JP3022101B2 - Release organopolysiloxane composition and release paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a releasable organopolysiloxane composition and a release paper having good adhesion to a substrate and providing a cured film having good releasability to an adhesive substance. About.

[0002]

2. Description of the Related Art
By forming a peelable cured film of a heat- or ultraviolet-curable organopolysiloxane composition on the surface of a substrate such as general paper, processed paper, and plastic film, the peeling between the substrate and the adhesive substance is facilitated, Prevention of blocking between the substrates has been carried out, and as such an organopolysiloxane composition, an addition reaction type is known (JP-B-52-40918, JP-B-52-91818).
No. 53383).

A peelable organopolysiloxane composition for forming the peelable cured film is usually prepared from a viewpoint of productivity at a temperature of 100 to 200 ° C. for a curing time of 30 seconds or less, and for a short time of 10 seconds or less. In order to improve productivity, and the substrate on which the cured film is formed has poor heat resistance, it is possible to cure the releasable organopolysiloxane composition at a lower temperature and in a shorter time. Has been requested.

However, a cured film obtained by curing a conventional addition-removable release organopolysiloxane composition at a low temperature and in a short time is inferior in adhesion to the base material. When the surface is rubbed, there is a problem that the cured film easily falls off the substrate.

[0005] The present invention has been made in view of the above circumstances,
General paper, by improving the adhesion to the substrate consisting of processed paper or plastic film, even when cured at low temperature and in a short time, while having excellent adhesion to the above-mentioned substrate, against adhesive substances It is an object of the present invention to provide an addition reaction type release organopolysiloxane composition for release paper and a release paper which can be cured by heat and / or ultraviolet light to give a cured film having good release properties.

[0006]

The inventors of the present invention have conducted intensive studies to achieve the above object. As a result, (A) a vinyl group having at least two vinyl groups directly bonded to a silicon atom in one molecule. Containing organopolysiloxane, (B) 1
At least two hydrogen atoms directly connected to silicon atoms in the molecule
(C) an acryl group or a methacryl group bonded to a silicon atom via an alkylene group in one molecule; and (D) an organopolysiloxane composition containing a platinum catalyst. And / or when an organopolysiloxane having at least one epoxy group, at least one hydrogen atom directly bonded to a silicon atom, and at least one alkoxysilyl group bonded via an alkylene group, the component (C) is an organopolysiloxane. Since it acts as an adhesion improver in the composition, it has excellent adhesion to a substrate as compared with a conventional releasable organopolysiloxane composition. In particular, the composition has a curing time of 10 seconds or less at a temperature of 70 to 100 ° C. Even when cured at low temperature and in a short time, it can be used as a base material for general paper, processed paper, and plastic films. With an excellent adhesion, and found that can give a cured film having a good peeling property against the adhesive material, the present invention has been accomplished.

Accordingly, the present invention relates to (I) a release paper for release paper, which is applied and cured on a substrate made of general paper, processed paper or plastic film, and in which an adhesive substance is adhered onto the cured film. (A) 100 parts by weight of a vinyl group-containing organopolysiloxane having at least two vinyl groups directly bonded to silicon atoms in one molecule, and (B) silicon in one molecule. An organic group other than a hydrogen atom directly bonded to a silicon atom having at least two hydrogen atoms directly bonded to an atom, an alkyl group, an aryl group, an aralkyl group or a part or all of the hydrogen atoms of these groups being a halogen atom An organohydrogenpolysiloxane which is a group substituted with: 0.1 to 20 parts by weight, and a molar ratio of HSi に 対 す る to a vinyl group of the component (A) is 0.5 to 10; (C) an acrylic or methacrylic group and / or an epoxy group bonded to a silicon atom via an alkylene group, a hydrogen atom directly bonded to the silicon atom, and a Having at least one alkoxysilyl group bonded to each other by:
0.1 to 20 parts by weight, (D) platinum-based catalyst: a peelable organopolysiloxane composition comprising 0.015 to 0.1 part by weight as platinum, (II) general paper, Provided is a release paper in which a cured film of the above-mentioned releasable organopolysiloxane composition is formed on a substrate made of processed paper or a plastic film.

