KR20220122681A - Curable organopolysiloxane composition, release coating agent and laminate comprising same - Google Patents

Abstract

[Problem] To provide a curable organopolysiloxane composition capable of forming a releasable cured film that forms a cured film exhibiting very excellent release performance without reducing its adhesiveness to an adhesive substance, a release coating agent comprising the same, and a laminate. [Solutions] (A) a chain organopolysiloxane having a viscosity of 1,000,000 mPa·s or more in a liquid phase or a gum shape having a plasticity, and having an alkenyl group only in the side chain of the molecule, (B) a viscosity of 1,000 mPa·s or less, and an alkenyl group A chain organopolysiloxane having a group only in the side chain of the molecule, (C) an organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms (Si-H) in one molecule, and (D) a hydrosilylation reaction catalyst. , wherein the mass ratio {(A)/(B)} of the component (A) to the component (B) is in the range of 95/5 to 5/95, and use as a release coating agent for the curable organopolysiloxane composition.

Description

Curable organopolysiloxane composition, release coating agent and laminate comprising same

The present invention relates to a curable organopolysiloxane composition, and more particularly, to a curable organopolysiloxane composition capable of forming a releasable cured film which forms a cured film exhibiting very excellent peeling performance without reducing its adhesiveness to an adhesive substance; It relates to a release coating agent and a laminate consisting of.

As a silicone composition for forming a releasable cured film for forming a cured film exhibiting excellent peeling performance with respect to an adhesive substance, conventionally, an alkenyl group-containing organopolysiloxane, an organohydrogenpolysiloxane, and a platinum-based catalyst are used, and further, a reaction inhibitor An addition reaction type organopolysiloxane composition made by adding In Patent Documents 1 to 3, in order to improve the performance, a silicone composition for forming a releasable cured film formed by adding an alkenyl group-free organopolysiloxane such as dimethylsiloxane gum or a dimethylsiloxane/methylphenylsiloxane copolymer to these components. This is being proposed. However, these compositions have drawbacks such as a decrease in the adhesiveness of the adhesive substance or a decrease in the printability of the back surface of the film due to migration of the silicone, and thus they are not necessarily satisfactory depending on the application.

In order to solve these problems, in Patent Document 4, it has a functional group selected from the group consisting of a hydroxyl group, an alkenyl group and an alkyl group at the molecular chain terminal, and the viscosity at 25° C. of a 30 wt% toluene solution is 500 centistokes or more. It has been proposed to reduce the peel resistance by mixing two types of high molecular weight siloxanes, but recently, the peel performance required for the release layer (especially the effect of reducing the peel resistance) is further advanced, and the level required as a release coating agent in recent years. may not be reached. Moreover, since two types of high molecular weight siloxanes are mixed, the viscosity of a composition is high, and the composition excellent in handling workability|operativity (handling property) is calculated|required.

Further, in Patent Document 5, a releasable composition comprising a high molecular weight siloxane having a vinyl group at the terminal and having a polymerization degree of siloxane units in the range of 3,000 to 20,000 and siloxane having a viscosity at 25° C. of 0.1 to 500 Pa·s Although proposed, an improvement in the adhesion to the substrate was confirmed, but the performance was still insufficient for solving the problem of realization of the light-peelable property to the adhesive material.

Moreover, in patent document 6, the peelable composition containing two types of siloxanes with a viscosity of 50-10,000 mPa*s and 100,000 mPa*s or more is proposed, Although the objective of providing the slipperiness|lubricacy of a cured film was achieved, similarly to the above Its performance was still insufficient for solving the problem of realization of the light-peelable property for the adhesive material.

Patent Document 1: Japanese Patent Publication No. 53-28943 Patent Document 2: Japanese Patent Laid-Open No. (Hei)2-145650 Patent Document 3: Japanese Patent Publication No. (Hei) 3-52498 Patent Document 4: Japanese Patent Application Laid-Open No. (Hei) 9-125004 Patent Document 5: Japanese Patent Application Laid-Open No. 2004-190202 Patent Document 6: Japanese Patent Application Laid-Open No. 61-159480

The present invention has been made to solve the above problems, and it is possible to form a releasable cured film conforming to the demand for a high degree of peeling performance demanded in the market in recent years, and releasability compatible with suppression of a decrease in the adhesiveness of an adhesive substance. An object of the present invention is to provide a curable organopolysiloxane composition capable of forming a cured film. Another object of the present invention is to provide use of the same composition, specifically, a release coating agent comprising the same, and a laminate comprising a release layer and an adhesive layer using the composition, such as a release adhesive tape/sheet.

As a result of intensive studies, the present inventors found that (A) a liquid having a viscosity of 1,000,000 mPa·s or more at 25°C to a gum phase having a plasticity at 25°C, and an alkenyl group having 2 to 12 carbon atoms in the molecule A chain organopolysiloxane having only a side chain, (B) a chain organopolysiloxane having a viscosity at 25°C of 1,000 mPa·s or less and an alkenyl group having 2 to 12 carbon atoms only in the side chain of the molecule, (C) in one molecule An organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms (Si-H), and (D) a hydrosilylation reaction catalyst, wherein the mass ratio of the component (A) and the component (B) {(A) By using the curable organopolysiloxane composition in which /(B)} is in the range of 95/5 to 5/95, it has been found that the above problems can be solved, and the present invention has been reached.

In addition, in the present invention, the plasticity is the plasticity measured with a plasticity meter in accordance with the method specified in JIS K 6249, specifically, the amount of 1 kgf of a spherical sample at 25°C of 4.2 g (荷量) is the value (unit: mm) when walking for 3 minutes.

In the curable organopolysiloxane composition of the present invention, the mass ratio {(A)/(B)} of the component (A) to the component (B) is preferably in the range of 90/10 to 10/90. Further, in the composition, the mass ratio {(A)/(B)} of the component (A) to the component (B) is in the range of 70/30 to 30/70, and the alkene in the component (A) and the component (B) It is especially preferable that the molar ratio of SiH groups in component (C) with respect to the total number of moles of nyl groups is a quantity used as 0.5-5.

In the curable organopolysiloxane composition of the present invention, the component (A) and the component (B) have an alkenyl group having 4 to 12 carbon atoms only in the side chain of the molecule, and the content of the vinyl (CH ₂ =CH-) moiety in the alkenyl group It is 0.5-3.0 mass %, and it is preferable that the molecular chain terminal is linear organopolysiloxane blocked with the trialkylsilyl group.

In the curable organopolysiloxane composition of the present invention, (E) the organic solvent is an optional component, and the composition may or may not contain an organic solvent. In particular, the composition of the present invention may optionally be in any form comprising (E) an organic solvent, for example solutions and suspensions, with solutions being particularly preferred.

The curable organopolysiloxane composition of the present invention may further contain (F) a hydrosilylation reaction inhibitor and (G) a photopolymerization initiator.

The curable organopolysiloxane composition of the present invention can be suitably used as a release coating agent.

The object of the present invention is solved by a sheet-like article having a cured layer formed by curing the curable organopolysiloxane composition of the present invention and a sheet-like substrate. In particular, it is preferable that the said cured layer is a peelable cured film.

Another object of the present invention is a laminate having a structure in which a pressure-sensitive adhesive layer is disposed opposite to at least one release layer, wherein the release layer is a cured product obtained by curing a release coating agent comprising the curable organopolysiloxane composition of the present invention. It is solved by the laminate, which is a release layer made of

In a release sheet obtained by coating and curing the curable organopolysiloxane composition on a sheet-like substrate, for example, a base film, the release layer made of the composition has excellent peeling performance with respect to the pressure-sensitive adhesive material, and A decrease in adhesiveness can be suppressed. Moreover, the release coating agent which consists of the composition which concerns on this invention can be provided. Similarly, it is possible to provide a laminate comprising a release layer and an adhesive layer using the above composition, such as a peelable adhesive tape/sheet.

