JP6400430B2 - Curable composition for silicone coating layer and silicone coating sheet - Google Patents

Description

  The present invention relates to a silicone-coated sheet that can be used as, for example, a release sheet and a curable composition that can be used to form a silicone-coated layer in the silicone-coated sheet.

  Conventionally, a release sheet has been used to protect the adhesive layer of the adhesive sheet or to form a thin film member such as a ceramic green sheet. This release sheet is generally composed of a base material and a release agent layer provided on one surface of the base material.

  As a release agent constituting the release agent layer, a silicone release agent is mainly used. Silicone release agents can be broadly classified into thermosetting type and ultraviolet curable type, and UV curable type silicone release agents do not require a heating process for curing. Material can be used.

  Examples of the ultraviolet curable silicone release agent include a radical polymerization type and a cationic polymerization type. Among these, the cationic polymerization type silicone release agent has an advantage that it does not need to be cured in an inert gas atmosphere such as nitrogen gas because it is not inhibited by oxygen even when cured in air. As a release sheet using a cationic curable silicone resin for the release agent layer, for example, those described in Patent Documents 1 and 2 are known.

Japanese Patent No. 4946640 Japanese Patent No. 5401844

  However, in a release sheet that uses a conventional cationic curable silicone resin for the release agent layer, the release agent layer has insufficient adhesion to the substrate, and the release agent layer falls off the substrate due to rubbing, wet heat conditions, etc. There was a problem that.

  The present invention has been made in view of such a situation, and provides a cation-curable curable composition for a silicone coat layer and a silicone coat sheet that are excellent in adhesion of the silicone coat layer to a substrate. Objective.

  In order to achieve the above object, first, the present invention includes a silicone resin (A), a siloxane compound (B), and a photocationic catalyst (C), and at least the siloxane compound (B) is a cation. Provided is a curable composition for a silicone coat layer which is curable and has a cyclic siloxane skeleton (Invention 1).

  The silicone coat layer formed by curing the curable composition for a silicone coat layer according to the above invention (Invention 1) has good releasability, particularly due to the action of the siloxane compound (B) which is cationically curable and has a cyclic siloxane skeleton. As shown, the adhesion to the substrate is high.

  In the said invention (invention 1), it is preferable that the said siloxane compound (B) is a compound containing the cation reactive group which consists of an alicyclic epoxy group or a glycidyl group (invention 2).

（式中、Ｒ^１はアルキル鎖である。）
で示される構造を有することが好ましい（発明３）。 In the above inventions (Inventions 1 and 2), the siloxane compound (B) is represented by the following formula (b1)

(Wherein R ¹ is an alkyl chain.)
It is preferable to have the structure shown by (Invention 3).

（式中、Ｒ^２はアルキル基である。）
で示される化合物であることが好ましい（発明４）。 In the said invention (invention 1-3), the said siloxane compound (B) is a following formula (b2).

(In the formula, R ² is an alkyl group.)
It is preferable that it is a compound shown by (invention 4).

  In the said invention (invention 1-4), it is preferable that the said silicone resin (A) has a cation reactive group (invention 5).

（式中、Ｘ^１はカチオン反応性基を含む基であり、Ｒ^３、Ｒ^４及びＲ^５は互いに同一の又は異なるアルキル基、芳香族基又はアラルキル基である。また、ｎは１以上の整数であり、ｍは０又は１以上の整数である。）
で示されることが好ましい（発明６）。 In the said invention (invention 1-5), the said silicone resin (A) is a following formula (a1)

(In the formula, X ¹ is a group containing a cation-reactive group, and R ³ , R ⁴ and R ⁵ are the same or different alkyl groups, aromatic groups or aralkyl groups, and n is 1 or more. (It is an integer, and m is an integer of 0 or 1 or more.)
(Invention 6)

（式中、Ｒ^６はアルキル鎖である。）
で示されることが好ましい（発明７）。 Above in the invention (invention 6), ^{X 1} in the formula (a1) in the following formulas (a2)

(Wherein R ⁶ is an alkyl chain.)
(Invention 7)

In the above inventions (Inventions 6 and 7), the ratio between the proton amount of X ¹ in the silicone resin (A) represented by the formula (a1) and the total proton amount of R ³ , R ⁴ and R ⁵ is The integral ratio measured by NMR is preferably 1:20 to 1: 100 (Invention 8).

  In the said invention (invention 1-8), it is preferable that content of the said siloxane compound (B) with respect to 100 mass parts of said silicone resins (A) is 1-80 mass parts (invention 9).

  In the said invention (invention 5-8), it is preferable that the cation reactive group which the said silicone resin (A) has, and the cation reactive group which the said siloxane compound (B) have are the same functional groups (invention). 10).

  In the said invention (invention 1-10), it is preferable that the said photocationic catalyst (C) is an onium salt compound (invention 11).

  2ndly this invention is a silicone coat sheet provided with the sheet-like base material and the silicone coat layer provided in the at least one surface of the said base material, Comprising: The said silicone coat layer is the said silicone coat layer. A silicone-coated sheet obtained by curing a curable composition for use (Invention 1 to 11) is provided (Invention 12).

