JP2009203281A - Release agent composition and release sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a release sheet which has predetermined peeling force properties and excels in the stability of peeling force with time. <P>SOLUTION: A release agent composition comprising an organopolysiloxane having at least two alkenyl groups in the molecule and an aryl group in the side chain, a linear organopolysiloxane having a mass average molecular weight of 50,000-500,000 having an alkenyl group at each molecular terminal in the molecule or not having an alkenyl group, a silicone resin, and a polyorganohydrogensiloxane having at least two silicon-bonded hydrogen atoms in the molecule is used in a release agent layer of the release sheet. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a release sheet having a predetermined release force characteristic and excellent in the temporal stability of the release force and a release agent composition used therefor.

  A general adhesive label used in a handler label or the like is configured by attaching a plurality of labels to a release sheet. In such general-purpose pressure-sensitive adhesive labels, if the peel force is too low, the label may drop off from the release sheet before use. If the peel force is too high, the label is peeled off from the release sheet when the label is applied. It may be necessary to have a predetermined peeling force characteristic because a failure that cannot be performed may occur.

  Moreover, when an adhesive label is manufactured, the factory where a release sheet is manufactured may differ from the factory where an adhesive label is manufactured from the release sheet. In such a case, several days to several tens of days elapse from the production of the release sheet to the production of the pressure-sensitive adhesive label, and therefore the elapsed period, that is, the seasoning period, may be different for each release sheet. However, the conventional release sheet does not have sufficient stability over time, and the peel force may fluctuate during the seasoning period, resulting in variations in the peel force characteristics of the pressure-sensitive adhesive label. Therefore, in the conventional release sheet, the release force characteristic of the pressure-sensitive adhesive label is not necessarily made suitable.

For example, Patent Documents 1 and 2 disclose a release agent composition containing a linear organopolysiloxane having a phenyl group in the side chain and a linear organopolysiloxane having no phenyl group in the side chain. Has been. In the release sheet using these release agent compositions, the peeling force is kept low both in the case of high speed peeling and in the case of low speed peeling, and the speed dependency of the peeling force is improved.
JP-A-7-82487 JP-A-2-187466

  However, since the release agent compositions described in these patent documents have a low release force of the release sheet, when used for general pressure-sensitive adhesive labels, problems such as the label falling off the release sheet may occur before use. . Moreover, the said patent document does not disclose at all about a specific blend for improving the temporal stability of the peeling force.

  Therefore, the present invention has been made in view of the above problems, and has a peeling force characteristic suitable for general-purpose pressure-sensitive adhesive labels, and has excellent aging stability, and is used for the peeling sheet. It is an object of the present invention to provide a release agent composition.

The release agent composition according to the present invention includes the following components (A) to (D).
(A) 100 parts by mass of an organopolysiloxane having at least two alkenyl groups in one molecule and an aryl group in the side chain (B) having an alkenyl group only at each molecular end in one molecule, or alkenyl 1-30 parts by weight of a linear organopolysiloxane having no weight average molecular weight of 50,000-500,000 (C) 1-50 parts by weight of silicone resin (D) At least two silicon atoms in one molecule 1 to 30 parts by mass of organohydrogenpolysiloxane having bonded hydrogen atoms

The component (A) is, for example, an organopolysiloxane represented by the general formula (I).
R ¹ _X R _(3-X) SiO (R ₂ SiO) _a (RR ¹ SiO) _b (RR ² SiO) _c OSiR ¹ _y R _(3-y)・ ・ ・ ・ (I)
Here, in the formula (I), R is the same or different monovalent hydrocarbon having no aliphatic unsaturated bond, R ¹ is an alkenyl group, and R ² is an aryl group. A, b, c, x, and y represent natural numbers, and 1 ≦ x ≦ 3 and 1 ≦ y ≦ 3. Further, 0.73 ≦ a / (a + b + c) ≦ 0.99, 0.005 ≦ b / (a + b + c) ≦ 0.2, 0.005 ≦ c / (a + b + c) ≦ 0. 07.

Component (B) is, for example, an organopolysiloxane represented by the general formula (II).
R ¹ _v R _(3-v) SiO (R ₂ SiO) _d SiR ¹ _w R _(3-w) ... (II)
In the formula (II), R is the same or different monovalent hydrocarbon having no aliphatic unsaturated bond, and R ¹ is an alkenyl group. D, v, and w represent natural numbers, and 0 ≦ v ≦ 3 and 0 ≦ w ≦ 3.