Specifically, a release sheet obtained by using the curable organopolysiloxane composition of the present invention as a release layer has excellent releasability with respect to an adhesive substance thereof. Specifically, when an adhesive substance is coated on the surface of a cured layer obtained by curing the curable organopolysiloxane composition of the present invention, dried and cured, the resistance when peeling the release sheet from the coated adhesive substance is can be reduced

The peelable sheet provided with the cured layer obtained by hardening|curing the curable organopolysiloxane composition which concerns on this invention, and the peelable sheet for adhesive substances which concerns on this invention is excellent in coatability to a plastic film. Specifically, when the release agent composition, which is the curable polyorganosiloxane composition of the present invention, is coated on a plastic film, dried and cured, it can be applied uniformly without cissing on the surface of the plastic film, and has a uniform appearance. A peelable sheet can be obtained.

Moreover, the peelable sheet provided with the cured layer obtained by hardening|curing the curable organopolysiloxane composition which concerns on this invention is excellent in maintaining the adhesive force of the adhesive substance. Specifically, after curing the curable organopolysiloxane composition according to the present invention, a pressure-sensitive adhesive material is coated on the surface of the cured layer obtained, dried and cured, and the cured layer (release layer) is peeled from the coated pressure-sensitive adhesive material. It is possible to maintain the original level without deterioration of the adhesive force of the adhesive material.

The curable organopolysiloxane composition of the present invention is (A) a liquid having a viscosity at 25°C of 1,000,000 mPa·s or more, to a gum shape having a plasticity at 25°C, and having an alkenyl group having 2 to 12 carbon atoms only in the side chain of the molecule Chain organopolysiloxane, (B) Chain organopolysiloxane having a viscosity at 25°C of 1,000 mPa·s or less and having an alkenyl group having 2 to 12 carbon atoms only in the side chain of the molecule, (C) 2 or more silicon in one molecule an organohydrogenpolysiloxane having a bonded hydrogen atom (Si-H), and (D) a hydrosilylation reaction catalyst, wherein the mass ratio of the component (A) and the component (B) {(A)/(B) )} is in the range of 95/5 to 5/95, optionally comprising (E) an organic solvent and/or (F) a hydrosilylation reaction inhibitor, and in a particularly preferred embodiment, (G) a photopolymerization initiator. You may. Hereinafter, each component of the curable organopolysiloxane composition and a release sheet for releasing an adhesive substance, which is a release sheet produced using the composition of the present invention, will be described in detail.

The viscosity of the organopolysiloxane at 25°C described in this specification is a value measured with a rotational viscometer. In addition, the plasticity is the plasticity measured with a plasticity meter based on the method prescribed|regulated to JIS K 6249, Specifically, the value (unit) when a load of 1 kgf was applied to a spherical sample of 4.2 g at 25 degreeC for 3 minutes. : mm).

[Component (A)]

Component (A) in the present invention is a so-called organopolysiloxane or an organopolysiloxane mixture having a high degree of polymerization, and its physical properties range from a region showing a high viscosity liquid phase due to an increase in the degree of polymerization, etc., to a region showing a gum shape with plasticity. spread continuously. That is, when the viscosity at 25° C. exceeds 15,000,000 mPa·s due to an increase in the degree of polymerization of the organopolysiloxane, it is generally difficult to measure the viscosity, and the physical properties of the organopolysiloxane from the region (liquid phase) exhibiting higher viscosity are more than plasticity. It shifts to the area (detection image) specified by .

That is, the component (A) of the present invention can measure the viscosity at 25° C., and has a degree of polymerization showing a liquid phase having a viscosity of 1,000,000 mPa·s or more, including a region where the degree of polymerization is higher, including a region at 25° C. It contains gum-like organopolysiloxane or organopolysiloxane mixture that is difficult to measure viscosity and reaches a region such as a degree of polymerization in which physical properties must be specified by plasticity. In particular, it is preferable that the component (A) is an organopolysiloxane or a mixture of organopolysiloxanes having a viscosity at 25°C of 1,000,000 mPa·s or more and a gum shape at 25°C of a plasticity of 3.0 mm or less. Most suitably, the component (A) is an organopolysiloxane or an organopolysiloxane mixture exhibiting a gum shape with a plasticity of 0.5 to 3.0 mm at 25°C.

Component (A) is a chain organopolysiloxane having an alkenyl group having 2 to 12 carbon atoms only in the side chain of the molecule, and one of the features of the invention is that it does not have a reactive functional group such as an alkenyl group at the molecular chain terminal. When it has an alkenyl group at the molecular chain terminal, the high peeling property which is the technical effect of this invention and the effect of suppressing the fall of the adhesiveness with respect to an adhesive substance may not be compatible.

Suitably, the component (A) has an alkenyl group having 2 to 12 carbon atoms only in the side chain of the molecule, and the content of the vinyl (CH ₂ =CH-) moiety in the alkenyl group is 0.5 to 3.0 mass%, and It is preferable that the molecular chain terminal is a linear organopolysiloxane blocked with a trialkylsilyl group.

More preferably, component (A) is a linear organopolysiloxane having a hexenyl group only in the side chain of the molecule as an alkenyl group having 2 to 12 carbon atoms, and both ends of the molecular chain are blocked by trimethylsiloxy groups. In particular, it is preferable that functional groups other than the hexenyl group in component (A) are substantially a methyl group or a phenyl group.

Component (A) can be selected from organopolysiloxane, branched-chain organopolysiloxane, and straight-chain or branched-chain organopolysiloxane containing some cyclic structures, but from an industrial point of view, straight-chain It is preferably an organopolysiloxane of

[Tue 1]

In formula (1), R ¹ is each independently an unsubstituted or halogen atom-substituted alkyl group having 1 to 20 carbon atoms (eg, a methyl group, etc.), an aryl group having 6 to 22 carbon atoms (eg, for example, a phenyl group). R ² is each independently a group selected from R ¹ or a hydroxyl group, and is preferably R ¹ . R ³ is an alkenyl group having 2 to 12 carbon atoms. m is a number greater than or equal to 0, n is a number greater than or equal to 1, and m + n is the organopolysiloxane represented by the formula (1) having a viscosity at 25 ° C. It is the number of the range to be sword imaged. In addition, m, n, R ¹ , R ² and R ³ represent the content of the vinyl (CH ₂ =CH-) moiety in the alkenyl group having 2 to 12 carbon atoms in the organopolysiloxane molecule represented by the formula (1). It is preferable that it is a number used as 0.5-3.0 mass %.

For example, when R ³ in Formula (1) is an alkenyl group having 2 to 12 carbon atoms, the content of the vinyl (CH ₂ =CH-) moiety in the alkenyl group is expressed by the following formula:

(Molecular weight of vinyl moiety of R ³ : about 27) × m/total molecular weight × 100 (mass %)

Component (A) in the formula (1), the content of the vinyl (CH ₂ =CH-) moiety in the alkenyl group having 2 to 12 carbon atoms is in the range of 0.5 to 3.0 mass%, more suitably is an organopolysiloxane satisfying the conditions in the range of 0.5 to 2.0 mass%.

When the content of the vinyl moiety in the alkenyl group in the component (A) is less than the above lower limit, curing reactivity is significantly lowered, so that the amount of migration of the silicone polymer to the tacky material increases, so that the adhesiveness of the tacky material is lowered or peeling from the tacky material. There exists a possibility that peeling of a sheet|seat may become difficult. On the other hand, when content of the vinyl part in an alkenyl group exceeds the said upper limit, there exists a possibility that it may become difficult to peel an adhesive substance from a hardened layer. Moreover, when the viscosity or plasticity of a component (A) deviates from the said range, there exists a possibility that the reduction effect of the peeling resistance intended of this composition may not be acquired.

