WO2022138349A1 - Curable silicone composition, release coating agent for silicone adhesive and containing said composition, release film, and laminate - Google Patents

Abstract

[Problem] To provide a curable silicone composition for a release agent that can form a release film in which, even when the film is thin, the release force is small from a silicone adhesive, particularly from a silicone adhesive having a low storage modulus at a low temperature. Further, to provide: a release film that has a low release force and that has superior smoothness of an adhesive layer surface after release; a laminate; and a method for producing said laminate. [Solution] A curable silicone composition comprising: (A) a mixture of two or more types of fluoroalkyl group-containing organopolysiloxanes which are not compatible with each other, which each include a fluoroalkyl group and an alkenyl group, and in which the contained amounts of fluoroalkyl groups are different from each other; (B) an organohydrogen polysiloxane; (C) an organopolysiloxane that has a fluorine atom-containing organic group and that does not include a hydrosilylation reaction-causing group; (D) a catalyst for hydrosilylation reaction; and (E) an organic solvent. A use of a release film or the like provided with a cured product of said curable silicone composition.

Description

A curable silicone composition, a release coating agent for a silicone pressure-sensitive adhesive composed of the above composition, a release film, and a laminate.

The present invention uses a curable silicone composition, a release coating agent comprising the composition, particularly a release coating agent for a silicone pressure-sensitive adhesive (pressure-sensitive adhesive) having a low storage elasticity at low temperatures, and a release coating agent thereof. The present invention relates to a release film, particularly a release film for a silicone pressure-sensitive adhesive, and a laminate containing the release film, particularly a laminate containing a release film and a silicone pressure-sensitive adhesive.

Silicone adhesives (pressure-sensitive adhesives) have excellent heat resistance, cold resistance, weather resistance, chemical resistance, electrical insulation, etc., so they have various functionalities such as industrial protective tapes, masking tapes, etc. It has been widely used as an adhesive for tapes and the like. Further, in recent years, it has also been used for so-called assembly applications represented by bonding optical components (display devices, functional films, lenses, etc.) for liquid crystal displays. Since the silicone adhesive strongly adheres to the surface coated with silicone rubber or silicone-based material, it is possible to use the usual silicone-based release agent used for acrylic-based or organic rubber-based adhesives. Instead, various curable silicone release agent compositions for forming a release film capable of easily removing the silicone pressure-sensitive adhesive have been proposed. The composition is coated on a flexible base material such as a plastic film as a release coating agent to form a release film, which is further laminated with a sheet-like or roll-like tape to which the release coating agent is bonded. Used as a body.

For example, Patent Document 1 describes an organoas as a release agent for a silicone pressure-sensitive adhesive, which has at least 300 silicon atoms, 0.5 to 2 mol% of vinyl group-containing siloxane units, and 30 mol% of fluoroalkyl group-containing siloxane units. From polysiloxanes, organohydrogenpolysiloxanes that have at least two silicon atom-bonded hydrogen atoms per molecule and are compatible with the organopolysiloxane, hydrosilylation reaction catalysts, and hydrosilylation reaction inhibitors. A curable coating composition has been proposed.

Further, Patent Document 2 describes a mold release agent composition for a silicone pressure-sensitive adhesive containing two types of fluoroalkyl-modified polydimethylsiloxane having different amounts of alkenyl groups for the purpose of light peeling, and the present invention is formed by applying the same to a substrate. A release sheet has been proposed.

Further, Patent Document 3 describes an organopolysiloxane having an alkenyl group-containing organic group and a fluoroalkyl group, and an organohydrogenpolysiloxane having at least three silicon atom-bonded hydrogen atoms in one molecule for the purpose of adjusting the peeling force. , A catalyst for hydrosilylation reaction, an organic solvent, and a release agent composition for a silicone pressure-sensitive adhesive composed of an organopolysiloxane having an alkenyl group and no fluoroalkyl group, and a release formed by applying the same to a plastic film. A film has been proposed.

Patent Document 4 describes a release sheet containing an organosiloxane release control agent having a fluorine atom-containing organic group and no hydrosilylation-reactive group, a release agent composition containing the same, and a cured layer made of the cured product. Has been proposed.

In Patent Document 5, as an organopolysiloxane having a fluoroalkyl group and at least two alkenyl groups in the molecule, when mixed without a solvent, the mixture is stirred at 25 ° C., left for 24 hours, and then visually observed. A curable silicone composition comprising a curable silicone composition comprising a combination of two or more organopolysiloxanes that are completely incompatible or completely incompatible, which are cured. There have been proposed a release sheet including a release layer made of a cured product obtained from the above, and a laminate composed of a structural unit in which a silicone pressure-sensitive adhesive layer is laminated on the release layer.

However, these documents do not describe or suggest any combination of a particular exfoliation control agent with a particular curable silicone composition. In particular, in the technical relationship with the silicone pressure-sensitive adhesive having a low storage elastic modulus at low temperature, it is not described or suggested that it exerts a remarkable effect in each step and its industrial significance.

Japanese Unexamined Patent Publication No. 2-245031 Japanese Unexamined Patent Publication No. 2005-60554 Japanese Unexamined Patent Publication No. 2016-182391 Japanese Patent Publication No. WO2016-006252 Special WO2020-138413 Gazette

The inventors have discovered new technical challenges. That is, when the release film is peeled off from the peelable laminate containing the silicone pressure-sensitive adhesive (also referred to as "pressure-sensitive adhesive", the same applies hereinafter), the work efficiency is improved and the peeled silicone pressure-sensitive adhesive is used. A lower and more stable peeling force is required to prevent surface roughness and the like. However, in recent years, there has been an increase in demand for silicone-based optical transparent pressure-sensitive adhesives (OCA) for bonding and constructing display devices such as flexible displays / touch panels. At 20 ° C., etc.), a pressure-sensitive adhesive layer having sufficient viscoelasticity and a low storage elastic modulus is required.

However, when a conventionally known composition is used as a peeling coating to form a peeling film and a laminated body, the peeling force between the silicone pressure-sensitive adhesive layer and the peeling layer having a low storage elastic modulus under the above-mentioned low temperature is increased. It cannot be sufficiently reduced, and even if it is peeled off, problems such as roughness and wrinkles appear on the surface of the silicone adhesive after the peeling film is peeled off, resulting in transparency and visibility. May be impaired, or the yield or performance may be adversely affected. If a release agent layer that can be peeled off while maintaining a sufficiently small peeling force and a good and smooth adhesive surface for a silicone adhesive having such new properties can be realized, a silicone adhesive having excellent low temperature characteristics will be manufactured. It can be used more effectively.

That is, an object of the present invention is that even if the peeling layer is a thin layer, it can be peeled from a silicone pressure-sensitive adhesive having a low storage elasticity at a low temperature with a low peeling force, and the silicone pressure-sensitive adhesive can be peeled off. A release film having a stable release force, a release agent for such a release film, and a curable silicone composition that can be used as a release agent, as well as a substrate, a silicone pressure-sensitive adhesive layer, and a release agent layer. Is to provide a laminate comprising. The release film generally has a release layer formed by coating a release agent on a flexible base material such as a plastic film.

The present inventor (A) as an organopolysiloxane having a fluoroalkyl group and at least two alkenyl groups in the molecule, is visually observed after stirring at 25 ° C. and leaving for 24 hours when mixed without a solvent. Organo having two or more organopolysiloxanes that are not completely incompatible or completely incompatible with each other, and (C) a fluorine atom-containing organic group and no hydrosilylation-reactive group. The present invention has been completed by discovering that the above-mentioned problems can be solved by a hydrosilylation reaction-curable silicone composition using a combination of polysiloxanes.

That is, the curable silicone composition according to the present invention is hydrosilylation reaction curable, uses a mixture of an organopolysiloxane having a specific fluorine-containing organic group and an alkenyl group as a main agent, and further contributes to the hydrosilylation reaction. It is characterized by the addition of an organopolysiloxane having a fluorine-containing organic group that does not. Further, a release coating agent, a release film, and a laminate, in which the release layer obtained by curing the curable silicone composition is used as a release layer for a silicone pressure-sensitive adhesive, particularly a silicone pressure-sensitive adhesive having a low storage elastic modulus at a low temperature. Characterized by the body.

Specifically, the curable silicone composition of the present invention is
(A) A mixture of two or more kinds of fluoroalkyl group-containing organopolysiloxanes having a fluoroalkyl group and at least two alkenyl groups in one molecule and having different fluoroalkyl group contents from each other. More than one kind of fluoroalkyl group-containing organopolysiloxane is a combination of those that are not completely compatible at 25 ° C. when mixed without solvent.
(B) Organohydrogenpolysiloxane having at least three silicon atom-bonded hydrogen atoms in one molecule,
(C) Organopolysiloxane having a fluorine atom-containing organic group and no hydrosilylation-reactive group.
It contains (D) a catalyst for hydrosilylation reaction and (E) an organic solvent.

