Thermal and photocurable silicone composition and method for producing cured product thereof

Abstract

The present invention relates to a thermally and photocurable silicone composition in which the curing in the first stage and the curing in the second stage can be separately and easily managed. The present invention relates to an organopolysiloxane composition containing (A) an organopolysiloxane having at least three (meth) acryloyl groups in one molecule, (B) an organopolysiloxane having at least two alkenyl groups in one molecule and not having a (meth) acryloyl group, (C) an organohydrogenpolysiloxane having at least two hydrosilyl groups in one molecule, (D) a hydrosilylation reaction catalyst, and (E) a photopolymerization initiator, the ratio of the number of (meth) acryloyl groups contained in the component (A) to the number of alkenyl groups in the composition is 0.9-3.0, and the ratio of the number of hydrosilyl groups to the number of alkenyl groups is 0.8-1.2.

Description

Technical Field

[0001] The present invention relates to a heat- and light-curable silicone composition, and more particularly to a two-step curing liquid silicone composition which is semi-cured by a hydrosilylation reaction caused by heating in the presence of a hydrosilylation reaction catalyst and a photopolymerization initiator and then completely cured by free radical curing caused by ultraviolet rays, and a method for producing a cured product of the composition. Background Art

[0002] Two-step curing liquid silicone materials are attractive materials because they can manage the manufacturing process separately. For example, in the sealing material layer of an optical device, the light extraction efficiency changes depending on the dispersion of the phosphor, so the dispersion needs to be strictly managed. However, if a heat-curing material is used in the sealing material, the viscosity of the base material decreases during heat curing, and the phosphor becomes easy to precipitate, making it difficult to manage the dispersion and cure at the same time. Among them, if a two-step curing material is used in the sealing layer, first, by performing the first curing, the dispersion of the phosphor can be stably managed, and secondly, by performing the second curing, the hardness can be increased to the required hardness and installed on the semiconductor element at the same time.

[0003] Thus, in order to facilitate the manufacturing process that is accompanied by difficulties and develop a new manufacturing process that is different from the previous ones, two-stage curing silicone materials have been proposed for a wide range of uses such as adhesive films, optical device sealing materials, temporary fixing agents and adhesives for electronic device components, and research and development have been actively carried out.

[0004] Patent Document 1 reports that a liquid silicone composition comprising an alkenyl-containing organopolysiloxane, a platinum catalyst for a hydrosilylation reaction, and a high-energy ray-activated platinum catalyst is subjected to a primary curing by an addition reaction by subjecting the composition to a heated environment at room temperature, thereby obtaining a thermoplastic silicone having no fluidity at room temperature. Secondly, the thermoplastic silicone is irradiated with high-energy rays, and then subjected to a heated environment at room temperature to further subject the composition to a hydrosilylation reaction, thereby obtaining a silicone cured product having increased hardness.

[0005] Patent document 2 reports that a liquid silicone adhesive composition comprising an alkenyl-containing organopolysiloxane, a hydrosilylation reaction catalyst, and a thermal radical reaction initiator is subjected to a first-stage curing by an addition reaction in an environment of room temperature to 100°C, thereby obtaining a silicone cured product. Next, the obtained silicone cured product is subjected to a temperature environment of 150 to 190°C, which is higher than the curing temperature of the first stage, and a second-stage curing by a thermal radical reaction is performed, thereby obtaining a silicone cured product with high hardness.

[0006] Patent Document 3 reports that a liquid silicone adhesive composition containing an organopolysiloxane having a condensation-reactive group, an organopolysiloxane containing an alkenyl group, a condensation reaction catalyst, and a thermal radical reaction initiator is subjected to a condensation reaction in the presence of moisture to thereby carry out a first-stage curing to obtain a silicone cured product, and then the obtained silicone cured product is subjected to a heating environment to carry out a second-stage curing using a thermal radical reaction to obtain a silicone cured product having increased hardness.

[0007] However, the methods described in Patent Documents 1 and 2 use a curing mechanism in which both the first-stage curing and the second-stage curing start with heating. Generally, it is difficult to control the state during thermal curing, so in order to obtain the cured state of the organic silicon cured product obtained by the first curing with good reproducibility, it is necessary to strictly control the temperature distribution, and the methods of Patent Documents 1 and 2 are difficult to use in practice.

