KR20030001465A - Curable Silicone Compositions Having Enhanced Cure-Through-Volume - Google Patents

Abstract

The present invention relates to a photocurable silicone composition comprising an additive that provides cure-through-volume (CTV) throughout the composition. The additive is preferably a curable amino silyl-terminated polyorganosiloxane.

Description

Curable Silicone Compositions Having Enhanced Cure-Through-Volume

Curing over the entire volume (CTV) is an important property of the photocurable silicone composition. Conventional curable silicone compositions have limited curing capabilities in potting applications where the bond-gap must be large or deep. For example, CTVs of about 2 cm to about 5 cm are typical of conventional curable silicones. In addition, the use of filler materials and pigments further hinders effective transmission to the silicone composition of the photocuring source.

To improve CTV, conventional methods have focused on the reduction or removal of fillers and pigment additives, or the use of polymers that can be cured through more than one curing mechanism. For example, one approach has been to use silicone polymers that are capable of both light curing and wet curing. Compositions containing such polymers have their advantages, but it is desirable to have the ability to improve the CTV without depending on the secondary curing mechanism and the particular polymer typically used for it. Reduction or removal of filler material has not been a viable alternative since the overall physical properties of the cured polymer often reach a level that is not commercially available. Therefore, there is a need for a photocurable silicone composition that overcomes the CTV limitations of conventional techniques, does not damage the structural integrity of the cured silicone, and is able to cure deeper without the need for polymers that rely on secondary curing mechanisms for CTV increase. . It is also advantageous to use photocurable silicone compositions that are less sensitive to the amount of filler or the opacity of the composition as a whole.

Summary of the Invention

The present invention relates to photocurable silicone compositions having improved physical properties due to the incorporation of curable silicone-based additives, in particular increased CTV. Curable silicone-based additives may be incorporated in amounts sufficient to provide improved CTV, elongation or other desirable properties. For example, when the additive is incorporated in an amount of about 25% by weight or less, preferably about 0.1% to about 15%, more preferably about 1% to about 2% of the total silicone composition, the silicone-based additive The depth to cure is deeper and the bond spacing to cure is wider compared to similar compositions such as two-component cured silicone compositions and the like that do not incorporate a.

One aspect of the invention

a) at least one photocurable silicone polymer,

b) photoinitiators and

c) at least one curable amino functionalized silicone or silane additive

It includes a photocurable silicone composition containing.

Preferably the curable amino functionalized silicone additive is composed of at least one end-capping silane component, preferably at least two end-capping silane components, having end-capping groups different from the silanol-terminated polyorganosiloxanes. Curable alkoxy / amino silyl-terminated polymers or polymer blends formed through the reaction.

Another aspect of the invention

(i) providing a photocurable silicone polymer and photoinitiator, and

(ii) at least one silanol-terminated polyorganosiloxane and (i) at least one end-capping silane component having a different reactive end-capping group, preferably at least two end-capping silane components Incorporating the curable alkoxy / amino silyl-terminated polymer additive comprising the reaction product

It includes a method of producing a photocurable composition, wherein the curing over the entire volume is improved.

Another aspect of the present invention includes a method of improving the curing (CTV) over the entire volume of a curable composition by applying the above-mentioned silicone composition to a substrate and exposing it to light irradiation sufficient to cause curing.

The present invention relates to curable silicone compositions with improved cure-through-volume (CTV). More particularly, the present invention relates to curable silicone compositions incorporating curable amino functionalized silanes or curable amino silyl-terminated silicones as additives to improve properties. The additive is preferably an alkoxy / amino silyl-terminated polymer composition which is a reaction product of silanol-terminated polyorganosiloxane and two or more end-capping silane components having different end-capping groups. .

Photocurable Silicone Ingredients

The photocurable silicone component can be any photocurable silicone polymer. Examples of useful photocurable silicone polymers are described in US Pat. Nos. 4,675,346, 4,528,081, 5,300,608 and 4,699,802, all of which are incorporated herein by reference.

