JP4936013B2 - Solvent-free curable silicone release agent composition for plastic film and peelable plastic film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solvent-free curable silicone releasing agent composition yielding a cured product which shows good adhesion to a plastic film substrate and is excellent in release properties, and a releasable plastic film on which a cured film of the composition is formed. <P>SOLUTION: The solvent-free curable silicone releasing agent composition shows viscosity at 25&deg;C of 100-1,500 mPa s and comprises (A) a branched organopolysiloxane of formula (1): (R<SB>3</SB>SiO<SB>1/2</SB>)<SB>3</SB>(R<SP>1</SP>RSiO)<SB>a</SB>(R<SB>2</SB>SiO)<SB>X</SB>(RSiO<SB>3/2</SB>)<SB>1</SB>(wherein R<SP>1</SP>is an alkenyl group; R is a monovalent hydrocarbon group; and (a) and X satisfy the relations: 1.9&le;a&lt;3.8 and 40&le;X&le;450, respectively), (B) an organopolysiloxane of formula (2) (wherein R<SP>2</SP>is an alkenyl group; R is a monovalent hydrocarbon group; R<SP>3</SP>is H or an alkyl group; m and n are positive numbers; and p is 0 or a positive number, provided that m, n and p satisfy the relations: 0.6&le;(n+p)/m&le;1.5 and 0&le;p/(n+p)&le;0.05), (C) an organohydrogenpolysiloxane with a specific viscosity and (D) a platinum metal catalyst. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a solventless curable silicone release agent composition that gives a cured product having excellent adhesion to a plastic film, and a peelable plastic film suitable as a release film for an adhesive label or an adhesive tape using the same. Is.

  Conventionally, for the purpose of preventing adhesion or adhesion between a base material such as paper or plastic film and an adhesive substance, it is possible to form a cured film of the silicone composition on the surface of the base material to impart releasability. Has been done.

  In this case, as a method of forming a silicone film on the surface of the substrate, a method of forming a peelable film by addition reaction of an organopolysiloxane containing an alkenyl group and an organohydrogenpolysiloxane using a platinum compound as a catalyst. (See, for example, Japanese Patent Application Laid-Open No. 47-32072: Patent Document 1) is widely used.

In recent years, silicone release agents have been switched from a solvent type containing an organic solvent such as toluene or xylene to a solventless type containing no organic solvent from the viewpoint of safety and hygiene.
Various types of solvent-free silicone compositions are known (see, for example, JP-A-50-141591 and JP-A-52-39791: Patent Documents 2 and 3). However, although these compositions have good adhesion to paper substrates, they have a problem of poor adhesion to plastic film substrates.

  In order to solve the above problems, Japanese Patent Laid-Open Nos. 06-293881 and 2003-026925 (Patent Documents 4 and 5) are known. Although satisfactory adhesion to a film cannot be obtained, and JP-A No. 2003-026925, although adhesion is improved, peeling resistance with the pressure-sensitive adhesive layer is extremely large, that is, heavy peeling occurs. It was difficult to obtain peelability. In order to achieve both adhesion and peelability, Japanese Patent Application Laid-Open No. 2005-231355 (Patent Document 6) proposes a method comprising a two-layer coating. Absent.

Japanese Patent Laid-Open No. 47-32072 Japanese Patent Laid-Open No. 50-141591 Japanese Patent Laid-Open No. 52-39791 Japanese Patent Laid-Open No. 06-238881 Japanese Patent Laid-Open No. 2003-026925 JP 2005-231355 A

  The present invention has been made in view of the above circumstances, and is a solventless curable silicone release agent composition that gives a cured product having good adhesion to a plastic film substrate and excellent in peelability, and curing of this composition. It aims at providing the peelable plastic film in which a membrane | film | coat is formed.