[0008] On the other hand, the method described in Patent Document 3 performs a first curing by a condensation reaction in which a large amount of exhaust components are generally generated, followed by a heat radical curing. Therefore, there is a possibility of a reverse reaction or decomposition due to volatilization of exhaust components.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: International Publication No. 2019 / 088066

[0012] Patent Document 2: Japanese Patent Application Publication No. 2007-191629

[0013] Patent Document 3: International Publication No. 2018 / 186165 Summary of the invention

[0014] Problems to be solved by the invention

[0015] The present invention has been made in view of the above-mentioned actual situation, and an object of the present invention is to provide a two-step curing silicone composition in which the first step curing and the second step curing can be separately and simply managed.

[0016] Means for solving problems

[0017] The present inventors have conducted intensive studies to solve the above-mentioned problems and have found that a composition containing an organopolysiloxane containing a (meth)acryloyl group, an organopolysiloxane containing an alkenyl group, and an organohydrogenpolysiloxane in a predetermined ratio can be cured by first-stage heat and second-stage light separately and simply in the presence of a hydrosilylation reaction catalyst and a photopolymerization initiator, thereby completing the present invention.

[0018] That is, the present invention provides:

[0019] 1. A heat- and light-curable silicone composition comprising:

[0020] (A) an organopolysiloxane having at least three (meth)acryloyl groups in one molecule,

[0021] (B) an organopolysiloxane having at least two alkenyl groups in one molecule and having no (meth)acryloyl group,

[0022] (C) an organohydrogenpolysiloxane having at least two hydrosilyl groups in one molecule,

[0023] (D) a hydrosilylation reaction catalyst, and

[0024] (E) a photopolymerization initiator,

[0025] The ratio of the number of (meth)acryloyl groups contained in the component (A) to the number of alkenyl groups in the composition is 0.9 to 3.0,

[0026] The ratio of the number of hydrosilyl groups to the number of alkenyl groups is 0.8 to 1.2.

[0027] 2. The heat- and light-curable silicone composition according to 1, wherein the component (A) is (Ai), (A-ii), or both of the following:

[0028] (Ai) an organopolysiloxane represented by the following formula (1)

[0029] [Chemistry 1]

[0030]

[0031] (Where R 1 are independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, R 2 independently represent an oxygen atom or an alkylene group having 1 to 20 carbon atoms, R 3 Each of the siloxane units in parentheses with k and m is an arbitrary order.)

[0032] (A-ii) an organopolysiloxane represented by the following formula (2) and having a number average molecular weight (Mn) of 3,000 to 100,000

[0033] A p (R 1 3SiO 1 / 2 ) q (SiO 4 / 2 ) r (2)

[0034] (Where R 1 represents the same meaning as above, A is a siloxane unit represented by the following formula (3), and p, q, and r are numbers satisfying p>0, q>0, r>0, and p+q+r=1.

[0035] [Chemistry 2]

[0036]

[0037] (Where R 1 , R 2 and R 3 represents the same meaning as above, n represents an integer of 0 to 10, and c represents an integer of 1 to 3. )

[0038] 3. The heat- and light-curable silicone composition according to 1, wherein the component (B) is (B-iii), (B-iv), or both of the following:

[0039] (B-iii) a linear organopolysiloxane having a viscosity of 50 to 10,000,000 mPa·s at 23° C. represented by the following formula (4)

[0040] R 4 R 1 2Si(OSiR 1 2) S i 1 2R 4 (4)

[0041] (Where R 1 Means the same as above, R 4 represents an alkenyl group having 2 to 20 carbon atoms, and s represents an integer of 1 to 10000. )

[0042] (B-iv) an organopolysiloxane represented by the following formula (5)

[0043] (R 1 3SiO 1 / 2 ) t (R 4 R 1 2SiO 1 / 2 ) u (SiO 4 / 2 ) v (5)

[0044] (Where R 1 and R 4 It has the same meaning as above, and t, u and v are numbers satisfying t>0, u>0, v>0, and (t+u+v)=1.

[0045] 4. The heat- and light-curable silicone composition according to 1, wherein the component (C) is a linear organohydrogenpolysiloxane represented by the following formula (7):

[0046] (R 1 3SiO 1 / 2 ) w (H (3-f) R 1 f SiO 1 / 2 ) 2-w (HR 1 1SiO 2 / 2 ) x (R 1 2SiO 2 / 2 ) y (7)(where R 1 represents the same meaning as above, f represents 1 or 2, w represents an integer satisfying 0≤w≤2, and x and y represent positive integers satisfying 2≤x+y≤800 and 0.6≤x / (x+y+2)≤1.0. )

[0047] 5. The heat- and light-curable silicone composition according to 1, wherein the component (E) is a photoradical polymerization initiator that does not contain nitrogen atoms, sulfur atoms, and phosphorus atoms.