In addition, in component (A), m + n in formula (1) is the number of ranges from a region in which the organopolysiloxane represented by the formula (1) exhibits a high-viscosity liquid phase to a region in which a gum image having plasticity is exhibited, In particular, it is preferable that the number be the organopolysiloxane exhibiting a liquid phase having a viscosity of 1,000,000 mPa·s or more at 25° C. to the organopolysiloxane exhibiting a gum shape at 25° C. of 3.0 mm or less.

More specifically, as the component (A), an alkenyl group having 2 to 12 carbon atoms, represented by the following formula (2), having a hexenyl group only in the side chain of the molecule, and vinyl (CH ₂ =CH-) in the hexenyl group ) moiety is in the range of 0.5 to 3.0 mass %, and it is particularly preferable that it is a linear organopolysiloxane in which both ends of the molecular chain are blocked by trimethylsiloxy groups.

[Tue 2]

(in formula (2), m1 is a number greater than or equal to 0, n1 is each a positive number, and n1 is a vinyl (-(CH ₂ ) ₄ CH=CH ₂ ) in the hexenyl group in the molecule represented by the formula (2) ( CH ₂ =CH-) moiety content is in the range of 0.5 to 3.0 mass%, more preferably in the range of 0.5 to 2.0 mass%, m1+n1 is the organopolysiloxane represented by formula (2) It is the number of ranges from the region showing the high-viscosity liquid phase to the region showing the gum shape having plasticity, and in particular, the number at which the organopolysiloxane exhibits a liquid phase having a viscosity of 1,000,000 mPa·s or more at 25° C. to the plasticity at 25° C. It is preferable that it is the number used as organopolysiloxane which shows a gum shape of 3.0 mm or less.

The viscosity of component (A) at 25°C is liquid to gum (usually, a semi-solid high degree of polymerization silicone polymer having a viscosity of 10,000,000 mPa·s or more and having plasticity). As described above, the range of physical properties of the highly-polymerized organopolysiloxane or organopolysiloxane mixture, which is a very suitable component (A) in the present invention, varies from a region showing a high-viscosity liquid phase to a gum phase having a plasticity due to an increase in the degree of polymerization, etc. It spreads continuously over the area representing That is, if the viscosity at 25° C. exceeds 15,000,000 mPa·s due to an increase in the degree of polymerization of the organopolysiloxane, it is generally difficult to measure the viscosity, and the physical properties of the organopolysiloxane are plasticized from the higher viscosity region (liquid phase). It shifts to the area|region (sword image) specified by the figure.

Although there is no upper limit of the viscosity of component (A) at 25 ° C., in order not to make handling difficult, it is preferable to exhibit a liquid phase having a viscosity of 1,000,000 mPa·s or more at 25 ° C. to a gum shape having a plasticity of 3.0 mm or less at 25 ° C. .

Component (A) may be a mixture of two or more different components (A). In addition, even if it is a liquid organopolysiloxane having a viscosity at 25°C of less than 1,000,000 mPa·s, or a gum-like organopolysiloxane having a plasticity of more than 3.0 mm at 25°C, it can be handled appropriately by mixing it with other organopolysiloxanes. , and such aspects are also within the scope of the present invention.

When the component (A) is a mixture of two or more types of organopolysiloxanes and the mixture as a whole is gum-like, its plasticity (plasticity measured with a plasticity meter in accordance with the method prescribed in JIS K 6249: spherical shape of 4.2 g at 25°C) It is preferable that the value when 1 kgf is applied to the sample for 3 minutes) is in the range of 0.5-10.0 mm, and it is especially preferable that it exists in the range of 0.5-3.0 mm.

[Component (B)]

Component (B) is a chain organopolysiloxane having a viscosity at 25°C of 1,000 mPa·s or less in a liquid phase and having an alkenyl group having 2 to 12 carbon atoms only in the side chain of the molecule. Component (B) is significantly different from component (A) in viscosity, that is, the degree of polymerization of siloxane, but in that it does not have a reactive functional group such as an alkenyl group at the molecular chain terminal, component (A) and component (B) have a common structure, , when it has an alkenyl group at the molecular chain terminal, it may not be compatible with the high peeling property which is the technical effect of this invention, and the effect of suppressing the fall of the adhesiveness with respect to an adhesive substance.

Suitably, the component (B) has an alkenyl group having 2 to 12 carbon atoms only in the side chain of the molecule, and the content of the vinyl (CH ₂ =CH-) moiety in the alkenyl group is 0.5 to 3.0 mass%, and its It is preferable that the molecular chain terminal is a linear organopolysiloxane blocked with a trialkylsilyl group.

Component (B) can be selected from straight-chain organopolysiloxane, branched-chain organopolysiloxane, and straight-chain or branched-chain organopolysiloxane having a partial cyclic structure. From an industrial point of view, It is preferable that it is a linear organopolysiloxane.

[Tuesday 3]

In formula (3), R ¹¹ is each independently an unsubstituted or halogen atom-substituted alkyl group having 1 to 20 carbon atoms (eg, a methyl group, etc.), an aryl group having 6 to 22 carbon atoms (eg, for example, a phenyl group). R ¹² is each independently a group selected from R ¹¹ or a hydroxyl group, and is preferably R ¹¹ . R ¹³ is an alkenyl group having 2 to 12 carbon atoms. m' is a number greater than or equal to 0, n' is a number greater than or equal to 1, and m'+n' is a number in a range in which the organopolysiloxane represented by the formula (3) has a viscosity at 25°C of 1,000 mPa·s or less. to be. In addition, m', n', R ¹¹ , R ¹² and R ¹³ are the vinyl (CH ₂ =CH-) moieties in the alkenyl group having 2 to 12 carbon atoms in the organopolysiloxane molecule represented by the formula (3). It is a number used as content 0.5-3.0 mass %.

For example, when R ¹³ in Formula (3) is an alkenyl group having 2 to 12 carbon atoms, the content of the vinyl (CH ₂ =CH-) moiety in the alkenyl group is expressed by the following formula:

(Molecular weight of vinyl moiety of R ¹³ : about 27) x m / total molecular weight x 100 (mass %)

Component (B) in the formula (3), the content of the vinyl (CH ₂ =CH-) moiety in the alkenyl group having 2 to 12 carbon atoms is in the range of 0.5 to 3.0 mass%, more preferably is an organopolysiloxane satisfying the conditions in the range of 0.5 to 2.0 mass%.

When the content of the vinyl moiety in the alkenyl group in the component (B) is less than the above lower limit, curing reactivity is significantly lowered, so that the amount of migration of the silicone polymer to the adhesive substance increases, and the adhesiveness of the adhesive substance decreases or peeling from the adhesive substance There exists a possibility that peeling of a sheet|seat may become difficult. On the other hand, when content of the vinyl part in an alkenyl group exceeds the said upper limit, there exists a possibility that it may become difficult to peel an adhesive substance from the peeling layer obtained by hardening.

In the component (B), m'+n' in the formula (3) is a range in which the organopolysiloxane represented by the formula (3) exhibits a liquid phase of 1,000 mPa·s or less at 25°C, and 5 to 500 mPa·s It is particularly preferable to be in the range of When the viscosity of component (B) exceeds 1,000 mPa*s, even when it uses together with component (A), there exists a possibility that the reduction effect of the intended peeling resistance of this composition may not be acquired.

