Curable organopolysiloxane composition and release sheet

Abstract

Provided is a curable organopolysiloxane composition comprising the following components (A)-(D). (A) Organopolysiloxane having, per molecule, at least two alkenyl groups which are bonded to silicon. (B) Organohydrogen polysiloxane having, per molecule, two or more hydrogen atoms (SiH groups) which are bonded to a silicon atom. (C) A polybutadiene compound represented by the following general formula (1) where R1 and R2 are each independently an unsubstituted or substituted C1-12 monovalent hydrocarbon group, and each R3 is represented by the following formula (1-1) or (1-2). (D) A catalytic amount of a platinum group metal-based catalyst.

Description

Curable organopolysiloxane composition and release sheet

[0001] The present invention relates to a curable organopolysiloxane composition that provides a cured coating with release properties, and the resulting cured coating exhibits excellent adhesion to a wide range of substrates, particularly paper substrates such as supercalendered kraft paper and clay-coated kraft paper, and the composition is characterized by being able to suppress changes in the release force of the cured product due to the addition of an adhesion promoter. In particular, the present invention relates to an organopolysiloxane composition that exhibits excellent adhesion to various substrates even when a reduced amount of platinum group metal catalyst is used, and to a release sheet having a cured coating of the composition.

[0002] Conventionally, in order to prevent adhesion between substrates such as paper or plastic films and adhesive materials, a cured coating of an organopolysiloxane composition is formed on the surface of the substrate to impart release properties. As a method for forming a cured organopolysiloxane coating on the surface of the substrate, a method for forming a release coating by addition reaction is widely used because it has advantages such as excellent curability and the ability to vary the release properties. In this addition reaction, platinum or another platinum group metal is generally used as a catalyst.

[0003] The cured coating obtained from this addition reaction curable organopolysiloxane composition must be able to be peeled off from adhesive materials such as adhesive tape with a small peeling force, while also being able to adhere to substrates such as paper, plastic film, etc. Cured coatings with poor adhesion can cause problems such as peeling off from the substrate (the cured coating peels off like eraser shavings) several days after formation or when stored under high-temperature, high-humidity conditions.

[0004] It is believed that the adhesion of cured coatings to substrates is due to the SiH groups in the organopolysiloxane composition. The reason for this is that compositions with a low SiH content often have poor adhesion, and in such cases, increasing the SiH content improves adhesion. However, it is known that increasing the SiH content increases the peel strength due to the interaction between the SiH groups and the adhesive material, and it is often difficult to achieve easy peeling while maintaining high adhesion to the substrate.

[0005] Another method for improving the adhesion of an organopolysiloxane composition to a substrate is to subject the surface of the substrate to an adhesion-enhancing treatment or primer treatment, but these methods of treating the surface of the substrate have the disadvantage of requiring additional steps and are therefore not preferred.

[0006] Therefore, methods have been devised to improve adhesion to substrates by adding an adhesion promoter to an organopolysiloxane composition. Patent Documents 1 and 2 describe that adding a specific aryl group-containing organohydrogenpolysiloxane as an adhesion promoter to an addition-curable organopolysiloxane composition containing an alkenyl group-containing organopolysiloxane and an organohydrogenpolysiloxane improves the adhesion of the solventless organopolysiloxane composition to a film substrate. However, because the specific aryl group-containing organohydrogenpolysiloxane is a SiH-containing compound, there is a problem in that the peel force is high.

[0007] Patent Document 3 describes a release composition containing a curable alkenyl silicone having a branched structure and an adhesion promoter for release coatings containing oxirane or epoxide and SiH. This provides excellent adhesion to paper and polymer substrates, particularly PET films, but because this adhesion promoter is also a SiH-containing compound, its addition increases the release force. Patent Document 4 describes an organopolysiloxane having epoxy groups and substantially no SiH groups as an adhesion promoter without SiH groups, added to a silicone composition for forming a cured release coating. The examples in Patent Document 4 describe improved adhesion to PET films and PP films, but do not mention release force.

[0008] Patent Document 5 describes that the adhesion of the resulting cured coating to the substrate is improved by adding a reaction product of a liquid polyorganosiloxane having an alkenyl group and a silanol group with a hydrolyzable silane having an epoxy group as an adhesion promoter to a solventless silicone composition. In particular, the reaction product contains one or more Q units (SiO 4 / 2 ), D units (RSiO 2 / 2) and a plurality of M units (R'R 2 SiO 1 / 2 In the examples, the release coating composition based on a multi-branched siloxane containing a siloxane having multiple branches containing SiO 2 develops good adhesion when combined with an adhesion promoter as described in Patent Document 5, where R and R' are selected from alkyl and alkenyl groups having 1 to 6 carbon atoms, and at least three R' are alkenyl groups. 4 / 2 The document describes a composition that combines a specific organopolysiloxane containing an alkenyl group with an adhesion promoter, but does not mention release force.

[0009] On the other hand, Patent Document 6 discovered that adding a (meth)acrylic group-containing organopolysiloxane compound to an addition-reaction-type organopolysiloxane composition enables the addition reaction with a small amount of platinum group metal catalyst, making it possible to form a cured film with release strength equivalent to that of conventional compositions. Patent Document 7 also uses an organopolysiloxane having two or more silicon-bonded alkenyl groups per molecule and an average of 0.01 to 2.9 (meth)acrylic groups as the base polymer of an addition-reaction-type organopolysiloxane composition, thereby similarly reducing the amount of platinum group metal catalyst used. However, while Patent Documents 6 and 7 describe release strength in their examples, Patent Document 6 makes no mention of adhesion, and Patent Document 7 only mentions adhesion to glassine paper.

[0010] In recent years, supercalendered kraft paper and clay-coated kraft paper have become mainstream paper substrates in Europe and the United States. However, the above-mentioned Patent Documents 1 to 7 make no mention of adhesion to these substrates, and there is a particular need for the development of a curable organopolysiloxane composition that provides a cured coating that has high adhesion to supercalendered kraft paper and clay-coated kraft paper.

[0011] Japanese Patent Application Publication No. 2018-012827 Japanese Patent Application Publication No. 2018-119056 Japanese Patent Application Publication No. 2006-519893 Japanese Patent Application Publication No. 2011-132532 Japanese Patent Application Publication No. 2010-500462 International Publication No. 2020 / 145151 International Publication No. 2021 / 251255

[0012] The present inventors applied release compositions containing the adhesion improvers described in Patent Documents 1 and 2 to various substrates, and found that the adhesion to supercalendered kraft paper and clay-coated kraft paper was insufficient. Furthermore, because these adhesion improvers are SiH-containing compounds, the release force increased. The adhesion improver described in Patent Document 3 improved adhesion to supercalendered kraft paper and clay-coated kraft paper to some extent, but also showed an increase in release force. Furthermore, because the adhesion improvers described in Patent Documents 4 and 5 are not SiH-containing compounds, the change in release force was small, but no improvement in adhesion could be confirmed.

[0013] Furthermore, when the curable organopolysiloxane compositions described in Patent Documents 6 and 7 were applied to various substrates, it was indeed possible to obtain cured coatings with a small amount of platinum group metal catalyst, but the adhesion was insufficient. Moreover, depending on the substrate, adhesion was sometimes lower than with a normal amount of platinum group metal catalyst, and when the amount of platinum group metal catalyst was small, higher adhesion was required.

[0014] In view of the above circumstances, the present invention aims to provide a curable organopolysiloxane composition that produces a cured coating that has excellent adhesion to a wide range of substrates, particularly paper substrates such as supercalendered kraft paper and clay-coated kraft paper, and that minimizes changes in the release force of the cured product due to the addition of an adhesion promoter, as well as a release sheet having a cured coating of this composition. Another object of the present invention is to provide a curable organopolysiloxane composition that produces a cured product that has excellent adhesion to a variety of substrates, even when the amount of platinum group metal catalyst used is reduced.

[0015] As a result of extensive research into achieving the above-mentioned object, the present inventors discovered that by adding a polybutadiene compound represented by the general formula (1) described below to a curable organopolysiloxane composition, it is possible to obtain a cured coating that has excellent adhesion to a wide range of substrates, particularly to paper substrates such as supercalendered kraft paper and clay-coated kraft paper, while suppressing changes in the release force of the cured product that would otherwise occur due to the addition of an adhesion promoter, and thus completed the present invention.

[0016] Accordingly, the present invention provides the following curable organopolysiloxane composition and release sheet: 1. A curable organopolysiloxane composition comprising the following components (A) to (D): (A) 100 parts by mass of an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule, (B) an organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms (SiH groups) per molecule, in an amount such that the ratio of the number of SiH groups in component (B) to the number of alkenyl groups in component (A) is 0.5 to 10, and (C) a compound represented by the following general formula (1): [In the formula, R 1 , R 2 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and R 3 are represented by the following formula (1-1) or (1-2), respectively: (In the formula, R 5 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and n is a positive number from 1 to 100. An asterisk * indicates a bond to —CH— in the main chain. 4are each independently a hydrogen atom or a group represented by -CH2CH2OH, a is a positive number that satisfies 0 < a ≦ 120, b is 0 or a positive number that satisfies 0 < b ≦ 100, c is 0 or a positive number that satisfies 0 < c ≦ 100, d is 0 or a positive number that satisfies 0 < d ≦ 20, and 0 < b + c ≦ 200, and m is an integer from 1 to 3, provided that the order of the respective repeating units is arbitrary.] A polybutadiene compound represented by the formula: 0.01 to 10 parts by mass per 100 parts by mass of component (A), and (D) a platinum group metal catalyst: a catalytic amount. 2. The curable organopolysiloxane composition according to 1, wherein the number average molecular weight of the polybutadiene compound of component (C) is 1,000 to 1,000,000. 3. 3. The curable organopolysiloxane composition according to 1 or 2, wherein the polybutadiene compound of component (C) independently satisfies the following conditions of formulas (i), (ii), and (iii) in a, b, c, and d in general formula (1): 0.05≦c / (a+b+c+d)<1.0 (i) 0.1≦c / (b+c)≦1.0 (ii) 0.05≦(b+c) / (a+b+c+d)≦0.95 (iii). 4. The curable organopolysiloxane composition according to any one of 1 to 3, wherein component (A) is an organopolysiloxane represented by formula (2) below. (R 6 3SiO 1 / 2 ) e (R 6 2SiO 2 / 2 ) f (R 6 SiO 3 / 2 ) g (SiO 4 / 2 ) h (2) (wherein, R 6 are each independently a group selected from an alkenyl group having 2 to 12 carbon atoms, a hydroxyl group, and an unsubstituted or substituted monovalent hydrocarbon group that does not have an aliphatic unsaturated bond, and R 6at least two of the groups are alkenyl groups, e is 2 or greater, f is 0 or 0<f, g is 0 or 0<g, and h is a positive number of 0 or 0<h, and e+f+g+h is selected so that the viscosity at 25°C is 1 mPa·s or greater and the viscosity of a 30% by mass toluene solution is 70,000 mPa·s or less.) 5. The curable organopolysiloxane composition according to any one of 1 to 3, wherein component (A) is an organopolysiloxane represented by the following formula (3): (R 7 3SiO 1 / 2 ) v (R 7 2SiO 2 / 2 ) w (R 7 SiO 3 / 2 ) x (SiO 4 / 2 ) y (3) (wherein, R 7 are each independently a group selected from an alkenyl group having 2 to 12 carbon atoms, a hydroxyl group, an unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond, and a (meth)acrylic group-containing group; R 7 At least two of R are alkenyl groups; 7 of which 0.01 to 2.9 are (meth)acrylic group-containing groups, v is 2 or greater, w is 8 or greater, x is 0 or a positive number satisfying 0<x, y is 0 or a positive number satisfying 0<y, and v+w+x+y is selected so that the viscosity at 25°C is 1 mPa·s or greater and the viscosity of a 30% by mass toluene solution is 70,000 mPa·s or less.) 6. A curable organopolysiloxane composition according to any one of 1 to 5, wherein component (B) is represented by the following average composition formula (4): R 8 t H u SiO (4-t-u) / 2 (4) (wherein, R 8are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and containing no aliphatic unsaturated bonds, and t and u are positive numbers satisfying 0.7≦t≦2.1, 0.001≦u≦1.0, and 0.8≦t+u≦3.0, with the proviso that component (B) has at least two hydrogen atoms bonded to silicon atoms.) 7. The curable organopolysiloxane composition according to any one of 1 to 6, further comprising 0.01 to 20 parts by mass per 100 parts by mass of component (A) of (E) an organopolysiloxane represented by the following formula (5) and having 0.1 to 20 (meth)acrylic group-containing groups bonded to silicon atoms per molecule: (R 9 3SiO 1 / 2 ) p (R 9 2SiO 2 / 2 ) q (R 9 SiO 3 / 2 ) r (SiO 4 / 2 ) s (5) (wherein, R 9 are each independently a group selected from an alkenyl group having 2 to 12 carbon atoms, a hydroxyl group, an unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond, and a (meth)acrylic group-containing group; R 9 Among these, 0.1 to 20 are (meth)acrylic group-containing groups, and p to s are positive numbers that satisfy the following conditions: 2≦p≦202, 5≦q≦1,000, 0 or 0<r≦100, and 0 or 0<s≦100, with the proviso that 0≦r+s≦100. 8. A release sheet comprising a substrate and a release agent layer provided on at least one surface of the substrate, wherein the release agent layer is formed from a cured product obtained by curing the curable organopolysiloxane composition described in any one of 1 to 7.

