WO2022004418A1 - Release sheet - Google Patents

Abstract

[Problem] To provide a release sheet which has a low peeling force at normal temperature, can suppress a decrease in residual adhesion rate, exhibits good release properties even after a high temperature heating step, and exhibits excellent release agent layer strength. [Solution] Provided is a release sheet that is characterized by: having a substrate sheet and a release agent layer formed on at least one surface of the substrate sheet; the release agent layer being formed from an aminoalkyd resin composition containing a (meth)acrylic block copolymer; and the (meth)acrylic block copolymer having a block A having a structural unit (a-1) represented by general formula (1) and a block B having a structural unit (b-1) derived from a (meth)acrylic monomer having a reactive functional group. [In formula (1), R¹¹ denotes an alkyl group having 12-28 carbon atoms. R¹² denotes a hydrogen atom or a methyl group.]

Description

Release sheet

The present invention relates to a mold release sheet.

Electronic components such as semiconductors, various connectors, capacitors, resistors, and printed wiring boards are widely used in various products. In the process of assembling these parts, an adhesive tape or a sheet-like adhesive is used for joining or temporarily fixing the parts. For adhesive tapes and sheet-like adhesives, it is common to place a release sheet on the adhesive surface or the adhesive surface in order to protect the adhesive surface or the adhesive surface during storage.

In such a mold release sheet, the surface in contact with the adhesive or the adhesive is subjected to a mold release treatment to facilitate peeling from the adhesive or the adhesive. As the mold release treatment, a mold release agent such as silicone-based, fluorine-based, long-chain alkyl-based, wax-based, and polyolefin-based is used.

However, since the silicone component of the silicone release agent is easily transferred to the mold release body, when it is used for joining electronic parts or temporarily fixing electronic parts in the manufacturing process, the electronic parts are liable to malfunction. There's a problem. Therefore, it has been proposed to use a non-silicone mold release agent (a mold release agent that does not contain a silicone compound) such as a polyolefin-based mold release agent and a long-chain alkyl-based mold release agent for such applications.

For example, Patent Document 1 discloses a method of using a non-silicone-based release agent as a release treatment agent for release paper in a packaging structure of a semiconductor chip in which a semiconductor chip is sandwiched between an adhesive tape and a release paper. See Document 1 (Claim 1, paragraph 0021)). Further, Patent Document 2 discloses an adhesive film with a separator used for a flexible printed wiring board, which uses an alkyd resin-based mold release agent as a release agent for the separator (Patent Document 2). 2 (see claim 1, paragraph 0009)).

Japanese Unexamined Patent Publication No. 2009-196657 Japanese Unexamined Patent Publication No. 2009-73971

In recent years, in the process of forming an interphase insulating film of a printed wiring board, a method of forming a sheet-like adhesive on a release sheet and transferring it to an adherend such as a printed wiring board by a hot press has become widespread. Further, by raising the boiling point of the solvent used in the step of forming the sheet-shaped adhesive, the drying temperature for removing the solvent is also raised. Further, solder reflow heating following the heat pressing process is also performed with the release sheet attached. Therefore, the release sheet is required to have heat resistance that can maintain a low peeling force even when exposed to a high temperature atmosphere.

However, the heat resistance of the conventional non-silicone mold release sheet has not been examined at all. Therefore, the conventional non-silicone release sheet has a problem that when it is exposed to a high temperature atmosphere in contact with an adhesive or an adhesive, the release force increases and it cannot be easily removed from the adhesive or the adhesive. rice field.

The present invention has been made in view of the above circumstances, has a small peeling force at room temperature, can suppress a decrease in the residual adhesive rate, has good peeling property even after a high temperature heating step, and is a mold release agent. It is an object of the present invention to provide a release sheet having excellent layer strength.

The release sheet of the present invention that has been able to solve the above problems has a base sheet and a release agent layer formed on at least one surface of the base sheet, and the release agent layer is formed. It is formed from an aminoalkido resin composition containing a (meth) acrylic block copolymer, and the (meth) acrylic block copolymer is a structural unit (a-1) represented by the general formula (1). ), And a block copolymer having a B block having a structural unit (b-1) derived from a (meth) acrylic monomer having a reactive functional group.

[In the formula (1), R ¹¹ represents an alkyl group having 12 to 28 carbon atoms. R ¹² represents a hydrogen atom or a methyl group. ]

The release sheet of the present invention has a small peeling force at room temperature, can suppress a decrease in the residual adhesive rate, has good peelability even after a high temperature heating step, and has excellent strength of the release agent layer.

The release sheet according to the present invention has a base sheet and a release agent layer formed on at least one surface of the base sheet, and the release agent layer has a (meth) acrylic block co-weight. The (meth) acrylic block copolymer, which is formed from an aminoalkido resin composition containing a coalescence, reacts with the A block having the structural unit (a-1) represented by the general formula (1). It is a block copolymer having a B block having a structural unit (b-1) derived from a (meth) acrylic monomer having a sex functional group. The release sheet has good peelability even when the release agent layer undergoes a heating step (for example, heating at 100 ° C. or higher), and the components of the release agent layer are difficult to transfer to the adherend and are released. The strength of the mold layer is excellent. Further, in the mold release sheet according to the present invention, since the mold release agent layer does not substantially contain a silicone compound, it is possible to suppress defects that occur in the electronic parts and the manufacturing process of the electronic parts.

In the present invention, the "vinyl monomer" refers to a monomer having a carbon-carbon double bond capable of radical polymerization in the molecule. The "structural unit derived from a vinyl monomer" means a structural unit obtained by polymerizing a radically polymerizable carbon-carbon double bond of a vinyl monomer into a carbon-carbon single bond. "(Meta) acrylic" means "at least one of acrylic and methacryl". "(Meta) acrylate" means "at least one of acrylate and methacrylate".

Hereinafter, the present invention will be described in detail.

<Release sheet>
The release sheet of the present invention has a base sheet and a release agent layer formed on at least one surface of the base sheet, and the release agent layer is a (meth) acrylic block copolymer. It is formed from an aminoalkyd resin composition containing.

The aminoalkyd resin composition contains a constituent component of the aminoalkyd resin and a (meth) acrylic block copolymer (hereinafter, may be simply referred to as "block copolymer").

(Constituents of aminoalkyd resin)
The constituent component of the aminoalkyd resin contained in the aminoalkyd resin composition is a component constituting the aminoalkyd resin when the aminoalkyd resin composition is applied and cured. Specific examples thereof include alkyd resins and amino resins. Further, as the aminoalkyd resin component, a prepolymerized aminoalkyd resin may be used.

The alkyd resin is a condensate of a polybasic acid and a polyhydric alcohol. In the alkyd resin, a condensate of a polybasic acid and a polyhydric alcohol may be modified with a denaturing agent such as fatty oil or fatty acid.

Examples of the polybasic acid include saturated polybasic acids such as phthalic anhydride, terephthalic acid, succinic acid, adipic acid and sebacic acid; and unsaturated polyusic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid and citraconic anhydride. Basic acid; other polybasic acids such as cyclopentadiene-maleic anhydride adduct, terpene-maleic anhydride adduct, rosin-maleic anhydride adduct, and the like. The polybasic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol and neopentyl glycol; and trihydric alcohols such as glycerin, trimethylolethane and trimethylolpropane. Examples thereof include tetrahydric or higher polyhydric alcohols such as diglycerin, triglycerin, pentaerythritol, pentaerythrit, dipentaerytrit, mannit, and sorbit. The polyhydric alcohol may be used alone or in combination of two or more.

Examples of the modifier include fatty oils such as soybean oil, flaxseed oil, millet oil, castor oil, dehydrated castor oil and palm oil, and fatty acids thereof; stearic acid, oleic acid, linoleic acid, linoleic acid and eleostearic acid. , Fats and oils such as ricinoleic acid and dehydrated ricinoleic acid and fatty acids; natural resins such as rosin, koval, kohaku and serrac; synthetic resins such as ester gum, phenolic resin, urea resin and melamine resin. The modifier may be used alone or in combination of two or more.

The alkyd resin preferably has a long-chain alkyl group. The number of carbon atoms of the long-chain alkyl group is preferably 12 or more, more preferably 14 or more, still more preferably 16 or more, from the viewpoint of detachability from the adherend. Further, from the viewpoint of availability and handleability of the raw material, the carbon number of the long-chain alkyl group is preferably 28 or less, more preferably 26 or less, still more preferably 22 or less.

The acid value of the alkyd resin is preferably 2 mgKOH / g to 30 mgKOH / g, preferably 4 mgKOH / g to 25 mgKOH / g, and more preferably 6 mgKOH / g to 12 mgKOH / g. The hydroxyl value of the alkyd resin is preferably 50 mgKOH / g to 300 mgKOH / g, preferably 80 mgKOH / g to 270 mgKOH / g, and more preferably 100 mgKOH / g to 250 mgKOH / g. By setting the acid value and the hydroxyl value in this range, a cured product having excellent heat resistance and strength can be obtained.

