WO2019004209A1

WO2019004209A1 - Releasable film

Info

Publication number: WO2019004209A1
Application number: PCT/JP2018/024187
Authority: WO
Inventors: 拓明上田
Original assignee: 王子ホールディングス株式会社
Priority date: 2017-06-27
Filing date: 2018-06-26
Publication date: 2019-01-03

Abstract

Provided is a releasable film having a surface layer formed on a base layer, wherein a component contained therein rarely migrates into an object and the difference in release power before and after heating is small. A releasable film having a surface layer formed on a base layer, wherein the main component composing the surface layer is a resin component, the resin component contains a modified acrylic resin (A) that has an alkyl component and a crosslinkable functional group, a resin (B) that is different from the modified acrylic resin (A), and a cross-linking agent (D), the modified acrylic resin (A) contains at least a structural unit represented by general formula (I) (wherein R1 represents a methyl group or a hydrogen atom; and R2 represents an alkyl group having 10 to 18 carbon atoms), and the cross-linking agent (D) is a melamine compound having a structure such that each of hydrogen atoms in an amino group is substituted by an alkoxy alkyl group and/or an alkanol group.

Description

Peelable film

The present invention relates to a peelable film and a method of manufacturing the same.

Peelable films are used in industrial fields such as production processes of electronic parts and electronic substrates, and production processes of thermosetting resin members such as fiber reinforced plastics, and further in medical fields such as wet cloths and bandages.

As such a peelable film, for example, one used as a surface protective film or an adhesive tape, one used as a release liner, a separator film, etc., a manufacturing process of a semiconductor product (dicing, die bonding, back grinding And the like, carriers for forming unsintered sheets at the time of producing ceramic capacitors, carriers at the time of producing composite materials, separator films of protective materials, and the like are known.

For example, silicone-based peelable films are excellent in weather resistance, heat resistance, cold resistance, chemical resistance, and electrical insulation, and are widely used as peelable films. However, when using a silicone-based peelable film, silicone may be transferred (migrated) to an article to be attached to the film (this problem is also referred to as a silicone migration problem). Therefore, it has been studied to improve the composition of silicone in the silicone-based releasable film, to minimize the amount of silicone used, or not to use silicone. For example, Patent Document 1 proposes a release film using a hydroxy group-containing long chain alkyl polymer.

Unexamined-Japanese-Patent No. 2015-030795

However, since the peeling film described in Patent Document 1 has a large difference in peeling force before and after heating, the heat resistance is insufficient. As an example, the case where a peeling film is used as a carrier for forming an unfired sheet at the time of producing a ceramic capacitor will be described. In order to produce the said unbaked sheet, a coating layer is provided on a peeling film and it is made to dry. If the heat resistance is insufficient because the difference in peel strength before and after heating is large, the unbaked sheet is unlikely to be suddenly peeled from the peel film by the heat of drying after the drying. Depending on the release film, the unbaked sheet may not only be unexpectedly difficult to be removed from the release film, but it may be considered that the unbaked sheet may be unexpectedly removed from the release film. Because of these problems, the release film is difficult to use as a substitute film for silicone-based release films.

Also, similar to the problem of silicone migration by the silicone-based peelable film, when the components of the peelable film migrate to the surface of the article and peel the peelable film from the article, the components of the peelable film remain on the surface of the article There is a problem that the surface of the article is contaminated. The residual components of the surface of the article not only contaminate the surface of the article but also lead to the contamination of the surface of other articles which are subsequently in contact with the article, and in particular, the manufacturing process of precision devices such as electronic components and electronic substrates The releasable film to be used for the above is required to have a performance that makes it difficult for the components of the releasable film to transfer to the article.

Under such circumstances, the main object of the present invention is to provide a peelable film in which the components of the peelable film are less likely to transfer to the article and the difference in peel force before and after heating is small.

Moreover, the peeling film described in patent document 1 has large peeling force, and heat resistance is inadequate. Therefore, there is still a need for a peelable film that has good peelability that the peel strength is light and that is excellent in heat resistance (maintaining the above-mentioned good peelability even after heat treatment).

An object of the second embodiment is to provide a peelable film excellent in heat resistance, as well as having good peelability that the peel force is light.

The present inventors diligently studied to solve the above-described problem of the first embodiment. As a result, it is a peelable film having a surface layer on a base material layer, wherein the main component forming the surface layer is a resin component, and the resin component is a modified acrylic resin having an alkyl component and a crosslinkable functional group. (A), a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D), and the modified acrylic resin (A) contains at least the following general formula (I):

(In the above general formula (I), R ¹ represents a methyl group or a hydrogen atom, and R ² represents an alkyl group having 10 to 18 carbon atoms.)
And the crosslinker (D) is a melamine compound having a structure in which all hydrogen atoms of the amino group are substituted with at least one of an alkoxyalkyl group and an alkanol group. It was found that the film was difficult to transfer the components of the peelable film to the article, and the difference in peel force before and after heating was small. The first embodiment is completed by further studying based on such findings.

That is, the following are included in the first embodiment.
[1] A peelable film having a surface layer on a substrate layer,
The main component forming the surface layer is a resin component,
The resin component includes a modified acrylic resin (A) having an alkyl component and a crosslinkable functional group, a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D).
The modified acrylic resin (A) has at least the following general formula (I):

(In the above general formula (I), R ¹ represents a methyl group or a hydrogen atom, and R ² represents an alkyl group having 10 to 18 carbon atoms.)
Contains the constitutional unit represented by
The crosslinkable agent (D) is a releasable film, wherein the crosslinker (D) is a melamine compound having a structure in which all hydrogen atoms of an amino group are substituted with at least one of an alkoxyalkyl group and an alkanol group.
[2] The modified acrylic resin (A) has the following general formula (II):

[In the above general formula (II), R ^a represents a methyl group or a hydrogen atom, R ^b represents -CH ₂ CH ₂ OH, -CH ₂ -CHOH-CH ₃ , -CH ₂ CH ₂ CH ₂ OH, -CH ₂ -CHOH-CH ₂ CH ₃ , -CH ₂ CH ₂ -CHOH-CH ₃ , or -CH ₂ CH ₂ CH ₂ CH ₂ OH is shown. ]
The peelable film of claim | item 1 containing the structural unit represented by these.
[3] The releasable film according to item 1 or 2, wherein the weight average molecular weight of the modified acrylic resin (A) is 5 × 10 ⁴ to 15 × 10 ⁴ .
[4] The content of the resin (B) in the surface layer is 2 parts by mass or more based on 100 parts by mass of the total of the modified acrylic resin (A) and the resin (B) constituting the surface layer. The peelable film according to any one of Items 1 to 3, which is
[5] The content of the resin (B) in the surface layer is less than 50 parts by mass based on 100 parts by mass of the total of the modified acrylic resin (A) and the resin (B) constituting the surface layer. The peelable film according to any one of Items 1 to 4, which is
[6] The peelable film according to any one of Items 1 to 5, wherein the alkoxyalkyl group has 2 to 5 carbon atoms, and the alkanol group has 1 to 3 carbon atoms.
[7] The resin according to any one of items 1 to 6, wherein the resin (B) different from the modified acrylic resin (A) is at least one selected from the group consisting of a polyester resin and an acrylic resin. Peelable film.
[8] A method for producing a peelable film having a surface layer on a substrate layer,
Forming the surface layer on the base layer,
The main component forming the surface layer is a resin component,
The resin component includes a modified acrylic resin (A) having an alkyl component and a crosslinkable functional group, a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D).
The modified acrylic resin (A) has at least the following general formula (I):

(In the above general formula (I), R ¹ represents a methyl group or a hydrogen atom, and R ² represents an alkyl group having 10 to 18 carbon atoms.)
Contains the constitutional unit represented by
The method for producing a release film, wherein the crosslinking agent (D) is a melamine compound having a structure in which all hydrogen atoms of amino groups are substituted with at least one of alkoxyalkyl groups and alkanol groups.

In addition, the present inventors diligently studied to solve the above-mentioned problem of the second embodiment. As a result, it is a peelable film having a surface layer on a substrate layer, wherein the content of carbon relative to the total elemental content present at a depth of 5 nm vertically from the outermost surface in the surface layer toward the substrate layer The peelable film having a content ratio M _C5 (atomic%) of 98 or more was found to be excellent in heat resistance as well as having good peelability (that is, light in peel strength). The second embodiment is completed by further studying based on such findings.

That is, the second embodiment includes the following.
[9] A peelable film having a surface layer on a substrate layer,
A peelable film having a carbon content ratio _MC5 (atomic%) to a total elemental content present at a depth of 5 nm vertically from the outermost surface in the surface layer toward the base material layer.
[10] The main component forming the surface layer is a resin component,
The resin component includes a modified acrylic resin (A) having an alkyl component and a crosslinkable functional group, a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D).
The modified acrylic resin (A) has at least the following general formula (I):

(In the above general formula (I), R ¹ represents a methyl group or a hydrogen atom, and R ² represents an alkyl group having 10 to 18 carbon atoms.)
10. The peelable film according to item 9, comprising a structural unit represented by
[11] The content of the resin (B) in the surface layer is 2 parts by mass or more based on 100 parts by mass of the total of the modified acrylic resin (A) and the resin (B) constituting the surface layer. 11. The peelable film according to item 10.
[12] The content of the resin (B) in the surface layer is less than 50 parts by mass based on 100 parts by mass of the total of the modified acrylic resin (A) and the resin (B) constituting the surface layer. 12. The peelable film according to item 10 or 11.
[13] The _{MC 5} and the carbon content ratio _{MC 40} (atomic%) to the total element content present at a depth of 40 nm vertically from the outermost surface in the surface layer toward the base material layer The peelable film according to any one of Items 9 to 12, wherein the ratio M _C5 / M _C40 is 1.01 ≦ M _C5 / M _C40 ≦ 1.10.
[14] The resin according to any one of items 9 to 13, wherein the resin (B) different from the modified acrylic resin (A) is at least one selected from the group consisting of a polyester resin and an acrylic resin. Peelable film.

According to the first embodiment, it is a peelable film having a surface layer on a base material layer, in which the components of the peelable film are less likely to transfer to the article, and the difference in peel force before and after heating is small. Can be provided.

According to the second embodiment, it is possible to provide a peelable film having excellent peelability that the peel force is light and also excellent in heat resistance. Therefore, it is particularly suitable as a release film or the like used in the process of producing an electronic component or an electronic substrate, or in the process of producing a thermosetting resin member such as a fiber reinforced plastic.

Hereinafter, the first embodiment will be described first, and then the second embodiment will be described. In the description of the second embodiment, the descriptions overlapping with the first embodiment will be omitted as appropriate.

First Embodiment
The releasable film according to the first embodiment is a releasable film having a surface layer on a base material layer, and the main component forming the surface layer is a resin component, and the resin component is an alkyl component and a crosslink Containing a modified acrylic resin (A) having a functional functional group, a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D), the modified acrylic resin (A) comprising at least , The following general formula (I):

(In the above general formula (I), R ¹ represents a methyl group or a hydrogen atom, and R ² represents an alkyl group having 10 to 18 carbon atoms.) Containing a constitutional unit (repeating unit) The crosslinking agent (D) is characterized in that it is a melamine compound having a structure in which all hydrogen atoms of the amino group are substituted with at least one of an alkoxyalkyl group and an alkanol group.

By having such a configuration, the peelable film according to the first embodiment exhibits the characteristic that the components of the peelable film do not easily transfer to the article, and the difference in peel force before and after heating is small. More specifically, (1) when an object (adherend) is attached to the surface layer of the peelable film and then peeled off between the surface layer and the object, peelability The component contained in the surface layer of the film does not easily migrate to the surface of the object, and (2) it also exhibits the characteristic that the difference in peel force before and after being heated to a high temperature such as 90 to 160 ° C is small. . Since the peelable film according to the first embodiment has these characteristics, the process of producing an electronic component, an electronic substrate, etc., the process of producing a thermosetting resin member such as fiber reinforced plastic, Can be suitably used in the medical field such as poultices and bandages. The peelable film according to the first embodiment has not only the above-mentioned properties but also a low peel strength at normal temperature (peel force before being heated to the above-described high temperature) and / or excellent residual adhesion. In the above-mentioned fields, it can be further preferably used.

Hereinafter, the peelable film which concerns on 1st Embodiment is explained in full detail. In the present specification, the numerical range “to” means the above and the following. That is, the notation α to β means α or more and β or less, or β or more and α or less, and includes α and β as a range. Also, "(meth) acrylic" means "acrylic or methacrylic", and other similar ones mean the same.

The peelable film according to the first embodiment is a laminated film having a base material layer and a surface layer on at least one side of the base material layer.

[Base material layer]
As the base material layer, in addition to a layer containing a resin (example: a film made of resin), thin sheets of paper, non-woven fabric, metal foil and the like can be used. When the base material layer is a layer containing, for example, a resin, the resin may be, for example, a polyester resin such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene terephthalate, polypropylene naphthalate, polytrimethylene terephthalate, or polybutylene terephthalate. Polyolefin resins such as polyethylene and polypropylene; polystyrene resins; acetyl cellulose resins such as triacetyl cellulose; acrylic resins such as polymethyl methacrylate; polyurethane resins; polycarbonate resins; polyamide resins; polyvinyl chloride resins etc. It is a layer containing.

When the base material layer is a layer containing a resin, only one type of the above-mentioned resin may be contained, or two or more types may be contained in combination. The base material layer in the peelable film of the first embodiment contains, as a main component, at least one selected from the group consisting of polyester resins, polyolefin resins, and polystyrene resins from the viewpoint of processability of the surface layer. A polyester resin from the viewpoint of adhesion to the surface layer (also adhesion to another layer when another layer is interposed between the surface layer and the base layer), It is more preferable that the layer contains, as a main component, at least one selected from the group consisting of and polyolefin resins.

Here, in the present invention and the present specification, the main component means a component contained at 50% by mass or more, and the ratio of the main component is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably It is 90% by mass or more, particularly preferably 95% by mass or more. In addition, 100 mass% may be sufficient as the ratio of the said main component.

An additive may be contained in the base material layer similarly to the surface layer mentioned later. The types and components of the additives are the same as those described in the item of the surface layer described later, and the description thereof is omitted here.

The base material layer may be a layer constituted of any of a non-oriented film, a uniaxially oriented film, and a biaxially oriented film. From the viewpoint of processability, transparency and dimensional stability, the base material layer is preferably a layer composed of a biaxially stretched film.

The thickness of the base material layer is preferably 15 μm or more, more preferably 20 μm or more, from the viewpoint of processability. The thickness of the base material layer is preferably 125 μm or less, more preferably 50 μm or less, from the viewpoint of handling when using the product. The thickness of the base material layer is measured according to JIS C-2151 using a micrometer (JIS B-7502), and specifically, it is measured by the method described in the examples.