The component (C) includes SiO ₂ units, (CH ₃ ) ₃ SiO _1/2 units, and CH ₂ ═CH (CH ₂ ) _Z (CH ₃ ) ₂ SiO _1/2 units (wherein z is 0 to 4). And / or a resin having a structure having a HO (CH ₃ ) ₂ SiO _1/2 unit.

  The release sheet according to the present invention has a release agent layer formed by curing the release agent composition described above.

  It is possible to provide a release sheet that does not easily change peel strength with time and has peel strength characteristics suitable for general-purpose pressure-sensitive adhesive labels.

Hereinafter, the present invention will be described in more detail using embodiments.
The release sheet according to the present invention is used as a member of an adhesive body. This pressure-sensitive adhesive is a laminate in which a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface of a pressure-sensitive adhesive sheet base material is laminated on the release agent layer of the release sheet so that the release agent layer and the pressure-sensitive adhesive layer are in contact with each other. It is.

  The pressure-sensitive adhesive body is applied to a pressure-sensitive adhesive label sheet in which, for example, a plurality of pressure-sensitive adhesive sheets (pressure-sensitive adhesive labels) cut into a predetermined size are continuously provided on a long release sheet. This pressure-sensitive adhesive label sheet is punched so that the pressure-sensitive adhesive sheet has a predetermined size by a flat die or a die-cut roll so as to surround a predetermined portion from the surface of the long pressure-sensitive adhesive body on the pressure-sensitive adhesive sheet substrate side. Is applied, unnecessary parts of the pressure-sensitive adhesive sheet (peripheral parts of the pressure-sensitive adhesive label) are removed.

  The release agent layer is formed by applying a release agent composition diluted with an appropriate organic solvent on a release sheet base material, and then heating or using a combination of heating and light irradiation such as ultraviolet rays. Is formed as a cured coating. The release agent composition used for the release agent layer contains the following components (A) to (E).

As the component (A), an organopolysiloxane having at least two alkenyl groups in one molecule and an aryl group in the side chain, preferably an organopolysiloxane represented by the following general formula (I) is used. .
R ¹ _X R _(3-X) SiO (R ₂ SiO) _a (RR ¹ SiO) _b (RR ² SiO) _c OSiR ¹ _y R _(3-y)・ ・ ・ ・ (I)

In the formula (I), R is the same or different monovalent hydrocarbon having no aliphatic unsaturated bond, R ¹ is an alkenyl group, and R ² is an aryl group. A, b, c, x, and y represent natural numbers, and 1 ≦ x ≦ 3 and 1 ≦ y ≦ 3. Further, 0.73 ≦ a / (a + b + c) ≦ 0.99, 0.005 ≦ b / (a + b + c) ≦ 0.2, 0.005 ≦ c / (a + b + c) ≦ 0. 07, more preferably 0.8 ≦ a / (a + b + c) ≦ 0.96, 0.02 ≦ b / (a + b + c) ≦ 0.15, 0.02 ≦ c / (a + b + c) ≦ 0.05, and a> b and a> c. The mass average molecular weight of the component (A) is preferably 3,000 to 350,000, and more preferably 5,000 to 250,000.

In the general formula (I), R has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and examples thereof include alkyl groups such as a methyl group, an ethyl group, and a propyl group. Moreover, it is preferable that 80 mol% or more of R is a methyl group from a viewpoint of sclerosis | hardenability and peelability. Examples of the alkenyl group for R ¹ include those having 2 to 10 carbon atoms such as a vinyl group, an allyl group, a propenyl group, and a hexenyl group. Examples of the aryl group for R ² include a phenyl group and a tolyl group.

As the component (B), a linear organopolysiloxane having a mass average molecular weight of 50,000 to 500,000 having an alkenyl group only at each molecular terminal or no alkenyl group is used. Since component (B) does not have an aliphatic unsaturated bond such as an alkenyl group in the side chain, only the molecular end is subjected to an addition reaction by the crosslinking agent described later, or both the molecular end and the side chain are added. no response. Specifically, the component (B) is preferably an organopolysiloxane represented by the following general formula (II).
R ¹ _v R _(3-v) SiO (R ₂ SiO) _d SiR ¹ _w R _(3-w) ... (II)

