JP4523777B2 - Release sheet - Google Patents

Description

  The present invention relates to a release sheet. More specifically, the present invention relates to a release sheet that is non-silicone release agent and has good release properties from the pressure-sensitive adhesive layer, and is suitably used for applications related to precision electronic equipment. is there.

  In recent years, pressure-sensitive adhesive sheets have been used in various stages and types of manufacturing processes for precision electronic devices such as ceramic capacitors, hard disk drives, and semiconductor devices.

In such a pressure sensitive adhesive sheet used in the manufacturing process of precision electronic equipment, the silicone pressure sensitive adhesive may cause trouble with electronic components due to the low molecular weight silicone compound contained in the pressure sensitive adhesive. Non-silicone adhesives such as acrylic adhesives, polyester adhesives, urethane adhesives and the like are used.
In order to protect the pressure-sensitive adhesive layer until use, this pressure-sensitive adhesive sheet is laminated with a release sheet having a release agent layer provided on a substrate.

In the release sheet layer of the release sheet, a silicone release agent is often used for general use. When a silicone release agent is used for the above-mentioned use, a low molecular weight silicone contained in the silicone release agent is used. The compound migrates and remains in the pressure-sensitive adhesive layer, and there is a possibility that the electronic component may cause a trouble in the same manner as the silicone-based pressure-sensitive adhesive described above.
Therefore, the release agent layer of the release sheet used for the above-mentioned application has an alkyd resin known as a non-silicone release agent (for example, see Patent Document 1) or a long-chain alkyl resin (for example, Patent Document 1). 2) has been attempted.

However, when these resins are used in the release agent layer, there is a problem that the release force from the adhesive layer is high and the adhesive layer and the release agent layer may not be released.
On the other hand, a release agent composition based on a polybutadiene rubber having a specific property, which has been proposed as an excellent release agent for silicone-based adhesives (see, for example, Patent Document 3), is used for non-silicone-based adhesives. However, when the release sheet is peeled off from the pressure-sensitive adhesive layer, the release agent layer and the base material are peeled off, There is a possibility of remaining on the adhesive layer.

Japanese Unexamined Patent Publication No. 57-49585 JP 2002-249757 A JP-A-4-45135

  Under such circumstances, the present invention provides a release sheet in which the release agent is non-silicone, has good release properties from the pressure-sensitive adhesive layer, and has excellent adhesion between the release agent layer and the substrate. It is intended to do.

As a result of intensive studies to achieve the above object, the present inventors have a specific proportion of polybutadiene having mainly 1,4 bond units, and a hydroxyl group which is a copolycondensation polymer of polyol and polycarboxylic acid. It was found that the purpose can be achieved by using a release agent composition containing a saturated polyester resin and a crosslinking agent in the release agent layer.
The present invention has been completed based on such findings.
That is, the present invention
(1) On the substrate, 35-99% by weight of 1,4-polybutadiene as the solid content, and 1-65% by weight of polyol and polycarboxylic acid as the solid content Provided with a release agent layer formed by coating and curing a solution of a release agent composition containing a saturated polyester resin having a hydroxyl group as a coalescence and a content of 0.1 to 50% by weight of a crosslinking agent as a solid content Release sheet, characterized by
(2) The release sheet of (1) above, wherein the release agent composition solution further contains an acid catalyst,
(3) The release sheet according to (1) or (2), wherein the crosslinking agent is an isocyanate-based crosslinking agent ,
( 4) The release sheet according to any one of (1) to (3), wherein the release agent layer has a thickness of 0.01 to 1.0 μm ,
(5) The base material is any one of the above (1) to (4), wherein the base material is any one of a paper base material, a laminated paper obtained by laminating a thermoplastic resin to the paper base material, a plastic film, and a laminated sheet including these. Release sheet, and
(6) The polyol is any one selected from aliphatic diols, alicyclic diols and aromatic diols, and the polycarboxylic acid is any one selected from aliphatic dicarboxylic acids, alicyclic dicarboxylic acids and aromatic dicarboxylic acids. The release sheet according to any one of (1) to (5) is provided.

  The peeling force between the release agent layer and the pressure-sensitive adhesive layer of the release sheet of the present invention is 1000 mN / 20 mm or less. Moreover, it is excellent also in the adhesiveness of the release agent layer of a peeling sheet and a base material.

  The release agent composition used for the release agent layer of the release sheet of the present invention (hereinafter sometimes referred to as “the release agent composition of the present invention”) is 35 to 99% by weight as the solid content. It contains 1,4-polybutadiene, a saturated polyester resin having a hydroxyl group of 1 to 65% by weight as a solid content, and a crosslinking agent of 0.1 to 50% by weight as a solid content.