The amino resin is a resin obtained by a condensation reaction between a compound containing an amino group and an aldehyde. Examples of the amino resin include aniline aldehyde resin, urea resin, melamine resin and the like, and melamine resin is preferable. The amino resin has an N-methylol group and / or an N-alkoxymethylol group.

Melamine resin is a general term for compounds in which the amino group of melamine is modified in various ways, and includes those in which a plurality of triazine rings are condensed. As the type of modification, a methylolated melamine compound in which at least one of the hydrogen atoms of the three amino groups is methylolated is preferable, and the methylol group of the methylolated melamine compound is partially or partially composed of a lower alcohol having 1 to 4 carbon atoms. Fully etherified alkyl etherified melamine compounds are preferred.

Commercially available products may be used as the constituent components of the aminoalkyd resin. Examples of commercially available products of the constituent components of the aminoalkyd resin include Tessfine (registered trademark) 303, 305, 314 manufactured by Hitachi Kasei Co., Ltd.

Further, an amino resin may be further added as the aminoalkyd resin component. Examples of commercially available products of the amino resin include Nicarac (registered trademark) MW-30M, Nicarac MW-30, Nicarac MW-22, Nicarac MS-11, Nicarac MS-001, and Nicarac MX-730 manufactured by Mitsui Chemicals. Nicarac MX-750, Nicarak MX-708, Nicarak MX-706, Nicarak MX-035, Nicarak MW-30LF, Nicarak MW-30MLF, Nicarak MW-33LF, Nicarak MZ-351, Nicarak N-0503, Nicarak N-0504; DIC's Amidia® J-820-60, Amidia L-109-65, Amidia L-117-60, Amidia L-125-60, Amidia L-127-60, Amidia L-150-60, Amidia L-166-608, Amidia L-166-608; ETERMINO 9211-60-5, ETERMINO 9212-70, ETERMINO 9215-70, ETERMINO 9216-60-1, ETERMINO 9223-60, ETERMINO 9224-60 manufactured by Changxing Materials Industry. , ETERMINO 9226-60, ETERMINO 9229-60; Mitsui Chemicals' Uban (registered trademark) 10S60, Uban 10R, Uban 20SB, Uban 20SE60, Uban 21R, Uban 22R, Uban 122, Uban 125, Uban 128, Uban 220, Uban There are 225, Uban 228, Uban 28-60, Uban 2020, Uban 132, Uban 60R, Uban 62, Uban 62E, Uban 360, Uban 165, Uban 166-60, Uban 169, Uban 2061, Uban 80S and the like.

((Meta) acrylic block copolymer)
The (meth) acrylic block copolymer (hereinafter, may be simply referred to as "block copolymer") is an A block having a structural unit (a-1) represented by the general formula (1). , A block copolymer having a B block having a structural unit (b-1) derived from a vinyl monomer having a reactive functional group.

The block copolymer may be a copolymer containing a structural unit derived from a (meth) acrylic monomer as a main component (50% by mass or more), and is a structural unit derived from a vinyl monomer other than the (meth) acrylic monomer. Can be contained. The content of the structural unit derived from the (meth) acrylic monomer in the block copolymer is preferably 80% by mass or more, more preferably 90% by mass or more, and 95% by mass in 100% by mass of the entire copolymer. The above is more preferable. The block copolymer may be composed of only structural units derived from the (meth) acrylic monomer.

The content of the structural unit (a-1) in the block polymer is preferably 40% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more in 100% by mass of the block polymer. It is particularly preferably 95% by mass or more, preferably 99.99% by mass or less, more preferably 99.9% by mass or less, and further preferably 99.5% by mass or less. When the content of the structural unit (a-1) is 40% by mass or more, the peelability is better, and when it is 99.99% by mass or less, the compatibility with the aminoalkyd resin is better.

The content of the structural unit (b-1) in the block copolymer is preferably 0.01% by mass or more, more preferably 0.2% by mass or more, still more preferably 0.2% by mass or more in 100% by mass of the block copolymer. It is 0.5% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less. When the content of the structural unit (b-1) is 0.01% by mass or more, the effect of improving the strength of the exfoliated layer by crosslinking becomes larger, and when it is 20% by mass or less, the increase in viscosity of the aminoalkyd resin composition is suppressed. The coatability is improved, and the appearance of the release agent layer is improved.

The total content of the structural unit (a-1) and the structural unit (b-1) in the block copolymer is preferably 40% by mass or more, more preferably 80% by mass in 100% by mass of the block copolymer. As mentioned above, it is more preferably 90% by mass or more, and particularly preferably 95% by mass or more. The copolymer may be composed of only the structural unit (a-1) and the structural unit (b-1).

The mass ratio ((a-1) / (b-1)) of the structural unit (a-1) and the structural unit (b-1) in the block copolymer is preferably 4 or more, more preferably 5. The above is more preferably 10 or more, preferably 10,000 or less, more preferably 500 or less, still more preferably 200 or less, particularly preferably 100 or less, and most preferably 25 or less. When the mass ratio ((a-1) / (b-1)) is 4 or more, the appearance of the release agent layer is improved while maintaining the peelability, and when it is 10,000 or less, the compatibility with the aminoalkyd resin is good. It is possible to impart the strength of the release agent layer by imparting and cross-linking.

The structure of the block copolymer is preferably a linear block copolymer. Further, the linear block copolymer may have any structure (arrangement), but from the viewpoint of the physical properties of the linear block copolymer or the physical properties of the composition, the A block is A and the B block is B. when expressed as, _{(a-B) m} type, _(a-B) m -A type, _(B-a) m -B type (m is an integer of 1 or more, for example, an integer of 1 to 3) the group consisting of It is preferable that it is a copolymer having at least one structure selected from the above. Among these, AB type diblock copolymers are preferable from the viewpoint of handleability during processing and physical properties of the composition. By constructing the AB type diblock copolymer, the structural unit (a-1) possessed by the A block and the structural unit (b-1) possessed by the B block are localized, and the structure possessed by the A block is localized. The unit (a-1) is efficiently oriented to the air surface (peeling surface) to improve the peelability, and the structural unit (b-1) of the B block is oriented to the base material surface for cross-linking. It is considered that the efficiency is improved and the strength of the release agent layer is improved. The block copolymer may have blocks other than the A block and the B block.

The content of A block is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and 99.99% by mass or less in 100% by mass of the entire block copolymer. It is preferable, more preferably 99.9% by mass or less, still more preferably 99.5% by mass or less.
The content of B block is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.5% by mass or more, and 20% by mass in 100% by mass of the entire block copolymer. It is preferably mass% or less, more preferably 10 mass% or less, still more preferably 5 mass% or less. If the content of the B block is 0.01% by mass or more, the strength of the release agent layer can be sufficient, and if it is 20% by mass or less, the appearance and peeling power of the release agent layer are good. It becomes a thing.

The mass ratio (A block / B block) of A block to B block in the block copolymer is preferably 80/20 or more, more preferably 90/10 or more, still more preferably 95/5 or more. It is preferably 99.99 / 0.01 or less, more preferably 99.9 / 0.1 or less, still more preferably 99.5 / 0.5 or less. When the mass ratio of the A block and the B block is within the above range, the compatibility between the block copolymer and the aminoalkyd resin is high, and the peelability and appearance of the release agent layer are further improved.

The molecular weight of the block copolymer is measured by a gel permeation chromatography (hereinafter referred to as "GPC") method. The weight average molecular weight (Mw) of the block copolymer is preferably 5,000 or more, more preferably 15,000 or more, further preferably 30,000 or more, preferably 400,000 or less, and more preferably 200, It is 000 or less, more preferably 70,000 or less, and particularly preferably 60,000 or less. When the weight average molecular weight is 5,000 or more, the strength of the release agent layer can be sufficient, and when it is 400,000 or less, the solubility in a solvent is good.

The molecular weight distribution (PDI) of the block copolymer is preferably 3.0 or less, more preferably 2.0 or less, still more preferably 1.6 or less, and particularly preferably 1.5 or less. In addition, in this specification, a molecular weight distribution (PDI) is obtained by (weight average molecular weight (Mw) of a copolymer) / (number average molecular weight (Mn) of a copolymer). The smaller the PDI, the narrower the width of the molecular weight distribution, and the copolymer has the same molecular weight. When the value is 1.0, the width of the molecular weight distribution is the narrowest. That is, the lower limit of PDI is 1.0. When the molecular weight distribution (PDI) of the block copolymer exceeds 3.0, those having a small molecular weight and those having a large molecular weight will be included.

The amount of the reactive functional group per 100 g of the block copolymer is preferably 0.05 mmol / 100 g or more, more preferably 0.9 mmol / 100 g or more, still more preferably 1.2 mmol / 100 g or more, and particularly preferably 1.8 mmol. / 100 g or more, most preferably 3.0 mmol / 100 g or more, preferably 120.0 mmol / 100 g or less, more preferably 60.0 mmol / 100 g or less, still more preferably 8.0 mmol / 100 g or less, and particularly preferably 7. It is 0 mmol / 100 g or less, most preferably 4.9 mmol / 100 g or less. When the amount of the reactive functional group is 0.05 mmol / 100 g or more, the strength of the release agent layer can be sufficient, and when it is 120.0 mmol / 100 g or less, a good adherend can be obtained. Peeling power is obtained.