[0017] The curable organopolysiloxane composition of the present invention can provide a cured coating that exhibits excellent adhesion to a wide range of substrates, particularly paper substrates such as supercalendered kraft paper and clay-coated kraft paper, while suppressing changes in the release force of the cured product due to the addition of an adhesion promoter, making it particularly useful as a release sheet for adhesive materials.

[0018] The present invention will be described in more detail below. [Component (A)] Component (A) is an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule, and can be used alone or in combination of two or more. Component (A) has at least two silicon-bonded alkenyl groups per molecule. If there are fewer than two, there is a high possibility that uncrosslinked molecules will remain after curing, resulting in reduced curability. More specifically, the content of silicon-bonded alkenyl groups is preferably 0.001 mol / 100g or more from the viewpoint of curability. However, because the peel strength may be too high, making the adhesive material difficult to peel, the content is preferably 0.7 mol / 100g or less, more preferably 0.0015 to 0.6 mol / 100g, and even more preferably 0.002 to 0.5 mol / 100g.

[0019] The viscosity of component (A) at 25°C is preferably from 1 mPa·s to 70,000 mPa·s in a 30% by weight toluene solution, more preferably from 4 mPa·s to 60,000 mPa·s in a 30% by weight toluene solution, and even more preferably from 7 mPa·s to 50,000 mPa·s in a 30% by weight toluene solution. If the viscosity of component (A) is lower than the above lower limit, the composition may wet and spread too easily, resulting in an insufficient coating amount on the substrate surface. On the other hand, if the viscosity is higher than the above upper limit, the composition may wet and spread less easily, resulting in reduced workability. In the present invention, all viscosities are values ​​measured at 25°C using a rotational viscometer, using rotors No. 1 to 4 and rotation speeds ranging from 3 to 60 rpm, as appropriate, depending on the viscosity. The term "30% by weight toluene solution viscosity" refers to the viscosity of a solution obtained by dissolving 30% by weight of organopolysiloxane in toluene.

[0020] Examples of the component (A) include organopolysiloxanes represented by the following formula (2): (R 6 3SiO 1 / 2 ) e (R 6 2SiO 2 / 2 ) f (R 6 SiO 3 / 2 ) g (SiO 4 / 2 ) h(2) (wherein, R 6 are each independently a group selected from an alkenyl group having 2 to 12 carbon atoms, a hydroxyl group, and an unsubstituted or substituted monovalent hydrocarbon group that does not have an aliphatic unsaturated bond, and R 6 at least two of the groups are alkenyl groups, e is 2 or more, f is 0 or 0<f (f is 0 or more), g is 0 or 0<g (g is 0 or more), and h is a positive number of 0 or 0<h (h is 0 or more), and e+f+g+h is selected so that the viscosity at 25°C is 1 mPa·s or more and 70,000 mPa·s or less when dissolved in 30% by mass toluene.

[0021] In the above formula (2), examples of alkenyl groups having 2 to 12 carbon atoms include vinyl, allyl, butenyl, propenyl, 5-hexenyl, octenyl, and decenyl groups. Among these, vinyl is preferred from an industrial viewpoint. The unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond preferably has 1 to 12 carbon atoms, and preferably 1 to 10 carbon atoms. Examples of monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, butyl, and octyl groups; cycloalkyl groups such as cyclohexyl groups; aryl groups such as phenyl, tolyl, xylyl, and naphthyl groups; and aralkyl groups such as benzyl and phenethyl groups. Examples of such monovalent hydrocarbon groups include haloalkyl groups in which some or all of the hydrogen atoms in these groups have been substituted with halogen atoms, such as chloropropyl and trifluoropropyl groups. From the viewpoint of high curability and low peel strength, it is preferable to use a monovalent hydrocarbon group in which all R 6 Preferably, 80 mol % or more of the groups are methyl groups.

[0022] e is a positive number of 2 or more, f is 0 or 0<f, g is 0 or 0<g, and h is a positive number of 0 or 0<h, and e+f+g+h are selected so that the viscosity at 25°C is 1 mPa·s or more and 70,000 mPa·s or less in a 30% by mass toluene solution. e is preferably a positive number of 2 to 300, f is preferably a positive number of 60 to 20,000, g is more preferably 0 or a positive number satisfying 0<g≦100, and h is more preferably 0 or a positive number satisfying 0<h≦100. 10≦e+f+g+h≦20,000 is preferred, and 60≦e+f+g+h≦15,000 is more preferred.

[0023] Examples of organopolysiloxanes represented by formula (2) include compounds represented by the following formula: (R 6 3SiO 1 / 2 ) 2 (R 6 2SiO 2 / 2 ) f (R 6 3SiO 1 / 2 ) e (R 6 2SiO 2 / 2 ) f (R 6 SiO 3 / 2 ) g (R 6 3SiO 1 / 2 ) e (R 6 2SiO 2 / 2 ) f (SiO 4 / 2 ) h (R 6 3SiO 1 / 2 ) e (R 6 2SiO 2 / 2 ) f (R 6 SiO 3 / 2 ) g (SiO 4 / 2 ) h In each of the above formulas, R 6 , e to h are as described above.

[0024] More specific examples include, but are not limited to, compounds represented by the following formula: (ViMeSiO 1 / 2 )2(Me2SiO 2 / 2 ) α1 (1≦α1≦19,998) (Vi3SiO 1 / 2 )2(Me2SiO 2 / 2 ) α2 (1≦α2≦19,998) (ViMe2SiO 1 / 2 )2(Me2SiO 2 / 2 ) α3 (ViMeSiO 2 / 2 ) α4 (0≦α3≦19,997, 1≦α4≦2,000, 1≦α3+α4≦19,998) (ViMe2SiO 1 / 2)2(Me2SiO 2 / 2 ) α5 (PhSiO 2 / 2 ) α6 (0≦α5≦19,997, 1≦α6≦2,000, 1≦α5+α6≦19,998) (ViMe2SiO 1 / 2 )2(Me2SiO 2 / 2 ) α7 (ViMeSiO 2 / 2 ) α8 (PhSiO 2 / 2 ) α9 (0≦α7≦19,996, 1≦α8≦2,000, 1≦α9≦2,000, 2≦α7+α8+α9≦19,998) (ViMe2SiO 1 / 2 ) α10 (MeSiO 2 / 2 ) α11 (MeSiO 3 / 2 ) α12 (3≦α10≦102, 0≦α11≦19,996, 1≦α12≦100, 4≦α10+α11+α12≦20,000) (ViMe2SiO 1 / 2 ) α13 (MeSiO 2 / 2 ) α14 (MeSiO 3 / 2 ) α15 (SiO 4 / 2 ) α16 (4≦α13≦302, 0≦α14≦19,995, 0≦α15≦100, 1≦α16≦100, 5≦α13+α14+α15+α16≦20,000) In the above formulas, Me, Vi, and Ph represent a methyl group, a vinyl group, and a phenyl group, respectively.

[0025] In the present invention, by incorporating the below-described component (E) or by using an organopolysiloxane represented by the below-described formula (3) as component (A), it is possible to use a reduced amount of the platinum group metal catalyst of component (D) (hereinafter sometimes referred to as low platinum). Component (E) and the organopolysiloxane represented by the below-described formula (3) are components that have the effect of increasing the reactivity of the addition reaction in the present invention. The reason for the increased reactivity is not clear, but it is presumed that the above effect is exhibited by the (meth)acrylic group-containing group being coordinated in some way to the platinum group metal atom. (R 73SiO 1 / 2 ) v (R 7 2SiO 2 / 2 ) w (R 7 SiO 3 / 2 ) x (SiO 4 / 2 ) y (3) (wherein, R 7 are each independently a group selected from an alkenyl group having 2 to 12 carbon atoms, a hydroxyl group, an unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond, and a (meth)acrylic group-containing group; R 7 At least two of R are alkenyl groups; 7 Among these, 0.01 to 2.9 are (meth)acrylic group-containing groups, v is 2 or more, w is 8 or more, x is 0 or a positive number satisfying 0<x (x is 0 or more), and y is a positive number satisfying 0 or 0<y (y is 0 or more), and v+w+x+y is selected so that the viscosity at 25°C is 1 mPa s or more and 70,000 mPa s or less when dissolved in 30% by mass toluene.

[0026] In the above formula (3), examples of the alkenyl group include the same alkenyl groups as those specifically exemplified as the alkenyl groups in the above formula (2), and among these, from an industrial viewpoint, a vinyl group is preferred. In the above formula (3), examples of the unsubstituted or substituted monovalent hydrocarbon group having 2 to 12 carbon atoms and no aliphatic unsaturated bond include the same unsubstituted or substituted monovalent hydrocarbon group having 2 to 12 carbon atoms and no aliphatic unsaturated bond in the above formula (2). Among these, in order to increase the curability and reduce the release force, it is preferable to use a group in which all R 7 Preferably, 80 mol % or more of the groups are methyl groups.

[0027] The organopolysiloxane represented by the formula (3) has 0.01 to 2.9 silicon-bonded (meth)acrylic group-containing groups per molecule. 7Of these, 0.01 to 2.9 are (meth)acrylic group-containing groups. By setting the number to 0.01 or more, the reactivity of the addition reaction can be further increased, and by setting the number to 2.9 or less, a more appropriate peel force can be obtained. More specifically, the content of (meth)acrylic group-containing groups bonded to silicon is preferably 0.0001 to 0.1 mol / 100 g, more preferably 0.0003 to 0.08 mol / 100 g, and even more preferably 0.0005 to 0.05 mol / 100 g. By setting the content of (meth)acrylic group-containing groups to the above range or above, the reactivity of the addition reaction can be further increased, while by setting the content to the above upper limit or less, a more appropriate peel force can be obtained.