[0048] 6. A method for producing a cured product, comprising: (α) heating the heat- and light-curable silicone composition according to any one of 1 to 5 to partially cure the composition to obtain a semi-cured composition; and (β) irradiating the semi-cured composition with ultraviolet rays to completely cure it.

[0049] Effects of the Invention

[0050] The heat- and light-curable silicone composition of the present invention has different curing initiation methods in the two-stage curing process, so the curing control and handling are easy. That is, the first stage curing by light can be carried out at room temperature and in a short time because the polymerization reaction proceeds instantaneously during ultraviolet irradiation, and the semi-cured composition after the first curing is easy to handle and does not change in hardness for a long time in a low-temperature environment such as refrigeration, so a time margin can be ensured until the second stage curing by heat is carried out.

[0051] The heat- and light-curable silicone composition of the present invention having such properties can be used, in particular, for adhesive films, optical device sealing materials, adhesives for electronic device members, and the like. DETAILED DESCRIPTION

[0052] The present invention will be described in detail below.

[0053] The heat- and light-curable silicone composition according to the present invention comprises the following components (A) to (E).

[0054] [1](A)Component

[0055] The component (A) in the heat- and light-curable silicone composition of the present invention is an organopolysiloxane having at least three (meth)acryloyl groups in one molecule, preferably the following (Ai), (A-ii), or both. In the present invention, the so-called (meth)acryloyl group means an acryloyl group or a methacryloyl group.

[0056] (Ai) an organopolysiloxane represented by the following formula (1)

[0057] [Chemistry 3]

[0058]

[0059] (Where R 1 are independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, R 2 independently represent an oxygen atom or an alkylene group having 1 to 20 carbon atoms, R 3 Each of the siloxane units in parentheses with k and m is an arbitrary order.)

[0060] (A-ii) an organopolysiloxane represented by the following formula (2) and having a number average molecular weight (Mn) of 3,000 to 100,000

[0061] A p (R 1 3SiO 1 / 2 ) q (SiO 4 / 2 ) r (2)

[0062] (Where R 1represents the same meaning as above, A is a siloxane unit represented by the following formula (3), and p, q, and r are numbers satisfying p>0, q>0, r>0, and p+q+r=1.

[0063] [Chemistry 4]

[0064]

[0065] (Where R 1 , R 2 and R 3 represents the same meaning as above, n represents an integer of 0 to 10, and c represents an integer of 1 to 3. )

[0066] As R 1 The alkyl group may be a linear, branched or cyclic group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, cyclohexyl, n-octyl, 2-ethylhexyl and n-decyl groups.

[0067] In addition, as R 1 Specific examples of the aryl group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms include phenyl, tolyl, xylyl, naphthyl and the like.

[0068] In addition, part or all of the hydrogen atoms bonded to the carbon atoms may be substituted with other substituents. Specific examples thereof include halogen-substituted hydrocarbon groups such as chloromethyl, bromoethyl, trifluoropropyl, and cyanoethyl, and cyano-substituted hydrocarbon groups.

[0069] Among these, R 1 , preferably an alkyl group having 1 to 5 carbon atoms or a phenyl group, and more preferably a methyl group, an ethyl group or a phenyl group.

[0070] R 2 The alkylene group having 1 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include methylene, ethylene, propylene, trimethylene, tetramethylene, isobutylene, pentamethylene, hexamethylene, heptamethylene, octamethylene and nonamethylene.

[0071] Among these, R 2 , preferably an oxygen atom, a methylene group, an ethylene group, or a trimethylene group, and more preferably an oxygen atom or an ethylene group.

[0072] As R 3 Specific examples of include groups represented by the following formulae, but are not limited to these.

[0073] [Chemistry 5]

[0074]

[0075] (In the formula, g represents an integer of 1 to 4.)

[0076] In the above formula (1), a and b are integers of 0 to 3, and the sum of a and b and m (a+b+m) is 3 or more. If a+b+m is less than 3, it is difficult for the photocuring reaction to occur, and the hardness of the obtained silicone cured product may become insufficient. In particular, a and b are 2, and m is preferably 4.

[0077] k is an integer of 0 to 1000, and the polymerizability may be poor when k exceeds 1000. From the viewpoint of low volatility and polymerizability of the component (Ai), k is preferably an integer of 30 to 500, and more preferably an integer of 50 to 400.