More particularly, reactive silicone polymers include compounds corresponding to the following structures:

Where

R ¹ is H or alkyl C _1-10 , preferably methyl,

R ² is a divalent hydrocarbon or hydrocarbonoxy group, for example alkylene, alkyleneoxy, alkenylene or arylene,

R ³ and R ⁴ may be the same or different and are C _1-10 monovalent hydrocarbon radicals, preferably alkyl, substituted alkyl, aryl, substituted aryl, alkoxy, aryloxy, (meth) acrylic acid, oxime, acetoxy , N, N-dialkylamino, N, N-dialkylamineoxy, N-alkylamido or Wherein R is H or hydrocarbyl, , ego,

R ⁵ is a C _1-10 monovalent hydrocarbon radical,

n is an integer from about 1 to 1200. R ² is preferably alkylene or alkenylene C _1-3 , for example propylene and propenylene. Examples of useful R ³ and R ⁴ groups include alkyl, such as methyl and ethyl; Halo alkyls such as trifluoropropyl; Phenyl and benzyl. If wet curing is desired, R ³ and R ⁴ are preferably hydrolyzable groups, most preferably methoxy groups.

These reactive silicone polymers are preferably prepared from materials having at least one terminal terminated in the silanol group. The process for preparing the photocurable silicone polymer comprises reacting the above-mentioned material having at least one end terminating in the silanol group with a silane containing at least one photocurable group, preferably more than one photocurable group. Include.

Silanes useful for preparing photocurable silicone polymers may have a structure of Formula II:

Where

R ⁶ and R ⁷ may be the same or different monovalent hydrocarbon radicals having C _1-10 , and R ⁶ is 1 to 10 carbon atoms selected from the group consisting of 0, N and S, wherein the hetero atom is a halo atom Monovalent heterohydrocarbon radicals.

R ⁶ and R ⁷ are preferably selected from the group consisting of methyl, ethyl, isopropyl, vinyl, phenyl, methacryloxypropyl and norbornenyltrimethoxy, R ⁷ is methyl, ethyl, isopropyl and CH ₂ It is preferably selected from the group consisting of CH ₂ 0CH ₃ .

For example, preferred silanes are represented by the formula:

Wherein R ¹ , R ² , R ³ and R ⁴ are as defined above.

Other polyalkoxysilanes useful in the present invention include the following compounds:

Also contemplated are primary, secondary and tertiary amino silanes. For example, n-methylaminopropyltrimethoxysilane, n-ethylaminopropyltrimethoxysilane, n-butylaminopropyltrimethoxysilane, n, n-diethylaminopropyl-trimethoxysilane, n, Both n-dimethylaminopropyltrimethoxysilane has been found to be useful.

The above-mentioned silane component is reacted with at least one silanol-terminated polymer component, which may actually be any useful silanol-terminated material. Useful polymer components include silanol-terminated polydimethylsiloxanes and combinations thereof from about 50 cps to about 150,000 cps. Silanol-terminated polyorganosiloxanes have the structure of Formula III:

Where

A is a polymer or copolymer backbone that may be any number of combinations of polyurethane, silicone, polyamide, polyether, and the like.

One example of such silanol-terminated polymer backbone is polydimethylsiloxane having the structure of Formula IV:

Since the number of repeat units will determine the molecular weight, it will determine the viscosity of this starting material. Therefore, n can be an integer, for example from about 1 to about 1,200, preferably from about 10 to about 1,000. The viscosity of these materials is not critical and can be easily selected to suit the particular use of the product, especially since the viscosity of the terminated end product of the reaction will be substantially the same as the viscosity of the silanol-terminated reactant. The viscosity of these silanol-terminated polymer backbones may range from about 1 cps to about 150,000 cps (using a Brookfield viscometer, 25 ° C.). Preferably, the silanol-terminated polymer backbone used in the present invention is about 50 to about 150,000 cps.

As described in the above-mentioned US Pat. No. 5,300,508, the reaction for preparing the photocurable silicone polymer is efficiently carried out using a catalytically effective amount of catalyst, preferably an organolithium reagent. The organolithium reagent is represented by the formula LiR ¹⁴ , wherein the organic R ¹⁴ group can be C _1-18 alkyl, aryl, alkaryl, arylalkyl, alkenyl, alkynyl, amine-containing compound or organosilicon-containing compound Can be represented

More particularly, when the organolithium reagent is alkyl-lithium, this is, among other things, methyl-lithium, n-butyl lithium, sec-butyl lithium, t-butyl lithium, n-hexyl lithium, 2-ethylhexyl lithium and n-octyl lithium Can be selected from.

Phenyl lithium, vinyl lithium, lithium phenylacetylide, lithium (trimethylsilyl) acetylide, lithium dimethylamide, lithium diethylamide, lithium diisopropylamide and lithium dicyclohexylamide are also useful catalyst reagents for forming photocurable silicone polymers. .

