KR20160142286A - Side chain crystalline polymer, thermosensitive adhesive agent, thermosensitive adhesive sheet, and thermosensitive adhesive tape - Google Patents

Abstract

The side chain crystalline polymer of the present invention is composed of a graft copolymer of a crystalline macromonomer and an amorphous monomer. Further, the thermosensitive adhesive of the present invention contains an acrylic pressure-sensitive adhesive and the side chain crystalline polymer, and the adhesive strength is lowered at a temperature higher than the melting point of the side chain crystalline polymer. The thermosensitive adhesive sheet of the present invention is composed of the thermosensitive adhesive. The thermosensitive adhesive tape of the present invention comprises a base film and a pressure-sensitive adhesive layer comprising the thermosensitive pressure-sensitive adhesive laminated on at least one side of the base film.

Description

THERMOSENSITIVE ADHESIVE SHEET, THERMOSENSITIVE ADHESIVE TAPE, THERMOSENSITIVE ADHESIVE TAPE, THERMOSENSITIVE ADHESIVE TAPE, THERMOSENSITIVE ADHESIVE TAPE, THERMOSENSITIVE ADHESIVE TAPE,

The present invention relates to a side chain crystalline polymer, a thermosensitive adhesive, a thermosensitive adhesive sheet and a thermosensitive adhesive tape.

The thermosensitive adhesive contains a pressure-sensitive adhesive and a side chain crystalline polymer, and the adhesive strength is lowered at a temperature higher than the melting point of the side chain crystalline polymer. Sensitive adhesive tape, which is a form of use of a thermosensitive adhesive, is used for temporarily fixing parts in the fields of electronic parts, semiconductor wafers, and liquid crystals (see, for example, Patent Document 1). The conventional side chain crystalline polymer described in Patent Document 1 is composed of a random copolymer. As the thermosensitive adhesive, it is preferable that the adhesive property is excellent.

Japanese Patent Application Laid-Open No. 2000-355684

A problem to be solved by the present invention is to provide a side chain crystalline polymer which can be a thermosensitive adhesive excellent in adhesive property, a thermosensitive pressure-sensitive adhesive containing it, a thermosensitive pressure-sensitive adhesive sheet and a thermosensitive pressure-sensitive adhesive tape.

The side chain crystalline polymer of the present invention is composed of a graft copolymer of a crystalline macromonomer and an amorphous monomer.

The thermosensitive adhesive of the present invention contains an acrylic pressure-sensitive adhesive and the side chain crystalline polymer, and the adhesive strength is lowered at a temperature higher than the melting point of the side chain crystalline polymer.

The thermosensitive adhesive sheet of the present invention is composed of the thermosensitive adhesive.

The thermosensitive adhesive tape of the present invention comprises a base film and a pressure-sensitive adhesive layer comprising the thermosensitive pressure-sensitive adhesive laminated on at least one side of the base film.

(Effects of the Invention)

According to the present invention, there is an effect that the adhesive property is excellent.

[Side chain crystalline polymer]

Hereinafter, a side chain crystalline polymer according to one embodiment of the present invention will be described. The side chain crystalline polymer of the present embodiment is, for example, a graft copolymer as represented by the following general formula (I).

Wherein R ₁ represents a straight chain alkyl group having a carbon number of 16 or more. R ₂ represents a hydrogen atom or a methyl group. R ₃ and R ₄ are the same or different and each represents an alkyl group having 1 to 12 carbon atoms. n represents an integer of 2 to 80; x represents an integer of 10 to 90, and y and z represent integers such that y + z = 10 to 90. Also, x + y + z = 100.]

The side chain crystalline polymer represented by the above general formula (I) is a graft copolymer of a crystalline macromonomer represented by the following general formula (II) and an amorphous monomer.

Wherein R ₁ , R ₂ and n are the same as R ₁ , R ₂ and n in the general formula (I).

