Organopolysiloxane composition for release sheet

Abstract

This organopolysiloxane composition for a release sheet contains the following components (A), (B), and (C), and can form a cured film having low dependency of peel strength on speed. (A) is 100 parts by mass of a multi-branched organopolysiloxane having an average of four or more alkenyl groups per molecule. (B) is an organohydrogen siloxane having an average of three or more silicon-bonded hydrogen atoms per molecule, wherein the ratio of the number of Si–H groups in component (B) to the total number of alkenyl groups in component (A) is 1-5. (C) is a platinum group metal-based catalyst in which the amount of a platinum group metal with respect to the total composition is 1-200 ppm in terms of mass.

Description

Organopolysiloxane composition for release sheets

[0001] The present invention relates to a silicone composition for release sheets that exhibits minimal dependency of release force on release rate.

[0002] Conventionally, to prevent adhesion or sticking between sheet-like substrates such as paper or plastic and adhesive materials, a cured coating of an organopolysiloxane composition has been formed on the substrate surface to impart release properties. Methods for forming a cured organopolysiloxane coating on a substrate surface are well known, including the following: (1) A method in which a release coating is formed by addition reaction of an alkenyl-containing organopolysiloxane with an organohydrogenpolysiloxane using a platinum group metal compound as a catalyst; (2) A method in which a release coating is formed by condensation reaction of an organopolysiloxane having functional groups such as hydroxyl groups or alkoxy groups using an organometallic salt as a catalyst; and (3) A method in which a release coating is formed by radical polymerization of an acrylic-containing organopolysiloxane with a photoinitiator using ultraviolet light or electron beams.

[0003] Among the above methods (1), (2), and (3), the method (1) for forming a release coating by addition reaction using a platinum catalyst is widely used because it has excellent curing properties and can meet various release property requirements from low to high release speeds.

[0004] In recent years, the speed of release agent coating and converting processes has been rapidly increasing in order to improve the productivity of label products. The peel speed dependency of a release agent can be expressed by a graph with peel speed on the horizontal axis and peel force on the vertical axis, and generally the graph shows an upward slope, with the peel force increasing as the peel speed increases.

[0005] In the machine labeling process, where labels are attached by machine, if the peel force cannot be controlled within a certain range, the label will not be attached properly, leading to reduced productivity. If the peel force is below a certain range, the label will warp when attached to an object and will not be able to be attached properly. On the other hand, if the peel force exceeds a certain range, the label will not peel off from the release paper or film as desired, causing the problem of not being able to attach it to the object. Furthermore, in the casting process during converting, if the peel force is too strong, the matrix will break and will not be able to be properly recovered, causing the problem of reduced productivity.

[0006] Therefore, there is a demand for a method for forming a release coating in which the difference in release force between manual peeling (0.3 m / min) and mechanical peeling (60 m / min to 300 m / min) is small, i.e., the release force has little dependency on the peeling speed.

[0007] Furthermore, regulations on low-molecular-weight siloxanes are becoming stricter, with D4 and D6 designated as monitored chemical substances in Japan. Furthermore, in Europe, D4, D5, and D6 are listed on the candidate list of Substances of Very High Concern (SVHCs), and restrictions will be put in place from 2020 on products containing 0.1% by mass or more of these compounds in personal care, cleaning, and detergent applications, requiring that the amounts of D4, D5, and D6 be less than 0.1% by mass each.

[0008] Patent No. 7364040

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an addition-curable organopolysiloxane composition for release sheets that is capable of forming a cured film with low speed dependency of release force.

[0010] As a result of extensive research into achieving the above-mentioned object, the present inventors discovered that by using (A) a hyperbranched organopolysiloxane having an average of four or more silicon-bonded alkenyl groups per molecule in an addition reaction-curable organopolysiloxane composition, it is possible to form a cured coating that exhibits easy release and low speed dependency of the release force in both low and high peel speeds, and this discovery led to the completion of the present invention.

[0011] Accordingly, the present invention provides the following inventions: 1. An organopolysiloxane composition for release sheets, comprising the following components (A), (B), and (C): (A) 100 parts by mass of a hyperbranched organopolysiloxane having an average of four or more alkenyl groups per molecule; (B) an organohydrogensiloxane having an average of three or more silicon-bonded hydrogen atoms per molecule: in an amount such that the ratio of the number of SiH groups in component (B) to the total number of alkenyl groups in component (A) is 1 to 5; and (C) a platinum group metal catalyst: in an amount calculated as platinum group metal by mass based on the entire composition. 2. The organopolysiloxane composition for release sheets according to 1, further comprising: (D) an addition reaction inhibitor: in an amount of 0.01 to 10 parts by mass based on 100 parts by mass of the total of components (A), (B), and (C). 3. 3. The organopolysiloxane composition for release sheets according to claim 2, wherein component (D) is a mixture containing an acetylene group-containing compound having a hydroxyl group and a silane having an acetylene group. 4. The organopolysiloxane composition for release sheets according to any one of claims 1 to 3, further containing (E) an organopolysiloxane having an average of 0.1 or more alkenyl groups and an average of 0.1 to 20 (meth)acrylic groups per molecule, wherein the mass ratio of (A) to (E) is (A):(E) is 50 to 99.9:50 to 0.1. 5. The organopolysiloxane composition for release sheets according to any one of claims 1 to 3, wherein component (A) is a hydroxyl group represented by the following formula (1): a M Vi b D c D Vi d T e T Vi f Q g (1) (Where M is RSiO 1 / 2 , M Vi is R2PSiO 1 / 2 , D is RSiO 2 / 2 , D Vi is RPSiO 2 / 2 , T is RSiO 3 / 2 , T Vi is PSiO 3 / 2 , Q is SiO 4 / 2 R is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and no aliphatic unsaturated bond. P is -(CH2) h5. The organopolysiloxane composition for release sheets according to any one of 1 to 4, wherein the organopolysiloxane composition is represented by the formula: -CH=CH2 (h is an integer of 0 to 6), a, b, d, and f are each independently 0 or a positive number, provided that b, d, and f are not all 0 at the same time, a+b≧4, 4≦b+d+f≦500, c is a positive number from 10 to 2,700, e is 0 or a positive number of 200 or less, and g is a positive number of 0 or 100 or less, provided that e, f, and g are not all 0 at the same time, and e+f+g≧2, and has an average of four or more alkenyl groups per molecule, and the alkenyl group content is 0.001 mol / 100g or more and less than 0.7 mol / 100g. 6. The organopolysiloxane composition for a release sheet according to any one of 1 to 5, wherein the component (A) is a hyperbranched organopolysiloxane having an average of 4 to 8 alkenyl groups per molecule. 2 / s or more 450mm 2 8. The organopolysiloxane composition for a release sheet according to any one of 1 to 6, wherein the component (B) is a hyperbranched organopolysiloxane having a molecular weight of less than 1 / s. r MH s D t D H u T v T H w Q x (3) (Where M is RSiO 1 / 2 , M H is R2HSiO 1 / 2 , D is RSiO 2 / 2 , D H is RHSiO 2 / 2 , T is RSiO 3 / 2 , T H is HSiO 3 / 2 , Q is SiO 4 / 2wherein R is independently an unsubstituted or substituted monovalent hydrocarbon group of 1 to 12 carbon atoms and does not contain an aliphatic unsaturated bond; r, s, t, and v are independently 0 or a positive number; u is 0 or a positive number of 200 or less; w is 0 or a positive number of 10 or less; x is 0 or a positive number of 10 or less, wherein s, u, and w are not simultaneously 0, and 3≦s+u+w≦200. 9. The organopolysiloxane composition for release sheets according to any one of 1 to 7, wherein the organopolysiloxane is an organohydrogenpolysiloxane represented by the formula (I). R is independently an unsubstituted or substituted monovalent hydrocarbon group of 1 to 12 carbon atoms and does not contain an aliphatic unsaturated bond; r, s, t, and v are independently 0 or a positive number; u is 0 or a positive number of 200 or less; w is 0 or a positive number of 10 or less; x is 0 or a positive number of 10 or less; s, u, and w are not simultaneously 0; and 3≦s+u+w≦200. 9. The organopolysiloxane composition for release sheets according to 1 or 4, wherein the total content of cyclooctamethyltetrasiloxane, cyclodecamethylpentasiloxane, and cyclododecamethylhexasiloxane is 1,000 ppm (mass) or less in component (A) or the sum of component (A) and component (E). 10. 10. The organopolysiloxane composition for release sheets according to any one of 1 to 8, wherein the release force when TESA-7475 tape is peeled from a release sheet that is a cured product of the organopolysiloxane for release sheets at a peel rate of 150 m / min in accordance with FINAT Test Method No. 4 is less than 2.5 times the release force when TESA-7475 tape is peeled from a release sheet that is a cured product of the organopolysiloxane for release sheets at a peel rate of 150 m / min in accordance with FINAT Test Method No. 4. 9. The organopolysiloxane composition for release sheets according to any one of 1 to 8, wherein the peel force when TESA-7475 tape is peeled at a peeling rate of 0.3 m / min according to 3 is more than 1.2 and less than 2.5.