In the release agent composition of the present invention, 1,4-polybutadiene is a polybutadiene composed of only 1,4-bonds other than 1,2-bonds inevitably generated during polymerization.
Further, 1,4-polybutadiene may have either a cis structure or a trans structure, and those having an arbitrary cis content can be used.

  The content of the 1,4-polybutadiene in the release agent composition is required to be 35 to 99% by weight, particularly 40 to 95% by weight as the solid content. When this content is less than 35% by weight, good peeling performance cannot be obtained, and when it exceeds 99% by weight, the adhesion between the release sheet substrate and the release agent layer is deteriorated.

  In the release agent composition of the present invention, the saturated polyester resin having a hydroxyl group is not particularly limited as long as it has two or more functional groups such as a hydroxyl group in one molecule and is soluble in a solvent. The saturated polyester resin having a hydroxyl group is preferably a copolycondensation polymer of a polyol and a polycarboxylic acid, and the polyol is preferably an aliphatic diol, an alicyclic diol, or an aromatic diol, and the polycarboxylic acid is an aliphatic diol. Aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and aromatic dicarboxylic acids are preferred. The saturated polyester resin having a hydroxyl group may be a modified product of a saturated polyester resin having a hydroxyl group.

  The content of the saturated polyester resin having a hydroxyl group in the release agent composition is required to be 1 to 65% by weight as the content in the solid content, and particularly preferably 5 to 60% by weight. . When the content is less than 1% by weight, the adhesion between the release sheet substrate and the release agent layer is deteriorated, and when it exceeds 65% by weight, good release performance cannot be obtained.

In the release agent composition of the present invention, the crosslinking agent is not particularly limited. For example, an isocyanate compound, an epoxy compound, a melamine compound, an aziridine compound, a hydrazide compound, an oxazoline compound, a carbodiimide compound, urea Compounds, dialdehyde compounds, metal chelate compounds, metal alkoxides, metal salts and the like. These may be used alone or in combination of two or more.
The content of the crosslinking agent in the release agent composition is required to be 0.1 to 50% by weight, and particularly preferably 0.5 to 40% by weight as the solid content. When the content is less than 0.1% by weight, the adhesion between the release sheet substrate and the release agent layer is deteriorated, and when it exceeds 50% by weight, good release performance cannot be obtained.

In the release agent composition of the present invention, an acidic catalyst can be used. Adhesiveness with a base material improves by using an acidic catalyst.
The acidic catalyst is not particularly limited and can be appropriately selected from conventionally known acidic catalysts. As such an acidic catalyst, for example, an organic acidic catalyst such as p-toluenesulfonic acid and methanesulfonic acid is suitable.
This acidic catalyst may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, the usage-amount is normally selected in the range of 0.1-20 weight part with respect to 100 weight part of solid content in a release agent composition.

The release agent composition of the present invention is usually used in the form of an organic solvent solution for convenience in use.
The organic solvent used in this case can be appropriately selected from known solvents having good solubility in the polybutadiene and saturated polyester resin having a hydroxyl group. Examples of such a solvent include toluene, xylene, methanol, ethanol, isobutanol, n-butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. These may be used individually by 1 type, and may be used in combination of 2 or more types.

Next, the release sheet of the present invention will be described.
The release sheet of the present invention is provided with a release agent layer made of the aforementioned release agent composition on a substrate, and is used for applications related to precision electronic equipment.
There is no restriction | limiting in particular as a base material in this release sheet, It can select suitably from well-known base materials conventionally known as a base material of a release sheet. Examples of such base materials include paper base materials such as glassine paper, coated paper, cast coated paper, and dust-free paper, laminated paper obtained by laminating a thermoplastic resin such as polyethylene on these paper base materials, polyethylene terephthalate, Examples thereof include polyester films such as butylene terephthalate and polyethylene naphthalate, polyolefin films such as polypropylene and polymethylpentene, plastic films such as polycarbonate films and cellulose acetate films, and laminated sheets containing these. Although there is no restriction | limiting in particular as thickness of this base material, Usually, 10-150 micrometers is desirable.

  When using a plastic film as the base material, an oxidation method is optionally applied to the surface of the plastic film on which the release agent layer is provided, for the purpose of improving the adhesion between the plastic film and the release agent layer. Or a physical or chemical surface treatment such as an uneven method. Examples of the oxidation method include corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment and the like, and examples of the concavo-convex method include a sand blast method and a solvent treatment method. . These surface treatment methods are appropriately selected according to the type of the substrate, but in general, the corona discharge treatment method is preferably used from the viewpoints of effects and operability. Moreover, primer treatment can also be performed.

