Photocurable and heat-curable silicone composition and method for producing cured product thereof

Abstract

According to the silicone composition, the first-stage curing and the second-stage curing can be managed simply and separately. 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 photopolymerization initiator, and (E) a hydrosilylation reaction catalyst, in 100 g of the composition, the content of (meth) acryloyl groups contained in the component (A) is 1-15 mmol, the ratio of the number of alkenyl groups in the composition to the number of (meth) acryloyl groups contained in the component (A) is 0.5 or more, and the ratio of the number of hydrosilyl groups to the number of alkenyl groups and (meth) acryloyl groups contained in the component (A) and the component (B) is 0.8-3.0.

Description

Technical Field

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

[0002] Two-stage 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 settle, making it difficult to manage the dispersion and cure at the same time. Among them, if a two-stage 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 it can be mounted on the semiconductor element.

[0003] Thus, in order to help make difficult manufacturing processes easier and develop new manufacturing processes different from the past, two-stage curing silicone materials have been proposed and actively researched and developed for a wide range of uses such as adhesive films, optical device sealing materials, temporary fixing agents for components of electronic equipment, and adhesives.

[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 first-stage curing temperature, and a second-stage curing by a thermal radical reaction is performed, thereby obtaining a silicone cured product having increased 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. Subsequently, the obtained silicone cured product is subjected to a heating environment to carry out a second-stage curing using a thermal radical reaction to thereby obtain a silicone cured product having an 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 are started by 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 that generally generates a large amount of exhaust components and then performs a heat radical curing. Therefore, there is a possibility of a reverse reaction or decomposition of exhaust components due to volatilization.

[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 managed separately and simply.

[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 separately and simply managed in the presence of a photopolymerization initiator and a hydrosilylation reaction catalyst to perform first-stage curing using light and second-stage curing using heat, thereby completing the present invention.

[0018] That is, the present invention provides:

[0019] 1. A light- and heat-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 photopolymerization initiator, and

[0024] (E) a hydrosilylation reaction catalyst,

[0025] The (meth)acryloyl group contained in the component (A) in 100 g of the composition is 1 to 15 mmol,

[0026] The ratio of the number of alkenyl groups in the composition to the number of (meth)acryloyl groups contained in the component (A) is 0.5 or more,

[0027] The ratio of the number of hydrosilyl groups to the number of alkenyl groups and (meth)acryloyl groups contained in the components (A) and (B) is 0.8 to 3.0.

[0028] 2. The light- and heat-curable silicone composition according to 1, wherein the component (A) is (Ai), (A-ii), or both of the following:

[0029] (Ai) an organopolysiloxane represented by the following formula (1),

[0030] [Chemistry 1]

[0031]

[0032] (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.)

[0033] (A-ii) an organopolysiloxane represented by the following formula (2) and having a number average molecular weight (Mn) of 3,000 to 100,000,

[0034] A p (R 1 3SiO 1 / 2 ) q (SiO 4 / 2 ) r (2)

[0035] (Where R 1 represents the same meaning as above, A is a siloxane unit represented by the following formula (3), p, q, and r are numbers satisfying p>0, q>0, r>0, and p+q+r=1.

[0036] [Chemistry 2]

[0037]

[0038] (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. )

[0039] 3. The light- and heat-curable silicone composition according to 1, wherein the component (B) is (B-iii), (B-iv), or both of the following:

[0040] (B-iii) a linear organopolysiloxane represented by the following formula (4) and having a viscosity at 23°C of 50 to 10,000,000 mPa·s,

[0041] R 4 R 1 2Si(OSiR 1 2) S OSR 1 2R 4 (4)

[0042] (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. )

[0043] (B-iv) an organopolysiloxane represented by the following formula (5),

[0044] (R 1 3SiO 1 / 2 ) t (R 4 R 1 2SiO1 / 2 ) u (SiO 4 / 2 ) v (5)

[0045] (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.

[0046] 4. The light- and heat-curable silicone composition according to 1, wherein the component (C) is a linear organohydrogenpolysiloxane represented by the following formula (7):

[0047] (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. )

[0048] 5. The light- and heat-curable silicone composition according to 1, wherein the component (D) is a photoradical polymerization initiator containing no nitrogen atom, sulfur atom, or phosphorus atom.

[0049] 6. A method for producing a solidified product, comprising:

[0050] (α) irradiating the light and heat curable silicone composition according to any one of 1 to 5 with ultraviolet rays to partially cure the composition to obtain a semi-cured composition; and

[0051] (β) A step of heating the obtained semi-cured composition to completely cure it.

[0052] Effects of the Invention

[0053] The light- and heat-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 state of the 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 margin of time can be ensured until the second stage curing by heat is carried out.