  In the said invention (invention 12), it is preferable that the said base material consists of a polyethylene terephthalate film (invention 13).

  In the said invention (invention 12 and 13), it is preferable to use in order to protect the surface of the thin film material selected from an adhesive material, a green sheet, and a resin film, or to form the said thin film material (invention 14). ).

  According to the present invention, it is possible to obtain a silicone-coated sheet having good peelability and excellent adhesion to the base material of the silicone-coated layer.

Hereinafter, embodiments of the present invention will be described.
[Curable composition for silicone coating layer]
The curable composition for a silicone coat layer according to the present embodiment (hereinafter sometimes simply referred to as “curable composition”) includes a silicone resin (A), a siloxane compound (B), and a photocationic catalyst (C ) And. At least the siloxane compound (B) is cationically curable and has a cyclic siloxane skeleton. The siloxane compound (B) does not include the silicone resin (A).

  The silicone coat layer obtained by curing the curable composition is particularly cationically curable and exhibits good releasability by the action of the siloxane compound (B) having a cyclic siloxane skeleton, and has high adhesion to the substrate. It becomes.

（式中、Ｘ^１は任意の官能基であり、特にカチオン反応性基を含む基が好ましく、Ｒ^３、Ｒ^４及びＲ^５は互いに同一の又は異なるアルキル基、芳香族基又はアラルキル基である。また、ｎは１以上の整数であり、ｍは０又は１以上の整数である。）
で示されるものであることが好ましい。 (1) Silicone resin (A)
The silicone resin (A) is a polymer (polyorganosiloxane) of a silicon-containing compound. The main skeleton of the silicone resin (A) is not particularly limited as long as it has a polysiloxane bond, but for example, the following formula (a1)

(In the formula, X ¹ is an arbitrary functional group, particularly preferably a group containing a cation reactive group, and R ³ , R ⁴ and R ⁵ are the same or different alkyl group, aromatic group or aralkyl group. N is an integer of 1 or more, and m is 0 or an integer of 1 or more.)
It is preferable that it is shown by these.

R ³ , R ⁴ and R ⁵ in the above formula (a1) preferably have 1 to 6 carbon atoms as alkyl groups, more preferably methyl, ethyl, propyl, isopropyl and the like. A methyl group is particularly preferred. In R ³ , R ⁴ and R ⁵ in formula (a1), the aromatic group is preferably a phenyl group, tolyl group, naphthyl group or the like, and the aralkyl group is preferably a benzyl group.

In the formula (a1), if R ³ , R ⁴ and R ⁵ are methyl groups, the surface of the silicone coat layer can be imparted with light release properties, so the resulting silicone coat sheet is a release sheet for pressure-sensitive adhesive materials. Or as a process sheet for a ceramic green sheet or a resin film.

  The silicone resin (A) may not have a functional group (in the formula (a1), when m is 0 and there is no functional group at the end of the main skeleton), it has a functional group. It may be. When it has a functional group, it may have in the side chain of the main skeleton as in the formula (a1), or may have at the end of the main skeleton.

The type of the functional group X ^1, not particularly limited, for example, alkenyl groups such as vinyl and hexenyl groups, hydrosilyl group, other (meth) acryloyl group, cationic reactive group. When the silicone resin (A) has a cation reactive group, the silicone resin (A) reacts with the cation curable siloxane compound (B) by irradiation with light (ultraviolet rays), and the resulting silicone coat layer adheres to the substrate. The sex becomes higher. Further, even if the curable composition is cured in the air, it is not necessary to cure in an inert gas atmosphere such as nitrogen gas because there is no inhibition of curing by oxygen. From this viewpoint, the silicone resin (A) preferably has a cation reactive group.

  Examples of the cation reactive group include an epoxy group and an oxetanyl group. Among these, from the viewpoint of reactivity, an epoxy group is preferable, an alicyclic epoxy group and a glycidyl group are particularly preferable, and a 3,4-epoxycyclohexyl group is more preferable.

（式中、Ｒ^６はアルキル鎖である。）
で示されるものであることが好ましい。Ｘ^１がかかる構造を有することにより、シロキサン化合物（Ｂ）と同じカチオン重合反応を起こすことができるため、化合物間の結合を生じさせて、シリコーンコート層の硬度を高め、基材とシリコーンコート層との密着性をより向上させることができる。 X ¹ in the above formula (a1) is the following formula (a2)

(Wherein R ⁶ is an alkyl chain.)
It is preferable that it is shown by these. Since X ¹ has such a structure, it can cause the same cationic polymerization reaction as that of the siloxane compound (B), so that a bond between the compounds is generated and the hardness of the silicone coat layer is increased. Can be further improved.

The alkyl chain of R ^{6 in} the above formula (a2) preferably has 1 to 6 carbon atoms, particularly preferably 1 to 2 carbon atoms.

  N in the formula (a1) is preferably 2 to 600. Moreover, it is preferable that m in the said Formula (a1) is 0-3000. Further, the relationship between n and m is preferably n + m = 30 to 1000, and preferably n / (n + m) = 0.01 to 0.5.