Hereinafter, the present invention will be described in more detail.
(A) The vinyl group-containing organopolysiloxane of the component is 1
At least two vinyl groups bonded to silicon atoms in the molecule
It has one.

In this case, the organic group other than the vinyl group includes an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group and a hexyl group; an aryl group such as a phenyl group;
Aralkyl groups such as -phenylethyl group and β-phenylpropyl group, and chloromethyl groups in which part or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as fluorine atoms and chlorine atoms, 3,3,3- And a substituted hydrocarbon group such as a trifluoropropyl group. Of these, a methyl group is preferable in order to obtain a cured film which is easy to synthesize and exhibits excellent releasability from an adhesive substance.

The organopolysiloxane may be linear or branched, and may be a mixture thereof. However, the molecular chain terminal of the organopolysiloxane has a vinyl group from the viewpoint of curability of the organopolysiloxane composition. It is particularly preferable to have three vinyl groups at the molecular chain terminals from the viewpoint of adhesion between the substrate and the cured film. As such an organopolysiloxane containing three vinyl groups at the terminal, one represented by the following formula (1) is preferable.

[0011]

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Here, R ¹ is a substituted or unsubstituted monovalent hydrocarbon group containing no aliphatic unsaturated bond, and preferably has 1 to 12 carbon atoms, particularly 1 to 3 carbon atoms. Examples of the organic group other than the group include those exemplified above.
Here, m is an integer of 0 to 100, particularly preferably 0 to 20, and n is an integer of 100 to 8000, particularly preferably 200 to 500.

The viscosity of the organopolysiloxane (A) at 25 ° C. is not particularly limited, but the viscosity is preferably set to 60 cs (centistokes) or more from the viewpoint of the curability of the silicone composition. preferable. The silicone composition of the present invention is applied to a substrate and has a thickness of several μm.
When the following cured film is obtained, when the viscosity of the organopolysiloxane is 50,000 cs or more, it is preferable to use the component (A) dissolved in an organic solvent from the viewpoint of coatability.

Next, the organohydrogenpolysiloxane of the component (B) contains at least two hydrogen atoms directly bonded to silicon atoms in the molecule, and other than hydrogen atoms directly bonded to silicon atoms. As the organic group, those similar to those exemplified in the organopolysiloxane of the component (A), that is, an alkyl group, an aryl group, an aralkyl group or a group in which part or all of the hydrogen atoms of these groups are substituted with halogen atoms are mentioned. No.

As the component (B), specifically, α, ω-bis (dimethylhydrogensilyl) polydimethylsiloxane, α, ω-bis (trimethylsilyl) polymethylhydrogenpolysiloxane, α, ω-bis (trimethylsilyl) ) Poly (methylhydrogen) (dimethyl) siloxane copolymer and the like.

The molecular shape of the component (B) may be linear, branched or cyclic, and the viscosity at 25 ° C. is preferably 10 to 50 cs.

The amount of the component (B) is 100 parts (A)
It is preferably 0.1 to 20 parts, more preferably 2 to 15 parts with respect to parts (parts by weight, hereinafter the same). This compounding amount is 0.1
If the amount is less than 20 parts, the curability is deteriorated, and if the amount is more than 20 parts, the peelability from the adhesive substance may be unstable.
The molar ratio of HSi≡ to the vinyl group of the component (A) can be adjusted in the range of 0.5 to 10 according to the purpose.

The component (C) has an acryl group, a methacryl group or an epoxy group bonded to a silicon atom via an alkylene group in one molecule, a hydrogen atom directly bonded to the silicon atom, and a hydrogen atom bonded via an alkylene group. And at least one alkoxysilyl group. Examples thereof include a cyclic siloxane represented by the following formula (2) and a linear siloxane represented by the following formula (3).