In order to achieve the above object, the present inventor has conducted various studies on alkenyl group-containing organopolysiloxane as a main component of the silicone release agent composition. As a result, the present inventors have a branched structure and bonded to silicon atoms in the side chain of the molecule. By combining the diorganopolysiloxane having a specific amount of the higher alkenyl group and the alkenyl group-containing organopolysiloxane represented by the general composition formula (2), adhesion to the plastic film substrate and excellent adhesive layer are achieved. It has been found that a silicone release agent composition can be obtained that gives a cured product capable of satisfying both release properties.
It has been found that a peelable plastic film having a cured film of this composition formed on a plastic film substrate can be suitably used as a peelable film for pressure-sensitive adhesive labels and pressure-sensitive adhesive tapes, and has led to the present invention.

（式中、Ｒ²はアルケニル基、Ｒは脂肪族不飽和結合を含有しない同一又は異種の一価炭化水素基、Ｒ³は水素原子又は炭素数１〜８のアルキル基、ｍ，ｎは正数、ｐは０又は正数で、０．６≦（ｎ＋ｐ）／ｍ≦１．５、０≦ｐ／（ｎ＋ｐ）≦０．０５であり、かつ、ｍ，ｎ，ｐはこのオルガノポリシロキサンの２５℃における粘度を５〜１００ｍＰａ・ｓとする数である。）
（Ｃ）１分子中にけい素原子に結合した水素原子を少なくとも３個有し、２５℃における粘度が５〜１，０００ｍＰａ・ｓの範囲内であるオルガノハイドロジェンポリシロキサン：２〜５０質量部、
（Ｄ）触媒量の白金族金属系触媒
を含有することを特徴とする２５℃における粘度が１００〜１，５００ｍＰａ・ｓの範囲内であるプラスチックフィルム用無溶剤型硬化性シリコーン剥離剤組成物。
〔請求項２〕
更に、（Ｆ）下記一般式（３）で示される２５℃における粘度が１０，０００〜５，０００，０００ｍＰａ・ｓの範囲内であるジオルガノポリシロキサンを（Ａ）成分１００質量部に対して０．５〜５０質量部含む請求項１記載のシリコーン剥離剤組成物。
（Ｒ⁴Ｒ₂ＳｉＯ_1/2）₂（Ｒ₂ＳｉＯ）_Y … （３）
（式中、Ｒは脂肪族不飽和結合を含有しない同一又は異種の一価炭化水素基、Ｒ⁴はＲ，水酸基及びアルケニル基から選択される基であり、Ｙは５００≦Ｙ≦３，０００となる数である。）
〔請求項３〕
請求項１又は２に記載のシリコーン剥離剤組成物の硬化皮膜が少なくとも片面に形成されてなる剥離性プラスチックフィルム。 Accordingly, the present invention provides a solventless curable silicone release agent composition for a plastic film and a peelable plastic film.
[Claim 1]
(A) 1.9 to less than 3.8 alkenyl groups bonded to silicon atoms in one molecule represented by the following general composition formula (1), and a viscosity at 25 ° C. of 50 to 5,000 mPa Branched diorganopolysiloxane in the range of s: 100 parts by mass
(R ₃ SiO _1/2 ) ₃ (R ¹ RSiO) _a (R ₂ SiO) _X (RSiO _3/2 ) ₁ (1)
(In the formula, R ¹ is an alkenyl group having 3 or more carbon atoms, R is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated bond, and a is 1.9 ≦ a <3.8. Satisfied number, X is a number satisfying 40 ≦ X ≦ 450.)
(B) Organopolysiloxane represented by the following general composition formula (2), having an alkenyl group bonded to a silicon atom and having a viscosity at 25 ° C. of 5 to 100 mPa · s: 1 to 50 parts by mass ,