[0012] The organopolysiloxane composition of the present invention can provide an organopolysiloxane composition for release sheets that is capable of forming a cured film with low speed dependency of the release force.

[0013] The present invention will be described in detail below. [Component (A)] Component (A) of the present invention is a hyperbranched organopolysiloxane having an average of four or more alkenyl groups per molecule, and can be used alone or in combination of two or more. The alkenyl groups are preferably bonded to silicon atoms. The average number of alkenyl groups is four or more, preferably 4 to 8, and more preferably 4 to 6. If the average number of alkenyl groups is less than four, the release force increases during high-speed peeling, and the speed dependency of the release force becomes high. Because the component is hyperbranched, the number of branches is two or more, preferably 2 to 6, and more preferably 2 to 4. If the average number of branches is less than two, the release force increases during high-speed peeling, and the speed dependency of the release force becomes high.

[0014] The component (A) is a compound represented by the following formula (1): a M Vi b D c D Vi d T e T Vi f Q g (1) (Where M is RSiO 1 / 2 , M Vi is R2PSiO 1 / 2 , D is RSiO 2 / 2 , D Vi is RPSiO 2 / 2 , T is RSiO 3 / 2 , T Vi is PSiO 3 / 2 , Q is SiO 4 / 2 R is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and no aliphatic unsaturated bond. P is -(CH2) h an alkenyl group represented by -CH=CH2 (h is an integer of 0 to 6); a, b, d, and f each independently represent 0 or a positive number, provided that b, d, and f are not all 0 at the same time, a+b≧4, 4≦b+d+f≦500, c is a positive number from 10 to 2,700, e is 0 or a positive number of 200 or less, and g is a positive number of 0 or 100 or less, provided that e, f, and g are not all 0 at the same time, and e+f+g≧2.

[0015] In formula (1), R independently represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and no aliphatic unsaturated bonds, preferably one having 1 to 10 carbon atoms, and more preferably one having 1 to 8 carbon atoms. Specific examples include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, and dodecyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl, naphthyl, and tolyl; aralkyl groups such as benzyl and phenethyl; and groups in which some of the hydrogen atoms bonded to the carbon atoms of these groups have been substituted with halogen atoms, epoxy groups, amino groups, polyether groups, cyano groups, hydroxyl groups, or the like. Among these, in order to reduce the curability and the peel strength of the resulting cured product, it is preferred that 80 mol % or more of the total number of R groups be methyl groups.

[0016] P is -(CH2) h It is an alkenyl group represented by -CH=CH2 (h is an integer of 0 to 6). Specific examples include vinyl, allyl, butenyl, propenyl, 5-hexenyl, octenyl, and decenyl groups, with vinyl being preferred. h is an integer of 0 to 6, preferably 0 to 3.

[0017] a, b, d, and f are each independently 0 or a positive number, b, d, and f are not all 0 at the same time, a + b ≧ 4, 4 ≦ b + d + f ≦ 500, c is a positive number from 10 to 2,700, e is 0 or a positive number of 200 or less, g is a positive number of 0 or 100 or less, e, f, and g are not all 0 at the same time, and e + f + g ≧ 2. It is preferable that e and g are not all 0 at the same time, and that e + g ≧ 2. a is preferably a positive number of 0 or 100 or less, b is preferably a positive number of 0 or 100 or less, d is preferably a positive number of 0 or 500 or less, and f is preferably a positive number of 0 or 100 or less. a + b ≧ 4, and a + b ≧ 5 are preferred. 4 ≦ b + d + f ≦ 500, and 4 ≦ b + d + f ≦ 200 are preferred. c is a positive number from 10 to 2,700, preferably from 30 to 2,000, and more preferably from 50 to 1,500. When c is 10 or more, the composition can be easily applied to the roll, splashing is prevented during roll rotation, and the amount that can be applied to the substrate can be easily adjusted. e is a positive number of 0 or 200 or less, preferably a positive number of 2 or 20 or less, and more preferably a positive number of 2 or 10 or less. g is a positive number of 0 or 100 or less, and preferably a positive number of 0 or 5 or less. Note that e and g are not simultaneously 0, and e + g ≧ 2, and preferably e + g ≧ 2 to 6, and more preferably e + g ≧ 2 to 4.

[0018] Specific examples of the component (A) include polysiloxanes having a terminal alkenyl group, polysiloxanes having a side chain alkenyl group, polysiloxanes having a terminal alkenyl group and a side chain alkenyl group, and polysiloxanes having a terminal alkenyl group and a side chain alkenyl group. Vi 4D c T2, M Vi 5D c T3, M Vi 6D c T4, M Vi 7D c T5, M Vi 8D c T6, M a D c D Vi d T e , M Vi b D c DVi d T e , M Vi 6D c Q2, M a D c D Vi d T Vi f , M Vi 5D c T1Q1 (M, M Vi , D, D Vi , T, T Vi , Q, a, b, c, d, e, f, and g are the same as above. The same applies below.) Further specific structural formulas include M Vi 4D 100 T2, M Vi 5D 180 T3, M Vi 6D 250 T4, M Vi 6D 230 T4, M Vi 7D 320 T5, M Vi 4D 95 D5T2, M Vi 5D 170 T3, M4D 120 D Vi 3T Vi 2 etc. can be mentioned.

[0019] The vinyl value of component (A) is preferably 0.001 to 0.7 mol / 100g, more preferably 0.005 to 0.5 mol / 100g, and even more preferably 0.02 to 0.1 mol / 100g. A vinyl value of 0.001 mol / 100g or more increases the number of reaction sites and improves curability, while a vinyl value of 0.7 mol / 100g or less can achieve a crosslink density more suitable for low-speed peel strength. The vinyl value of the present invention is a value calculated from the iodine value obtained by measurement using the Hanus method in accordance with JIS K 0070.

[0020] The weight average molecular weight of component (A) is preferably 800 to 200,000, more preferably 1,000 to 150,000, and even more preferably 1,500 to 100,000. If the weight average molecular weight of component (A) is 800 or more, a more sufficient coating amount can be achieved, and if it is 200,000 or less, the wettability is superior. In the present invention, the weight average molecular weight is a value measured by gel permeation chromatography (GPC) analysis (solvent: toluene) in terms of polystyrene (the same applies hereinafter).

[0021] The kinematic viscosity of component (A) at 25°C measured using an Ostwald viscometer was 7 mm 2 / s or more 3 million mm 2 / s or less is preferable, and 10 to 10,000 mm 2 / s is more preferable, and 100 to 450 mm 2 / s is more preferable, and 100 mm 2 / s or more 450mm 2 By setting the viscosity within the above range, the composition can be easily spread appropriately on the target, and the coating properties on the substrate can be further improved.