[0078] m is an integer of 0 to 20, preferably an integer of 0 to 10, and more preferably 0. When m exceeds 20, white turbidity may occur during curing of the composition.

[0079] In the above formula (2), p, q, and r are numbers that satisfy p>0, q>0, r>0, and p+q+r=1. From the perspective of the handleability of the composition and the hardness of the resulting silicone cured product, p is preferably 0.05 to 0.07, q is preferably 0.33 to 0.35, and r is preferably 0.58 to 0.62.

[0080] The number average molecular weight of component (A-ii) is in the range of 3,000 to 100,000, preferably in the range of 5,000 to 10,000. If the number average molecular weight is less than 3,000, the number of (meth)acryloyl groups contained in one molecule may be less than 3, and the hardness of the silicone cured product obtained after two-stage curing may become insufficient. If the number average molecular weight exceeds 100,000, the compatibility of component (A-ii) may be reduced.

[0081] In addition, the number average molecular weight in the present invention is a standard polystyrene conversion value measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as an elution solvent.

[0082] (A) The component may be used alone or in combination of two or more.

[0083] In addition, since the component (A-ii) is sometimes in a solid state in the use environment, it can be used by dissolving it in the component (Ai) or a liquid organic compound containing a (meth)acryloyl group in advance.

[0084] From the viewpoint of handling properties, the viscosity of the component (A) as a whole at 23°C is preferably 100,000 mPa·s or less (usually 1 to 100,000 mPa·s), and more preferably 10,000 mPa·s or less (eg 5 to 10,000 mPa·s).

[0085] It should be noted that the viscosity in the present invention is a value measured using a B-type rotational viscometer.

[0086] [2] (B) Component

[0087] The component (B) in the heat- and light-curable silicone composition of the present invention is an organopolysiloxane having at least two alkenyl groups in one molecule and no (meth)acryloyl group, and is preferably (B-iii), (B-iv), or both of the following.

[0088] (B-iii) a linear organopolysiloxane having a viscosity of 50 to 10,000,000 mPa·s at 23° C. represented by the following formula (4)

[0089] R 4 R 1 2Si(OSiR 1 2) S i 1 2R 4 (4)

[0090] (Where R 1 Means the same as above, R 4 represents an alkenyl group having 2 to 20 carbon atoms, and s represents an integer of 1 to 10000. )

[0091] (B-iv) an organopolysiloxane represented by the following formula (5)

[0092] (R 1 3SiO 1 / 2 ) t (R 4 R 1 2SiO 1 / 2 ) u (SiO 4 / 2 ) v (5)

[0093] (Where R 1 and R 4 It has the same meaning as above, and t, u and v are numbers satisfying t>0, u>0, v>0, and (t+u+v)=1.

[0094] In the above formula (4), R 1 , examples include the same groups as those for the above formula (1), preferably methyl and phenyl.

[0095] R 4 The alkenyl group having 2 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include vinyl, allyl, butenyl, pentenyl, hexenyl and octenyl. Among these, vinyl is preferred.

[0096] s is an integer of 1 to 10,000, preferably an integer of 100 to 1,000.

[0097] The viscosity of the component (B-iii) at 25°C is 50 to 10,000,000 mPa·s, preferably 100 to 100,000 mPa·s.

[0098] In the above formula (5), R 1 , examples include the same groups as those for the above formula (1), preferably methyl and phenyl.

[0099] R 4 The alkenyl group having 2 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include vinyl, allyl, butenyl, pentenyl, hexenyl and octenyl. Among these, vinyl is preferred.

[0100] Each of t, u and v is a number satisfying t>0, u>0, v>0 and (t+u+v)=1. From the viewpoint of curability and hardness of the cured product, (t+u) / v is preferably 0.3 to 2.0, more preferably 0.5 to 1.0.

[0101] The number average molecular weight of component (B-iv) is preferably 500 to 500,000, more preferably 1,000 to 100,000. If the number average molecular weight is less than 500, the number of alkenyl groups contained in one molecule may be less than 2, and the hardness of the silicone cured product obtained after two-stage curing may become insufficient. If the number average molecular weight exceeds 500,000, the compatibility of component (B-iv) may be reduced.

[0102] The component (B) may be used alone or in combination of two or more.

[0103] In addition, since the component (B-iv) is sometimes in a solid state in the environment of use, it can be dissolved in the component (B-iii) before use.

[0104] From the viewpoint of handling properties, the viscosity of the component (B) as a whole at 23°C is preferably 100,000 mPa·s or less (usually 1 to 100,000 mPa·s), and more preferably 10,000 mPa·s or less (eg 5 to 10,000 mPa·s).