In the present embodiment, the crystalline macromonomer represented by the general formula (II) constitutes the branch portion of the graft copolymer and is a moiety functioning as a crystalline component in the graft copolymer. In addition, the amorphous monomer constitutes the stem (main chain) of the graft copolymer and functions as a compatible component with an acrylic pressure-sensitive adhesive which will be described later. When the side chain crystalline polymer of the present embodiment comprising a graft copolymer of a crystalline macromonomer and an amorphous monomer is contained in an acrylic pressure-sensitive adhesive to obtain a pressure-sensitive adhesive, excellent effects on adhesive properties can be obtained. For this reason, the following reason is presumed.

Since the above-described conventional side chain crystalline polymer is composed of a random copolymer, it is presumed that the crystalline component and the compatible component also exist randomly in the copolymer, and each component is in a state in which it is difficult to sufficiently function. Since the side chain crystalline polymer of the present embodiment is present in the copolymer together with the crystalline component and the compatibilizing component, the functions of each component are sufficiently exhibited, and as a result, when the thermosensitive pressure- Is expected to exert. Concretely, when the side chain crystalline polymer of the present embodiment is contained in an acrylic pressure-sensitive adhesive to form a pressure-sensitive adhesive, the initial pressure-sensitive adhesive force can be sufficiently maintained at a temperature lower than the melting point of the side chain crystalline polymer. The adhesive force can be sufficiently lowered. Hereinafter, the structure of the side chain crystalline polymer of the present embodiment will be described in detail.

The side chain crystalline polymer of the present embodiment has a melting point. The side chain crystalline polymer of the present embodiment crystallizes at a temperature lower than the melting point and exhibits fluidity at the temperature higher than the melting point. That is, the side chain crystalline polymer of the present embodiment has a thermosensitive property that reversibly causes a crystalline state and a fluidized state in response to a temperature change.

The melting point is a temperature at which a specific portion of a polymer that has been initially aligned in an ordered arrangement by a predetermined equilibrium process is in an unordered state and is measured by a differential scanning calorimeter (DSC) under a measurement condition of 10 캜 / Quot; value "

The melting point of the side chain crystalline polymer of the present embodiment is not particularly limited, and is preferably higher than room temperature (23 캜), for example. The melting point can be adjusted by changing the composition and the like of the side chain crystalline polymer.

The weight average molecular weight of the side chain crystalline polymer of the present embodiment is preferably larger than the weight average molecular weight of the crystalline macromonomer and is 20,000 or less. The lower limit value of the weight average molecular weight is not particularly limited as long as the effect of the present embodiment can be obtained, but it is preferably 500 or more. The weight average molecular weight is a value obtained by measuring the side chain crystalline polymer by gel permeation chromatography (GPC) and converting the measured value into polystyrene.

The constitution of the side chain crystalline polymer of the present embodiment is not limited to the constitution of the graft polymer represented by the general formula (I) as long as it is composed of a graft copolymer of a crystalline macromonomer and an amorphous monomer. The side chain crystalline polymer of the present embodiment may be used alone without being used in combination with an acrylic pressure-sensitive adhesive described later. When the side chain crystalline polymer of the present embodiment is used alone, it is possible to provide a thermosensitive pressure-sensitive adhesive whose adhesive strength is lowered at a temperature lower than the melting point of the side chain crystalline polymer.

(Crystalline macromonomer)

The crystalline macromonomer means a high molecular weight monomer having crystallinity and having a polymerizable double bond polymerizable at one terminal with an amorphous monomer. The crystalline macromonomer in the present embodiment is a macromonomer represented by the above-mentioned general formula (II) having a (meth) acrylic acid ester group at one end. The carbon-carbon unsaturated bond in the (meth) acrylic acid ester group is a polymerizable double bond copolymerizable with the amorphous monomer. In formula (II), R ₁ representing a linear alkyl group having at least 16 carbon atoms functions as a crystalline site.

The weight average molecular weight of the crystalline macromonomer in the present embodiment is preferably 10,000 or less. The lower limit value of the weight average molecular weight is not particularly limited as long as the effect of the present embodiment can be obtained, but it is preferably 400 or more. The weight average molecular weight is a value obtained by measuring the crystalline macromonomer by GPC and converting the measured value into polystyrene.