[0019]

Embedded image (Provided that R ¹ is a substituted or unsubstituted monovalent hydrocarbon group containing no aliphatic unsaturated bond, R ² is an acryl group-containing alkylene group, a methacryl group-containing alkylene group or an epoxy group-containing alkylene group, and R ³ is an alkoxy group. Represents a silyl group-containing alkylene group, wherein t and x are integers of 0 or more, s, u, v,
w, y, and z are integers of 1 or more. )

[0020] Here, R ¹ is the same as R ¹ in the formula (1), also the acrylic group, a methacrylic group, an epoxy group, an organic group having an alkoxysilyl group-containing organic group,
Examples thereof include an alkylene group in which an oxygen atom and a sulfur atom may be interposed. In this case, a part or all of the hydrogen atoms of the alkylene group may be substituted with a hydroxyl group or the like. In this case, the alkylene group of the alkylene group preferably has 1 to 8 carbon atoms, particularly preferably 2 to 6 carbon atoms. The alkoxy group of the alkoxysilyl group preferably has 1 to 5 carbon atoms. The alkoxysilyl group is preferably a trialkoxysilyl group, but may be an alkyldialkoxysilyl group, a dialkylalkoxysilyl group, or the like (the alkyl group preferably has 1 to 5 carbon atoms).

Examples of the above-mentioned acryl group, methacryl group, epoxy group and alkoxysilyl group-containing alkylene group include the following.

[0022]

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In the above formula (2), t is an integer of 0 or more, s, u, and v are integers of 1 or more, and 3 ≦ s + t +
It is preferable that u + v ≦ 8 is satisfied. In the above formula (3), x is an integer of 0 or more, w, y, and z are integers of 1 or more, and preferably satisfies 3 ≦ w + x + y + z ≦ 40.

The amount of the component (C) is 100 parts.
The amount is preferably 0.1 to 20 parts, particularly 1 to 10 parts with respect to parts. If the amount of the component (C) is less than 0.1 part, the adhesion between the cured film and the substrate is not sufficient. If the amount exceeds 20 parts, the peelability between the cured film and the adhesive substance may be unstable.

The platinum catalyst of the component (D) cures the silicone rubber compound by an addition reaction between the vinyl group of the diorganopolysiloxane of the component (A) and the hydrosilyl group of the organohydrogenpolysiloxane of the component (B). Catalyst. As the platinum-based catalyst, platinum alone,
Platinum compounds and platinum complexes are included, and specific examples thereof include chloroplatinic acid such as chloroplatinic primary acid and chloroplatinic acid, alcohol compounds of chloroplatinic acid, aldehyde compounds, ether compounds, and complexes with various olefins. Is exemplified.

The amount of the platinum-based catalyst is 0.015 to 0.1 in terms of platinum metal based on 100 parts of the component (A).
Part, particularly preferably 0.02 to 0.05 part,
The amount is determined according to reactivity, economy, and desired curing rate. The platinum-based catalyst is usually used in an amount of 0.01 part or less, but is applied to a substrate having poor heat resistance, such as a plastic film substrate, and cured at a low temperature for a short time to form an organopolysiloxane. In order to improve the adhesion between the cured film obtained by curing the composition and the base material, the amount is 0.015 parts or more.

The organopolysiloxane composition of the present invention can be obtained by uniformly mixing a predetermined amount of the above-mentioned components (A) to (D). Photopolymerization initiators, inorganic fillers such as silica and colloidal silica, pigments, and the like can be added as long as the effects of the present invention are not impaired.

In actually using the composition of the present invention,
For example, the composition prepared as described above may be used as it is.
Alternatively, if necessary, use an organic solvent such as toluene or xylene.
After dilution with the agent, roll coat, reverse coat or
Use a coating method such as gravure coating to apply 0.0
5-5g / m^Two And at 70-170 ° C for 5
Heat for 60 seconds and / or UV (e.g. 80 W / cm
(Using two ultraviolet lamps) for 0.1 to 2 seconds
With excellent adhesion to the substrate and easy removal of adhesive substances
A releasable cured film can be obtained.

Examples of the substrate on which the composition of the present invention is applied include OPP and PET films. The substrate adheres well to these substrates by curing at 100 ° C. for about 10 seconds. is there.

[0030]

The organopolysiloxane composition of the present invention provides a cured product having excellent adhesion to a substrate made of paper, processed paper, or plastic film even when cured at a low temperature and in a short time. Excellent performance for release paper.

[0031]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples. Prior to the description of the examples, a synthesis example of the organopolysiloxane of the component (C) will be described. In addition,
The viscosity in each example is a value at 25 ° C.