Wherein R ² is an alkenyl group, R is the same or different monovalent hydrocarbon group containing no aliphatic unsaturated bond, R ³ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and m and n are positive The number, p is 0 or a positive number, 0.6 ≦ (n + p) /m≦1.5, 0 ≦ p / (n + p) ≦ 0.05, and m, n, and p are the organopolysiloxanes The viscosity at 25 ° C. is 5 to 100 mPa · s.)
(C) Organohydrogenpolysiloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule and having a viscosity at 25 ° C. in the range of 5 to 1,000 mPa · s: 2 to 50 parts by mass ,
(D) A solvent-free curable silicone release agent composition for plastic films having a viscosity at 25 ° C. in the range of 100 to 1,500 mPa · s, comprising a catalytic amount of a platinum group metal catalyst.
[Claim 2]
Further, (F) a diorganopolysiloxane having a viscosity at 25 ° C. represented by the following general formula (3) in the range of 10,000 to 5,000,000 mPa · s is based on 100 parts by mass of the component (A). The silicone release agent composition according to claim 1, comprising 0.5 to 50 parts by mass.
(R ⁴ R ₂ SiO _1/2 ) ₂ (R ₂ SiO) _Y (3)
Wherein R is the same or different monovalent hydrocarbon group containing no aliphatic unsaturated bond, R ⁴ is a group selected from R, hydroxyl group and alkenyl group, and Y is 500 ≦ Y ≦ 3,000. Is a number.)
[Claim 3]
A peelable plastic film comprising a cured film of the silicone release agent composition according to claim 1 or 2 formed on at least one side.

  Since the solvent-free curable silicone release agent composition of the present invention gives a cured product having good adhesion to a plastic film substrate and good peeling performance, the cured film of this composition is on the plastic film substrate. The peelable plastic film formed on is suitable as a release agent for film adhesive labels, a back treatment agent for film adhesive tapes, and the like.

Hereinafter, the present invention will be described in more detail.
The component (A), which is the main component in the present invention, has a branched shape having an alkenyl group bonded to a silicon atom in the side chain of the molecular chain and having a viscosity at 25 ° C. in the range of 50 to 5,000 mPa · s. It is a diorganopolysiloxane, and the number of alkenyl groups bonded to silicon atoms per molecule is in the range of 1.9 or more and less than 3.8. By reducing the number of crosslinking points, the followability to the deformation of the cured film is improved, so that the adhesion to the plastic film is improved. Such a diorganopolysiloxane is represented by the following formula (1).

(R ₃ SiO _1/2 ) ₃ (R ¹ RSiO) _a (R ₂ SiO) _X (RSiO _3/2 ) ₁ (1)
(In the formula, R ¹ is an alkenyl group having 3 or more carbon atoms, R is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated bond, and a is 1.9 ≦ a <3.8. Satisfied number, X is a number satisfying 40 ≦ X ≦ 450.)

Examples of R ¹ which is an alkenyl group having 3 or more carbon atoms include allyl group, propenyl group, hexenyl group, octenyl group, decenyl group and the like, and hexenyl group and octenyl group are particularly preferable from the viewpoint of curability. It is.

  The same or different monovalent hydrocarbon group containing no aliphatic unsaturated bond represented by R is preferably an alkyl group having 1 to 8 carbon atoms, such as an alkyl group such as a methyl group, an ethyl group or a propyl group, or a phenyl group. , Aryl groups such as tolyl group, and the like, but from the viewpoint of improving curability and peelability, 80 mol% or more is preferably a methyl group.

  Further, a is in the range of 1.9 ≦ a <3.8, more preferably in the range of 2.1 ≦ a <3.7, from the viewpoint of curability and adhesion. When a is less than 1.9, the curability is lowered, and when it is 3.8 or more, the adhesion with the plastic film substrate is lowered.

  Furthermore, from the viewpoint of coating properties, X is 40 ≦ X ≦ 450, preferably 45 ≦ X ≦ 400, so that the viscosity at 25 ° C., which is an appropriate viscosity range as the composition, is 100 to 1,500 mPa · s. do it.