[0022] [Component (E)] In the present invention, an organopolysiloxane having an average of 0.1 or more alkenyl groups and an average of 0.1 to 20 (meth)acrylic groups per molecule may be used in combination with component (A). These may be used alone or in combination of two or more. The alkenyl groups are preferably silicon-bonded, and the number per molecule is preferably 0.1 to 10. The (meth)acrylic groups are preferably silicon-bonded, and the number per molecule is preferably 0.1 to 15, more preferably 0.5 to 15.0, and even more preferably 1 to 10.

[0023] Examples of the component (E) include organopolysiloxanes having a structure represented by the following formula (2): α i M j D α k D L T α m T n Q q (2) (wherein M is R3 SiO 1 / 2 ,D is R 2 SiO 2 / 2 , T is RSiO 3 / 2 , Q is SiO 4 / 2 , M α is AcRSiO 1 / 2 : M Ac or R2PSiO 1 / 2 : M Vi , D α is AcRSiO 2 / 2 :D Ac or RPSiO 2 / 2 :D Vi , T α is AcSiO 3 / 2 : T Ac or PSiO 3 / 2 : T Vi R is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and no aliphatic unsaturated bonds, and P is —(CH) h is an alkenyl group represented by -CH=CH2 (h is an integer of 0 to 6), and Ac is CH2=CR 3 COOR 4 (R 3 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and R 4 is a divalent hydrocarbon group having 1 to 6 carbon atoms, which may have a branched or cyclic structure, and may contain an epoxy group, an ester group, a urethane group, an ether group, an isocyanate group, or a hydroxyl group. i is a positive number from 0 to 4, j is 0 or a positive number from 0 to 7, i+j is a number from 2 to 7, k is a positive number from 0.1 to 20, L is a positive number from 3 to 300, m and n are both 0 or a positive number from 0 to 10, and q is 0 or a positive number from 0 to 4. However, these are appropriately selected so that one molecule contains an average of 0.1 or more alkenyl groups and an average of 0.1 to 20 (meth)acrylic groups.

[0024] i is a positive number from 0 to 4, j is 0 or a positive number from 0 to 7, and i + j is a number from 2 to 7. i is preferably 2 or 3, in which case j is preferably 0. k is a positive number from 0.1 to 20, preferably a positive number from 0.5 to 15, and more preferably a positive number from 1 to 12. When k is 0.1 or greater, good curing properties can be achieved even when the amount of platinum group catalyst (C) described below is reduced. From the viewpoint of compatibility with component (A), k is preferably 20 or less. L is a positive number from 3 to 300, preferably a positive number from 5 to 180, and more preferably a positive number from 10 to 160. m and n are both 0 or a positive number from 0 to 10, preferably 0 or a positive number from 0 to 6, and more preferably 0 or a positive number from 0 to 3. q is 0 or a positive number from 0 to 4, preferably 0 to 2. By setting q to 4 or less, it is possible to further prevent the viscosity from becoming too high and the peel force from becoming too large.

[0025] Specific examples of the organopolysiloxane compound (E) include M Vi 2D5D Ac 3. M Vi 2D 20 D Ac 5. M Vi 2D 20 D Ac 5. M Vi 2D 30 D Ac 7. M Vi 2D 90 D Ac 1. M Vi 2D 90 D Ac 9. M Vi 2D Vi 1D 230 D Ac 7. M Vi 2D 25 D Ac 7. M Vi 2D 65 D Ac 15 , M Vi 2D 265 D Ac 15 , M Vi 2D 61 D Ac 15 , M Vi 1M Ac 1D 10 DAc 3. M Vi 2D 110 D Ac 7. M Vi 3D 20 D Ac 5T1, M Vi 2D 150 D Ac 10 , M Vi 3D 110 D Ac 6T1, M Vi 2D 170 D Ac 22 , M Vi 2D 170 D Ac 20 Q1, M AC 2D 20 D Vi 1. M2D Vi 1D 30 D Ac 1st place etc.

[0026] The vinyl value of the component (E) is preferably from 0.001 to 0.3 mol / 100 g, and more preferably from 0.01 to 0.1 mol / 100 g.

[0027] The weight average molecular weight of the component (E) is preferably 3,000 or more and 100,000 or less, and more preferably 5,000 or more and 30,000 or less.

[0028] The kinematic viscosity of component (E) at 25°C measured using an Ostwald viscometer is 10 to 10,000 mm 2 / s is preferred, and 50 to 3,000 mm 2 By setting the viscosity within the above range, the entire composition has an appropriate kinematic viscosity, which makes it easy to spread appropriately on the target, and further improves the coatability onto the substrate.

[0029] When the component (E) is used, the mass ratio of (A) to (E), (A):(E), is preferably 50 to 99.9:50 to 0.1, more preferably (A):(E)=70:30 to 99.8:0.2, and even more preferably (A):(E)=80:20 to 99.5:0.5.

[0030] When component (E) is used, it is preferable that (A) and (E) are thoroughly mixed. This is because if a component having an acrylic group is unevenly present, areas where curing progresses and areas where it does not may be seen on the coating surface. For this reason, it is preferable to mix (A) and (E) by stirring for 30 seconds or more. Furthermore, when mixing (A) and (E), component (D), which will be described later, may be mixed and dispersed.

[0031] Components (A) and (E) can be obtained by blending the raw materials for the respective siloxane units, polymerizing them with an acid or alkali catalyst, and then equilibrating them. For example, component (A) can be obtained by blending the raw materials for the respective siloxane units, M2, M Vi 2, D4, D5, D Vi Siloxane raw materials such as 4 are often heated and equilibrated using an alkaline catalyst such as KOH. It is preferable to use an alkaline catalyst for the synthesis of (A) and an acid catalyst for the synthesis of (E). This is because, for example, when a platinum catalyst is added to produce a cured coating for the final release sheet silicone, any remaining alkaline catalyst used in the synthesis of (A) can poison the platinum catalyst and hinder curing. Even residual alkaline catalysts at the ppb level can inhibit curing. Therefore, using an acid catalyst to synthesize (E) allows trace amounts of the alkaline catalyst to become salts, thereby suppressing curing inhibition. Examples of alkaline catalysts include KOH, NaOH, potassium siliconate, cesium hydroxide, potassium methoxide, potassium t-butoxide, potassium silanolate, tetramethylammonium hydride, and tetrabutylphosphonium hydroxide. Examples of acid catalysts include sulfuric acid, hydrochloric acid, methanesulfonic acid, and trifluoromethanesulfonic acid.

[0032] Because component (A) maintains a stable structure even after prolonged vacuum concentration at high temperatures, the amount of cyclic low-molecular-weight siloxanes can be reduced, and the total amount of cyclooctamethyltetrasiloxane, cyclodecamethylpentasiloxane, and cyclododecamethylhexasiloxane (hereinafter sometimes referred to as D4, D5, and D6) in component (A) can be 1,000 ppm (mass) or less (0.1 mass% or less), preferably 1 to 150 ppm, and more preferably 1 to 100 ppm. Furthermore, when component (E) is used, the total content of cyclooctamethyltetrasiloxane, cyclodecamethylpentasiloxane, and cyclododecamethylhexasiloxane is preferably 1,000 ppm (mass) or less (0.1 mass% or less), more preferably 800 ppm or less, of the total amount of components (A) and (E).

[0033] The amount of cyclic low-molecular-weight siloxanes is determined by gas chromatography using a capillary column, heating conditions of 50°C to 280°C, helium as the carrier gas, an FID as the detector, and a sample injection volume of 2 μL. When component (E) is used in component (A), as long as the total amount of the cyclic siloxanes in the combined total of components (A) and (E) is within the above range, the total content of the cyclic siloxanes in the silicone composition will be in the range of 0.1 to 850 ppm, which is extremely effective.