[0105] The amount of component (B) is such that the ratio of the number of (meth)acryloyl groups in component (A) to the number of alkenyl groups in the composition is 0.9 to 3.0. If the ratio is less than 0.9, the second stage curing may be insufficient, and if it exceeds 3.0, the amount of alkenyl groups is too small, and the first stage curing may be insufficient.

[0106] [3] (C) Component

[0107] The component (C) is an organohydrogenpolysiloxane having at least two hydrosilyl groups in one molecule, and specifically includes an organohydrogenpolysiloxane represented by the following average composition formula (6).

[0108] R 1 d H e SiO (4-d-e) / 2 (6)

[0109] (Where R 1 It has the same meaning as above, d represents a number satisfying 0.7 to 2.1, e represents a number satisfying 0.001 to 1.0, and 0.8≤d+e≤3.0.)

[0110] In the above formula (6), d is preferably 1.0 to 1.8, e is preferably 0.1 to 1, and d+e is preferably 1≤d+e≤2.4, and more preferably 1.6≤d+e≤2.2. Within such a range, foaming during curing can be suppressed, the hardness of the obtained cured product is further improved, and changes in hardness over time are less likely to occur.

[0111] In particular, as the component (C), a linear organohydrogenpolysiloxane represented by the following formula (7) is preferred.

[0112] (R 1 3SiO 1 / 2 ) w (H (3-f) R 1 f SiO 1 / 2 ) 2-w (HR 1 1SiO 2 / 2 ) x (R 1 2SiO 2 / 2 ) y (7)

[0113] In formula (7), as R 1 , examples include the same groups as those in the above formula (1), and a methyl group is preferred.

[0114] f is 1 or 2, preferably 2.

[0115] w is an integer satisfying 0≤w≤2, preferably 0 or 2, more preferably 2.

[0116] x and y are positive integers satisfying 2≤x+y≤800 and 0.6≤x / (x+y+2)≤1.0, and preferably positive integers satisfying 7≤x+y≤700 and 0.7≤x / (x+y+2)≤0.9.

[0117] The kinematic viscosity of the component (C) at 23°C is preferably 0.5 to 200 mm 2 / s, more preferably 1 to 50 mm 2 / s. The kinematic viscosity is a value measured using a Canon-Fenske viscometer.

[0118] The component (C) may be used alone or in combination of two or more.

[0119] The amount of component (C) is such that the ratio of the number of hydrosilyl groups to the number of alkenyl groups in the composition is in the range of 0.8 to 1.2, preferably in the range of 0.9 to 1.1. If it is less than 0.8, the curability of the first-stage curing and the hardness of the obtained cured product may be insufficient, and if it exceeds 1.2, the hardness becomes too high due to the first-stage curing, and the advantage of performing the second-stage curing may disappear.

[0120] [4] (D) Component

[0121] The component (D) is a hydrosilylation reaction catalyst for accelerating the addition reaction between the alkenyl groups in the components (A) and (B) and the Si—H groups in the component (C).

[0122] Specific examples thereof include carbon powder loaded with platinum metal, platinum black, platinum chloride, chloroplatinic acid, reaction products of chloroplatinic acid and monohydric alcohols, complexes of platinum and vinylsiloxanes such as divinyltetramethyldisiloxane, complexes of chloroplatinic acid and olefins, platinum-based catalysts such as platinum diacetoacetate, palladium-based catalysts, platinum group metal-based catalysts such as rhodium-based catalysts, and the like. Among these, catalysts containing platinum are preferred from the viewpoint of reactivity, and complexes of platinum and vinylsiloxane are more preferred.

[0123] The amount of component (D) to be blended is not limited as long as it is an amount that promotes the hydrosilylation reaction. It is preferably an amount in the range of 0.01 to 500 ppm, more preferably 0.05 to 100 ppm, and even more preferably 0.01 to 50 ppm, calculated as the mass of the metal in component (D), relative to the total of components (A), (B) and (C).

[0124] [5] (E) Component

[0125] The component (E) is a photopolymerization initiator that generates organic radical species by absorbing ultraviolet rays, which serves as the starting point for the (meth)acryloyl polymerization reaction. The photopolymerization initiator of the component (E) preferably does not contain nitrogen atoms, sulfur atoms, or phosphorus atoms so as not to inhibit the first-stage curing mechanism, i.e., the addition reaction.

