Hydrosilylation cure inhibitors and use thereof

1 . A hydrosilylation curable silicone composition, consisting of:

(A) one or more polyorganosiloxanes, wherein the one or more polyorganosiloxanes contain at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and alkynyl groups, and having a viscosity in a range of 1,000 to 200,000 mPa·s at 25° C., and are free of fluoro-containing groups;

(B) a polyorganosiloxane containing at least two terminal silicon bonded hydrogen groups selected from the group consisting of branched and/or chain extended dimethylhydrogensiloxy-terminated polydimethylsiloxanes; dimethylhydrogensiloxy-terminated dimethylsiloxane-methylhydrogensiloxane copolymers; copolymers and/or silicon resins consisting of (CH 3 ) 2 HSiO 1/2 units, (CH 3 ) 3 SiO 1/2 units and SiO 4/2 units; copolymers and/or silicone resins consisting of (CH 3 ) 2 HSiO 1/2 units and SiO 4/2 units; copolymers and/or silicone resins consisting of (CH 3 ) 2 HSiO 1/2 units, SiO 4/2 units and (C 6 H 5 ) 3 SiO 1/2 units, and alternatives in which methyl is replaced by phenyl groups or other alkyl groups; tetrakis (dimethylsiloxy) silane; hydride-terminated polyphenylmethyl siloxane; hydride-terminated polyphenyl-(dimethylhydrosiloxy) siloxane; and phenyltris (dimethylsiloxy) silane;

(C) at least one hydrosilylation catalyst; and

(D) a hydrosilylation cure inhibitor consisting of,

a multiacrylate compound having at least three acrylate groups per molecule and selected from a triacrylate, a tetraacrylate, a pentaacrylate, a hexaacrylate, or a mixture thereof, and

optionally, hydrazines, triazoles, phosphines, mercaptans, organic nitrogen compounds, acetylenic alcohols, silylated acetylenic alcohols, maleates, fumarates, ethylenically or aromatically unsaturated amides, ethylenically unsaturated isocyanates, olefinic siloxanes, unsaturated hydrocarbon monoesters and diesters, conjugated ene-ynes, hydroperoxides, nitriles, diaziridines, or alkenyl-substituted siloxanes;

(E) optionally, one or more reinforcing fillers and/or non-reinforcing fillers;

(F) optionally, an adhesion promoter selected from monoacrylates, diacrylates, methacrylates, epoxy-containing alkoxysilanes, and methyltrimethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, 1,6-bis(trimethylsilyl)hexane, and 3-methacryloxypropyltrimethoxysilane;

(G) optionally, pigments selected from titanium dioxide, chromium oxide, bismuth vanadium oxide, iron oxides and mixtures thereof; carbon black; zinc oxide; lead oxide; zinc sulfide, lithophone; zirconium oxide; antimony oxide; iron oxide pigments; blue iron pigments; chromium oxide pigments; cadmium pigments; bismuth pigments; mixed metal oxide pigments; chromate and molybdate pigments; ultramarine pigments; cobalt oxide pigments; nickel antimony titanates; lead chrome; lampblack; aluminium; copper; copper oxide; bronze; stainless steel; nickel; zinc; brass; phthalocyanine pigments; monoarylide yellow; diarylide yellow; benzimidazolone yellow; heterocyclic yellow; DAN orange; quinacridone pigments; azo pigments; monoazo pigments; diazo pigments; azo pigment lakes; β-naphthol pigments; naphthol AS pigments; benzimidazolone pigments; diazo condensation pigment; isoindolinone; isoindoline pigments; polycyclic pigments; perylene and perinone pigments; thioindigo pigments; anthrapyrimidone pigments; flavanthrone pigments; anthanthrone pigments; dioxazine pigments, triarylcarbonium pigments; quinophthalone pigments; and diketopyrrolo pyrrole pigments; and

(H) optionally, silicone fluids selected from trimethylsilyl or OH terminated siloxanes polydimethylsiloxanes having a viscosity of less than (<) 150 mPa·s at 25° C.;

(I) optionally, one or more additives selected from adhesion catalysts, electrically conductive fillers, thermally conductive fillers, pot life extenders, flame retardants, UV light stabilizers, bactericides, wetting agents, heat stabilizers, and plasticizers, or a mixture thereof.

2 . The hydrosilylation curable silicone composition in accordance with claim 1 , wherein the multiacrylate compound has from three to five acrylate groups per molecule.

3 . The hydrosilylation curable silicone composition in accordance with claim 1 , wherein the multiacrylate compound is selected from pentaerythritol tetraacrylate, dipentaerythritol penta-/hexa-acrylate, pentaerythritol triacrylate, di (trimethylolpropane) tetraacrylate, trimethylolpropane triacrylate, or a mixture thereof.

4 . The hydrosilylation curable silicone composition in accordance with claim 1 , wherein the optional one or more acetylenic alcohols is/are present and is selected from 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol, 3-butyn-1-ol, 3-butyn-2-ol, propargyl alcohol, 1-phenyl-2-propyn-1-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynylcyclopentanol, 3-methyl-1-penten-4-yn-3-ol, and mixtures thereof.

5 . The hydrosilylation curable silicone composition in accordance with claim 1 , wherein the optional one or more reinforcing fillers and/or non-reinforcing fillers is/are present in the composition.

6 . The hydrosilylation curable silicone composition in accordance with claim 1 , which is stored before use in two parts, a part-A comprising components (C) and (A) and optionally filler, and a part-B comprising components (B) and (A) and optionally filler, such that components (C) and (B) are stored separately.