In addition, the organic R ¹⁴ group is O (SiR ¹¹ R ¹² O) _t SiR ¹¹ R ¹² R ¹³ where R ¹¹ and R ¹² are monovalent hydrocarbon radicals C _1-10 and R ¹³ is C _1-18 alkyl or aryl And t is an integer).

The catalyst used to prepare the photocurable silicone polymer is used in an amount of about 1 to about 1000 ppm based on the effective amount of the catalyst, preferably the atomic weight of lithium.

The reaction process for preparing the photocurable silicone polymer includes adding silanol-terminated organosiloxane, terminal-terminated silane and organolithium solution to the reaction vessel. The mixture is then stirred for about 0.5 to about 5 hours at room temperature to about 110 ° C., preferably 25 ° C. to about 60 ° C., with no moisture, for example under nitrogen conditions, until the end-capping is complete. Heat. The mixture is then further cooled after bubbling or quenching with liquid carbon dioxide or dry ice. If desired, the formed lithium carbonate can be easily removed through filtration. If desired, the catalyst is neutralized, preferably in carbon dioxide in dry ice form. It may also be neutralized with compounds such as acid and silyl phosphate, silyl acetate and the like. Water condenses during the neutralization process. If volatiles are present, they are vacuum stripped. Equal molar amounts of silanol-terminated organopolysiloxanes and end-capping silanes can be used in the reaction (based on the moles of SiOH functional groups in the case of silanol-terminated organopolysiloxanes), but excess of end-capping silanes desirable. When preparing one component of a two-component curing composition, it is desirable to add only a small excess of end-capping silane to control the possible viscosity increase. Therefore, for example, in such a case, it is preferable to add 1.0 to 1.5 moles of alkoxysilane for each mole of silanol.

In addition, the reactive silicone composition of the present invention may be cured using a curing mechanism or using conditions other than photocuring conditions. For example, wet curing, irradiation with actinic rays such as ultraviolet rays or visible light, heat, anaerobic curing, or a combination of these mechanisms can be used.

The resulting liquid can then be mixed with other conventional additives such as fillers, initiators, accelerators, pigments, dehumidifiers and the like to form a one-component curable composition. Fillers such as hydrophobic fumed silica or quartz function to impart desirable physical properties to the cured material. Dehumidifying agents such as methyltrimethoxysilane and vinyltrimethyloxysilane are useful.

Photoinitiator components

The amount of photoinitiator used in the composition will typically range from about 0.1% to 5% of the composition. However, if it performs the function of initiating the polymerization of photocurable groups quickly and efficiently, an amount outside this range may be used without departing from the present invention, depending on the nature of the particular photoinitiator. In particular, higher percentages may be required when silicon-bonded photoinitiators are used at equally high weights per photoinitiator.

Although photoinitiators are used as separate components, it is to be understood that the composition used in the methods of the present invention is intended to include compositions wherein the photoinitiator groups are included on the same organopolysiloxane polymer backbone that includes the photocurable groups discussed above. Preferred photocuring groups that can be attached to the organopolysiloxanes include acrylate, methacrylate and glycidoxy groups.

Additive Components to Improve Curing Properties

The additive for improving the curing properties may be an amino functionalized reactive silane, or more preferably a curable amino silyl-terminated polymer or a blend of such polymers. Most preferably the additive for improving the curing properties is formed by reacting at least one silanol-terminated polymer with at least one end-capping silane component having a different end-capping component and preferably at least two silanes. At least one alkoxy / amino silyl-terminated polymer. This reaction preferably takes place in the presence of a catalyst. The most preferred catalyst reagent may be any of the organolithium reagents mentioned above used to make the photocurable silicone polymer component described herein.

The curable alkoxy / amino silyl-terminated polymer additive may be a combination of reactive silicone polymers, but preferably comprises a predominant amount of alkoxy / amino silyl-terminated end-capped reactive polymers corresponding to the structure of Formula (V) :

Where

A is a backbone portion selected from silanes, polyurethanes, polyesters and combinations thereof,

n is an integer, for example, the integer of 1-1,200.

A is preferably a polyorganosiloxane represented by the following repeating structure:

Where

R ¹ and R ² may be the same or different monovalent hydrocarbon radicals C _1-10 , preferably a methyl group,

R ³ and R ⁵ are different functional groups of up to 10 carbon atoms, including (meth) acryl, amino (primary, secondary and tertiary amines), vinyl, alkoxy, aryloxy, acetoxy, oxime and combinations thereof Or R ³ or R ⁵ may be a monovalent heterohydrocarbon radical having up to 10 carbon atoms (C _1-10 ), wherein the hetero atom is selected from 0, N and S,

R ⁴ is alkyl (C _1-10 ), preferably methyl, ethyl or isopropyl, or may be —CH ₂ CH ₂ 0CH ₃ .