[0028] Examples of the (meth)acrylic group-containing group include CH═CR 10 COR 11 - (wherein, R 10 is a hydrogen atom or a methyl group, and R 11 is OR 12 (R 12 is a divalent organic group having 1 to 20 carbon atoms) or R 12 ) is a divalent group represented by the formula:

[0029] R 10 is a hydrogen atom or a methyl group, and preferably a hydrogen atom. 11 is OR 12 (R 12 is a divalent organic group having 1 to 20 carbon atoms) or R 12 is a divalent group represented by OR 12 is preferred. 12 R is a divalent organic group having 1 to 20 carbon atoms, which may have a branched or cyclic structure, and may contain an epoxy group, an ester bond, a urethane bond, an ether bond, an isocyanate bond, or a hydroxyl group. 12Examples of R include divalent hydrocarbon groups such as linear alkylene groups such as methylene, ethylene, propylene, butylene, hexamethylene, octamethylene, and decylene, branched alkylene groups such as methylethylene and methylpropylene, cyclic alkylene groups such as cyclohexylene, alkenylene groups such as propenylene, arylene groups such as phenylene, and aralkylene groups such as methylenephenylene and methylenephenylenemethylene. The divalent hydrocarbon group may be interposed by an ester bond, a urethane bond, an ether bond, or an isocyanate bond, and these may also be used in combination. Furthermore, some or all of the hydrogen atoms of these divalent hydrocarbon groups may be substituted with epoxy groups or hydroxyl groups. Among these, R 12 A propylene group is preferred as the alkyl group. Among them, a group represented by CH2=CHCOOC3H6- is preferred from the viewpoint of increasing reactivity.

[0030] v is 2 or greater, w is 8 or greater, x is 0 or a positive number satisfying 0<x, and y is 0 or a positive number satisfying 0<y, and v+w+x+y is selected so that the viscosity at 25°C is 1 mPa s or greater and 70,000 mPa s or less when dissolved in 30% by mass toluene. v is preferably a positive number from 2 to 300, w is preferably a positive number from 60 to 20,000, x is preferably 0 or a positive number satisfying 0<x≦100, and y is preferably 0 or a positive number satisfying 0<y≦100, with 10≦v+w+x+y≦20,000 being preferred, and 60≦v+w+x+y≦15,000 being more preferred.

[0031] Examples of organopolysiloxanes represented by the above formula (3) include compounds represented by the following formula: (R 7 3SiO 1 / 2 ) 2 (R 7 2SiO 2 / 2 ) w (R 7 3SiO 1 / 2 ) v (R 7 2SiO 2 / 2 ) w (R 7 SiO 3 / 2 ) x (R 7 3SiO 1 / 2 ) v(R 7 2SiO 2 / 2 ) w (SiO 4 / 2 ) y (R 7 3SiO 1 / 2 ) v (R 7 2SiO 2 / 2 ) w (R 7 SiO 3 / 2 ) x (SiO 4 / 2 ) y In each of the above formulas, R 7 , v to y are as described above.

[0032] More specific examples include, but are not limited to, compounds represented by the following formula: (ViMeSiO 1 / 2 )2(Me2SiO 2 / 2 ) γ1 (AMeSiO) γ2 (5.1≦γ1<20,000, 0.01≦γ2≦2.9, 8≦γ1+γ2≦19,998) (Vi3SiO 1 / 2 )2(Me2SiO 2 / 2 ) γ3 (AMeSiO 2 / 2 ) γ4 (5.1≦γ3<20,000, 0.01≦γ4≦2.9, 8≦γ3+γ4≦19,998) (ViMe2SiO 1 / 2 )2(Me2SiO 2 / 2 ) γ5 (ViMeSiO 2 / 2 ) γ6 (AMeSiO 2 / 2 ) γ7 (0≦γ5<19,997, 1≦γ6≦2,000, 0.01≦γ7≦2.9, 8≦γ5+γ6+γ7≦19,998) (ViMe2SiO 1 / 2 )2(Me2SiO 2 / 2 ) γ8 (PhSiO 2 / 2 ) γ9 (AMeSiO 2 / 2 ) γ10 (0≦γ8<19,997, 1≦γ9≦2,000, 0.01≦γ10≦2.9, 8≦γ8+γ9+10≦19,998) (ViMe2SiO 1 / 2 )2(Me2SiO 2 / 2 ) γ11 (ViMeSiO 2 / 2 ) γ12 (PhSiO 2 / 2 ) γ13 (AMeSiO 2 / 2 ) γ14 (0≦γ11<19,996, 1≦γ12≦2,000, 1≦γ13≦2,000, 8≦γ11+γ12+γ13+γ14≦19,998) (ViMe2SiO 1 / 2 ) γ15 (MeSiO 2 / 2 ) γ16 (AMeSiO 2 / 2 ) γ17 (MeSiO 3 / 2 ) γ18 (3≦γ15≦102, 5.1≦γ16<19,996, 0.01≦γ17≦2.9, 8≦γ16+γ17≦19,996, 1≦γ18≦100, 12≦γ15+γ16+γ17+γ18≦20,000) (ViMe2SiO 1 / 2 ) γ19 (MeSiO 2 / 2 ) γ20 (AMeSiO 2 / 2 ) γ21 (MeSiO 3 / 2 ) γ22 (SiO 4 / 2 ) γ23 (4≦γ19≦302, 5.1≦γ20<19,995, 0.01≦γ21≦2.9, 8≦γ20+γ21≦19,995, 0≦γ22≦100, 1≦γ23≦100, 13≦γ19+γ20+γ21+γ22+γ23≦20,000) In each of the above formulas, Me, Vi, Ph, and A respectively represent a methyl group, a vinyl group, a phenyl group, and a group represented by CH2=CHCOOC3H6-.

[0033] In the present invention, as component (A), the organopolysiloxane represented by formula (2) and the organopolysiloxane represented by formula (3) may be used alone or in combination, with the number of alkenyl groups and viscosity being as described above.

[0034] [Component (B)] Component (B) is an organohydrogenpolysiloxane containing two or more silicon-bonded hydrogen atoms (SiH groups) per molecule, and can be used alone or in combination of two or more. The SiH groups undergo an addition reaction with the alkenyl groups of component (A) to form a cured coating.

[0035] Component (B) has at least two SiH groups per molecule. If there are fewer than two, there is a high possibility that uncrosslinked molecules will remain after curing, resulting in reduced curability. More specifically, the SiH group content is preferably 0.5 mol / 100g or more from the viewpoint of curability, and is preferably 2.0 mol / 100g or less from the viewpoint of excessively high peel strength. It is more preferably 0.6 to 1.8 mol / 100g, and even more preferably 0.8 to 1.6 mol / 100g.

[0036] The viscosity of component (B) at 25° C. is preferably 2 to 200 mPa·s, more preferably 5 to 180 mPa·s, and even more preferably 10 to 150 mPa·s. By setting the viscosity of component (B) to the above lower limit or more, adhesion to the substrate is further improved, and by setting the viscosity to the above upper limit or less, reactivity is further improved.

[0037] Examples of component (B) include organohydrogenpolysiloxanes represented by the following average composition formula (4): 8 t H u SiO (4-t-u) / 2 (4) (wherein, R 8 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and containing no aliphatic unsaturated bonds, and t and u are positive numbers satisfying the conditions 0.7≦t≦2.1, 0.001≦u≦1.0, and 0.8≦t+u≦3.0, with the proviso that component (B) has at least two hydrogen atoms bonded to silicon atoms.

[0038] In the above formula (4), R 8are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12, preferably 1 to 10, carbon atoms and no aliphatic unsaturated bond, and examples thereof include alkyl groups such as methyl, ethyl, propyl, butyl, and octyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl and phenethyl; and monovalent hydrocarbon groups in which some or all of the hydrogen atoms bonded to carbon atoms of these groups have been substituted with hydroxy groups, halogen atoms, alkoxysilyl groups, polyoxyalkylene groups, epoxy groups, carboxyl groups, or the like. 8 As the alkyl group, an alkyl group is preferable, and a methyl group is more preferable. 8 It is preferable that 50 mol % or more, typically 60 to 100 mol % of the total R be methyl groups. 8 If the amount is less than 50 mol %, the compatibility with component (A) may be poor, and the curable organopolysiloxane composition may become cloudy or undergo phase separation.

[0039] The values ​​of t and u satisfy the following conditions: 0.7≦t≦2.1, preferably 0.8≦t≦2.1, and more preferably a positive number satisfying 1.0≦t≦2.0. 0.001≦u≦1.0, more preferably 0.005≦u≦1.0, and even more preferably a positive number satisfying 0.01≦u≦0.98. 0.8≦t+u≦3.0, preferably 1.0≦t+u≦2.8, and more preferably a positive number satisfying 1.3≦t+u≦2.5. However, component (B) has at least two hydrogen atoms bonded to silicon atoms.

[0040] Examples of the organohydrogenpolysiloxane (B) include siloxanes containing hydrogensilyl groups at both ends, siloxanes containing hydrogensilyl groups in the side chain, siloxanes containing hydrogensilyl groups at one end and in the side chain, and siloxanes containing hydrogensilyl groups at both ends and in the side chain. More specifically, the following organohydrogenpolysiloxanes are exemplified, but are not limited to these. The bonding order of the siloxane units shown in parentheses is not limited to the following: (MeSiO 1 / 2)2(MeHSiO) δ1 (2≦δ1≦200) (Me2SiO 1 / 2 )2(MeHSiO 2 / 2 ) δ2 (MeSiO 2 / 2 ) δ3 (2≦δ2≦199, 1≦δ3≦198, 3≦δ2+δ3≦200) (Me2SiO 1 / 2 ) δ4 (MeHSiO 2 / 2 ) δ5 (MeSiO 2 / 2 ) δ6 (MeSiO 3 / 2 ) δ7 (3≦δ4≦52, 2≦δ5≦200, 0≦δ6≦198, 2≦δ5+δ6≦200, 1≦δ7≦50) (Me2SiO 1 / 2 ) δ8 (MeHSiO 2 / 2 ) δ9 (MeSiO 2 / 2 ) δ10 (MeSiO 3 / 2 ) δ11 (SiO 4 / 2 ) δ12 (4≦δ8≦102, 2≦δ9≦200, 0≦δ10≦198, 2≦δ9+δ10≦200, 0≦δ11≦50, 1≦δ12≦50, 1≦δ11+δ12≦50) In the above formulae, Me and H represent a methyl group and a hydrogen atom, respectively.

[0041] The amount of component (B) is such that the ratio of the number of SiH groups in component (B) to the number of alkenyl groups in component (A) is 0.5 to 10, preferably 0.8 to 8.0, and more preferably 1.0 to 5.0. If the amount of component (B) is less than the above-mentioned lower limit, curability will be insufficient, and if it exceeds the above-mentioned upper limit, the number of remaining SiH groups will increase, causing problems such as excessively high release force.