More specifically, as the component (B), an alkenyl group having 2 to 12 carbon atoms, represented by the following formula (4), having a hexenyl group only in the side chain of the molecule, and vinyl (CH ₂ =CH-) in the hexenyl group ) moiety is in the range of 0.5 to 3.0 mass %, and it is particularly preferable that it is a linear organopolysiloxane in which both ends of the molecular chain are blocked by trimethylsiloxy groups.

[Tue 4]

(in formula (4), m1' is a number greater than or equal to 0, n1' is a positive number, and n1' is a hexenyl group (-(CH ₂ ) ₄ CH=CH ₂ ) in the molecule represented by the formula (4). The content of the vinyl (CH ₂ =CH-) moiety is in the range of 0.5 to 3.0 mass%, more preferably in the range of 0.5 to 2.0 mass%. It is preferable that the viscosity at 25 degreeC of the organopolysiloxane used is a number used as 1,000 mPa*s or less.

Component (B) may be a mixture of two or more different components (B). Moreover, even if it is an organopolysiloxane whose viscosity at 25 degreeC exceeds 1,000 mPa*s, it may be suitably handled by setting it as a mixture with other organopolysiloxane, and such an aspect is also within the scope of the present invention.

When component (B) is a mixture of two or more types of organopolysiloxane, it is especially preferable that the viscosity of the mixture at 25 degreeC is 1,000 mPa*s or less, and becomes the range of 5-500 mPa*s.

[Mass ratio of component (A) and component (B) {(A)/(B)}]

The present invention has a similar siloxane structure and uses the component (A) and component (B), which have a similar siloxane structure and whose viscosity (siloxane polymerization degree) are significantly different, together in a specific mass ratio range, thereby suppressing a decrease in adhesion to an excellent peeling property and adhesive material It is possible to reconcile technological effects.

Specifically, the mass ratio {(A)/(B)} of the component (A) to the component (B) is preferably in the range of 95/5 to 5/95, and in the range of 90/10 to 10/90. It is more preferable to exist, and it is still more preferable to exist in the range of 70/30-30/70. When the mass ratio (A)/(B) is greater than 95/5, the reduction of the peeling resistance does not reach a sufficient level, and there is a fear that it becomes difficult to peel the release sheet from the pressure-sensitive adhesive material. Moreover, when mass ratio (A)/(B) is smaller than 5/95, it becomes difficult to apply uniformly on sheet-like base materials, such as a plastic film, and there exists a possibility that the external appearance of a peeling sheet may become poor.

[Component (C)]

Component (C) is an organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms (Si-H) in one molecule, and is a crosslinking agent for the components (A) and (B). The component (C) preferably has at least three silicon atom-bonded hydrogen atoms in one molecule, and the bonding position of the hydrogen atoms in the molecule is not particularly limited. Moreover, as an organic group couple|bonded with the silicon atom contained in component (C) other than a hydrogen atom, alkyl groups, such as a methyl group, an ethyl group, a propyl group, a butyl group, and an octyl group, are illustrated, It is preferable that it is a methyl group. In addition, as the molecular structure of the organohydrogenpolysiloxane of component (C), linear, branched, and branched cyclic any or a combination of one or more thereof is exemplified. In addition, the number of silicon-bonded hydrogen atoms in one molecule is an average value of all molecules.

The viscosity at 25°C of component (C) is 1 to 1,000 mPa·s, preferably 5 to 500 mPa·s. This means that when the viscosity of component (C) at 25° C. is less than 1 mPa·s, component (C) tends to volatilize from the curable organopolysiloxane composition containing it, and when it exceeds 1,000 mPa·s, curable organopolysiloxane This is because the curing time of the nopolysiloxane composition becomes long.

Although this component (C) is not specifically limited, For example, a dimethylsiloxane/methylhydrogensiloxane copolymer blocked with trimethylsiloxy groups at both terminals, a dimethylsiloxane/methylhydrogensiloxane copolymer blocked with dimethylhydrogensiloxy groups at both terminals, and both terminals. Dimethylpolysiloxane blocked with dimethylhydrogensiloxy groups, methylhydrogenpolysiloxane with both terminals blocked with trimethylsiloxy groups, cyclic methylhydrogenpolysiloxane, and cyclic methylhydrogensiloxane/dimethylsiloxane copolymers are exemplified. Component (C) is one type of organohydrogenpolysiloxane represented by the following general formula (5) or a mixture of two or more types of organohydrogenpolysiloxane, and is a silicon atom bond contained in components (A) and (B) By addition reaction (hydrosilylation reaction) with an alkenyl group, a layer of cured organopolysiloxane can be formed.

[Tue 5]

In formula (5), R ²¹ is an unsubstituted or substituted alkyl or aryl group, preferably an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or a phenyl group. R ²² is each independently a group represented by R ¹² or a hydrogen atom (-H), but when q=0, R ²² is a hydrogen atom (-H). p and q are numbers greater than or equal to 0, and p+q is a number in the range where the viscosity at 25°C of the organopolysiloxane represented by the formula (5) is 1 to 1,000 mPa·s.

The compounding amount of component (C) in the curable organopolysiloxane composition of the present invention is a SiH group with respect to the total number of moles of alkenyl groups (including vinyl moieties composed of carbon-carbon double bonds) in components (A) and (B). is an amount in which the molar ratio of is 0.5 to 5.0, preferably 1.0 to 3.0. When the molar ratio is smaller than the lower limit, the curable organopolysiloxane composition obtained decreases in curability. When the molar ratio exceeds the upper limit, the peel resistance of the release layer obtained by curing with respect to the adhesive substance increases, so that practical peelability cannot be obtained. there is a risk of becoming

[Component (D)]

Component (D) is a hydrosilylation reaction catalyst, and is a catalyst which promotes the addition reaction (hydrosilylation reaction) of a silicon atom-bonded alkenyl group and a silicon atom-bonded hydrogen atom present in the curable organopolysiloxane composition. A preferred hydrosilylation reaction catalyst is a hydrosilylation reaction catalyst containing a platinum-based metal, specifically, chloroplatinic acid, alcohol-modified chloroplatinic acid, an olefin complex of chloroplatinic acid, a complex of chloroplatinic acid and ketones, and a complex of chloroplatinic acid and vinyl siloxane. Complex, platinum tetrachloride, platinum fine powder, solid platinum supported on alumina or silica carrier, platinum black, platinum olefin complex, platinum alkenylsiloxane complex, platinum carbonyl complex, and methyl meta containing these platinum catalysts Platinum-based catalysts of thermoplastic organic resin powder such as acrylate resin, polycarbonate resin, polystyrene resin, and silicone resin are exemplified. In particular, platinum alkenyl, such as a complex of chloroplatinic acid and divinyltetramethyldisiloxane, a complex of chloroplatinic acid and tetramethyl tetravinyl cyclotetrasiloxane, a platinum divinyltetramethyldisiloxane complex, and a platinum tetramethyltetravinyl cyclotetrasiloxane complex A siloxane complex can be preferably used.

The amount of the component (D) added to the curable organopolysiloxane composition may be any catalytic amount, and usually, the component (D) contains with respect to the total amount of the components (A) to (C) of the curable organopolysiloxane composition of the present invention. The amount of the platinum-based metal is preferably in the range of 1 to 1,000 ppm, and still more preferably the amount in the range of 5 to 500 ppm.