In the formula (II), R is the same or different monovalent hydrocarbon having no aliphatic unsaturated bond, and R ¹ is an alkenyl group. d, v, and w represent natural numbers, and 0 ≦ v ≦ 3 and 0 ≦ w ≦ 3. Preferably, 1 ≦ v ≦ 3 and 1 ≦ w ≦ 3, and it is better to have an alkenyl group at the molecular end. (B) It is preferable that the mass mean molecular weights of a component are 100,000-500,000, More preferably, it is 200,000-500,000. And preferably, the mass average molecular weight of the component (B) should be larger than the mass average molecular weight of the component (A). In the release agent composition, the component (B) is contained in an amount of 1 to 30 parts by mass with respect to 100 parts by mass of the component (A). When the component (B) is less than 1 part by mass, the aging stability of the peeling force is not sufficiently improved, and when it is added in an amount of more than 30 parts by mass, the peeling force is lower than a desired value.

In the general formula (II), R has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and examples thereof include alkyl groups such as a methyl group, an ethyl group, and a propyl group. A methyl group is preferred. Examples of the alkenyl group for R ¹ include those having 2 to 10 carbon atoms such as a vinyl group, an allyl group, a propenyl group, and a hexenyl group.

As the component (C), a silicone resin is used. For example, SiO ₂ unit, (CH ₃ ) ₃ SiO _1/2 unit, and CH ₂ = CH (CH ₂ ) _z (CH ₃ ) ₂ SiO _1/2 unit (Wherein z represents an integer of 0 to 4), a resin having a structure, a SiO ₂ unit, a (CH ₃ ) ₃ SiO _1/2 unit, and a HO (CH ₃ ) ₂ SiO _1/2 unit Or SiO ₂ units, (CH ₃ ) ₃ SiO _1/2 units, CH ₂ = CH (CH ₂ ) _z (CH ₃ ) ₂ SiO _1/2 units, and HO (CH ₃ ) ₂ SiO _1/2 Resins having a structure with units are used. For example, when the release sheet requires a relatively high peel force, the resin preferably has HO (CH ₃ ) ₂ SiO _1/2 units, and when a relatively low peel force is required, CH ₂ = CH ( It preferably has CH ₂ ) _Z (CH ₃ ) ₂ SiO _1/2 units. In the release agent composition, the component (C) is contained in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the component (A). When the component (C) is less than 1 mass, the peel strength of the release sheet is not sufficiently increased, and there is a possibility that label dropping or the like occurs in the pressure-sensitive adhesive label. Moreover, when it mix | blends more than 50 mass parts, there exists a possibility that the peeling force of a peeling sheet may become high too much.

  As the component (D), an organohydrogenpolysiloxane crosslinking agent having at least two silicon-bonded hydrogen atoms (SiH) in one molecule is used. Specifically, dimethylhydrogensiloxy group end-capped dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group end-capped dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group end-capped methylhydrogenpolysiloxane, Poly (hydrogensilsesquioxane) etc. are mentioned. In the present embodiment, a cured film is formed by an addition reaction between the crosslinking agent SiH and the alkenyl group in the release agent composition.

  In the release agent composition, the component (D) is contained in an amount of 1 to 30 parts by mass with respect to 100 parts by mass of the component (A). The component (D) is added so that the number of silicon-bonded hydrogen atoms (SiH) is preferably 1.0 to 5.0 (molar ratio) with respect to the number of alkenyl groups in the release agent composition. More preferably, it is 1.1-4.0 (molar ratio), More preferably, it is 1.2-3.0 (molar ratio). When the molar ratio is lower than the lower limit, the curability of the composition is deteriorated. When the molar ratio is higher than the upper limit, the peeling force of the release agent becomes too heavy, and the aging stability of the peeling force may be lowered.

  The component (E) is a platinum group metal catalyst, and a catalytic amount is added to the release agent composition. Examples of platinum compounds used in platinum group metal catalysts include particulate platinum, particulate platinum adsorbed on a carbon powder support, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, palladium And rhodium catalyst. The platinum group metal catalyst is added in an amount of about 1 to 1000 ppm as a platinum metal with respect to the total amount of the addition reaction type organopolysiloxane and the crosslinking agent.

  In addition to the above components (A) to (E), a reaction inhibitor, an adhesion improver, and the like may be added to the release agent composition as desired. Moreover, when light irradiation, such as ultraviolet irradiation, is performed in addition to heating in the curing step after application of the release agent, a photoinitiator may be added.