[0042] [Component (C)] The polybutadiene compound of component (C) is a characteristic compound of the present invention. Adding component (C) as an adhesion promoter to a curable organopolysiloxane composition can improve adhesion to a wide range of substrates, particularly paper substrates such as supercalendered kraft paper and clay-coated kraft paper. Furthermore, because it is a compound that does not contain SiH groups, it is characterized by minimal change in release force due to its addition. Component (C) is a polybutadiene compound represented by the following general formula (1), and can be used alone or in combination of two or more types: [In the formula, R 1 , R 2 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and R 3 are represented by the following formula (1-1) or (1-2), respectively: (In the formula, R 5 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and n is a positive number from 1 to 100. An asterisk * indicates a bond to —CH— in the main chain. 4 are each independently a hydrogen atom or a group represented by -CHCHOH, a is a positive number satisfying 0 < a ≦ 120, b is 0 or a positive number satisfying 0 < b ≦ 100, c is 0 or a positive number satisfying 0 < c ≦ 100, d is 0 or a positive number satisfying 0 < d ≦ 20, and satisfies 0 < b + c ≦ 200, and m is an integer of 1 to 3, provided that the order of the respective repeating units is arbitrary.] These polybutadiene compounds can be used singly or in combination of two or more.

[0043] R 1 , R 2are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, and dodecyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; vinyl, allyl, propenyl, isopropenyl, and butenyl. Examples include alkenyl groups such as a phenyl group, a pentenyl group, and a hexenyl group; aryl groups such as a phenyl group, a tolyl group, a xylyl group, and an α- or β-naphthyl group; aralkyl groups such as a benzyl group, a 2-phenylethyl group, and a 3-phenylpropyl group; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as F, Cl, or Br, or with a cyano group, for example, a 3-chloropropyl group, a 3,3,3-trifluoropropyl group, and a 2-cyanoethyl group. Among these, alkyl groups having 1 to 10 carbon atoms or aryl groups having 6 to 10 carbon atoms are preferred, alkyl groups such as a methyl group and an ethyl group are more preferred, and a methyl group is even more preferred.

[0044] R 3 are represented by the following formula (1-1) or (1-2), respectively: (In the formula, R 5 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and n is a positive number from 1 to 100. An asterisk * indicates a bond to —CH— in the main chain.) is a group represented by the following formula. By containing a group represented by formula (1-1), adhesion to a substrate can be further improved, and by containing a group represented by formula (1-2), compatibility with components (A) and (B) can be improved.

[0045] R 5 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and R 1 , R 2 Examples of n include those similar to those shown in the above, with a methyl group being preferred. n is a positive number from 1 to 100, and from the viewpoint of compatibility with components (A) and (B), a positive number from 4 to 100 is preferred, and a positive number from 8 to 100 is more preferred. R 4are each independently a hydrogen atom or a group represented by —CH2CH2OH, and a hydrogen atom is preferred.

[0046] The number average molecular weight of component (C) is preferably 1,000 to 1,000,000, more preferably 1,500 to 100,000, and even more preferably 2,000 to 10,000. By setting the number average molecular weight to 1,000 or more, adhesion to the substrate is further improved. On the other hand, if it exceeds 1,000,000, the viscosity may become too high, which may reduce workability. The number average molecular weight (or degree of polymerization) can be determined as the polystyrene-equivalent number average molecular weight (or number average degree of polymerization) by gel permeation chromatography (GPC) analysis using toluene as a developing solvent (the same applies hereinafter).

[0047] a is a positive number satisfying 0<a≦120, preferably a positive number from 1 to 80, more preferably a positive number from 1 to 60, and even more preferably a positive number from 1 to 40. b is a positive number satisfying 0 or 0<b≦100 (0≦b≦100), preferably a positive number from 0 to 70, more preferably a positive number from 0 to 40, and even more preferably a positive number from 1 to 20. c is a positive number satisfying 0 or 0<c≦100 (0≦c≦100), preferably a positive number from 1 to 70, more preferably a positive number from 2 to 40, and even more preferably a positive number from 3 to 20. d is a positive number satisfying 0 or 0<d≦20 (0≦d≦20), preferably a positive number from 0 to 15, more preferably a positive number from 0 to 10, and even more preferably a positive number from 0 to 5. The expression 0<b+c≦200 is satisfied, and a positive number of 1 to 80 is preferable, a positive number of 5 to 50 is more preferable, and a positive number of 10 to 20 is even more preferable. m is an integer of 1 to 3, and an integer of 2 or 3 is preferable.

[0048] The component (C) preferably satisfies the following conditions of formulas (i), (ii), and (iii): 0.05≦c / (a+b+c+d)<1.0 (i) 0.1≦c / (b+c)≦1.0 (ii) 0.05≦(b+c) / (a+b+c+d)≦0.95 (iii), and more preferably satisfies all of the above.

[0049] 0.05≦c / (a+b+c+d)<1.0 (i) As shown in the above formula, (i) indicates the proportion of hydrolyzable silyl groups contained, and indicates that units containing hydrolyzable silyl groups are contained in an amount of 5 mol% or more per total unit. c / (a+b+c+d) is preferably 0.07 or more, more preferably 0.10 or more. By setting c / (a+b+c+d) to 0.05 or more, adhesion is further improved regardless of the type of substrate. c / (a+b+c+d) is preferably 0.07 to 0.90, more preferably 0.10 to 0.60, and even more preferably 0.10 to 0.30.

[0050] 0.1≦c / (b+c)≦1.0 (ii) As shown in the above formula, this indicates that the content of units containing hydrolyzable silyl groups is 10 mol% or more relative to the sum of units containing hydrolyzable silyl groups and units containing terminal vinyl groups. c / (b+c) is preferably 0.15 or more, more preferably 0.20 or more. By making c / (b+c) 0.1 or more, adhesion is further improved regardless of the type of substrate. c / (b+c) is preferably 0.10 to 1.0, more preferably 0.15 to 0.80, and even more preferably 0.20 to 0.50.

[0051] 0.05≦(b+c) / (a+b+c+d)≦0.95 (iii) (b+c) / (a+b+c+d) is preferably 0.10 to 0.60, more preferably 0.20 to 0.30.

[0052] d / (a+b+c+d) is preferably from 0.006 to 0.3, more preferably from 0.008 to 0.2, and even more preferably from 0.01 to 0.1.

[0053] The amount of component (C) is 0.01 to 10 parts by mass, preferably 0.03 to 8 parts by mass, more preferably 0.05 to 6 parts by mass, and particularly preferably 0.2 to 4 parts by mass, per 100 parts by mass of component (A). If the amount of component (C) is less than the above-mentioned lower limit, the effect of improving adhesion to the substrate will be insufficient. On the other hand, if the amount of component (C) exceeds the above-mentioned upper limit, the peel force may be too high, making it difficult to peel the PSA material, or curability may be reduced.

[0054] The polybutadiene compound (C) is represented by the following general formula (I): (Wherein a, b, c, d, and R 3 , R 4 is the same as above.) and a polybutadiene compound containing a repeating unit having a 1,2-vinyl structure (terminal vinyl group) represented by the following general formula (II): (In the formula, R 1 , R 2 and m are the same as above.) 1 It can be obtained by hydrosilylation of an organosilicon compound such as an organohydrogensilane having a silicon atom-bonded hydrogen atom (SiH group) in the molecule with a platinum compound-containing catalyst and a co-catalyst. In the above general formula (I), a, b, c, and d are the same as above, and (b+c) / (a+b+c+d) is also preferably 0.05 to 0.95, more preferably 0.10 to 0.60, and even more preferably 0.20 to 0.30.

[0055] The number-average molecular weight of the polybutadiene compound represented by the general formula (I) is preferably 100 to 10,000, more preferably 500 to 8,000. The polybutadiene compound represented by the general formula (I) contains repeating units having a 1,2-vinyl structure and repeating units having a 2,3-vinyl structure (trans 1,4 structure) as isomers. The repeating units having a 1,2-vinyl structure are contained in an amount of 5 mol% or more, preferably 7 mol% or more, and more preferably 10 mol% or more. By ensuring that the 1,2-vinyl structure is 5 mol% or more, a decrease in the silane modification rate is suppressed, and the compound can be more effective as an adhesion improver regardless of the type of substrate. There is no particular upper limit on the content of repeating units having a 1,2-vinyl structure, but it is usually 98 mol% or less, preferably 95 mol% or less. The sum of the repeating units having a 1,2-vinyl structure and the repeating units having a 2,3-vinyl structure is 100 mol%.

[0056] As polybutadiene compounds represented by the above general formula (I), NISSO-PB B-1000, NISSO-PB B-2000, NISSO-PB B-3000 (all manufactured by Nippon Soda Co., Ltd.), Ricon 130, Ricon 131, Ricon 134, Ricon 142, Ricon 150, Ricon 152, Ricon 153, Ricon 154, Ricon 156, Ricon 157 (all manufactured by Cray Valley), and LBR-302, LBR-307, LBR-305, LBR-300, LBR-352, LBR-361 (all manufactured by Kuraray Co., Ltd.) are commercially available. In addition, copolymers in which a part of the 1,2-vinyl structure is epoxidized, such as Ricon 130 (manufactured by Cray Valley), copolymers in which a part of the 1,2-vinyl structure is epoxidized, and copolymers in which a part of the 1,2-vinyl structure is substituted with a compound represented by the following general formula (III): (In the formula, R 5 and n are the same as above.) Copolymers obtained by addition reaction of organohydrogenpolysiloxanes represented by the following formula (I) can also be used.

[0057] Examples of the organosilicon compound represented by the general formula (II) include hydrogenalkoxysilanes such as trimethoxysilane, methyldimethoxysilane, dimethylmethoxysilane, triethoxysilane, methyldiethoxysilane, and dimethylethoxysilane. In particular, trimethoxysilane, methyldimethoxysilane, and dimethylmethoxysilane are preferred because of their high hydrolysis property, and trimethoxysilane is more preferred.

[0058] The reaction ratio of the polybutadiene compound represented by the general formula (I) and the organosilicon compound represented by the general formula (II) is preferably 10 to 400 parts by mass of the organosilicon compound represented by the general formula (II) per 100 parts by mass of the polybutadiene compound represented by the general formula (I). Furthermore, the reaction is preferably carried out in such a range that the ratio of SiH groups in the organosilicon compound represented by the general formula (II) to vinyl groups in the repeating units having a 1,2-vinyl structure of the polybutadiene compound represented by the general formula (I) is preferably 0.1 to 1.0 mol / mol, more preferably 0.2 to 1.0 mol / mol.

[0059] The platinum compound-containing catalyst is not particularly limited, but specific examples include chloroplatinic acid, an alcohol solution of chloroplatinic acid, a toluene or xylene solution of a platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex, tetrakistriphenylphosphine platinum, dichlorobistriphenylphosphine platinum, dichlorobisacetonitrile platinum, dichlorobisbenzonitrile platinum, dichlorocyclooctadiene platinum, platinum-carbon, platinum-alumina, platinum-silica, and other supported catalysts. From the viewpoint of selectivity, zero-valent platinum complexes are preferred, and a toluene or xylene solution of a platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex is preferred.

[0060] The amount of platinum compound-containing catalyst used is not particularly limited, but from the viewpoint of reactivity and productivity, the amount of platinum atoms contained is preferably 1×10 per mole of the organosilicon compound represented by general formula (II). -7 ~1 x 10 -2 mol is preferred, and 1×10 -7 ~1 x 10 -3 Molar ranges are more preferred.