Further, the above-mentioned problems are a release coating agent, a release film, and a release film in which the release layer obtained by curing the curable silicone composition is used as a release layer for a silicone pressure-sensitive adhesive having a storage elastic modulus of 5 MPa or less at −20 ° C. It can be solved by the laminate.

By using the curable silicone composition of the present invention as a release coating agent, a silicone pressure-sensitive adhesive that adheres to the release layer even if the thickness of the release layer is thin, particularly a silicone pressure-sensitive adhesive having a low storage elastic modulus at low temperatures. It is possible to form a release film that can be released from the release layer with a low release force. Further, in the release film and the laminate of the present invention, the silicone pressure-sensitive adhesive disposed on the release layer (the pressure-sensitive adhesive formed by the curing reaction on the release layer, and the release layer attached to the already-formed pressure-sensitive adhesive). (Including both) can be stably peeled off from the peeling layer with low peeling force, and the surface of the silicone adhesive after peeling can maintain a uniform adhesive surface with less roughness and wrinkles. It can be suitably used as a display device or a member of an electronic material that requires uniformity.

In particular, by utilizing a release layer obtained by curing the curable silicone composition of the present invention, the storage elastic modulus at −20 ° C., which was difficult to handle and produce a releaseable laminate with a conventional release agent, was increased. For silicone pressure-sensitive adhesives of 5 MPa or less, especially sheet-like / film-like pressure-sensitive adhesives, a peelable film and a peelable laminate exhibiting low peeling power and good peeling characteristics can be provided, so that good viscoelasticity at low temperature can be obtained. It enables the provided silicone adhesive and its industrial range of use to be expanded.

First, the curable silicone composition of the present invention will be described in detail.

[Curable Silicone Composition]
The curable silicone composition of the present invention is
(A) A mixture of two or more kinds of fluoroalkyl group-containing organopolysiloxanes having a fluoroalkyl group and at least two alkenyl groups in one molecule and having different fluoroalkyl group contents from each other. More than one kind of fluoroalkyl group-containing organopolysiloxane is a combination of those that are not completely compatible at 25 ° C. when mixed without solvent.
(B) Organohydrogenpolysiloxane having at least three silicon atom-bonded hydrogen atoms in one molecule,
(C) Organopolysiloxane having a fluorine atom-containing organic group and no hydrosilylation-reactive group.
It contains (D) a catalyst for hydrosilylation reaction, and (E) an organic solvent, and may optionally contain (F) a hydrosilylation reaction control agent and other optional components. Hereinafter, these essential components and other components will be described.

[(A) component]
The component (A) is a mixture of two or more kinds of fluoroalkyl group-containing organopolysiloxanes having a fluoroalkyl group and at least two alkenyl groups in one molecule and having different fluoroalkyl group contents from each other. Further, the two or more kinds of fluoroalkyl group-containing organopolysiloxanes need to be a combination of those that are not completely compatible at 25 ° C. when they are mixed without a solvent. The meaning of "not completely incompatible at 25 ° C. when mixed without solvent" means that a mixture of two or more fluoroalkyl group-containing organopolysiloxanes is placed in a clear glass vial with a lid and 25. It means that the mixture becomes cloudy or separates into two phases immediately after sufficient stirring at ° C. and when visually observed 24 hours later, and does not exhibit a uniform and transparent liquid state. When the fluoroalkyl group-containing organopolysiloxane is not a liquid such as gum or paste at 25 ° C, the mixture is heated to a temperature at which it becomes liquid, sufficiently stirred, and then immediately cooled to 25 ° C and immediately after cooling to 25 ° C. It means that the mixture is cloudy or separated into two phases when visually observed after 24 hours, and does not exhibit a uniform and transparent liquid state. The mixture in which these components are used in combination has a peeling force lower than the peeling force with respect to the silicone adhesive estimated by additive averaging based on the result when each component is used alone, and will be described later (described later). When used in combination with the component C), the peeling force between the silicone pressure-sensitive adhesive layer having a low storage elastic modulus and the peeling layer can be sufficiently reduced at low temperatures, and the surface of the silicone pressure-sensitive adhesive after peeling can be sufficiently reduced. A uniform adhesive surface with less roughness and wrinkles can be maintained.

Specifically, the component (A) has the following average composition formula (I):
(R ¹ ₃ SiO _1/2 ) _a (R ¹ ₂ SiO _2/2 ) _b (R ¹ SiO _3/2 ) _c (SiO _4/2 ) _d (I)
(In the formula, R ¹ is the same or different, and independently, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms. , Or a fluoroalkyl group having 1 to 12 carbon atoms, at least two R ^1s in one molecule being the alkenyl group, and at least one R ¹ in one molecule is a fluoroalkyl group having 1 to 12 carbon atoms. Group, where a is positive, b is positive, c is 0 or positive, and d is 0 or positive)
It is preferably an organopolysiloxane represented by.
In the formula (I), R ¹ may be a small amount of a hydroxyl group or an alkoxy group as long as the object of the present invention is not impaired.

In the formula (I), the methyl group is preferable as the alkyl group having 1 to 12 carbon atoms that can be represented by R ¹ .

In the formula (I), the alkenyl group having 2 to 12 carbon atoms that can be represented by R ¹ is preferably a vinyl group or a hexenyl group independently, and a vinyl group is particularly preferable. In the formula (I), at least two R ^1s are alkenyl groups, and the vinyl group-equivalent content of the alkenyl groups is not particularly limited as long as it can be used to form a curable composition. 2.0% by mass or less is preferable, 1.0% by mass or less is more preferable, and 0.5% by mass or less is further preferable. This is because when the content of the alkenyl group becomes larger than necessary, when the curable silicone composition of the present invention is used as a release coating agent to form a release layer for a silicone pressure-sensitive adhesive, the release layer from the silicone pressure-sensitive adhesive layer is formed. This is because the peeling force may be high. The vinyl group-equivalent content of the alkenyl group means the content calculated by replacing the alkenyl group other than the vinyl group with the mass of the equimolar vinyl group.

In the formula (I), examples of the aryl group having 6 to 12 carbon atoms that R ¹ can represent include a phenyl group, a tolyl group, and a xylyl group, and a phenyl group is preferable.

In the formula (I), a benzyl group and a phenylethyl group are exemplified as the aralkyl group having 7 to 12 carbon atoms that can be represented by R ¹ .

In formula (I), as an example of the fluoroalkyl group having 1 to 12 carbon atoms that R ¹ can represent, the 3,3,3-trifluoropropyl group, 3,3,4,4,4-pentafluorobutyl group, 3,3,4,4,5,5,5-heptafluoropentyl group 3,3,4,4,5,5,6,6,6-nonafluorohexyl group 3,3,4,4, 5,5,6,6,7,7,7-Undecafluoroheptyl group 3,3,4,4,5,5,6,6,7,7,8,8,8-Tridecafluorooctyl Groups and 3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-pentadecafluorononyl groups are exemplified, 3,3,4,4, 5,5,6,6,6-nonafluorohexyl groups are preferred.

Regarding a to d in the above formula (I), a is 2 or more, preferably an integer of 2 to 6, b is 1 or more, preferably an integer of 1 to 5,000, and more preferably 30 to 4,000. It is an integer, where c is 0 or a positive number and d is 0 or a positive number. Regarding the component (A), if the degree of siloxane polymerization is less than the lower limit of the above range, it becomes difficult to form a release layer when the curable silicone composition obtained by using the component is used as a release coating agent. If the degree of siloxane polymerization exceeds the upper limit of the above range, the coatability (particularly, thin film coatability) of the obtained curable silicone composition may deteriorate.

The two or more kinds of fluoroalkyl group-containing organopolysiloxanes constituting the component (A) are preferably a mixture of two or more kinds of organopolysiloxanes represented by the above formula (I), and further, the component ( A) is particularly preferably a mixture of the following components (A1) and (A2).

(A1) One or more linear or branched components containing a fluoroalkyl group-containing organodisiloxane unit and having a fluorine atom content of 40% by mass or more, preferably 41% by mass or more, and more preferably 42% by mass or more. One type containing a chain organopolysiloxane and (A2) fluoroalkyl group-containing organodisiloxane unit, and having a fluorine atom content of less than 40% by mass, preferably 39% by mass or less, and more preferably 38% by mass or less. The above linear or branched organopolysiloxane.

