2,2-dimethoxy-2-phenylacetophenone or a mixture thereof; or a combination of camphorquinone (CQ), 2,2-dimethoxy-2-phenylacetophenone or a mixture thereof with an amine selected from with 4-(dimethylamino)-benzoic acid ester (EDMAB), N,N-dimethylaminoethyl methacrylate, N,N-dimethyl-sym.-xylidine, triethanolamine or a mixture thereof.

13. The material according to claim 12 , wherein the one or more additives are selected from stabilizers, colorants, microbiocidal active ingredients, fluoride-ion-releasing additives, blowing agents, optical brighteners, plasticizers and UV absorbers.

14. The material according to claim 1 , wherein

the at least one monomolecular photoinitiator is selected from 2,4,6-trimethylbenzoyl diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl) phenylphosphine oxide, dibenzoyldiethyl-germane, bis(4-methoxybenzoyl)diethylgermane (MBDEGe), tetrabenzoylgermane, tetrakis(o-methylbenzoyl)germane, tetrakis (mesitoyl) stannane or a mixture thereof, and

the at least one bimolecular photoinitiator is selected from camphorquinone (CQ), 2,2-dimethoxy-2-phenylacetophenone or a mixture thereof; or a combination of camphorquinone (CQ), 2,2-dimethoxy-2-phenylacetophenone or a mixture thereof with 4-(dimethylamino)-benzoic acid ester (EDMAB).

15. The material accordign to claim 14 , wherein the one or more additives are selected from stabilizers, colorants, microbiocidal active ingredients, fluoride-ion-releasing additives, blowing agents, optical brighteners, plasticizers and UV absorbers.

16. The material according to claim 1 , wherein

the at least one monomolecular photoinitiator is selected from 2,4,6-trimethylbenzoyl diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl) phenylphosphine oxide, dibenzoyldiethyl-germane, bis(4-methoxybenzoyl)diethylgermane (MBDEGe), tetrabenzoylgermane, tetrakis(o-methylbenzoyl)germane, tetrakis (mesitoyl) stannane or a mixture thereof, and

the at least one bimolecular photoinitiator is selected from camphorquinone (CQ), 2,2-dimethoxy-2-phenylacetophenone or a mixture thereof, in combination with 4-(dimethylamino)-benzoic acid ester (EDMAB).

17. The material according to claim 16 , wherein the one or more additives are selected from stabilizers, colorants, microbiocidal active ingredients, fluoride-ion-releasing additives, blowing agents, optical brighteners, plasticizers and UV absorbers.

18. The material according to claim 1 , wherein

the at least one monomolecular photoinitiator is bis(4-methoxybenzoyl)diethylgermane (MBDEGe), and

the at least one bimolecular photoinitiator is camphorquinone (CQ) in combination with 4-(dimethylamino)-benzoic acid ester (EDMAB).

19. The material according to claim 18 , wherein the one or more additives are selected from stabilizers, colorants, microbiocidal active ingredients, fluoride-ion-releasing additives, blowing agents, optical brighteners, plasticizers and UV absorbers.