  The release sheet base material and the pressure sensitive adhesive sheet base material can be appropriately selected from known base materials known as release sheets or base materials for pressure sensitive adhesive sheets, and are formed of, for example, a thermoplastic resin or the like. A resin film, paper, metal foil, or a composite thereof can be used.

  As the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer, a known pressure-sensitive adhesive can be used without particular limitation, and for example, an acrylic pressure-sensitive adhesive is used. The pressure-sensitive adhesive body is formed, for example, by applying a pressure-sensitive adhesive on a release agent layer to form a pressure-sensitive adhesive layer, and further sticking a pressure-sensitive adhesive sheet substrate on the pressure-sensitive adhesive layer. The pressure-sensitive adhesive body may be formed by bonding the pressure-sensitive adhesive sheet and the release sheet after the pressure-sensitive adhesive layer is formed on the pressure-sensitive adhesive sheet substrate. The release agent composition and the pressure-sensitive adhesive are applied by existing methods such as a gravure coating method, a bar coating method, a spray coating method, a spin coating method, a knife coating method, a roll coating method, and a die coating method.

  According to the configuration of the release agent composition, in this embodiment, the peeling force of the release sheet to the pressure-sensitive adhesive sheet can be set to 200 to 2000 mN / 50 mm, which is a value suitable for a general-purpose pressure-sensitive adhesive label. When the release sheet has a release force of 200 mN or more, label jumping or the like, in which the label is unexpectedly peeled off from the release sheet during labeling, is prevented. Moreover, it is prevented that a label becomes difficult to peel from a peeling sheet by making peeling force into 2000 mN or less. In order to further improve the peeling performance of the label, the peeling force is preferably 220 to 1800 mN / 50 mm, and more preferably 250 to 1500 mN / 50 mm.

  Moreover, in this embodiment, the time-dependent change of the peeling force in a peeling sheet is prevented by the structure of the said release agent composition. The mechanism is guessed as follows. In order to ensure curability, the component (D), which is a cross-linking agent, is generally added in an equivalent amount or in excess to the alkenyl group in the release agent composition to leave unreacted SiH in the release agent layer. Is. Normally, unreacted SiH is also present, for example, near the surface of the release agent layer, that is, near the interface with the pressure-sensitive adhesive layer, and increases the initial peel force immediately after the production of the release sheet. However, since this unreacted SiH has low stability and disappears with the passage of time, the peeling force of the release sheet is lowered with the passage of time, and this has caused a change with time of the peeling force in the conventional release sheet.

  In this embodiment, as the organopolysiloxane component, a component (A) having a relatively small molecular weight and having an aryl group and a component (B) having a relatively large molecular weight and having no aryl group are used. These components (A) and (B) are uniformly dispersed in the solvent-diluted release agent composition, but are hardly compatible with each other due to differences in molecular weight, molecular structure, polarity, etc. The component (A) and the component (B) are relatively separated from each other to form a film. The component (B) tends to be easily formed near the surface of the release agent layer in the cured coating, that is, near the interface with the pressure-sensitive adhesive layer because of its molecular weight, molecular structure, release agent composition, and the like. ) Component is less likely to be present near the interface.

  Here, since the component (D) tends to be compatible with the component (A) in the cured film due to its molecular weight and the interaction between SiH and aryl groups, the release agent layer and the component (A) It becomes difficult to exist at the interface of the pressure-sensitive adhesive layer. Therefore, in this embodiment, it is presumed that the initial increase in the peel force immediately after the release sheet production caused by the unreacted (D) component (SiH) is suppressed, and as a result, the change in peel force with time is prevented. Is done.

In addition, in this specification, a mass average molecular weight means what measured each organopolysiloxane by gel permeation chromatography (GPC), and calculated | required as a polystyrene conversion value. The measurement conditions are as follows.
Measuring device: Shodex GPC SYSTEM-21H (trade name, Showa Denko)
Column: Waters, two styragel (R) HR5E are used Measurement solvent: Chloroform Measurement temperature: 40 ° C
Flow rate: 1.0 ml / min Sample concentration: 1.0%

  The present invention will be described below with reference to examples, but the present invention is not limited to the configurations of the following examples.