[Synthesis Example 1] Allyl glycidyl ether 4
5.6 g, 14.8 g of vinyltrimethoxysilane, and 0.1 g of a 2% butanol solution of chloroplatinic acid were charged into a glass flask, and the temperature was raised to 70 ° C. with stirring, and represented by the following average composition formula (4). 12.1 g of methyl hydrogen polysiloxane was added dropwise over 3 hours.

[0033]

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The solution is heated at 80 ° C. for 5 hours, then cooled and treated with activated carbon to obtain a reaction mixture, and then the solvent and low-boiling substances are removed from the reaction mixture under reduced pressure. , The following average composition formula (5)
And 65.2 g of a linear organopolysiloxane having a hydrogen atom directly bonded to a silicon atom, an epoxy group and an alkoxysilyl group in the molecule was obtained.

[0035]

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[Synthesis Example 2] The above formula (5) obtained in Synthesis Example 1
181 g of organopolysiloxane and 300 g of toluene
Was charged into a glass flask and heated to 70 ° C., and then 13 g of acrylic acid and 1.8 g of potassium acrylate were added dropwise over 4 hours. After completion of the addition, the mixture was stirred for 1 hour while maintaining the temperature at 70 ° C. Then, after washing the reaction product with water,
The solvent was distilled off under reduced pressure to obtain 175 g of an organopolysiloxane represented by the following average composition formula (6).

[0037]

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[Synthesis Example 3] 137.8 g of an acrylic group-containing cyclosiloxane represented by the following formula (7) and tetramethylcyclotetrasiloxane [(CH ₃ ) HSiO] ₄ 16
8.4 g and 32.4 g of hexamethyldisiloxane were mixed, 0.58 g of trifluoromethanesulfonic acid was added, and polymerization was carried out at 80 ° C. for 6 hours.

[0039]

Embedded image (Mixture of n = 3, 4, 5)

After the completion of the polymerization reaction, 3.0 g of sodium hydrogencarbonate was added and neutralized at 100 ° C. for 2 hours. After allowing to cool, the mixture was filtered, and volatile components were distilled off under reduced pressure under heating to obtain 288 g of a compound represented by the following formula (8).

[0041]

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Next, vinyl trimethoxysilane 14.8
g, a mixed solution of 0.2 g of a 2% butanol solution of chloroplatinic acid and 90 g of toluene was prepared.
While stirring with, 169 g of the compound of the above formula (8) was added dropwise over 3 hours. Further heated at 80 ° C for 5 hours, cooled,
After the activated carbon treatment, the solvent was heated under reduced pressure from the reaction mixture,
Volatile components are distilled off, and a hydrogen atom represented by the following average composition formula (9) and directly bonded to a silicon atom in the molecule, an acrylic group,
175 g of a linear organopolysiloxane having an alkoxysilyl group was obtained.

[0043]

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Example 1 α, ω-bis (trimethylsilyl) having the following average composition formula (10) and having a viscosity of 1000 cs at 25 ° C. and a clogged dimethylpolysiloxane having both ends of a trivinyl group at 100 cs and a viscosity of 40 cs. 7 g of polymethyl hydrogen polysiloxane, 3 g of the compound of the above formula (5) obtained in the above synthesis example, 4 g of chloroplatinic acid-olefin complex (0.02 g as platinum amount),
Acetylene alcohol (1.0 g) was mixed until uniform, to obtain a peelable organopolysiloxane composition.

[0045]

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Next, using an offset printing machine,
About 0.5 g / m^Two OPP filter
And heat-treated at 100 ° C for 10 seconds
Then, when the above composition was cured, the OPP film and
A cured film having good adhesion was obtained.

In place of the heat treatment, 80 W / c
m, using two ultraviolet lamps, irradiating with ultraviolet light for 0.8 seconds,
When a cured silicone film was formed on the OPP film, the cured film also had good adhesion to the OPP film as described above.

The composition is obtained by the above-mentioned heat curing and ultraviolet curing.
Lumilar 31B tape (Nitto Denko Corporation)
Manufactured), temperature 70 ° C, pressure 20g / cm^Two 1 day pressure
After attaching, the peeling force was measured at a peeling speed of 0.3 m / min.
However, both are 6g / 2.5cm,
It peeled off easily.