[0061] Examples of the promoter include ammonium salts of inorganic acids, acid amide compounds, carboxylic acids, etc. Examples of ammonium salts of inorganic acids include ammonium chloride, ammonium sulfate, ammonium amidosulfate, ammonium nitrate, monoammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium diphosphite, ammonium carbonate, ammonium hydrogen carbonate, ammonium sulfide, ammonium borate, and ammonium fluoroborate, and ammonium salts of inorganic acids having a pKa of 2 or more are preferred, with ammonium carbonate and ammonium hydrogen carbonate being particularly preferred.

[0062] Examples of the acid amide compound include formamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, acrylamide, malonamide, succinamide, maleamide, fumaramide, benzamide, phthalamide, palmitic acid amide, and stearic acid amide.

[0063] Examples of carboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, methoxyacetic acid, pentanoic acid, caproic acid, heptanoic acid, octanoic acid, lactic acid, glycolic acid, etc., with formic acid, acetic acid, and lactic acid being particularly preferred, and acetic acid being particularly preferred.

[0064] The amount of the co-catalyst used is not particularly limited, but from the viewpoints of reactivity, selectivity, and cost, it is preferred to use 1×10 co-catalyst per 1 mole of the organosilicon compound represented by general formula (II). -5 ~1 x 10 -1 mol is preferred, and 1×10 -4 ~5 x 10 -1 A molar range is more preferable. The reaction proceeds without a solvent, but a solvent can also be used. Examples of the solvent that can be used include hydrocarbon solvents such as pentane, hexane, cyclohexane, heptane, isooctane, benzene, toluene, and xylene; ether solvents such as diethyl ether, tetrahydrofuran, and dioxane; ester solvents such as ethyl acetate and butyl acetate; aprotic polar solvents such as N,N-dimethylformamide; and chlorinated hydrocarbon solvents such as dichloromethane and chloroform. These solvents can be used alone or in combination of two or more.

[0065] The reaction temperature is not particularly limited, and the reaction can be carried out at room temperature (23°C ± 10°C) or under heating. In order to obtain an appropriate reaction rate, the reaction is preferably carried out under heating, and the reaction temperature is preferably 35 to 200°C, more preferably 40 to 110°C, and even more preferably 40 to 90°C. The reaction time is also not particularly limited, and is preferably 1 to 60 hours, more preferably 1 to 30 hours, and even more preferably 1 to 20 hours.

[0066] [Component (D)] The platinum group metal catalyst of component (D) is a catalyst for promoting the addition reaction of the curable organopolysiloxane composition of the present invention, and any of those known to those skilled in the art for promoting the so-called hydrosilylation reaction can be used. Examples of such platinum group metal catalysts include platinum-based, palladium-based, rhodium-based, and ruthenium-based catalysts, and among these, platinum-based catalysts are particularly preferred. Examples of such platinum catalysts include chloroplatinic acid, alcohol solutions or aldehyde solutions of chloroplatinic acid, complexes of chloroplatinic acid with various olefins or vinylsiloxanes, and complexes of platinum with various olefins or vinylsiloxanes.

[0067] The amount of component (D) may be any amount so long as it is an effective amount as a catalyst. For example, from an economical standpoint, while still obtaining a good cured coating, the amount is preferably 0.1 to 200 ppm (by mass) of platinum group metal relative to the total mass of components (A) and (B), more preferably 0.5 to 150 ppm, even more preferably 1 to 100 ppm, and particularly preferably 2 to 50 ppm. In the present invention, by incorporating component (E) or by using an organopolysiloxane represented by the above formula (3) as component (A), it is possible to further reduce the platinum content to 30 ppm or less.

[0068] [Component (E)] Component (E) is an organopolysiloxane having 0.1 to 20 (meth)acrylic group-containing groups bonded to silicon atoms per molecule, and is an organopolysiloxane represented by the following formula (5), and can be used alone or in combination of two or more types. (R 9 3SiO 1 / 2 ) p (R 9 2SiO 2 / 2 ) q (R 9 SiO 3 / 2 ) r (SiO 4 / 2 )s (5) (wherein, R 9 are each independently a group selected from an alkenyl group having 2 to 12 carbon atoms, a hydroxyl group, an unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond, and a (meth)acrylic group-containing group; R 9Among these, 0.1 to 20 are (meth)acrylic group-containing groups, and p to s are positive numbers that satisfy 2≦p≦202, 5≦q≦1,000, 0 or 0<r≦100, and 0 or 0<s≦100, with the proviso that 0≦r+s≦100.

[0069] Component (E) has 0.1 to 20 silicon-bonded (meth)acrylic group-containing groups per molecule. Using 0.1 or more groups can further enhance the reactivity of the addition reaction. Furthermore, if the number exceeds 20, compatibility with components (A) and (B) may decrease, resulting in cloudiness. More specifically, the content of silicon-bonded (meth)acrylic group-containing groups is preferably 0.0001 to 0.6 mol / 100 g, more preferably 0.005 to 0.4 mol / 100 g, and even more preferably 0.01 to 0.2 mol / 100 g. By ensuring that the content of silicon-bonded (meth)acrylic group-containing groups is equal to or greater than the above-mentioned lower limit, the reactivity of the addition reaction can be further enhanced, and sufficient curability can be obtained even when the catalyst amount is reduced. Furthermore, if the content of silicon-bonded (meth)acrylic group-containing groups exceeds the above-mentioned upper limit, compatibility with components (A) and (B) may decrease, resulting in cloudiness.

[0070] In the above formula (5), examples of the (meth)acrylic group-containing group include the (meth)acrylic group-containing groups described in the organopolysiloxane represented by formula (3). As the (meth)acrylic group-containing group, a group represented by CH=CHCOOCH- is preferred.

[0071] Component (E) preferably contains at least 0.1 silicon-bonded alkenyl groups per molecule. More specifically, the content of silicon-bonded alkenyl groups is preferably 0.0001 to 0.15 mol / 100 g, more preferably 0.001 to 0.13 mol / 100 g, and even more preferably 0.005 to 0.1 mol / 100 g. By ensuring that the content of silicon-bonded alkenyl groups is equal to or greater than the above-mentioned lower limit, curability is further improved. Furthermore, by ensuring that the content of silicon-bonded alkenyl groups is equal to or less than the above-mentioned upper limit, an appropriate release force can be obtained.

[0072] In the above formula (5), examples of the alkenyl group and the unsubstituted or substituted monovalent hydrocarbon group that does not have an aliphatic unsaturated bond include those exemplified in the above formula (2), including suitable ones. Among these, in order to increase the curability and reduce the release force, it is preferable that all R 9 Preferably, 80 mol % or more of the groups are methyl groups.

[0073] The viscosity of component (E) at 25°C is preferably 10,000 mPa s or less, more preferably 5 to 5,000 mPa s, and even more preferably 10 to 1,000 mPa s. If the viscosity of component (E) exceeds the upper limit indicated above, compatibility with components (A) and (B) may decrease, resulting in the product becoming cloudy.

[0074] p to s are positive numbers that satisfy the following conditions: 2≦p≦202, 5≦q≦1,000, 0 or 0<r≦100 (0≦r≦100), and 0 or 0<s≦100 (0≦s≦100). p is preferably 2 to 102, q is preferably 10 to 500, r and s are preferably each independently 0 to 50, and r+s is preferably 0≦r+s≦50.

[0075] Examples of organopolysiloxanes of component (E) include compounds represented by the following formula: (R 9 3SiO 1 / 2 ) 2 (R 9 2SiO 2 / 2 ) q (R 9 3SiO 1 / 2 ) p (R 9 2SiO 2 / 2 ) q (R 9 SiO 3 / 2 ) r (R 9 3SiO 1 / 2 ) p (R 9 2SiO 2 / 2 ) q (SiO 4 / 2 ) s (R 9 3SiO 1 / 2 ) p (R 9 2SiO 2 / 2 ) q (R 9 SiO3 / 2 ) r (SiO 4 / 2 ) s In each of the above formulas, R 9 , p to s are as described above.

[0076] More specific examples include, but are not limited to, compounds represented by the following formula: (ViMeSiO 1 / 2 )2(Me2SiO 2 / 2 ) β1 (AMeSiO 2 / 2 ) β2 (0≦β1<1,000, 0.1≦β2≦20, 5≦β1+β2≦1,000) (Me3SiO 1 / 2 )2(Me2SiO) β3 (AMeSiO) β4 (0≦β3<1,000, 0.1≦β4≦20, 5≦β3+β4≦1,000) (ViMe2SiO 1 / 2 ) β5 (MeSiO 1 / 2 ) β6 (MeSiO 2 / 2 ) β7 (AMeSiO β8 (0.1≦β5<2, 0<β6≦1.9, β5+β6=2, 0≦β7<1,000, 0.1≦β8≦20, 5≦β7+β8≦1,000) (ViMe2SiO 1 / 2 )2(Me2SiO 2 / 2 ) β9 (ViMeSiO 2 / 2 ) β10 (AMeSiO 2 / 2 ) β11 (0≦β9<1,000, 0<β10<1,000, 0.1≦β11≦20, 5≦β9+β10+β11≦1,000) (ViMe2SiO 1 / 2 ) β12 (MeSiO 2 / 2 ) β13 (AMeSiO 2 / 2 ) β14 (MeSiO 3 / 2 ) β15(3≦β12≦102, 0≦β13<1,000, 0.1≦β14≦20, 5≦β13+β14≦1,000, 1≦β15≦100) (ViMe2SiO 1 / 2 ) β16 (MeSiO 2 / 2 ) β17 (AMeSiO 2 / 2 ) β18 (MeSiO 3 / 2 ) β19 (SiO 4 / 2 ) β20 (4≦β16≦202, 0≦β17<1,000, 0.1≦β18≦20, 5≦β17+β18≦1,000, 0≦β19≦100, 1≦β20≦100, 1≦β19+β20≦100) In each of the above formulas, Me, Vi, and A respectively represent a methyl group, a vinyl group, and CA: a group represented by CH2=CHCOOC3H6-.

[0077] When component (E) is incorporated, the amount is preferably 0.01 to 20 parts by mass, more preferably 0.05 to 15 parts by mass, and even more preferably 0.1 to 10 parts by mass, per 100 parts by mass of component (A). By adjusting the amount of component (E) to be equal to or greater than the above-mentioned lower limit, the reactivity of the addition reaction can be further increased, while by adjusting the amount to be equal to or less than the above-mentioned upper limit, more appropriate adhesion can be obtained. When component (E) contains silicon-bonded alkenyl groups, the ratio of the number of SiH groups in component (B) to the total number of alkenyl groups in components (A) and (E) is preferably 0.5 to 10, more preferably 0.8 to 8.0, and more preferably 1.0 to 5.0.

[0078] [Other Components] In addition to the above components (A) to (E), other optional components can be blended into the curable organopolysiloxane composition of the present invention, provided that the effects of the present invention are not impaired. The other components may be any of those typically used in addition reaction-curable organopolysiloxane compositions, and known components can be added in the usual amounts. Examples include the following components. Each of these other components may be used alone, or two or more may be used in combination.