That is, the component (A1) is, in the above formula (I), at least ^one of the two R1 units represented by " ^R1 ₂ SiO _2/2 ", preferably one of which is fluoro with 1 to 12 carbon atoms. An alkyl group, particularly preferably a 3,3,4,4,5,5,6,6,6-nonafluorohexyl group, and the mass of a fluorine atom in the total mass of the compound represented by the formula (I). It is a linear or branched organopolysiloxane having a proportion of 40% by mass or more, preferably 41% by mass or more, and more preferably 42% by mass or more.

Further, in the above formula (I), the component (A2) is at least ^one of the _two ^R1 units represented by "R12 SiO _2/2 ", preferably one of which is fluoro with 1 to 12 carbon atoms. An alkyl group, particularly preferably a 3,3,4,4,5,5,6,6,6-nonafluorohexyl group, and the mass of a fluorine atom in the total mass of the compound represented by the formula (I). It is a linear or branched organopolysiloxane having a proportion of less than 40% by mass, preferably 39% by mass or less, more preferably 38% by mass or less.

Therefore, the (A1) component and the (A2) component have different fluorine atom contents. The difference between the fluorine atom content of the component (A1) and the fluorine atom content of the component (A2) is preferably a value larger than 3% by mass, and preferably 4% by mass or more. This is because the difference between the fluorine atom contents of the component (A1) and the component (A2) is the above-mentioned value, so that both components tend to be incompatible with each other.

Further, in one aspect of the present invention, the component (A1) comprises a fluoroalkyl group-containing organodisiloxane unit after satisfying the above-mentioned conditions for the content of the fluorine atom of the component (A1) and the component (A2). One or more kinds containing, and the fluoroalkyl group is 3,3,4,4,5,5,6,6,6-nonafluorohexyl group, and the unit is 39 mol% or more of the total organosiloxane unit. It is a linear or branched organopolysiloxane, the component (A2) contains a fluoroalkyl group-containing organodisiloxane unit, and the fluoroalkyl group is 3,3,4,4,5,5,6,6. It is preferably one or more linear or branched organopolysiloxanes that are 6-nonafluorohexyl groups and the unit is 36 mol% or less of the total organosiloxane unit.

Specific examples of the component (A1) and the component (A2) include, but are not limited to, the fluoroalkyl group-containing organopolysiloxanes listed below. In the following formula, Me, Vi, Hex, Fa1, Fa2, and Fa3 are methyl group, vinyl group, n-hexenyl group, 3,3,4,4,5,5,6,6,6-nona, respectively. Represents a fluorohexyl group, a 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl group, and a 3,3,3-trifluoropropyl group.
Average composition formula:
(Me ₂ ViSiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₇₅₀ (Me (Fa1) SiO _2/2 ) ₇₅₀ (MeViSiO _2/2 ) ₂₀
Organopolysiloxane, represented by
Average composition formula:
(Me ₃ SiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₄₅₀ (Me (Fa1) SiO _2/2 ) ₃₅₀ (MeViSiO _2/2 ) ₁₀
Organopolysiloxane, represented by
Average composition formula:
(Me ₂ (Fa1) SiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₄₅₀ (Me (Fa1) SiO _2/2 ) ₃₅₀ (MeViSiO _2/2 ) ₁₀
Organopolysiloxane, represented by
Average composition formula:
(Me ₂ HexSiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₁₀₀₀ (Me (Fa1) SiO _2/2 ) ₁₀₀₀ (MeHexSiO _2/2 ) ₂₀
Organopolysiloxane, represented by
Average composition formula:
(Me ₂ ViSiO _1/2 ) ₄ (Me ₂ SiO _2/2 ) ₅₀₀ (Me (Fa1) SiO _2/2 ) ₅₀₀ (SiO _4/2 ) ₁
Organopolysiloxane, represented by
Average composition formula:
(Me ₂ ViSiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₅₀₀ (Me (Fa2) SiO _2/2 ) ₅₀₀ MeViSiO _2/2 ) ₁₀
Organopolysiloxane, represented by
Average composition formula:
(Me ₂ ViSiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₁₄₇₀ (Me (Fa1) SiO _2/2 ) ₁₁₀₀ (MeViSiO _2/2 ) ₈
Organopolysiloxane, represented by
Average composition formula:
(Me ₂ ViSiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₁₂₈₀ (Me (Fa1) SiO _2/2 ) ₁₂₇₀ (MeViSiO _2/2 ) ₇
Organopolysiloxane, represented by
Average composition formula:
(Me ₂ ViSiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₉₀₀ (Me (Fa1) SiO _2/2 ) ₄₅₀ (MeViSiO _2/2 ) ₁₀
Organopolysiloxane, represented by
Average composition formula:
(Me ₂ ViSiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₁₁₀₀ (Me (Fa1) SiO _2/2 ) ₄₀₀ (MeViSiO _2/2 ) ₇
Organopolysiloxane, represented by
Average composition formula:
(Me ₂ ViSiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₁₁₀₀ (Me (Fa1) SiO _2/2 ) ₄₀₀ (Me (Fa3) SiO _2/2 ) ₁₀₀ (MeViSiO _2/2 ) ₁₀
Organopolysiloxane represented by.

In the curable silicone composition of the present invention, the mass ratio of the component (A1) to the component (A2) contained in the composition is 1/99 to 99/1 ((A1) / (A2)). Preferably, 10/90 to 90/10 is more preferable, 20/80 to 80/20 is more preferable, and 30/70 to 70/30 is most preferable. When the component (A1) and the component (A2) are used in combination, the silicone adhesion estimated by the arithmetic mean based on the result when the component (A1) or the component (A2) is used alone instead of the component (A). A peeling force lower than the peeling force against the agent can be obtained.

[(B) component]
The component (B) is an organopolysiloxane having at least three silicon atom-bonded hydrogen atoms (Si—H) in one molecule, and an addition reaction with the component (A) by a hydrosilylation reaction is carried out to carry out the addition reaction of the present invention. A component that cures the composition. In particular, the component (B) may have a certain amount of a fluorine-containing organic selected from a fluoroalkyl group having 1 to 12 carbon atoms and a fluoro (poly) ether-containing organic group, and has the technical effect of the present invention. It is preferable from the viewpoint of.

As the group other than the hydrogen atom bonded to the silicon atom in the component (B), an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and a group having 1 to 12 carbon atoms. Twelve fluoroalkyl groups and fluoro (poly) ether-containing organic groups having 2 to 100 carbon atoms are exemplified. A small amount of hydroxyl group or alkoxy group may be bonded to the silicon atom in the component (B) as long as the object of the present invention is not impaired.

The molecular structure of the component (B) is not limited, and examples thereof include linear, branched chain, linear with partial branch, resinous, and cyclic, preferably linear or linear with partial branch. It is a shape.

As such a component (B), the following average composition formula (II):
(R ² ₃ SiO _1/2 ) _aa (R ² ₂ SiO _2/2 ) _ab (R ² SiO _3/2 ) _ac (SiO _4/2 ) _ad (II)
Organopolysiloxane represented by is exemplified.

In formula (II), R ² is the same or different, and independently has a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and 1 carbon atom. -12 Fluoroalkyl groups or fluoro (poly) ether-containing organic groups, provided that at least 3 of R ² are hydrogen atoms. Further, aa is a positive number, ab is a positive number, ac is 0 or a positive number, and ad is 0 or a positive number. However, when aa is 2, the total of aa to ad is preferably in the range of 5 to 200, the lower limit thereof is 10 or 15, while the upper limit thereof is 150, 120, 100, Within any combination of upper and lower limits, such as 80, 70, 60, 50, or 40. This is because, when aa is 2, if the total of aa to ad is not less than the lower limit of the above range, the cross-linking of the present composition proceeds sufficiently, while it is not more than the upper limit of the above range. This is because the handling workability of this composition is good.

Examples of the alkyl group having 1 to 12 carbon atoms that ^R2 can represent include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and an undecyl group. Dodecyl groups are exemplified, and methyl groups are preferred.

Examples of the aryl group having 6 to 12 carbon atoms that ^R2 can represent include a phenyl group, a tolyl group, and a xsilyl group, and a phenyl group is preferable.

Further, examples of the aralkyl group having 7 to 12 carbon atoms that ^R2 can represent include a benzyl group and a phenylethyl group.

Further, as the fluoroalkyl group having 1 to 12 carbon atoms which can be represented by R ² , 3,3,3-trifluoropropyl group, 3,3,4,4,4-pentafluorobutyl group and 3,3,4 , 4,5,5,5-heptafluoropentyl group, 3,3,4,4,5,5,6,6,6-nonafluorohexyl group, 3,3,4,4,5,5,6 , 6,7,7,7-Undecafluoroheptyl group, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl group, and 3, 3,4,4,5,5,6,6,7,7,8,8,9,9,9-pentadecafluorononyl group is exemplified and 3,3,4,4,5,5,5 -Heptafluoropentyl group, 3,3,4,4,5,5,6,6,6-nonafluorohexyl group, 3,3,4,4,5,5,6,6,7,7,7 -A group selected from an undecafluoroheptyl group and a 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl group is preferable, and 3,3 , 4,4,5,5,6,6,6-nonafluorohexyl groups are particularly preferred.