(A) The viscosity in 25 degreeC of a component exists in the range of 50-5,000 mPa * s, Preferably it exists in the range of 70-3,000 mPa * s. When the viscosity is too low, the viscosity as the composition is lowered, and when it is too high, the viscosity as the composition is increased, and both are out of the proper coating viscosity range. In the present invention, the viscosity is a value measured with a rotational viscometer (hereinafter the same).
(A) A component may be individual or may use 2 or more types together.

  The component (B) is an organopolysiloxane having an alkenyl group bonded to a silicon atom represented by the following general composition formula (2). By partially introducing the (B) component having the following rigid structure into the cured film of the main component (A), the synergistic effect significantly improves the adhesion to the plastic substrate. A cured film can be obtained.

（式中、Ｒ²はアルケニル基、Ｒは脂肪族不飽和結合を含有しない同一又は異種の一価炭化水素基、Ｒ³は水素原子又は炭素数１〜８のアルキル基、ｍ，ｎは正数、ｐは０又は正数で、０．６≦（ｎ＋ｐ）／ｍ≦１．５、０≦ｐ／（ｎ＋ｐ）≦０．０５であり、かつ、ｍ，ｎ，ｐはこのオルガノポリシロキサンの２５℃における粘度を５〜１００ｍＰａ・ｓとする数である。）

Wherein R ² is an alkenyl group, R is the same or different monovalent hydrocarbon group containing no aliphatic unsaturated bond, R ³ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and m and n are positive The number, p is 0 or a positive number, 0.6 ≦ (n + p) /m≦1.5, 0 ≦ p / (n + p) ≦ 0.05, and m, n, and p are the organopolysiloxanes The viscosity at 25 ° C. is 5 to 100 mPa · s.)

Examples of the alkenyl group R ² include those having 2 to 10 carbon atoms such as vinyl group, allyl group, propenyl group, hexenyl group, octenyl group, and decenyl group. Is preferred. The same or different monovalent hydrocarbon group R containing no aliphatic unsaturated bond is preferably one having 1 to 8 carbon atoms, such as alkyl group such as methyl group, ethyl group, propyl group, phenyl group, tolyl group. Aryl groups and the like. Examples of the alkyl group for R ³ include a methyl group, an ethyl group, and a propyl group.

  m, n, and p are numbers selected so that the viscosity of the organopolysiloxane at 25 ° C. is 5 to 100 mPa · s, preferably 10 to 70 mPa · s, m and n are positive numbers, p Is 0 or a positive number that satisfies the value of (n + p) / m in the range of 0.6 to 1.5, preferably 0.8 to 1.3. When the value of (n + p) / m is less than 0.6, the adhesion to the plastic substrate is lowered, and when it exceeds 1.5, synthesis is difficult and stability is also lowered. Moreover, p / (n + p) is 0-0.05, Preferably it is the range of 0-0.03. When this value exceeds 0.05, that is, when the number of hydroxyl groups or alkoxy groups bonded to silicon atoms increases, the curability and adhesion deteriorate.

  Furthermore, the viscosity of this organopolysiloxane at 25 ° C. is in the range of 5 to 100 mPa · s, preferably 10 to 70 mPa · s as described above. If it is less than 5 mPa · s, the curability is lowered, and if it exceeds 100 mPa · s, the adhesion is lowered.

  The compounding amount of this organopolysiloxane is 1 to 50 parts by mass, preferably 2 to 45 parts by mass with respect to 100 parts by mass of component (A). When the amount is less than 1 part by mass, good adhesion cannot be obtained, and when the amount exceeds 50 parts by mass, the peeling resistance with the pressure-sensitive adhesive layer increases, that is, heavy peeling occurs.

  The organohydrogenpolysiloxane of component (C) has 3 or more, preferably 4 to 200, hydrogen atoms bonded to silicon atoms in one molecule. This SiH group, component (A) and component (B) ) An alkenyl group in the component undergoes an addition reaction to form a cured film, which may be linear, branched or cyclic, and has a viscosity at 25 ° C. of 5 to 1,000 mPa · s. Should be.