For the purpose of enhancing the adhesion between the substrate layer and the surface layer described later, one or both surfaces of the substrate layer may be subjected to surface treatment, if desired. Examples of surface treatment include surface roughening treatment such as sand blasting treatment or solvent treatment, surface treatment such as corona discharge treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, or ozone / ultraviolet radiation treatment. .

[Surface layer]
The peelable film of the first embodiment has a surface layer on a base material layer. The surface layer is a layer for imparting releasability to the releasable film. The surface layer may be formed on the base material layer through each layer such as an adhesive layer between the base layer and the base layer, but the main surface of the surface layer is in contact with the main surface of the base material layer. Preferably, a surface layer is formed.

The main component forming the surface layer is a resin component. Further, the resin component contains a modified acrylic resin (A) having an alkyl component and a crosslinkable functional group, a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D). . That is, the surface layer comprises a modified acrylic resin (A) having an alkyl component and a crosslinkable functional group as a resin component, a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D). It is comprised by the hardened | cured material of the resin composition containing. Hereinafter, the modified acrylic resin (A), the resin (B) different from the modified acrylic resin (A), and the crosslinking agent (D) will be described in detail.

<Modified acrylic resin (A)>
The modified acrylic resin (A) having an alkyl component and a crosslinkable functional group is a resin having an alkyl group as a side chain with respect to the main chain acrylic resin. The modified acrylic resin (A) contains at least a structural unit (formed by a monomer a described below) represented by the following general formula (I).

In the general formula (I), R ¹ represents a methyl group or a hydrogen atom, and R ² represents an alkyl group having 10 to 18 carbon atoms.

In the general formula (I), the carbon number of the alkyl group R ² is 10 to 18. When the carbon number is less than 9, it is generally difficult to cause the modified acrylic resin (A) to exhibit releasability. In addition, when the carbon number exceeds 18, the peelability becomes too high due to the high crystallinity and the like, and the peelability as a peelable film is inferior. When the modified acrylic resin (A) has a long-chain alkyl group having 10 to 18 carbon atoms, the peeling performance is excellent. In order to improve the release performance, it is preferred that R ² in the general formula (I) is a straight chain alkyl group. In addition, the carbon number of R ² is preferably 12 to 18, and more preferably 12 to 14. R ² is more preferably a linear alkyl group having 12 to 18 carbon atoms, and particularly preferably a linear alkyl group having 12 to 14 carbon atoms.

In the modified acrylic resin (A), as the crosslinkable functional group (reactive functional group), for example, carboxyl group, isocyano group, epoxy group, N-methylol group, N-alkoxymethyl group, hydroxy group, amino group, A thiol group, a hydrolyzable silyl group, etc. are mentioned. The number of crosslinkable functional groups may be one or two or more. The crosslinkable functional group may be contained singly or in combination of two or more.

The modified acrylic resin (A) is at least a monomer a (constituting a carbon-carbon unsaturated double bond in one molecule) which forms a constitutional unit represented by the above general formula (I) as a monomer And an acrylic monomer having an alkyl group of 10 to 18 carbon atoms). The modified acrylic resin (A) is, together with the monomer a, a monomer b described later (a monomer having a carbon-carbon unsaturated double bond and a crosslinkable functional group in one molecule), a single monomer b, A monomer c (an acrylic monomer having a carbon-carbon unsaturated double bond and an alkyl group having 1 to 9 or 19 or more carbon atoms in one molecule), and a monomer d (monomers a and b) And c are at least one monomer selected from the group consisting of monomers different from at least one of monomers a, b and c). It may be a copolymer obtained by polymerization. In particular, a copolymer obtained by copolymerizing at least the monomer a and the monomer b is preferable as the modified acrylic resin (A).

[Monomer a]
Examples of the monomer a include (meth) acrylic esters in which the ester moiety is a long-chain alkyl group having 10 to 18 carbon atoms. Specifically, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate (also referred to as lauryl (meth) acrylate), tridecyl (meth) acrylate and tetradecyl (meth) acrylate (myristyl (meth) acrylate) And pentadecyl (meth) acrylate, hexadecyl (meth) acrylate (also referred to as palmityl (meth) acrylate), stearyl (meth) acrylate and the like.

The content ratio of the structural unit derived from the monomer a in the modified acrylic resin (A) reduces the difference in peel force before and after heating, and further, from the viewpoint of making it difficult to transfer the components of the surface layer to the article, modification The total of structural units contained in the acrylic resin (A) is preferably about 50 to 99.99 parts by mass, more preferably about 70 to 99.9 parts by mass, and still more preferably 85 to 99.8 parts by mass. The amount is about the part by mass, more preferably 85 to 99.5 parts by mass. As the monomer a, only one type may be used, or two or more types may be mixed and used.

[Monomer b]
The monomer b is a monomer having a carbon-carbon unsaturated double bond and a crosslinkable functional group in one molecule. Since the monomer b has a crosslinkable functional group, it is suitably bonded to a resin (B) or the like different from the modified acrylic resin (A) via a crosslinking agent (D) described later, The difference in peel force before and after heating of the peelable film can be reduced, and furthermore, the transfer of the components of the surface layer to the article can be suppressed.

As a crosslinkable functional group (reactive functional group), for example, carboxyl group, isocyano group, epoxy group, N-methylol group, N-alkoxymethyl group, hydroxy group, amino group, thiol group, hydrolyzable silyl group, etc. Can be mentioned. As the monomer b, only one type may be used, or two or more types may be mixed and used. In the monomer b, the number of crosslinkable functional groups may be one or two or more. The crosslinkable functional group may be contained singly or in combination of two or more.

Examples of the monomer b having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid and styrene sulfonic acid. Further, as the monomer b having a carboxyl group, N- (meth) acryloyl-p-aminobenzoic acid, N- (meth) acryloyl-5-aminosalicylic acid and the like can also be mentioned. Moreover, a carboxyl group-containing (meth) acrylate is also mentioned as monomer b which has a carboxyl group. As the carboxyl group-containing (meth) acrylate, 1,4-di (meth) acryloxyethyl pyromellitic acid, 4- (meth) acryloxyethyl trimellitic acid, 2- (meth) acryloyl oxybenzoic acid and the like can be mentioned. .

As the monomer b having an isocyano group, (meth) acryloyloxyethyl isocyanate, (meth) acryloyloxypropyl isocyanate, etc. may be mentioned, and hydroxy (meth) acrylate (eg, 2-hydroxyethyl (meth) acrylate, What is obtained by reacting 4-hydroxybutyl (meth) acrylate and the like with a polyisocyanate (for example, toluene diisocyanate, isophorone diisocyanate and the like) may also be mentioned.

Examples of the monomer b having an epoxy group include glycidyl methacrylate, glycidyl cinnamate, glycidyl allyl ether, glycidyl vinyl ether, vinylcyclohexane monoepoxide, 1,3-butadiene monoepoxide and the like.

As a monomer b having an N-methylol group or an N-alkoxymethyl group, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-propoxymethyl ( (Meth) acrylamide, N-monoalkoxymethyl-containing (meth) acrylamide such as N-butoxymethyl (meth) acrylamide, N, N-dimethylol (meth) acrylamide, N, N-di (methoxymethyl) (meth) acrylamide N, N-dialkoxy such as N, N-di (ethoxymethyl) (meth) acrylamide, N, N-di (propoxymethyl) (meth) acrylamide, N, N-di (butoxymethyl) (meth) acrylamide and the like (Meth) acrylamide having a methyl group is mentioned .

As the monomer b having a hydroxy group, a hydroxy group-containing (meth) acrylate is mainly mentioned. As a hydroxy group-containing (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 1-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono ( Examples include meta) acrylates, polypropylene glycol mono (meth) acrylates, polytetramethylene glycol mono (meth) acrylates, and the like. In addition, as the monomer b having a hydroxy group, hydroxystyrene and the like can also be mentioned.

Examples of the monomer b having an amino group include primary or secondary amino group-containing (meth) acrylates. Examples of primary or secondary amino group-containing (meth) acrylates include aminoethyl (meth) acrylate, ethylaminoethyl (meth) acrylate, aminopropyl (meth) acrylate and ethylaminopropyl (meth) acrylate. .

Examples of the monomer b having a thiol group include thiol group-containing (meth) acrylates. Examples of thiol group-containing (meth) acrylates include 2- (methylthio) ethyl methacrylate.

Examples of the monomer b having a hydrolyzable silyl group include (meth) acryloxyalkylalkoxysilanes such as γ- (meth) acryloxypropyltrimethoxysilane and γ- (meth) acryloxypropylmethyldimethoxysilane, (meth Acryloxyalkylalkoxyalkylsilane, trimethoxyvinylsilane, dimethoxyethylsilane, triethoxyvinylsilane, triethoxyallylsilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, vinyltris (2-methoxyethoxy) silane and the like.

As monomer b, preferably, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl At least one selected from the group consisting of (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polytetramethylene glycol mono (meth) acrylate and hydroxystyrene It is one kind, more preferably 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxy Butyl (meth) acrylate is at least one selected from the group consisting of 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate.

Monomer b is 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, And when it is at least one selected from the group consisting of 4-hydroxybutyl (meth) acrylate, the modified acrylic resin (A) contains at least the constituent unit represented by the above general formula (I), and at least The structural unit represented by the following general formula (II) is included.

In the general formula (II), R ^a represents a methyl group or a hydrogen atom, and R ^b represents -CH ₂ CH ₂ OH, -CH ₂ -CHOH-CH ₃ , -CH ₂ CH ₂ CH ₂ OH, -CH _{_{_{2 -CHOH-CH 2 CH 3,}}} -CH 2 CH 2 -CHOH-CH 3, or an _{_{_{_{-CH 2 CH 2 CH 2 CH 2}}}} OH.

When the modified acrylic resin (A) contains a constitutional unit derived from the monomer b, the content ratio of the constitutional unit derived from the monomer b in the modified acrylic resin (A) is the peel strength before and after heating. From the viewpoint of reducing the difference and further making it difficult to transfer the components of the surface layer to the article, the amount of the total of structural units contained in the modified acrylic resin (A) is about 0.01 to 20 parts by mass with 100 parts by mass. Is preferably about 0.1 to 10 parts by mass, more preferably about 0.2 to 5 parts by mass, still more preferably about 0.5 to 3 parts by mass, 0. It is particularly preferable that the amount is about 8 to 1.5 parts by mass. When the modified acrylic resin (A) contains not only a structural unit derived from the monomer a but also a structural unit derived from the monomer b, the primary structure may be a random copolymer, It may be a block copolymer.

[Monomer c]
The monomer c is an acrylic monomer having a carbon-carbon unsaturated double bond and an alkyl group having 1 to 9 or 19 or more carbon atoms in one molecule. The monomer c can be used, for example, to adjust the concentration of the alkyl group contained in the surface layer, reduce the difference in peel strength before and after heating of the peelable film, and further, an article of the component of the surface layer It can contribute to the suppression of the transition to

As the monomer c, (meth) acrylic acid derivatives are preferably mentioned. As the (meth) acrylic acid derivative, a monomer from which a structural unit represented by the following general formula (III) can be derived is preferable.

In the general formula (III), R ¹ represents a methyl group or a hydrogen atom, R ³ represents an alkyl group having 1 to 9 or 19 or more carbon atoms, and the alkyl group is a fluorine atom, an oxygen atom or a nitrogen atom Or a modified alkyl group containing a sulfur atom, a chlorine atom, a bromine atom, a silicon atom or the like.

Specific examples of the monomer c include methyl (meth) acrylate, butyl (meth) acrylate, n-octyl (meth) acrylate, nonyl (meth) acrylate stearyl (meth) acrylate, ethylhexyl (meth) acrylate, benzyl (meth) ) Acrylate, (meth) acrylate, (meth) acrylonitrile and the like. The monomer c may be used alone or in combination of two or more.

When the modified acrylic resin (A) contains a constitutional unit derived from the monomer c, the content ratio of the constitutional unit derived from the monomer c in the modified acrylic resin (A) is the peel strength before and after heating. From the viewpoint of reducing the difference and further making it difficult to transfer the components of the surface layer to the article, the amount of the total of structural units contained in the modified acrylic resin (A) is about 0.01 to 20 parts by mass with 100 parts by mass. The content is preferably about 0.1 to 10 parts by mass.

[Monomer d]
The monomer d is a monomer different from the monomers a, b and c, and is a monomer copolymerizable with at least one of the monomers a, b and c.

Specific examples of the monomer d include (i ′) aromatic vinyl monomer, (ii ′) olefin hydrocarbon monomer, (iii ′) vinyl ester monomer, and (iv ′) vinyl Halide monomers, (v ') vinyl ether monomers, etc. may be mentioned. As the monomer d, only one type may be used, or two or more types may be mixed and used. The monomer d can be used, for example, to adjust the concentration of various functional groups contained in the surface layer, and the difference in the peeling force before and after heating of the peelable film is small. It can contribute to the suppression of the transition to goods.

As the aromatic vinyl monomer, styrene, methylstyrene, ethylstyrene, chlorostyrene, styrenes partially substituted with hydrogen (eg, monofluoromethylstyrene, difluoromethylstyrene, trifluoromethylstyrene etc.), etc. Can be mentioned.

The olefin hydrocarbon monomer may, for example, be ethylene, propylene, butadiene, isobutylene, isoprene or 1,4-pentadiene.

Examples of the vinyl ester monomer include vinyl acetate and the like.

Examples of the vinyl halide monomer include vinyl chloride, vinylidene chloride, monofluoroethylene, difluoroethylene, trifluoroethylene and the like.

Examples of vinyl ether monomers include vinyl methyl ether and the like.

When the modified acrylic resin (A) contains a constitutional unit derived from the monomer d, the content ratio of the constitutional unit derived from the monomer d in the modified acrylic resin (A) is the peel strength before and after heating. From the viewpoint of reducing the difference and further making it difficult to transfer the components of the surface layer to the article, the amount of the total of structural units contained in the modified acrylic resin (A) is about 0.01 to 20 parts by mass with 100 parts by mass. The content is preferably about 0.1 to 10 parts by mass.

The weight average molecular weight of the modified acrylic resin (A) is preferably 5 × 10 ⁴ to 15 × 10 in order to reduce the difference in peel force before and after heating and to make it difficult to transfer the components of the surface layer to the article. ^4, and more preferably from ^{6 × 10 4 ~ 14 × 10} 4, more preferably from ^{8 × 10 4 ~ 12 × 10} 4.