Further, as the fluoro (poly) ether-containing organic group that can be represented by R ² , the fluoro (poly) ether-containing organic group exemplified in R ¹ is preferably used.

The component (B) of the present invention may or may not have a group selected from a fluoroalkyl group and a fluoro (poly) ether-containing organic group. When the composition of the present invention is cured using the composition of the present invention as a coating agent by combining with the above-mentioned component (A) without using an organohydrogenpolysiloxane having a fluorine atom-containing group as the component (B), A release layer having excellent release property, particularly excellent release property against a silicone pressure-sensitive adhesive, can be obtained, but from the viewpoint of the technical effect of the present invention, it is particularly preferable to have a certain amount of these fluorine atom-containing groups. The component (B) is represented by the above average composition formula (II), and ^R2 is a hydrogen atom, an alkyl group (particularly a methyl group), and a fluoroalkyl group and / or a fluoro (poly) ether-containing organic group. The combination organopolyhydrogennesiloxane is particularly preferred.

When the component (B) of the present invention has a group selected from the group consisting of a fluoroalkyl group and a fluoro (poly) ether-containing organic group, the fluoroalkyl group and / or the fluoro (poly) ether-containing organic group in the molecule is used. The content of the derived fluorine atom is not particularly limited, but is preferably at least 20% by mass, at least 25% by mass, at least 30% by mass, or at least 35% by mass. Further, the upper limit of the content of the fluorine atom in the component (B) is preferably 60% by mass at most, or 50% by mass at most.

Specific examples of the component (B) include, but are not limited to, the organopolysiloxanes listed below. In the following formulas, Me, F2a and F1b are methyl groups, 3,3,4,4,5,5,6,6-nonafluorohexyl groups, respectively, and the following formulas:
F [CF (CF ₃ ) CF ₂ O] ₂ CF (CF ₃ ) CH ₂ O- (CH ₂ ) _3-
Represents the group indicated by.
Average composition formula:
(Me ₃ SiO _1/2 ) ₂ (Me (F2aSiO _2/2 ) ₁₂ (MeHSiO _2/2 ) ₂₇
Organopolysiloxane, represented by
Average composition formula:
(Me ₃ SiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₅₅ (Me (F1bSiO _2/2 ) ₂₅ (MeHSiO _2/2 ) ₂₅
Organopolysiloxane, represented by
Average composition formula:
(Me ₃ SiO _1/2 ) ₂ (MeHSiO _2/2 ) ₅₀
Organopolysiloxane, represented by
Average composition formula:
(Me ₃ SiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₃₀ (MeHSiO _2/2 ) ₃₀
Organopolysiloxane, represented by
Average composition formula:
(Me ₂ HSiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₃₀ (MeHSiO _2/2 ) ₃₀
Organopolysiloxane represented by.
One or a combination of two or more selected from these can be used as the component (B).

The content of the component (B) in the curable silicone composition of the present invention is such that the molar ratio of the silicon atom-bonded hydrogen atom to the alkenyl group in the component (A) is 0.1 to 20 (silicon atom-bonded hydrogen atom / alkenyl). The amount is within the range of (base), preferably the lower limit is 0.5, 0.8, or 1, while the upper limit is 18, 17, 16, 15, 14, 13, or 12. It is within the range of any combination of upper and lower limits. This is because when the content of the component (B) is not less than the lower limit of the above range, the crosslinking of the present curable silicone composition proceeds sufficiently, while when it is not more than the upper limit of the above range, it is obtained. This is because the characteristics of the peelable film can be stabilized.

[(C) component]
The component (C) is an organopolysiloxane having a fluorine atom-containing organic group in the molecule and no hydrosilylation-reactive group, and has excellent peelability in a film obtained by curing a silicone release agent composition. It is a peeling control agent component for imparting. The curable silicone composition according to the present invention and the release agent layer obtained by the effect thereof have not only low release characteristics but also conventional release agents by using the above-mentioned component (A) and component (C) in combination. Achieves a sufficiently low peeling force for silicone adhesives that could not achieve sufficient peeling characteristics, especially silicone adhesives with a low storage elastic modulus at low temperatures, and a uniform surface of the adhesive after peeling. Allows you to maintain.

The molecular structure of the component (C) is not limited, and examples thereof include linear, branched chain, linear with partial branch, resinous, and cyclic, preferably linear or linear with partial branch. It is a shape.
As such a component (C), the following average composition formula (III):
(R ³ ₃ SiO _1/2 ) _ba (R ³ ₂ SiO _2/2 ) _bb (R ³ SiO _3/2 ) _bc (SiO _4/2 ) _bd (III)
It is desirable that it is an organopolysiloxane represented by.

In formula (III), R ³ is the same or different, and independently has an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and 1 to 12 carbon atoms. It is a fluoroalkyl group or a fluoro (poly) ether-containing organic group. Further, ba is a positive number, bb is a positive number, bc is 0 or a positive number, and bd is 0 or a positive number. However, when ba is 2, the total of ba to bd is preferably in the range of 1 to 5,000, and more preferably an integer of 30 to 3,000.

As the alkyl group having 1 to 12 carbon atoms that can be represented by R ³ , a methyl group is preferable.

Further, as the aryl group having 6 to 12 carbon atoms that can be represented by R ³ , a phenyl group is preferable.

Further, examples of the aralkyl group having ⁷ to 12 carbon atoms that R3 can represent include a benzyl group and a phenylethyl group.

Further, as the fluoroalkyl group having 1 to 12 carbon atoms that can be represented by R ³ , the fluoroalkyl group having 1 to 12 carbon atoms exemplified in R ² is preferably used.

Further, as the fluoro (poly) ether-containing organic group that can be represented by R ³ , the fluoro (poly) ether-containing organic group exemplified in R ¹ is preferably used.

The content of the fluorine atom due to the fluorine atom-containing organic group in the component (C) is preferably 20 to 40% by mass, more preferably 23 to 35% by mass, and 27 to 34% by mass. It is particularly preferable to have. On the other hand, if the content of the fluorine atom-containing organic group in one molecule is less than the lower limit or exceeds the upper limit, excellent peelability may not be obtained.

The organopolysiloxane is characterized in that it does not contain a hydrosilylation-reactive group in the molecule in addition to the content of a fluorine atom-containing organic group. When the organopolysiloxane contains a hydrosilylation-reactive group, particularly in a silicone stripping agent composition that is cured by the hydrosilylation reaction, the organopolysiloxane is used as a cross-linking agent or a main agent in the silicone cured product having a stripping property. It becomes easy to form a covalent bond, and as a peeling control agent, excellent peeling property may not be realized.

Further, the molecular chain end of the organopolysiloxane is preferably a trimethylsiloxy group or a silanol group, and more preferably one or more of the molecular chain ends is a trimethylsilyl group.

Specifically, such an organopolysiloxane includes a polymer chain double-ended trimethylsiloxy group-blocking methyl (3,3,3-trifluoropropyl) polysiloxane and a molecular chain double-ended trimethylsiloxy blocking methyl (3,3,3-). Trifluoropropyl) siloxane / dimethylsiloxane copolymer, molecular chain double-ended trimethylsiloxy-blocking methyl (3,3,4,4,5,5,6,6,6-nonafluorohexyl) siloxane / dimethylsiloxane copolymer , Molecular chain double-ended trimethylsiloxy group-blocking methyl (3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl) siloxane / dimethylsiloxane copolymer, Methyl (3,3,3-trifluoropropyl) siloxane / dimethylsiloxane copolymer at both ends of the molecular chain, Methyl (3,3,4,4,5,5,6) at both ends of the molecular chain 6,6-Nonafluorohexyl) siloxane / dimethylsiloxane copolymer, molecular chain double-ended silanol group-blocking methyl (3,3,4,4,5,5,6,6,7,7,8,8,8 -Tridecafluorooctyl) siloxane / dimethylsiloxane copolymer, and methyl (3,3,4,5,5) in which one end of the molecular chain is sealed with silanol and the other end is closed with a trimethylsiloxy group. 5,6,6,6-nonafluorohexyl) siloxane / dimethylsiloxane copolymer is exemplified.

The content of the component (C) is in the range of 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the component (A). When the content of the component (C) is less than 0.01 part by mass with respect to 100 parts by mass of the component (A), the light peelability of the film obtained by curing (peeling cured film) to the adhesive substance is remarkable. May decrease. Further, if the content of the component (C) exceeds 20 parts by mass, the strength of the film obtained by curing is significantly lowered, and it may be difficult to obtain the desired release agent composition.