Examples of such organohydrogenpolysiloxanes include, but are not limited to, those represented by the following formula (4).
(R ⁵ R ₂ SiO _1/2 ) _{2 + t} (HRSiO) _r (R ₂ SiO) _s (RSiO _3/2 ) _t (4)

Here, H is a hydrogen atom, R is the same or different, preferably a monovalent hydrocarbon group having 1 to 8 carbon atoms and does not contain an aliphatic unsaturated bond, R ⁵ is a hydrogen atom or R, and t is 0 Or it is 1. When R ⁵ is a hydrogen atom, r and s are numbers satisfying 1 ≦ r ≦ 250, 0 ≦ s ≦ 250, and 8 ≦ r + s ≦ 250. When R ⁵ is R, r and s are 3 ≦ r ≦ 250, 0 ≦ s ≦ 250, and 8 ≦ r + s ≦ 250.

  Examples of R include an alkyl group such as a methyl group, an ethyl group, and a propyl group, and an aryl group such as a phenyl group and a tolyl group. A methyl group is preferable from the viewpoint of improving the addition reaction rate.

(C) The viscosity in 25 degreeC of a component exists in the range of 5-1,000 mPa * s, Preferably it exists in the range of 7-800 mPa * s. If the viscosity is too low, many components volatilize during heat curing, and if it is too high, synthesis becomes difficult, and storage stability also decreases.
(C) A component may be individual or may use 2 or more types together.

  The amount of component (C) is 2 to 50 parts by mass per 100 parts by mass of component (A), but SiH in component (C) relative to the amount of alkenyl groups in component (A) and component (B). It is preferable to adjust by the amount of groups, and it is preferable that SiH group / alkenyl group = 1.0 to 5.0 in terms of molar ratio. When the molar ratio is less than 1.0, a good cured film may not be formed. When the molar ratio is greater than 5.0, the peel resistance may be increased. A more preferred molar ratio is in the range of 1.3 to 4.0.

  The platinum group metal catalyst of component (D) is an addition reaction between an alkenyl group bonded to a silicon atom in components (A) and (B) and a hydrogen atom bonded to a silicon atom in component (C). A known catalyst can be used as an addition reaction catalyst. Examples of such platinum group metal catalysts include platinum-based, palladium-based, and rhodium-based catalysts, and among these, platinum-based catalysts are particularly preferable. Examples of such platinum-based catalysts include chloroplatinic acid, chloroplatinic acid alcohol solutions and aldehyde solutions, chloroplatinic acid complexes with various olefins or vinyl siloxanes, and the like.

  The amount of the platinum group metal catalyst added is a catalytic amount. From the economical viewpoint, a platinum group metal is obtained with respect to the total amount of the components (A), (B), and (C) from the viewpoint of obtaining an excellent cured film. The mass is preferably in the range of 1 to 1,000 ppm.

  In the present invention, an addition reaction inhibitor is preferably added as the component (E), and the addition reaction inhibitor suppresses the catalytic activity of the platinum group metal catalyst that is the component (D) at room temperature. These are so-called pot life extenders that increase the pot life of the composition. For example, various known organic nitrogen compounds, organic phosphorus compounds, acetylene compounds, oxime compounds, organic chloro compounds, etc. More than one type can be used in combination. Particularly preferred are acetylene alcohols and silylated products of acetylene alcohol.

  In addition, although the compounding quantity of (E) component is arbitrary, when the balance of sclerosis | hardenability and pot life is considered, Preferably it is 0.01-10 mass parts with respect to 100 mass parts of (A) component, More preferably, it is 0. The range may be 0.05 to 8 parts by mass. If the blending amount is too small, the pot life may be reduced, and the coating solution may gel in a short time, and if too large, the curability may be decreased.

  In addition to the above components, the composition of the present invention may further contain a diorganopolysiloxane represented by the following formula (3) as a component (F) in order to impart slipperiness. The component (F) is used for the purpose of imparting slipperiness, and at the same time acts to improve adhesion.