[0034] [Component (B)] Component (B) is an organohydrogenpolysiloxane having an average of three or more silicon-bonded hydrogen atoms (Si—H groups) per molecule, and can be used alone or in appropriate combination of two or more. The number of silicon-bonded hydrogen atoms (Si—H groups) per molecule is preferably 3 to 200, and more preferably 10 to 200. If the Si—H group content is too low, curing properties and adhesion tend to deteriorate, while if it is too high, the release force may increase. An organopolysiloxane crosslinked product is formed by addition reaction of the Si—H groups of the organohydrogenpolysiloxane with the alkenyl groups of component (A). The Si—H group content is preferably from 0.001 to 3.5 mol / 100 g, more preferably from 0.01 to 2.5 mol / 100 g, and even more preferably from 0.02 to 2.0 mol / 100 g.

[0035] The organohydrogensiloxane of component (B) is preferably a siloxane represented by the following formula (3): r MH s D t D H u T v T H w Q x (3) (Where M is RSiO 1 / 2 , M H is R2HSiO 1 / 2 , D is RSiO 2 / 2 , D H is RHSiO 2 / 2 , T is RSiO 3 / 2 , T H is HSiO 3 / 2 , Q is SiO 4 / 2 R is independently an unsubstituted or substituted monovalent hydrocarbon group of 1 to 12 carbon atoms that does not have an aliphatic unsaturated bond. r, s, t, and v are independently 0 or a positive number, u is 0 or a positive number of 200 or less, w is 0 or a positive number of 10 or less, and x is 0 or a positive number of 10 or less, provided that s, u, and w are not simultaneously 0, and 3≦s+u+w≦200.

[0036] In the above formula (3), R can be exemplified as R in the above formula (1), and among these, an alkyl group having 1 to 8 carbon atoms is preferred. In formula (3), r, s, t, and v are each independently 0 or a positive number, with r preferably being 0 or a positive number of 10 or less, s preferably being 0 or a positive number of 10 or less, t preferably being 0 or a positive number of 100 or less, and v being 0 or a positive number of 10 or less, preferably 0 or a positive number of 5 or less. Furthermore, u is 0 or a positive number of 200 or less, preferably 2 to 100, and more preferably 10 to 80. w is 0 or a positive number of 10 or less, preferably 0 or a positive number of 5 or less. Furthermore, s, u, and w cannot simultaneously be 0, and s + u + w is 3 to 100, preferably a positive number of 10 to 80. x is a positive number of 0 or 10 or less, preferably 0 or a positive number of 5 or less.

[0037] Specific examples of the organohydrogenpolysiloxane of component (B) include polysiloxanes containing hydrogensilyl groups at both ends, polysiloxanes containing hydrogensilyl groups in the side chain, polysiloxanes containing hydrogensilyl groups at one end and in the side chain, and polysiloxanes containing hydrogensilyl groups at both ends and in the side chain.

[0038] The structural formula is M H 2Dt, M2D H u, M2DtD H u, M H 2DtDHu,M H 3DtT1,M H 4DtT2, MiDtD H uT H (M, MH, D, DH, T, TH, r, t, u, and w are the same as above. The same applies below.) Further specific structural examples include M H 2D 10 , M H 2D 100 , M2D 27 D H 3. M2D 97 D H 3. M2D 26 D H 4. M2D 25 D H 5. M2D 24 D H 6. M2D 96 D H 4. M2D 95 D H 5. M H 3D 100 T1, M H 4D 100 T2, M H 2D 97 DH1, M2D 30 D H 5Q1, M H 2D 95 D H 3. M3D 93 D H 3T H The first prize can be mentioned.

[0039] The weight-average molecular weight of component (B) is preferably 194 to 20,000, and more preferably 874 to 5,000. When the weight-average molecular weight of component (B) is 194 or more, adhesion is further improved. Furthermore, by making it 20,000 or less, curability is further improved from the standpoint of reactivity, and a decrease in residual adhesion rate and an increase in peel force due to insufficient curing are further suppressed.

[0040] The kinematic viscosity of component (B) at 25°C measured using an Ostwald viscometer is 2 to 500 mm 2 / s is preferred, and 3 to 300 mm 2 / s is more preferable, and 5 to 200 mm 2 / s is more preferable. 2 By setting the thickness to 500 mm / s or more, the adhesion to the substrate is further improved. 2 By setting the curing rate to 1 / s or less, the curing property is further improved in terms of reactivity, and the decrease in residual adhesion rate and the increase in peel force due to insufficient curing are further suppressed.

[0041] The amount of component (B) is an amount corresponding to 1 to 5 times the number of Si-H groups (moles) relative to the total number of alkenyl groups (moles) in component (A), with an amount corresponding to 1.2 to 3 being preferred, and an amount corresponding to 1.3 to 2 being more preferred. Considered as the amount of Si-H functional groups, an amount corresponding to 1 to 5 corresponds to 0.016 to 3.5 mol / 100 g. If the amount of component (B) is too small, curability and adhesion tend to be insufficient. If the amount is too large, the amount of remaining Si-H groups increases, resulting in an increased release force, and the Si-H groups decrease over time, resulting in a decrease in release force over time. When component (E) is included, the above ratio refers to the amount relative to the number of alkenyl groups (moles) in components (A) and (E).

[0042] [Component (C)] As the platinum group metal catalyst (C) of the present invention, known catalysts used as addition reaction catalysts can be used.Such platinum group metal catalysts include, for example, platinum, palladium, rhodium, ruthenium, etc. catalysts, and among these, platinum catalysts are particularly preferably used.Such platinum catalysts include, for example, platinum compounds, complexes of platinum and vinylsiloxane, etc., alcohol solutions or aldehyde solutions of chloroplatinic acid, complex salts of chloroplatinic acid and various olefins, complexes of chloroplatinic acid and vinylsiloxane, etc.

[0043] The amount of component (C) is 1 to 200 ppm, preferably 1 to 100 ppm, more preferably 2 to 70 ppm, even more preferably 3 to 50 ppm, and particularly preferably 7 to 25 ppm, calculated as the mass of platinum group metal relative to the total composition. In the present invention, curing is possible with a small amount of catalyst, so a smaller amount can be used.

[0044] [Component (D)] The addition reaction inhibitor (D) of the present invention is an optional component that controls the catalytic activity of platinum group metal catalysts. Examples include various organic nitrogen compounds, organic phosphorus compounds, acetylene compounds, oxime compounds, and organic chloro compounds. Among these, a mixture containing an acetylene group-containing compound with a hydroxyl group and a silane with an acetylene group is preferred. The reason for this superiority is thought to be as follows: Although the acetylene group-containing compound with a hydroxyl group inherently has excellent addition reaction inhibitory effects, it is insoluble in siloxane compounds, preventing this ability from being fully utilized. Therefore, by using the siloxane compound in combination with a compatible acetylene group-containing silane, the compatibility of the acetylene group-containing compound with a hydroxyl group is improved, thereby fully utilizing the inherent inhibitory effect. Furthermore, upon heating, the acetylene group-containing compound with a hydroxyl group forms an azeotrope with the acetylene group-containing silane, which has a low boiling point, and the inhibitor disappears from the composition at temperatures lower than usual.

[0045] Examples of the acetylene group-containing compound having a hydroxyl group include 1-ethynyl-1-cyclohexanol, 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-pentyn-3-ol, and 2-phenyl-3-butyn-2-ol.

[0046] Examples of silanes having an acetylene group include reaction products of acetylene compounds such as 1,1-dimethylpropynyloxytrimethylsilane and dimethylbis(1,1-dimethyl-2-propynyloxy)silane with alkoxysilanes.

[0047] The amount of component (D), when blended, is 0.01 to 10 parts by mass, preferably 0.01 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass, per 100 parts by mass of the total of components (A), (B), and (C).