The content of the modified acrylic resin (A) in the surface layer is not particularly limited, but from the viewpoint of reducing the difference in peel force before and after heating and making it difficult to transfer the components of the surface layer to the article, the surface The total amount of the resin (A) and the resin (B) constituting the layer is 100 parts by mass, preferably 30 parts by mass or more, more preferably 40 parts by mass or more, further preferably 50 parts by mass or more, and more than 50 parts by mass It is more preferable, and 55 parts by mass or more is particularly preferable. In addition, the content of the modified acrylic resin (A) in the surface layer is preferably 98 parts by mass or less with respect to a total of 100 parts by mass of the resin (A) and the resin (B) constituting the surface layer. It is more preferably 90 parts by mass or less, still more preferably 80 parts by mass or less, particularly preferably 70 parts by mass or less, and particularly preferably 60 parts by mass or less.

As a method of obtaining the modified acrylic resin (A), the above-mentioned monomer a and, if necessary, monomer b, monomer c and monomer d, radical polymerization, anion polymerization, cation polymerization etc. It can be obtained by polymerization by a known polymerization method.

During polymerization, an initiator may be used. As an initiator, an azo compound, an organic peroxide, etc. can be used. Among them, an azo compound is preferable, and azobisisobutyronitrile (AIBN) is more preferable, from the viewpoint of polymerization yield and easiness of molecular weight control. The amount of the polymerization agent used is preferably 0.01 to 3 parts by mass, taking 100 parts by mass as the total of structural units contained in the modified acrylic resin (A), from the viewpoint of yield and ease of control of molecular weight. It is preferably 2 to 2 parts by mass, more preferably 0.1 to 1.5 parts by mass.

In addition, the modified acrylic resin (A) is an alkyl group to a polymer obtained by polymerizing at least the monomer b (a monomer having a carbon-carbon unsaturated double bond and a crosslinkable functional group). May be obtained by graft polymerization. That is, a polymer (hereinafter referred to as a modified acrylic resin (A ')) having a structure in which an alkyl group is graft-polymerized to a part or all of the crosslinkable functional group of the constituent unit derived by monomer b Similar to the modified acrylic resin (A), it can be used alone or in combination with the modified acrylic resin (A).

In the modified acrylic resin (A ′), the carbon number of the graft-polymerized alkyl group is preferably about 10 to 18, and more preferably about 12 to 14. The method for introducing the alkyl group by graft polymerization is not limited, and a known method may be mentioned.

Also in the modified acrylic resin (A '), the same as the monomer b exemplified for the modified acrylic resin (A) can be preferably used. The details of the monomer b are as described above.

The modified acrylic resin (A ′) may be a copolymer obtained by copolymerizing at least one of the monomer c and the monomer d with the monomer b.

Also in the modified acrylic resin (A '), the monomer c and the monomer d exemplified for the modified acrylic resin (A) can be preferably used. The details of the monomer c and the monomer d are as described above.

<Resin (B)>
The resin component which forms a surface layer contains resin (B) different from modified acrylic resin (A) with modified acrylic resin (A).

By containing the resin (B) in the surface layer, the alkyl group of the modified acrylic resin (A) can be easily segregated on the surface by utilizing the difference in compatibility with the modified acrylic resin (A), and heating It is possible to reduce the difference between the front and back peel force, and to make it difficult to transfer the components of the surface layer to the article.

The resin (B) is not particularly limited, but preferably includes at least one selected from the group consisting of polyester resins and acrylic resins. Moreover, as a polyester resin and an acrylic resin, it can select suitably from the well-known things known as a polyester resin and an acrylic resin, and can be used. For example, as a polyester resin, it is a resin obtained by condensation reaction of (i) polyhydric alcohol and polybasic acid, which is modified with a condensation product of dibasic acid and dihydric alcohol, non-drying oil fatty acid, etc. Examples include certain non-convertible polyester resins, and (ii) invertible polyester resins which are condensation products of dibasic acids and tri- or higher alcohols. In the first embodiment, only one type of polyester resin (B) may be used, or two or more types may be mixed and used.

Specifically as a polyhydric alcohol used as a raw material of polyester resin, a dihydric alcohol, a trihydric alcohol, the polyhydric alcohol more than tetravalent etc. are mentioned. Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, neopentyl glycol and the like. Examples of trihydric alcohols include glycerin, trimethylolethane, trimethylolpropane and the like. Examples of the polyhydric alcohol of tetravalent or higher include diglycerin, triglycerin, pentaerythritol, dipentaerythritol, mannit, sorbite and the like. These polyhydric alcohols may be used alone or in combination of two or more.

Further, as polybasic acids used as raw materials of polyester resin, specifically, aromatic polybasic acids, aliphatic saturated polybasic acids, aliphatic unsaturated polybasic acids, polybasic acids by Diels-Alder reaction, etc. Can be mentioned. Examples of aromatic polybasic acids include phthalic anhydride, terephthalic acid, isophthalic acid, and trimet anhydride. Examples of aliphatic saturated polybasic acids include succinic acid, adipic acid and sebacic acid. Examples of aliphatic unsaturated polybasic acids include maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic anhydride and the like. Examples of polybasic acids obtained by the Diels-Alder reaction include cyclopentadiene-maleic anhydride adduct, terpene-maleic anhydride adduct, rosin-maleic anhydride adduct and the like. These polybasic acids may be used alone or in combination of two or more.

Specific examples of the non-drying oil fatty acid which is a modifier include octylic acid, lauric acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linoleic acid, eleostearic acid, licinoleic acid, dehydrated ricinoleic acid, Or coconut oil, linseed oil, tung oil, castor oil, dehydrated castor oil, soybean oil, safflower oil, fatty acids of these, and the like. One of these may be used alone, or two or more may be used in combination. Moreover, as a polyester resin, it may be used individually by 1 type, and may be used combining 2 or more types.

Moreover, as an acrylic resin, for example, a homopolymer of (meth) acrylic acid ester, a copolymer of two or more different (meth) acrylic acid ester monomers, or (meth) acrylic acid ester and another monomer Copolymers may be mentioned. More specifically, as the (meth) acrylic resin, methyl poly (meth) acrylate, ethyl poly (meth) acrylate, propyl poly (meth) acrylate, butyl poly (meth) acrylate, (meth) acrylate Methyl (butyl) (meth) acrylate copolymer, ethyl (meth) acrylate-butyl (meth) acrylate copolymer, ethylene-methyl (meth) acrylate copolymer, styrene-(meth) acrylate co-polymer Examples thereof include (meth) acrylic acid esters such as polymers. Only one type of acrylic resin may be used, or two or more types may be mixed and used.

The resin (B) different from the modified acrylic resin (A) preferably has a reactive functional group in order to react with a crosslinking agent (D) described later. In particular, the reactive functional group is preferably at least one selected from the group consisting of a carboxyl group and a hydroxy group. When the resin (B) has a hydroxy group, the hydroxyl value of the resin (B) is preferably 5 to 500 mg KOH / g, more preferably 10 to 300 mg KOH / g, and 15 to 100 mg KOH / g. It is further preferred that

The number average molecular weight of the resin (B) is preferably about 500 to 30,000, and more preferably about 1,000 to 20,000. When the resin (B) has a number average molecular weight in the above range, the network structure when the surface layer is crosslinked with the crosslinking agent (D) is likely to be dense, and the modified acrylic having an alkyl component and a crosslinkable functional group Segregation on the release surface of the resin (A) is likely to occur.

Although the content of the resin (B) in the surface layer is not limited, the surface layer is formed from the viewpoint of reducing the difference in peel force before and after heating and making it difficult to transfer the components of the surface layer to the article. The total amount of the resin (A) and the resin (B) is preferably 2 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 20 parts by mass or more, based on 100 parts by mass. It is particularly preferable that the content is at least 40 parts by mass, and particularly preferably at least 40 parts by mass. From the same point of view, the total amount of the resin (A) and the resin (B) constituting the surface layer is preferably 100 parts by mass or less and is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, The content is more preferably 50 parts by mass or less, still more preferably less than 50 parts by mass, and particularly preferably 45 parts by mass or less.

<(D) Crosslinking agent>
The resin component which forms a surface layer contains a crosslinking agent (D) with denatured acrylic resin (A) and resin (B). The crosslinking agent (D) has a function of crosslinking the modified acrylic resins (A), the resins (B), or the modified acrylic resin (A) and the resin (B).

In a first embodiment, the crosslinker (D) is a melamine compound. The melamine compound has a structure in which all hydrogen atoms of the amino group are substituted with at least one of an alkoxyalkyl group and an alkanol group. That is, it can be said that the melamine compound has at least one selected from the group consisting of an alkoxyalkyl group and an alkanol group as a substituent of the amino group. Further, the melamine compound has a structural unit in which three amino groups are bonded to a triazine ring, and in the first embodiment, a total of six substituents bonded to three amino groups are alkoxyalkyl groups and It can be said that it is only at least one selected from the group consisting of alkanol groups, and does not have any other substituent such as a hydrogen atom.

More specifically, the melamine compound can be represented by the following general formula (IV).

In the general formula (IV), a total of six substituents R possessed by three amino groups bonded to the triazine ring are groups in which the hydrogen atoms of the amino groups are substituted. The six substituents R are each independently an alkoxyalkyl group or an alkanol group. Further, n is a number of 1 or more, and indicates the average n number of the melamine compound.

The alkoxyalkyl group means, for example, a C1-6 alkyloxy C1-6 alkyl group such as a methoxymethyl group or 1-ethoxyethyl group. The alkanol group is, for example, hydroxymethyl group, 2-hydroxyethyl group, 3-hydroxypropyl group, 2-hydroxy-n-propyl group (-CH ₂ -CHOH-CH ₃ ), 2-hydroxy-1- It means a group in which a hydrogen atom on a terminal methyl group of a linear or branched alkyl group such as a methylethyl group is substituted with a hydroxy group. Here, C1-6 means carbon number of 1 to 6.

In the first embodiment, from the viewpoint of reducing the difference in peel force before and after heating and further making it difficult to transfer the components of the surface layer to the article, the melamine compound has six substituents R in general formula (IV) Among them, at least one is preferably an alkoxyalkyl group, three or more are more preferably an alkoxyalkyl group, and it is particularly preferable that all six be an alkoxyalkyl group. In the general formula (IV), among the six substituents R, the number of alkanol groups is preferably 5 or less, more preferably 3 or less, and still more preferably 0. In the examples described later, in the melamine compound of type F, all six substituents R are alkoxyalkyl groups.

In the melamine compound, the carbon number of the alkoxyalkyl group is preferably 2 to 5, and more preferably 2. Preferred specific examples of the alkoxyalkyl group include propoxymethyl group, ethoxymethyl group, methoxymethyl group and the like, and among these, methoxymethyl group is particularly preferable. The carbon number of the alkanol group is preferably 1 to 3, and more preferably 1. Specific preferred examples of the alkanol group include propanol group (3-hydroxypropyl group), ethylol group (2-hydroxyethyl group), methylol group (hydroxymethyl group) and the like, and among these, methylol group is particularly preferable.

The average n amount number of the melamine compound is preferably about 1.0 to 3.0, more preferably about 1.1 to 2.0, and still more preferably about 1.2 to 1.5. As the crosslinking agent (D), only one type may be used, or two or more types may be mixed and used.

In the first embodiment, the melamine compound is a compound represented by the general formula (V) from the viewpoint of reducing the difference in peel force before and after heating and further making it difficult to transfer the components of the surface layer to the article. Is particularly preferred.

[Here, Me represents a methyl group. ]

In the general formula (V), the average n number of melamine compounds is in the above range.

In the first embodiment, the resin component forming the surface layer may contain another crosslinking agent different from the crosslinking agent (D), but the crosslinking agent contained in the resin component is It is preferable that it is only a crosslinking agent (D).

Other crosslinking agents include, but are not limited to, for example, polyfunctional amino compounds different from the aforementioned melamine compounds, isocyanate compounds (including monoisocyanate, diisocyanate, polyfunctional isocyanate etc.), polyfunctional epoxy compounds, polyfunctional Metal compounds or dialdehydes and the like can be mentioned.

As a polyfunctional amino compound different from the said melamine compound, a urea compound, a benzoguanamine compound, diamines etc. are mentioned. Examples of the urea compound include alkylated urea compounds (for example, Nicarak (registered trademark) MX-270 manufactured by Nippon Carbide Industrial Co., Ltd.). Examples of the benzoguanamine compound include benzoguanamine, methylated benzoguanamine and the like. Examples of diamines include ethylenediamine, tetramethylenediamine, hexamethylenediamine, N, N'-diphenylethylenediamine, p-xylylenediamine and the like.

As polyfunctional isocyanate compounds, for example, diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), trimethylhexamethylene diisocyanate (TMDI), xylene diisocyanate (XDI), naphthalene Diisocyanate (NDI), trimethylolpropane (TMP) adduct TDI, TMP adduct HDI, TMP adduct IPDI, TMP adduct XDI, etc. may be mentioned.

As a polyfunctional epoxy compound, N, N, N ', N'- tetraglycidyl metaxylene diamine, a 1, 3- bis (N, N- diglycidyl aminomethyl) cyclohexane etc. are mentioned, for example.

Examples of polyfunctional metal compounds include aluminum chelate compounds, titanium chelate compounds, trimethoxyaluminum and the like. Examples of the aluminum chelate compound include aluminum trisacetylacetonate, aluminum ethylacetoacetate / diisopropylate and the like. Examples of titanium chelate compounds include titanium tetraacetylacetonate, titanium acetylacetonate, titanium octylene glycolate, tetraisopropoxy titanium, tetramethoxy titanium and the like.

In the surface layer, the content of the crosslinking agent (D) reduces the difference in peel force before and after heating, and further makes it difficult to transfer the components of the surface layer to the article, the modified acrylic resin (A) and the modified resin It is preferable that it is 3 mass parts or more with respect to a total of 100 mass parts of resin (B) different from acrylic resin (A), It is more preferable that it is 4 mass parts or more, It is 5 mass parts or more Is more preferred. Moreover, it is preferable that it is 30 mass parts or less with respect to a total of 100 mass parts of resin (B) different from modified acrylic resin (A) and modified acrylic resin (A) from the same viewpoint, and 20 mass It is more preferably part or less, further preferably 10 parts by mass or less.

<Other ingredients>
[Additive]
Each of the surface layer and the base material layer may further contain at least one additive as necessary, in addition to the resin component as the main component. Examples of the additive include an acid catalyst, an antioxidant, a chlorine absorber, a stabilizer such as an ultraviolet absorber, a lubricant, a plasticizer, a flame retardant, an antistatic agent, a colorant, and an antiblocking agent. . Such additives may be added to the base layer and the surface layer within the range not impairing the effects of the present invention. At least one additive may be contained only in any of the base layer and the surface layer, or may be contained in all layers of the base layer and the surface layer. The base layer and the surface layer may also contain the same or different additives.