[Comparative Example] In Example 1, the above formula (5) was used.
A composition was prepared in the same manner as in Example 1 except that the organopolysiloxane was not blended, and a cured film was formed by heat curing and ultraviolet curing in the same manner as in Example 1. By rubbing with a finger about 10 times, it was easily removed from the substrate, and the adhesion was poor.

Example 2 A composition was prepared in the same manner as in Example 1 except that the compound of Formula (6) obtained in Synthesis Example 2 was used instead of the compound of Formula (5). It was prepared and applied and cured in the same manner using the same base material as in Example 1. As a result, a cured film having good adhesion to the OPP film was obtained both in the case of curing by heating and in the case of curing by ultraviolet rays.

The peeling force of the Lumirror 31B tape in the same manner as in Example 1 was 10 g / 2.5 cm for both heat curing and ultraviolet curing, and the adhesive substance was easily peeled off.

Example 3 Synthesis Example 3 in Example 1 instead of the compound of the formula (5)
A composition was prepared in the same manner as in Example 1 except that the compound of the above formula (9) obtained in was blended, and was applied and cured in the same manner using the same base material as in Example 1. In both the case of curing by UV irradiation and the case of curing by UV light, a cured film adhered well to the OPP film was obtained.

The peeling force of the Lumirror 31B tape performed in the same manner as in Example 1 was 9 g / 2.5 cm for both heat curing and ultraviolet curing, and the adhesive substance was easily peeled off.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08L 63:00) (72) Inventor Akinari Itagaki 1-chome, Hitomi, Matsuida-cho, Usui-gun, Gunma Prefecture 10 Silicon Electronics (56) References JP-A-4-36354 (JP, A) JP-A-4-31441 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 83 / 07 C08G 77/20 C09J 7/02

Claims (4)

(57) [Claims] 1. A release organopolysiloxane composition for release paper, which is applied and cured on a substrate made of general paper, processed paper or plastic film, and has an adhesive substance adhered on the cured film. (A) a vinyl group-containing organopolysiloxane having at least two vinyl groups directly bonded to silicon atoms in one molecule: 100 parts by weight; (B) a hydrogen atom directly bonded to silicon atoms in one molecule An organo having at least two organic groups other than a hydrogen atom directly bonded to a silicon atom, wherein the organic group is an alkyl group, an aryl group, an aralkyl group, or a group in which part or all of the hydrogen atoms of these groups are substituted with halogen atoms. Hydrogen polysiloxane: 0.1 to 20 parts by weight, in which the molar ratio of HSiＨ to the vinyl group of component (A) is in the range of 0.5 to 10, (C) 1 In the molecule, an acryl group, a methacryl group, and / or an epoxy group bonded to a silicon atom via an alkylene group, a hydrogen atom directly bonded to a silicon atom, and an alkoxysilyl group bonded via an alkylene group, respectively. Having at least one of the following:
0.1 to 20 parts by weight, (D) a platinum-based catalyst: a peelable organopolysiloxane composition comprising 0.015 to 0.1 part by weight as platinum. 2. The composition according to claim 1, wherein the component (C) is represented by the following general formula (2) or (3). Embedded image (Provided that R ¹ is a substituted or unsubstituted monovalent hydrocarbon group containing no aliphatic unsaturated bond, R ² is an acryl group-containing alkylene group, a methacryl group-containing alkylene group or an epoxy group-containing alkylene group, and R ³ is an alkoxy group. Represents a silyl group-containing alkylene group, wherein t and x are integers of 0 or more, s, u, v,
w, y, and z are integers of 1 or more. ) 3. The composition according to claim 1, wherein the component (A) is represented by the following formula (1). Embedded image (However, R ¹ is a substituted or unsubstituted monovalent hydrocarbon group containing no aliphatic unsaturated bond, m is from 0 to 100, and n is from 100 to
It is an integer of 8000. ) 4. A release paper in which a cured film of the releasable organopolysiloxane composition according to claim 1, 2, or 3 is formed on a substrate made of general paper, processed paper or plastic film.