[0079] [Component (F)] (F) Addition Reaction Inhibitor The curable organopolysiloxane composition of the present invention can further contain (F) an addition reaction inhibitor for the platinum group metal catalyst in order to ensure pot life. The addition reaction inhibitor is not particularly limited as long as it is a compound that has a cure-inhibiting effect on the platinum group metal catalyst of component (D), and conventionally known addition reaction inhibitors can be used. Examples include various organic nitrogen compounds, organic phosphorus compounds, acetylene compounds, and oxime compounds. More specifically, examples of the compound include acetylenic alcohols such as 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-pentyn-3-ol, 2-phenyl-3-butyn-2-ol, and 1-ethynylcyclohexanol; acetylenic compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-3-hexen-1-yne; reaction products of these acetylenic compounds with alkoxysilanes, siloxanes, or hydrogensilanes; vinylsiloxanes such as tetramethylvinylsiloxane cyclics; organic nitrogen compounds such as benzotriazole; and other organic phosphorus compounds; and oxime compounds.

[0080] When component (F) is added, it should be in an amount that provides a good pot life. Generally, it is preferably 0.01 to 10 parts by mass, and more preferably 0.05 to 5 parts by mass, per 100 parts by mass of the total of (A).

[0081] [Component (G)] The curable organopolysiloxane composition of the present invention can be blended with (G) an organic solvent. The curable organopolysiloxane composition of the present invention can be a solvent-free composition obtained by blending the above components (A) to (D) or (A) to (E) in predetermined amounts, but it can also be used as a solvent-based composition diluted with an organic solvent, if necessary. Diluting the composition with an organic solvent offers practical advantages such as improved adhesion, improved coating workability, and improved coating film condition, including coating film thickness and surface finish.

[0082] Examples of the organic solvent (G) include aromatic hydrocarbon compounds such as toluene and xylene, aliphatic hydrocarbon compounds such as hexane, heptane, and isoparaffin, ketone compounds such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, ester compounds such as ethyl acetate and butyl acetate, and ether compounds such as diisopropyl ether and 1,4-dioxane, but any compound that can dissolve the above components (A) to (F) is acceptable. These can be used alone or in appropriate combinations of two or more.

[0083] The amount of component (G) may be 0 parts by mass, and if the danger or reduced safety caused by organic solvents is undesirable, it is possible to omit component (G) and produce a solventless organopolysiloxane composition for producing release sheets. When component (G) is included, the amount is preferably 100 to 20,000 parts by mass, and more preferably 200 to 10,000 parts by mass, per 100 parts by mass of component (A). By incorporating component (G) in an amount of 100 parts by mass or more, the benefits of dilution are more readily obtained. Adding more than 20,000 parts by mass does not significantly improve the effects of dilution.

[0084] Furthermore, known antioxidants, light release additives, heavy release additives, pigments, stabilizers, antistatic agents, antifoaming agents, adhesion improvers, thickeners, and inorganic fillers such as silica can be blended as needed, provided that the effects of the present invention are not impaired. When these are blended, the amount is preferably in the range of 0.01 to 200 parts by mass per 100 parts by mass of component (A).

[0085] [Method for Producing Curable Organopolysiloxane Composition] There are no particular limitations on the method for producing the curable organopolysiloxane composition of the present invention, but from the perspective of pot life, a method in which (A), (B), (C), and, if necessary, components (E), (F), and (G), as well as other components, are pre-mixed to homogeneity, and then component (D) is added immediately before use is preferred.

[0086] [Curable Organopolysiloxane Composition] The viscosity at 25°C of the curable organopolysiloxane composition of the present invention is preferably 0.1 to 1,000 mPa·s, more preferably 1 to 800 mPa·s, and even more preferably 5 to 600 mPa·s, from the viewpoint of coatability onto a substrate.

[0087] There are no particular restrictions on the appearance of the curable organopolysiloxane composition, and it can be selected from opaque, transparent, semi-transparent, slightly opaque, etc. depending on the application.

[0088] The residual adhesion rate of the cured product of the curable organopolysiloxane composition is not particularly limited and can be appropriately selected depending on the purpose. For example, in the method of the Examples described below, it can be set to 50 to 120%, preferably 70 to 110%, and more preferably 90 to 100%.

[0089] [Release Sheet] The present invention provides a release sheet comprising a substrate and a release agent layer provided on at least one surface of the substrate, wherein the release agent layer is formed from a cured product obtained by curing the curable organopolysiloxane composition described above.

[0090] The substrate is preferably a sheet-like substrate, and may have one or both surfaces. A cured coating can be formed by applying the curable organopolysiloxane composition to one or both surfaces of the substrate and heating.

[0091] The coating method and heat curing conditions are not particularly limited and may be selected as appropriate. For example, the curable organopolysiloxane composition may be applied as is to one or both sides of a sheet-like substrate such as paper or film in an amount of 0.01 to 100 g / m using a coating method such as coating with a comma coater, lip coater, roll coater, die coater, knife coater, blade coater, rod coater, kiss coater, gravure coater, or wire bar coater, or by screen coating, dip coating, or cast coating. 2 After application, a cured coating can be formed on the substrate by heating for 1 to 120 seconds at 50 to 200° C. When forming release layers on both sides of the substrate, it is preferable to perform the cured coating formation operation on each side of the substrate at a time.

[0092] In addition to substrates made of paper, the present invention also includes substrates made of various known films. Examples of substrates include polyethylene-laminated paper, glassine paper, high-quality paper, various coated papers such as supercalendered kraft paper and clay-coated kraft paper, synthetic paper such as Yupo, polyethylene film, polypropylene films such as CPP and OPP, polyester films such as polyethylene terephthalate film, polyamide film, polyimide film, polylactic acid film, polyphenol film, polycarbonate film, etc. It is also possible to use casting paper used in the manufacture of artificial leather, ceramic sheets, double-sided separators, etc. To improve the adhesion between these substrates and the release layer, the substrate surface may be corona-treated, etched, primer-treated, or plasma-treated. Since the present invention provides a cured coating with high adhesion to supercalendered kraft paper and clay-coated kraft paper, it can also be used for supercalendered kraft paper and clay-coated kraft paper.

[0093] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following examples, unless otherwise specified, "%" in the composition indicates mass % and ratio indicates mass ratio. All viscosities are values ​​measured at 25°C using a rotational viscometer, and the vinyl value and acrylic value are 1 These are values ​​measured using H-NMR. Hereinafter, Me, n-Bu, Ph, Vi, and A represent a methyl group, a normal butyl group, a phenyl group, a vinyl group, and a group represented by CH2=CHCOOC3H6-, respectively.

[0094] The components used in the examples and comparative examples are as follows. In the following, the vinyl value refers to the number of moles of vinyl groups per 100 g of each component, the acrylic value refers to the number of moles of groups represented by CH═CHCOOC₃H₆- per 100 g of each component, and the SiH group content refers to the number of moles of SiH groups per 100 g of each component. The bonding order of the siloxane units shown in parentheses is not limited to the order shown below.

[0095] In the present invention, the number average molecular weight is a value obtained by GPC (gel permeation chromatography) analysis using polystyrene as a standard substance under the following conditions. [Measurement conditions] Developing solvent: toluene Flow rate: 0.35 mL / min Detector: differential refractive index detector (RI) Columns: TSKgel Guard column Super HZ-L (4.6 mm I.D. × 2 cm × 1) TSKgel Super HZ4000 (4.6 mm I.D. × 15 cm × 1) TSKgel Super HZ3000 (4.6 mm I.D. × 15 cm × 1) TSKgel Super HZ2000 (4.6 mm I.D. × 15 cm × 2) (all manufactured by Tosoh Corporation) Column temperature: 40°C Sample injection volume: 10 μL (toluene solution with a concentration of 0.5% by mass)

[0096] Synthesis Example 1 Synthesis of Silane-Modified Polybutadiene Compound 1 A 1 L separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer was charged with Ricon 130 (manufactured by CRAY VALLEY, Inc.; in the above formula (I), a = 33, b = 13, c = 0, d = 0, R 4 100 g of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (0.52 × 10 platinum atoms), 200 g of toluene, -4 mol), and 0.31 g (0.52 × 10 -2 63 g (0.52 mol) of trimethoxysilane was added dropwise to the mixture over 1 hour at an internal temperature of 75 to 85°C, followed by stirring at 80°C for 1 hour. After stirring was completed, the mixture was concentrated under reduced pressure and filtered to obtain a brown, transparent liquid with a number average molecular weight of 6,500. 1 The average structure determined from the H-NMR spectrum is: in the above general formula (1), a = 33, b = 0, c = 13, d = 0, R 1 = methyl group, R 4 The compound was a silane-modified polybutadiene compound represented by the formula: ##STR1## where m=3.

[0097] Synthesis Example 2 Synthesis of Silane-Modified Polybutadiene Compound 2 Into a 1 L separable flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, 100 g of Ricon 130, 200 g of toluene, and a toluene solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (0.24 × 10 as platinum atoms) were added. -4 mol), and 0.14 g (0.24 × 10 -2 29 g (0.24 mol) of trimethoxysilane was added dropwise to the mixture over 1 hour at an internal temperature of 75-85°C, followed by stirring at 80°C for 1 hour. After stirring was completed, the mixture was concentrated under reduced pressure and filtered to obtain a brown, transparent liquid with a number average molecular weight of 5,200. The molecular weight and 1 The average structure determined from the H-NMR spectrum was: a = 33, b = 7, c = 6, d = 0, R 1 = methyl group, R 4 The compound was a silane-modified polybutadiene compound represented by the formula: ##STR1## where m=3.

[0098] Synthesis Example 3 Synthesis of Silane-Modified Polybutadiene Compound 3 Into a 1 L separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, 100 g of Ricon 130, 200 g of toluene, and a toluene solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (0.12 × 10 as platinum atoms) were added. -4 mol), and 0.07 g (0.12 × 10 -2 14 g (0.12 mol) of trimethoxysilane was added dropwise to the mixture over 1 hour at an internal temperature of 75-85°C, followed by stirring at 80°C for 1 hour. After stirring was completed, the mixture was concentrated under reduced pressure and filtered to obtain a brown, transparent liquid with a number average molecular weight of 4,900. The molecular weight and 1 The average structure determined from the H-NMR spectrum was: a = 33, b = 10, c = 3, d = 0, R 1 = methyl group, R 4 The compound was a silane-modified polybutadiene compound represented by the formula: ##STR1## where m=3.

[0099] Synthesis Example 4 Synthesis of Silane-Modified Polybutadiene Compound 4 Into a 1 L separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, 100 g of Ricon 130, 200 g of toluene, and a toluene solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (0.08 × 10 as platinum atoms) were added. -4 mol), and 0.05 g (0.08 × 10 -2 9.7 g (0.08 mol) of trimethoxysilane was added dropwise to the mixture over 1 hour at an internal temperature of 75 to 85°C, and then the mixture was stirred at 80°C for 1 hour. After stirring was completed, the mixture was concentrated under reduced pressure to obtain a brown, transparent liquid with a number average molecular weight of 4,900. 1 The average structure determined from the H-NMR spectrum is: a = 33, b = 11, c = 2, d = 0, R 1 = methyl group, R 4 The compound was a silane-modified polybutadiene compound represented by the formula: ##STR1## where m=3.

[0100] Synthesis Example 5 Synthesis of Silane-Modified Polybutadiene Compound 5 A 1 L separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer was charged with a partially epoxidized copolymer of Ricon 130 (R in the above formula (1)). 3 is composed of the above formula (1-1), a = 33, b = 11, c = 0, d = 2, R 4 ═H), 100 g of a toluene solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (0.20 × 10 platinum atoms) -4 24 g (0.20 mol) of trimethoxysilane was added dropwise to the mixture over 1 hour at an internal temperature of 75-85°C. The mixture was then stirred at 80°C for 3 hours. After stirring, the mixture was concentrated under reduced pressure and filtered to obtain a pale yellow, transparent liquid with a number average molecular weight of 5,100. The molecular weight and 1 The average structure determined from the H-NMR spectrum was: a = 33, b = 6, c = 5, d = 2, R 1 = methyl group, R 4 The compound was a silane-modified polybutadiene compound represented by the formula: ##STR1## where m=3.