The content of the block copolymer is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 4 parts by mass or more, based on 100 parts by mass of the constituent components of the aminoalkido resin, from the viewpoint of heat resistance. Particularly preferably, it is 7 parts by mass or more, preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and further preferably 35 parts by mass or less. When the content of the block copolymer is 1 part by mass or more, excellent peelability and heat resistance can be obtained, and when it is 50 parts by mass or less, whitening of the release agent layer can be suppressed.

Various components of the copolymer and the like will be described below.

(A block)
The A block is a polymer block having a structural unit (a-1) represented by the following general formula (1). The structural unit (a-1) may have only one type or two or more types.

[In the formula (1), R ¹¹ represents an alkyl group having 12 to 28 carbon atoms. R ¹² represents a hydrogen atom or a methyl group. ]

An alkyl group is introduced into the A block by the structural unit (a-1) represented by the general formula (1). Therefore, the copolymer is a (meth) acrylic polymer having an alkyl group. When the carbon number of the alkyl group becomes too small, it is generally difficult for the (meth) acrylic polymer having an alkyl group to exhibit releasability (release property) due to the (meth) acrylic polymer, and residual adhesion is achieved. The force tends to decrease. Further, if the number of carbon atoms of the alkyl group becomes too large, the crystallinity becomes high, so that the peeling force becomes too high and the peeling performance deteriorates. ^{Therefore, by setting the carbon number of R 11} to 12 to 28 in the structural unit (a-1), the peeling performance becomes excellent. The carbon number of R ¹¹ is preferably 14 or more, more preferably 16 or more, preferably 26 or less, and more preferably 22 or less.

Examples ^{of the alkyl group of R 11} include a linear alkyl group, a branched chain alkyl group, a cyclic alkyl group and the like, and a linear alkyl group and / or a branched chain alkyl group are preferable.
Examples of the linear alkyl group include n-dodecyl group, n-tridecylic group, n-tetradecyl group, n-pentadecylic group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group (n-stearyl group), and the like. n-nonadecylic group, n-icosyl group, n-heicosyl group, n-dodecyl group, n-tridecylic group, n-tetracosyl group, n-heptacosyl group, n-hexacosyl group, n-heptacosyl group, n-octacosyl group Can be mentioned.
The branched chain alkyl group includes an isododecyl group, an isotridecyl group, an isotetradecyl group, an isopentadecyl group, an isohexadecyl group, an isooctadecyl group, an isononadecyl group, an isoicocil group, an isoheicosyl group, an isodocosyl group, an isotricosyl group and an isotetracosyl group. Examples thereof include a group, an isoheptacosyl group, an isohexacosyl group, an isoheptacosyl group, an isooctacosyl group and the like.
Examples of the cyclic alkyl group include a cyclic alkyl group having a monocyclic structure (for example, a cycloalkyl group), and specific examples thereof include an n-undecylcyclohexyl group and an n-dodecylcyclohexyl group.

Specific examples of the vinyl monomer forming the structural unit (a-1) represented by the general formula (1) include n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, and n-tetradecyl (meth) acrylate. , N-Pentadecyl (meth) acrylate, n-hexadecyl (meth) acrylate, n-heptadecyl (meth) acrylate, stearyl (meth) acrylate, n-nonadecyl (meth) acrylate, n-icosyl (meth) acrylate, n-heicosyl (Meta) acrylate, n-docosyl (meth) acrylate, n-tricosyl (meth) acrylate, n-tetracosyl (meth) acrylate, n-heptacosyl (meth) acrylate, n-hexacosyl (meth) acrylate, n-heptacosyl (meth) ) Acrylate, n-octacocil (meth) acrylate, isododecyl (meth) acrylate, isotridecyl (meth) acrylate, isotetradecyl (meth) acrylate, isopentadecyl (meth) acrylate, isohexadecyl (meth) acrylate, isoheptadecyl (meth). ) Acrylate, isostearyl (meth) acrylate, isononadecyl (meth) acrylate, isoicosyl (meth) acrylate, isoheicosyl (meth) acrylate, isodocosyl (meth) acrylate, isotricosyl (meth) acrylate, isotetracosyl (meth) acrylate, isoheptacosyl (meth) Examples thereof include acrylate, isohexacocil (meth) acrylate, isoheptacosyl (meth) acrylate, isooctacocil (meth) acrylate, n-undecylcyclohexyl (meth) acrylate, and n-dodecylcyclohexyl (meth) acrylate.

The A block may be only a structural unit (a-1) or may include other structural units. From the viewpoint of maintaining excellent peelability, the content of the structural unit (a-1) is preferably 40% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass in 100% by mass of the A block. As mentioned above, it is particularly preferably 95% by mass or more. Further, it is preferable that the A block does not substantially contain the structural unit (b-1) described later. That is, the content of the structural unit (b-1) is preferably 5% by mass or less, more preferably 2% by mass or less, still more preferably 1% by mass or less in 100% by mass of the A block.

The composition of the A block may be appropriately adjusted according to the pressure-sensitive adhesive layer or the adhesive layer to be bonded to the release sheet. When the adhesive layer bonded to the release sheet is relatively hard, as an embodiment of the A block ^{, a structural unit (a-1) having R 11} having 14 to 26 carbon atoms (preferably 16 to 22) is used. An embodiment containing 80% by mass or more (preferably 90% by mass or more, more preferably 95% by mass or more) in 100% by mass of the A block is preferable.

When the pressure-sensitive adhesive layer or the adhesive layer bonded to the release sheet is relatively soft, the aspect of the A block is a structural unit (preferably 12 to 15) in which the carbon number of ^{R 11 is 12 to 26 (preferably 12 to 15).} It is preferable that a-1) is contained in 100% by mass or more (preferably 45% by mass or more) in 100% by mass of the A block.
Further, in particular, the A block contains a structural unit (a-1-1) represented by the formula (1-1) and a structural unit (a-1-2) represented by the formula (1-2). Is preferable. In this case, the mass ratio ((a-1-1) / (a-1-2)) of the structural unit (a-1-1) and the structural unit (a-1-2) in the A block is 20 /. It is preferably 80 or more, more preferably 30/70 or more, further preferably 40/60 or more, preferably 80/20 or less, still more preferably 70/30 or less, still more preferably 60/40 or less. The total content of the structural unit (a-1-1) and the structural unit (a-1-2) in the A block is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably. It is 95% by mass or more.

[In the formula (1-1), R ¹³ represents an alkyl group having 12 to 15 carbon atoms. R ¹⁴ represents a hydrogen atom or a methyl group.
In formula (1-2), R ¹⁵ represents an alkyl group having 16 to 28 carbon atoms. R ¹⁶ represents a hydrogen atom or a methyl group. ]

Specific examples of the vinyl monomer capable of forming another structural unit of the A block include a (meth) acrylate having a linear alkyl group having 1 to 11 carbon atoms and a branched alkyl group having 3 to 11 carbon atoms (meth). ) Acrylate, (meth) acrylate having a cyclic alkyl group having 6 to 11 carbon atoms, (meth) acrylate having an aromatic group, (meth) acrylate having a polyalkylene glycol structural unit, (meth) acrylate having an alkoxy group, Examples thereof include (meth) acrylates having an oxygen-containing heterocyclic group, α-olefins, aromatic vinyl monomers, vinyl monomers containing a heterocycle, vinylamides, vinyl carboxylates, dienes and the like.

As the (meth) acrylate having a linear alkyl group having 1 to 11 carbon atoms, a (meth) acrylate having a linear alkyl group having 1 to 10 carbon atoms is preferable. A (meth) acrylate having a linear alkyl group having 1 to 5 carbon atoms is more preferable. Examples of the (meth) acrylate having a linear alkyl group having 1 to 11 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, and n-. Examples thereof include pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, and decyl (meth) acrylate.

As the (meth) acrylate having a branched-chain alkyl group having 3 to 11 carbon atoms, a (meth) acrylate having a branched-chain alkyl group having 3 to 10 carbon atoms is preferable. Examples of the (meth) acrylate having a branched chain alkyl group include isopropyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, isooctyl (meth) acrylate, and 2-. Examples thereof include ethylhexyl (meth) acrylate, isononyl (meth) acrylate, and isodecyl (meth) acrylate.

Examples of the (meth) acrylate having a cyclic alkyl group having 6 to 11 carbon atoms include cyclohexyl (meth) acrylate and methylcyclohexyl (meth) acrylate.

The (meth) acrylate having an aromatic group is preferably a (meth) acrylate having an aromatic group having 6 to 12 carbon atoms, and is preferably a (meth) acrylate having an aromatic group having 6 to 9 carbon atoms. It is more preferable to have. Examples of the aromatic group include an aryl group and the like, and may have a chain portion such as an alkylaryl group, an aralkyl group, an aryloxyalkyl group and the like. Specific examples of the (meth) acrylate having an aromatic group include benzyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate and the like.