On the other hand, the ratio of the proton amount of X ¹ in the silicone resin (A) represented by the formula (a1) to the total proton amount of R ³ , R ⁴ and R ⁵ is an integral ratio measured by NMR: The ratio is preferably 5 to 1: 100, particularly preferably 1:20 to 1: 100, and more preferably 1:20 to 1:50. In addition, the measuring method of the proton amount by NMR is as showing in the test example mentioned later.

The ratio of the proton amount of X ^{1 to} the total proton amount of R ³ , R ⁴ and R ⁵ , or n, m and their relationship are within the above ranges, whereby the silicone resin (A) and the cationic curable property The balance between the adhesiveness of the silicone coat layer to the substrate based on the reactivity with the siloxane compound (B) and the peelability can be kept good.

  The weight average molecular weight of the silicone resin (A) is preferably 1,000 to 500,000, particularly preferably 5,000 to 100,000, and more preferably 10,000 to 70,000. Is preferred. In addition, the weight average molecular weight in this specification is the value of polystyrene conversion measured by the gel permeation chromatography (GPC) method.

  When the weight average molecular weight of the silicone resin (A) is 1,000 or more, the coating viscosity of the curable composition according to the present embodiment can be prevented from becoming too low, and the occurrence of repelling is suppressed. A uniform silicone coating layer can be obtained. Further, when the weight average molecular weight of the silicone resin (A) is 100,000 or less, an increase in the coating viscosity of the curable composition according to this embodiment can be suppressed, and solubility in a diluting solvent can be ensured. .

(2) Siloxane compound (B)
The siloxane compound (B) is a compound that is cationically curable and has a cyclic siloxane skeleton. As described above, since the siloxane compound (B) does not include the silicone resin (A), both are present as separate components in the curable composition according to this embodiment. When the curable composition according to this embodiment contains the siloxane compound (B) in particular, the silicone coat layer formed by curing the curable composition exhibits good releasability and adheres to the substrate. It becomes a thing with high property. The high adhesion to the substrate is presumed to involve the polarity of the cyclic siloxane skeleton of the siloxane compound (B), but it is not always clear.

  The number of siloxane units (Si—O) constituting the cyclic siloxane skeleton is not particularly limited, but is preferably 4 (tetramer).

The siloxane compound (B) is preferably a compound containing a cation reactive group composed of an alicyclic epoxy group or a glycidyl group. Examples of the alicyclic epoxy group include 2,3-epoxycyclobutyl group, 2,3-epoxycyclopentyl group, 3,4-epoxycyclohexyl group, 5,6-epoxy-tricyclo [5,2,1,0]. ^2,6] decan-8-yl group, 2,3-epoxy - tricyclo [4,2,1,0 ^2,5] nonane-7-yl group, 3- (3,4-epoxycyclohexyl) -9- Hydroxy-1,5-dioxaspiro [5,5] undecan-8-yl group, 3- (3,4-epoxycyclohexyl) -9-hydroxy-2,4-dioxaspiro [5,5] undecan-8-yl group Etc. Among the above, the siloxane compound (B) preferably contains a 3,4-epoxycyclohexyl group. These cationic reactive groups are excellent in reactivity and can increase the hardness of the silicone coat layer.

（式中、Ｒ^１はアルキル鎖である。）
で示される構造を有することが好ましい。 The cation reactive group is preferably bonded directly or indirectly to the silicon atom of the cyclic siloxane skeleton. Specifically, the siloxane compound (B) is represented by the following formula (b1)

(Wherein R ¹ is an alkyl chain.)
It is preferable to have the structure shown by these.

The alkyl chain of R ^{1 in} the above formula (b1) preferably has 1 to 6 carbon atoms, particularly preferably 1 to 2 carbon atoms.

（式中、Ｒ^２はアルキル基である。）
で示される化合物であることが好ましい。式（ｂ２）で示されるシロキサン化合物（Ｂ）は、剥離性に悪影響を与えることなく、基材に対するシリコーンコート層の密着性を向上させる効果に特に優れる。上記式（ｂ２）中のＲ^２は、メチル基またはエチル基が好ましい。 The siloxane compound (B) has the following formula (b2)

(In the formula, R ² is an alkyl group.)
It is preferable that it is a compound shown by these. The siloxane compound (B) represented by the formula (b2) is particularly excellent in the effect of improving the adhesion of the silicone coat layer to the substrate without adversely affecting the peelability. R ² in the above formula (b2) is preferably a methyl group or an ethyl group.

  Here, it is preferable that the cation reactive group which a silicone resin (A) has, and the cation reactive group which a siloxane compound (B) has are the same functional groups, and especially the same alicyclic epoxy group or glycidyl. It is preferably a group, and more preferably both are 3,4-epoxycyclohexyl groups. Thereby, since both reaction systems become the same, the silicone resin (A) and the siloxane compound (B) can be directly chemically bonded, the hardness of the resulting silicone coat layer is improved, and the adhesion to the substrate is improved. The sex becomes higher.