[Other components (E) to (G) and overall viscosity of the composition]

The curable organopolysiloxane composition according to the present invention may optionally contain (E) an organic solvent. In particular, since the curable organopolysiloxane composition according to the present invention has a large content of the component (A), in order to improve handling workability and coatability, the components (A) to (D) are added to a known (E) organic solvent. It is preferable to use by dispersing or dissolving a composition comprising a. However, unless it is contrary to the purpose of the present invention, a low-viscosity liquid organopolysiloxane other than any organic solvent (for example, a chain or cyclic organo having a low viscosity of about 0.5 to 10 mPa·s at 25°C) It is also possible to use by dispersing or dissolving the components (A) to (D) in polysiloxane). Organic solvents include aromatic hydrocarbon solvents such as toluene and xylene, aliphatic hydrocarbon solvents such as hexane, octane and isoparaffin, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and ethyl acetate and isobutyl acetate. ester solvents, ether solvents such as diisopropyl ether and 1,4-dioxane; cyclic polysiloxanes having a polymerization degree of 3 to 6, such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane; and and halogenated hydrocarbons such as trichloroethylene, perchlorethylene, trifluoromethylbenzene, 1,3-bis(trifluoromethyl)benzene and methyl pentafluorobenzene. When the curable organopolysiloxane composition of the present invention is thinly coated on a sheet-like substrate such as polyolefin having low heat resistance, the effect on the curability of the composition is small, so the use of an aromatic hydrocarbon solvent such as toluene or xylene is preferable.

The curable organopolysiloxane composition of the present invention, in addition to the above components (A) to (D) and optionally component (E), suppresses gelation and curing at room temperature to improve storage stability, and at the same time to make it curable upon heating, ( F) It is preferable to further contain a hydrosilylation reaction inhibitor. As a hydrosilylation reaction inhibitor, an acetylenic compound, an ene compound, an organic nitrogen compound, an organophosphorus compound, and an oxime compound are illustrated. Specific examples of the compound include 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-pentyn-3-ol, 2-phenyl-3-butyne- alkyne alcohols such as 2-ol and 1-ethynyl-1-cyclohexanol (ETCH); 3-Methyl-3-trimethylsiloxy-1-butyne, 3-methyl-3-trimethylsiloxy-1-pentyne, 3,5-dimethyl-3-trimethylsiloxy-1-hexyne, 3-methyl-3- ene compounds such as pentene-1-yne and 3,5-dimethyl-3-hexene-1-yne; 1-ethynyl-1-trimethylsiloxycyclohexane, bis(2,2-dimethyl-3-butynoxy)dimethylsilane, 1,3,5,7-tetramethyl-1,3,5,7-tetra and alkenylsiloxanes such as vinyl cyclotetrasiloxane and 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenyl cyclotetrasiloxane.

The addition amount of the (F) hydrosilylation reaction inhibitor to the curable organopolysiloxane composition is usually within the range of 0.001 to 5 parts by mass of the component (F) per 100 parts by mass of the component (A), but the type of the component (F) and the hydrosilyl to be used Characteristics and usage of the reaction catalyst, the content of C2 to C12 alkenyl groups in the components (A) and (B), the amount of silicon atom-bonded hydrogen atoms in the component (C), and the desired pot life for the curable composition And it can easily determine the preferable usage-amount of a component (F) suitably according to a work environment.

The curable organopolysiloxane composition of the present invention comprises the above components (A) to (D), optionally component (E), and further component (F), and at room temperature or 50 to 200° C. (D ) by carrying out the addition reaction in the presence of a hydrosilylation reaction catalyst, a cured film having excellent peeling properties can be formed.

Further, since the obtained cured film has excellent physical properties and releasability, it is preferable to cure the curable organopolysiloxane composition of the present invention by irradiation with energy rays (also referred to as chemical action rays), for example, ultraviolet rays or electron rays, especially ultraviolet rays. do. In this case, UV curing can be performed only by UV curing or by using UV curing and heat curing in combination. The curing time of the curable composition can be appropriately adjusted according to the curing conditions to be used. In order to provide favorable ultraviolet curability to the curable organopolysiloxane composition of this invention, it is preferable to further mix|blend (G) a photoinitiator with a composition. Hereinafter, component (G) is demonstrated.

(G) The photopolymerization initiator is a component that imparts UV curability to the curable organopolysiloxane composition of the present invention, and by using thermal curing and UV curing by addition reaction in combination, heat damage to the plastic film substrate with low heat resistance is reduced. , there is an advantage in that the adhesiveness of the cured product of the present invention to a plastic film is improved. In addition, the silicone component migrates onto the sheet from the surface of the cured film made of the curable composition of the present invention, thereby preventing the sheet from being contaminated by the silicone component (this is referred to as silicone migration property), thereby further reducing the silicone migration property. There is an advantage that you can. The component (G) can be appropriately selected from among known compounds that generate radicals upon irradiation with ultraviolet rays, for example, organic peroxides, carbonyl compounds, organic sulfur compounds, and azo compounds. Specific examples of the compound include acetophenone, propiophenone, benzophenone, xanthol, fluorine, benzaldehyde, anthraquinone, triphenylamine, 4-methylacetophenone, 3-pentylacetophenone, 4-methoxyacetophenone, 3-bro Moacetophenone, 4-allylacetophenone, p-diacetylbenzene, 3-methoxybenzophenone, 4-methylbenzophenone, 4-chlorobenzophenone, 4, 4-dimethoxybenzophenone, 4-chloro-4- Benzylbenzophenone, 3-chloroxanthone, 3, 9-dichloroxanthone, 3-chloro-8-nonylxanthone, benzoin, benzoin methyl ether, benzoin butyl ether, bis(4-dimethylaminophenyl)ketone, benzylme Toxiketal, 2-chlorothioxanthone, diethylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl[4-(methylthio)phenyl]2-morpholino-1-propanone, 2,2- Dimethoxy-2-phenylacetophenone, diethoxyacetophenone, etc. are mentioned. When the composition of the present invention is cured with ultraviolet light, as component (G), benzophenone, 4-methoxyacetophenone, 4-methylbenzophenone, diethoxyacetophenone and 1-hydroxycyclohexyl phenyl ketone are preferable. As a particularly preferable component (G), diethoxyacetophenone and 1-hydroxycyclohexyl phenyl ketone are mentioned.

The said (G) photoinitiator may be used individually by 1 type, or may use 2 or more types together. Although the compounding quantity is not specifically limited, It is the range of 0.01-10 mass parts with respect to 100 mass parts of (A) component, Preferably it is the range of 0.01-2.5 mass parts. (G) When the compounding quantity of the component is within the range described above, the peelable cured film obtained by curing the composition of the present invention has improved silicone migration properties and is excellent in physical properties such as strength.

The curable organopolysiloxane composition of the present invention is suitable for use as a solution-type curable organopolysiloxane composition containing (E) an organic solvent. In particular, in the curable organopolysiloxane composition of the present invention, in order to obtain good coating properties of the composition on a sheet-like substrate, the viscosity of the entire composition at 25° C. is preferably in the range of 100 to 100,000 mPa·s, and the entire composition It is more preferable that the viscosity is 100-50,000 mPa·s.

[Other optional ingredients]

In addition to the said component, arbitrary components other than that can further be added to curable organopolysiloxane composition of this invention. As another optional component, For example, the adhesion promoter which consists of alkoxysilane compounds, such as 3-glycidoxy propyl trimethoxysilane and 3-methacryloxy propyl trimethoxysilane; antioxidants such as phenol, quinone, amine, phosphorus, phosphite, sulfur and thioether; Light stabilizers, such as a triazole type and a benzophenone type; flame retardants such as phosphoric acid ester, halogen, phosphorus and antimony; at least one surfactant selected from cationic surfactants, anionic surfactants and nonionic surfactants; and known additives such as antistatic agents, heat resistance agents, dyes and pigments, and one or two or more components selected from these may be added to the curable organopolysiloxane composition of the present invention in combination.

