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CN-122029250-A - Curable organopolysiloxane composition for release sheet and release sheet

CN122029250ACN 122029250 ACN122029250 ACN 122029250ACN-122029250-A

Abstract

A curable organopolysiloxane composition comprising the following components (A), (B), (C) and (D) and having no separation or precipitation of an addition reaction controlling agent even when stored at low temperatures, and having excellent low-temperature storage stability and excellent pot life at high temperatures. An organopolysiloxane having an alkenyl group bonded to silicon, (B) an organohydrogen polysiloxane, (C) an addition reaction controlling agent comprising (C-1) and (C-2) 0.06 to 0.60 parts by mass per 100 parts by mass of the total of the components (A) and (B), and the mass ratio (C-2)/(C-1) of (C-2) to (C-1) is 0.10 to 5.00, (C-1) an acetylenic alcohol having a boiling point of 150 to 189 ℃, and (C-2) a compound having a refractive index of 1.420 to 1.450 at 25 ℃ and a boiling point of 190 ℃ or more, and (D) a platinum group metal catalyst.

Inventors

  • XIAO LINZHONG
  • IHARA TOSHIAKI

Assignees

  • 信越化学工业株式会社

Dates

Publication Date
20260512
Application Date
20241001
Priority Date
20231013

Claims (14)