On the substrate, for example, a bar coating method, a reverse roll coating method, a knife coating method, a roll knife coating method, a gravure coating method, an air doctor coating method, a doctor blade coating method, etc. The release agent layer can be formed by applying the solution of the release agent composition of the present invention, heating at a temperature of about 80 to 150 ° C., and curing.
The amount of the solution of the release agent composition to be applied is preferably such that the thickness of the release agent layer after curing is in the range of 0.01 to 1.0 μm. If the thickness of the release agent layer is less than 0.01 μm, the coating property may not be stable, and a uniform coating film may not be obtained. If the thickness exceeds 1.0 μm, the adhesion of the release agent layer to the substrate may occur. , Curability and the like may be reduced. A more preferable thickness of the release agent layer is in the range of 0.02 to 0.5 μm.

  There is no restriction | limiting in particular as an adhesive applied to the peeling sheet of this invention, For example, it can select suitably from conventionally well-known adhesives, such as an acrylic adhesive, a polyester adhesive, and a urethane type adhesive, for example. .

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, in description of an Example and a comparative example,% means solid content weight%, A part means a weight part.

Example 1
(1) Formation of release agent layer 1,4-polybutadiene (Hicis 1,4-polybutadiene, trade name: BR-10, manufactured by JSR) was dissolved in a 1: 1 (weight ratio) mixed solvent of toluene and methyl ethyl ketone. A 1% solution was obtained.
A 30% solution of a saturated polyester resin having a hydroxyl group (manufactured by Dainippon Ink & Chemicals, trade name: HOF-862) is diluted with a 1: 1 (quantity ratio) solvent mixture of toluene and methyl ethyl ketone, and 1% It adjusted so that it might become a solution.
A 65% solution of toluene diisocyanate-containing urethane prepolymer (Dainippon Ink Chemical Co., Ltd., trade name: CRISVON NX), which is an isocyanate crosslinking agent, is diluted with a 1: 1 (weight ratio) mixed solvent of toluene and methyl ethyl ketone. It adjusted so that it might become a 1% solution.
Next, 70 parts of a 1% solution of 1,4-polybutadiene, 28.5 parts of a 1% solution of a saturated polyester resin having a hydroxyl group, and 1.5 parts of a 1% solution of a toluene preisocyanate-containing urethane prepolymer are mixed, and further an acid catalyst. As a result, 0.001 part of p-toluenesulfonic acid 50% solution (trade name: Dryer 900, manufactured by Hitachi Chemical Co., Ltd.) was added to prepare a release agent composition.
The release agent composition was applied to the surface of a 38 μm-thick polyethylene terephthalate (PET) film (Mitsubishi Chemical Polyester Film Co., Ltd., trade name: Diafoil T100-38) with Mayer Bar # 4, and then 150 The sheet was heated and dried at 1 ° C. for 1 minute, and further allowed to stand at 70 ° C. for 1 day to prepare a sheet having a release agent layer having a thickness of 0.08 μm.

(2) Formation of pressure-sensitive adhesive layer An acrylic pressure-sensitive adhesive (trade name: PL Thin, manufactured by Lintec Co., Ltd.) was used for a polyethylene terephthalate (PET) film having a thickness of 50 μm [trade name: Lumirror E20 # 50 white] manufactured by Toray Industries, Inc. The surface was coated with an applicator, heated at 110 ° C. for 1 minute and dried to prepare a sheet having a pressure-sensitive adhesive layer having a thickness of 20 μm.

(3) Measurement of silicone amount The silicone amount of the release agent layer of the sheet obtained in (1) above was measured by X-ray photoelectron spectroscopy (XPS) under the following conditions.
Measuring device: ESCA 5600 manufactured by PerkinElmer
X-ray source: Mg standard (15 KV, 400 W)
Extraction angle: 45 degrees Measurement time: 3 minutes Measurement elements: silicon (Si) and carbon (C)
The amount of Si was expressed as “%” by multiplying the value of Si / (Si + C) by 100.
The results are listed in Table 1.

(4) Measurement of peel force The sheet obtained in (1) above and the sheet obtained in (2) above are overlaid so that the release agent layer and the pressure-sensitive adhesive layer are in contact with each other, and 23 ° C. and 50% RH. After leaving for 1 day or 7 days in the atmosphere, the release force of each release agent layer is 180 ° direction using a tensile tester in an atmosphere of 23 ° C. and 50% RH in accordance with JIS-Z0237. Was peeled off at a speed of 300 mm / min.
The results are listed in Table 1.

(5) Measurement of adhesion between the release agent layer and the base material The surface of the release agent layer is rubbed with a finger, the release agent layer is taken from the base material, and the presence or absence of a desorption phenomenon is visually observed, and determined according to the following criteria. did.
○: The release agent layer is taken from the base material, and no desorption phenomenon is observed.
Δ: The release agent layer is removed from the base material, and a slight desorption phenomenon is observed, but there is no problem in practical use. X: Taken from the base material of the release agent layer, the desorption phenomenon is noticeable, and cannot be used practically.
The results are listed in Table 1.