[Example 1]
Dimethylsiloxane unit is 94 mol%, methylvinylsiloxane unit is 3 mol%, methylphenylsiloxane unit is 3 mol%, and the molecular average molecular weight is 100,000. 100 parts by mass of a methylphenylsiloxane copolymer (component (A)), 3 parts by mass of dimethylpolysiloxane blocked with a dimethylvinylsilyl group blocked at both ends of the molecular chain having a mass average molecular weight of 4.0 × 10 ⁵ (component (B)), , Silicone resin (trade name “BY24-843” manufactured by Toray Dow Corning Co., Ltd., solid content 50 mass%) (component (C)) 5 parts by mass, and trimethylsiloxy group end-capped methylhydrogen having a mass average molecular weight of 3000 Polysiloxane (made by Toray Dow Corning, trade name “SP 7297 ") (component (D)) and 10 parts by weight of toluene diluted with 900 parts by weight of toluene, and then mixed with platinum catalyst (trade name" SRX-212 "manufactured by Toray Dow Corning) (component (E)) Was added in an amount of 1% by mass with respect to the nonvolatile content to obtain a release agent composition. The silicone resin was a resin having a structure composed of SiO ₂ units, (CH ₃ ) ₃ SiO _1/2 units, and HO (CH ₃ ) ₂ SiO _1/2 units. Further, the molar ratio of silicon-bonded hydrogen atoms to alkenyl groups in the release agent composition was 1.2. Next, a release agent composition was uniformly applied to a glassine paper having a basis weight of 80 g / m ² as a release sheet substrate so that the application amount was 1.0 g / m ² , and then heated at 110 ° C. for 30 seconds. The release agent composition was cured by treatment to obtain a release sheet having a release agent layer formed on one surface of the substrate.

[Example 2]
(B) It implemented like Example 1 except having added the addition amount of the component to 10 mass parts.

[Example 3]
(B) It implemented similarly to Example 1 except having added the addition amount of the component to 20 mass parts.

[Example 4]
(C) It implemented similarly to Example 2 except having made the addition amount of the component (silicone resin) into 10 mass parts.

[Comparative Example 1]
(B) It implemented similarly to Example 1 except having added the addition amount of the component to 0.5 mass part.

[Comparative Example 2]
In place of the component (A) in Example 3, the dimethylsiloxane unit was 97 mol%, the methylvinylsiloxane unit was 3 mol%, and the dimethylvinylsilyl group-blocked dimethylsiloxanesilyl group having a mass average molecular weight of 100,000 was obtained. The same operation as in Example 3 was carried out except that a vinylsiloxane copolymer was used.

[Comparative Example 3]
Instead of the component (A) in Example 1, the dimethylsiloxane unit was 97 mol%, the methylvinylsiloxane unit was 3 mol%, and the molecular chain both ends dimethylvinylsilyl group-capped dimethylsiloxane-methyl having a mass average molecular weight of 100,000. The same procedure as in Example 1 was performed except that a vinylsiloxane copolymer was used and the component (B) was not added to the release agent composition.

[Comparative Example 4]
(B) It implemented similarly to Example 1 except having made the mass mean molecular weight of the component into 3.0 * 10 < ⁴ >.

[Comparative Example 5]
(B) It implemented similarly to Example 1 except not having added a component and (C) component to the release agent composition.

The release sheets of each example and comparative example were evaluated by the following methods.
(1) Residual adhesion rate A polyester tape (product name: NO.31B, manufactured by Nitto Denko Corporation) is bonded to the surface of the release agent layer side of a release sheet having a width of 25 mm and a length of 20 cm, and 20 g / cm ² thereon. After aging at 70 ° C. for 24 hours, the polyester tape was peeled from the release sheet and attached to a stainless steel plate. The resistance (A) when the polyester tape was peeled off from the stainless steel plate at an angle of 180 ° at a speed of 0.3 m / min was measured. A polyester tape not bonded to a release sheet as a blank was bonded to a stainless steel plate, and the resistance (B) was measured in the same manner. The residual adhesion rate was set to 100 × (A / B), and the following evaluation criteria were used for evaluation.
○: The residual adhesion rate is 90% or more, and the residual adhesion rate is good.
Δ: Residual adhesion rate is 80% or more and less than 90%, and can be used.
X: Residual adhesion rate is less than 80% and cannot be used.

(2) Peeling force After leaving the release sheet obtained in each Example and Comparative Example for one day under the condition of 23 ° C. and 50% humidity, using an applicator, an acrylic adhesive (manufactured by Toyo Ink Co., Ltd.) The name “BPS5127”) was applied onto the release agent layer of the release sheet so that the coating amount after drying was 30 g / m ² . After the release sheet coated with the pressure-sensitive adhesive is dried in an oven at 100 ° C. for 1 minute, a high-quality paper having a basis weight of 64 g / m ² that is a pressure-sensitive adhesive sheet substrate (trade name “NPI foam” manufactured by Nippon Paper Industries Co., Ltd.) A bonded adhesive was prepared on the adhesive layer. Moreover, the adhesive body was similarly produced using the release sheet obtained by each Example and the comparative example which was left for 30 days on the conditions of 23 degreeC humidity 50%.