  In the curable composition which concerns on this embodiment, it is preferable that content of the siloxane compound (B) with respect to 100 mass parts of silicone resins (A) is 1-80 mass parts, and it is especially 5-30 mass parts. Is more preferable, and it is preferable that it is 7-15 mass parts. When the content of the siloxane compound (B) with respect to 100 parts by mass of the silicone resin (A) is 1 part by mass or more, the effect of the siloxane compound (B) is satisfactorily exhibited, and the resulting silicone coat layer adheres to the substrate. Increases nature. Moreover, when the content of the siloxane compound (B) is 100 parts by mass or less with respect to 100 parts by mass of the silicone resin (A), the amount of the silicone resin (A) is secured and the peelability of the resulting silicone coat layer is good. Can be made.

(3) Photocationic catalyst (C)
Since the cationic photocatalyst (C) generates cationic species upon irradiation with light (ultraviolet rays), the cationic polymerization reaction of the siloxane compound (B) and the silicone resin (A) (when it has a cationic reactive group) can proceed. .

  Examples of the photocation catalyst (C) include onium salts such as iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, ammonium salts, and pyridinium salts; metallocene compounds such as iron arene complexes; β-ketoesters, β-sulfonylsulfones And sulfone compounds such as α-diazo compounds; sulfonic acid esters such as alkyl sulfonates, haloalkyl sulfonates, aryl sulfonates, and imino sulfonates; sulfonimide compounds, diazomethane compounds, and the like. Species can be used alone or in combination of two or more.

  Among these, onium salts such as iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, ammonium salts, and pyridinium salts are preferable, and iodonium salts are particularly preferable. Since these cation species are likely to be generated by irradiation with light (ultraviolet rays), the cationic polymerization reaction of the siloxane compound (B) and the silicone resin (A) (when having a cation reactive group) efficiently proceeds, and good releasability. And the silicone coat layer which has base-material adhesiveness is formed.

  The content of the photocationic catalyst (C) in the curable composition according to this embodiment is 1 with respect to 100 parts by mass of the total amount of the siloxane compound (B) and the silicone resin (A) having a cation reactive group. It is preferably 10 to 10 parts by mass, particularly preferably 2 to 7 parts by mass, and further preferably 3 to 5 parts by mass.

(4) Other components In addition to the above components, the release agent composition according to the present embodiment includes, for example, a silane coupling agent, a reaction inhibitor, an adhesion improver, a crosslinking agent, a catalyst, a photoinitiator, an antistatic agent, You may contain antioxidant, a coloring agent, a filler, etc. When the silane coupling agent is contained, the adhesion between the silicone coat layer and the substrate can be further improved.

  As the silane coupling agent, a silane compound having an organic group having a functional group and an alkoxy group having hydrolyzability is preferable, and is different from a siloxane compound (B) having no hydrolyzable group. Examples of such silane coupling agents include polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2 -Mercapto group-containing silicon compounds having an epoxy structure such as (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyldimethoxymethylsilane Contains amino groups such as silicon compounds, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane Iodine compound, 3-chloropropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, or at least one of them, and alkyl groups such as methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane A condensate with a contained silicon compound, etc. are mentioned. Among the above, a silicon compound having an epoxy structure is preferable, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane is particularly preferable. These may be used individually by 1 type and may be used in combination of 2 or more type.

  When the release agent composition according to the present embodiment contains a silane coupling agent, the content is preferably 0.1 to 50 parts by mass with respect to 100 parts by mass of the silicone resin (A), in particular. It is preferably 1 to 30 parts by mass, more preferably 5 to 20 parts by mass.

Further, the functional group X ¹ of the silicone resin used in the present embodiment (A) is the case of the alkenyl group include the siloxane compound having a hydrosilyl group in the side chain or end as a crosslinking agent. Further, when the functional group X ¹ of the silicone resin used in the present embodiment (A) is an alkenyl group, a platinum-based catalyst is preferred as the catalyst.

[Silicone coated sheet]
The silicone coat sheet according to the present embodiment includes a sheet-like base material and a silicone coat layer provided on at least one surface of the base material.

(1) Use Although the use of the silicone coat sheet which concerns on this embodiment is not specifically limited, For example, in order to protect the surface of thin film materials, such as an adhesive material, a green sheet, a resin film, or to form the said thin film material into a film Can be preferably used. For example, it can also be used as a release sheet for protecting the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet, and can also be used as a release sheet for a green sheet manufacturing process for forming a green sheet (ceramic green sheet). Moreover, it can also be used as a process sheet for forming a polyvinyl chloride resin, a urethane resin or the like as a synthetic leather. Since the silicone coat sheet which concerns on this embodiment exhibits favorable peelability, it can be used conveniently as those release sheets.

  Moreover, the silicone coat sheet which concerns on this embodiment is not restricted to the use where a silicone coat layer is used in contact with thin film materials etc. like the said peeling sheet. For example, a silicone coat layer may be used by being exposed to the outside, such as a hard coat sheet or an antifouling sheet.