[0054] The light- and heat-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

[0055] The present invention will be described in detail below.

[0056] The light and heat curable silicone composition according to the present invention contains the following components (A) to (E).

[0057] [1](A)Ingredients

[0058] The component (A) in the light- and heat-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.

[0059] (Ai) an organopolysiloxane represented by the following formula (1)

[0060] [Chemistry 3]

[0061]

[0062] (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.)

[0063] (A-ii) an organopolysiloxane represented by the following formula (2) and having a number average molecular weight (Mn) of 3,000 to 100,000

[0064] A p (R 1 3SiO 1 / 2 ) q (SiO 4 / 2 ) r (2)

[0065] (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.

[0066] [Chemistry 4]

[0067]

[0068] (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. )

[0069] 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.

[0070] 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.

[0071] Furthermore, 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] As R 3 Specific examples of include groups represented by the following formulae, but are not limited to these.

[0076] [Chemistry 5]

[0077]

[0078] (In the formula, g represents an integer of 1 to 4.)

[0079] 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.

[0080] 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.

[0081] m is an integer of 0 to 20, preferably an integer of 0 to 10, and more preferably 0. When m exceeds 20, the composition may become cloudy during curing.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] (A) The component may be used alone or in combination of two or more.

[0086] 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.

[0087] 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).

[0088] It should be noted that the viscosity in the present invention is a value measured using a B-type rotational viscometer.

[0089] The amount of (meth)acryloyl groups contained in the component (A) is in the range of 1 to 15 mmol, preferably 1.5 to 14 mmol, relative to 100 g of the composition. If it is less than 1 mmol / 100 g, the first-stage curing may be insufficient, and if it exceeds 15 mmol / 100 g, the hardness becomes too high by the first-stage curing, and the advantage of performing two-stage curing may disappear.

[0090] [2] (B) Component

[0091] The component (B) in the light and heat 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.

[0092] (B-iii) a linear organopolysiloxane represented by the following formula (4) having a viscosity at 23°C of 50 to 10,000,000 mPa·s

[0093] R 4 R 1 2Si(OSiR 1 2) S OSR 1 2R 4 (4)

[0094] (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. )

[0095] (B-iv) an organopolysiloxane represented by the following formula (5)

[0096] (R 1 3SiO 1 / 2 ) t (R 4 R 1 2SiO1 / 2 ) u (SiO 4 / 2 ) v (5)

[0097] (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.

[0098] In the above formula (4), 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] s is an integer of 1 to 10,000, preferably an integer of 100 to 1,000.

[0101] 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.

[0102] In the above formula (5), R 1 , examples include the same groups as those for the above formula (1), preferably methyl and phenyl.

[0103] 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.

[0104] 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.

[0105] 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 organosilicon 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.

[0106] The component (B) may be used alone or in combination of two or more.

[0107] In addition, since the component (B-iv) is sometimes in a solid state in the use environment, it can be used by dissolving it in the component (B-iii) in advance.

[0108] 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).

[0109] The amount of component (B) is such that the ratio of the number of alkenyl groups in the composition to the number of (meth)acryloyl groups in component (A) is 0.5 or more, preferably 0.5 to 30. If it is less than 0.5, the hardness change due to the second step curing becomes small, and the advantage of two-step curing may disappear.

[0110] [3] (C) Component

[0111] The component (C) is an organohydrogenpolysiloxane having at least two hydrosilyl groups in one molecule, and specifically, an organohydrogenpolysiloxane represented by the following average composition formula (6) is exemplified.

[0112] R 1 d H e SiO (4-d-e) / 2 (6)

[0113] (Where R 1 represents the same meaning as above, d represents a number satisfying 0.7 to 2.1, and e represents a number satisfying 0.001 to 1.0 and 0.8≤d+e≤3.0. )

[0114] 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 the hardness is less likely to change over time.

[0115] In particular, a linear organohydrogenpolysiloxane represented by the following formula (7) is preferred as the component (C).

[0116] (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)

[0117] In formula (7), as R 1 , examples include the same groups as those in the above formula (1), and a methyl group is preferred.

[0118] f is 1 or 2, preferably 2.

[0119] w is an integer satisfying 0≤w≤2, preferably 0 or 2, and more preferably 2.

[0120] 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.

[0121] The kinematic viscosity of the component (C) at 23°C is preferably 0.5 to 1000 mm 2 / s, more preferably 1 to 100 mm 2 / s. The kinematic viscosity is a value measured using a Canon-Fenske viscometer.

[0122] The component (C) may be used alone or in combination of two or more.

[0123] The amount of component (C) is such that the ratio of the number of hydrosilyl groups / the number of alkenyl groups and (meth)acryloyl groups contained in components (A) and (B) is in the range of 0.8 to 3.0, preferably in the range of 0.9 to 2.0. If it is less than 0.8, the curability in the second stage curing and the hardness of the obtained cured product may be insufficient, and if it exceeds 3.0, the hardness of the obtained cured product changes greatly over time.