The “acid catalyst” can improve the compactness of the coating film by the crosslinking reaction, and can suppress the precipitation of the oligomer. As an acid catalyst for this crosslinking reaction, for example, an acidic catalyst such as paratoluenesulfonic acid, methyl paratoluenesulfonate, ethyl paratoluenesulfonate, n-butyl paratoluenesulfonate, benzenesulfonic acid, sulfonic acid, methanesulfonic acid and the like is preferably used. It can be used. An acid catalyst can be used 1 type or in combination of 2 or more types. The amount of the acid catalyst used is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and more preferably 0.5 parts by mass with respect to 100 parts by mass of the resin component constituting the surface layer. It is more preferable that it is more than. The amount of the acid catalyst used is preferably 3 parts by mass or less, more preferably 2 parts by mass or less, and 1.5 parts by mass or less with respect to 100 parts by mass of the resin component constituting the surface layer. It is further preferred that

The antioxidant is not particularly limited, and, for example, 2,6-di-tert-butyl-p-cresol (general name: BHT), phenol type, hindered amine type, phosphite type, lactone type and tocopherol type Antioxidants are mentioned. Specifically, dibutyl hydroxytoluene, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris ( Examples include 3,5-di-t-butyl-4hydroxy) benzene and tris (2,4-di-t-butylphenyl) phosphite.

The "chlorine absorber" is not particularly limited, and examples thereof include metal soaps such as calcium stearate.

The "UV absorber" is not particularly limited, and examples thereof include benzotriazole (such as Tinuvin 328 manufactured by BASF), benzophenone (such as Cysorb UV-531 manufactured by Cytec), hydroxybenzoate (such as UV-CHEK-AM-340 manufactured by Ferro), etc. Can be mentioned.

The "plasticizer" is not particularly limited, and examples thereof include citric acid ester, dibutyl phthalate, polyethylene glycols, propylene glycols, glycerin and the like.

The "flame retardant" is not particularly limited, and examples thereof include halogen compounds, aluminum hydroxide, magnesium hydroxide, phosphate, borate and antimony oxide.

The "antistatic agent" is not particularly limited, and examples thereof include glycerin monoester (glycerin monostearate and the like), and an ethoxylated secondary amine.

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 the effect as a nucleating agent is not exhibited. Examples of antiblocking agents include silica, alumina, (synthetic) zeolite, calcium carbonate, kaolin, talc, mica, zinc oxide, magnesium oxide, quartz, magnesium carbonate, palladium carbonate, palladium sulfate, titanium dioxide, etc., and polystyrene particles , Polyacrylic particles, polymethyl methacrylate (PMMA) particles, crosslinked polyethylene particles, polyester particles, polyamide particles, polycarbonate particles, polycarbonate particles, polyether particles, polyether sulfone particles, polyetherimide, polyphenylene sulfide, polyether ether ketone, polyamide Imide particles, (crosslinked) melamine resin particles, benzoguanamine resin particles, urea resin particles, amino resin particles, furan resin particles, epoxy resin particles, phenol resin particles, unsaturated polyester Ether resin particles, a vinyl ester resin particles, diallyl phthalate resin particles, polyimide resin particles, the organic particles such as fatty acid amides particles and fatty acid glycerol ester compound particles and the like. The antiblocking agent is preferably particles having a particle size of 0.1 μm to 10 μm, and PMMA particles and silica particles are more preferable because they are excellent in blocking resistance and slipperiness. For example, when such particles are contained in the above-mentioned base material layer, the slipperiness of front and back of the base material layer can be improved, and blocking can be suppressed.

Moreover, in the first embodiment, it is preferable that the surface layer does not substantially contain a silicone compound so as not to adversely affect the electrical parts and the like. The term "substantially free of silicone compound" means that the amount of silicone compound is preferably 500 μg / g or less, more preferably 100 μg / g or less.

The thickness of the surface layer is preferably 0.01 μm or more, more preferably 0.05 μm or more, and particularly preferably 0.1 μm or more from the viewpoint of easily enhancing the releasability. The thickness of the surface layer is preferably 3 μm or less, more preferably 1.5 μm or less, and more preferably 1 μm or less, from the viewpoint of transfer of the polymer component to the base layer. The thickness of the surface layer is observed using a transmission electron microscope (TEM) (for example, “HT7700 type” manufactured by Hitachi High-Technologies Corporation), and specifically measured by the method described in the examples.

[Method of producing surface layer]
The surface layer can be formed by laminating a resin component that forms the surface layer on the base material layer. Preferred embodiments of the method for producing the surface layer include a modified acrylic resin (A), a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D), and, if necessary, other components. A coating solution containing at least one solvent and the like on the base material layer, the resin (A) and the resin (B) are crosslinked, and obtained by the coating It is formed by removing the solvent from the coated layer.

The solvent is not particularly limited as long as components other than the solvent in the coating liquid can be dissolved and / or uniformly dispersed. Examples of the solvent include organic solvents of ketone / ester type such as methyl ethyl ketone (MEK) and ethyl acetate, and organic solvents such as aliphatic hydrocarbon such as n-heptane and methyl cyclohexane. The boiling point of the solvent is preferably 10 to 150 ° C., more preferably 20 to 120 ° C., from the viewpoint of easily improving the handling property of the coating liquid and the production efficiency of the peelable film. Only one type of solvent may be used, or two or more types may be mixed and used.

Concentration of components other than the solvent in the coating liquid (so-called concentration of solid component remaining in the surface layer after removing the solvent, for example, modified acrylic resin (A), modified acrylic resin (A) The total concentration of different resins (B), crosslinking agent (D), and other components optionally blended is not limited, but from the viewpoint of coating liquid stability and coating suitability. The amount is preferably 1 to 24% by mass, more preferably 1 to 19% by mass, still more preferably 2 to 14% by mass, and 2 to 10% by mass with respect to the total amount of the coating liquid. Particularly preferred. The coating method is not particularly limited. For example, a method using a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a microgravure coater, a rod blade coater, a lip coater, a die coater, a curtain coater, or a printing machine is mentioned. Be

As a method of crosslinking the resin (A) and the resin (B) in the coating layer, heating the coating layer in the presence of the crosslinking agent (D) may be mentioned. For example, a method of applying hot air to the coating layer for heating, and heating the coating layer with an electromagnetic wave such as infrared rays may be mentioned.
The method for removing the solvent from the coating layer is not particularly limited as long as the solvent can be volatilized. Note that removing the solvent does not only mean completely removing the solvent, but also includes removing the solvent to such an extent that a layer is formed. Examples of the method for removing the solvent include a method of applying a wind to the coated layer to dry it, a method of drying the coated layer by heating, and the like.
The drying temperature by heating or the heating temperature is preferably 70 to 170 ° C., and more preferably 90 to 150 ° C., from the viewpoint of easily achieving both solvent removal and acceleration of the crosslinking reaction. The drying time or heating time is preferably 10 to 300 seconds, more preferably 15 to 90 seconds, and still more preferably 20 to 50 seconds.

Although the peelable film of the first embodiment may or may not be stretched, it is preferable that the surface layer be non-stretched from the viewpoint of easily obtaining good light peelability.

[Roughening of Releasable Film Surface]
In the first embodiment, the surface of the peelable film may be provided with a fine surface roughness for improving the winding suitability, as long as there is no hindrance to the bonding in the case of using as a peelable film. An embossing method, an etching method, etc. and various well-known roughening methods can be employ | adopted as a method of providing fine unevenness | corrugation on the peelable film surface.

The peelable film of the first embodiment can be appropriately set depending on the use application from a very light (very low) T-peel peel force to a moderately light (moderately low) peel force. From the viewpoint of easily enhancing the adhesion of the peelable film to the adherend, it is preferably 0.01 N / 25 mm or more, more preferably 0.02 N / 25 mm or more, and still more preferably 0.05 N / 25 mm or more. The T-peel peeling force is preferably 2.00 N / 25 mm or less, more preferably 1.50 N / 25 mm or less, and more preferably 1.00 N / 25 mm or less, from the viewpoint of easily increasing the peelability. More preferably, it is 0.70 N / 25 mm or less, more preferably 0.50 N / 25 mm or less, more preferably 0.40 N / 25 mm or less, more preferably 0.30 N / 25 mm or less, more preferably Is 0.25 N / 25 mm or less, more preferably 0.22 N / 25 mm or less, and still more preferably 0.20 N / 25 mm or less. The T-peel peeling force of the peelable film is measured by the following method.

[T-peel peeling force]
In a normal temperature (25 ° C.) environment, 2 kg of polyester adhesive tape (Nitto Denko Corporation NO. 31 B tape, acrylic adhesive) 50 mm wide × 200 mm long on the surface of the peelable film on the surface layer side Apply by reciprocating the roller twice. The obtained film is heat-treated at 160 ° C. for 90 seconds, and then allowed to stand for 20 hours under an environment of 70 ° C. and 50% humidity. Next, in a normal temperature environment (25 ° C.), a sample cut out from the obtained film to a width of 25 mm is used as a measurement sample and a tensile tester (for example, a universal tensile tester Technograph TGI-1kN manufactured by Minebea Co., Ltd.) T-peel peeling is performed at a speed of 1000 mm / min, and the peeling force at that time is measured. The value measured in this manner is referred to as T-peel peeling force (T-peel peeling force before heating).

Further, it is preferable that the post-heating T-peel peeling force of the peelable film of the first embodiment has a small difference from the pre-heating T-peel peeling force ((T-peel peeling force after heating))-(before heating) The value of T-peel peeling force) is preferably -0.20 to +0.20, more preferably -0.10 to +0.10, still more preferably -0.08 to +0.05, and -0.04 to +0.02 is particularly preferred. The post-heating T-peel peeling force of the peelable film is measured by the following method.

[T-peel peeling force after heating]
In a normal temperature (25 ° C) environment, a 2 kg roller with a 50 mm wide and 200 mm long polyester adhesive tape (Nitto Denko Corporation NO. 31 B tape, acrylic adhesive) on the film surface of the peelable film on the surface layer side Paste by making 2 reciprocations to obtain a patch before treatment. Next, the patch is heat-treated at 160 ° C. for 90 seconds. In the heat treatment, a hot air drier is used. Here, the heat treatment at 160 ° C. for 90 seconds means that the patch was placed in a hot air dryer set at 160 ° C. Next, a weight is placed on the patch so as to give a load of 5 KPa, and the patch is allowed to stand at 70 ° C. under an environment of 50% humidity for 20 hours. Next, in a normal temperature environment (25 ° C.), a sample cut out from the obtained film to a width of 25 mm is used as a measurement sample and a tensile tester (for example, a universal tensile tester Technograph TGI-1kN manufactured by Minebea Co., Ltd.) T-peel peeling is performed at a speed of 1000 mm / min, and the peeling force at that time is measured. The value thus measured is taken as the T-peel peeling force after heating.

[Thickness of Peelable Film]
The thickness of the peelable film is preferably 18 μm or more, more preferably 20 μm or more from the viewpoint of the handleability as a peelable film. The thickness of the peelable film is preferably 100 μm or less, more preferably 50 μm or less, from the viewpoint of handleability as a peelable film. The thickness of the peelable film of the first embodiment is measured using a micrometer (JIS B-7502) according to JIS C-2151.

The peelable film of the first embodiment is excellent as a peelable film because it has good peelability and maintains the above-mentioned good peelability even after being heat-treated. The peelable film of the first embodiment can be widely used in the industrial field, medical field, etc. For example, a peelable film used for a surface protection film, an adhesive tape, etc., a release liner or separator film, at the time of producing a semiconductor product It is suitably used as a separator film of a process (dicing, die bonding, back grinding) tape used, a carrier for forming an unfired sheet at the time of producing a ceramic capacitor, a carrier at the time of producing a composite material, a separator film of a protective material and the like. In addition, the said unbaked sheet | seat is also called a green sheet, and the said carrier is also called process film. The peelable film of the first embodiment is a tape or sheet; resin members such as electric devices, electronic devices, wearable devices, medical devices and building materials; intermediate members manufactured in the process of manufacturing the semiconductor product; various electric parts (Hard disk, motor, connector, switch, etc.); object in the case of using as the above-mentioned carrier; dry film resist; When the adherend described above has an adhesive layer (for example, a solvent-based, emulsion-based or hot-melt pressure-sensitive adhesive layer), the surface layer of the peelable film of the first embodiment and the adhesive The peelable film of the first embodiment may be used by being attached to an adherend so that the agent layer is laminated. The method of affixing the peelable film of the first embodiment to an object is not particularly limited. The peelable film of the first embodiment may be appropriately cut and attached to the object according to, for example, the area to which it is attached, or the peelable film of the first embodiment may also be attached. The objects to be attached may also be bonded by roll-to-roll if they are each wound in a roll.

Second Embodiment
The peelable film according to the second embodiment is a laminated film having a base material layer and a surface layer on at least one side of the base material layer.

[Base material layer]
In the second embodiment, the description on the base material layer is the same as the description in the first embodiment.

[Surface layer]
The peelable film of the second embodiment has a surface layer on a base material layer. The surface layer is a layer for imparting releasability to the releasable film. The surface layer may be formed on the base material layer through each layer such as an adhesive layer between the base layer and the base layer, but the main surface of the surface layer is in contact with the main surface of the base material layer. Preferably, a surface layer is formed.

The peelable film according to the second embodiment has a carbon content ratio M _C5 (atomic%) to the total element content present at a depth of 5 nm vertically from the outermost surface in the surface layer to the base material layer ) Is 98 or more (more specifically, 98.0 or more) (i.e., 98 ≦ M _C5 , and further 98.0 ≦ M _C5 ). The M _C5 falls below 98atomic% (i.e., M _C5 <98) if it is, becomes the alkyl chain is not segregated on the outermost surface side of the surface layer, there is a possibility that not be possible to impart sufficient releasability. The upper limit of M _C5, but are not limited to, (more specifically, an M _C5 ≦ 99.0, M _C5 99 or less, more 99.0 or less) M _C5 ≦ 99 are preferable. As a means to adjust _MC5 , adjustment of the ratio of the modified acrylic resin (A) component mentioned later, adjustment of the thickness of a layer, etc. are mentioned.

<Relationship between the M _C5 and M _C40>
The ratio of the content of carbon to the total elemental content present at a depth of 5 nm vertically from the outermost surface in the surface layer toward the base material layer is M _C5 (atomic%), and the outermost surface in the surface layer Assuming that the content ratio of carbon to the total element content present at a depth of 40 nm vertically toward the base material layer is M _C40 (atomic%), the relationship between M _C5 and M _C40 is 1.01 ≦ It is preferable that M _C5 / M _C40 ≦ 1.10. When M _C5 / M _C40 is 1.01 ≦ M _C5 / M _C40 ≦ 1.10, it indicates that the alkyl chain is segregated on the outermost surface side of the surface layer, and sufficient peelability can be obtained.

In the second embodiment, the relationship between the M _C5 and M _C40 is preferably _{_{1.03 ≦ M C5 / M C40 ≦}} 1.10, more preferably _{_{1.04 ≦ M C5 / M C40 ≦}} 1.10, It is further preferable that 1.04 ≦ M _C5 / M _C40 ≦ 1.09. Each preferred embodiment of the relationship between the M _C5 and M _C40 are those found from the viewpoint of good release properties.