(2) Base material The base material of the silicone coat sheet according to the present embodiment is not particularly limited as long as the silicone coat layer can be laminated. Examples of the substrate include paper substrates such as glassine paper, coated paper, cast coated paper, dust-free paper, and high-quality paper; laminated paper obtained by laminating a thermoplastic resin such as polyethylene on these paper substrates; various plastic films Non-woven fabric; metal foil; or a laminated sheet containing these; Among these, particularly when the substrate is made of a plastic film, the effect of improving the substrate adhesion of the silicone coat layer according to the present embodiment is easily obtained.

  Examples of the plastic film include films made of polyester such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyolefins such as polyethylene and polypropylene, polycarbonate, vinyl acetate, and the like, and may be a single layer. However, it may be a multilayer of two or more layers of the same type or different types.

  Here, for example, when producing a ceramic green sheet using the silicone-coated sheet according to the present embodiment, among the plastic films, a polyester film is preferable, a polyethylene terephthalate film is particularly preferable, and biaxial stretching is further performed. A polyethylene terephthalate film is preferred. Since the polyethylene terephthalate film hardly generates dust or the like during processing or use, for example, it is possible to effectively prevent a ceramic slurry coating failure due to dust or the like.

  In the above-mentioned base material, for the purpose of improving the adhesion with the silicone coat layer provided on the surface thereof, one or both surfaces can be subjected to surface treatment by an oxidation method or an unevenness method, or a primer treatment as desired. . Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, ultraviolet irradiation treatment, and the like. Examples include a thermal spraying method. These surface treatment methods are appropriately selected depending on the type of the base film, but generally, a corona discharge treatment method is preferably used from the viewpoints of effects and operability.

  Although the thickness of a base material should just be determined suitably according to the use of a silicone coat sheet, it is 10-300 micrometers normally, Preferably it is 15-200 micrometers, Especially preferably, it is 20-125 micrometers.

(3) Silicone Coat Layer The silicone coat layer of the silicone coat sheet according to this embodiment is formed by curing the above-described curable composition for a silicone coat layer.

  The thickness of the silicone coat layer may be appropriately determined according to the use of the silicone coat sheet, but is usually preferably 0.01 to 20 μm, particularly preferably 0.03 to 1 μm, It is preferable that it is 0.03-1 micrometer. When the thickness of the silicone coat layer is 0.01 μm or more, the peelability can be stably exhibited when the silicone coat sheet is used as a release sheet. On the other hand, if the thickness of the silicone coat layer is 20 μm or less, curling of the silicone coat sheet due to curing of the silicone coat layer can be suppressed.

(4) Silicone Coated Sheet Manufacturing Method The silicone coated sheet according to the present embodiment is coated with the above-described curable composition for a silicone coated layer and, if desired, a coating liquid containing an organic solvent on one surface of a substrate. After being processed, it is obtained by drying and curing by light (ultraviolet) irradiation to form a silicone coat layer. As the coating method, for example, gravure coating method, bar coating method, spray coating method, spin coating method, knife coating method, roll coating method, die coating method and the like can be used.

  There is no restriction | limiting in particular as said organic solvent, A various thing can be used. For example, hydrocarbon compounds such as toluene, hexane, heptane, acetone, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and mixtures thereof are used.

  Although it does not specifically limit as an ultraviolet irradiation apparatus used for ultraviolet irradiation, For example, an electrodeless lamp, a high pressure mercury lamp, a metal halide lamp, a UV-LED lamp, a black light etc. are mentioned.

Illuminance of ultraviolet rays is preferably 1~3000mW / cm ^2, particularly preferably 200~2000mW / cm ^2, preferably further is 800~1800mW / cm ^2. Further, the amount of ultraviolet light is preferably 10~1000mJ / cm ^2, particularly preferably 20~600mJ / cm ^2, preferably further is 100~300mJ / cm ^2. When the illuminance and light quantity of the ultraviolet rays are within the above ranges, the curable composition is cured well, the resulting silicone coat layer exhibits good releasability, and the adhesion to the substrate is enhanced.

(5) Physical properties (5-1) Adhesiveness of silicone coat layer to substrate In the silicone coated sheet according to this embodiment, the adhesiveness of the silicone coat layer to the substrate is excellent. Specifically, as shown in a test example to be described later, the silicone coat layer is not easily detached from the base material by the rub-off test even after the wet heat environment (40 ° C./80% RH) is promoted. In addition, even when the Gakushin test was performed as shown in the test examples described later, the adhesion of the silicone coat layer to the substrate (%) (= (peeling force of the polished portion / peeling force of the unpolished portion) × 100) Is high, preferably 115% or less, particularly preferably 110% or less, more preferably 105% or less. The adhesion when the Gakushin test in this specification is performed is the rate of change in the peel strength of the silicone coat layer before and after the Gakushin test, which is caused by the dropout of the silicone coat layer caused by the Gakushin test. Say. The closer the adhesion value is to 100%, the less the silicone coat layer falls off, and the better the adhesion between the silicone coat layer and the substrate.

(5-2) Peeling force The silicone coating layer formed by curing the curable composition for a silicone coating layer according to the present embodiment preferably contains a silicone resin (A) by containing the siloxane compound (B). By being a cationic polymerization type silicone resin, the elastic modulus is increased, and thereby excellent light release properties are obtained.