  1. 1. A curable organopolysiloxane composition for release sheets comprising the following components (A), (B), (C) and (D), (A) Having at least 2 silicon-bonded alkenyl groups in 1 molecule, a silicon-bonded alkenyl group content of 0.001 to 0.3mol/100g, a viscosity of 1 to 10000 Pa at 25 DEG C S is 90 to less than 100 parts by mass of organopolysiloxane, (B) Having at least 3 silicon-bonded hydrogen atoms in 1 molecule, a content of silicon-bonded hydrogen atoms of 0.5 to 2.0mol/100g, and a viscosity of 2 to 200mPa at 25 DEG C S is an organohydrogen polysiloxane in an amount such that the ratio of the number of silicon-bonded hydrogen atoms in the component (B) to the number of alkenyl groups in the component (A) is 0.5 to 5.0 times, (C) Comprises (C-1) and (C-2) in an amount of 0.06 to 0.60 parts by mass per 100 parts by mass of the total of the components (A) and (B) and (C-2)/(C-1) of 0.10 to 5.00, An acetylenic alcohol having a boiling point of 150 to 189 ℃ and represented by the following formula (1) in an amount of 0.02 to 0.40 parts by mass based on 100 parts by mass of the total of the components (A) and (B), [ Chemical 1] Wherein R is independently a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond, 2R may be bonded to each other to form a ring, (C-2) a compound having a refractive index of 1.420 to 1.450 at 25 ℃ and a boiling point of 190 ℃ or more, in an amount of 0.02 to 0.40 parts by mass based on 100 parts by mass of the total of the components (A) and (B), (D) The platinum group metal catalyst is 0.1 to 200ppm in terms of platinum group metal relative to the total mass of the components (A) - (C).
  2. 2. The curable organopolysiloxane composition for release sheets according to claim 1, which is a 2-liquid type curable organopolysiloxane composition for release sheets comprising a 2-1 nd liquid composition and a 2-2 nd liquid composition, wherein the 2-1 nd liquid composition comprises a (a) component and a (D) component, and the 2-2 nd liquid composition comprises a (B) component and a (C) component, optionally comprising a (a) component.
  3. 3. The curable organopolysiloxane composition for release sheets according to claim 1, which is a curable organopolysiloxane composition for release sheets for 3-liquid comprising a 3-1 rd liquid composition, a 3-2 rd liquid composition, and a 3-3 rd liquid composition, wherein (I) the 3-1 rd liquid composition consists of only (a) component, the 3-2 rd liquid composition comprises (B) component, (C) component, and optionally (a) component, the 3-3 rd liquid composition comprises (D) component and optionally (a) component, or (II) the 3-1 rd liquid composition comprises (a) component and (C) component, the 3-2 rd liquid composition comprises (B) component and optionally (a) component, and the 3-3 rd liquid composition comprises (D) component and optionally (a) component.
  4. 4. The curable organopolysiloxane composition for release sheets according to claim 1, wherein the (C-1) component is selected from the group consisting of 1-ethynyl-1-cyclohexanol and 3, 5-dimethyl-1-hexyn-3-ol.
  5. 5. The curable organopolysiloxane composition for release sheets according to claim 1, wherein the (C-2) component is 1 or more compounds selected from the group consisting of bis (1, 1-dimethyl-2-propynyloxy) dimethylsilane, 1,3,5, 7-tetramethyl-1, 3,5, 7-tetravinyl siloxane, and 3-methyl-1-dodecyn-3-ol.
  6. 6. The curable organopolysiloxane composition for release sheets according to claim 1, wherein component (a) has at least two silicon-bonded alkenyl groups in 1 molecule, a content of silicon-bonded alkenyl groups of 0.01 to 0.08mol/100g, and a viscosity of 60 to 1000mpa at 25 ℃ S, and a silicone compound.
  7. 7. The curable organopolysiloxane composition for release sheets according to claim 1, wherein component (A) is a mixture comprising the following components (A-1) and (A-2), the content of alkenyl groups bonded to silicon as a whole of component (A) is 0.001 to 0.3mol/100g, (A-1) 50 to 99.9 parts by mass of an organopolysiloxane having in 1 molecule 2 or more alkenyl groups bonded to silicon atoms, the content of alkenyl groups bonded to silicon being 0.001mol/100g or more and less than 0.3mol/100g, 0.1 To 50 parts by mass of an organopolysiloxane having 0.1 to 20 silicon atom-bonded (meth) acryloyl group-containing groups in 1 molecule and 0.1 or more silicon atom-bonded alkenyl groups in 1 molecule.
  8. 8. The curable organopolysiloxane composition for release sheets according to claim 7, wherein component (A-1) is an organopolysiloxane represented by the following formula (2), （R 1 3 SiO 1/2 ） a （R 1 2 SiO） b （R 1 SiO 3/2 ） c （SiO 4/2 ） d （2） Wherein R 1 is a hydroxyl group, an alkenyl group having 2 to 12 carbon atoms, or an unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond, at least two of R 1 are alkenyl groups, and a to d are each 0 or positive numbers satisfying 2≤a≤202, 5≤b≤1000, 0≤c≤100, and 0≤d≤100, but 0≤c+d≤100.
  9. 9. The curable organopolysiloxane composition for release sheets according to claim 7, wherein component (A-2) is an organopolysiloxane represented by the following formula (3), （R 2 3 SiO 1/2 ） e （R 2 2 SiO） f （R 2 SiO 3/2 ） g （SiO 4/2 ） h （3） Wherein R 2 is a hydroxyl group, an alkenyl group having 2 to 12 carbon atoms or a (meth) acryloyl group-containing group, or an unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond, at least 0.1 of R 2 is an alkenyl group, 0.1 to 20 of R 2 are (meth) acryloyl group-containing groups, and e to h are 0 or positive numbers satisfying 2≤e≤202, 5≤f≤1000, 0≤g≤100, and 0≤h≤100, respectively, but 0≤g+h≤100.
  10. 10. The curable organopolysiloxane composition for release sheets according to claim 1, wherein component (B) is 1 or more kinds of organohydrogen polysiloxanes represented by the following formula (4), R 3 i H j SiO (4-i-j)/2 (4) Wherein R 3 is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and having no aliphatic unsaturated bond, and i and j are positive numbers satisfying 0.7≤i≤2.1, 0.001≤j≤1.0, and 0.8≤i+j≤3.0.
  11. 11. The curable organopolysiloxane composition for release sheets according to claim 1, wherein component (B) is a linear organopolysiloxane represented by the following formula (5), （R 3 3 SiO 1/2 ） 2 （R 3 HSiO） p （R 3 2 SiO） q （5） Wherein R 3 is as described above, p to q are integers satisfying 3≤p≤199 and 1≤q≤197, respectively, but satisfying 4≤p+q≤200.
  12. 12. The curable organopolysiloxane composition for release sheets according to claim 11, wherein component (B) is a combination of (B-1) a linear organopolysiloxane represented by the formula (5) and (B-2) a linear organopolysiloxane represented by the formula (6) and the mass ratio (B-2)/(B-1) of components (B-2) and (B-1) is 1 to 10, (R 3 3 SiO 1/2 ） 2 （R 3 HSiO） k (6) Wherein R 3 is as described above, and k is an integer satisfying 1≤k≤200.
  13. 13. The curable organopolysiloxane composition for release sheets according to claim 1, which contains no solvent.
  14. 14. A release sheet comprising a sheet-like substrate and a cured film obtained by curing the curable organopolysiloxane composition for release sheet according to any one of claims 1 to 13 on one or both surfaces of the substrate surface.