(R ⁴ R ₂ SiO _1/2 ) ₂ (R ₂ SiO) _Y (3)
Wherein R is the same or different monovalent hydrocarbon group containing no aliphatic unsaturated bond, R ⁴ is a group selected from R, hydroxyl group and alkenyl group, and Y is 500 ≦ Y ≦ 3,000. Is a number.)

  Here, Y is a number satisfying 500 ≦ Y ≦ 3,000, and preferably 600 ≦ Y ≦ 2,000. If Y is less than 500, the slipping property is not sufficient, and if it exceeds 3,000, the viscosity of the composition increases, which is not preferable in terms of coating properties.

R can be exemplified by the same examples as those exemplified above for the same or different monovalent hydrocarbon groups not containing an aliphatic unsaturated bond, and is a methyl group from the viewpoint of transparency as a composition. It is preferable.
R ⁴ is R, preferably a group selected from an alkenyl group having 2 to 8 carbon atoms or a hydroxyl group, but in order to suppress silicone migration, it is preferably an alkenyl group, particularly a vinyl group. is there.

  The viscosity of component (F) at 25 ° C. is in the range of 10,000 to 5,000,000 mPa · s, and preferably in the range of 20,000 to 2,000,000 mPa · s. If the viscosity is too low, the application of slipperiness may be insufficient, and if it is too high, the viscosity of the composition will increase, which may affect the coatability.

The amount of component (F) is preferably in the range of 0.5 to 50 parts by mass, more preferably in the range of 1.0 to 40 parts by mass with respect to 100 parts by mass of component (A). is there. If the amount is less than 0.5 parts by mass, the application of slipperiness may be insufficient. If the amount exceeds 50 parts by mass, the viscosity of the composition may increase and the coatability may decrease.
In addition, when R ⁴ in the above formula (3) is an alkenyl group, the addition of the alkenyl group in these components and the SiH group in the component (C) together with the components (A) and (B) The amount of SiH groups (SiH groups / alkenyl groups) in component (C) with respect to the amount of alkenyl groups in components (A), (B) and (F) is 1 in molar ratio. It is preferable to use it in the range of .0 to 5.0, particularly 1.3 to 4.0.

  Further, as other additives, antistatic agents exemplified by polyethers and quaternary ammonium salts, vinyltrimethoxysilane, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyl A known silane coupling agent such as trimethoxysilane or a partially hydrolyzed condensate thereof can be used as an adhesion improver. The addition amount may be in a range that does not hinder the effects of the present invention.

  In preparing the silicone release agent composition of the present invention, it is preferable to add the component (D) at the end after uniformly mixing the components other than the component (D). You may use the above together. However, the viscosity at 25 ° C. of the entire composition is in the range of 100 to 1,500 mPa · s, preferably in the range of 120 to 1,200 mPa · s. If the viscosity is less than 100 mPa · s, repelling will occur on the coated surface, and it will be difficult to control thin film coating. It becomes difficult.

  Next, an example of a method for producing a peelable plastic film in which the cured film of the silicone release agent composition of the present invention is formed on at least one side will be described. The peelable plastic film of the present invention can be obtained only by the following method. Other than the manufacturing method, other conventional manufacturing methods can be used.

  Examples of the substrate on which the composition of the present invention is applied to form a cured film include films and sheets obtained from synthetic resins such as polyester, polypropylene, polyethylene, polyvinyl chloride, polytetrafluoroethylene, and polyimide.

In order to apply the composition of the present invention to the substrate, a known method such as a gravure / offset three-roll method or a multi-stage roll method such as five or six can be used. The coating amount is preferably 0.01 to 5.0 g / m ² , and particularly preferably within the range of 0.1 to 2.0 g / m ^2. To do. After apply | coating to a base material, the peelable plastic film of this invention is obtained by making it harden | cure by heating for 1 second-5 minutes at 60-200 degreeC.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples. In addition, all the parts in each example are mass parts, and a viscosity is the value in 25 degreeC measured with the rotational viscometer.
Moreover, the sclerosis | hardenability of a silicone composition, adhesiveness (initial stage and aging), and peeling force were measured with the following method.