[0101] Synthesis Example 6 Synthesis of Silane-Modified Polybutadiene Compound 6 Into a 1 L separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, 100 g of Ricon 130, 31 g (0.04 mol) of an organohydrogenpolysiloxane represented by the following formula (6), 200 g of toluene, and a toluene solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (0.1 × 10 as platinum atoms) -5 mol) was added and stirred at 100°C for 8 hours. After the stirring was completed, the molecular weight and 1 The average structure determined from the H-NMR spectrum is: a = 33, b = 12, c = 0, d = 1, R 3 = a group represented by the following formula (7), R 4 Next, a toluene solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (0.48 × 10 platinum atoms) was prepared. -4 mol), and 0.29 g (0.48 × 10 -2 58 g (0.48 mol) of trimethoxysilane was added dropwise over 1 hour at an internal temperature of 75 to 85°C, and the mixture was stirred at 80°C for 1 hour. After stirring was completed, the mixture was concentrated under reduced pressure and filtered to obtain a pale yellow, transparent liquid with a number average molecular weight of 7,500. 1 The average structure determined from the H-NMR spectrum is: a = 33, b = 0, c = 12, d = 1, R 1 = methyl group, R 3 = a group represented by the following formula (7), R 4 The compound was a silane-modified polybutadiene compound represented by the formula: ##STR1## where m=3. (The asterisk * indicates a bond to the —CH— of the main chain.)

[0102] Synthesis Example 7 Synthesis of Silane-Modified Polybutadiene Compound 7 A 1 L separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer was charged with B-1000 (manufactured by Nippon Soda Co., Ltd., where a=2, b=18, c=0, d=0, R 4 100 g of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (1.6 × 10 platinum atoms), 200 g of toluene, and a toluene solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (1.6 × 10 platinum atoms).-4 mol), and 1.3 g (1.6 × 10 mol) of ammonium bicarbonate -2 263 g (1.6 mol) of triethoxysilane was added dropwise to the mixture over 2 hours at an internal temperature of 75-85°C, followed by stirring at 80°C for 1 hour. After stirring was completed, the mixture was concentrated under reduced pressure and filtered to obtain a brown, transparent liquid with a number average molecular weight of 6,400. 1 The average structure determined from the H-NMR spectrum is: in the above formula (1), a = 2, b = 0, c = 18, d = 0, R 1 = ethyl group, R 4 The compound was a silane-modified polybutadiene compound represented by the formula: ##STR1## where m=3.

[0103] Synthesis Example 8 Synthesis of Silane-Modified Polybutadiene Compound 8 Into a 1 L separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, 100 g of B-1000, 200 g of toluene, and a toluene solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (0.8 × 10 as platinum atoms) were added. -4 mol), and 0.63 g (0.8 × 10 mol) of ammonium bicarbonate -2 98 g (0.8 mol) of trimethoxysilane was added dropwise to the mixture over 1 hour at an internal temperature of 75 to 85°C, and then the mixture was stirred at 80°C for 1 hour. After stirring was completed, the mixture was concentrated under reduced pressure and filtered to obtain a brown, transparent liquid with a number average molecular weight of 3,500. 1 The average structure determined from the H-NMR spectrum is: a = 2, b = 9, c = 9, d = 0, R 1 = methyl group, R 4 The compound was a silane-modified polybutadiene compound represented by the formula: ##STR1## where m=3.

[0104] Component (A) (A-1-1) Methylvinylpolysiloxane (ViMeSiO) having both molecular chain terminals blocked with dimethylvinylsiloxy groups, a vinyl value of 0.018 mol / 100 g, and a viscosity of 380 mPa s 1 / 2 )2(Me2SiO 2 / 2 ) 150(A-1-2) An acrylic group-containing methylvinylpolysiloxane whose molecular chain is terminally blocked with dimethylvinylsiloxy groups and which has acrylic group-containing groups in its side chains, has a vinyl value of 0.018 mol / 100 g, an acrylic group content of 0.0009 mol / 100 g, and a viscosity of 420 mPa s: (ViMeSiO 1 / 2 )2(Me2SiO 2 / 2 ) 150 (AMeSiO 2 / 2 ) 0.1 (A-1-3) (ViMe2SiO 1 / 2 an organopolysiloxane having a viscosity of 15 Pa s at 25°C in a 30% by mass toluene solution and a vinyl group content of 0.020 mol / 100 g, the viscosity of which is 15 Pa s at 25°C in a 30% by mass toluene solution, and a vinyl group content of 0.020 mol / 100 g in a 30% by mass toluene solution, the viscosity of which is 15 Pa s at 25°C in a 30% by mass toluene solution, and a vinyl group content of 0.025 mol / 100 g in a 30% by mass toluene solution, the viscosity of which is 15 Pa s at 25°C in a 30% by mass toluene solution, and a vinyl group content of 0.020 mol / 100 g in a 30% by mass toluene solution, the vinyl group content of which is 0.025 mol / 100 g in a 30% by mass toluene solution, and a vinyl group content of 0.025 mol / 100 g in a 30% by mass toluene solution, the vinyl group content of which is ...

[0105] Component (B) (B-1) Methylhydrogenpolysiloxane (MeSiO) having both molecular chain terminals blocked with trimethylsiloxy groups, a SiH group content of 1.6 mol / 100 g, and a viscosity of 20 mPa s. 1 / 2 )2(MeHSiO 2 / 2 ) 40 (B-2) Methylhydrogenpolysiloxane (MeSiO) having both molecular chain terminals blocked with trimethylsiloxy groups, a SiH group content of 1.0 mol / 100 g, and a viscosity of 50 mPa s. 1 / 2 )2(MeHSiO 2 / 2 ) 45 (MeSiO 2 / 2 ) 20 (B-3) Methylhydrogenpolysiloxane (MeSiO) having both molecular chain terminals blocked with trimethylsiloxy groups, a SiH group content of 1.0 mol / 100 g, and a viscosity of 140 mPa s. 1 / 2 )2(MeHSiO 2 / 2 ) 80 (MeSiO 2 / 2 ) 40

[0106] Component (C) (C-1) Silane-modified polybutadiene compound 1 of Synthesis Example 1 (C-2) Silane-modified polybutadiene compound 2 of Synthesis Example 2 (C-3) Silane-modified polybutadiene compound 3 of Synthesis Example 3 (C-4) Silane-modified polybutadiene compound 4 of Synthesis Example 4 (C-5) Ricon 130 (manufactured by CRAY VALLEY Corporation), number average molecular weight 4,800 (C-6) Silane-modified polybutadiene compound 5 of Synthesis Example 5 (C-7) Silane-modified polybutadiene compound 6 of Synthesis Example 6 (C-8) Silane-modified polybutadiene compound 7 of Synthesis Example 7 (C-9) Silane-modified polybutadiene compound 8 of Synthesis Example 8 The structures of (C-1) to (C-9) are summarized in Table 1 below.

[0107]

[0108] Component (D) Platinum catalyst D used in the examples and comparative examples was prepared by diluting the reaction product of hexachloroplatinic acid and 1,3-divinyltetramethyldisiloxane with the above-mentioned methylvinylpolysiloxane (A-1-1) so that the platinum content was 0.50 mass%.

[0109] Component (E) (E-1) An acrylic group-containing methylvinylpolysiloxane whose molecular chain is terminally blocked with dimethylvinylsiloxy groups and which has acrylic group-containing groups in its side chains, has a vinyl value of 0.016 mol / 100 g, an acrylic group content of 0.077 mol / 100 g, and a viscosity of 450 mPa s: (ViMeSiO 1 / 2 )2(Me2SiO 2 / 2 ) 150 (AMeSiO 2 / 2 ) 10 (E-2) An acrylic group-containing methylpolysiloxane in which both molecular chain terminals are blocked with trimethylsiloxy groups and which has acrylic group-containing groups in its side chains, the content of the acrylic group-containing groups being 0.21 mol / 100 g, and the viscosity being 50 mPa s: (MeSiO 1 / 2 )2(Me2SiO 2 / 2 ) 40 (AMeSiO 2 / 2 ) 10

[0110] Component (F) (F) 1-ethynyl-1-cyclohexanol

[0111] Component (G) (G) Mixed solvent of toluene and hexane in a mass ratio of 1:1

[0112] Comparative Example Components (Comparative Products) (c-1) Phenyl-containing organohydrogenpolysiloxane represented by the following formula: (c-2) Epoxy group-containing organohydrogenpolysiloxane represented by the following formula: (c-3) Epoxy-, vinyl-, and methoxy-containing organopolysiloxanes represented by the following formula: (c-4) Epoxy group-containing organopolysiloxane represented by the following formula: (c-5) Epoxy group- and methoxy group-containing organopolysiloxane represented by the following formula:

[0113] Examples 1 to 9, Comparative Examples 1 to 6 (Solventless, Normal Platinum Amount) Components (A), (B), (F), and (C) or the components for comparative examples were placed in a flask according to the blending ratios shown in Tables 2, 3, and 5 below, and stirred until homogenous. To this mixture, component (D) was added so that the platinum content was 50 ppm relative to the total mass of components (A) and (B), and the mixture was stirred to obtain an organopolysiloxane composition for coating. The ratio of the number of SiH groups in component (B) to the number of alkenyl groups in component (A) (H / Vi) and the appearance (transparency) of the composition are shown in Tables 2, 3, and 5. Coated products were prepared using these compositions according to the methods described below and evaluated.

[0114] Examples 10-17, Comparative Examples 7-12 (Solventless, Low Platinum Amount) Components (A), (B), (E), (F), and (C) or the components for comparative examples were placed in a flask according to the blending ratios shown in Tables 3, 4, and 6 below, and stirred until homogenous. To this mixture, component (D) was added so that the platinum content was 25 ppm relative to the total mass of components (A) and (B), and the mixture was stirred to obtain an organopolysiloxane composition for coating. The ratio of the number of SiH groups in component (B) to the number of alkenyl groups in component (A) (H / Vi) and the appearance (transparency) of the composition are shown in Tables 3, 4, and 6. Using this composition, coated products were prepared and evaluated according to the method described below.

[0115] [Curing of Solventless Organopolysiloxane Composition] The solventless organopolysiloxane composition was applied to the metal roll of an RI tester (manufactured by IHI Machinery Systems Co., Ltd.), the metal roll was pressed against a rubber roll, and the two rolls were rotated for 45 seconds to uniformly stretch the composition. The polyethylene laminated paper onto which the composition had been transferred was then heated in a hot air dryer at 120°C for 20 seconds to form a sheet of polyethylene laminated paper with a thickness of 0.9 to 1.1 g / m. 2 A release paper having a cured coating of 1000 ppm was obtained.

[0116] Examples 18-19, Comparative Examples 13-14 (Solvent-Based) Components (A), (B), (F), and (C) or the comparative components were placed in a flask according to the blending ratios shown in Table 7 below, and 1,900 parts by mass of component (G) was added and stirred until uniform. Component (D) was added thereto in an amount equivalent to 150 ppm platinum relative to the total mass of components (A) and (B), and the mixture was stirred to obtain an organopolysiloxane composition for coating. The ratio of the number of SiH groups in component (B) to the number of alkenyl groups in component (A) (H / Vi) and the appearance (transparency) of the composition are shown in Table 7. Using this composition, coated products were prepared and evaluated according to the method described below.