Further, as the component (C) of the present invention, one of these organopolysiloxanes can be used alone or in combination of two or more.

[(D) component]
The component (D) is a catalyst for a hydrosilylation reaction that promotes curing of the present curable silicone composition by a hydrosilylation reaction, and examples thereof include platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts, and platinum-based catalysts are preferable. It is a catalyst. Examples of the platinum-based catalyst include platinum fine powder, platinum black, platinum-supported silica fine powder, platinum-supported activated carbon, platinum chloride acid, an alcohol solution of platinum chloride, an olefin complex of platinum, and an alkenylsiloxane complex of platinum. To.

The content of the component (D) is an amount that promotes the curing of the present curable silicone composition, and specifically, with respect to the present curable silicone composition, a metal atom, preferably a platinum atom in the catalyst. Is an amount in the range of 0.1 to 1,000 ppm in mass units. This is because when the content of the component (D) is not less than the lower limit of the above range, the curing of the obtained curable silicone composition proceeds sufficiently, while when it is not more than the upper limit of the above range, it is obtained. This is because it becomes difficult for the cured product to be colored.

[(E) component]
The component (E) is an arbitrary organic solvent capable of uniformly dissolving the fluorine-containing organopolysiloxane mixture as the component (A) and incompatible with the entire composition. Here, "compatibility" means to give a uniform and transparent liquid without turbidity in appearance at 25 ° C.

Further, by adding an organic solvent, the viscosity of the curable silicone composition can be lowered, and the coating workability and the wettability to the substrate can be improved.

As the component (E), diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diisobutyl ether, di-sec-butyl ether, di-tert-butyl ether, methyl-tert-butyl ether, ethyl-tert-butyl ether, pentane, m- Xylene hexafluoride, methylheptafluoropropyl ether, methyl nonafluorobutyl ether, ethyl nonafluorobutyl ether, and 3-methoxy-1,1,1,2,2,3,4,5,5,6,6 It is preferably one solvent selected from the group consisting of 6-tridecafluorohexane or a mixed solvent consisting of two or more kinds of solvents.

In addition to the organic solvents described above, additional organic solvents may be added, provided that the appearance of the curable silicone composition can be kept transparent and uniform at 25 ° C. from the time the composition is prepared until it is used. You may use it. Such additional organic solvents are not particularly limited, and aromatic hydrocarbon solvents such as toluene and xylene, aliphatic hydrocarbon solvents such as hexane, heptane, octane, isooctane, decane, cyclohexane, methylcyclohexane and isoparaffin, Hydrocarbon solvents such as industrial gasoline (rubber volatile oil, etc.), petroleum benzine, solvent naphtha, etc .; acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, methylisobutylketone, Ketone solvents such as diisobutylketone, acetonylacetone, cyclohexanone; ester solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate; 2-methoxyethyl acetate, 2-ethoxyethyl acetate, propylene glycol Solvents with esters and ether moieties such as monomethyl ether acetate, 2-butoxyethyl acetate; hexamethyldisiloxane, octamethyltrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, tris (trimethylsiloxy) methylsilane, Siloxane-based solvents such as tetrakis (trimethylsiloxy) silane; the above-mentioned m-xylene hexafluoride, methylheptafluoropropyl ether, methylnonafluorobutyl ether, ethylnonafluorobutyl ether, and 3-methoxy-1,1,1,2,2. , 3,4,4,5,5,6,6,6-Fluorine-modified solvent other than tridecafluorohexane, for example, a fluorine-modified aromatic hydrocarbon solvent such as benzotrifluorolide, perfluoro (2-butyltetrachloride). Fluoromodified ether solvent such as, perfluorotributylamine, perfluorotripentylamine and other fluoromodified alkylamine solvent,
And two or more mixed solvents selected from these are exemplified.

The content of the component (E) is an amount required to uniformly dissolve the entire curable silicone composition, and is 10,000 parts by mass or less with respect to 100 parts by mass of the component (A), which is 20. It is preferably in the range of ~ 5,000 parts by mass.

[(F) component]
The present curable silicone composition may contain (F) a hydrosilylation reaction control agent in order to control the cross-linking reaction. As the component (F), 1-ethynylcyclohexane-1-ol, 2-methyl-3-butin-2-ol, 3,5-dimethyl-1-hexin-3-ol, 2-phenyl-3-butin- Alkyne alcohols such as 2-ol; enein compounds such as 3-methyl-3-penten-1-in, 3,5-dimethyl-3-hexene-1-in; 1,3,5,7-tetramethyl-1 , 3,5,7-Tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane and other methylalkenylsiloxane oligomers; dimethylbis (3-methyl) Alkyneoxysilanes such as -1-butin-3-oxy) silanes and methylvinylbis (3-methyl-1-butin-3-oxy) silanes; methyltris (1-methyl-1-phenyl-propinoxy) silanes, Alkyneoxysilanes such as dimethylbis (1-methyl-1-phenyl-propinoxy) silanes, methyltris (1,1-dimethyl-propinoxy) silanes, and dimethylbis (1,1-dimethyl-propinoxy) silanes. Examples thereof include compounds; benzotriazoles; diallyl maleate, diallyl fumarate, and (tris ((1,1-dimethyl-2-propynyl) oxy) oxy) methylsilanes.

Since the content of the component (F) is not limited and gives a sufficient pot life to the present curable silicone composition, when the component (F) is used, the amount thereof is based on 100 parts by mass of the component (A). , 0.01 to 5 parts by mass, preferably 0.05 to 5 parts by mass, or preferably 0.05 to 3 parts by mass.

[Other additives]
To the extent that the object of the present invention can be achieved, the present curable silicone composition contains a photopolymerization initiator, an antioxidant, a reactive diluent, a leveling agent, a filler, an antioxidant, an antifoaming agent, and a pigment. You may use an additive selected from the above.

[Use]
The curable silicone composition of the present invention is preferably used as a release coating agent, and is suitable for use as a release coating agent for silicone pressure-sensitive adhesives. In particular, it is most suitable for use as a release coating agent for silicone pressure-sensitive adhesives having a low storage elastic modulus at low temperatures. Specifically, for a silicone pressure-sensitive adhesive having a storage elastic modulus at −20 ° C. of 5 MPa or less, preferably 2.5 MPa or less, more preferably 1.0 MPa or less, a uniform pressure-sensitive adhesive layer surface with low peeling force after peeling. This greatly expands the industrial applicability of silicone pressure-sensitive adhesive films / sheets, for which sufficient handling workability could not be guaranteed with conventional release agents.

The present invention also relates to a release film containing a substrate, particularly a film-like substrate, and a release layer made of a cured product obtained by curing the release coating agent of the present invention. Such a release film can be produced, for example, by applying the curable silicone composition of the present invention to a film-like substrate and curing the curable silicone composition. The release film of the present invention is particularly suitable for use as a silicone pressure-sensitive adhesive.

As the base material used for the release film, a film-like base material selected from paper, plastic film, glass, metal and the like can be used. When the product having the release layer provided on the substrate is used as the release film, the substrate is preferably a plastic film, more preferably a polyester film. In particular, it is preferable that both the base material and the release layer are light-transmitting.

The thickness of the release layer is preferably 2.0 μm or less, 1.0 μm or less, or 0.5 μm or less, more preferably 0.4 μm or less, and even more preferably 0.3 μm or less. Further, it is preferably 0.05 μm or more, and more preferably 0.1 μm or more. This is because when the film thickness is at least the lower limit of the above range, the peeling force of the obtained peeling layer is sufficiently low, while when it is at least the upper limit of the above range, the light transmittance of the peeling layer is particularly high. Because it is excellent.

[Laminate]
The present invention is at least a laminate including a peeling layer made of a cured product obtained by curing the curable silicone composition of the present invention and a pressure-sensitive adhesive layer arranged opposite to the peeling layer, particularly a structure including a silicone pressure-sensitive adhesive layer. It also affects the body. In this case, the curable silicone composition can also be referred to as a release coating agent. In this case, the meaning of "opposing" means that the release layer and the pressure-sensitive adhesive layer are in direct contact with each other. Therefore, in general, in the present invention, the release layer and the pressure-sensitive adhesive layer are arranged so as to face each other. In the following description, the structure of the laminate of the present invention will be described by taking a silicone pressure-sensitive adhesive as an example of the pressure-sensitive adhesive, but the pressure-sensitive adhesive is not limited to the silicone pressure-sensitive adhesive.

The laminate according to the present invention may be a laminate having any structure as long as it includes a structure in which the above-mentioned release layer and the silicone pressure-sensitive adhesive layer are arranged so as to face each other. An example of a specific laminated body will be described below.