(Curable)
A predetermined amount of the silicone composition is applied to the surface of a thin film film or sheet substrate, heated for a predetermined time in a hot air dryer at a predetermined temperature, and the cured silicone film immediately after forming the cured film is reciprocated 10 times with fingers. Curability is evaluated based on the presence or absence of rubbing and clouding of the cured film.
No cloudiness: ○
There is cloudiness: X

(Initial and temporal adhesion)
In the same manner as in the curability test, a predetermined amount of the silicone composition was applied to the surface of the thin film film or sheet substrate, heated in a hot air dryer at a predetermined temperature for a predetermined time, and a cured film was formed. Store in an atmosphere of 25 ° C. and 60% humidity for the following period.
Initial: 1 hour Time: 60 days After storing under each condition, the silicone cured film is rubbed 10 times with a finger, and the adhesion is evaluated by the presence or absence of dropping.
No dropout: ○
Omission: ×
In addition, in the adhesiveness over time, for those dropped out without waiting for 60 days, the number of days at that time is evaluated as the adhesiveness over time.

(Peeling force)
A predetermined amount of silicone composition is applied to the surface of a thin film film or sheet substrate, heated in a hot-air dryer at a predetermined temperature for a predetermined time, and after forming a cured film, it is aged with a separator at 25 ° C. for 24 hours. Then, an acrylic solvent-type pressure-sensitive adhesive / Olivein BPS-5127 (trade name, manufactured by Toyo Ink Manufacturing Co., Ltd.) is applied on the surface of the cured film to a thickness of 110 [mu] m and heat-treated at 100 [deg.] C. for 3 minutes. Next, the same substrate used for silicone coating was bonded to the treated surface as a surface substrate, and after aging at 25 ° C. for 20 hours, the sample was cut to a width of 50 mm, and a tensile tester (manufactured by Shimadzu Corporation) DSC-500 type tester) is used to measure the force (N) required for pulling and peeling the surface substrate at an angle of 180 degrees and a peeling speed of 0.3 m / min.

（Ｂ）成分として、下記構造式Ｂ−１で示され、ビニル価が０．５２ｍｏｌ／ｇであり、粘度が３０ｍＰａ・ｓであるポリシロキサンを９．５部、

（Ｃ）成分として、下記構造式Ｃ−１で示され、粘度が２５ｍＰａ・ｓであるメチルハイドロジェンポリシロキサンを８．２部［ＳｉＨ／｛（Ｓｉ（ＣＨ₂）₄ＣＨ＝ＣＨ₂）＋（ＳｉＣＨ＝ＣＨ₂）｝＝１．８］、

（Ｅ）成分として、１−エチニル−１−シクロヘキサノールを０．３部加え、均一になるまで攪拌した後、（Ｄ）成分として、式：Ｐｔ／［Ｈ₂Ｃ＝Ｃ（ＣＨ₃）₂Ｓｉ］₂Ｏで示される白金とビニルシロキサンとの錯体を組成物全体に対して白金質量換算で９８ｐｐｍになるように添加し、粘度２２０ｍＰａ・ｓのシリコーン組成物を調製した。 [Example 1]
As the component (A), the viscosity is 342 mPa, represented by the following structural formula A-1, having an average of 2.7 methylhexenylsiloxy groups in one molecule, and molecular chain ends blocked with trimethylsiloxy groups. 100 parts of branched dimethylpolysiloxane which is s,

As component (B), 9.5 parts of a polysiloxane represented by the following structural formula B-1 and having a vinyl value of 0.52 mol / g and a viscosity of 30 mPa · s,