[0117] [Curing of Solvent-Based Organopolysiloxane Composition] The solvent-based organopolysiloxane composition is applied to polyethylene-laminated paper using a bar coater, and heated in a hot air dryer at 120°C for 20 seconds to form a film having a thickness of 0.9 to 1.1 g / m. 2 A release paper having a cured coating of 1000 ppm was obtained.

[0118] [Peel Strength] The release paper obtained by the above curing method was aged at 25°C for 24 hours, and then a 25 mm wide acrylic adhesive tape TESA-7475 (TESA UK Ltd) was laminated to the cured film surface of this release paper (the side transferred from the rubber roll) and cut into a size of 25 mm x 23 cm. This was sandwiched between glass plates and cured at 70°C with a pressure of 20 g / cm. 2The specimens were aged for 24 hours under a load of 0.5g / cm2 for 10 minutes. After air cooling for about 30 minutes, the TESA-7475 tape samples were peeled off at an angle of 180° at a rate of 0.3 m / min using a tensile tester (Shimadzu Corporation, DSC-500 model), and the force required for peeling was measured. The results are shown in Tables 2 to 7.

[0119] [Rate of change in peel force (%)] Using the peel forces obtained by the above measurement method, the rate of change in peel force (%) was calculated according to the following method: Peel force of Examples 1 to 9 and Comparative Examples 2 to 6 / Peel force of Comparative Example 1 × 100 Peel force of Examples 10 to 17 and Comparative Examples 8 to 12 / Peel force of Comparative Example 7 × 100 Peel force of Examples 18 to 19 and Comparative Example 13 / Peel force of Comparative Example 13 × 100 Since Comparative Examples 1, 7, and 13 each correspond to compositions to which no adhesion improver was added, the rate of change in peel force when an adhesion improver was added can be calculated according to the above calculation. The results are shown in Tables 2 to 7.

[0120] [Residual Adhesion Rate] The adhesive side of the TESA-7475 tape peeled from the release layer in the above peel force measurement was attached to a stainless steel plate, and a load was applied by moving a 2 kg roller back and forth. After leaving it for 30 minutes, one end of the TESA-7475 tape was peeled off, and that end was pulled in a direction at an angle of 180 degrees to the stainless steel plate at a peel rate of 0.3 m / min. The force required for peeling was measured: peel force A (gf / 25 mm). In addition, unused TESA-7475 tape not attached to the release layer was attached to the stainless steel plate. Under the same conditions as above, the force required to peel the TESA-7475 tape from the stainless steel plate: peel force B (gf / 25 mm) was measured. The results are shown in Tables 2 to 7. The residual adhesion rate (%) was calculated using the formula: residual adhesion rate (%) = (A / B) × 100.

[0121] [Adhesion] In the same manner as above, a release layer was formed on polyethylene-laminated paper (referred to as "Polylami" in the table) to obtain release paper. Furthermore, by changing the substrate, release layers were formed on supercalendered kraft paper (referred to as "SCK" in the table), clay-coated kraft paper (referred to as "CCK" in the table), and glassine paper (referred to as "Glassine" in the table) to obtain release papers. The curing conditions for the supercalendered kraft paper, clay-coated kraft paper, and glassine paper were 150°C x 30 seconds, and the thickness was 1.0 to 1.2 g / m. 2 The resulting release papers were aged at 25°C for 24 hours and then stored under the conditions described below. After that, the release layer was rubbed with a finger 10 times and visually observed to see whether it had fallen off the substrate, and evaluated according to the following criteria. The results are shown in Tables 2 to 7.

[0122] [Evaluation criteria] Cured products of solventless organopolysiloxane compositions Polyethylene laminated paper A: No peeling even after 15 hours at 85°C and 85% RH B: No peeling observed after 10 hours at 85°C and 85% RH, but fell off after 15 hours at 85°C and 85% RH C: No peeling observed after 5 hours at 85°C and 85% RH, but fell off after 10 hours at 85°C and 85% RH D: Falling off after 5 hours at 85°C and 85% RH Supercalendered kraft paper, clay-coated kraft paper and glassine paper A: No peeling even after 48 hours at 85°C and 85% RH B: No peeling observed after 24 hours at 85°C and 85% RH, but fell off after 48 hours at 85°C and 85% RH C: No peeling observed after 24 hours at 25°C, but fell off after 24 hours at 85°C and 85% RH D: Falling off after 24 hours aging at 25°C Cured products of solvent-based organopolysiloxane compositions Polyethylene laminated paper, supercalendered kraft paper, clay-coated kraft paper, and glassine paper A: No falling off even after 96 hours at 85°C and 85% RH B: No falling off observed after 48 hours at 85°C and 85% RH, but falling off after 96 hours at 85°C and 85% RH C: No falling off observed after 24 hours aging at 25°C, but falling off after 48 hours at 85°C and 85% RH D: Falling off after 24 hours aging at 25°C In the present invention, for solventless organopolysiloxane compositions, adhesion of C or higher (A, B, C) is considered a passing grade, and for solvent-based organopolysiloxane compositions, adhesion of B or higher (A, B) is considered a passing grade.

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130] As shown in the above results, Comparative Examples 1, 7, and 13, which did not contain the adhesion promoter (C), and Comparative Examples 2 to 6, 8 to 12, and 14, which contained components other than component (C), showed improved adhesion to some substrates, but the effect was insufficient. Furthermore, Comparative Examples 2 to 4, 8 to 10, and 14, which contained an SiH-containing component, showed higher peel strengths than the no-additive cases. In contrast, Examples 1 to 19, which contained the adhesion promoter (C) of the present invention, showed excellent adhesion to a wide range of substrates and showed less change in peel strength than the no-additive cases. Although Examples 10 to 17 had low platinum compositions, the incorporation of an organopolysiloxane represented by formula (3) or component (E) as component (A) maintained high adhesion to various substrates even with a low platinum content. Furthermore, the Examples had high residual adhesion rates.

[0131] The curable organopolysiloxane composition of the present invention exhibits good adhesion to paper substrates such as supercalendered kraft paper and clay-coated kraft paper, and can form cured coatings with good release strength and residual adhesion. Therefore, the curable organopolysiloxane composition of the present invention can be suitably used as an organopolysiloxane composition for release sheets.

Claims

1. A curable organopolysiloxane composition comprising the following components (A) to (D): (A) 100 parts by mass of an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule, (B) an organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms (SiH groups) per molecule, in an amount such that the ratio of the number of SiH groups in component (B) to the number of alkenyl groups in component (A) is 0.5 to 10, and (C) a compound represented by the following general formula (1): [In the formula, R 1 , R 2 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and R 3 are represented by the following formula (1-1) or (1-2), respectively: (In the formula, R 5 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and n is a positive number from 1 to 100. An asterisk * indicates a bond to —CH— in the main chain. 4 are each independently a hydrogen atom or a group represented by -CH2CH2OH, a is a positive number satisfying 0 < a ≦ 120, b is 0 or a positive number satisfying 0 < b ≦ 100, c is 0 or a positive number satisfying 0 < c ≦ 100, d is 0 or a positive number satisfying 0 < d ≦ 20, and 0 < b + c ≦ 200, and m is an integer of 1 to 3, provided that the order of the respective repeating units is arbitrary.] A polybutadiene compound represented by the formula: 0.01 to 10 parts by mass per 100 parts by mass of component (A), (D) a platinum group metal catalyst: a catalytic amount 2. The curable organopolysiloxane composition according to claim 1, wherein the polybutadiene compound of component (C) has a number average molecular weight of 1,000 to 1,000,000.

3. The curable organopolysiloxane composition according to claim 1, wherein the polybutadiene compound of component (C) independently satisfies the following conditions (i), (ii), and (iii) for a, b, c, and d in general formula (1): 0.05≦c / (a+b+c+d)<1.0 (i) 0.1≦c / (b+c)≦1.0 (ii) 0.05≦(b+c) / (a+b+c+d)≦0.95 (iii).

4. The curable organopolysiloxane composition according to claim 1, wherein component (A) is an organopolysiloxane represented by the following formula (2): (R 6 3SiO 1 / 2 ) e (R 6 2SiO 2 / 2 ) f (R 6 SiO 3 / 2 ) g (SiO 4 / 2 ) h (2) (wherein, R 6 are each independently a group selected from an alkenyl group having 2 to 12 carbon atoms, a hydroxyl group, and an unsubstituted or substituted monovalent hydrocarbon group that does not have an aliphatic unsaturated bond, and R 6 at least two of the groups are alkenyl groups, e is 2 or more, f is 0 or 0<f, g is 0 or 0<g, and h is a positive number of 0 or 0<h, and e+f+g+h is selected so that the viscosity at 25°C is 1 mPa s or more and 70,000 mPa s or less when dissolved in 30% by mass toluene.

5. The curable organopolysiloxane composition according to claim 1, wherein component (A) is an organopolysiloxane represented by the following formula (3): (R 7 3SiO 1 / 2 ) v (R 7 2SiO 2 / 2 ) w (R 7 SiO 3 / 2 ) x (SiO 4 / 2 ) y (3) (wherein, R 7 are each independently a group selected from an alkenyl group having 2 to 12 carbon atoms, a hydroxyl group, an unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond, and a (meth)acrylic group-containing group; R 7 At least two of R are alkenyl groups; 7 of which 0.01 to 2.9 are (meth)acrylic group-containing groups, v is 2 or more, w is 8 or more, x is 0 or a positive number satisfying 0<x, y is a positive number satisfying 0 or 0<y, and v+w+x+y is selected so that the viscosity at 25°C is 1 mPa s or more and 70,000 mPa s or less when dissolved in 30% by mass toluene.

6. The curable organopolysiloxane composition according to claim 1, wherein component (B) is represented by the following average composition formula (4): 8 t H u SiO (4-t-u) / 2 (4) (wherein, R 8 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and containing no aliphatic unsaturated bonds, and t and u are positive numbers satisfying the conditions 0.7≦t≦2.1, 0.001≦u≦1.0, and 0.8≦t+u≦3.0, with the proviso that component (B) has at least two hydrogen atoms bonded to silicon atoms.

7. The curable organopolysiloxane composition according to claim 1, further comprising (E) 0.01 to 20 parts by mass per 100 parts by mass of component (A) of an organopolysiloxane represented by the following formula (5) and having 0.1 to 20 (meth)acrylic group-containing groups bonded to silicon atoms per molecule: (R 9 3SiO 1 / 2 ) p (R 9 2SiO 2 / 2 ) q (R 9 SiO 3 / 2 ) r (SiO 4 / 2 ) s (5) (wherein, R 9 are each independently a group selected from an alkenyl group having 2 to 12 carbon atoms, a hydroxyl group, an unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond, and a (meth)acrylic group-containing group; R 9 Among these, 0.1 to 20 are (meth)acrylic group-containing groups, and p to s are positive numbers that satisfy 2≦p≦202, 5≦q≦1,000, 0 or 0<r≦100, and 0 or 0<s≦100, with the proviso that 0≦r+s≦100.

8. A release sheet comprising a substrate and a release agent layer provided on at least one surface of the substrate, wherein the release agent layer is formed from a cured product obtained by curing the curable organopolysiloxane composition described in claim 1.

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