Curable amino / silyl-terminated polymer additives of the present invention are provided for various hybrid end-capping combinations. The curable silyl-terminated polymer additive components are referred to as "hybrids" because of their reactive termination ends. For example, one terminating silicon atom on the reaction product may have alkoxy and amino functionalities, directly or indirectly, while other terminating silicon atoms may have alkoxy and vinyl functionalities, directly or indirectly. Particularly preferred reactive polymers formed by the process of the present invention are reactive silicone polymers comprising a combination of amino, vinyl and alkoxy terminating functional groups and having different end-capping groups.

Curable amino or alkoxy / amino silyl-terminated polymer additives can include a reaction product mixture that is a combination of a hybrid end-capped reactive silicone combination and a non-hybrid end-capped reactive silicone. Preferably, the hybrid end-capped silicone is present in an amount prevailing relative to the non-hybrid silicone reaction product, and more preferably, the hybrid is present in an amount relative to the total reaction product combination.

Formation of the curable alkoxy / amino silyl-terminated polymer additive selects an amount of each silane to yield an amino silyl-terminated polymer, preferably an alkoxy / amino silyl-terminated polymer having different reactive end-capping groups Is achieved. The silane (s) with slower reaction rates are preferably provided in excess of silane with higher reaction rates. Each relative amount will depend on the silane chosen. Preferably, the ratio of other silanes to one silane is about 10: 1 to about 1:10. In an embodiment in which three different silanes are added, the preferred ratio is about 1: 2: 1. The use of more than three silanes is also contemplated.

As mentioned above, the curable alkoxy / amino silyl- or alkoxy / amino silyl-terminated polymer additives comprise two or more end-capping silane components that have different reactive end-capping groups than the one or more silanol-terminated polymers. It may be a blend of polymers formed by reacting. Blends formed as reaction products preferably retain a predominant amount of the hybrid polymer as discussed above. The amount of each silane required to obtain a predominant amount of hybrid reaction product can be determined in advance. For example, prior to the reaction, the hydroxy content of the silanol-terminated polymer component, for example silanol-terminated polyorganosiloxane, is determined by a suitable method. Based on the hydroxy content of the silanol-terminated components, the total amount of silane and the relative amount of each silane is obtained in a predominant amount of the desired hybrid reaction product or in which the desired ratio of different end-capping groups to the final reaction product is achieved. Can be calculated The reaction product of the present invention preferably comprises at least about 35%, more preferably at least about 60%, of silyl-terminated polymers having different reactive end-capping groups. There may also be other non-hybrid polymers bearing reactive end groups. It is desirable to carefully determine the relative amounts of the silane components in order to calculate the reaction rate difference and to ensure that there are no silanes that cannot provide substantially the desired end-capping. The total amount of silane components is preferably an amount sufficient to substantially complete the end-capping reaction of the silanol-terminated polymer (s). Preferably, from about 0.5 mole to about 4.5 mole of silane component is added per mole of silanol-terminated polymer backbone component.

Aminopropyldimethoxy / vinyldimethoxy terminated polydimethylsiloxane polymers (hybrid DAM / VDM polymers) are examples of particularly preferred curable alkoxy / amino silyl-terminated polymer additives of the present invention. These polymer additives react aminoaminoalkoxysilane (DAM) and vinyl alkoxysilane (VDM) with silanol-terminated polydimethylsiloxane at a composition ratio of DAM: VDM of 17.67% by weight: 82.33% by weight of amino: vinyl in the reaction product. It is formed by causing the molar ratio of the functional group to be produced as 1: 1. In the resulting reaction product, there is a predominant amount of reactive polymer having the structure of formula VI:

Examples of primary, secondary and tertiary amino silanes that can be used as additives to improve properties include n-methylaminopropyltrimethoxysilane, n-ethylaminopropyltrimethoxysilane, n-butylaminopropyltrimeth Methoxysilane, n, n-diethylaminopropyltrimethoxysilane, n, n-dimethylaminopropyl-trimethoxysilane, and the like.