Examples of the structure of the laminated body of the present invention include (a) to (d) shown below. These specific configurations are, for example, the same as those disclosed by the applicant in Patent Documents 6 and 7, and the release layer thereof is cured by curing the curable silicone composition of the present invention. A silicone pressure-sensitive adhesive layer having a storage elasticity at −20 ° C. of 5 MPa or less can be preferably used as the silicone pressure-sensitive adhesive layer instead of the layer.
(A) A composition composed of a first base material / a release layer / a silicone pressure-sensitive adhesive layer / a second base material,
(B) A configuration in which two or more structural units composed of a base material / a release layer / a silicone adhesive layer are continuously stacked.
(C) A composition composed of a first base material / a first peeling layer / a silicone pressure-sensitive adhesive layer / a second peeling layer / a second base material.
(D) A configuration in which two or more structural units composed of a base material / a first release layer / a silicone pressure-sensitive adhesive layer / a second release layer are continuously stacked.
In the configurations (b) and (d), a discontinuous or continuous base material can be used. Generally, in the case of discontinuity, the laminated body is in the form of a sheet, and when the continuous one is used, the substrate is formed. The laminated body is in the form of a roll.

The base material is preferably in the form of a sheet or a film, particularly preferably in the form of a film, and a base material similar to the base material used for the release film can be used.
Further, either a light-transmitting material or a light-impermeable material can be used as the base material, and when a plurality of base materials are used, both may be arbitrarily combined depending on the purpose.

The laminate of the present invention may be in the form of a laminated sheet in which a plurality of sheet-like members, which are a base material / a release layer / a silicone pressure-sensitive adhesive layer, are vertically laminated, and may have a roll-like shape, for example, a suitable cylinder. It may be in the shape of a roll or in the shape of a roll wound around a tubular core.

In the laminated body of the present invention, the first release layer was arranged on one side of both surfaces of the silicone adhesive layer, and the second release layer was arranged on the other side. In the case of the configuration (for example, the configuration (c) or (d) corresponds to), at least one of the first release layer and the second release layer is a cured product obtained by curing the release coating agent of the present invention. It needs to be a peeling layer made of, but here, when peeling the silicone adhesive from the first peeling layer (F1) and when peeling the silicone adhesive from the second peeling layer. The peeling force (F2) of the above is preferably different.

When the difference in peeling force between F1 and F2 is small, the operation of peeling one peeling layer from the silicone adhesive layer (peeling of the first facing surface) and then the operation of peeling the other peeling layer (second facing surface). ), When the first facing surface is peeled off unintentionally, the second facing surface is partially peeled off, the silicone adhesive layer is destroyed, and it becomes difficult to use the adhesive as originally intended. There is.
The peeling force difference is preferably, for example, 10 gf / inch or more, and more preferably 20 gf / inch or more.

Examples of the method for realizing the above-mentioned peeling force difference include a method of selecting a method for forming the facing surface as described below, a method of making the types of the two peeling layers different, and the like.

In the laminated body of the present invention, the thickness of the release layer is preferably 2.0 μm, 1.0 μm, or 0.5 μm or less, more preferably 0.4 μm or less, and 0.3 μm or less, respectively. Is even more preferable. Further, it is preferably 0.05 μm or more, and more preferably 0.1 μm or more. This is because when the film thickness of the release layer is not less than the lower limit of the above range, the peeling force of the release layer from the silicone adhesive is sufficiently low, while when it is not more than the upper limit of the above range. This is because the release layer has particularly excellent light transmission and is economical.

The silicone pressure-sensitive adhesive composition or the curable silicone pressure-sensitive adhesive composition that can be used for the laminate of the present invention is not limited to a specific one, and is arbitrary that matches the intended use of the laminate, for example, the use as an adhesive tape. However, a silicone pressure-sensitive adhesive having a low storage elastic modulus at a low temperature is particularly preferably used.

The curing mechanism of the curable silicone pressure-sensitive adhesive is not particularly limited, and hydrosilylated curable, peroxide-curable, photocurable, etc. are used, but it can be cured at a relatively low temperature and can be used as a substrate or applied. Hydrosilylated curable materials, which can reduce the influence of heat on the material and are economical in terms of simplicity of the process, are preferably used.

Further, it is extremely useful for the release layer according to the present invention to be applied to a silicone pressure-sensitive adhesive having a low storage elastic modulus at a low temperature. In assemble applications, especially OCA applications, high adhesive strength and high flexibility may be required over a wider temperature range, including low temperatures, which results in lower glass transition temperatures of the cured adhesive composition, eg It is preferable to use a silicone pressure-sensitive adhesive which can be designed so that the composition is below room temperature, has a low storage elastic modulus at a low temperature, and has a sufficiently large elongation at break. For example, the silicone pressure-sensitive adhesive composition proposed by the applicant in International Publication No. 2017/188308, International Publication No. 2020/32285, International Publication No. 2020/32286, etc. is cured and stored at −20 ° C. A silicone pressure-sensitive adhesive layer having a ratio of 5 MPa or less, preferably 2.5 MPa or less, more preferably 1.0 MPa or less can be particularly preferably used in the present invention. Here, the release layer according to the present invention is preferably applied to a silicone pressure-sensitive adhesive having a low storage elastic modulus at a low temperature, but is prevented from being applied to a silicone pressure-sensitive adhesive having a high storage elastic modulus at a low temperature. It is possible to maintain a sufficiently reduced peeling force against a silicone pressure-sensitive adhesive and a uniform pressure-sensitive adhesive layer surface after peeling.

The thickness of the silicone pressure-sensitive adhesive layer of the laminate of the present invention is not particularly limited, but is preferably 0.1 to 300 μm, more preferably 0.5 to 200 μm.

Further, in the laminate of the present invention, the silicone pressure-sensitive adhesive layer can be formed on the entire surface formed by the layer, or can be formed only on a part of the surface. The mode in which the silicone pressure-sensitive adhesive layer is formed only on a part of the surface is not particularly limited, but constitutes any shape other than, for example, one or more dots, one or more straight lines or curves, concentric circles, and the like. A silicone adhesive may be applied as described above. The release layer may also be formed on the entire surface formed by the release layer, but the release layer may be formed according to the shape formed by the silicone pressure-sensitive adhesive formed on the silicone pressure-sensitive adhesive layer.

[Manufacturing method of laminated body]
The method for producing the above-mentioned laminate of the present invention is not particularly limited, but some preferred methods are listed below.
First, in manufacturing the laminate of the present invention, the following two methods are exemplified as a method for preparing the facing surface between the silicone adhesive layer and the peeling layer.

<Method of preparing the facing surface between the silicone adhesive layer and the peeling layer (1)>
The first method for preparing the facing surface is
A step of forming a first release film having a first release layer by applying and curing a release coating agent made of the curable silicone composition of the present invention on a film-like substrate (1);
A curable silicone pressure-sensitive adhesive composition is applied and cured on the same film-like base material as the above-mentioned film-like base material or a second film-like base material different from the above-mentioned film-like base material to form a silicone pressure-sensitive adhesive layer. Step (2); and the step (3) of adhering the release layer of the first release film obtained by the above step (1) on the silicone pressure-sensitive adhesive layer obtained by the above step (2).
Consists of. This preparation method is a method in which an already cured release layer and an already cured silicone pressure-sensitive adhesive layer are brought into contact with each other to form facing surfaces of both layers.

<Method of preparing the facing surface between the silicone adhesive layer and the peeling layer (2)>
The second method of preparing the facing surface is
A step of forming a first release film having a first release layer by applying and curing a release coating agent made of the curable silicone composition of the present invention on a film-like substrate (1);
The step (2); and the above step (2) of applying and curing the curable silicone pressure-sensitive adhesive composition on the first release film obtained by the above step (1) to form a silicone pressure-sensitive adhesive layer. Step of bonding the same film-like substrate as the film-like substrate or the film-like substrate different from the film substrate on the obtained silicone pressure-sensitive adhesive layer (3)
Consists of. This preparation method is a method in which a curable silicone pressure-sensitive adhesive is applied onto an already cured release layer and cured to form facing surfaces of both layers.
In general, the second method often has a higher peeling force difference between the silicone pressure-sensitive adhesive and the peeling agent than the first method.

The above-mentioned structural examples (a) to (d) of the laminate of the present invention can be manufactured, for example, by the same manufacturing method as that disclosed by the applicant in Patent Document 5, and at that time, The release layer is replaced with a cured layer obtained by curing the curable silicone composition of the present invention, and as a silicone pressure-sensitive adhesive layer, the storage elastic modulus at −20 ° C. is 5 MPa or less, preferably 2.5 MPa or less, more preferably. Can use a silicone pressure-sensitive adhesive layer of 1.0 MPa or less. As the facing surface between the silicone pressure-sensitive adhesive and the release agent, the method corresponding to the above-mentioned facing surface preparation method (1) or (2) is appropriately used.