Examples of the (meth) acrylate having a polyalkylene glycol structural unit include polyethylene glycol (polymerization degree = 2 to 10) methyl ether (meth) acrylate, polyethylene glycol (polymerization degree = 2 to 10) ethyl ether (meth) acrylate, and polyethylene. Polyethylene glycol (meth) acrylate having a polyethylene glycol structural unit such as glycol (polymerization degree = 2 to 10) propyl ether (meth) acrylate; polypropylene glycol (polymerization degree = 2 to 10) methyl ether (meth) acrylate, polypropylene glycol (polymerization degree). = 2 to 10) (meth) acrylate having a polypropylene glycol structural unit such as ethyl ether (meth) acrylate and polypropylene glycol (polymerization degree = 2 to 10) propyl ether (meth) acrylate can be mentioned.

Examples of the (meth) acrylate having an alkoxy group include methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate.

As the (meth) acrylate having an oxygen-containing heterocyclic group, a (meth) acrylate having a 4-membered ring to 6-membered ring oxygen-containing heterocyclic group is preferable. Specific examples of the (meth) acrylate having an oxygen-containing heterocyclic group include glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, (3-ethyloxetane-3-yl) methyl (meth) acrylate, and (2-). Methyl-2-ethyl-1,3-dioxolan-4-yl) methyl (meth) acrylate, cyclic trimethylolpropaneformal (meth) acrylate, 2-[(2-tetrahydropyranyl) oxy] ethyl (meth) acrylate, Examples thereof include 1,3-dioxane- (meth) acrylate.

Examples of the α-olefin include 1-hexene, 1-octene, 1-decene and the like.
Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methoxystyrene, 2-hydroxymethylstyrene, 1-vinylnaphthalene and the like.
Examples of the vinyl monomer containing the heterocycle include 2-vinylthiophene, N-methyl-2-vinylpyrrole, 1-vinyl-2-pyrrolidone, 2-vinylpyridine, 4-vinylpyridine, N-phenylmaleimide, and N-. Examples thereof include benzylmaleimide and N-cyclohexylmaleimide.
Examples of the vinyl amide include N-vinylformamide, N-vinylacetamide, N-vinyl-ε-caprolactam and the like.
Examples of the vinyl carboxylate include vinyl acetate, vinyl pivalate, vinyl benzoate and the like.
Examples of the diene include butadiene, isoprene, 4-methyl-1,4-hexadiene, 7-methyl-1,6-octadien and the like.

It is preferable that the A block does not have a reactive functional group (hydroxy group, amino group, thiol group, carboxy group, sulfonic acid group, phosphoric acid group, phosphonic acid group, phosphinic acid group). When the release agent layer is formed by using the release agent composition, it is considered that the block copolymer segregates on the surface of the release agent layer. At this time, in the block copolymer, the B block is located on the aminoalkyd resin side and the A block is located on the surface side of the release agent layer. Therefore, if the A block does not have a reactive functional group, the release agent There will be no reactive functional groups on the surface of the layer. Therefore, even when the release agent layer is exposed to a high temperature (for example, 100 ° C. or higher) with the pressure-sensitive adhesive or the adhesive in contact with the adhesive layer, the increase in the release force is suppressed.

When two or more kinds of structural units are contained in the A block, the various structural units contained in the A block may be contained in the A block in any mode such as random copolymerization and block copolymerization. , It is preferable that it is contained in the form of random copolymerization from the viewpoint of uniformity. For example, the A block may be formed by a copolymer of a structural unit consisting of a1 block and a structural unit consisting of a2 block.

(B block)
The B block is a polymer block having a structural unit (b-1) derived from a vinyl monomer having a reactive functional group. The structural unit (b-1) may have only one type or two or more types.

The reactive functional group of the structural unit (b-1) is a functional group that can react with the functional group of the aminoalkyd resin and / or the melamine-based cross-linking agent described later. Examples of the vinyl monomer having a reactive functional group forming the structural unit (b-1) include a (meth) acrylic monomer having a reactive functional group and a vinyl monomer having a reactive functional group other than the (meth) acrylic monomer. Can be mentioned.

Examples of the reactive functional group of the structural unit (b-1) include a hydroxy group, an amino group, a carboxy group, a thiol group and the like. Such a reactive functional group may be contained alone or in combination of two or more. Among these reactive functional groups, a hydroxy group or a carboxy group is preferable, and a hydroxy group is more preferable from the viewpoint of reactivity with an aminoalkyd resin and / or a melamine-based cross-linking agent.

The vinyl monomer forming the structural unit (b-1) includes a (meth) acrylic monomer having a hydroxy group, a (meth) acrylic monomer having an amino group, a (meth) acrylic monomer having a carboxy group, and a thiol group. (Meta) acrylic monomer, vinyl monomer other than (meth) acrylic monomer having a hydroxy group, vinyl monomer other than (meth) acrylic monomer having an amino group, vinyl monomer other than (meth) acrylic monomer having a carboxy group, thiol group Examples thereof include vinyl monomers other than the (meth) acrylic monomers having the above.

Examples of the (meth) acrylic monomer having a hydroxy group include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-. Hydroxyalkyl (meth) acrylates such as hydroxyhexyl (meth) acrylates, 8-hydroxyoctyl (meth) acrylates, 10-hydroxydecyl (meth) acrylates, 12-hydroxylauryl (meth) acrylates; caprolactone of hydroxyalkyl (meth) acrylates. Additives and the like can be mentioned. Among these, hydroxyalkyl (meth) acrylates are preferable, and (meth) acrylates having a hydroxyalkyl group having 1 to 5 carbon atoms are more preferable.

Examples of the (meth) acrylic monomer having an amino group include aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, and aminobutyl (meth) acrylate.

Examples of the (meth) acrylic monomer having a carboxy group include maleic anhydride and succinic anhydride in a (meth) acrylate having a hydroxy group such as 2- (meth) acryloyloxyethyl succinate and 2- (meth) acryloyloxyethyl maleate. Monomer reacted with acid anhydride such as acid, (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, 1,4-di (meth) acryloyloxyethyl pyromellitic acid, 4- ( Examples thereof include (meth) acryloxyethyl trimellitic acid and 2- (meth) acryloyloxybenzoic acid.

Examples of the vinyl monomer other than the (meth) acrylic monomer having a hydroxy group include allyl alcohol and the like.
Examples of the vinyl monomer other than the (meth) acrylic monomer having an amino group include allylamine and the like.
Examples of the vinyl monomer other than the (meth) acrylic monomer having a carboxy group include crotonic acid, maleic acid, itaconic acid, citraconic acid, and cinnamon acid.

The B block may be only a structural unit (b-1) or may include other structural units. From the viewpoint of maintaining excellent peelability, the content of the structural unit (b-1) is preferably 30% by mass or more, more preferably 40% by mass or more, still more preferably 50% by mass in 100% by mass of the B block. As mentioned above, it is more preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 95% by mass or more. Further, it is preferable that the B block does not substantially contain the structural unit (a-1). That is, the content of the structural unit (a-1) is 50% by mass or less, preferably 5% by mass or less, more preferably 2% by mass or less, and further preferably 1% by mass or less in 100% by mass of the B block. preferable.

As a specific example of the vinyl monomer capable of forming another structural unit of the B block, the same one as exemplified as a specific example of the vinyl monomer capable of forming another structural unit of the A block can be mentioned.

When two or more kinds of structural units are contained in the B block, the various structural units contained in the B block may be contained in the B block in any mode such as random copolymerization and block copolymerization. , It is preferable that it is contained in the form of random copolymerization from the viewpoint of uniformity. For example, the B block may be formed by a copolymer of a structural unit composed of b1 blocks and a structural unit composed of b2 blocks.

(1-2-3. Method for producing copolymer)
As a method for producing the copolymer, a method in which an A block is first produced by a polymerization reaction of vinyl monomers and a B block monomer is polymerized in an A block; a B block is first produced and an A block is formed in a B block. A method of polymerizing the monomers of the above; a method of coupling the A block and the B block after separately producing the A block and the B block can be mentioned.

The polymerization method is not particularly limited, but living radical polymerization is preferable. That is, the copolymer preferably polymerized by living radical polymerization. The living radical polymerization method maintains the convenience and versatility of the conventional radical polymerization method, but is less likely to cause a termination reaction or chain transfer, and grows without being hindered by a side reaction that deactivates the growth end. It is preferable in that precise control of the above and easy production of a polymer having a uniform composition.

The living radical polymerization method includes a method using a transition metal catalyst (ATRP method); a method using a sulfur-based reversible chain transfer agent (RAFT method); and an organotellurium compound, depending on the method for stabilizing the polymerization growth end. There are methods such as the method used (TERP method). Among these, it is preferable to use the TERP method from the viewpoints of the variety of monomers that can be used, the control of the molecular weight in the polymer region, the uniform composition, or the coloring.

The TERP method is a method of polymerizing a radically polymerizable compound (vinyl monomer) using an organotellurium compound as a chain transfer agent. For example, International Publication No. 2004/14848, International Publication No. 2004/14962, International Publication No. The method described in 2004/072126 and 2004/096870.