[0048] [Optional Components] The organopolysiloxane composition of the present invention can contain components that are typically added to organopolysiloxane compositions for release papers or films, provided that the effects of the present invention are not impaired.

[0049] Examples of optional additive components include high molecular weight linear organopolysiloxanes other than components (A) and (B) for the purpose of imparting slipperiness, silicone resins having aryl groups other than components (A) and (B) for the purpose of adjusting release force, silicone resins, silica, and low molecular weight organopolysiloxanes having neither hydrogen atoms nor alkenyl groups bonded to silicon atoms.

[0050] [Production Method] The organopolysiloxane composition of the present invention can be obtained, for example, by mixing the above-mentioned components (A) and, if necessary, (E), (B), and (C). This method includes a step of mixing (A), if necessary, (E), and (B), and may further include mixing, if necessary, component (D). Alternatively, (A) and, if necessary, (E) may be premixed. When component (D) is added, it is preferable to include a step of premixing and dispersing component (D) in (A) and, if necessary, component (E) or (B). Specifically, component (D), which is incompatible with organopolysiloxane, is premixed and dispersed in (A) and, if necessary, component (E) or (B), and homogeneously dispersed. The remaining components are then mixed, thereby achieving a homogeneous dispersion of the addition reaction inhibitor.

[0051] [Addition Reaction Curable Organopolysiloxane Composition] The organopolysiloxane composition of the present invention is an addition reaction curable type. Because of the above-mentioned properties, it is suitable for use in release paper or release film. The kinematic viscosity of the addition reaction curable organopolysiloxane composition of the present invention at 25°C measured with an Ostwald viscometer is 500 mm 2 / s or less is preferable, and 10 to 450 mm 2 / s is more preferable, and 50 to 430 mm 2 If the kinematic viscosity is too low, the coating amount may be small, and if it is too high, the coating amount may vary and a large amount of mist may be generated. 2 / s or more, a more sufficient coating amount can be obtained, and the viscosity is 450 mm 2 If the coating rate is 1 / s or less, it is possible to further suppress the occurrence of variations in the coating amount and the generation of a large amount of mist.

[0052] The release force of the organopolysiloxane composition of the present invention is measured using a release sheet that is a cured product of the organopolysiloxane composition. Specifically, the release force can be measured at a peel rate of 150 m / min according to FINAT Test Method No. 4 using TESA-7475 tape (Tesa SE), and at a peel rate of 0.3 m / min according to FINAT Test Method No. 3. The FINAT Test Method refers to the test method listed in the FINAT Technical Handbook published by the FINAT Technical Committee.

[0053] FINAT Test Method No. 4 is a high-speed peel force measurement method specified in the above FINAT Test Method, and the peel speed refers to 10 m / min to 300 m / min. In this application, the peel speed for high-speed peel force is set to 150 m / min. The peel force in FINAT Test Method No. 4 is preferably 0.05 N / 25 mm to 0.25 N / 25 mm, and more preferably 0.08 N / 25 mm to 0.22 N / 25 mm.

[0054] FINAT Test Method No. 3 is a low-speed peel force measurement method specified in the above FINAT Test Method, and the peel speed is 0.3 m per minute. The peel force in FINAT Test Method No. 3 is preferably 0.1 N / 25 mm to 0.5 N / 25 mm, and more preferably 0.15 N / 25 mm to 0.45 N / 25 mm.

[0055] The release strength according to FINAT Test Method No. 4 is preferably less than 2.5, more preferably greater than 1.2 but less than 2.5, and even more preferably greater than 1.3 but less than 2.2, relative to the release strength according to FINAT Test Method No. 3. Numerical values ​​within the above ranges are effective as organopolysiloxane compositions for release sheets, with release strengths that exhibit little dependency on peel speed. Furthermore, the above release strengths make it possible to provide organopolysiloxane compositions for release sheets that exhibit light release at both low-speed peeling of 0.3 m / min and high-speed peeling of 150 m / min, and that are capable of forming cured coatings with low speed dependency of release strength.

[0056] [Uses and Methods of Use] The organopolysiloxane composition of the present invention is applied to a sheet-like substrate, such as paper or plastic film, using a coating roll or the like, and then heat-cured by a conventional method. In this way, a silicone cured coating (sheet) of the organopolysiloxane composition of the present invention is formed on one side of the sheet-like substrate, and is suitably used as a release sheet for release paper or release film. Examples of paper substrates include glassine paper, polyethylene-laminated paper, polyvinyl alcohol resin-coated paper, clay-coated paper, kraft paper, and supercalendered kraft paper. Examples of plastic film substrates include films of polyesters such as polyethylene, polypropylene, and polyethylene terephthalate.

[0057] [For release paper or release film] A release paper or release film can be obtained having a release sheet made of a cured product of the organopolysiloxane composition of the present invention. For example, the amount of the organopolysiloxane composition applied may be an amount sufficient to form a cured silicone film on the surface of a sheet-like substrate, and may be, for example, 0.1 to 5.0 g / m 2 Applying too much may actually result in a decrease in release performance. The temperature during heat curing varies depending on the type of substrate and the amount of coating, but a cured coating can be formed on the substrate by heating at 60 to 200°C, preferably 100 to 190°C, more preferably 120 to 180°C for 1 to 60 seconds, and even more preferably 2 to 40 seconds.

[0058] 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. 29 The viscosity was determined by Si-NMR, and the value was measured at 25°C using a BM type rotational viscometer, and the kinematic viscosity was measured at 25°C using an Ostwald type viscometer.

[0059] [Raw Materials Used] Component (A) (A-1) Multi-branched terminal vinyl group-containing siloxane: M Vi 6D 230 T4M Vi :(CH2=CH)(CH3)2SiO 1 / 2 D: (CH3)2SiO 2 / 2 T: (CH3)SiO 3 / 2 <Synthesis method> A copolymer having 12 branched chains, 14 molecular chain ends capped with dimethylvinylsiloxy groups, a vinyl value of 0.67 mol / 100 g, and a viscosity of 20 mm 2 / s methylvinylpolysiloxane (M Vi 12 T 10 ) 0.04 moles, 1,3-divinyltetramethyldisiloxane (M Vi 2) 0.06 moles of octamethylcyclotetrasiloxane (D4), 5.75 moles of siliconate of KOH, and potassium hydroxide were added to give a siliconate of 150 ppm, and polymerization and equilibration were carried out for 6 hours at 150°C under a nitrogen atmosphere. Then, ethylene chlorohydrin was added in an amount twice the molar amount of potassium, and neutralization was carried out for 2 hours at 150°C. After that, the mixture was concentrated under reduced pressure for 3 hours at 120°C and 20 mmHg, and then 5% by mass of activated carbon Shirasagi A (manufactured by Osaka Gas Chemicals Co., Ltd.) was added. After stirring for 2 hours, the mixture was filtered using a filter plate NA10 (manufactured by ADVANTEC Co., Ltd.). The resulting siloxane was 29 Structural formula by Si-NMR: M Vi 6D 230 Both ends of the molecular chain represented by T4 are blocked with dimethylvinylsiloxy groups, and the rest are made up of (CH3)2SiO units and (CH3)SiO 3 / 2 It consists of units, has a vinyl value of 0.034 mol / 100 g, and a kinematic viscosity of 280 mm 2 The organopolysiloxane was