The invention can be further understood with reference to the following non-limiting examples. Unless stated otherwise, weight percent means corresponding values per total composition. Unless stated otherwise, the viscosity was measured at 10 rpm, 25 ° C. using a Brookfield viscometer using a No. 6 or No. 4 spindle.

Example I

Reactive silicones of the following composition were prepared according to the above-mentioned method.

Composition A

ingredient weight%

Methacryloxylpropyldimethoxy polydimethylsiloxane 77%

Silicone oil poly (dimethylsiloxane) 3.3%

Acrylic polymer 5.5%

Silicon Dioxide3.3%

Photoinitiator 3.3%

Modified acrylamide2.2%

^* Silane adhesion promoter 3.3%

^* Substituted silane dehumidifier 1.1%

^* Amino free silane

Curable alkoxy silyl-terminated polymer additive was added to Composition A in an amount of about 10% by weight of the total composition. The additive was a blend of alkoxy silyl-terminated reactive silicones, at least the predominant amount of which was vinyldimethoxy / aminopropyldimethoxy terminated polydimethylsiloxane.

The entire reactive silicone composition was placed in an aluminum weighing dish and UV cured at 70 mW / cm ² (365 nm) for 1 minute. The cured sample was removed from the dish and any uncured material was removed from the cured sample. CTV was measured to be 6.1 mm. This is for comparison with the initial composition (composition A without curable polymer additive) with a CTV of 3.3 mm under the same curing conditions.

Example II

Composition B was prepared having the following components and representative of conventional reactive silicone compositions.

Composition B

ingredient weight%

Methacrylate-terminated poly (dimethylsiloxane) 49.5%

Vinyl-terminated poly (dimethylsiloxane) 31%

Silicone oil poly (dimethylsiloxane) 3%

5% acrylate

Modified Silicon Dioxide4.5%

Photoinitiator 1%

Modified acrylamide 2%

Silane Adhesion Promoter 3%

1% of substituted silane dehumidifier

Composition B was considered a control. Four more samples were prepared by adding the hybrid additive vinyldimethoxy / aminopropyl-dimethoxy terminated poly (dimethyl-siloxane) to Composition B in different amounts. Each sample was placed in a separate aluminum weighing dish and UV cured at 70 mW / cm ² (365 nm) for 1 minute. Each sample was removed from the dish and any uncured material was removed from the cured sample. The cured samples were then compared to the cured samples of Composition B without hybrid vinyldimethoxy / aminopropyl-dimethoxy terminated poly (dimethyl-siloxane) additives for CTV thickness. The results obtained from the five samples are shown in Table I below.

sample % Of curable amino silyl-terminated hybrid polymer additive CTV 1 (control) none 5.5 mm 2 1.15% 7.5 mm 3 0.56% 6.1 mm 4 1.96% 8.5 mm 5 3.05% 8.6 mm

As can be seen in Table I, CTV was significantly increased relative to the control by incorporating curable silyl-terminated polymer additives.

Example III

Composition C was prepared having the following composition and representative of conventional reactive silicone compositions.

Composition C

ingredient weight%

Methacrylate-terminated poly (dimethylsiloxane) 66.5%

Vinyl-terminated poly (dimethylsiloxane) 15%

Silicone oil poly (dimethylsiloxane) 3%

5% acrylate

Modified Silicon Dioxide3.5%

Photoinitiator 1%

Modified acrylamide 2%

Silane derivative adhesion promoter 3%

1% of substituted silane dehumidifier

Aminopropyltrimethoxy silane was added to Composition C in an amount of 0.2% in place of the curable hybrid vinyldimethoxy / aminopropyldimethoxy terminated poly (dimethyl) siloxane to determine the effect on cure over the entire volume. This mixture was placed in an aluminum weighing dish and UV cured at 180 mW / cm ² (365 nm) for 30 seconds. The cured sample was removed from the dish and any uncured material was removed from the cured sample. The curing over the entire volume of the sample was then determined to be 8.3 mm thick.

Example IV

Composition D was prepared having the following components and representative of conventional reactive silicone compositions.

Composition D

ingredient weight%

Methacrylate-terminated poly (dimethylsiloxane) 70%

Vinyl-terminated poly (dimethylsiloxane) 15%

5% acrylate

Modified Silicon Dioxide 3%

Photoinitiator 1%

Modified acrylamide 2%

Silane derivative adhesion promoter 3%

1% of substituted silane dehumidifier

1% hybrid vinyldimethoxy / aminopropyldimethoxy terminated poly (dimethyl) siloxane additive was incorporated into Composition D. This mixture was placed in an aluminum weighing dish and UV cured at 180 mW / cm ² (365 nm) for 30 seconds. The cured sample was removed from the dish and any uncured material was removed from the cured sample. The cure over the entire volume of the sample was then determined to be 10.3 mm thick.