Here, the technical significance of M _C5 / M _C40 will be described. M _C5 / M _C40 indicates the degree (degree) of segregation of the alkyl chain on the outermost surface. A large M _C5 / M _C40 value indicates that the alkyl chain is more segregated with respect to the outermost surface. Here, in the surface layer, when 1.01 ≦ M _C5 / M _C40 ≦ 1. 10, the alkyl chain is segregated on the outermost surface of the surface layer, and therefore groups or components other than the alkyl chain are the base material layer or It is believed to interact with the substrate layer and other layers adjacent thereto. Due to such a mechanism, the peelable film of the second embodiment has an effect of good peelability by the alkyl chain and an object attached to the surface layer after being exposed to high temperature. It is speculated that it has the effect of maintaining good releasability.

As a means to adjust the value of M _C5 , M _C40 , and M _C5 / M _C40 , respectively, the kind and content of the alkyl acrylate component in the modified acrylic resin (A) described later; resin (B) described later And their contents; and the like. As an example, in the film according to the second embodiment, when the surface layer contains a modified acrylic resin (A) described later and a resin (B) described later, and the resin (B) is a polyester resin, the resin As the content of (B) increases, the _MC5 value tends to decrease, and the _MC5 / _MC40 value tends to increase.

In the present invention, and herein, the value of M _C5 and M _C40 is measured by the technique described in each embodiment, the value of M _C5 / M _C40 is calculated from the measured values.

The carbon content ratio M _C5 (atomic%) to the total element content present at a depth of 5 nm vertically from the outermost surface in the surface layer of the peelable film toward the substrate layer is the surface by Ar ion sputtering It is a value measured by conducting XPS analysis while shaving the layer from the outermost surface side. Measurement mode: Measurement mode: Monochromator, X-ray source: Al, measurement area: 500 μmφ, measurement element: carbon (C) using an X-ray electron spectroscopy (XPS) measuring instrument ESCA LAB 250 (manufactured by Thermo VG scientific) Do. The conditions of sputtering are: irradiation ion: argon (Ar), current value: 2.5 (μA), voltage: 120 (V), sputtering rate: 0.1 (nm / sec).

The content ratio of carbon to total element content at the position of the vertical depth 40nm towards the base layer from the outermost surface of the surface layer of the peelable film M _C40 (atomic%), similar to M _C5, This is a value measured by carrying out XPS analysis while shaving the surface layer from the outermost surface side by Ar ion sputtering. Also, measurement conditions M _C40 (measuring instrument, measurement mode, X-rays source, the measurement area, the measurement elements and the like) and sputtering conditions (irradiation ion current, voltage, sputtering rate, etc.) for the measurement of the M _C5 The same as in the condition.

The main component forming the surface layer is a resin component. Further, the resin component contains a modified acrylic resin (A) having an alkyl component and a crosslinkable functional group, a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D). Is preferred. That is, the surface layer comprises a modified acrylic resin (A) having an alkyl component and a crosslinkable functional group as a resin component, a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D). It is preferable to be comprised by the hardened | cured material of the resin composition to contain. In the peelable film of the second embodiment, the main component that forms the surface layer is a resin component, and the resin component is an alkyl component and a modified acrylic resin (A) having a crosslinkable functional group, and the modified resin. When the resin (B) different from the acrylic resin (A) and the cross-linking agent (D) are included, a peelable film having excellent peelability and light resistance is easily obtained while having good peelability that the peel force is light. . Hereinafter, the modified acrylic resin (A), the resin (B) different from the modified acrylic resin (A), and the crosslinking agent (D) will be described in detail.

<Modified acrylic resin (A)>
The modified acrylic resin (A) having an alkyl component and a crosslinkable functional group is a resin having an alkyl group as a side chain with respect to the main chain acrylic resin. The modified acrylic resin (A) contains at least a structural unit (formed by a monomer a described below) represented by the general formula (I).

The description of the structural unit represented by the general formula (I) is the same as the description in the first embodiment.

Moreover, the description of the crosslinkable functional group (reactive functional group) in the modified acrylic resin (A) is the same as the description in the first embodiment.

[Monomer a]
Examples of the monomer a include (meth) acrylic esters in which the ester moiety is a long-chain alkyl group having 10 to 18 carbon atoms, and specific compounds are the same as those exemplified in the first embodiment. is there.

In the second embodiment, the content ratio of the structural unit derived from the monomer a in the modified acrylic resin (A) is a modified acrylic resin (A) from the viewpoint of lightening the peeling force and further improving the heat resistance. Preferably, about 50 to 99.99 parts by mass, more preferably about 70 to 99.9 parts by mass, still more preferably about 85 to 99.8 parts by mass, based on 100 parts by mass of the total of structural units contained in Preferably, it is 85 to 99.5 parts by mass. As the monomer a, only one type may be used, or two or more types may be mixed and used.

[Monomer b]
The monomer b is a monomer having a carbon-carbon unsaturated double bond and a crosslinkable functional group in one molecule. Since the monomer b has a crosslinkable functional group, in the second embodiment, a resin (B) different from the modified acrylic resin (A) via a crosslinking agent (D) described later (B) And the like to reduce peeling force and to further improve heat resistance.

In the second embodiment, the crosslinkable functional group (reactive functional group) of the monomer b may be, for example, a carboxyl group, an isocyano group, an epoxy group, an N-methylol group, N as in the first embodiment. An alkoxymethyl group, a hydroxy group, an amino group, a thiol group, a hydrolyzable silyl group, and the like, and the description of the crosslinkable functional group is the same as the description in the first embodiment.

In the second embodiment, when the modified acrylic resin (A) contains a constitutional unit derived from the monomer b, the content ratio of the constitutional unit derived from the monomer b in the modified acrylic resin (A) is From the viewpoint of lightening the peeling force and further improving the heat resistance, it is preferable that the total of structural units contained in the modified acrylic resin (A) is about 0.01 to 20 parts by mass, It is more preferably about 0.1 to 10 parts by mass, further preferably about 0.2 to 5 parts by mass, still more preferably about 0.5 to 3 parts by mass, and 0.8 to 1.5 It is particularly preferred that the amount is about parts by mass. When the modified acrylic resin (A) contains not only a structural unit derived from the monomer a but also a structural unit derived from the monomer b, the primary structure may be a random copolymer, It may be a block copolymer.

[Monomer c]
The monomer c is an acrylic monomer having a carbon-carbon unsaturated double bond and an alkyl group having 1 to 9 or 19 or more carbon atoms in one molecule. In the second embodiment, the monomer c can be used, for example, to adjust the concentration of the alkyl group contained in the surface layer, and as a result, the peeling force can be reduced and the heat resistance can be further improved. it can.

As the monomer c, (meth) acrylic acid derivatives are preferably mentioned. As the (meth) acrylic acid derivative, a monomer from which the constituent unit represented by the general formula (III) is derived is preferable. In the second embodiment, the description of the constituent unit represented by the general formula (III) is the same as the description in the first embodiment.

The specific example of the monomer c is the same as the illustration in the first embodiment, and as the monomer c, only one type may be used, or two or more types may be mixed and used.

In the second embodiment, when the modified acrylic resin (A) contains a constitutional unit derived from the monomer c, the content ratio of the constitutional unit derived from the monomer c in the modified acrylic resin (A) is From the viewpoint of lightening the peeling force and further improving the heat resistance, it is preferable that the total of structural units contained in the modified acrylic resin (A) is about 0.01 to 20 parts by mass, More preferably, it is about 0.1 to 10 parts by mass.

Specific examples of the monomer d include the same monomers as in the first embodiment, and only one monomer d may be used, or two or more monomers may be mixed and used. May be In the second embodiment, the monomer d can be used, for example, to adjust the concentration of various functional groups contained in the surface layer, to lighten the peel force of the peelable film, and to further improve the heat resistance. It can be improved.

In the second embodiment, when the modified acrylic resin (A) contains a constitutional unit derived from the monomer d, the content ratio of the constitutional unit derived from the monomer d in the modified acrylic resin (A) is From the viewpoint of lightening the peeling force and further improving the heat resistance, it is preferable that the total of structural units contained in the modified acrylic resin (A) is about 0.01 to 20 parts by mass, More preferably, it is about 0.1 to 10 parts by mass.

In the second embodiment, the weight average molecular weight of the modified acrylic resin (A) is preferably 5 × 10 ⁴ to 15 × 10 ⁴ from the viewpoint of lightening the peeling force and further improving the heat resistance. Preferably it is 6 × 10 ⁴ to 14 × 10 ⁴ , more preferably 8 × 10 ⁴ to 12 × 10 ⁴ .

In the second embodiment, the content of the modified acrylic resin (A) in the surface layer is not particularly limited, but from the viewpoint of lightening the peeling force and further improving the heat resistance, the resin constituting the surface layer The total amount of (A) and the resin (B) is preferably 100 parts by mass, more than 50 parts by mass is preferable, 52 parts by mass or more is more preferable, and 55 parts by mass or more is more preferable. In addition, the content of the modified acrylic resin (A) in the surface layer is preferably 98 parts by mass or less with respect to a total of 100 parts by mass of the resin (A) and the resin (B) constituting the surface layer. It is more preferably 97 parts by mass or less, still more preferably 90 parts by mass or less, still more preferably 80 parts by mass or less, particularly preferably 70 parts by mass or less, and 60 parts by mass or less It is particularly preferred that there be. Here, in the second embodiment, the fact that the content of the resin (A) exceeds 50 parts by mass with respect to the total of 100 parts by mass of the resin (A) and the resin (B) is the resin (A). parts by mass M _a of), and the parts by weight of the resin (B) in the case of the M _B, 1 <is synonymous with an M _a / M _B. Similarly, it the content of the resin (A) is 52 parts by mass or more is 1.083 ≦ M _A / M _B, it is 55 parts by mass or more 1.222 ≦ M _A / Being M _B and being 97 parts by mass or less are synonymous with M _A / M _B ≦ 32.333, respectively. When the content of the resin (A) exceeds 50 parts by mass based on 100 parts by mass of the total of the resin (A) and the resin (B), the peeling force can be reduced and the heat resistance can be further improved. The difference in peel force after heating and before heating is very small, and the residual adhesion rate is also excellent.

In the second embodiment, the content (%) of the modified acrylic resin (A) in the surface layer is, for example, 50% by mass from the viewpoint of lightening the peeling force and further improving the heat resistance. Above, 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, etc. may be mentioned.

As a method of obtaining a modified acrylic resin (A), the same method as the description in the first embodiment can be adopted.

<Resin (B)>
In the second embodiment, the resin component for forming the surface layer preferably contains a resin (B) different from the modified acrylic resin (A) together with the modified acrylic resin (A).

In the second embodiment, by including the resin (B) in the surface layer, the alkyl group of the modified acrylic resin (A) is obtained by utilizing the difference in compatibility with the modified acrylic resin (A). It is easy to segregate on the surface, and as a result, the peeling force is lightened and the heat resistance is further improved.

In the second embodiment, the resin (B) is not particularly limited, but preferably includes at least one selected from the group consisting of a polyester resin and an acrylic resin. Among them, polyester resin is more preferable as the resin (B). The description of the polyester resin and the acrylic resin is the same as the description in the first embodiment.

The resin (B) different from the modified acrylic resin (A) preferably has a reactive functional group in order to react with a crosslinking agent (D) described later. In particular, the reactive functional group is preferably at least one selected from the group consisting of a carboxyl group and a hydroxy group. In the second embodiment, when the resin (B) has a hydroxy group, the hydroxyl value of the resin (B) is preferably 5 to 500 mg KOH / g, more preferably 10 to 300 mg KOH / g. 10 to 100 mg KOH / g is more preferable, and 10 to 40 mg KOH / g is particularly preferable. When the hydroxyl value of the resin (B) is in each of the above-mentioned preferable ranges, the density of the crosslinked network structure by the crosslinking agent (D) described later is appropriate, and the peeling power is further reduced. In particular, in the case where the resin (B) is a polyester resin having a hydroxyl value within each of the preferred ranges, the above tendency is strong.

The number average molecular weight of the resin (B) is the same as in the first embodiment.

In the second embodiment, the resin (B) in the surface layer preferably has a glass transition temperature (Tg) of 55 ° C. or higher. Moreover, as for the said glass transition temperature, 58 degreeC or more is more preferable. When the glass transition temperature of the resin (B) in the surface layer is within each of the above preferable ranges, the peeling power is further reduced and the heat resistance is improved. In particular, when the resin (B) is a polyester resin having a glass transition temperature in each of the preferable ranges, the above tendency is strong. 100 degreeC or less is preferable, as for the glass transition temperature of the said resin (B) in a surface layer, 90 degrees C or less is more preferable, 80 degrees C or less is further more preferable, and 70 degrees C or less is especially preferable.

In the second embodiment, the content of the resin (B) in the surface layer is not limited, but from the viewpoint of lightening the peeling force and further improving the heat resistance, the resin (A) constituting the surface layer and The total amount of the resin (B) is 100 parts by mass, preferably 2 parts by mass or more, more preferably 3 parts by mass or more, still more preferably 10 parts by mass or more, and 20 parts by mass or more It is even more preferable, particularly preferably 30 parts by mass or more, and particularly preferably 40 parts by mass or more. From the same point of view, the total amount of the resin (A) and the resin (B) constituting the surface layer is 100 parts by mass, preferably less than 50 parts by mass, more preferably 48 parts by mass or less, and 45 parts by mass or less Is more preferred. Here, that the content of the resin (B) is less than 50 parts by mass based on 100 parts by mass of the total of the resin (A) and the resin (B) means that the mass part of the resin (B) is M _A , and in a case where the parts by weight of the resin (B) was M _B, 1 <it is synonymous with an M _a / M _B. Similarly, it the content of the resin (B) is not more than 48 parts by mass is 1.083 ≦ M _A / M _B, is not more than 45 parts by 1.222 ≦ M _A / Being M 3 _B and being 3 parts by mass or more are synonymous with M _A / M _B ≦ 32.333, respectively. When the content of the resin (B) is less than 50 parts by mass based on 100 parts by mass of the total of the resin (A) and the resin (B), the peeling power can be reduced and the heat resistance can be further improved. The difference in peel force after heating and before heating is very small, and the residual adhesion rate is also excellent.

<Crosslinking agent (D)>
In the second embodiment, the resin component that forms the surface layer preferably contains a crosslinking agent (D) together with the modified acrylic resin (A) and the resin (B). The crosslinking agent (D) has a function of crosslinking the modified acrylic resins (A), the resins (B), or the modified acrylic resin (A) and the resin (B). The crosslinking agent (D) can be used singly or in combination of two or more.