  Specifically, the peel strength of the silicone-coated sheet according to this embodiment with respect to the acrylic adhesive tape is preferably 20 to 400 mN / 20 mm, particularly preferably 30 to 200 mN / 20 mm, and more preferably 40 to 130 mN / 20 mm. Can be achieved. Moreover, the peeling force with respect to the polyvinyl butyral (PVB) film of the silicone-coated sheet according to this embodiment is preferably 5 to 70 mN / 20 mm, particularly preferably 10 to 60 mN / 20 mm, and more preferably 20 to 40 mN / 20 mm. Can be achieved.

  In addition, the measuring method of the said peeling force is as showing to the test example mentioned later. When the peeling force is in the above range, the thin film material (for example, an adhesive layer, a ceramic green sheet, etc.) laminated on the silicone coat layer of the silicone coat sheet according to the present embodiment and the silicone coat sheet are peeled off. It is possible to reduce the peeling failure.

(5-3) Silicone transfer amount The silicone coat layer formed by curing the curable composition for a silicone coat layer according to the present embodiment preferably contains a siloxane compound (B), and more preferably a silicone resin (A). Is a cationic polymerization type silicone resin, the amount of silicone transferred to a material laminated on the silicone coat layer, such as an adhesive layer or a ceramic green sheet, is small.

  Specifically, after forming the acrylic pressure-sensitive adhesive layer on the surface of the silicone coat layer, the acrylic pressure-sensitive adhesive layer is in contact with the silicone coat layer in the acrylic pressure-sensitive adhesive layer when the acrylic pressure-sensitive adhesive layer is peeled off from the silicone coat layer. The amount of silicone transferred on the back surface (adhesive surface) is small. The amount of silicone transferred is preferably 80 cps or less, particularly preferably 60 cps or less, and more preferably 40 cps or less, as measured by silicon atoms measured by X-ray fluorescence analysis (XRF).

  In addition, since the acrylic pressure-sensitive adhesive layer itself is at a level where silicon is not detected by XRF, the silicon atomic ratio can be used as an evaluation standard for the migration amount of the silicone-based compound from the silicone coat layer. it can.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, another layer such as an antistatic layer may be provided between the surface of the substrate opposite to the silicone coat layer and between the substrate and the silicone coat layer.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Examples 1 to 21]
As the silicone resin (A), a 3,4-epoxycyclohexyl group-containing organopolysiloxane having the structures of the above-described formulas (a1) and (a2), wherein R ³ , R ⁴ and R ⁵ are CH ₃ ( Arakawa Chemical Industries, trade name “POLY-200”, trade name “POLY-201”, and trade name “POLY-215”) were prepared.

When the above-mentioned “POLY-200”, “POLY-201” and “POLY-215” were subjected to NMR measurement using a nuclear magnetic resonance apparatus (manufactured by BRUKER, NMR Fourier 300), the proton amount of each organopolysiloxane was measured. The ratio (the amount of protons of X ¹ : the total amount of protons of R ³ , R ⁴ and R ⁵ ) was as follows.
"POLY-200" ... 1:38
"POLY-201" ... 1:39
"POLY-215" ... 1:26

Moreover, when the weight average molecular weight of the above-mentioned “POLY-200”, “POLY-201” and “POLY-215” was measured using a GPC apparatus (trade name “HLC-8320GPC” manufactured by Tosoh Corporation), It was street.
"POLY-200" ... 15,000
"POLY-201" ... 50,000
"POLY-215" ... 15,700

  As the silicone resin (A), the 3,4-epoxycyclohexyl group-containing organopolysiloxane (manufactured by Arakawa Chemical Industries, trade name “POLY-200” (Examples 1 to 7), trade name “POLY-201” (implemented) Examples 8 to 14), or trade name “POLY-215” (Examples 15 to 21)) were diluted with isopropyl alcohol (IPA) solvent so that the solid content concentration was 3.0 mass%.

In the above solution, a 3,4-epoxycyclohexyl group-containing silane oligomer (made by Shin-Etsu Chemical Co., Ltd., trade name “X40-2670” as the siloxane compound (B), the formula (b2) (R ² is CH ₃ ) described above. As shown in Table 1, 1 to 60 parts by mass was added to 100 parts by mass of the silicone resin (A) (in terms of solid content; the same applies hereinafter). Thereafter, to this solution, an onium salt photoinitiator (a salt of diphenyliodonium and tetra (pentafluorophenyl) borate anion; trade name “CATA-211” manufactured by Arakawa Chemical Industries, Ltd.) as a photocationic catalyst (C) Was added to obtain a solution (coating solution) of the curable composition for the silicone coat layer.

The coating solution of the obtained release agent composition is uniformly applied to a biaxially stretched polyethylene terephthalate film (made by Mitsubishi Plastics, trade name “Diafoil T100-38”, thickness 38 μm) as a substrate by a bar coater. Applied. Next, after heating and drying at 80 ° C. for 30 seconds, the release agent composition is cured by ultraviolet irradiation (light quantity 60 mJ / m ² , illuminance 1500 mW / cm ² ), and a 0.2 μm thick silicone coat layer is formed on the substrate. A laminated silicone coat sheet was obtained.