[0124] [4] (D) Component

[0125] The component (E) is a photopolymerization initiator that generates organic free radical species by absorbing ultraviolet rays, which serves as the starting point for the polymerization reaction of the (meth)acryloyl group. The photopolymerization initiator of the component (D) preferably does not contain nitrogen atoms, sulfur atoms, or phosphorus atoms so as not to hinder 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 (D) may be used alone or in combination of two or more.

[0129] The amount of component (D) 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] [5] (E) Component

[0131] The component (E) 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).

[0132] 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.

[0133] The amount of the component (E) to be blended is not limited as long as it is an amount that promotes the hydrosilylation reaction, but is preferably in the range of 0.01 to 500 ppm, more preferably in the range of 0.05 to 100 ppm, and even more preferably in the range of 0.01 to 50 ppm, calculated as the mass of the metal in the component (E) relative to the total of the components (A), (B) and (C).

[0134] [6] Other ingredients

[0135] The light and heat curable silicone composition of the present invention may contain other components in addition to the above-mentioned components (A) to (E) unless the purpose of the present invention is impaired.

[0136] 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.

[0137] The light and heat 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.

[0138] 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.

[0139] The method for producing a cured product of a light- and heat-curable silicone composition of the present invention comprises: (a) irradiating the light- and heat-curable silicone composition with ultraviolet rays to partially cure the composition to obtain a semi-cured composition; and (b) heating the semi-cured composition to completely cure it.

[0140] The ultraviolet rays irradiated in step (α) 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 .

[0141] 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 with ultraviolet light, in order to suppress the influence of oxygen that hinders curing, it is preferably set under a nitrogen or argon atmosphere.

[0142] The heating conditions in the step (β) 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.

[0143] Example

[0144] 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.

[0145] 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.

[0146] [1] Preparation of light- and heat-curable silicone compositions

[0147] [Examples 1-1 to 1-7, Comparative Examples 1-1 to 1-6]

[0148] 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 light- and heat-curable silicone compositions.

[0149] (A)Ingredients

[0150] (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)

[0151] [Chemistry 6]

[0152]

[0153] (In the formula, the arrangement of each siloxane unit in parentheses is random or blocky.)

[0154] (Ai-2): an organopolysiloxane represented by the following formula (9) (viscosity at 23° C.: 1000 mPa·s, acryloyl group content: 0.026 mol / 100 g)

[0155] [Chemistry 7]

[0156]

[0157] (A-ii-1): Siloxane unit represented by the following formula (10): (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

[0158] [Chemistry 8]

[0159]

[0160] (B) Ingredients

[0161] (B-iii-1): an organopolysiloxane represented by the following formula (11) (viscosity at 23°C: 3000 mPa·s, vinyl group content: 0.01 mol / 100 g)

[0162] [Chemistry 9]

[0163]

[0164] (In the formula, the arrangement of each siloxane unit in parentheses is random or block.)

[0165] (B-iii-2): an organopolysiloxane represented by the following formula (12) (viscosity at 23°C: 1600 mPa·s, vinyl group content: 0.013 mol / 100 g)

[0166] [Chemistry 10]

[0167]

[0168] (B-iii-3): an organopolysiloxane represented by the following formula (13) (viscosity at 23°C: 5000 mPa·s, vinyl group content: 0.006 mol / 100 g)

[0169] [Chemistry 11]

[0170]

[0171] (B-iv-1): an organopolysiloxane represented by the following average formula (14) (number average molecular weight 4500, average number of vinyl groups in one molecule 3.7, vinyl amount 0.082 mol / 100 g)

[0172] (ViMe2SiO 1 / 2 ) 0.058 (Me3SiO 1 / 2) 0.402 (SiO 4 / 2 ) 0.540 (14)

[0173] (C) Ingredients

[0174] (C-1): an organohydrogenpolysiloxane represented by the following formula (15) (kinematic viscosity at 23°C: 4.5 mm 2 / s, content of hydrogen atoms bonded to silicon atoms = 0.0145 mol / g)

[0175] [Chemistry 12]

[0176]

[0177] (In the formula, the arrangement of each siloxane unit in parentheses is random or block.)