[0126] Specific examples of such photopolymerization initiators include 2,2-diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one (Omnirad 651 manufactured by IGM Resins BV (Co., Ltd.), 1-hydroxy-cyclohexyl-phenyl-ketone (Omnirad 184 manufactured by IGM Resins BV (Co., Ltd.), 2-hydroxy-2-methyl-1-phenyl-propane-1-one (Omnirad 1173 manufactured by IGM Resins BV (Co., Ltd.), 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propane-1-one (Omnirad 127 manufactured by IGM Resins BV (Co., Ltd.), and methyl phenylglyoxylate (Omnirad MBF manufactured by IGM Resins BV (Co., Ltd.).

[0127] Among these, 2,2-diethoxyacetophenone and 2-hydroxy-2-methyl-1-phenyl-propane-1-one (Omnirad 1173 manufactured by IGM Resins BV) are preferred from the viewpoint of compatibility with the components (A) and (B).

[0128] The component (E) may be used alone or in combination of two or more.

[0129] The amount of component (E) added is preferably in the range of 0.01 to 20% by mass based on the total mass of components (A), (B) and (C). Within this range, the curing property is good and the deep curing property is excellent.

[0130] [6] Other ingredients

[0131] In addition to the above-mentioned components (A) to (E), the heat- and light-curable silicone composition of the present invention may further contain other components as long as the purpose of the present invention is not impaired.

[0132] As other components, for example, there can be listed reaction control agents such as 3-methyl-1-butyn-3-ol and ethynylmethyldecylmethanol for controlling the reactivity of the platinum catalyst; adhesion aids having adhesion-imparting groups such as carbonyl, epoxy, and alkoxysilyl groups; thixotropy control agents such as fumed silica; reinforcing agents such as crystalline silica; antioxidants; light stabilizers; heat resistance improvers such as metal oxides and metal hydroxides; pigments such as titanium oxide; dyes; thermal conductivity-imparting fillers such as aluminum oxide; viscosity modifiers such as non-reactive silicone oils having no reactive functional groups; conductivity-imparting agents such as metal powders such as silver and gold, etc.

[0133] The heat- and light-curable silicone composition of the present invention can be prepared by mixing the above-mentioned components (A) to (E) and other components used as necessary by a known method.

[0134] In this case, the composition of the present invention may be prepared as a one-component type (one-liquid type), a two-component type (two-liquid type), or three or more parts, and mixed at any ratio when used.

[0135] The method for producing a cured product of a heat- and photo-curable silicone composition of the present invention comprises: (α) heating the heat- and photo-curable silicone composition to partially cure the composition to obtain a semi-cured composition; and (β) irradiating the obtained semi-cured composition with ultraviolet rays to completely cure it.

[0136] The heating conditions in the step (α) are preferably 50 to 150° C., more preferably 80 to 120° C., for 10 minutes to 1 day, more preferably 30 minutes to 1 hour.

[0137] The ultraviolet rays irradiated in step (β) are preferably light with a wavelength of 200 to 500 nm, more preferably 200 to 350 nm. From the viewpoint of preventing discoloration, the irradiation temperature is preferably 20 to 40° C., and the irradiation intensity is more preferably 30 to 2000 mW / cm 2 The irradiation dose is preferably 150 to 100,000 mJ / cm 2 .

[0138] As the light source of ultraviolet light, a 365nm UV-LED lamp, a metal halide lamp, a high-pressure mercury lamp, etc. can be used. As the ultraviolet irradiation method, a method of irradiating the composition with an appropriate amount of ultraviolet light can be listed. When it is carried out on a transparent substrate such as glass or a resin film, ultraviolet light can also be irradiated through glass or a film. When irradiating ultraviolet light, in order to suppress the influence of oxygen that hinders curing, it is preferably set under a nitrogen or argon atmosphere.

[0139] Example

[0140] The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[0141] In the following, the viscosity at 23° C. is measured using a B-type rotational viscometer, and the kinematic viscosity at 23° C. is measured using a Canon-Fenske viscometer. In addition, Vi represents a vinyl group, and Me represents a methyl group.

[0142] [1] Preparation of heat- and light-curable silicone compositions

[0143] [Examples 1-1 to 1-6, Comparative Examples 1-1 to 1-5]

[0144] The components (A) to (E) shown below and other components were mixed in the amounts (parts by mass) shown in Tables 1 and 2 to prepare heat- and photo-curable silicone compositions.