[0060] (A-2) Multi-branched terminal vinyl group-containing siloxane: M Vi 5D 170 T3M Vi :(CH2=CH)(CH3)2SiO 1 / 2 D: (CH3)2SiO 2 / 2 T: (CH3)SiO 3 / 2 <Synthesis method> A copolymer having 12 branched chains, 14 molecular chain ends capped with dimethylvinylsiloxy groups, a vinyl value of 0.67 mol / 100 g, and a viscosity of 20 mm 2 / s methylvinylpolysiloxane (M Vi 12 T 10 ) 0.03 mole, 1,3-divinyltetramethyldisiloxane (M Vi 2) 0.07 moles of octamethylcyclotetrasiloxane (D4), 4.25 moles of siliconate of KOH, and potassium hydroxide were added to give a siliconate of 150 ppm, and polymerization and equilibration were carried out for 6 hours at 150°C under a nitrogen atmosphere. Then, ethylene chlorohydrin was added in an amount twice the molar amount of potassium, and neutralization was carried out for 2 hours at 150°C. After that, the mixture was concentrated under reduced pressure for 3 hours at 120°C and 20 mmHg, and then 5% by mass of activated carbon Shirasagi A (manufactured by Osaka Gas Chemicals Co., Ltd.) was added. After stirring for 2 hours, the mixture was filtered using a filter plate NA10 (manufactured by ADVANTEC Co., Ltd.). The resulting siloxane was 29 Structural formula by Si-NMR: M Vi 5D 170 Both ends of the molecular chain represented by T3 are blocked with dimethylvinylsiloxy groups, and the rest are made up of (CH3)2SiO units and (CH3)SiO 3 / 2 It consists of units, has a vinyl value of 0.037 mol / 100 g, and a kinematic viscosity of 200 mm 2 The organopolysiloxane was

[0061] (a-3: Comparative product) Siloxane containing vinyl groups at both ends: M Vi 2D 155 M Vi :(CH2=CH)(CH3)2SiO 1 / 2 D: (CH3)2SiO 2 / 2 <Synthesis Method> 1,3-divinyltetramethyldisiloxane (M Vi2) 0.1 moles of octamethylcyclotetrasiloxane (D4) and 3.875 moles of octamethylcyclotetrasiloxane (D4) were added with KOH (300 ppm), and polymerization and equilibration were carried out at 150°C for 6 hours. After that, ethylene chlorohydrin was added in an amount 1.5 times the moles of KOH, and neutralization was carried out at 150°C for 3 hours. After vacuum concentration at 120°C and 20 mmHg for 3 hours, 5% by mass of activated carbon Shirasagi A (Osaka Gas Chemicals Co., Ltd.) was added, and the mixture was stirred for 2 hours and then filtered using a filter plate NA10 (Advantec Corporation). The resulting siloxane was 29 Structural formula by Si-NMR: M Vi 2D 155 Both ends of the molecular chain are blocked with dimethylvinylsiloxy groups, and all units other than those at the ends are (CH)SiO units. The vinyl value is 0.017 mol / 100 g, and the kinematic viscosity is 440 mm. 2 The organopolysiloxane was

[0062] (a-4: Comparative product) Siloxane containing vinyl groups at both ends: M Vi 2D 100 M Vi :(CH2=CH)(CH3)2SiO 1 / 2 D: (CH3)2SiO 2 / 2 <Synthesis Method> 1,3-divinyltetramethyldisiloxane (M Vi 2) 0.1 moles of octamethylcyclotetrasiloxane (D4) and 2.5 moles of octamethylcyclotetrasiloxane (D4) were added with KOH (300 ppm), and polymerization and equilibration were carried out at 150°C for 6 hours. After that, 1.5 times the moles of ethylene chlorohydrin as KOH was added and neutralization was carried out at 150°C for 3 hours. After vacuum concentration at 120°C and 20 mmHg for 3 hours, 5% by mass of activated carbon Shirasagi A (Osaka Gas Chemicals Co., Ltd.) was added, and the mixture was stirred for 2 hours and then filtered using a filter plate NA10 (Advantec Co., Ltd.). The resulting siloxane was 29 Structural formula by Si-NMR: M Vi 2D 100 Both ends of the molecular chain are blocked with dimethylvinylsiloxy groups, and all units other than those at the ends are (CH3)2SiO units. The vinyl value is 0.026 mol / 100 g, and the kinematic viscosity is 200 mm 2 The organopolysiloxane was obtained.

[0063] (a-5: Comparative product) Branched vinyl-terminated siloxane: M Vi 3D 155 T1M Vi :(CH2=CH)(CH3)2SiO 1 / 2 D: (CH3)2SiO 2 / 2 T: (CH3)SiO 3 / 2 <Synthesis Method> Methyltris(dimethylvinylsiloxy)silane (M Vi To 0.1 moles of octamethylcyclotetrasiloxane (D4), a siliconate of KOH was added to give a potassium hydroxide content of 150 ppm. Polymerization and equilibration were carried out for 6 hours at 150°C under a nitrogen atmosphere, followed by the addition of ethylene chlorohydrin in an amount twice the molar amount of potassium, and neutralization for 2 hours at 150°C. The mixture was then concentrated under reduced pressure for 3 hours at 120°C and 20 mmHg, after which 5% by mass of activated carbon Shirasagi A (Osaka Gas Chemicals Co., Ltd.) was added, stirred for 2 hours, and then filtered using a filter plate NA10 (Advantec Corporation). The resulting siloxane was 29 Structural formula by Si-NMR: M Vi 3D 160 Both ends of the molecular chain represented by T1 are blocked with dimethylvinylsiloxy groups, and the rest are made up of (CH3)2SiO units and (CH3)SiO 3 / 2 It consists of units, has a vinyl value of 0.026 mol / 100 g, and a kinematic viscosity of 250 mm 2 The organopolysiloxane was

[0064] Component (B) (B-1) Methylhydrogenpolysiloxane Both molecular chain terminals are blocked with trimethylsiloxy groups, and all units other than those at the terminals are (CH3)HSiO units. Si-H group content is 1.54 mol / 100 g, and kinematic viscosity is 32 mm 2 / s Methyl hydrogen polysiloxane

[0065] Component (C) (C-1) Platinum group metal catalyst: complex of platinum and vinylsiloxane

[0066] Component (D) (D-1) 1-ethynyl-1-cyclohexanol (D-2) dimethylbis(1,1-dimethyl-2-propynyloxy)silane

[0067] Component (E) (E-1) Siloxane containing side chain acrylic groups and vinyl groups at both ends: M Vi 2D 90 D Ac 9 1,3-divinyltetramethyldisiloxane (M Vi 2) 0.1 mole, octamethylcyclotetrasiloxane (D4) 2.25 moles and tetramethyltetraacryloxycyclotetrasiloxane (D Ac 4) To 0.225 mol of siloxane, sulfuric acid was added in an amount of 10% by weight of the total siloxane, and polymerization and equilibration were carried out at room temperature for 4 hours. Water was added in an amount of 2% by weight of the total siloxane, and 82.5% by weight of toluene was added, and the mixture was stirred for 2 hours and then allowed to stand. Once the organic and aqueous layers separated, the aqueous layer was collected and discarded. Approximately 80% by weight of 10% aqueous sodium sulfate was added to the organic layer, and the mixture was stirred for 30 minutes and then allowed to stand. The separated aqueous layer was then discarded. Approximately 3% by weight of sodium sulfate was added to the total siloxane, and the mixture was dehydrated and then filtered through a filter plate. The resulting siloxane was subjected to vacuum stripping at 120°C and 10 mmHg, and had a viscosity of 231 mmHg. 2 The vinyl value of the present invention, as measured by the Hanus method in accordance with JIS K 0070, was 0.024 mol / 100 g.

[0068] Example 1 100 parts by mass of methylvinylpolysiloxane (A-1) as component (A), 1 part by mass of 1-ethynylcyclohexanol (D-1) as component (D), and 0.5 parts by mass of dimethylbis(1,1-dimethyl-2-propynyloxy)silane (D-2) as component (D) were added to the mixture, which was stirred for 10 minutes until uniform. 3.53 parts by mass of methylhydrogenpolysiloxane (B-1) as component (B) was then added and mixed for 10 minutes. 2 parts by mass of platinum and vinylsiloxane complex (C-1) as component (C) was then added to the mixture, so that the platinum concentration was 50 ppm, calculated as atomic mass, relative to the total mass of components (A), (B), and (D). The mixture was stirred for 1 minute until uniform, yielding a composition with an H / Vi (ratio of Si—H groups in the composition to alkenyl groups in the composition) of 1.6. The amount of cyclic low molecular weight siloxanes (D4+D5+D6) contained in component (A) was 40 ppm.