Example V

Composition E

The CTV of the ultraviolet curable adhesive composition with acryloxymethyl-terminated poly (dimethyl-siloxane) as reactive silicone in the composition was tested with or without the additive of the present invention to determine the effect on the CTV. 3.17% curable hybrid vinyldimethoxy / aminopropyldimethoxy terminated poly (dimethyl) siloxane additive was added to Composition F. Composition F without additives was used as a control. Both samples were placed in separate aluminum weighing dishes and UV cured at 70 mW / cm ² (365 nm) for 30 seconds. The cured sample was removed from the dish and any uncured material was removed from the cured sample. The CTV of each sample was measured. The composition F without the additive had a CTV of 4.70 mm, whereas the composition F with the hybrid curable polymer additive 3.17% had a CTV of 4.95 mm.

Claims (12)

a. Photocurable silicone polymer, b. Photoinitiators and c. Curable amino silyl-terminated polymer additive comprising a reaction product of at least one silanol-terminated polyorganosiloxane and at least one end-capping silane component Photocurable silicone composition comprising a. The composition of claim 1, wherein the polymer additive is present in an amount sufficient to increase cure-through-volume (CTV) over the entire volume as compared to the same composition without the additive. The composition of claim 1, wherein the polymer additive comprises a predominant amount of a polymer corresponding to the structure of formula V: <Formula V> Where A is a polymer or copolymer backbone selected from the group consisting of polyurethanes, silicones, polyamides, polyethers, polyesters and combinations thereof, n is an integer from 1 to 1,200, R ³ and R ⁵ are different functional groups having up to 10 carbon atoms and are selected from (meth) acrylic, amino, vinyl, alkoxy, aryloxy, acetoxy, oxime and combinations thereof, or R ³ or R ⁵ is May be a monovalent heterohydrocarbon radical having up to 10 carbon atoms (C _1-10 ) wherein the hetero atom is selected from 0, N and S R ⁴ is alkyl (C _1-10 ) or —CH ₂ CH ₂ 0CH ₃ . The composition of claim 1, wherein the curable amino silyl-terminated polymer additive comprises vinyldimethoxy / aminopropyldimethoxy terminated polydimethylsiloxane. The composition of claim 1, wherein the polymer additive is present in an amount of about 0.2-15% by weight of the total silicone composition. The composition of claim 1 wherein the photocurable silicone polymer corresponds to the structure of formula (I) <Formula I> Where R ¹ is H or alkyl C _1-10 , R ² is a divalent hydrocarbon or hydrocarbonoxy group, R ³ and R ⁴ may be the same or different and are C _1-10 monovalent hydrocarbon radicals, R ⁵ is a C _1-10 monovalent hydrocarbon radical, n is an integer from 1 to 1200. The compound of claim 6, wherein R ³ and R ⁴ are alkyl, substituted alkyl, aryl, substituted aryl, alkoxy, aryloxy, (meth) acrylic, oxime, acetoxy, N, N-dialkylamino, N, N -Dialkylamineoxy, N-alkylamido, Wherein R is H or hydrocarbyl, , And combinations thereof. The composition of claim 1, wherein the photocurable silicone composition is also wet curable. The composition of claim 1 wherein the photoinitiator is selected from the group consisting of benzoin, benzophenone, acetophenone and combinations thereof. The composition of claim 8 further comprising a wet curable catalyst. (i) providing a photocurable silicone polymer and photoinitiator, and (ii) incorporating in (i) the curable amino silyl-terminated polymer additive comprising the reaction product of at least one silanol-terminated polyorganosiloxane and at least one silane component A method of producing a photocurable silicone composition, wherein the cured through-volume (cure-through-volume, CTV) is improved. (i) a. Photocurable silicone polymer, b. Photoinitiators and c. Curable amino silyl-terminated polymer additive comprising a reaction product of at least one silanol-terminated polyorganosiloxane and at least one end-capping silane component Providing a photocurable silicone composition comprising a (ii) applying the photocurable silicone composition to a substrate and exposing the silicone composition to radiation sufficient for photocuring; A method of improving curing over the entire volume of a photocurable silicone composition comprising a.