Specific polymerization methods of the TERP method include the following (a) to (d).
(A) A method for polymerizing a vinyl monomer using an organic tellurium compound represented by the general formula (6).
(B) A method for polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by the general formula (6) and an azo-based polymerization initiator.
(C) A method for polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by the general formula (6) and an organic diterlide compound represented by the general formula (7).
(D) A method for polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by the general formula (6), an azo-based polymerization initiator and an organic diterlide compound represented by the general formula (7).

[In the formula (6), R ⁶¹ represents an alkyl group having 1 to 8 carbon atoms, an aryl group or an aromatic heterocyclic group. R ⁶² and R ⁶³ each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R ⁶⁴ represents an alkyl group having 1 to 8 carbon atoms, an aryl group, a substituted aryl group, an aromatic heterocyclic group, an alkoxy group, an acyl group, an amide group, an oxycarbonyl group, a cyano group, an allyl group or a propargyl group.
In formula (7), R ⁶¹ represents an alkyl group, an aryl group or an aromatic heterocyclic group having 1 to 8 carbon atoms. ]

The organic tellurium compound represented by the general formula (6) is specifically ethyl-2-methyl-2-n-butylteranyl-propionate, ethyl-2-n-butylteranyl-propionate, (2-hydroxyethyl) -2. Examples thereof include the organic tellurium compounds described in International Publication No. 2004/14848, International Publication No. 2004/14962, International Publication No. 2004/072126, and International Publication No. 2004/096870, such as methyl-methylteranyl-propionate. .. Specific examples of the organic diterlide compound represented by the general formula (7) include dimethyl diterlide and dibutyl diterlide. The azo-based polymerization initiator can be used without particular limitation as long as it is an azo-based polymerization initiator used in ordinary radical polymerization. For example, 2,2'-azobis (isobutyronitrile) (AIBN), 2 , 2'-azobis (2,4-dimethylvaleronitrile) (ADVN), 1,1'-azobis (1-cyclohexanecarbonitrile) (ACHN), 2,2'-azobis (4-methoxy-2,4- Dimethylvaleronitrile) (V-70) and the like can be mentioned.

The polymerization step is a container substituted with an inert gas, and the vinyl monomer and the organic tellurium compound of the general formula (6) are further azo for the purpose of promoting a reaction depending on the type of the vinyl monomer, controlling the molecular weight and the molecular weight distribution, and the like. The system polymerization initiator and / or the organic diterlide compound of the general formula (7) are mixed. At this time, examples of the inert gas include nitrogen, argon, and helium. Argon and nitrogen are preferable. The amount of the vinyl monomer used in the above (a), (b), (c) and (d) may be appropriately adjusted according to the physical characteristics of the target copolymer.

The polymerization reaction can be carried out without a solvent, but the mixture may be stirred by using an aprotic solvent or a protic solvent generally used in radical polymerization. Examples of the aprotic solvent that can be used include anisole, benzene, toluene, propylene glycol monomethyl ether acetate, ethyl acetate, tetrahydrofuran (THF) and the like. Examples of the protonic solvent include water, methanol, 1-methoxy-2-propanol and the like. The solvent may be used alone or in combination of two or more. The amount of the solvent used may be appropriately adjusted, and for example, 0.01 ml to 50 ml is preferable with respect to 1 g of the vinyl monomer. The reaction temperature and reaction time may be appropriately adjusted depending on the molecular weight or molecular weight distribution of the obtained copolymer, but usually, the mixture is stirred at 0 ° C to 150 ° C for 1 minute to 100 hours. After the completion of the polymerization reaction, the solvent used, the residual vinyl monomer, and the like can be removed from the obtained reaction mixture by ordinary separation and purification means to separate the desired copolymer.

The growth end of the copolymer obtained by the polymerization reaction is in the form of —TeR ⁶¹ (in the formula, R ⁶¹ is the same as above) derived from the tellurium compound, and is inactivated by an operation in air after the completion of the polymerization reaction. However, tellurium atoms may remain. Since the copolymer in which the tellurium atom remains at the terminal is colored or has poor thermal stability, it is preferable to remove the tellurium atom. Examples of the method for removing the tellurium atom include a radical reduction method; a method of adsorbing with activated carbon or the like; a method of adsorbing a metal with an ion exchange resin or the like, and these methods can also be used in combination. The other end of the copolymer obtained by the polymerization reaction (the end opposite to the growth end) is -CR ⁶² R ⁶³ R ⁶⁴ derived from the tellurium compound (in the formula, R ⁶² , R ⁶³ and R ⁶⁴ are of the formula. (6) It is the same ^{as R 62} , R ⁶³ and R ^{64 in).}

(Acid catalyst)
The aminoalkyd resin composition may contain an acidic catalyst, if necessary. Examples of the acidic catalyst include organic acids such as acetic acid and oxalic acid; mineral acids such as hydrochloric acid, sulfuric acid and phosphoric acid; organic acids such as diethylsulfuric acid, paratoluenesulfonic acid, paraphenolsulfonic acid, benzenesulfonic acid and methanesulfonic acid. Sulphonic acid; organic phosphonic acids such as 1-hydroxyethylidene-1,1'-diphosphonic acid and 2-phosphonobutane-1,2,4-tricarboxylic acid can be used. Among these, p-toluenesulfonic acid is preferable. The acidic catalyst may be used alone or in combination of two or more.

When the acidic catalyst is blended, the content of the acidic catalyst is preferably 0.1 part by mass to 15 parts by mass with respect to 100 parts by mass in total of the solid content (components other than the solvent) of the aminoalkyd resin composition. It is more preferably 3 parts by mass to 12 parts by mass, and further preferably 5 parts by mass to 10 parts by mass. When the content of the acidic catalyst is within the above range, the strength of the release agent layer is further improved.

(Other additives)
In addition to the above-mentioned components, other additives may be blended and used in the aminoalkyd resin composition, if necessary. Examples of other additives include antioxidants, chlorine absorbers, ultraviolet absorbers, plasticizers, flame retardants, antistatic agents, colorants, antiblocking agents and the like. These are appropriately selected and blended according to the intended use and purpose of the release sheet. Other additives may be used alone or in combination of two or more.

Examples of the antioxidant include phenol-based acid antioxidants, hindered amine-based antioxidants, phosphite-based antioxidants, lactone-based antioxidants, tocopherol-based antioxidants, and the like. Specifically, 2,6-di-t-butyl-p-cresol, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,3,5- Examples thereof include trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxy) benzene and tris (2,4-di-t-butylphenyl) phosphite.

Examples of the chlorine absorber include metal soaps such as calcium stearate.
Examples of the ultraviolet absorber include benzotriazole, benzophenone, hydroxybenzoate and the like.
Examples of the plasticizer include citric acid ester, dibutyl phthalate, polyethylene glycols, propylene glycols, glycerin and the like.
Examples of the flame retardant include phosphazene-based compounds, phosphoric acid esters, condensed phosphoric acid esters, inorganic phosphorus-based, halogen-based, silicone-based flame retardants, metal oxide-based flame retardants, metal hydroxide-based flame retardants, and organic metals. Examples thereof include salt-based flame retardants, nitrogen-based flame retardants, and boron compound-based flame retardants.
Examples of the antistatic agent include glycerin monoester (glycerin monostearate and the like), ethoxylated secondary amines and the like.
Examples of the colorant include various colored dyes, colored pigments, and fluorescent dyes.

The anti-blocking agent is added to prevent blocking and is not particularly limited as long as it does not exhibit its effect as a nucleating agent. Examples of the anti-blocking agent include inorganic particles and organic particles. Examples of the inorganic particles include particles such as silica, alumina, (synthetic) zeolite, calcium carbonate, kaolin, talc, mica, zinc oxide, magnesium oxide, quartz, magnesium carbonate, parium sulfate, and titanium dioxide. Examples of the organic particles include polystyrene resin, polyacrylic resin, polymethylmethacrylate (PMMA) resin, crosslinked polyethylene resin, polyester resin, polyamide resin, polycarbonate resin, polyether resin, polyether sulfone resin, and polyetherimide resin. , Polyphenylene sulfide resin, polyether ether ketone resin, polyamideimide resin, benzoguanamine resin, furan resin, epoxy resin, phenol resin, unsaturated polyester resin, vinyl ester resin, diallyl phthalate resin, polyimide resin, fatty acid amide resin and fatty acid glycerin ester. Examples include particles such as compounds. Among these, PMMA resin particles and silica particles are more preferable because they are excellent in blocking resistance and slipperiness. The anti-blocking agent preferably has a particle size of 0.1 μm to 10 μm.

It is preferable that the aminoalkyd resin composition does not substantially contain a silicone compound. Substantially free of silicone compounds means that the content of the silicone compounds in the solid content (components other than the solvent) of the aminoalkyd resin composition is 10% by mass or less, more preferably 5% by mass. % Or less, most preferably 0% by mass.

(Manufacturing method of aminoalkyd resin composition)
The aminoalkyd resin composition can be produced by mixing the constituent components of the aminoalkyd resin with a block copolymer, an acidic catalyst used if necessary, and other additives. The aminoalkyd resin composition contains a solvent derived from the production of the block copolymer, or is further diluted with a suitable solvent so as to have a viscosity suitable for forming a release agent layer. It may be a diluted solution.