[Method for producing composition]

When using the above components (A) to (D), optionally components (E), (F), (G), and other optional components, the composition of the present invention can be prepared by further mixing them uniformly. . Although the order of addition of each component is not specifically limited, When the obtained composition is not used immediately after mixing, the mixture of component (A), component (B), and component (C) and component (D) are stored separately It is preferable to mix both immediately before use. In addition, in the composition consisting of components (A) to (D), optionally other components such as component (E), (F) by adjusting the type and blending amount of the hydrosilylation reaction inhibitor, there is no crosslinking at room temperature, A composition made to crosslink and harden when heated is also preferable.

[Use of composition: release coating agent and release sheet]

The curable organopolysiloxane composition of the present invention can be suitably used as a release coating agent, the same composition is uniformly coated on a sheet-like substrate, and the components (A) to (C) undergo hydrosilylation reaction under conditions sufficient for crosslinking. When heating, irradiation with energy rays (for example, ultraviolet rays, electron beams, etc.), or a combination thereof is used under heating, peeling having a release layer composed of a cured silicone film (i.e., cured organopolysiloxane) film on the surface of a sheet-like substrate A castle sheet is obtained. The release sheet according to the present invention has good coatability of the adhesive substance on the cured silicone film, and it is easy to peel the adhesive substance after drying from the substrate, and the adhesiveness and adhesive strength of the adhesive substance are not reduced. have That is, the release sheet of the present invention obtained in this way can be suitably used as a release sheet for adhesive substances. In addition, since the cured layer formed by curing the curable composition of the present invention has excellent flexibility, it has an advantage in that it has good followability to a substrate and less entrainment of air bubbles even when it is pasted on a non-planar object. Therefore, it can be extremely suitably used for applications that require both the peeling properties of the cured layer and the adhesion properties of the cured layer to the object to be protected, such as an optical display or a protective film on a glass surface.

There is no restriction|limiting in particular as a sheet-like base material for coating the curable polyorganosiloxane composition of this invention, Any thing can be used suitably selecting from conventionally well-known materials. As such a base material, For example, polyester, such as a polyethylene terephthalate and a polyethylene naphthalate; polyolefins such as polypropylene and polymethylpentene; polycarbonate; and films made of plastics such as polyvinyl acetate. This film may be a single layer or may be composed of a multilayer of two or more layers made of the same or different types of plastics. As a sheet-like base material used for this invention, a plastic film, especially a polyester film, is preferable, and a polyethylene terephthalate film is especially preferable. Especially, it is preferable to use a biaxially stretched polyethylene terephthalate film as a sheet-like base material. The polyethylene terephthalate film hardly generates dust during processing and use. Accordingly, it is possible to effectively prevent coating failure of the adhesive substance on the sheet-like substrate caused by dust or the like. In addition, performing antistatic treatment on a polyethylene terephthalate film and using it as a sheet-like substrate is also effective in preventing occurrence of poor coating of the adhesive substance on the sheet-like substrate.

In addition, in order to improve the adhesion between the curable organopolysiloxane of the present invention coated and cured on the surface of the sheet-like substrate and the surface of the sheet-like substrate, if desired, on one or both sides of the sheet-like substrate by an oxidation method or an unevenness method, etc. A surface treatment or a primer treatment can be performed. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone treatment, and ultraviolet irradiation treatment. and a thermal spray treatment method. For these surface treatment methods, a suitable method can be selected depending on the type of the sheet-like substrate, and since the desired effect obtained by the surface treatment of the sheet-like substrate is high and the operation is simple, the corona discharge treatment method is preferred. .

The thickness of the sheet-like substrate is generally 10 to 300 μm, preferably 15 to 200 μm, and particularly preferably 20 to 125 μm.

The coating method of the curable organopolysiloxane composition of the present invention on a sheet-like substrate can be performed using any known method, for example, a gravure coating method, a bar coating method, a spray coating method, a spin coating method, and a knife. A coating method, a roll coating method, a die coating method, etc. can be used.

When the curable organopolysiloxane composition of the present invention is coated and cured on a sheet-like substrate, the thickness of the layer of the cured organopolysiloxane composition is not particularly limited, but is preferably 0.01 to 3 μm, and preferably 0.03 to 1 μm. even more preferred. When the thickness of the layer of the cured organopolysiloxane composition on the sheet-like substrate is less than 0.01 μm, when it is used as a release sheet for an adhesive material, there is a fear that the layer may not exhibit a sufficient function as a release agent layer. On the other hand, when the thickness of the layer of the cured organopolysiloxane composition on the sheet-like substrate exceeds 3 µm, blocking may occur when the resulting release sheet is wound into a roll. In addition, the antistatic layer and other layers other than the above-described antistatic layer may be optionally provided on the surface of the sheet-like substrate opposite to the cured organopolysiloxane composition layer, or between the sheet-like substrate and the organopolysiloxane composition layer. have.

[Laminate]

The curable organopolysiloxane composition of the present invention can be used as a release layer-forming organopolysiloxane composition (= release coating agent) for use in forming a release layer in the production of a release laminate typified by an adhesive sheet or the like. Specifically, the laminate according to the present invention is a laminate having a structure in which a pressure-sensitive adhesive layer is disposed opposite to at least one release layer, wherein the release layer is a cured product obtained by curing the release coating agent according to the present invention. It is characterized in that it is a peeling layer made of. Here, the release layer is preferably formed on a sheet-like substrate, and the composition according to the present invention is for an adhesive substance having a sheet-like substrate and a cured layer obtained by coating and curing the curable organopolysiloxane composition of the present invention thereon. It is suitable for use as a release sheet, and this release sheet for the pressure-sensitive adhesive material is also suitable for forming a pressure-sensitive adhesive material laminate comprising the pressure-sensitive adhesive material and the release sheet for the pressure-sensitive adhesive material.

This adhesive material laminate can be produced by a method comprising a step of coating the adhesive substance on the release sheet for the adhesive substance of the present invention, that is, on the side of the side of the cured polyorganosiloxane composition, and drying/curing the adhesive substance. have. More specifically, by using any coating method, for example, the slot die coating method or the doctor blade method, the adhesive material is applied to the surface of the layer of the cured organopolysiloxane composition formed on the release sheet for the adhesive material of the present invention. and drying/curing again to form an adhesive material laminate. Thereafter, it is optional to attach a sheet-like substrate coated with or not coated with the curable organopolysiloxane composition of the present invention to the pressure-sensitive adhesive material layer. The release sheet for an adhesive material of the present invention has excellent peelability from the adhesive material laminate, and can be peeled from the adhesive material layer with a low peeling force without causing defects such as breakage in the adhesive material. In addition, as described above, the curable organopolysiloxane composition of the present invention has a feature that does not reduce the adhesiveness and adhesive strength of the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive material.

As another form of the adhesive material laminate, the adhesive material is dried/cured on a sheet-like substrate not coated with the curable organopolysiloxane composition of the present invention, and then the release sheet for the adhesive material of the present invention is applied on the adhesive material. It can also be produced by a method including a pasting process. Even in this form, the release sheet for the pressure-sensitive adhesive material of the present invention has excellent peelability from such a pressure-sensitive adhesive material layered body, and can be peeled from the pressure-sensitive material layer with a low peel force without causing defects such as breakage in the pressure-sensitive adhesive material, Moreover, it has the characteristic that the adhesiveness and adhesive force of an adhesive layer are not reduced.

Although the curable organopolysiloxane composition of the present invention is suitable for use as a release sheet for an adhesive material as described above, the use is not limited thereto, and it can be used for surface treatment of various films and sheets. In particular, the release sheet having a cured layer made of the composition of the present invention is used for protecting the surface of optical components such as liquid crystal panels, plasma displays, polarizing plates and retardation plates, or electrical/electronic components such as printed wiring boards, ICs, transistors, and capacitors. It can also use as a surface protection film, In that case, it is preferable to add an antistatic agent to the composition of this invention.