[0069] Example 2 100 parts by mass of methylvinylpolysiloxane (A-2) as component (A), 1 part by mass of 1-ethynylcyclohexanol (D-1) as component (D), and 0.5 parts by mass of dimethylbis(1,1-dimethyl-2-propynyloxy)silane (D-2) were added to the mixture, which was stirred for 10 minutes until uniform. 3.85 parts by mass of methylhydrogenpolysiloxane (B-1) as component (B) was then added and mixed for 10 minutes. A composition with an H / Vi = 1.6 was prepared in the same manner as in Example 1, except that the amount of platinum and vinylsiloxane complex (C-1) as component (C) was increased to 2 parts by mass relative to the total mass of components (A), (B), and (D) so that the platinum atomic mass equivalent was 50 ppm. The amount of cyclic low molecular weight siloxanes (D4 + D5 + D6) contained in components (A) and (E) was 50 ppm.

[0070] Example 3 A composition having an H / Vi ratio of 1.6 was prepared in the same manner as in Example 1, except that the component (A) contained 99.5 parts by mass of methylvinylpolysiloxane (A-1), the component (E) contained 0.5 parts by mass of a siloxane (E-1) containing vinyl groups at both terminal ends of a side chain acrylic group, the component (B) contained 3.53 parts by mass of methylhydrogenpolysiloxane (B-1), the component (C) contained 1 part by mass of a platinum and vinylsiloxane complex (C-1) relative to the total mass of components (A), (B), (D), and (E) so that the platinum atomic mass was 25 ppm. The amount of cyclic low molecular weight siloxanes (D4 + D5 + D6) contained in the component (A) was 50 ppm.

[0071] Example 4 A composition having an H / Vi ratio of 1.6 was prepared in the same manner as in Example 1, except that the component (A) contained 99.5 parts by mass of methylvinylpolysiloxane (A-2), the component (E) contained 0.5 parts by mass of a siloxane (E-1) containing vinyl groups at both terminal ends of a side chain acrylic group, the component (E) contained 3.84 parts by mass of methylhydrogenpolysiloxane (B-1), the component (B) contained 3.84 parts by mass of a platinum and vinylsiloxane complex (C-1), the component (C) contained 1 part by mass of platinum and vinylsiloxane complex (C-1) relative to the total mass of components (A), (B), (D), and (E) so that the platinum atomic mass was 25 ppm. The amount of cyclic low molecular weight siloxanes (D4 + D5 + D6) contained in components (A) and (E) was 60 ppm.

[0072] Comparative Example 1 A composition having an H / Vi ratio of 1.6 was prepared in the same manner as in Example 1, except that 100 parts by mass of methylvinylpolysiloxane (a-3) as component (A), 1.77 parts by mass of methylhydrogenpolysiloxane (B-1) as component (B), 1 part by mass of 1-ethynylcyclohexanol (D-1) and 0.5 parts by mass of dimethylbis(1,1-dimethyl-2-propynyloxy)silane (D-2) as component (D) were added and stirred for 10 minutes, and then 2 parts by mass of a platinum / vinylsiloxane complex was added as component (C) so that the platinum atomic mass equivalent was 50 ppm relative to the total mass of components (A), (B), and (D). The amount of cyclic low molecular weight siloxanes (D4 + D5 + D6) contained in component (A) was 20 ppm.

[0073] Comparative Example 2 A composition having an H / Vi ratio of 1.6 was prepared in the same manner as in Example 1, except that 100 parts by mass of methylvinylpolysiloxane (a-4) as component (A), 2.70 parts by mass of methylhydrogenpolysiloxane (B-1) as component (B), 1 part by mass of 1-ethynylcyclohexanol (D-1) and 0.5 parts by mass of dimethylbis(1,1-dimethyl-2-propynyloxy)silane (D-2) as component (D) were added and stirred for 10 minutes, and then 2 parts by mass of a platinum / vinylsiloxane complex was added as component (C) so that the platinum atomic mass equivalent was 50 ppm relative to the total mass of components (A), (B), and (D). The amount of cyclic low molecular weight siloxanes (D4 + D5 + D6) contained in component (A) was 30 ppm.

[0074] Comparative Example 3 A composition having an H / Vi ratio of 1.6 was prepared in the same manner as in Example 1, except that 100 parts by mass of methylvinylpolysiloxane (a-5) as component (A), 2.70 parts by mass of methylhydrogenpolysiloxane (B-1) as component (B), 1 part by mass of 1-ethynylcyclohexanol (D-1) and 0.5 parts by mass of dimethylbis(1,1-dimethyl-2-propynyloxy)silane (D-2) as component (D) were added and stirred for 10 minutes, and then 2 parts by mass of a platinum / vinylsiloxane complex was added as component (C) so that the platinum atomic mass equivalent was 50 ppm relative to the total mass of components (A), (B), and (D). The amount of cyclic low molecular weight siloxanes (D4 + D5 + D6) contained in component (A) was 30 ppm.

[0075] Comparative Example 4 A composition having an H / Vi ratio of 1.6 was prepared in the same manner as in Example 1, except that 99.5 parts by mass of methylvinylpolysiloxane (A-3) as component (A), 1.77 parts by mass of methylhydrogenpolysiloxane (B-1) as component (B), 1 part by mass of 1-ethynylcyclohexanol (D-1) as component (D), 0.5 parts by mass of dimethylbis(1,1-dimethyl-2-propynyloxy)silane (D-2) as component (D), and 0.5 parts by mass of a siloxane (E-1) containing vinyl groups at both terminal ends of a side chain acrylic group were added and stirred for 10 minutes. The amount of a platinum / vinylsiloxane complex as component (C) was increased to 1 part by mass so that the platinum atomic mass was 25 ppm relative to the total mass of components (A), (B), and (D). The amount of cyclic low molecular weight siloxanes (D4 + D5 + D6) contained in components (A) and (E) was 30 ppm.

[0076] The organopolysiloxane compositions obtained in the above examples were evaluated as follows, and the results are shown in the table.

[0077] [Appearance of Coating Liquid] The appearance of the coating liquid (immediately after mixing) and the appearance of the coating liquid (after leaving it standing for 8 hours) were evaluated visually.

[0078] [Peeling Force] The organopolysiloxane composition was applied to the metal roll of an offset transfer machine (manufactured by IHI Machine Systems Co., Ltd.), and the metal roll was brought into contact with a rubber roll and rotated for 45 seconds to uniformly spread the composition. The composition was then transferred from the rubber roll to glassine paper (manufactured by Sappi). The glassine paper onto which the composition had been transferred was heated in a hot air dryer at 120°C for 30 seconds to form a peeling force of 0.9 to 1.1 g / m. 2 After aging for 24 hours at 25°C in this state, TESA-7475 adhesive tape (TESA SE) was attached to the cured coating surface of the release paper (the side transferred from the rubber roll), and cut into a size of 2.5 cm x 18 cm to prepare a test piece. This was sandwiched between glass plates and subjected to a pressure of 70 gf / cm at 25°C. 2 The test piece was aged for 20 hours under a load of 0.3 m / min. After aging, one end of the test piece was peeled off, and the end of the adhesive tape was pulled at an angle of 180 degrees to the glassine paper at peeling rates of 0.3 m / min and 150 m / min. The force required to peel the tape (i.e., "peeling force") (gf / 25 mm) was measured using a tensile tester (Shimadzu Corporation, Model AGS-50G) at a peeling rate of 0.3 m / min and a tensile tester (ChemInstruments, Inc., Model HSR-2000) at a peeling rate of 150 m / min. The ratio of the peeling force when the TESA-7475 tape was peeled at a peeling rate of 150 m / min (high speed) to the peeling force when the TESA-7475 tape was peeled at a peeling rate of 0.3 m / min (low speed) is shown in the table. The lower this ratio, the less speed-dependent the release force becomes, which means that a cured coating can be formed.