In the second embodiment, the crosslinking agent (D) is not limited, for example, polyfunctional amino compounds, isocyanate compounds (including monoisocyanate, diisocyanate, polyfunctional isocyanate etc.), polyfunctional epoxy compounds, polyfunctional compounds, etc. It is preferably a functional metal compound or a dialdehyde. In the second embodiment, the crosslinking agent (D) is preferably a polyfunctional amino compound, more preferably a melamine compound. The melamine compound is particularly preferably a melamine compound having a structure in which all hydrogen atoms of the amino group are substituted with at least one of an alkoxyalkyl group and an alkanol group. It can be said that the above-mentioned particularly preferable melamine compound has at least one selected from the group consisting of an alkoxyalkyl group and an alkanol group as a substituent of the amino group. In addition, the above-mentioned particularly preferred melamine compound has a structural unit in which three amino groups are bonded to a triazine ring, and in the second embodiment, a total of six substituents bonded to three amino groups are And at least one selected from the group consisting of an alkoxyalkyl group and an alkanol group, and it can be said that it does not have any other substituent such as a hydrogen atom.

More specifically, the above-mentioned particularly preferred melamine compound can be represented by the above general formula (IV). The description of the melamine compound represented by the general formula (IV) is the same as the description in the first embodiment.

In the second embodiment, the melamine compound particularly preferred from the viewpoint of lightening the peeling force and further improving the heat resistance is at least one of six substituents R in the general formula (IV). It is preferable that it is an alkoxy alkyl group, It is more preferable that 3 or more are alkoxy alkyl groups, It is especially preferable that all 6 are alkoxy alkyl groups. In the general formula (IV), among the six substituents R, the number of alkanol groups is preferably 5 or less, more preferably 3 or less, and still more preferably 0. That is, as the melamine compound, all of the substituents R of the amino group having three bonds per constitutional unit (substituents R of the six amino groups) are either a methoxymethyl group or a methylol group, and The melamine compound in which at least one of the substituents R is a methylol group is a preferred embodiment.

In the particularly preferred melamine compound of the second embodiment, the carbon number of the alkoxyalkyl group is preferably 2 to 5, and more preferably 2. Preferred specific examples of the alkoxyalkyl group include propoxymethyl group, ethoxymethyl group, methoxymethyl group and the like, and among these, methoxymethyl group is particularly preferable. The carbon number of the alkanol group is preferably 1 to 3, and more preferably 1. Specific preferred examples of the alkanol group include propanol group (3-hydroxypropyl group), ethylol group (2-hydroxyethyl group), methylol group (hydroxymethyl group) and the like, and among these, methylol group is particularly preferable.

The average n amount number of the melamine compound is the same as the description in the first embodiment.

In the second embodiment, the melamine compound is particularly preferably a compound represented by the general formula (V) from the viewpoint of reducing the peeling force and further improving the heat resistance. The description of the melamine compound represented by the general formula (V) is the same as the description in the first embodiment.

In the second embodiment, the resin component forming the surface layer may contain another crosslinking agent different from the above-mentioned melamine compound particularly preferred as the crosslinking agent (D). The crosslinking agent contained in the resin component is preferably only the melamine compound particularly preferred as the crosslinking agent (D).

Other crosslinking agents include, but are not limited to, for example, polyfunctional amino compounds different from the above-mentioned particularly preferred melamine compounds, isocyanate compounds (including monoisocyanate, diisocyanate, polyfunctional isocyanate etc.), polyfunctional Epoxy compounds, polyfunctional metal compounds or dialdehydes may be mentioned.

Examples of the polyfunctional amino compound different from the above-mentioned particularly preferable melamine compound include urea compounds, benzoguanamine compounds, diamines and the like. Specific examples of these polyfunctional amino compounds are the same as the specific examples described in the first embodiment.

In the surface layer of the second embodiment, the content of the crosslinking agent (D) makes the peeling force light and further improves the heat resistance, the modified acrylic resin (A) and the modified acrylic resin (A) It is preferably 3 parts by mass or more, more preferably 4 parts by mass or more, and still more preferably 5 parts by mass or more with respect to a total of 100 parts by mass of the resin (B) different from. Moreover, it is preferable that it is 30 mass parts or less with respect to a total of 100 mass parts of resin (B) different from modified acrylic resin (A) and modified acrylic resin (A) from the same viewpoint, and 20 mass It is more preferably part or less, further preferably 10 parts by mass or less.

<Other ingredients>
[Additive]
In the second embodiment, each of the surface layer and the base material layer may further contain at least one additive as necessary, in addition to the resin component as the main component. The description of the additive is the same as the description in the first embodiment.

Moreover, in the second embodiment, it is preferable that the surface layer does not substantially contain a silicone compound so as not to adversely affect the electrical parts and the like. The term "substantially free of silicone compound" means that the amount of silicone compound is preferably 500 μg / g or less, more preferably 100 μg / g or less.

The thickness of the surface layer of the second embodiment is preferably 0.01 μm or more, more preferably 0.05 μm or more, and still more preferably 0.1 μm or more, from the viewpoint of easily enhancing the releasability. Preferably, it is 0.18 μm. The thickness of the surface layer is preferably 3 μm or less, more preferably 1.5 μm or less, and more preferably 1 μm or less, from the viewpoint of transfer of the polymer component to the base layer. The thickness of the surface layer is observed using the same method as in the first embodiment, and specifically measured by the method described in the examples.

[Method of producing surface layer]
In the second embodiment, as in the first embodiment, the surface layer can be formed by laminating the resin component that forms the surface layer on the base material layer. The preferable aspect of the method of producing the surface layer of the second embodiment is the same as that of the first embodiment.

Further, the releasable film of the second embodiment may or may not be stretched as in the first embodiment, but the surface layer is not stretched from the viewpoint of easily obtaining good light releasability. Is preferred.

[Roughening of Releasable Film Surface]
In the second embodiment, the surface of the peelable film may be provided with a fine surface roughness for improving the winding suitability, as long as there is no hindrance to bonding in the case of using as a peelable film. Various well-known roughening methods can be adopted as a method of providing fine irregularities on the surface of the peelable film, as in the first embodiment.

The peelable film of the second embodiment has a very light T-peel peel force (very low). From the viewpoint of easily enhancing the adhesion of the peelable film to the adherend, the T-peel peel force of the peelable film of the second embodiment is preferably 0.01 N / 25 mm or more, more preferably 0.02 N / 25 mm. Or more, more preferably 0.05 N / 25 mm or more. Further, the T-peel peel force of the peelable film of the second embodiment is preferably 0.40 N / 25 mm or less, more preferably 0.30 N / 25 mm or less from the viewpoint of easily enhancing the peelability. More preferably, it is 0.25 N / 25 mm or less, and particularly preferably 0.22 N / 25 mm or less. The T-peel peeling force of the peelable film is measured by the method described in the first embodiment. In addition, the preferable range of T shape peel force after the heating of the peelable film of 2nd Embodiment mentioned later is the same as each preferable range of the said T shape peel force before the said heating.

Further, it is preferable that the post-heating T-peel peeling force of the peelable film of the second embodiment has a small difference from the pre-heating T-peel peeling force ((T-peel peeling force after heating))-(before heating) The value of T-peel peeling force) is preferably -0.20 to +0.20, more preferably -0.10 to +0.10, still more preferably -0.08 to +0.05, and -0.04 to +0.02 is particularly preferred. The post-heating T-peel peeling force of the peelable film is measured by the method described in the first embodiment.

[Thickness of Peelable Film]
The description of the thickness of the peelable film of the second embodiment is the same as the description of the thickness of the peelable film of the first embodiment.

The peelable film of the second embodiment has excellent peelability and is excellent as a peelable film in order to maintain the above-mentioned good peelability even after being heat-treated. The peelable film of the second embodiment can be widely used in the same applications and methods as described in the first embodiment, such as in the industrial field and the medical field.

Hereinafter, the present invention will be described in detail by way of Examples and Comparative Examples. However, the present invention is not limited to the examples. The following Examples 1A to 15A are specific examples of the first embodiment, and Examples 1B to 4B are specific examples of the second embodiment. In addition, unless otherwise indicated, a part and% show a "mass part" and "mass%", respectively.

[Measurement method and evaluation method]
Various measurement methods and evaluation methods in the example and the comparative example are as follows.

[Thickness of surface layer]
After cutting out the sample, the surface of the sample was coated with Os and embedded in a resin. Next, after trimming / surfacing and preparation of ultrathin sections with an ultramicrotome equipped with a diamond knife, transmission electron microscope (TEM) observation was performed.
Sectioning device: Ultra Microtome (LEICA EM UC7 manufactured by Leica Co., Ltd.)
Knife; ULTRADRY observation device manufactured by DIATOME: TEM (HT7700 type manufactured by Hitachi High-Technologies Corporation)
Acceleration voltage: 100kV
Photo magnification: × 300,000 times

[Thickness of Base Layer and Releasable Film]
The thickness of the peelable film and the base material layer was measured according to JIS C-2151 using a micrometer (JIS B-7502).

[X-ray electron spectroscopy (XPS) analysis]
The XPS analysis is carried out while shaving the surface layer from the outermost surface side by Ar ion sputtering, and the position relative to the total element content present at a depth of 5 nm vertically from the surface layer of the peelable film toward the base material layer The ratio M _c5 (atomic%) of the carbon content present in was measured under the following conditions.
Measuring instrument: X-ray electron spectroscopy (XPS) measuring instrument ESCA LAB 250 (made by Thermo VG scientific)
Measurement mode: Monochromator, X-ray source: Al, measurement area: 500 μmφ
Measuring element: carbon (C)
The conditions for sputtering were as follows.
Irradiated ion: Argon (Ar), Current value: 2.5 (μA), Voltage: 120 (V), Sputtering rate: 0.1 (nm / sec)

[XPS depth direction analysis]
The XPS analysis is carried out while shaving the surface layer from the outermost surface side by Ar ion sputtering, and the content of carbon with respect to the total element content existing at a depth of 40 nm vertically from the outermost surface in the surface layer to the base material layer The quantitative ratio _MC40 (atomic%) was measured. The measurement conditions of XPS are the same as the measurement conditions of the above-mentioned _MC5 .

[T-peel peeling force]
A 50 mm wide × 200 mm long polyester adhesive tape (Nitto Denko Corporation NO. 31 B tape, acrylic adhesive) is attached to the surface of the film on the surface layer side of the peelable film by reciprocating a 2 kg roller twice. Obtained the pre-treatment patch.
Next, a weight was placed on the patch so as to give a load of 5 KPa, and left to stand at 70 ° C. under an environment of 50% humidity for 20 hours.
Next, under the environment of room temperature, each obtained treated patch was cut into a 25 mm width and used as a measurement sample, using a peel tester (Menpea Co., Ltd. universal tensile tester Technograph TGI-1kN). And a T-peel peeling test was conducted at a speed of 1000 mm / min, and the peeling force at that time was measured. The measurement was performed three times, and the average value was used as the T-peel peeling force (T-peel peeling force before heating) of each peelable film. The results are shown in Table 1.

[T-peel peeling force after heating]
A 50 mm wide × 200 mm long polyester adhesive tape (Nitto Denko Corporation NO. 31 B tape, acrylic adhesive) is attached to the surface of the film on the surface layer side of the peelable film by reciprocating a 2 kg roller twice. Obtained the pre-treatment patch.
Next, the patch was heat-treated at 160 ° C. for 90 seconds. In the heat treatment, a hot air drier was used. Here, the heat treatment at 160 ° C. for 90 seconds means that the patch was placed in a hot air dryer set at 160 ° C.
Next, a weight was placed on the patch so as to give a load of 5 KPa, and left to stand at 70 ° C. under an environment of 50% humidity for 20 hours. Next, T-peel peeling force after heating was obtained by the same method as the measurement method and calculation method of T-peel peel force in the above-mentioned [T-peel peel force]. The results are shown in Table 1.

[Evaluation of residual adhesion rate]
In the above [T-peel peeling force], the polyester pressure-sensitive adhesive tape used when measuring the T-peel peeling force on the surface layer side of each peelable film (polyester pressure-sensitive adhesive tape after peeling in the measurement) is used. Each was stuck on a stainless steel plate (SUS board) by reciprocating a 2 kg roller twice. Next, with respect to the patch having the stainless steel plate obtained by sticking, the T-peel peeling test was performed at a speed of 1000 mm / min, and the peeling force (X) at that time was measured.
On the other hand, in the above [T-peel peeling force], instead of the film surface on the surface layer side of the peelable film, a Teflon (registered trademark) sheet (Skybed tape MSF-100 made by Chukoh Chemical Industry Co., Ltd. 100 μm thick) A T-peel peel test is conducted in the same manner, except that the polyester adhesive tape is attached to the surface, and the polyester adhesive tape after peeling according to the peel test is a 2 kg roller on a stainless steel plate (SUS plate). It stuck by making 2 reciprocations. Next, with respect to the patch having the stainless steel plate obtained by sticking, the T-peel peeling test was performed at a speed of 1000 mm / min, and the peeling force (Y) at that time was measured.
Subsequently, the residual adhesion rate was determined by the following equation. It is evaluated that the component of the surface layer of a peelable film is easy to transfer to a polyester adhesive tape, so that a residual adhesion rate is small. When the residual adhesion rate is 100%, the component of the surface layer of the peelable film is not transferred to the polyester adhesive tape to the same extent as the component of the surface of the Teflon (registered trademark) sheet is not transferred to the polyester adhesive tape. , Which is the most preferable as the peelable film according to the first embodiment.
The results are shown in Table 1.
Residual adhesion rate (%) = (X) / (Y) × 100

In the peelable films according to the first embodiment and the second embodiment, the residual adhesion ratio is preferably 84% or more, more preferably 87% or more, still more preferably 90% or more, and 93% or more. More preferably, 97% or more is particularly preferable. The residual adhesion rate may be 100%.