As the antistatic agent, a known ionic or nonionic antistatic agent can be used without particular limitation, and a method of adding a silicone oil having a hydrophilic group to the main component (Japanese Patent Application Laid-Open No. 52-103499), a sulfonate Method of adding (Japanese Patent Publication No. Hei 3-59096), Method of adding fluorinated silicone oil (Japanese Patent Application Laid-Open No. Hei 1-83085, Japanese Patent Application Laid-Open No. Hei 1- 83086, Japanese Patent Application Laid-Open No. Hei1-121390), a method of adding a silicone oil containing a surfactant (Japanese Patent Application Laid-Open No. Hei 1-294099), a method of adding a conductive powder ( Japanese Patent Application Laid-Open No. (Hei) 2-69763, Japanese Unexamined Patent Application (Kokai) No. 3-292180, and Japanese Unexamined Patent Application (Kokai) No. 4-86765) can be exemplified. In particular, from the standpoint of compatibility with the curable organopolysiloxane composition of the present invention, the use of an antistatic agent that is a lithium salt or a polyether-modified polysiloxane is very suitable. These ionic antistatic agents or polyether-modified polysiloxanes, for example, are specifically limited to those disclosed in JP 2009-30028 , JP 2012-157978 , JP 2011-178828 . can be used without In addition, from the standpoint of antistatic, treatment with antistatic agents such as surfactants, silicon-based, organic boron-based, conductive polymer-based, metal oxide-based, and vapor-deposited metal-based agents may be performed as well as use as an additive of the above antistatic agent. .

Example

Hereinafter, the present invention will be described in more detail by showing examples of the present invention together with comparative examples, but the present invention is not limited to the following examples. In addition, in the following examples, "part" indicating the quantity means parts by mass, and the vinyl (CH ₂ =CH-) moiety represents a vinyl (CH ₂ =CH-) group moiety in the alkenyl group bonded to a silicon atom, and molecular weight Content of the said vinyl part which occupies for the whole is represented by mass %, and when the said alkenyl group is a vinyl group, it is simply called "vinyl group content." Viscosity and plasticity are values measured at 25°C. The method for measuring the plasticity was as described above, and the measurement of the viscosity was performed using a digital display type B rotational viscometer (Bismetron VDA2 type manufactured by Shibaura Systems Co., Ltd.).

[Manufacturing method of release sheet]

Apply the curable organopolysiloxane composition to the surface of a biaxially stretched polyester film (manufactured by Mitsubishi Plastics, Inc., thickness 38 μm) using a Mayer bar in an amount of 0.15 g/m2 in terms of solid content excluding solvent. was painted. After coating, by heat-treating the substrate coated with the composition at 120° C. for 30 seconds in a hot air circulation oven, a cured layer of organopolysiloxane is formed on the surface of the polyester film substrate, and in air at a temperature of 25° C. and a humidity of 60% It was stored for 72 hours to prepare a release sheet.

[Evaluation of Coatability]

The above-mentioned release sheet was visually observed for the uniformity of the coated surface, and the thing of a uniform external appearance was made into pass, and the thing of a non-uniform external appearance was made into rejection.

[Measurement of adhesive peel resistance]

Adhesive tape made by TESA The TESA7475 tape was affixed to the obtained release sheet, a load of 20 g/cm ² was applied, and it was left to stand in the air of the temperature of 25 degreeC, and a humidity of 60% for 24 hours. After that, using a tensile tester (Tensilon universal tester manufactured by A&D Company, Limited), the adhesive tape was pulled under the conditions of an angle of 180 degrees and a peeling rate of 0.3 m/min, as required for peeling. One force (mN/50 mm) was measured. When the peeling force by this method was 55 mN/5 cm or less, the peeling properties were good, and when it exceeded 55 mN/50 mm, it was judged that the peeling properties were poor.

[Measurement of residual adhesion rate]

On the release sheet, Nitto Denko Corporation adhesive tape No. 31B was attached, a load of 20 g/cm ² was applied, and the mixture was left at a temperature of 70° C. for 20 hours. Next, the adhesive tape is peeled off, the peeled adhesive tape is attached to a stainless steel plate, a load of 20 g/cm ² is applied, and the adhesive tape is left in air at a temperature of 25° C. and a humidity of 60% for 30 minutes, followed by a tensile tester [A&D, Inc.] Tensilon universal testing machine], the adhesive tape was pulled under the conditions of an angle of 180 degrees and a peeling rate of 0.3 m/min, and the force (gf1) required for peeling was measured. In addition, as a blank test, the tape was applied to a Teflon (registered trademark) sheet in the same manner as described above, and the force (gf2) required for peeling the adhesive tape was measured in the same manner as above. From these values, the residual adhesion rate (%) was calculated according to the following formula.

Residual adhesion rate (%) = (gf1/gf2) × 100

The residual adhesion rate made 95% or more a pass, and made less than 95% a rejection.

[Example 1] Composition 1

(A) (a-1) Polydimethylsiloxane having both ends of the molecular chain blocked with methyl groups and having a hexenyl group in the side chain (plasticity 1.15, content of the vinyl (CH ₂ =CH-) moiety in the hexenyl group 0.80 mass% ) 66.7 parts, (B) (b-1) 33.3 parts of dimethylsiloxane (viscosity 350 mPa·s, vinyl group content 1.20 mass%) having a methyl group blocked at the molecular chain terminal and having a hexenyl group in the side chain (C) viscosity The amount of dimethylmethylhydrogenpolysiloxane blocking trimethylsiloxy groups at both ends of the molecular chain of 25 mPa·s so that the SiH/Vi ratio in the total composition is 1.2, (E) 100.0 parts of toluene and (F) 3-methyl-1-butyne-3 - 1.5 parts of all were uniformly mixed to obtain a solvent-containing curable organopolysiloxane composition (composition 1-1). Further, the obtained organopolysiloxane composition was diluted with (E) toluene/hexane = 50/50 wt% mixed solution so that the solid content concentration was 5.0 mass%, (D) chloroplatinic acid·1,3-divinyl-1,1; A release sheet was obtained by the above method using a 3,3-tetramethyldisiloxane complex added and blended in an amount such that the amount of platinum metal was 200 ppm with respect to the total amount of the components (A) to (C). The external appearance observation of the release sheet obtained in this way, and evaluation of the peeling force and the residual adhesive rate were performed, and these are shown in Table 1.

[Example 2] Composition 2

Except having changed the usage-amount of (A) component of Example 1 into 50.0 parts and the usage-amount of (B) component into 50.0 parts, it carried out similarly to Example 1, and obtained the composition 2. The external appearance observation of the release sheet obtained in this way, and evaluation of the peeling force and the residual adhesive rate were performed, and these are shown in Table 1.

[Example 3] Composition 3

Except having changed the usage-amount of (A) component of Example 1 into 33.3 parts and the usage-amount of (B) component into 66.7 parts, it carried out similarly to Example 1, and obtained the composition 3. The external appearance observation of the release sheet obtained in this way, and evaluation of the peeling force and the residual adhesive rate were performed, and these are shown in Table 1.

[Comparative Example 1] Comparative Composition 1

Example 1 except that (B) component of Example 1 was not used, the usage amount of component (A) was changed to 100.0 parts, the usage amount of component (E) was changed to 333.3 parts, and the usage amount of component (F) was changed to 0.9 parts. Comparative composition 1 was obtained in the same manner as described above. The external appearance observation of the release sheet obtained in this way and evaluation of the peeling force and residual adhesion rate were performed, and these are shown in Table 1.