[0079] [Residual Adhesion Rate] The TESA-7475 adhesive tape after the above peel force measurement was adhered to a stainless steel plate, and a load was applied by moving a 2 kg roller back and forth once. After leaving it for 30 minutes, one end of the TESA-7475 adhesive tape was peeled off, and the end was pulled in a direction at an angle of 180 degrees to the polyester film. The force required to peel the tape at a peeling rate of 0.3 m / min (hereinafter referred to as "peel force A", N / 25 mm) was measured. As a blank, unused TESA-7475 adhesive tape was adhered to a polyester film, and a load was applied by moving a 2 kg roller back and forth once in the same manner as above. After leaving it for 30 minutes, one end of the TESA-7475 adhesive tape was peeled off, and the end was pulled in a direction at an angle of 180 degrees to the polyester film. The force required to peel the tape at a peeling rate of 0.3 m / min (hereinafter referred to as "peel force B", N / 25 mm) was measured. The residual adhesion rate (%) was calculated by (value of peel force A) / (value of peel force B)×100.

[0080] [Curability] Using the same method as in the peel force measurement, each organopolysiloxane composition was transferred to glassine paper ASP using an offset transfer machine. The glassine paper onto which the organopolysiloxane composition had been transferred was heated in a hot air dryer at 120°C for 30 seconds to form a film with a thickness of 0.9 to 1.1 g / m. 2 The release paper was removed from the dryer and the cured coating surface was immediately rubbed strongly with the index finger 10 times, and red magic marker was applied to observe the ink thickness and the state of the cured coating. The results were evaluated based on the following criteria: "○" - Almost no finger marks visible, "△" - Light finger marks visible, "×" - Dark finger marks visible

[0081] [Amount of Silicone (Organopolysiloxane) Transfer] In the same manner as in the peel force measurement, a 38 μm thick polyester film was placed on the surface of a cured film of organopolysiloxane composition formed on the surface of glassine paper, and after 20 hours of pressure bonding at room temperature under a pressure of 0.98 MPa, the polyester film was removed from the cured film. An oil-based ink (trade name: Magic Ink, manufactured by Teranishi Chemical Industry Co., Ltd.) was applied to the surface of the polyester film that had been in contact with the cured film, and silicone transfer was evaluated based on the degree of repellency. The results were evaluated based on the following criteria: "○": No ink repellency (no or very little silicone transfer); "×": Ink repellency (high silicone transfer).

[0082] [Amount of low molecular weight siloxanes contained in (A)] 0.1 g of component (A) was extracted with 10 mL of acetone and analyzed by gas chromatography to quantify the total amount of cyclic siloxanes (cyclooctamethyltetrasiloxane, cyclodecamethylpentasiloxane, and cyclododecamethylhexasiloxane). The measurement conditions were a capillary column, heating conditions of 50°C to 280°C, helium carrier gas, FID detector, and a sample injection volume of 2 μL.

[0083]

[0084]

Claims

1. An organopolysiloxane composition for release sheets, comprising the following components (A), (B), and (C): (A) 100 parts by mass of a hyperbranched organopolysiloxane having an average of four or more alkenyl groups per molecule; (B) an organohydrogensiloxane having an average of three or more silicon-bonded hydrogen atoms per molecule: in an amount such that the ratio of the number of SiH groups in component (B) to the total number of alkenyl groups in component (A) is 1 to 5; and (C) a platinum group metal catalyst: in an amount equivalent to 1 to 200 ppm by mass of platinum group metal relative to the total composition.

2. The organopolysiloxane composition for release sheets according to claim 1, further comprising (D) an addition reaction inhibitor in an amount of 0.01 to 10 parts by weight per 100 parts by weight of the total of components (A), (B), and (C).

3. The organopolysiloxane composition for release sheets according to claim 2, wherein component (D) is a mixture containing an acetylene group-containing compound having a hydroxyl group and a silane having an acetylene group.

4. The organopolysiloxane composition for release sheets according to claim 1, further comprising (E) an organopolysiloxane having an average of 0.1 or more alkenyl groups and an average of 0.1 to 20 (meth)acrylic groups per molecule, wherein the mass ratio of (A) to (E) is (A):(E) is 50-99.9:50-0.

1.

5. The component (A) is represented by the following formula (1): M a M Vi b D c D Vi d T e T Vi f Q g (1) (Where M is RSiO 1 / 2 , M Vi is R2PSiO 1 / 2 , D is RSiO 2 / 2 , D Vi is RPSiO 2 / 2 , T is RSiO 3 / 2 , T Vi is PSiO 3 / 2 , Q is SiO 4 / 2 R is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and no aliphatic unsaturated bond. P is -(CH2) h and an alkenyl group represented by the formula: -CH=CH2 (h is an integer of 0 to 6). a, b, d, and f are each independently 0 or a positive number, provided that b, d, and f are not all 0 at the same time, a+b≧4, 4≦b+d+f≦500, c is a positive number from 10 to 2,700, e is 0 or a positive number of 200 or less, and g is a positive number of 0 or 100 or less, provided that e, f, and g are not all 0 at the same time, and e+f+g≧2. The organopolysiloxane composition for release sheets according to claim 1, which contains an average of four or more alkenyl groups per molecule and has an alkenyl group content of 0.001 mol / 100 g or more and less than 0.7 mol / 100 g.

6. The organopolysiloxane composition for release sheets according to claim 1, wherein component (A) is a hyperbranched organopolysiloxane having an average of 4 to 8 alkenyl groups per molecule.

7. The component (A) has a kinematic viscosity of 100 mm at 25°C. 2 / s or more 450mm 2 2. The organopolysiloxane composition for release sheets according to claim 1, which is a hyperbranched organopolysiloxane having a molecular weight of less than 1 / s.

8. The component (B) is represented by the following formula (3): M r MH s D t D H u T v T H w Q x (3) (Where M is RSiO 1 / 2 , M H is R2HSiO 1 / 2 , D is RSiO 2 / 2 , D H is RHSiO 2 / 2 , T is RSiO 3 / 2 , T H is HSiO 3 / 2 , Q is SiO 4 / 2 R is independently an unsubstituted or substituted monovalent hydrocarbon group of 1 to 12 carbon atoms that does not contain an aliphatic unsaturated bond; r, s, t, and v are independently 0 or a positive number; u is 0 or a positive number of 200 or less; w is 0 or a positive number of 10 or less; x is 0 or a positive number of 10 or less; s, u, and w are not simultaneously 0; and 3≦s+u+w≦200.

9. An organopolysiloxane composition for release sheets according to claim 1 or 4, wherein the total content of cyclooctamethyltetrasiloxane, cyclodecamethylpentasiloxane, and cyclododecamethylhexasiloxane is 1,000 ppm (mass) or less in component (A) or the sum of components (A) and (E).

10. The organopolysiloxane composition for release sheets according to any one of claims 1 to 8, wherein the release force when TESA-7475 tape is peeled from a release sheet that is a cured product of the organopolysiloxane for release sheets at a peel rate of 150 m / min according to FINAT Test Method No. 4 is less than 2.5 times the peel force when TESA-7475 tape is peeled at a peel rate of 0.3 m / min according to FINAT Test Method No.

3.

11. The organopolysiloxane composition for release sheets according to any one of claims 1 to 8, wherein the release force when TESA-7475 tape is peeled from a release sheet that is a cured product of the organopolysiloxane for release sheets at a peel rate of 150 m / min according to FINAT Test Method No. 4 is greater than 1.2 and less than 2.5, relative to the release force when TESA-7475 tape is peeled at a peel rate of 0.3 m / min according to FINAT Test Method No. 3.

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