Description

Curable organopolysiloxane composition for release sheet and release sheet Technical Field The present invention relates to a curable organopolysiloxane composition for release sheets and a release sheet using the same. Background Conventionally, in order to prevent adhesion of a base material such as paper or plastic to an adhesive material, a cured film of an organopolysiloxane composition is formed on the surface of the base material, and release characteristics are imparted thereto. As a method for forming the organopolysiloxane cured film on the substrate surface, a releasable film forming method using an addition reaction is widely used because of its excellent curability. In the method for forming a release film by addition reaction, there are a type in which an organopolysiloxane composition is dissolved in an organic solvent, a type in which an emulsion is prepared by dispersing an emulsifier in water, and a solvent-free type containing only an organopolysiloxane, but the solvent type has a disadvantage that it is sometimes harmful to the human body and the environment, and therefore, from the viewpoint of safety, a switch from the solvent type to the solvent-free type has been made. In addition, since high energy is required for removing water, it is difficult to obtain a cured film under curing conditions of a relatively low temperature and a short time. Therefore, the solvent-free organopolysiloxane composition is used at most. The solvent-free type addition reaction controlling agent is composed of a main component (an alkenyl group-containing siloxane), a crosslinking agent (an SiH group-containing siloxane), and a platinum catalyst as basic components, and is required to inhibit the addition reaction of the platinum catalyst at room temperature and to rapidly perform the addition reaction at high temperature. As the control agent, it has been conventionally known that an acetylenic alcohol may be used, and among the acetylenic alcohols, there is a problem that the compatibility with the organopolysiloxane composition is low, and particularly in the case of blending the control agent in a high concentration in 2 liquid or 3 liquid, separation of the acetylenic alcohol may be a problem. In fact, 1-ethynyl-1-cyclohexanol used in large amounts is poor in compatibility with the organopolysiloxane composition from the standpoint of controllability for addition reaction and easiness of obtaining. Further, since the melting point is about 31 ℃, there is a problem that the solid is likely to be precipitated during storage at a low temperature. Therefore, as a control agent for improving compatibility with an organopolysiloxane composition and storage stability at low temperature, a control agent for silylating a hydroxyl group of an acetylenic alcohol is also known. However, when these control agents are used alone, although compatibility and storage stability at low temperatures can be improved, there are problems that curability and pot life are reduced. Thus, JP-A9-143371 and JP-A8-176448 disclose organopolysiloxane compositions in which 2 kinds of control agents having different boiling points are used in combination. Japanese patent application laid-open No. 9-143371 discloses that the generation of gels during film formation on a coating roll is suppressed by the combination of 2 addition reaction inhibitors having a boiling point of 130 ℃ or less and a boiling point of 170 ℃ or more. On the other hand, JP-A8-176448 describes that excellent curability and stable pot life can be obtained by the combination of 2 acetylene compounds having a boiling point of 150 ℃ or more and a boiling point of less than 150 ℃. In addition, by combining 2 kinds of organohydrogen polysiloxanes having different amounts of SiH groups, both peelability and adhesion of the film to a substrate are achieved. Furthermore, JP-A11-166122 discloses an organopolysiloxane composition in which a small amount of an acetylenic alcohol and a large amount of a silylated acetylenic alcohol are used together as both control agents. It is described that by using these two control agents in combination, an organopolysiloxane composition having excellent peeling properties and excellent stability in which curability is less likely to change with time can be provided. Patent document 2 describes adhesion to various substrates, shows a relationship between the organohydrogen polysiloxane and the adhesion, and does not mention any relationship between the amount of the control agent and the adhesion. Prior art literature Patent literature Patent document 1 Japanese patent laid-open No. 9-143371 Patent document 2 Japanese patent laid-open No. 8-176448 Patent document 3 Japanese patent laid-open No. 11-166122 Disclosure of Invention Problems to be solved by the invention The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a release sheet curable organopolysiloxane composition w