The constitution of the crystalline macromonomer of the present embodiment is not particularly limited as long as it is a high molecular weight monomer having a plurality of predetermined linear alkyl groups and having a polymerizable double bond polymerizable at one terminal with an amorphous monomer, The present invention is not limited to this configuration.

(Amorphous monomer)

Examples of the amorphous monomer in the present embodiment include (meth) acrylate having an alkyl group having 1 to 12 carbon atoms, a polar monomer, a reactive polysiloxane compound, vinyl acetate, and styrene. In other words, the amorphous monomer in the present embodiment is preferably at least one member selected from (meth) acrylate having a C1-C12 alkyl group, a polar monomer, a reactive polysiloxane compound, vinyl acetate and styrene. Further, (meth) acrylate means methacrylate or acrylate.

Examples of the (meth) acrylate having an alkyl group having 1 to 12 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate and hexyl (meth) . These may be used alone or in combination of two or more. Among these exemplified ones, it is preferable that the cohesive force is high in view of suppressing a decrease in adhesive strength at the time of temperature rise. Specific examples thereof include methyl acrylate and the like. Thus, it is preferred that the amorphous monomer comprises at least methyl acrylate.

Examples of the polar monomer include ethylenically unsaturated monomers having a carboxyl group such as (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid; And ethylenically unsaturated monomers having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 2-hydroxyhexyl (meth) acrylate. These may be used alone or in combination of two or more.

The reactive polysiloxane compound means a polysiloxane compound having a functional group exhibiting reactivity and having a siloxane bond in its main chain. Examples of the functional group exhibiting reactivity include groups having an ethylenically unsaturated double bond such as a vinyl group, an allyl group, a (meth) acrylic group, a (meth) acryloyl group, or a (meth) An epoxy group (including a glycidyl group and an epoxycycloalkyl group), a mercapto group, a carbino group, a carboxyl group, a silanol group, a phenol group, an amino group, and a hydroxyl group.

These functional groups may be introduced into the side chain of the main chain or both ends of the main chain. That is, the reactive polysiloxane compound may be classified into four types, namely, a so-called side chain type, a so-called end type, a one end type and a side chain type, depending on the bonding position of the functional group to be introduced. A terminal reactive polysiloxane compound is preferred.

Specific examples of the one-end reactive polysiloxane compound include a modified polydimethylsiloxane compound represented by the following general formula (III).

Wherein R ₅ represents an alkyl group. R ₆ represents a group: CH ₂ ═CHCOOR ⁷ - or CH ₂ ═C (CH ₃ ) COOR ⁷ - (wherein R ⁷ represents an alkylene group). and r represents an integer of 5 to 200.]

Examples of the alkyl group represented by R ₅ in the general formula (III) include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, A straight chain or branched alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, a butyl group, an isopropyl group, an isobutyl group, a t-butyl group, an isopentyl group, a neopentyl group and a hexyl group.

Examples of the alkylene group represented by R ⁷ include linear or branched alkyl groups having 1 to 6 carbon atoms such as a methylene group, an ethylene group, a trimethylene group, a methylethylene group, a propylene group, a tetramethylene group, a pentamethylene group and a hexamethylene group Branched alkylene groups, and the like.

Specific examples of the modified polydimethylsiloxane compound represented by the general formula (III) include compounds represented by the following general formula (IIIa).

[Wherein R ₅ , R ⁷ and r are as defined in formula (III)].

Commercially available modified polydimethylsiloxane compounds can be used. Specific examples of the modified polydimethylsiloxane compound include terminally reactive silicone oil "X-22-2404", "X-24-8201", " X-22-174DX ", " X-22-2426 ", and the like.

[Process for producing crystalline macromonomer]

Next, with regard to a method for producing a crystalline macromonomer according to an embodiment of the present invention, a crystalline macromonomer represented by the above-mentioned general formula (II) (hereinafter referred to as "crystalline macromonomer (II)" ) Will be described in detail as an example.