The curable silicone composition and the release film of the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples. In the average composition formula shown below, the symbol Me represents a methyl group and Vi represents a vinyl group. Further, the method for measuring the peeling force when peeling the silicone adhesive from the peeling film is as described below.

<Reference Example 1> Preparation of "Hydrosilylated Curable Silicone Depressant Composition Solution 1" Vinyl-functional polydimethylsiloxane (gum-like (plasticity 152), vinyl content 0.013% by mass) 36.4 parts by mass, (CH ₃ ) ₃ An MQ silicone resin (molecular weight 3300, hydroxyl weight 3.5 mol% (0.8% by mass)) consisting of SiO _1/2 unit, SiO _4/2 unit and hydroxyl group (solid content 75. 5%)) 84.3 parts by mass, 101.6 parts by mass of toluene, dimethylsiloxane / methylhydrogensiloxane copolymer having both ends of the molecular chain sealed with a trimethylsiloxy group (molecular weight 1600, SiH content 0.73%) ) 0.807 parts by weight and 0.577 parts by weight of 1-ethynyl-1-cyclohexanol (20% toluene solution) were mixed well at room temperature, and a platinum-based hydrosilylation reaction catalyst (0.62% by mass of platinum) was added to the mixture. To prepare a uniform solution by mixing 0.484 parts by mass well. The molar ratio (SiH / Vi ratio) of SiH groups in the dimethylsiloxane / methylhydrogensiloxane copolymer with both ends of the molecular chain sealed with trimethylsiloxy groups to the amount of alkenyl groups in vinyl-functional polydimethylsiloxane is 33. 0.7, the content of platinum metal with respect to the solid content was 30 ppm.

<Reference Example 2> Adhesive strength measurement of "hydrosilylated curable silicone pressure-sensitive adhesive composition solution 1" Polyethylene terephthalate (hereinafter abbreviated as PET) film (manufactured by Toray Co., Ltd., product name: Lumirror (registered trademark) S10, thickness 50 μm), apply the “hydrosilylated curable silicone pressure-sensitive adhesive composition solution 1” of the above reference example using an applicator so that the film thickness after curing is 50 μm, and heat at 150 ° C. for 3 minutes. And cured to form a silicone pressure-sensitive adhesive layer. After leaving for 1 day, the sample was cut to a width of 20 mm, and the adhesive layer surface was bonded to a PMMA plate (manufactured by Paltek, acrylicite L001, 50x120x2 mm) using a roller to obtain a test piece. The test piece using the PMMA plate has an adhesive force (at a tensile speed of 300 mm / min) at a tensile speed of 300 mm / min using a 180 ° peeling test method according to JIS Z0237 using an RTC-1210 tensile tester manufactured by Orientec. When the measurement was converted into the display unit gf / inch), it was 1490 gf / inch.

<Reference Example 3> Measurement of Storage Elasticity of "Hydrosilylated Curable Silicone Adhesive Composition Solution 1" On a peeling liner coated with a fluoromodified organopolysiloxane stripping agent, the "hydrosilylated curable silicone adhesive" of the above reference example is applied. The agent composition solution 1 ”was applied using an applicator so that the film thickness after curing was 100 μm, and was heated at 150 ° C. for 3 minutes to be cured to form a silicone pressure-sensitive adhesive layer. Five or more of these pressure-sensitive adhesive layers were superposed to obtain a film sample having a thickness of 500 μm or more and having both sides sandwiched between release liners. The film was hollowed out to a diameter of 8 mm, attached to a parallel plate probe of a dynamic viscoelastic device (MCR301, manufactured by Antonio Par), and the storage elastic modulus at −20 ° C. was measured and found to be 0.52 MPa. The measured temperature was in the range of −70 ° C. to 200 ° C., the frequency was 1 Hz, and the temperature rising rate was 3 ° C./min.

<Measurement method of peeling force>
On a polyethylene terephthalate (hereinafter abbreviated as PET) film (manufactured by Toray Industries, Inc., product name: Lumirror (registered trademark) S10, thickness 50 μm), the thickness of the release agent layer after curing is 0.2 μm. The curable silicone release agent composition was applied to the film using a Mayer bar and heated at 150 ° C. for 3 minutes to prepare a "release film" having a cured silicone release layer. On the release layer of the "release film", the "hydrosilylated curable silicone pressure-sensitive adhesive composition solution 1" of the above reference example was applied using an applicator so that the film thickness after curing was 50 μm, and the temperature was 150 ° C. It was heated for 3 minutes and cured to form a silicone pressure-sensitive adhesive layer. The PET film was bonded onto the obtained silicone pressure-sensitive adhesive layer using a 2 kg hand roller. The obtained film is cut to a width of 1 inch, and the "release film 1" is pulled in a 180 ° direction at a rate of 0.3 m / min with a tensile tester (RTC-1210 manufactured by Orientec) to 25 ° C. The force (peeling force) required to peel the "release film" from the silicone pressure-sensitive adhesive layer was measured.

<Surface condition of silicone adhesive layer after peeling liner>
After measuring the peeling force, the surface state of the silicone adhesive layer after peeling the peeling liner was visually observed. The result is defined as follows.
◯: The surface of the adhesive is uniform and has no roughness or wrinkles. ×: The surface of the adhesive is rough and wrinkled.

[Examples 1 to 4] and [Comparative Examples 1 to 3]
Curable silicone compositions of Examples 1 to 4 and Comparative Examples 1 to 3 were prepared by uniformly mixing each component with the composition shown in Table 1 using the following components. In the formula, Me, Vi, and Pf are methyl group, vinyl group, and 3,3,4,4,5,5,6,6,6-nonafluorohexyl (C ₄ F ₉ CH ₂ CH ₂ ), respectively. ) Represents a group.

(A1): Organopolysiloxane containing a fluoroalkyl group and an alkenyl group having a fluorine atom content of 40% by mass or more Average composition formula:
(Me ₃ SiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₁₄₇₀ (MePfSiO _2/2 ) ₁₁₀₀ (MeViSiO _2/2 ) ₁₀
Fluoroalkyl represented by, having a vinyl group content of 0.060% by mass, a (MePfSiO _2/2 ) unit of 43 mol% of the total diorganosiloxane unit (D unit), and a fluorine content of 42% by mass. Organopolysiloxane containing groups and alkenyl groups.
(A2): Organopolysiloxane containing a fluoroalkyl group and an alkenyl group having a fluorine atom content of less than 40% by mass Average composition formula:
(Me ₂ ViSiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₉₀₀ (Me (Pf) SiO _2/2 ) ₄₅₀ (MeViSiO _2/2 ) ₁₀
The vinyl group content is 0.16% by mass, the (Me (Pf) SiO _2/2 ) unit is 33 mol% of the total diorganosiloxane unit (D unit), and the fluorine atom content is 38% by mass. Organopolysiloxane (B) containing a fluoroalkyl group and an alkenyl group, which is%, average composition formula:
(Me ₃ SiO _1/2 ) ₂ (MePfSiO _2/2 ) ₁₂ (MeHSiO _2/2 ) ₂₇
Organopolysiloxane (C) average composition formula: represented by, the content of fluorine atom is 38% by mass, and the content of silicon atom-bonded hydrogen atom is 0.50% by mass.
(Me ₃ SiO _1/2 ) ₂ (Me ₂ SiO _2/2 ) ₉₀₀ (MePfSiO _2/2 ) ₃₀₀
Organopolysiloxane (D) 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum complex (curable composition as platinum metal amount) represented by, and having a fluorine atom content of 32% by mass. An amount of 270 ppm with respect to the amount of solid content in the medium) was used.
(E) Diisopropyl ether (F) 2-methyl-3-butyne-2-ol

[Mixed test]
When the above (A1) and (A2) were placed in a transparent glass vial with a lid at a mass ratio of 1: 1 and sufficiently stirred and mixed at 25 ° C., the mixture became cloudy and did not become uniformly transparent. rice field. When the mixture was allowed to stand at 25 ° C. and the appearance was observed again after 24 hours, it still remained cloudy. In addition, (A1) and (A2) are transparent liquids at 25 ° C., respectively.

A curable silicone composition is prepared according to the composition shown in Table 1 below, and this is used as a release coating agent to prepare a release film according to the above-mentioned method, and the release film is released from the silicone pressure-sensitive adhesive layer. The peeling force at that time was measured. In addition, the surface condition of the silicone adhesive layer after the release film was peeled off was visually observed.