7 . The hydrosilylation curable silicone composition in accordance with claim 6 , wherein the optional one or more acetylenic alcohols is/are present in part-B and is selected from 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol, 3-butyn-1-ol, 3-butyn-2-ol, propargyl alcohol, 1-phenyl-2-propyn-1-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynylcyclopentanol, 3-methyl-1-penten-4-yn-3-ol, and mixtures thereof.

8 . A cured silicone material which is the cured product of the hydrosilylation curable silicone composition in accordance with claim 1 .

9 . A method of preparing a cured silicone material by mixing the components of the hydrosilylation curable silicone composition in accordance with claim 1 and curing the composition at a temperature between 80° C. and 250° C.

10 . The method in accordance with claim 9 , wherein the cured silicone material is a three-dimensional (3D) article, and wherein the method further comprises:

(i) printing an amount of the hydrosilylation curable silicone composition with a 3D printer to form a layer;

(ii) heating the layer to form an at least partially cured layer;

(iii) printing a second amount of the hydrosilylation curable silicone composition on the at least partially cured layer with the 3D printer to form a subsequent layer;

(iv) heating the subsequent layer to form an at least partially cured subsequent layer; and

(v) optionally, repeating steps (iii) and (iv) for any additional layer(s) to form the 3D article.

11 . A hydrosilylation curable silicone composition, consisting of:

(A) one or more polyorganosiloxanes, wherein the one or more polyorganosiloxanes contain at least two unsaturated groups per molecule, which unsaturated groups are selected from alkenyl and alkynyl groups, and having a viscosity in a range of 1,000 to 200,000 mPa·s at 25° C., and are free of fluoro-containing groups;

(B) a polyorganosiloxane containing at least two terminal silicon bonded hydrogen groups selected from the group consisting of branched and/or chain extended dimethylhydrogensiloxy-terminated polydimethylsiloxanes; dimethylhydrogensiloxy-terminated dimethylsiloxane-methylhydrogensiloxane copolymers; copolymers and/or silicon resins consisting of (CH 3 ) 2 HSiO 1/2 units, (CH 3 ) 3 SiO 1/2 units and SiO 4/2 units; copolymers and/or silicone resins consisting of (CH 3 ) 2 HSiO 1/2 units and SiO 4/2 units; copolymers and/or silicone resins consisting of (CH 3 ) 2 HSiO 1/2 units, SiO 4/2 units and (C 6 H 5 ) 3 SiO 1/2 units, and alternatives in which methyl is replaced by phenyl groups or other alkyl groups; tetrakis (dimethylsiloxy) silane; hydride-terminated polyphenylmethyl siloxane; hydride-terminated polyphenyl-(dimethylhydrosiloxy) siloxane; and phenyltris (dimethylsiloxy) silane;

(C) at least one hydrosilylation catalyst; and

(D) a hydrosilylation cure inhibitor consisting of,

a multiacrylate compound having at least three acrylate groups per molecule and selected from a triacrylate, a tetraacrylate, a pentaacrylate, a hexaacrylate, or a mixture thereof; and

optionally, hydrazines, triazoles, phosphines, mercaptans, organic nitrogen compounds, acetylenic alcohols, silylated acetylenic alcohols, maleates, fumarates, ethylenically or aromatically unsaturated amides, ethylenically unsaturated isocyanates, olefinic siloxanes, unsaturated hydrocarbon monoesters and diesters, conjugated ene-ynes, hydroperoxides, nitriles, diaziridines, or alkenyl-substituted siloxanes;

(E) optionally, one or more reinforcing fillers and/or non-reinforcing fillers;

(F) optionally, an adhesion promoter selected from monoacrylates, diacrylates, methacrylates, epoxy-containing alkoxysilanes, and methyltrimethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, 1,6-bis(trimethylsilyl)hexane, and 3-methacryloxypropyltrimethoxysilane;

(G) optionally, pigments selected from titanium dioxide, chromium oxide, bismuth vanadium oxide, iron oxides and mixtures thereof; carbon black; zinc oxide; lead oxide; zinc sulfide, lithophone; zirconium oxide; antimony oxide; iron oxide pigments; blue iron pigments; chromium oxide pigments; cadmium pigments; bismuth pigments; mixed metal oxide pigments; chromate and molybdate pigments; ultramarine pigments; cobalt oxide pigments; nickel antimony titanates; lead chrome; lampblack; aluminium; copper; copper oxide; bronze; stainless steel; nickel; zinc; brass; phthalocyanine pigments; monoarylide yellow; diarylide yellow; benzimidazolone yellow; heterocyclic yellow; DAN orange; quinacridone pigments; azo pigments; monoazo pigments; diazo pigments; azo pigment lakes; β-naphthol pigments; naphthol AS pigments; benzimidazolone pigments; diazo condensation pigment; isoindolinone; isoindoline pigments; polycyclic pigments; perylene and perinone pigments; thioindigo pigments; anthrapyrimidone pigments; flavanthrone pigments; anthanthrone pigments; dioxazine pigments, triarylcarbonium pigments; quinophthalone pigments; and diketopyrrolo pyrrole pigments;

(H) optionally, silicone fluids selected from trimethylsilyl or hydroxy dimethyl terminated polydimethylsiloxanes having a viscosity of less than (<) 150 mPa·s at 25° C.; and

(I) optionally, one or more additives selected from adhesion catalysts, electrically conductive fillers, thermally conductive fillers, pot life extenders, flame retardants, UV light stabilizers, bactericides, wetting agents, heat stabilizers, and plasticizers, or a mixture thereof.