Example 2
The mixing ratio in the release agent composition was 90 parts of a 1% solution of 1,4-polybutadiene, 9.5 parts of a 1% solution of a saturated polyester resin having a hydroxyl group, and 0.5% of a 1% solution of a toluene diisocyanate-containing urethane prepolymer. The evaluation was performed and evaluated in exactly the same manner as in Example 1 except that the part was used.
The results are listed in Table 1.

Example 3
The mixing ratio in the release agent composition was 50 parts of a 1% solution of 1,4-polybutadiene, 47.5 parts of a 1% solution of a saturated polyester resin having a hydroxyl group, and a 2.5% 1% solution of a toluene diisocyanate-containing urethane prepolymer. The evaluation was performed and evaluated in exactly the same manner as in Example 1 except that the part was used.
The results are listed in Table 1.

Example 4
The mixing ratio in the release agent composition was 40 parts of a 1% solution of 1,4-polybutadiene, 57 parts of a 1% solution of a saturated polyester resin having a hydroxyl group and 3 parts of a 1% solution of a toluene preisocyanate-containing urethane prepolymer. Was carried out and evaluated in exactly the same manner as in Example 1.
The results are listed in Table 1.

Example 5
The mixing ratio in the release agent composition was set to 70 parts of a 1% solution of 1,4-polybutadiene, 15 parts of a 1% solution of a saturated polyester resin having a hydroxyl group and 15 parts of a 1% solution of a toluene diisocyanate-containing urethane prepolymer. Was carried out and evaluated in exactly the same manner as in Example 1.
The results are listed in Table 1.

Example 6
The evaluation was performed in the same manner as in Example 1 except that the acid catalyst (p-toluenesulfonic acid) was not used.
The results are listed in Table 1.

Example 7
The evaluation was carried out in the same manner as in Example 1 except that the toluene diisocyanate-containing urethane prepolymer was replaced with the same weight of toluene diisocyanate (trade name: Coronate L, manufactured by Nippon Polyurethane Co., Ltd.).
The results are listed in Table 1.

Comparative Example 1
Except that the release agent composition consisted only of a 1% solution of 1,4-polybutadiene and no acid catalyst was used, it was carried out and evaluated in exactly the same manner as in Example 1.
The results are listed in Table 1.

Comparative Example 2
The mixing ratio in the release agent composition was 30 parts of a 1% solution of 1,4-polybutadiene, 66.5 parts of a 1% solution of a saturated polyester resin having a hydroxyl group, and a 1% solution of a toluene preisocyanate-containing urethane prepolymer 3.5. The evaluation was performed and evaluated in exactly the same manner as in Example 1 except that the part was used.
The results are listed in Table 1.

Comparative Example 3
The release agent composition was diluted with toluene in 100 parts of a silicone release agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KS-847H) and 1 part of a catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: CAT-PL-50T). Except that it was made into a solution with a solid content of 1.1%, and after applying the release agent composition, it was heated at 130 ° C. for 1 minute, dried and cured, and was completely the same as Example 1. Conducted and evaluated.
The results are listed in Table 1.

  The release sheet of the present invention is not a silicone-based release sheet that adversely affects the electronic component when used in the field of mounting electronic components, but is a release sheet with good release properties from the adhesive layer, It is possible to provide an adhesive laminate that is suitably used for applications related to precision electronic devices such as mounting of components and assembly of a magnetic recording device (HDD).

Claims (6)

On the base material, it is a copolycondensation product of 35 to 99% by weight of 1,4-polybutadiene as the solid content, and 1 to 65% by weight of polyol and polycarboxylic acid as the solid content. Provided with a release agent layer formed by coating and curing a solution of a release agent composition containing a saturated polyester resin having a hydroxyl group and a content of 0.1 to 50% by weight of a crosslinking agent as a solid content. A release sheet.   The release sheet according to claim 1, wherein the release agent composition solution further contains an acid catalyst.   The release sheet according to claim 1 or 2, wherein the crosslinking agent is an isocyanate-based crosslinking agent.   The release sheet according to claim 1, wherein the release agent layer has a thickness of 0.01 to 1.0 μm. The release sheet according to any one of claims 1 to 4, wherein the base material is any one of a paper base material, a laminated paper obtained by laminating a thermoplastic resin to the paper base material, a plastic film, and a laminated sheet including these. The polyol is any one selected from aliphatic diols, alicyclic diols and aromatic diols, and the polycarboxylic acid is any one selected from aliphatic dicarboxylic acids, alicyclic dicarboxylic acids and aromatic dicarboxylic acids. The release sheet according to any one of 5.