[0145] (A)Ingredients

[0146] (Ai-1): an organopolysiloxane represented by the following formula (8) (viscosity at 23° C.: 3000 mPa·s, acryloyl group content: 0.02 mol / 100 g)

[0147] [Chemistry 6]

[0148]

[0149] (In the formula, the arrangement of each siloxane unit in parentheses is random or blocky.)

[0150] (A-ii-1): Siloxane unit represented by the following formula (9): (ViMe2SiO 1 / 2 unit) / (Me3SiO 1 / 2 Organopolysiloxane (number average molecular weight 5700, average number of methacryloyl groups in one molecule 3.7, methacryloyl amount 0.0656 mol / 100 g, vinyl amount 0.0164 mol / 100 g) with a molar ratio of (SiO2 unit) / (SiO2 unit) of 0.056 / 0.014 / 0.390 / 0.540

[0151] [Chemistry 7]

[0152]

[0153] (A-ii-2): Siloxane unit represented by the above formula (9) / (ViMe2SiO 1 / 2 unit) / (Me3SiO 1 / 2Organopolysiloxane (number average molecular weight 5400, average number of methacryloyl groups in one molecule 4.3, methacryloyl amount 0.0794 mol / 100 g, vinyl amount 0.0596 mol / 100 g) with a molar ratio of (SiO2 unit) / (SiO2 unit) of 0.072 / 0.054 / 0.334 / 0.540

[0154] (B) Ingredients

[0155] (B-iii-1): an organopolysiloxane represented by the following formula (10) (viscosity at 23°C: 3000 mPa·s, vinyl group content: 0.01 mol / 100 g)

[0156] [Chemistry 8]

[0157]

[0158] (In the formula, the arrangement of each siloxane unit in parentheses is random or block.)

[0159] (B-iv-1): an organopolysiloxane represented by the following average formula (11) (number average molecular weight 4500, average number of vinyl groups per molecule 3.7, vinyl amount 0.082 mol / 100 g)

[0160] (ViMe2SiO 1 / 2 ) 0.058 (Me3SiO 1 / 2 ) 0.402 (SiO 4 / 2 ) 0.540 (11)

[0161] (C) Ingredients

[0162] (C-1): an organohydrogenpolysiloxane represented by the following formula (12) (kinematic viscosity at 23°C: 44.7 mm 2 / s, content of hydrogen atoms bonded to silicon atoms = 0.0113 mol / g)

[0163] [Chemistry 9]

[0164]

[0165] (In the formula, the arrangement of each siloxane unit in parentheses is random or block.)

[0166] (D) Ingredients

[0167] (D-1) Toluene solution of platinum 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum content 0.5 mass%)

[0168] (E) Ingredients

[0169] (E-1): 2-Hydroxy-2-methyl-1-phenyl-propane-1-one (Omnirad 1173 manufactured by IGM Resins BV)

[0170] (Other ingredients)

[0171] Reaction control agent: ethynyl methyl decyl methanol

[0172] Diluent: a disiloxane compound represented by the following structural formula (13):

[0173] [Chemistry 10]

[0174]

[0175] [Table 1]

[0176]

[0177] [Table 2]

[0178]

[0179] [2] Production of cured products of heat- and light-curing silicone compositions

[0180] [Examples 2-1 to 2-6, Comparative Examples 2-1 to 2-6]

[0181] The heat and light curing silicone compositions obtained in Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-5 were left to stand at 120°C for 1 hour to perform the first stage of curing. After the obtained cured product was cooled to 25°C, the needle penetration or Durometer A hardness of the cured product was measured using a penetrometer (1 / 4 cone) or Durometer A hardness meter manufactured by Rigo Co., Ltd. in accordance with JIS K 6249. In the case where the needle penetration was less than 1 and could not be measured, the Durometer A hardness was used.

[0182] Next, the cured product obtained by the first stage of curing was irradiated with a UV-LED lamp having a wavelength of 365 nm at an intensity of 100 mW / cm at 25°C in a nitrogen atmosphere. 2 and a dose of 3000mJ / cm 2 The second stage of curing was performed by irradiating ultraviolet rays in the manner of , and the hardness of the cured product was measured in the same manner as in the first stage. The results are shown in Tables 3 and 4.

[0183] [Table 3]

[0184]

[0185] [Table 4]

[0186]

[0187] As shown in Tables 3 and 4, it can be seen that the heat- and light-curable silicone compositions prepared in Examples 1-1 to 1-6 have a large difference in hardness between the first-stage curing by heat and the second-stage curing by light.