As the component (C), 8.2 parts of methylhydrogenpolysiloxane represented by the following structural formula C-1 and having a viscosity of 25 mPa · s [SiH / {(Si (CH ₂ ) ₄ CH═CH ₂ ) + (SiCH = CH ₂ )} = 1.8],

As component (E), 0.3 part of 1-ethynyl-1-cyclohexanol is added and stirred until uniform, and then as component (D), the formula: Pt / [H ₂ C═C (CH ₃ ) ₂ A complex of platinum and vinyl siloxane represented by [Si] ₂ O was added to 98 ppm in terms of platinum mass with respect to the entire composition to prepare a silicone composition having a viscosity of 220 mPa · s.

Next, 0.4 to 0.5 g / m ^{2 of} the obtained silicone composition was applied to a 38 μm thick polyester film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.), and the curability was heated at 120 ° C. for 20 seconds. What formed the cured film was used, and about adhesiveness (initial stage and aging) and peeling force, it measured by using what formed the cured film by heating at 120 degreeC for 30 second, respectively. These measurement results are shown in Table 2.

[Examples 2 and 3, Comparative Examples 1 to 5]
The silicone compositions of Examples 2 and 3 and Comparative Examples 1 to 5 were prepared by combining the components of Example 1 and the components shown in Table 1 below. Various measurements were performed in the same manner as in Example 1 using the obtained silicone composition. Table 2 shows the composition of the composition and the measurement results of the physical properties.

  The solventless silicone composition of the present invention can form a cured film having excellent peeling performance in addition to good adhesion to a plastic film over time.

Claims (3)

(A) 1.9 to less than 3.8 alkenyl groups bonded to silicon atoms in one molecule represented by the following general composition formula (1), and a viscosity at 25 ° C. of 50 to 5,000 mPa Branched diorganopolysiloxane in the range of s: 100 parts by mass
(R ₃ SiO _1/2 ) ₃ (R ¹ RSiO) _a (R ₂ SiO) _X (RSiO _3/2 ) ₁ (1)
(In the formula, R ¹ is an alkenyl group having 3 or more carbon atoms, R is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated bond, and a is 1.9 ≦ a <3.8. Satisfied number, X is a number satisfying 40 ≦ X ≦ 450.)
(B) Organopolysiloxane represented by the following general composition formula (2), having an alkenyl group bonded to a silicon atom and having a viscosity at 25 ° C. of 5 to 100 mPa · s: 1 to 50 parts by mass ,

Wherein R ² is an alkenyl group, R is the same or different monovalent hydrocarbon group containing no aliphatic unsaturated bond, R ³ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and m and n are positive The number, p is 0 or a positive number, 0.6 ≦ (n + p) /m≦1.5, 0 ≦ p / (n + p) ≦ 0.05, and m, n, and p are the organopolysiloxanes The viscosity at 25 ° C. is 5 to 100 mPa · s.)
(C) Organohydrogenpolysiloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule and having a viscosity at 25 ° C. in the range of 5 to 1,000 mPa · s: 2 to 50 parts by mass ,
(D) A solvent-free curable silicone release agent composition for plastic films having a viscosity at 25 ° C. in the range of 100 to 1,500 mPa · s, comprising a catalytic amount of a platinum group metal catalyst. Further, (F) a diorganopolysiloxane having a viscosity at 25 ° C. represented by the following general formula (3) in the range of 10,000 to 5,000,000 mPa · s is based on 100 parts by mass of the component (A). The silicone release agent composition according to claim 1, comprising 0.5 to 50 parts by mass.
(R ⁴ R ₂ SiO _1/2 ) ₂ (R ₂ SiO) _Y (3)
Wherein R is the same or different monovalent hydrocarbon group containing no aliphatic unsaturated bond, R ⁴ is a group selected from R, hydroxyl group and alkenyl group, and Y is 500 ≦ Y ≦ 3,000. Is a number.)   A peelable plastic film comprising a cured film of the silicone release agent composition according to claim 1 or 2 formed on at least one side.