As described above, the release layer according to the present invention is preferably applied to a silicone pressure-sensitive adhesive having a low storage elastic modulus at a low temperature, but is also applicable to a silicone pressure-sensitive adhesive having a high storage elastic modulus at a low temperature. It is possible, and this is shown in Reference Examples 4 to 7.

<Reference Example 4> Preparation of "Hydrosilylated Curable Silicone Adhesive Composition Solution 2" Hydrosilylated Curable Adhesive DOWNSIL (TM) 7657ADHESIVE (solid content 56% by mass) manufactured by Dow Chemical Co., Ltd. 100.0 parts by mass , 0.42 parts by mass of 4000 CATALYST (platinum metal-containing hydrosilylation reaction catalyst) manufactured by the same company and 33.3 parts by mass of toluene were well mixed to prepare a uniform solution.

<Reference Example 5> Measurement of Adhesive Strength of "Hydrosilylated Curable Silicone Adhesive Composition Solution 2" In Reference Example 2 above, "hydrosilylated curable silicone pressure-sensitive adhesive composition solution 1" is referred to as "hydrosilylated curable silicone pressure-sensitive adhesive". The adhesive strength of "Composition Solution 2" was measured by the same method except that the heating and curing conditions were changed from 150 ° C. for 3 minutes to 140 ° C. for 5 minutes, and it was 1450 gf / inch.

<Reference Example 6> Measurement of storage elastic modulus of "hydrosilylated curable silicone pressure-sensitive adhesive composition solution 2" In Reference Example 3 above, "hydrosilylated curable silicone pressure-sensitive adhesive composition solution 1" is referred to as "hydrosilylated curable silicone pressure-sensitive adhesive". The storage elastic modulus at −20 ° C. was measured by the same method except that the heating and curing conditions were changed from 150 ° C. for 3 minutes to 140 ° C. for 5 minutes in the agent composition solution 2, and it was 9.5 MPa. ..

<Reference Examples 7-1, 7-2> According to the composition shown in Table 2 below, the composition is the same as in Example 3, and the amount of the component (C) is changed to 0.5 parts by mass (Example). 3') Prepare a curable silicone composition, use it as a release coating agent, prepare a release film according to the method described above, and measure the release force when the release film is released from the silicone pressure-sensitive adhesive layer. did. In addition, the surface condition of the silicone adhesive layer after the release film was peeled off was visually observed. The results are shown in Table 2.

[Summary]
The curable silicone compositions of Examples 1 to 4 according to the present invention realize much lower peeling force than Comparative Examples 1 to 3. Further, the surface of the silicone pressure-sensitive adhesive layer after the peeling liner made of the curable compositions of Examples 1 to 4 was peeled off was in a uniform state, and no roughness or wrinkles were observed. On the other hand, when the component (A) is used alone or the component (C) is not used, a sufficient reduction in peeling force can be realized for a silicone adhesive having a low storage elastic modulus at a low temperature. In particular, there is a strong concern that the silicone adhesive layer after peeling will be in a non-uniform state, limiting the range of industrial use. (Comparative Examples 1 to 3)
As confirmed in Reference Examples 7-1 and 7-2, the curable silicone composition according to the embodiment of the present invention can be sufficiently used even for a silicone pressure-sensitive adhesive having a storage elastic modulus exceeding 5 MPa at a low temperature. be.

As shown in Examples, a release film provided with a release layer formed by using the curable silicone composition of the present invention as a release coating agent for a silicone pressure-sensitive adhesive is a silicone pressure-sensitive adhesive, particularly a silicone having a low storage elasticity at low temperature. The curable silicone of the present invention can be peeled off with a weak force, and the surface of the silicone adhesive after peeling off the peeling film can be kept uniform and the occurrence of roughness and wrinkles can be prevented. The composition is useful not only as a conventionally commercially available silicone pressure-sensitive adhesive, but also as a release coating agent for a release film for a silicone pressure-sensitive adhesive having a low storage elasticity at low temperature. Further, the silicone pressure-sensitive adhesive having a low storage elastic modulus at a low temperature tends to be limited in its use because there are few release agents having good compatibility with it, contrary to its excellent performance. However, the release coating agent of the present invention tends to be limited. Will be available in the form of a silicone pressure-sensitive adhesive film / sheet with good peeling properties and low peelability, and it is strongly expected that its industrial application development will be expanded.

Claims (15)

(A) A mixture of two or more kinds of fluoroalkyl group-containing organopolysiloxanes having a fluoroalkyl group and at least two alkenyl groups in one molecule and having different fluoroalkyl group contents from each other. More than one kind of fluoroalkyl group-containing organopolysiloxane is a combination of those that are not completely compatible at 25 ° C. when mixed without solvent. Mixing (B) At least 3 silicon atom-bonded hydrogen atoms in one molecule. Organohydrogenpolysiloxane with individual
(C) Organopolysiloxane having a fluorine atom-containing organic group and no hydrosilylation-reactive group.
A curable silicone composition comprising (D) a catalyst for a hydrosilylation reaction and (E) an organic solvent. (A) Ingredient is
(A1) One or more linear or branched organopolysiloxanes containing a fluoroalkyl group-containing organodisiloxane unit and having a fluorine atom content of 40% by mass or more, and (A2) a fluoroalkyl group-containing organo The curable silicone composition according to claim 1, which is a mixture of one or more linear or branched organopolysiloxanes containing a disiloxane unit and having a fluorine atom content of less than 40% by mass. The rigid silicone composition according to claim 2, wherein the difference between the fluorine atom content (mass%) of the component (A1) and the fluorine atom content (mass%) of the component (A2) is 3% by mass or more. (A) Ingredient is
(A1) Includes a fluoroalkyl group-containing organodisiloxane unit, the fluoroalkyl group is a 3,3,4,4,5,5,6,6,6-nonafluorohexyl group, and the unit is an organosiloxane unit. It contains one or more linear or branched organopolysiloxanes, which are 39 mol% or more of the total, and (A2) fluoroalkyl group-containing organodisiloxane units, and the fluoroalkyl groups are 3, 3, 4, A mixture of one or more linear or branched organopolysiloxanes which are 4,5,5,6,6,6-nonafluorohexyl groups and the unit is 36 mol% or less of the total organosiloxane unit. The curable silicone composition according to any one of claims 1 to 3. The curable silicone composition according to claim 4, wherein the mass ratio of the component (A1) and the component (A2) is (A1) / (A2) = 1/99 to 99/1. The component (C) has one or more trimethylsilyl groups at the end of the molecular chain.
The fluorine atom-containing organic group is one or more groups selected from fluoroalkyl groups having 1 to 12 carbon atoms and fluoro (poly) ether-containing organic groups.
The curable silicone composition according to any one of claims 1 to 5, which is an organopolysiloxane in which the content of fluorine atoms due to the fluorine atom-containing organic group in the molecule is in the range of 20 to 40% by mass. thing. The invention according to any one of claims 1 to 6, wherein the component (B) is an organohydrogenpolysiloxane further having a fluoroalkyl group having 1 to 12 carbon atoms or a fluoro (poly) ether-containing organic group. Curable silicone composition. The amount of the component (B) is 0.1 to 40 parts by mass, the amount of the component (C) is 0.01 to 20 parts by mass, and the amount of the platinum metal of the component (D) is 0.1 to 500 ppm with respect to 100 parts by mass of the component (A). The curable silicone composition according to any one of claims 1 to 7, which contains 20 to 10,000 parts by mass of the component (E). A release coating agent for a silicone pressure-sensitive adhesive, which comprises the curable silicone composition according to any one of claims 1 to 8. The release coating agent for a silicone pressure-sensitive adhesive according to claim 9, wherein the silicone pressure-sensitive adhesive is a silicone pressure-sensitive adhesive having a storage elastic modulus at −20 ° C. of 5 MPa or less. A release film comprising a film-like substrate and a release layer composed of a cured product obtained by curing the curable silicone composition according to any one of claims 1 to 8. A release film for a silicone pressure-sensitive adhesive, which comprises a film-like substrate and a release layer composed of a cured product obtained by curing the release coating agent for a silicone pressure-sensitive adhesive according to claim 9 or 10. A laminate having a structure in which a silicone pressure-sensitive adhesive layer is arranged so as to face at least one release layer, wherein the release layer cures the release coating agent for a silicone pressure-sensitive adhesive according to claim 9. A laminated body that is a release layer made of a cured product. The laminate according to claim 13, wherein the silicone pressure-sensitive adhesive layer is a silicone pressure-sensitive adhesive layer having a storage elastic modulus of 5 MPa or less at −20 ° C. 13. The laminate according to claim 13, wherein the entire laminate has at least one shape selected from i) a laminated sheet and ii) a roll.