Example 1A
99 parts by mass of lauryl acrylate (LA) as monomer a and 1 part by mass of 2-hydroxyethyl acrylate (HEA) as monomer b in a 1 liter flask equipped with a stirrer, a nitrogen introducing pipe, a thermometer and a cooling pipe Then, 0.2 parts by mass of azobisisobutyronitrile (AIBN), 100 parts by mass of toluene, and 100 parts by mass of ethyl acetate were added as a polymerization initiator. Next, in the flask, a polymerization reaction is performed at 80 ° C. for 2 hours in a nitrogen stream, and 1.0 parts by mass of azobisisobutyronitrile is further added, followed by polymerization for 2 hours to obtain an alkyl acrylate-HEA copolymer. A polymer (hereinafter, referred to as "modified acrylic resin (A)")-containing solution (solid content: 30% by mass) was obtained. The weight average molecular weight of the obtained modified acrylic resin (A) was 10.5 × 10 ⁴ .
Further, as a polyester resin α which is a resin (B), Byron (registered trademark) M802 (manufactured by Toyobo Co., Ltd., number average molecular weight (Mn): 3 × 10 ³ , hydroxyl value: 37 mg KOH / g solid content 70 mass%), Nikarak (registered trademark) MW-30 MLF (manufactured by Nippon Carbide Industries Co., Ltd., average 1.3-mer 98% by mass) as a melamine crosslinking agent (D) represented by the general formula (V) (type F described later), acid As a catalyst (E), a dryer 900 (50 mass% of para-toluenesulfonic acid manufactured by Hitachi Chemical Co., Ltd.) was prepared.
Next, a modified acrylic resin (A) -containing solution, a resin (B) different from the modified acrylic resin (A), and a melamine crosslinking agent (D), toluene: methyl ethyl ketone (MEK) = 30: 70 (mass ratio) The acid catalyst (E) was further mixed and stirred after being mixed with the mixed solvent of and stirred. Here, with respect to the modified acrylic resin (A) -containing solution, the resin (B), the melamine crosslinking agent (D), and the acid catalyst (E), 56 mass of the modified acrylic resin (A) in terms of solid content. It mixed and stirred so that it might become part, 44 mass parts of said polyester resins, 6 mass parts of said melamine crosslinking agents, and 0.7 mass parts of said acid catalysts (E). Thereby, the coating liquid 1 of solid content concentration 4.4 mass% and an acid catalyst concentration 0.03 mass% was obtained.
Next, a 38 μm-thick biaxially stretched polyethylene terephthalate film (biaxially stretched PET film, “E5100” manufactured by Toyobo Co., Ltd.) was prepared as a base material layer.
Next, the coating solution 1 is coated on the base material layer using Meyer bar (Shaft diameter: 6.35 mm 製 by Yasuda Seiki Mfg. Co., Ltd., ROD No. 4), and in an explosion-proof drier 140 Dry at 30 ° C. for 30 seconds. Thereby, the peelable film of Example 1A which has a base material layer and a surface layer (thickness of surface layer: 0.2 micrometer) was obtained.

Example 2A
About the said modified acrylic resin (A) containing solution, resin (B), melamine crosslinking agent (D), and an acid catalyst (E), 56 mass parts of said modified acrylic resin (A) in conversion of solid content, respectively 44 parts by mass of polyester resin, 6 parts by mass of the melamine crosslinking agent, and 1.1 parts by mass of the acid catalyst (E) are mixed and stirred to give a coating liquid 2 (solid content: 2.8% by mass, acid catalyst A concentration of 0.03% by mass was obtained. Moreover, about the said coating liquid 2, it coated on the base material layer so that the thickness after drying might be 0.1 micrometer. About the other operation, the peelable film of Example 2A was obtained by performing the same operation as Example 1A.

Example 3A
About the said denatured acrylic resin (A) containing solution, resin (B), a melamine crosslinking agent (D), and an acid catalyst (E), 75 mass parts of said denatured acrylic resin (A) in conversion of solid content, respectively 25 parts by mass of polyester resin, 6 parts by mass of the melamine cross-linking agent, and 0.7 parts by mass of the acid catalyst (E) are mixed and stirred to give a coating liquid 3 (solid content concentration 4.4 mass%, acid catalyst A concentration of 0.03% by mass was obtained. About the other operation, the peelable film of Example 3A was obtained by performing the same operation as Example 1A.

Example 4A
About the said modified acrylic resin (A) containing solution, resin (B), a melamine crosslinking agent (D), and an acid catalyst (E), 95 mass parts of said modified acrylic resins (A) in conversion of solid content, respectively 5 parts by mass of polyester resin, 6 parts by mass of the melamine crosslinking agent, and 0.7 parts by mass of the acid catalyst (E) are mixed and stirred to give a coating liquid 4 (solid content concentration 4.4% by mass, acid catalyst A concentration of 0.03% by mass was obtained. About the other operation, the peelable film of Example 4A was obtained by performing the same operation as Example 1A.

Example 5A
About the said modified acrylic resin (A) containing solution, resin (B), melamine crosslinking agent (D), and an acid catalyst (E), 32 mass parts of said modified acrylic resin (A), respectively in conversion of solid content, 68 parts by mass of a polyester resin, 6 parts by mass of the melamine crosslinking agent, and 0.7 parts by mass of the acid catalyst (E) are mixed and stirred to give a coating liquid 5 (solid content concentration 4.4% by mass, acid catalyst A concentration of 0.03% by mass was obtained. About the other operation, the peelable film of Example 5A was obtained by performing the same operation as Example 1A.

Example 6A
The amount of the azobisisobutyronitrile (AIBN) used and the temperature at the time of the polymerization reaction were changed such that the weight average molecular weight of the modified acrylic resin (A) was 8.1 × 10 ⁴ . About the other operation, the peelable film of Example 6A was obtained by performing the same operation as Example 1A.

Example 7A
The amount of the azobisisobutyronitrile (AIBN) used and the temperature at the time of the polymerization reaction were changed such that the weight average molecular weight of the modified acrylic resin (A) was 5.8 × 10 ⁴ . About the other operation, the peelable film of Example 7A was obtained by performing the same operation as Example 1A.

Example 8A
The amount of the azobisisobutyronitrile (AIBN) used and the temperature at the time of the polymerization reaction were changed so that the weight average molecular weight of the modified acrylic resin (A) was 13.0 × 10 ⁴ . About the other operation, the peelable film of Example 8A was obtained by performing the same operation as Example 1A.

Example 9A
99.5 parts by mass of lauryl acrylate (LA) as monomer a, 2-hydroxyethyl acrylate (HEA) as monomer b in a 1-liter flask equipped with a stirrer, a nitrogen introducing tube, a thermometer and a cooling tube .5 parts by mass, 0.2 parts by mass of azobisisobutyronitrile (AIBN) as an initiator, 100 parts by mass of toluene, and 100 parts by mass of ethyl acetate were added. Next, in the flask, a polymerization reaction is carried out at 80 ° C. for 2 hours in a nitrogen stream, and 1.0 parts by mass of azobisisobutyronitrile is further added, followed by polymerization for 2 hours to obtain a modified acrylic resin ( A) A containing solution (solid content: 30% by mass) was obtained. The weight average molecular weight of the obtained modified acrylic resin (A) was 6.8 × 10 ⁴ . About the other operation, the peelable film of Example 9A was obtained by performing the same operation as Example 1A.

Example 10A
98.0 parts by mass of lauryl acrylate (LA) as monomer a and 2-hydroxyethyl acrylate (HEA) 2 as monomer b in a 1-liter flask equipped with a stirrer, a nitrogen introducing pipe, a thermometer and a cooling pipe .0 parts by mass, 0.2 parts by mass of azobisisobutyronitrile (AIBN) as an initiator, 100 parts by mass of toluene, and 100 parts by mass of ethyl acetate were added. Next, in the flask, a polymerization reaction is carried out at 80 ° C. for 2 hours in a nitrogen stream, and 1.0 parts by mass of azobisisobutyronitrile is further added, followed by polymerization for 2 hours to obtain a modified acrylic resin ( A) A containing solution (solid content: 30% by mass) was obtained. The weight average molecular weight of the obtained modified acrylic resin (A) was 10.3 × 10 ⁴ . About the other operation, the peelable film of Example 10A was obtained by performing the same operation as Example 1A.

Example 11A
In a 1-liter flask equipped with a stirrer, a nitrogen introducing pipe, a thermometer and a cooling pipe, 99.0 parts by mass of isodecyl acrylate (IDAA) as a monomer a, 2-hydroxyethyl acrylate (HEA) as a monomer b 1.0 parts by mass, 0.2 parts by mass of azobisisobutyronitrile (AIBN) as an initiator, 100 parts by mass of toluene, and 100 parts by mass of ethyl acetate were added. Next, in the flask, a polymerization reaction is carried out at 80 ° C. for 2 hours in a nitrogen stream, and 1.0 parts by mass of azobisisobutyronitrile is further added, followed by polymerization for 2 hours to obtain a modified acrylic resin ( A) A containing solution (solid content: 30% by mass) was obtained. The weight average molecular weight of the obtained modified acrylic resin (A) was 10.9 × 10 ⁴ . About the other operation, the peelable film of Example 11A was obtained by performing the same operation as Example 1A.

Example 12A
In a 1-liter flask equipped with a stirrer, a nitrogen introducing pipe, a thermometer and a cooling pipe, 99.0 parts by mass of stearyl acrylate (STA) as a monomer a, 2-hydroxyethyl acrylate (HEA) 1 as a monomer b .0 parts by mass, 0.2 parts by mass of azobisisobutyronitrile (AIBN) as an initiator, 100 parts by mass of toluene, and 100 parts by mass of ethyl acetate were added. Next, in the flask, a polymerization reaction is carried out at 80 ° C. for 2 hours in a nitrogen stream, and 1.0 parts by mass of azobisisobutyronitrile is further added, followed by polymerization for 2 hours to obtain a modified acrylic resin ( A) A containing solution (solid content: 30% by mass) was obtained. The weight average molecular weight of the obtained modified acrylic resin (A) was 7.3 × 10 ⁴ . About the other operation, the peelable film of Example 12A was obtained by performing the same operation as Example 1A.

Example 13A
As resin (B), acrylic resin (ACRIDIC (registered trademark) WMG-521, manufactured by DIC Corporation, Tg = 30 ° C., acid value: 6.5 mg KOH / g, solid content 60 mass%) is used instead of polyester resin The peelable film of Example 13A was obtained in the same manner as Example 1A except for the above.

Example 14A
As polyester resin which is resin (B), instead of polyester resin α (Vyron (registered trademark) M802), polyester resin β (Vyron (registered trademark) 20 SS (manufactured by Toyobo Co., Ltd., number average molecular weight (Mn): 17 × A peelable film of Example 14A was obtained in the same manner as in Example 1A except that 10 ³ , hydroxyl value: 6 mg KOH / g, solid content: 30% by mass) was used.

Example 15A
99 parts by mass of lauryl acrylate (LA) as monomer a and 1 part by mass of 2-hydroxyethyl acrylate (HEA) as monomer b in a 1 liter flask equipped with a stirrer, a nitrogen introducing pipe, a thermometer and a cooling pipe Then, 0.2 parts by mass of azobisisobutyronitrile (AIBN), 100 parts by mass of toluene, and 100 parts by mass of ethyl acetate were added as an initiator. Next, in the flask, a polymerization reaction is carried out at 80 ° C. for 2 hours in a nitrogen stream, and 1.0 parts by mass of azobisisobutyronitrile is further added, followed by polymerization for 2 hours to obtain a modified acrylic resin ( A) A containing solution (solid content: 30% by mass) was obtained. The weight average molecular weight of the obtained modified acrylic resin (A) was 10.5 × 10 ⁴ .
Further, as resin (B) different from the modified acrylic resin (A), polyester resin α (VYLON (registered trademark) M802 (manufactured by Toyobo Co., Ltd., number average molecular weight (Mn): 3 × 10 ³ , hydroxyl value: 37 mg KOH /) g Solids 70% by mass)) Type M (described below as melamine crosslinker (D) (all of the substituents R of the amino group bound to three per constitutional unit are either methoxymethyl or methylol) Nicarak® MS-11 (a registered trademark of Nippon Carbide Industries Co., Ltd., average 1.8-mer 60 mass%) which is a melamine compound having one or more of the substituents R being a methylol group, and an acid As a catalyst (E), a dryer 900 (50 mass% of p-toluenesulfonic acid manufactured by Hitachi Chemical Co., Ltd.) was prepared.
Next, a modified acrylic resin (A) -containing solution, a resin (B) different from the modified acrylic resin (A), and a melamine crosslinking agent (D), toluene: methyl ethyl ketone (MEK) = 30: 70 (mass ratio) The acid catalyst (E) was further mixed and stirred after being mixed with the mixed solvent of and stirred. Here, each of the modified acrylic resin (A) -containing solution, the resin (B) different from the modified acrylic resin (A), the melamine crosslinking agent (D), and the acid catalyst (E) is respectively converted to solid content, 56 parts by mass of the modified acrylic resin (A), 44 parts by mass of the polyester resin, 6 parts by mass of the melamine crosslinking agent, and 1.2 parts by mass of the acid catalyst (E) were mixed and stirred. Thereby, the coating liquid 6 with a solid content concentration of 2.8% by mass and an acid catalyst concentration of 0.05% by mass was obtained.
Next, a 38 μm-thick biaxially stretched polyethylene terephthalate film (biaxially stretched PET film, “E5100” manufactured by Toyobo Co., Ltd.) was prepared as a base material layer.
Next, the coating solution 6 is coated on the base material layer using Meyer bar (Shaft diameter: 6.35 mm 製 by Yasuda Seiki Seisakusho Co., Ltd., ROD No. 4), and in an explosion-proof drier 150 Dry at 60 ° C. for 60 seconds. Thereby, the peelable film of Example 15A which has a base material layer and a surface layer (thickness of surface layer: 0.1 micrometer) was obtained.

Comparative Example 1A
As the melamine cross-linking agent (D), all of the substituents R of the type IM described later (three bonded amino groups per constitutional unit are either a methoxymethyl group, a methylol group or a hydrogen atom, and Nikalac (registered trademark) MX-750 (manufactured by Nippon Carbide Industries Co., Ltd.), which is a melamine compound wherein one or more of the substituents R is a methylol group and one or more of the substituents R is a hydrogen atom An average of 2.2 monomers (80% by mass) was used. About the other operation, the peelable film of Comparative Example 1A was obtained by performing the same operation as Example 1A.

Comparative Example 2A
As the melamine crosslinking agent (D), Nicalac (registered trademark) MS-001 (manufactured by Nippon Carbide Industries Co., Ltd., average: 5.7% by mass, 60% by mass) which is type IM described later was used. About the other operation, the peelable film of Comparative Example 2A was obtained by performing the same operation as in Example 1A.

Comparative Example 3A
Nicalac® MX-750 was used instead of melamine crosslinker (D). About the other operation, the peelable film of Comparative Example 4A was obtained by performing the same operation as Example 15A.

Comparative Example 4A
Nicalac® MS-001 was used instead of the melamine crosslinker (D). About the other operation, the peelable film of Comparative Example 5A was obtained by performing the same operation as Example 15A.

Comparative Example 5A
The modified acrylic resin (A) -containing solution, the resin (B) different from the modified acrylic resin (A), the melamine crosslinking agent (D), and the acid catalyst (E), in terms of solid content, the modified acrylic resin 32 parts by mass of the resin (A), 68 parts by mass of the polyester resin, 6 parts by mass of the melamine crosslinking agent, and 0.7 parts by mass of the acid catalyst (E) A partial concentration of 4.4% by mass and an acid catalyst concentration of 0.03% by mass were obtained. About the other operation, the peelable film of Comparative Example 5A was obtained by performing the same operation as Example 15A.