[Example 22]
3,4-epoxycyclohexyl group-containing organopolysiloxane (trade name “POLY-201”, manufactured by Arakawa Chemical Industries, Ltd.) as a silicone resin (A) in an isopropyl alcohol (IPA) solvent has a solid content concentration of 3.0 mass. Diluted to%.

In the above solution, a 3,4-epoxycyclohexyl group-containing silane oligomer (made by Shin-Etsu Chemical Co., Ltd., trade name “X40-2670” as the siloxane compound (B), the formula (b2) (R ² is CH ₃ ) described above. 10 parts by mass was added to 100 parts by mass of the silicone resin (A).

  Next, 10 parts by mass of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KBM303”) as a silane coupling agent was added to the above solution. Thereafter, to this solution, an onium salt photoinitiator (a salt of diphenyliodonium and tetra (pentafluorophenyl) borate anion; trade name “CATA-211” manufactured by Arakawa Chemical Industries, Ltd.) as a photocationic catalyst (C) Was added to obtain a solution (coating solution) of the curable composition for the silicone coat layer.

  A silicone-coated sheet was produced in the same manner as in Example 1 using the obtained coating solution of the release agent composition.

[Comparative Examples 1-3]
3,4-epoxycyclohexyl group-containing organopolysiloxane as silicone resin (A) (Arakawa Chemical Industries, trade name “POLY-200” (Comparative Example 1), trade name “POLY-201” (Comparative Example 2)) Alternatively, the product name “POLY-215” (Comparative Example 3)) was diluted with isopropyl alcohol (IPA) solvent so that the solid content concentration was 3.0 mass%. To this solution was added an onium salt photoinitiator (a salt of diphenyliodonium and tetra (pentafluorophenyl) borate anion; trade name “CATA-211” manufactured by Arakawa Chemical Industries, Ltd.) as a photocationic catalyst (C). 0.0 part by mass was added to obtain a solution (coating solution) of the curable composition for the silicone coat layer.

  A silicone-coated sheet was produced in the same manner as in Example 1 using the obtained coating solution of the release agent composition.

[Comparative Examples 4 to 5]
3,4-epoxycyclohexyl group-containing organopolysiloxane (trade name “POLY-201”, manufactured by Arakawa Chemical Industries, Ltd.) as a silicone resin (A) in an isopropyl alcohol (IPA) solvent has a solid content concentration of 3.0 mass. Diluted to%.

  Next, 10 parts by mass (Comparative Example 4) or 30 parts of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KBM303”) as a silane coupling agent is added to the above solution. Part by mass (Comparative Example 5) was added. Thereafter, to this solution, an onium salt photoinitiator (a salt of diphenyliodonium and tetra (pentafluorophenyl) borate anion; trade name “CATA-211” manufactured by Arakawa Chemical Industries, Ltd.) as a photocationic catalyst (C) Was added to obtain a solution (coating solution) of the curable composition for the silicone coat layer.

  A silicone-coated sheet was produced in the same manner as in Example 1 using the obtained coating solution of the release agent composition.

[Test Example 1] (Love-off test)
The silicone-coated sheets obtained in Examples and Comparative Examples were left for 1 to 7 days in an atmosphere of 40 ° C. and 80% RH. Immediately after the production of the silicone-coated sheet, the silicone-coated layer is rubbed with a finger at each stage after being left in the above atmosphere for 1 day, after being left for 3 days, and after being left for 7 days, and the presence or absence of the silicone-coated layer from the base material is observed. did. The results are shown in Table 1.
○: No dropout ×: Dropout

[Test Example 2] (Gakushin Examination)
About the silicone coat sheet obtained by the Example and the comparative example, using a Gakushin Tester (made by Daiei Kagaku Seiki Seisakusho Co., Ltd., trade name “RT-200”), the silicone coat sheet surface of the silicone coat sheet was used. The unstretched polypropylene film was pressure-welded with a load of 200 g and polished 10 times. Thereafter, an acrylic adhesive tape (manufactured by Nitto Denko Corporation, 31B tape) was attached to each of the polished part and the unpolished part with a 2 kg roller.

After curing for 30 minutes under conditions of 23 ° C. and 50% RH, the acrylic adhesive tape was peeled off at an angle of 180 ° and a peeling speed of 100 m / min using a tensile tester (Orientec, Tensilon). The force (peeling force; mN / 20 mm) required for the measurement was measured. And adhesiveness (%) was computed based on the following formula | equation from the peeling force of a grinding | polishing part and the peeling force of an unpolished part. The results are shown in Table 1.
Adhesiveness (%) = (Peeling force of polished part / Peeling force of unpolished part) × 100

[Test Example 3] (Measurement of tape peeling force)
An acrylic adhesive tape (manufactured by Nitto Denko Corporation, 31B tape, 20 mm width) was attached to the surface of the silicone coat layer of the silicone coat sheet obtained in the examples and comparative examples with a 2 kg roller. After curing for 30 minutes under the conditions of 23 ° C. and 50% RH, the acrylic adhesive tape was peeled off at an angle of 180 ° and a peeling speed of 0.3 m / min using a tensile tester (Orientec, Tensilon). The force required for peeling (peeling force; mN / 20 mm) was measured (number of measurements n = 2). The results are shown in Table 1.