[0178] (D) Ingredients

[0179] (D-1): 2-Hydroxy-2-methyl-1-phenyl-propane-1-one (Omnirad 1173 manufactured by IGM Resins BV)

[0180] (E) Ingredients

[0181] (E-1)

[0182] Toluene solution of platinum 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum content 0.5 mass%)

[0183] (Other ingredients)

[0184] Reaction control agent: ethynylmethyldecylmethanol Diluent: disiloxane compound represented by the following structural formula (16)

[0185] [Chemistry 13]

[0186] [Table 1]

[0187] Example 1-1 1-2 1-3 1-4 1-5 1-6 1-7 (Ai-1) 10 50 10 70 (Ai-2) 10 10 (A-ii-1) 16 (B-iii-1) 90 50 45 15 80 (B-iii-2) 90 (B-iii-3) 45 (B-iv-1) 45 15 45 (C-1) 0.9 1.2 3.6 2.4 1.2 3.6 3.5 (D-1) 0.6 0.6 0.6 0.6 0.6 0.6 0.6 (E-1) 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Reaction control agent 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Thinner 4 (A) (meth)acryloyl group amount of component [mmol / 100g] 2.0 9.7 1.9 13.5 2.5 2.5 10.2 Ratio of alkenyl groups to (meth)acryloyl groups 4.5 0.5 20.7 1.0 4.5 15.2 1.0 Ratio of Si-H groups / [(meth)acryloyl groups + alkenyl groups] 1.2 1.2 1.2 1.3 1.2 1.2 1.2

[0188] [Table 2]

[0189] Comparative Example 1-1 1-2 1-3 1-4 1-5 1-6 (Ai-1) 5 80 90 90 (Ai-2) 3 (A-ii-1) 1 (B-iii-1) 95 10 5 10 98.75 (B-iii-2) 97 (B-iv-1) 10 5 (C-1) 0.9 2.2 2 1.7 1 1.1 (D-1) 0.6 0.6 0.6 0.6 0.6 0.6 (E-1) 0.5 0.5 0.5 0.5 0.5 0.5 Reaction control agent 0.4 0.4 0.4 0.4 0.4 0.4 Thinner 0.25 (A) (meth)acryloyl group amount of component [mmol / 100g] 1.0 15.4 17.4 17.4 0.6 0.8 Ratio of alkenyl groups to (meth)acryloyl groups 9.5 0.6 0.3 0.1 15.3 16.2 Ratio of Si-H groups / [(meth)acryloyl groups + alkenyl groups] 1.2 1.3 1.3 1.3 1.4 1.2

[0190] [2] Production of cured products of light- and heat-curable silicone compositions

[0191] [Examples 2-1 to 2-7, Comparative Examples 2-1 to 2-6]

[0192] The light and heat curable silicone compositions obtained in Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-6 were irradiated with a UV-LED lamp having a wavelength of 365 nm at an irradiation intensity of 100 mW / cm at 25° C. under a nitrogen atmosphere. 2 and a dose of 3000mJ / cm 2 The first stage curing was performed by irradiating ultraviolet rays in a manner. The needle penetration or Durometer A hardness of the obtained cured product was measured using a needle penetration meter (1 / 4 cone) or a Durometer A hardness meter manufactured by Rigo Co., Ltd. in accordance with JIS K 6249. In addition, when the needle penetration was less than 1 and could not be measured, the Durometer A hardness was used.

[0193] Next, the cured product obtained by the first step curing was left to stand at 120° C. for 1 hour to perform the second step curing. The cured product was cooled to 25° C. and then the hardness was measured in the same manner as the first step curing product. The results are shown in Tables 3 and 4.

[0194] [Table 3]

[0195]

[0196] [Table 4]

[0197]

[0198] As shown in Tables 3 and 4, it can be seen that the light and heat curable silicone compositions prepared in Examples 1-1 to 1-7 have a large difference in hardness between the first step curing using light and the second step curing using heat.

[0199] On the other hand, in the case of the compositions of Comparative Examples 1-1, 1-5, and 1-6 in which the amount of (meth)acryloyl groups of component (A) was less than 1 mmol in 100 g of the composition, the first-stage curing by light did not occur. In the case of the compositions of Comparative Examples 1-2 to 1-4 in which the amount of (meth)acryloyl groups of component (A) exceeded 15 mmol in 100 g of the composition, it was found that the first-stage curing by light was excessively performed, 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 light- and heat-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 photopolymerization initiator, and (E) a hydrosilylation reaction catalyst, The (meth)acryloyl group contained in the component (A) in 100 g of the composition is 1 to 15 mmol, The ratio of the number of alkenyl groups in the composition to the number of (meth)acryloyl groups contained in the component (A) is 0.5 or more, The ratio of the number of hydrosilyl groups to the number of alkenyl groups and (meth)acryloyl groups contained in the components (A) and (B) is 0.8 to 3.

0.

2. The light- and heat-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 the 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, and r are numbers satisfying p>0, q>0, r>0, and p+q+r=1, respectively, [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 light- and heat-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, 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 each a number satisfying t>0, u>0, v>0 and (t+u+v)=1.

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

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

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