  The prepared pressure-sensitive adhesive was further allowed to stand for 1 day, and was then cut into a width of 50 mm and a length of 150 mm, and the peel strength was measured. The peeling force was measured using a tensile tester, and the peeling sheet was fixed, and the peeling sheet was peeled from the pressure-sensitive adhesive sheet by pulling the pressure-sensitive adhesive sheet in the 180 ° direction at a peeling speed of 0.3 m / min. . Note that the pressure sensitive adhesive was allowed to stand and the peel force was measured in an environment of a temperature of 23 ° C. and a humidity of 50%.

The peel force change rate (F2 / F1) is determined by setting F1 as the peel force in the pressure-sensitive adhesive prepared after leaving the release sheet for one day and F2 as the peel force in the pressure-sensitive adhesive prepared after leaving the release sheet for 30 days. Evaluation was performed according to the following evaluation criteria.
○: F1 and F2 are 200 to 2000 mN / 50 mm, and 0.6 ≦ F2 / F1 ≦ 1.4.
Δ: F1 and F2 are 200 to 2000 mN / 50 mm, and 0.5 ≦ F2 / F1 <0.6 or 1.4 <F2 / F1 ≦ 1.5.
X: F1 or F2 is outside the range of 200 to 2000 mN / 50 mm, or is outside the range of 0.5 ≦ F2 / F1 ≦ 1.5.

  As is clear from the above evaluation results, the release sheets of Examples 1 to 4 containing a predetermined amount of the components (A), (B), and (C) of the present invention have a good residual adhesion rate, and It had a peeling force suitable for use in an adhesive label, and was excellent in the temporal stability of the peeling force.

Claims (5)

A release agent composition comprising the following components (A) to (D):
(A) 100 parts by mass of an organopolysiloxane having at least two alkenyl groups in one molecule and an aryl group in the side chain (B) having an alkenyl group only at each molecular end in one molecule, or alkenyl 1-30 parts by weight of a linear organopolysiloxane having no weight average molecular weight of 50,000-500,000 (C) 1-50 parts by weight of silicone resin (D) At least two silicon atoms in one molecule 1 to 30 parts by mass of organohydrogenpolysiloxane having bonded hydrogen atoms The release agent composition according to claim 1, wherein the component (A) is an organopolysiloxane represented by the general formula (I).
R ¹ _X R _(3-X) SiO (R ₂ SiO) _a (RR ¹ SiO) _b (RR ² SiO) _c OSiR ¹ _y R _(3-y)・ ・ ・ ・ (I)
In the formula (I), R is the same or different monovalent hydrocarbon having no aliphatic unsaturated bond, R ¹ is an alkenyl group, and R ² is an aryl group. A, b, c, x, and y represent natural numbers, and 1 ≦ x ≦ 3 and 1 ≦ y ≦ 3. Further, 0.73 ≦ a / (a + b + c) ≦ 0.99, 0.005 ≦ b / (a + b + c) ≦ 0.2, 0.005 ≦ c / (a + b + c) ≦ 0. 07. The release agent composition according to claim 1, wherein the component (B) is an organopolysiloxane represented by the general formula (II).
R ¹ _v R _(3-v) SiO (R ₂ SiO) _d SiR ¹ _w R _(3-w) ... (II)
In the formula (II), R is the same or different monovalent hydrocarbon having no aliphatic unsaturated bond, and R ¹ is an alkenyl group. D, v, and w represent natural numbers, and 0 ≦ v ≦ 3 and 0 ≦ w ≦ 3. The component (C) includes SiO ₂ units, (CH ₃ ) ₃ SiO _1/2 units, and CH ₂ ═CH (CH ₂ ) _Z (CH ₃ ) ₂ SiO _1/2 units (wherein z is 0 to 0). The release agent composition according to claim 1, which is a resin having a structure having a natural number of 4) and / or HO (CH ₃ ) ₂ SiO _1/2 units.   A release sheet comprising a release agent layer formed by curing the release agent composition according to any one of claims 1 to 4.