[Test Example 4] (Measurement of peel strength against PVB)
To 100 parts by mass of polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., trade name “S-LEC BL-S”; hereinafter referred to as “PVB”), 240 parts by mass of toluene and 160 parts by mass of ethanol are added as a mixed solvent, and stirred uniformly with a disper. It mixed and the PVB coating liquid was prepared. And the said PVB coating liquid was apply | coated using the applicator on the silicone coating layer of the silicone coating sheet obtained by the Example and the comparative example, and it dried and formed the PVB layer. In addition, the film thickness of the PVB layer after drying was 3 μm.

  Next, a laminate in which an adhesive tape (manufactured by Nitto Denko Corporation, trade name “31B tape”) is bonded to the surface of the PVB layer on the silicone-coated sheet is prepared, and the laminate is placed under an environment of 23 ° C. and 50% RH. Left for hours. Next, this laminate was cut into 40 mm × 100 mm to obtain a test piece for measuring the peel strength against PVB.

  In an environment of 23 ° C. and 50% RH, using a high speed peel tester (manufactured by Tester Sangyo Co., Ltd.), the silicone coat sheet of the test piece was peeled at a peel angle of 180 ° and a peel speed of 100 m / min to measure the peel force. . The maximum value (unit: mN / 20 mm) of the peel force in the measurement range at this time was defined as the PVB peel force.

[Test Example 5] (Measurement of silicone migration)
An acrylic pressure-sensitive adhesive (manufactured by Toyochem, product name “BPS5127”) is applied to the surface of the silicone coat layer of the silicone coat sheet obtained in the examples and comparative examples with an applicator so that the film thickness after drying becomes 30 μm. This was applied and dried by heating at 100 ° C. for 2 minutes to form an adhesive layer. A polyethylene terephthalate film (thickness: 50 μm) was bonded as an adhesive sheet substrate to the exposed surface of the adhesive layer, and stored for one day under conditions of 23 ° C. and 50% RH. Thereafter, the silicone-coated sheet is peeled off from the pressure-sensitive adhesive layer, and the amount of silicone (cps) on the surface of the pressure-sensitive adhesive layer (adhesive surface) is measured with a fluorescent X-ray apparatus (wavelength dispersion tabletop fluorescent X-ray analyzer; manufactured by Rigaku Corporation, product Name “Mini-Z”). The results are shown in Table 1.

  As is clear from Table 1, the silicone-coated sheets obtained in the examples are excellent in adhesion to the base material of the silicone-coated layer while exhibiting good peeling force, and have a small amount of silicone migration to the adhesive surface. It was.

  The curable composition for a silicone coat layer and the silicone coat sheet of the present invention can be suitably used, for example, as a release sheet for a pressure-sensitive adhesive sheet or a release sheet for a green sheet production process.

Claims (9)

Silicone resin (A);
A siloxane compound (B);
A photocationic catalyst (C),
At least the siloxane compound (B) is represented by the following formula (b2)

(In the formula, R ² is an alkyl group.)
In Ri compound der represented,
The curable composition for a silicone coat layer, wherein the content of the siloxane compound (B) with respect to 100 parts by mass of the silicone resin (A) is 1 to 80 parts by mass . The silicone resin (A), silicone coat layer curable composition according to claim 1, characterized in that it comprises a cationic reactive group. The silicone resin (A) has the following formula (a1)

(In the formula, X ¹ is a group containing a cation-reactive group, and R ³ , R ⁴ and R ⁵ are the same or different alkyl groups, aromatic groups or aralkyl groups, and n is 1 or more. (It is an integer, and m is an integer of 0 or 1 or more.)
Claim 1 or silicone coat layer curable composition according to 2, characterized in that those having a skeleton represented in. X ¹ in the formula (a1) represents the following formula (a2)

(Wherein R ⁶ is an alkyl chain.)
It is shown by these, The curable composition for silicone coat layers of Claim 3 characterized by the above-mentioned. The ratio of the proton amount of X ¹ in the silicone resin (A) represented by the formula (a1) to the total proton amount of R ³ , R ⁴ and R ⁵ is an integral ratio measured by NMR: 1: It is 20-1: 100, The curable composition for silicone coat layers of Claim 3 or 4 characterized by the above-mentioned. The said photocationic catalyst (C) is an onium salt compound, The curable composition for silicone coat layers as described in any one of Claims 1-5 characterized by the above-mentioned. A sheet-like substrate;
A silicone coat sheet provided with a silicone coat layer provided on at least one surface of the substrate,
The said silicone coat layer hardens | cures the curable composition for silicone coat layers as described in any one of Claims 1-6 , The silicone coat sheet characterized by the above-mentioned. The silicone-coated sheet according to claim 7 , wherein the substrate is made of a polyethylene terephthalate film. The silicone-coated sheet according to claim 7 or 8 , which is used for protecting a surface of a thin film material selected from an adhesive material, a green sheet, and a resin film, or for forming the thin film material.