[0188] On the other hand, in the case of using the compositions of Comparative Examples 1-1 and 1-3 in which the ratio of the number of (meth)acryloyl groups in the component (A) to the number of alkenyl groups in the composition exceeded 3.0, the first-stage curing by heat did not occur. In the case of using the compositions of Comparative Examples 1-2, 1-4, and 1-5 in which the ratio of the number of (meth)acryloyl groups in the component (A) to the number of alkenyl groups in the composition was, it was found that the first-stage curing by heat excessively proceeded, and there was almost no difference in hardness after the second-stage curing, and the material did not become a two-stage curing type.

Claims

1. A heat- and light-curable silicone composition comprising: (A) an organopolysiloxane having at least three (meth)acryloyl groups in one molecule, (B) an organopolysiloxane having at least two alkenyl groups in one molecule and having no (meth)acryloyl group, (C) an organohydrogenpolysiloxane having at least two hydrosilyl groups in one molecule, (D) a hydrosilylation reaction catalyst, and (E) a photopolymerization initiator, The ratio of the number of (meth)acryloyl groups contained in the component (A) to the number of alkenyl groups in the composition is 0.9 to 3.0, The ratio of the number of hydrosilyl groups to the number of alkenyl groups is 0.8 to 1.

2.

2. The heat- and light-curable silicone composition according to claim 1, wherein The component (A) is the following (Ai), (A-ii), or both. (Ai) an organopolysiloxane represented by the following formula (1) [Chemistry 1] In the formula, R 1 are independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, R 2 independently represent an oxygen atom or an alkylene group having 1 to 20 carbon atoms, R 3 independently represent an acryloyloxyalkyl group, a methacryloyloxyalkyl group, an acryloyloxyalkoxy group, or a methacryloyloxyalkoxy group, k represents an integer of 0 to 1000, m represents an integer of 0 to 20, a and b independently represent an integer of 0 to 3, and a+b+m is an integer greater than 3; the order of arrangement of the siloxane units in parentheses with k and m is arbitrary; (A-ii) an organopolysiloxane represented by the following formula (2) and having a number average molecular weight Mn of 3,000 to 100,000 A p (R 1 3SiO 1 / 2 ) q (SiO 4 / 2 ) r (2) In the formula, R 1 represents the same meaning as above, A is a siloxane unit represented by the following formula (3), p, q, r are numbers satisfying p>0, q>0, r>0 and p+q+r=1; [Chemistry 2] In the formula, R 1 , R 2 and R 3 represents the same meanings as above, n represents an integer of 0-10, and c represents an integer of 1-3.

3. The heat- and light-curable silicone composition according to claim 1, wherein The component (B) is the following (B-iii), (B-iv), or both. (B-iii) a linear organopolysiloxane having a viscosity of 50 to 10,000,000 mPa·s at 23° C. represented by the following formula (4), R 4 R 1 2Si(OSiR 1 2) S Sports and Recreation Center 1 2R 4 (4) In the formula, R 1 Means the same as above, R 4 represents an alkenyl group having 2 to 20 carbon atoms, and s represents an integer of 1 to 10000; (B-iv) an organopolysiloxane represented by the following formula (5) (R 1 3SiO 1 / 2 ) t (R 4 R 1 2SiO 1 / 2 ) u (SiO 4 / 2 ) v (5) In the formula, R 1 and R 4 It represents the same meaning as above, and t, u and v are numbers that satisfy t>0, u>0, v>0, and (t+u+v)=1 respectively.

4. The heat- and light-curable silicone composition according to claim 1, wherein The component (C) is a linear organohydrogenpolysiloxane represented by the following formula (7): (R 1 3SiO 1 / 2 ) w (H (3-f) R 1 f SiO 1 / 2 ) 2-w (HR 1 1SiO 2 / 2 ) x (R 1 2SiO 2 / 2 ) y (7) In the formula, R 1 represents the same meaning as above, f represents 1 or 2, w represents an integer satisfying 0≤w≤2, and x and y represent positive integers satisfying 2≤x+y≤800 and 0.6≤x / (x+y+2)≤1.

0.

5. The heat- and light-curable silicone composition according to claim 1, wherein The component (E) is a photoradical polymerization initiator containing no nitrogen atom, sulfur atom or phosphorus atom.

6. A method for producing a solidified product, comprising: (α) a step of heating the heat- and light-curable silicone composition according to any one of claims 1 to 5 to partially cure the composition to obtain a semi-cured composition; and (β) A step of irradiating the obtained semi-cured composition with ultraviolet rays to completely cure it.

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