In Table 1, the meanings of the symbols of the modified acrylic resin (A) are as follows.
LA: lauryl acrylate HEA: 2-hydroxyethyl acrylate IDAA: isodecyl acrylate STA: stearyl acrylate

In addition, about the melamine compound used as crosslinking agent D in Table 1, the substitution type of an amino group is as follows. In addition, the "substituent of an amino group" described below means the group by which the hydrogen atom of amino groups was substituted, and points out R in the said Formula (IV). The group R is a group directly bonded to the nitrogen atom of amino groups.
Type F : a melamine compound (general formula (V)) in which all of the substituents R of the amino group having three bonds per constitutional unit (the total of three substituents R in total of three amino groups) is a methoxymethyl group Melamine compounds represented).
Type M : all of the substituents R of the amino group bound to three per structural unit are either a methoxymethyl group or a methylol group, and at least one of the substituents R is a methylol group Melamine compound.
Type IM : all of the substituents R of the amino group having three bonds per constitutional unit are any of a methoxymethyl group, a methylol group or a hydrogen atom, and at least one of the substituents R is a methylol A melamine compound which is a group, and at least one of the substituents R is a hydrogen atom.

As described above, it was found that the peelable films of Examples 1A to 15A had a very small difference in peel force after heating and before heating, and were also excellent in residual adhesion rate. Furthermore, the peelable films of Examples 1A to 15A have low T-peel peeling force (before heating) and low T-peel peeling force after heating. Therefore, the film according to the first embodiment including Examples 1A to 15A is used particularly in the process of manufacturing an electronic component or an electronic substrate, or in the process of manufacturing a thermosetting resin member such as fiber reinforced plastic. It can be suitably used as a release film or the like.

Example 1B
99 parts by mass of lauryl acrylate (LA) as monomer a and 1 part by mass of 2-hydroxyethyl acrylate (HEA) as monomer b in a 1 liter flask equipped with a stirrer, a nitrogen introducing pipe, a thermometer and a cooling pipe Then, 0.2 parts by mass of azobisisobutyronitrile (AIBN), 100 parts by mass of toluene, and 100 parts by mass of ethyl acetate were added as a polymerization initiator. Next, in the flask, a polymerization reaction is performed at 80 ° C. for 2 hours in a nitrogen stream, 0.2 parts by mass of azobisisobutyronitrile is further added, and then polymerization is performed for 2 hours to obtain a modified acrylic resin ( A) A containing solution (solid content: 30% by mass) was obtained. The weight average molecular weight of the obtained modified acrylic resin (A) was 10.5 × 10 ⁴ .
Further, as resin (B) different from the modified acrylic resin (A), polyester resin α (VYLON (registered trademark) M802 (manufactured by Toyobo Co., Ltd., number average molecular weight (Mn): 3 × 10 ³ , hydroxyl value: 37 mg KOH /) g 70% solids by weight, Tg = 60 ° C.), all of the substituents R of the amino group bound three per constitutional unit as the melamine crosslinker (D) (ie the substituents R of the six amino groups), Nikalac (registered trademark) MS-11 (made by Nippon Carbide Industries Co., Ltd., an average of 1.) which is a melamine compound which is a methoxymethyl group or a methylol group, and at least one of the substituents R is a methylol group. An octamer (60% by mass) and a dryer 900 (50% by mass of p-toluenesulfonic acid manufactured by Hitachi Chemical Co., Ltd.) were prepared as an acid catalyst (E).
Next, a modified acrylic resin (A) -containing solution, a resin (B) different from the modified acrylic resin (A), and a melamine crosslinking agent (D), toluene: methyl ethyl ketone (MEK) = 30: 70 (mass ratio) The acid catalyst (E) was further mixed and stirred after being mixed with the mixed solvent of and stirred. Here, each of the modified acrylic resin (A) -containing solution, the resin (B) different from the modified acrylic resin (A), the melamine crosslinking agent (D), and the acid catalyst (E) is respectively converted to solid content, 56 parts by mass of the modified acrylic resin (A), 44 parts by mass of the polyester resin, 6 parts by mass of the melamine crosslinking agent, and 1.2 parts by mass of the acid catalyst (E) were mixed and stirred. Thereby, the coating liquid 1 of solid content concentration 4.4 mass% and an acid catalyst concentration 0.05 mass% was obtained.
Next, a 38 μm-thick biaxially stretched polyethylene terephthalate film (biaxially stretched PET film, “E5100” manufactured by Toyobo Co., Ltd.) was prepared as a base material layer.
Next, the coating solution 1 is coated on the base material layer using Meyer bar (Shaft diameter: 6.35 mm 製 by Yasuda Seiki Seisakusho Co., Ltd., ROD No. 4), and in an explosion-proof drier 150 Dry at 60 ° C. for 60 seconds. Thereby, the peelable film of Example 1 B which has a base material layer and a surface layer (thickness of surface layer: 0.2 micrometer) was obtained.

Example 2B
About the said denatured acrylic resin (A) containing solution, resin (B), a melamine crosslinking agent (D), and an acid catalyst (E), 75 mass parts of said denatured acrylic resin (A) in conversion of solid content, respectively 25 parts by mass of the polyester resin (B), 6 parts by mass of the melamine crosslinking agent (D), and 1.1 parts by mass of the acid catalyst (E) are mixed and stirred to obtain a coating liquid 2 (solids concentration 4. 4 mass% and an acid catalyst concentration of 0.05 mass% were obtained. About the other operation, the peelable film of Example 2B was obtained by performing the same operation as Example 1B.

Example 3B
About the said modified acrylic resin (A) containing solution, resin (B), a melamine crosslinking agent (D), and an acid catalyst (E), 95 mass parts of said modified acrylic resins (A) in conversion of solid content, respectively It mixes so that it may become 5 mass parts of polyester resin (B), 6 mass parts of said melamine crosslinking agents (D), and 1.2 mass parts of said acid catalysts (E), it stirs, and coating liquid 3 (solid content concentration 4. 4 mass% and an acid catalyst concentration of 0.05 mass% were obtained. About the other operation, the peelable film of Example 3B was obtained by performing the same operation as Example 1B.

Example 4B
Acrylic resin (Acridic (registered trademark) WMG-521, manufactured by DIC Corporation, Tg = 30 ° C., acid value: 6.5 mg KOH / g, instead of polyester resin (Vyron (registered trademark) M802) as resin (B) A peelable film of Example 4B was obtained in the same manner as in Example 1B, except that a solid content of 60% by mass was used.

Comparative Example 1B
About the said modified acrylic resin (A) containing solution, resin (B), melamine crosslinking agent (D), and an acid catalyst (E), 32 mass parts of said modified acrylic resin (A), respectively in conversion of solid content, It mixes so that it may become 68 mass parts of polyester resin (B), 6 mass parts of the said melamine crosslinking agents (D), and 1.2 mass parts of the said acid catalysts (E), it stirs, and coating liquid 4 (solid content concentration 4. 4 mass% and an acid catalyst concentration of 0.05 mass% were obtained. About the other operation, the peelable film of Comparative Example 1B was obtained by performing the same operation as Example 1B.

Comparative Example 2B
About the said modified acrylic resin (A) containing solution, resin (B), melamine crosslinking agent (D), and an acid catalyst (E), 10 mass parts of said modified acrylic resin (A) in conversion of solid content, respectively 90 parts by mass of the polyester resin (B), 6 parts by mass of the melamine crosslinking agent (D), and 1.2 parts by mass of the acid catalyst (E) are mixed and stirred to give a coating solution 5 (solids concentration 4. 4 mass% and an acid catalyst concentration of 0.05 mass% were obtained. About the other operation, the peelable film of Comparative Example 2B was obtained by performing the same operation as Example 1B.

Comparative Example 3B
About the said modified acrylic resin (A) containing solution, resin (B), melamine crosslinking agent (D), and an acid catalyst (E), 0 mass parts of said modified acrylic resin (A) in conversion of solid content, respectively 100 parts by mass of the polyester resin (B), 6 parts by mass of the melamine crosslinking agent (D), and 1.2 parts by mass of the acid catalyst (E) are mixed and stirred to give a coating solution 6 (solids concentration 4. 4 mass% and an acid catalyst concentration of 0.05 mass% were obtained. About the other operation, the peelable film of Comparative Example 3B was obtained by performing the same operation as Example 1B.

Comparative Example 4B
About the said modified acrylic resin (A) containing solution, resin (B), melamine crosslinking agent (D), and an acid catalyst (E), 46 mass parts of said modified acrylic resin (A) in conversion of solid content, respectively 54 parts by mass of the polyester resin (B), 6 parts by mass of the melamine crosslinking agent (D), and 1.2 parts by mass of the acid catalyst (E) are mixed and stirred to obtain a coating solution 7 (solids concentration 4. 4 mass% and an acid catalyst concentration of 0.05 mass% were obtained. About the other operation, the peelable film of Comparative Example 4B was obtained by performing the same operation as in Example 1B.

Films of Examples 1B to 4B and Comparative Examples 1B to 4B
(I) M _C5 / M _C40 (where M _C5 is the ratio of the content of carbon to the total element content present at a depth of 5 nm vertically from the outermost surface in the surface layer to the substrate layer) M _C5 is also simply referred to as the carbon element ratio at a depth of 5 nm, and M _C40 is the carbon relative to the total element content present at a depth of 40 nm vertically from the outermost surface in the surface layer to the base layer. The ratio of the content of _{C 40} is simply referred to as the carbon element ratio at a depth of 40 nm.
(Ii) M _A / M _B (wherein M _A is a part by mass of the modified acrylic resin (A) containing the constitutional unit represented by the above structural formula (I), which is contained in the surface layer, M _B is a part by mass of the polyester resin (B) contained in the surface layer, and the above M _A and M _B are both in terms of solid content.)
(Iii) T-peel peeling force (iv) Heat resistance evaluation (T-peel peeling force after heating)
(V) Peeling force difference (T-peel peeling force after heating-T-peel peeling force before heating)
(Vi) The residual adhesion results are shown in Table 2. In addition, said (v) peeling-force difference is calculated by the difference of said (iv) and said (iii).

As described above, the peelable films of Examples 1B to 4B have low T-peel peeling force (before heating) and low T-peel peeling force after heating. Furthermore, it was found that the peelable films of Examples 1B to 4B had a very small difference in peel force after heating and before heating, and were also excellent in residual adhesion rate. Therefore, the film according to the second embodiment including the examples 1B to 4B is used particularly in the process of manufacturing an electronic component or an electronic substrate, or in the process of manufacturing a thermosetting resin member such as fiber reinforced plastic. It can be suitably used as a release film or the like.

Claims

A peelable film having a surface layer on a substrate layer,
The main component forming the surface layer is a resin component,
The resin component includes a modified acrylic resin (A) having an alkyl component and a crosslinkable functional group, a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D).
The modified acrylic resin (A) has at least the following general formula (I):

(In the above general formula (I), R 1 represents a methyl group or a hydrogen atom, and R 2 represents an alkyl group having 10 to 18 carbon atoms.)
Contains the constitutional unit represented by
The crosslinkable agent (D) is a releasable film, wherein the crosslinker (D) is a melamine compound having a structure in which all hydrogen atoms of amino groups are substituted with at least one of an alkoxyalkyl group and an alkanol group.
The modified acrylic resin (A) has the following general formula (II):

[In the above general formula (II), R a represents a methyl group or a hydrogen atom, R b represents -CH 2 CH 2 OH, -CH 2 -CHOH-CH 3 , -CH 2 CH 2 CH 2 OH, -CH 2 -CHOH-CH 2 CH 3 , -CH 2 CH 2 -CHOH-CH 3 , or -CH 2 CH 2 CH 2 CH 2 OH is shown. ]
The peelable film of Claim 1 containing the structural unit represented by these.
The peelable film according to claim 1 or 2, wherein the weight average molecular weight of the modified acrylic resin (A) is 5 × 10 4 to 15 × 10 4 .
The content of the resin (B) in the surface layer is 2 parts by mass or more based on 100 parts by mass of the total of the modified acrylic resin (A) and the resin (B) constituting the surface layer. The peelable film according to any one of claims 1 to 3.
The content of the resin (B) in the surface layer is less than 50 parts by mass, based on 100 parts by mass of the total of the modified acrylic resin (A) and the resin (B) constituting the surface layer. The peelable film according to any one of claims 1 to 4.
The releasable film according to any one of claims 1 to 5, wherein the alkoxyalkyl group has 2 to 5 carbon atoms, and the alkanol group has 1 to 3 carbon atoms.
The releasability according to any one of claims 1 to 6, wherein the resin (B) different from the modified acrylic resin (A) is at least one selected from the group consisting of a polyester resin and an acrylic resin. the film.
A method for producing a peelable film having a surface layer on a substrate layer,
Forming the surface layer on the base layer,
The main component forming the surface layer is a resin component,
The resin component includes a modified acrylic resin (A) having an alkyl component and a crosslinkable functional group, a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D).
The modified acrylic resin (A) has at least the following general formula (I):

(In the above general formula (I), R 1 represents a methyl group or a hydrogen atom, and R 2 represents an alkyl group having 10 to 18 carbon atoms.)
Contains the constitutional unit represented by
The method for producing a release film, wherein the crosslinking agent (D) is a melamine compound having a structure in which all hydrogen atoms of amino groups are substituted with at least one of alkoxyalkyl groups and alkanol groups.
A peelable film having a surface layer on a substrate layer,
A peelable film having a carbon content ratio MC5 (atomic%) to a total elemental content present at a depth of 5 nm vertically from the outermost surface in the surface layer toward the base material layer.
The main component forming the surface layer is a resin component,
The resin component includes a modified acrylic resin (A) having an alkyl component and a crosslinkable functional group, a resin (B) different from the modified acrylic resin (A), and a crosslinking agent (D).
The modified acrylic resin (A) has at least the following general formula (I):

(In the above general formula (I), R 1 represents a methyl group or a hydrogen atom, and R 2 represents an alkyl group having 10 to 18 carbon atoms.)
The peelable film of Claim 9 containing the structural unit represented by these.
The content of the resin (B) in the surface layer is 2 parts by mass or more based on 100 parts by mass of the total of the modified acrylic resin (A) and the resin (B) constituting the surface layer. The peelable film according to claim 10.
The content of the resin (B) in the surface layer is less than 50 mass based on 100 parts by mass of the total of the modified acrylic resin (A) and the resin (B) constituting the surface layer. Item 12. The peelable film according to Item 10 or 11.
And the M C5, the ratio M C5 between the content ratio of carbon M C40 (atomic%) with respect to the total element content at the position of the vertical depth 40nm towards the base layer from the outermost surface of the surface layer The releasable film according to any one of claims 9 to 12, wherein / M C40 is 1.01 C M C5 / M C40 10 1.10.
The releasability according to any one of claims 9 to 13, wherein the resin (B) different from the modified acrylic resin (A) is at least one selected from the group consisting of polyester resins and acrylic resins. the film.