[Comparative Example 2] Comparative Composition 2

A composition 2 was obtained in the same manner as in Example 1, except that the component (A) of Example 1 was not used and the usage-amount of component (B) was changed to 100.0 parts. The external appearance observation of the release sheet obtained in this way, and evaluation of the peeling force and the residual adhesive rate were performed, and these are shown in Table 1.

[Comparative Example 3] Comparative Composition 3

As component (A) of composition 1 of Example 1, (a-2) 66.7 parts of polydimethylsiloxane (plasticity 1.50, vinyl content 0.75 mass %) having both ends of the molecular chain blocked with vinyl groups and having a vinyl group in the side chain was used Except that, Comparative Composition 3 was obtained in the same manner as in Example 1. The external appearance observation of the release sheet obtained in this way, and evaluation of the peeling force and the residual adhesive rate were performed, and these are shown in Table 1.

[Comparative Example 4] Comparative Composition 4

Comparative composition 4 was obtained like Example 1 except having changed the usage-amount of (A) component of the comparative composition 3 of Comparative Example 3 into 50.0 parts and the usage-amount of (B) component into 50.0 parts. The external appearance observation of the release sheet obtained in this way, and evaluation of the peeling force and the residual adhesive rate were performed, and these are shown in Table 1.

[Comparative Example 5] Comparative Composition 5

Comparative composition 5 was obtained like Example 1 except having changed the usage-amount of (A) component of the comparative composition 3 of Comparative Example 3 into 33.3 parts, and the usage-amount of (B) component into 66.7 parts. The external appearance observation of the release sheet obtained in this way, and evaluation of the peeling force and the residual adhesive rate were performed, and these are shown in Table 1.

[Comparative Example 6] Comparative composition 6

As the component (B) of the composition 1 of Example 1, (b-2) polydimethylsiloxane having both ends of the molecular chain blocked with hexenyl groups and having a hexenyl group on the side chain (viscosity 400 mPa·s, vinyl in hexenyl groups) A comparative composition 6 was obtained in the same manner as in Example 1, except that 33.3 parts of (CH ₂ =CH-) moiety content 0.97 mass%) was used. The external appearance observation of the release sheet obtained in this way, and evaluation of the peeling force and the residual adhesive rate were performed, and these are shown in Table 1.

[Comparative Example 7] Comparative Composition 7

Comparative composition 7 was obtained like Example 1 except having changed the usage-amount of (A) component of the comparative composition 6 of Comparative Example 6 into 50.0 parts, and the usage-amount of (B) component into 50.0 parts. The external appearance observation of the release sheet obtained in this way, and evaluation of the peeling force and the residual adhesive rate were performed, and these are shown in Table 1.

[Comparative Example 8] Comparative Composition 8

Comparative composition 8 was obtained like Example 1 except having changed the usage-amount of (A) component of the comparative composition 6 of Comparative Example 6 into 33.3 parts and the usage-amount of (B) component into 66.7 parts. The external appearance observation of the release sheet obtained in this way, and evaluation of the peeling force and the residual adhesive rate were performed, and these are shown in Table 1.

[Comparative Example 9] Comparative Composition 9

As component (A) of Comparative Composition 1 of Comparative Example 1, (a-2) 66.7 parts of polydimethylsiloxane (plasticity 1.50, vinyl content 0.75 mass%) having both ends of the molecular chain blocked with vinyl groups and having a vinyl group in the side chain Except using, it carried out similarly to the comparison 1, and obtained the comparative composition 9. Appearance observation of the release sheet thus obtained and evaluation of peel force and residual adhesive rate were performed, and these are shown in Table 1.

[Comparative Example 10] Comparative composition 10

As component (A) of Comparative Composition 1 of Comparative Example 1, (a-3) polydimethylsiloxane having both ends of the molecular chain blocked with methyl groups and having a vinyl group in the side chain (plasticity 1.50, vinyl content 0.85 mass%) was used Except that, Comparative Composition 9 was obtained in the same manner as in Comparative 1. The external appearance observation of the release sheet thus obtained and the evaluation of the peel force and residual adhesive rate were performed, and these were shown in Table 1.

In Table 1, components (a-1) to (a-3), components (b-1), (b) in the case where component (A) is represented by formula (1) and component (B) by formula (3) It shows that the functional groups of the terminal and side chains of -2) are put together.

[Tue 6]

[Tue 7]

As is clear from the results shown in Table 1, the release sheets obtained by curing the compositions (Examples 1 to 3) using a combination in which the component (A) and the component (B) both have an alkenyl group only in the side chain have excellent appearance and at the same time , the peel resistance value with respect to the adhesive substance was low, and also the residual adhesive rate was a favorable result. On the other hand, the comparative experiment is a case where the components (A) and (B) of the present invention are not used in combination, or an organopolysiloxane having an alkenyl group in addition to the side chain is used as a raw material, Comparative Compositions 1, 3 to 10 (Comparative Examples 1 and In 3-10), the peeling resistance with respect to the adhesive substance of the peeling layer obtained was high, and it was a result which could not implement|achieve favorable peeling characteristics. In addition, in Comparative Composition 2 (Comparative Example 2) using only the component (B), it was difficult to uniformly coat the composition on the base film, resulting in poor appearance of the release sheet, and no practical coatability could be realized.

Claims (10)

(A) a chain organopolysiloxane having a viscosity at 25° C. of 1,000,000 mPa·s or more in a liquid phase to a gum shape having plasticity at 25° C. and having an alkenyl group having 2 to 12 carbon atoms only in the side chain of the molecule;
(B) a chain organopolysiloxane having a viscosity at 25°C of 1,000 mPa·s or less and having an alkenyl group having 2 to 12 carbon atoms only in the side chain of the molecule;
(C) an organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms (Si-H) in one molecule, and
(D) hydrosilylation reaction catalyst
It is made by containing
The curable organopolysiloxane composition, wherein the mass ratio {(A)/(B)} of the component (A) to the component (B) is in the range of 95/5 to 5/95. The curable organopolysiloxane composition according to claim 1, wherein the mass ratio {(A)/(B)} of component (A) and component (B) is in the range of 90/10 to 10/90. The component (A) and the component (B) according to claim 1 or 2, wherein the component (A) and the component (B) have an alkenyl group having 4 to 12 carbon atoms only in the side chain of the molecule, and a vinyl (CH ₂ =CH-) moiety in the alkenyl group. The curable organopolysiloxane composition, wherein the content is 0.5 to 3.0 mass%, and the molecular chain terminal is a linear organopolysiloxane blocked with a trialkylsilyl group. The curable organopolysiloxane composition according to any one of claims 1 to 3, further comprising (E) an organic solvent. The curable organopolysiloxane composition according to any one of claims 1 to 4, further comprising (F) a hydrosilylation reaction inhibitor. The curable organopolysiloxane composition according to any one of claims 1 to 5, further comprising (G) a photopolymerization initiator. 7. The method according to any one of claims 1 to 6, wherein the mass ratio {(A)/(B)} of component (A) and component (B) is in the range of 70/30 to 30/70,
The curable organopolysiloxane composition, wherein the molar ratio of SiH groups in component (C) to the total number of moles of alkenyl groups in component (A) and component (B) is 0.5 to 5. A release coating agent comprising the curable organopolysiloxane composition according to any one of claims 1 to 7. A sheet-like article comprising a cured layer formed by curing the curable organopolysiloxane composition according to any one of claims 1 to 7 and a sheet-like substrate. A laminate having a structure in which an adhesive layer is disposed opposite to at least one release layer, wherein the release layer is a release layer made of a cured product obtained by curing the release coating agent according to claim 8.