As the solvent used in the aminoalkido resin composition, ethanol, isopropyl alcohol (IPA), n-butyl alcohol (NBA), ethylene glycol monomethyl ether (EGM), ethylene glycol monoisopropyl ether (IPG), propylene glycol monomethyl ether ( Alcohol-based solvents such as PGM) and diethylene glycol monobutyl ether; ketone solvents such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclohexanone and acetone; aromatic hydrocarbon solvents such as toluene and xylene; ethyl acetate (EtAc) , Ester-based solvents such as propyl acetate, isopropyl acetate, butyl acetate (BuAc); organic solvents such as amide-based solvents such as N-methylpyrrolidone, acetamide and dimethylformamide. These may be used alone as a solvent, or may be used in combination of two or more.

<Manufacturing of mold release sheet>
The release sheet protects the adhesive surface and the adhesive surface during storage and manufacturing of electronic parts by attaching the release agent layer to the adhesive or adhesive, and is a so-called release sheet, process sheet, or the like. It is a general term for sheets that have a "peeling function".

(Base sheet)
The base material sheet is not particularly limited, and a commonly used base material can be used. Examples of the base material sheet include paper (high quality paper, dust-free paper, glassin paper, clay coated paper, resin coated paper, laminated paper (polyethylene laminated paper, polypropylene laminated paper, etc.), non-woven fabric, metal foil, polymer sheet, glass sheet). And so on.

Examples of the polymer material constituting the polymer sheet include polyethylene terephthalate resin, polyethylene naphthalate resin, polycarbonate resin, poly (meth) acrylate resin, polystyrene resin, polyamide resin, polyimide resin, polyacrylonitrile resin, polypropylene resin, and polyethylene resin. , Polycycloolefin resin, cycloolefin copolymer resin, polyphenylene sulfide resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, polyether ether ketone resin and the like. Among these, from the viewpoints of heat resistance, strength, adhesion to the mold release agent, handleability, etc., the polymer materials include polyethylene terephthalate resin, polyethylene naphthalate resin, polyimide resin, polycarbonate resin, and poly (meth) acrylate. Resins, polyamide resins, polycycloolefin resins, cycloolefin copolymer resins, and polyether ether ketone resins are preferred. The polymer sheet may be composed of a single layer composed of a layer containing one or more of the polymer materials, or a layer containing one or more of the polymer materials and the layer containing one or more of the polymer materials. It may be composed of two or more layers, such as a layer containing one kind or two or more kinds of polymer materials different from the layer.

The thickness of the base material sheet is not particularly limited, but is preferably 2 μm to 500 μm, more preferably 2 μm to 200 μm, from the viewpoint of excellent handleability and the like.

The base material sheet may be surface-treated in order to improve the adhesion with the release agent layer. Examples of the surface treatment include corona treatment, plasma treatment, hot air treatment, ozone treatment, ultraviolet treatment and the like. Further, an easy-adhesion layer may be provided on the surface of the base material sheet. Further, various functional layers such as a gas barrier property improving layer, an antistatic layer, and an oligomer block layer may be provided on the surface of the base material sheet.

(Release agent layer)
The release agent layer is formed on at least one surface of the base sheet. The release agent layer can be formed by applying the aminoalkyd resin composition and drying, curing or the like as necessary. When the aminoalkyd resin composition is cured, the constituent components of the aminoalkyd resin and the block copolymer are crosslinked by the N-methylol group and / or the N-alkoxymethylol group contained in the composition. To form an interpenetrating polymer network. Therefore, the release agent layer formed from the aminoalkyd resin composition is excellent in strength.

The method of applying the aminoalkyd resin composition is not particularly limited, and the coating method (reverse gravure coating method, direct gravure coating method, die coating method, bar coating method, wire bar coating method, roll coating method, spin coating method, dip) is not particularly limited. A coating method, a spray coating method, a knife coating method, a kiss coating method, etc.), an inkjet method, and a printing method (offset printing, screen printing, flexographic printing, etc.) can be adopted.

From the viewpoint of the curability of the coating film, the aminoalkyl resin composition is preferably dried and cured at 100 ° C. to 170 ° C. for 10 seconds to 60 seconds, and at 140 ° C. to 160 ° C. for 20 seconds to 40 seconds. Is more preferable.

The thickness of the release agent layer is preferably 0.03 μm or more, more preferably 0.05 μm or more, still more preferably 0.07 μm or more, from the viewpoint of mold release performance, workability, and the like. Further, from the viewpoint of curability, it is preferably 0.5 μm or less, more preferably 0.3 μm or less, still more preferably 0.2 μm or less.

It is preferable that the release agent layer of the release sheet does not substantially contain a silicone compound in order to reduce adverse effects on electrical parts and the like. The term "substantially free of the silicone compound" means that the amount of the silicone compound is preferably 500 μg / g or less, more preferably 100 μg / g or less.

In the release sheet, the surface of the release agent layer (the surface in contact with the adhesive and the adhesive) may be matted. When the adhesive is applied to the release sheet whose surface of the release agent layer is matted, the adhesive surface is matted. Therefore, for example, when the release sheet is used as the adhesive sheet for the interphase insulating film of the printed wiring board, the adhesive surface of the adhesive sheet is matted, and the workability in the manufacturing process of the printed wiring board can be improved.

When the surface of the release agent layer is matted, the arithmetic average roughness Ra (JIS B0601: 2013) of the surface of the release agent layer is preferably 0.3 μm to 1.0 μm, more preferably 0.5 μm to 0. It is 0.8 μm. The maximum height Rz (JIS B0601: 2013) of the surface of the release agent layer is preferably 4 μm to 11 μm, more preferably 6 μm to 9 μm. If the arithmetic average roughness and maximum height of the surface of the release agent layer are within the above ranges, the surface of the adhesive or adhesive to be attached can be sufficiently roughened, and positioning when the printed wiring boards are bonded to each other can be sufficiently roughened. The ease of use is improved, and air bubbles between the adhesive or adhesive and the printed wiring board are easily released.

As a method of matting the release agent layer, there is a method of applying a matte treatment to the base material sheet on which the release agent layer is formed. By applying the matte treatment to the base material sheet, the surface of the release agent layer formed on the base material sheet is also matted. As a method of matting, a method of sandblasting the surface of the base sheet, a method of forming a mat layer by coating on the base sheet, a method of molding from a resin kneaded with inorganic or organic particles, and a resin. Examples thereof include a method of molding with a mat roll while molding. Among these, a method of forming a matte layer by coating is preferable from the viewpoint of ease of controlling the surface roughness.

As a method for forming the matte layer by coating, the same method as that used for forming the release agent layer can be used. For example, a coating agent composition containing a binder resin and particles is formed into a base sheet. A method of forming a matte layer by phase-separating two or more kinds of materials, and the like can be mentioned.

The release sheet can be used to protect the adhesive surface or the adhesive surface of the adhesive tape or the sheet-like adhesive. Further, even when the release sheet is exposed to a high temperature in a state of being attached to an adhesive or an adhesive, an increase in peeling force is suppressed. Therefore, the release sheet can be suitably used for applications exposed to 100 ° C. or higher (particularly 150 ° C. or higher) in a state of being attached to an adhesive or an adhesive. Specifically, it is a release sheet used in the process of forming a sheet-like adhesive or a sheet-like adhesive, and is a release sheet exposed to 100 ° C. or higher when forming an adhesive layer or an adhesive layer; a sheet-like release sheet. Examples of the release sheet used for heat-pressing and transferring an adhesive to an adherend include a release sheet exposed to 100 ° C. or higher (particularly 150 ° C. or higher) during hot pressing. The pressure-sensitive adhesive or adhesive to which the release sheet is attached is not limited, and examples thereof include pressure-sensitive adhesives and adhesives having a hydroxy group, a carboxy group, and an epoxy group.

Hereinafter, the present invention will be described in more detail based on specific examples. The present invention is not limited to the following examples, and can be appropriately modified and implemented without changing the gist thereof. The polymerization rate, weight average molecular weight (Mw), molecular weight distribution (PDI) of the copolymer, and the peeling force, heat resistance, residual adhesive rate, peeling force, strength, and appearance of the peeling layer are as follows. Evaluated according to the method.

The meanings of the abbreviations are as follows.
BTEE: Ethyl-2-methyl-2-n-butylteranyl-propionate AIBN: 2,2'-azobis (isobutyronitrile)
SA: Stearyl acrylate SMA: Stearyl methacrylate LA: Lauryl acrylate 4-HBA: 4-Hydroxybutyl acrylate 2-HEMA: 2-Hydroxyethyl methacrylate AcOEt: Ethyl acetate MeOH: Methanol MEK: Methylethyl ketone

[Evaluation method]
(Polymerization rate)
¹ H-NMR was measured (solvent: CDCl ₃ , internal standard: trimethylsilane) using a nuclear magnetic resonance (NMR) measuring device (manufactured by Bruker Biospin, model: AVANCE500 (frequency 500 MHz)). With respect to the obtained NMR spectrum, the integral ratio of the peaks of the vinyl group derived from the monomer and the ester side chain derived from the polymer was obtained, and the polymerization rate of the monomer was calculated. With respect to the NMR spectrum of the final product, the integral ratio of the peaks of the ester side chains of each component was obtained, and the content of each component was calculated.

(Weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (PDI))
It was determined by gel permeation chromatography (GPC) using a high performance liquid chromatograph (manufactured by Tosoh, model HLC-8320GPC). Two TSKgel Super Multipore HZ-H (manufactured by Tosoh Corporation) were used as columns, a tetrahydrofuran solution was used for the mobile phase, and a differential refractometer was used for the detector. The measurement conditions were a column temperature of 40 ° C., a sample concentration of 10 mg / mL, a sample injection amount of 10 μm, and a flow rate of 0.2 mL / min. Calibration curve using polystyrene (molecular weight 109,000, 775,000, 427,000, 289,000, 190,000, 96,400, 37,900, 10,200, 2,630, 440) as a standard material (Calibration curve) was prepared, and the weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured. The molecular weight distribution (PDI = Mw / Mn) was calculated from this measured value.

(Thickness of mold release agent layer)
The thickness of the release agent layer was measured by a spectroscopic interference method using a film thickness measuring system (“Filmetics F20” manufactured by Filmometrics Co., Ltd.).

(Normal peeling force)
The release surface (release agent layer) of the release sheet is the adhesive layer surface of the polyester base material adhesive tape "NO.31B" (manufactured by Nitto Denko Co., Ltd., tape width 25 mm, adhesive layer thickness 8 μm, total thickness 50 μm). The bonded body was placed on a glass plate and reciprocated once with a 5 kg roller to be crimped. Then, it was aged at room temperature (23 ° C.) for 20 hours to prepare a sample for measuring the normal peeling force.
Using a precision universal testing machine "Autograph AGS-1kNX, 50N load cell" manufactured by Shimadzu Corporation, a sample for measuring normal peeling force was used in an environment of 23 ° C and 50%, with a peeling speed of 0.3 m / min and a peeling angle of 90 °. The peeling force was measured.

(Heat-resistant)
The release sheet was placed on a glass plate with the release surface facing up, and heated at 150 ° C. for 1 hour using a constant temperature bath. Then, the release force of the release sheet after the heat treatment was measured in the same manner as the normal release force, and the heat resistance of the release sheet was evaluated.
If this measured value is large, after the heat pressing and reflow process of the adhesive sheet with the release sheet, the peeling force becomes large and the workability deteriorates, or the release sheet or the sheet-like adhesive is destroyed. means.

(Peeling force after heating)
The release surface of the release sheet is attached to the adhesive layer surface of the polyester base material adhesive tape "NO.31B" (manufactured by Nitto Denko, tape width 25 mm, adhesive layer thickness 8 μm, total thickness 50 μm), and the bonded body is bonded. It was placed on a glass plate and reciprocated once with a 5 kg roller for crimping. After that, the bonded body was sandwiched between two glass plates, a load of 760 g was applied, and the mixture was heated at 100 ° C. for 20 hours using a constant temperature bath to prepare a sample for measuring the peeling force after heating.
Using a precision universal testing machine "Autograph AGS-1kNX, 50N load cell" manufactured by Shimadzu Corporation, a sample for measuring the peeling force after heating was used in an environment of 23 ° C and 50%, with a peeling speed of 0.3 m / min and a peeling angle of 90 °. The peeling force was measured at.

(Residual adhesion rate)
The polyester base material adhesive tape "NO.31B" (manufactured by Nitto Denko Co., Ltd., tape width 25 mm, adhesive layer thickness 8 μm, total thickness 50 μm) after being used for the measurement of the post-heating peeling force test is used as an aluminum sheet “A1N30”. -O material "(manufactured by Tokai Aluminum Co., Ltd., sheet width 50 mm, thickness 0.1 mm) was applied, and the mixture was crimped by reciprocating once with a 5 kg roller and then aged at room temperature (23 ° C.) for 20 hours. The adhesive strength was measured at a peeling speed of 0.3 m / min and a peeling angle of 180 ° in an environment of 23 ° C. and 50% using a precision universal testing machine “Autograph AGS-1kNX, 50N load cell” manufactured by Shimadzu Corporation.
Similarly, an unused polyester base material adhesive tape (not attached to the release sheet) was attached onto the aluminum sheet, and the initial adhesive force was measured at a peeling angle of 180 °.
From these measured values, the residual adhesion ratio was determined.
Residual adhesion rate (%) = (adhesive strength / initial adhesive strength) x 100

(Peeling force against the adhesive layer)
Using a baker-type applicator on the release surface of the release sheet, a thermosetting epoxy adhesive "FM-1502" (epoxy resin composition manufactured by Totoku Paint Co., Ltd.) so that the film thickness after drying is 50 μm. 20% by mass, 60% by mass of silicon dioxide, a solvent (methyl ethyl ketone), and a solid content concentration of 80% by mass) were applied. After applying the adhesive, it was dried at 130 ° C. for 5 minutes using a constant temperature dryer to prepare a transfer sheet having an adhesive layer on the release sheet. The prepared transfer sheet was stored at room temperature (23 ° C.) for 2 weeks.
The transfer sheet is cut out to 25 x 150 mm, and the adhesive layer surface faces the roughened surface of the electrolytic copper foil "CF-T4X-SV-12" (manufactured by Fukuda Metal Foil Powder Industry Co., Ltd., thickness 12 μm) of 30 × 160 mm. The test pieces were laminated in this manner and pressed at 100 ° C. and 2 MPa for 5 minutes using a high-temperature heat press machine “H400-15” manufactured by AS ONE Co., Ltd. to prepare test pieces.
For the test piece, the peeling force between the adhesive layer and the release sheet was measured by using a precision universal testing machine "Autograph AGS-1kNX, 50N load cell" manufactured by Shimadzu Corporation in an environment of 23 ° C. and 50%, and the peeling speed was 0. The measurement was performed at 3 m / min and a release angle of 180 °. The measurement was carried out on a test piece that was allowed to stand at room temperature (23 ° C.) for 30 minutes after preparation and a test piece that was stored at room temperature (23 ° C.) for 2 weeks after preparation.

(Strength)
The release surface (release agent layer) of the release sheet was rubbed strongly with a finger 5 times, and the rubbed portion was visually observed.
The evaluation criteria are as follows.
◯: No smear (the rubbed part becomes cloudy) or love-off (the rubbed part falls off).
X: Sumi or love-off has occurred.

(exterior)
The release sheet immediately after forming the release agent layer was visually observed. Compared to the base sheet before forming the release agent layer, the one that looks white and turbid is "x", the one that looks slightly white and turbid but has no practical problem is "△", and the one that does not change is "". ○ ”.

<Synthesis of copolymer>
Copolymer No. 1
SA (570.0 g), AIBN (0.433 g) and AcOEt (380.0 g) are charged in a flask equipped with an argon gas introduction tube and a stirrer, and after argon substitution, BTEE (3.00 g) is added and 60. The reaction was carried out at ° C. for 24 hours to polymerize the A block. The polymerization rate was 96%.

A mixed solution of 4-HBA (30.0 g), AIBN (0.098 g), and AcOEt (20.0 g) previously substituted with argon was added to the reaction solution, and the mixture was reacted at 60 ° C. for 16 hours to polymerize the B block. The polymerization rate was 85%.

After the reaction was completed, it was poured into the stirring MeOH. The precipitated polymer was suction-filtered and dried to obtain a copolymer No. I got 1. The obtained copolymer No. In 1, Mw is 50,770, PDI is 1.42, and the content of each component in the polymer is 91.1 mol% (95.9% by mass) for SA and 8.9 mol% (4.) for 4-HBA. 2% by mass). The obtained copolymer No. Toluene was added to 1 to give a solid content concentration of 52.0% by mass.

Copolymer No. 2
SA (19.6 g), 4-HBA (0.4 g), AIBN (13.1 mg), AcOEt (13.4 g) were charged in a test tube equipped with a stirrer, and after argon substitution, BTEE (120.0 mg) was charged. ) Was added, and the mixture was reacted at 60 ° C. for 24 hours. The polymerization rate was 89%.

After the reaction was completed, it was poured into the stirring MeOH. The precipitated polymer was suction-filtered and dried to obtain a copolymer No. I got 2. The obtained copolymer No. In 2, Mw is 46,510, PDI is 1.46, and the content of each component in the polymer is 95.2 mol% (97.8% by mass) for SA and 4.8 mol% (2.) for 4-HBA. 2% by mass). The obtained copolymer No. Toluene was added to 2 to give a solid content concentration of 37.5% by mass.

Copolymer No. 3
SA (9.5 g), LA (9.5 g), AIBN (13.1 mg), AcOEt (12.7 g) were charged in a test tube equipped with a stirrer, and after argon substitution, BTEE (120.0 mg) was added. In addition, the reaction was carried out at 60 ° C. for 20 hours to polymerize the A block. The polymerization rate was 96%.

A mixed solution of 4-HBA (1.0 g), AIBN (6.6 mg) and AcOEt (0.7 g) previously substituted with argon was added to the reaction solution, and the mixture was reacted at 60 ° C. for 22 hours to polymerize the B block. The polymerization rate was 81%.

After the reaction was completed, it was poured into the stirring MeOH. The precipitated polymer was suction-filtered and dried to obtain a copolymer No. I got 3. The obtained copolymer No. In 3, Mw is 48,782, PDI is 1.44, and the content of each component in the polymer is 39.3 mol% (47.9% by mass) for SA and 53.1 mol% (47.9% by mass) for LA. %), 4-HBA was 7.6 mol% (4.1% by mass). The obtained copolymer No. Toluene was added to 3 to give a solid content concentration of 31.2% by mass.

Copolymer No. 4
SMA (19.0 g), AIBN (13.1 mg) and AcOEt (12.7 g) are charged in a test tube equipped with a stirrer, and after argon substitution, BTEE (120.0 mg) and DBDT (73.9 mg) are added. In addition, the reaction was carried out at 60 ° C. for 21 hours to polymerize the A block. The polymerization rate was 96%.
A mixed solution of 2-HEMA (1.0 g), AIBN (6.6 mg), and AcOEt (0.7 g) previously substituted with argon was added to the reaction solution, and the mixture was reacted at 60 ° C. for 22 hours to polymerize the B block. The polymerization rate was 81%.
After completion of the reaction, the mixture was poured into stirring MeOH. The precipitated polymer was suction-filtered and dried to obtain a copolymer No. I got 4. The obtained copolymer No. No. 4 has Mw of 48,542, PDI of 1.21, and the content of each component in the polymer is 89.3 mol% (95.6% by mass) for SMA and 10.7 mol% (4.) for 2-HEMA. 4% by mass). The obtained copolymer No. Toluene was added to 4 to give a solid content concentration of 34.6% by mass.

<Preparation of aminoalkyd resin composition>
The constituents of the aminoalkyd resin, the copolymer and the acidic catalyst are mixed so as to have the formulation (solid content conversion) shown in Table 1, and the solid content concentration is further used with a solvent (toluene, n-heptane, methyl ethyl ketone). Was diluted to 1% by mass to prepare an aminoalkyd resin composition.

Tessfine (registered trademark) 305: A composition containing a component of a long-chain alkyl-containing aminoalkyd resin manufactured by Hitachi Chemical Co., Ltd., a solvent (toluene, methanol, xylene, isobutanol), and a solid content concentration of 50% by mass.
Uban (registered trademark) 20SE60: Mitsui Chemicals, butylated melamine resin, solvent (n-butanol, xylene, ethylbenzene), solid content concentration 60% by mass
Dryer 900: Acid catalyst manufactured by Hitachi Chemical Co., Ltd. (toluene solution of paratoluenesulfonic acid, solid content concentration 50% by mass)

<Making a mold release sheet>
An aminoalkyd resin composition is applied to a PET (polyethylene terephthalate) film "E5100" (manufactured by Toyobo Co., Ltd., thickness 50 μm) using a wire bar so that the thickness after drying is 0.1 μm, and the temperature is 150 ° C. for 30 seconds. The mold was dried and cured with a mold release sheet. The evaluation results of the obtained mold release sheet are shown in Table 1.

Release sheet No. In 1 to 7, the release agent layer is a structural unit (b) derived from an A block having a structural unit (a-1) represented by the general formula (1) and a (meth) acrylic monomer having a reactive functional group. It is formed from an aminoalkido resin composition containing a block copolymer having a B block having -1). These release sheet Nos. Nos. 1 to 7 are excellent in heat resistance, strength and appearance of the release agent layer, have a small normal peeling force, and have a high residual adhesion rate. Furthermore, these release sheet Nos. In Nos. 1 to 7, the increase in peeling force was suppressed even when exposed to a high temperature in contact with the pressure-sensitive adhesive. In addition, these release sheet Nos. Nos. 1 to 7 could be satisfactorily peeled off from the adhesive layer even after the adhesive layer formed on the release sheet was transferred to the copper foil and then stored for 30 minutes or 2 weeks.

Release sheet No. No. 8 is formed from an aminoalkyd resin composition in which the release agent layer does not contain a (meth) acrylic copolymer. This release sheet No. No. 8 has a large normal peeling force and a low residual adhesion rate. In addition, this release sheet No. In No. 8, after the adhesive layer formed on the release sheet was transferred to the copper foil, it could not be easily peeled off from the adhesive layer.

Release sheet No. In Nos. 9 and 10, the release agent layer is formed of a composition containing no constituents of the aminoalkyd resin. These release sheet Nos. In Nos. 9 and 10, the strength of the release agent layer is inferior, and the residual adhesion rate is low. In addition, these release sheet Nos. In Nos. 9 and 10, after the adhesive layer formed on the release sheet was transferred to the copper foil, it could not be easily peeled off from the adhesive layer.

Release sheet No. No. 11 is a case where the (meth) acrylic copolymer blended in the aminoalkyd resin composition forming the release agent layer is a random copolymer. This release sheet No. In No. 11, the normal peeling force is small, but the residual adhesion rate is low. In addition, this release sheet No. No. 11 greatly increased the peeling force when exposed to a high temperature in contact with the pressure-sensitive adhesive.

The present invention includes the following aspects.

(Aspect 1) The substrate sheet has a release agent layer formed on at least one surface of the substrate sheet, and the release agent layer contains a (meth) acrylic block copolymer. The (meth) acrylic block copolymer is formed from an aminoalkyd resin composition, and the (meth) acrylic block copolymer has an A block having a structural unit (a-1) represented by the general formula (1) and a reactive functional group. A release sheet comprising a block copolymer having a B block having a structural unit (b-1) derived from a (meth) acrylic monomer having the above.

(Aspect 2)
The release sheet according to aspect 1, wherein the content of the structural unit (a-1) is 40% by mass or more in 100% by mass of A block.

(Aspect 3)
The release sheet according to aspect 1 or 2, wherein the mass ratio (A block / B block) of A block to B block in the block copolymer is 80/20 to 99.99 / 0.01.

(Aspect 4)
The release sheet according to any one of aspects 1 to 3, wherein the aminoalkyd resin composition contains a melamine resin as a constituent component of the aminoalkyd resin.

(Aspect 5)
The item according to any one of aspects 1 to 4, wherein the content of the block copolymer in the aminoalkyd resin composition is 1 part by mass to 50 parts by mass with respect to 100 parts by mass of the constituent components of the aminoalkyd resin. Release sheet.

(Aspect 6)
The release sheet according to any one of aspects 1 to 5, wherein the aminoalkyd resin composition contains an acidic catalyst.

(Aspect 7)
The release sheet according to any one of aspects 1 to 6, wherein the block copolymer is obtained by living radical polymerization and has a molecular weight distribution (Mw / Mn) of 3.0 or less.

(Aspect 8)
The release sheet according to any one of aspects 1 to 7, which is used for applications exposed to an atmosphere of 100 ° C. or higher while being attached to an adhesive layer or an adhesive layer.

(Aspect 9)
^{R 11} in the formula (1) is an alkyl group having 14 to 26 carbon atoms.
The release sheet according to any one of aspects 1 to 8, wherein the content of the structural unit (a-1) is 80% by mass or more in 100% by mass of A block.

(Aspect 10)
As the structural unit (a-1), the A block is a structural unit (a-1-1) represented by the formula (1-1) and a structural unit (a-) represented by the formula (1-2). The release sheet according to any one of aspects 1 to 9 containing 1-2).

Claims (8)

1. It has a base sheet and a mold release agent layer formed on at least one surface of the base sheet.
   The release agent layer is formed of an aminoalkyd resin composition containing a (meth) acrylic block copolymer.
   The (meth) acrylic block copolymer is a structural unit derived from an A block having a structural unit (a-1) represented by the general formula (1) and a (meth) acrylic monomer having a reactive functional group. A release sheet characterized by being a block copolymer having a B block having (b-1).
   

   

   [In the formula (1), R ¹¹ represents an alkyl group having 12 to 28 carbon atoms. R ¹² represents a hydrogen atom or a methyl group. ]
2. The release sheet according to claim 1, wherein the content of the structural unit (a-1) is 40% by mass or more in 100% by mass of A block.
3. The release sheet according to claim 1 or 2, wherein the mass ratio (A block / B block) of A block and B block in the block copolymer is 80/20 to 99.99 / 0.01.
4. The release sheet according to any one of claims 1 to 3, wherein the aminoalkyd resin composition contains a melamine resin as a constituent component of the aminoalkyd resin.
5. The item according to any one of claims 1 to 4, wherein the content of the block copolymer in the aminoalkyd resin composition is 1 part by mass to 50 parts by mass with respect to 100 parts by mass of the constituent components of the aminoalkyd resin. The described release sheet.
6. The release sheet according to any one of claims 1 to 5, wherein the aminoalkyd resin composition contains an acidic catalyst.
7. The release sheet according to any one of claims 1 to 6, wherein the block copolymer is obtained by living radical polymerization and its molecular weight distribution (Mw / Mn) is 3.0 or less.
8. The release sheet according to any one of claims 1 to 7, which is used for applications exposed to an atmosphere of 100 ° C. or higher while being attached to an adhesive layer or an adhesive layer.