In the present embodiment, as shown in the following reaction formula, first, the crystalline monomer (IV) and, if necessary, other monomers are subjected to radical polymerization in the presence of a chain transfer agent (V) having a hydroxyl group, To obtain a prepolymer (VI) having a practical group. Subsequently, the functional group-having functional group (VII) having a polymerizable double bond is reacted with the hydroxyl group of the prepolymer (VI) to obtain a crystalline macromonomer (II).

Wherein R ₁ and n are as defined in the general formula (I).

Wherein R ₁ , R ₂ and n are as defined in the general formula (I).

Examples of the crystalline monomer (IV) include (meth) acrylates having a linear alkyl group having 16 or more carbon atoms, preferably 16 to 50 carbon atoms, and more preferably 16 to 22 carbon atoms. Examples of the (meth) acrylate having a straight chain alkyl group having 16 or more carbon atoms include cetyl (meth) acrylate, stearyl (meth) acrylate, eicosyl (meth) acrylate, . These may be used alone or in combination of two or more. The straight-chain alkyl group having 16 or more carbon atoms in the (meth) acrylate described above corresponds to R ₁ .

The other monomers are not particularly limited as long as they are copolymerizable with the crystalline monomer (IV), and from the viewpoint of compatibility with the amorphous monomer, those which are exemplified as the amorphous monomer are preferable. These may be used alone or in combination of two or more.

The polymerization ratio of the crystalline monomer (IV) and other monomers is not particularly limited, and preferably 90 to 100 parts by weight of the crystalline monomer (IV) and 0 to 10 parts by weight of the other monomers.

As the chain transfer agent (V) in the present embodiment, mercaptoethanol is used, but it is not limited thereto. The chain transfer agent (V) may be any as long as it can introduce a hydroxyl group into the prepolymer (VI), and examples thereof include mercaptopropanol, mercaptobutanol, mercapto pentanol, mercapto 1-octanol, , Thiol compounds having hydroxyl groups such as mercaptocyclopentanol, mercaptocyclohexanol and mercaptophenol, and the like can be used. The amount of the chain transfer agent (V) to be used is generally 0.1 to 25 parts by weight, preferably 3 to 15 parts by weight, based on 100 parts by weight of the total amount of the crystalline monomer (IV) and other monomers.

The polymerization reaction of the prepolymer (VI) may be carried out in the absence of a solvent or in a polymerization solvent. As the polymerization solvent, for example, aromatic hydrocarbons such as toluene and xylene; Aliphatic esters such as ethyl acetate and butyl acetate; Alicyclic hydrocarbons such as cyclohexane; And aliphatic hydrocarbons such as hexane and pentane. These may be used alone or in combination of two or more. The amount of the polymerization solvent to be used may be appropriately determined.

The polymerization temperature of the prepolymer (VI) is usually 20 to 200 캜, preferably 40 to 120 캜. The polymerization time is usually 1 to 24 hours, preferably 1 to 7 hours. The reaction pressure is not particularly limited, and may be atmospheric pressure (atmospheric pressure), reduced pressure, or pressurized. The polymerization reaction is preferably carried out in an inert gas atmosphere such as nitrogen gas.

In the polymerization reaction of the prepolymer (VI), a polymerization initiator may be used. Examples of the polymerization initiator include azo-based polymer polymerization initiators such as 2,2'-azobisisobutylonitrile and 2,2'-azobis (2,4-dimethylvaleronitrile); And organic peroxides such as benzoyl peroxide, dimethyl ethyl ketone peroxide, and lauryl peroxide. Specific examples of the azo-based polymer polymerization initiator include "ABN-R", "ABN-V", "ABN-E" and the like manufactured by Nihon Hydrazine Kogyo Co., Examples of the organic peroxide include " pertetra A ", " perhexyl ND ", and " perbutyl ND " These may be used alone or in combination of two or more. The amount of the polymerization initiator to be used may be appropriately determined.

The functionalizing agent (VII) of the present embodiment is di (meth) acrylic acid anhydride. Therefore, the crystalline macromonomer (II) of the present embodiment can be obtained by reacting a crystalline monomer (IV) containing (meth) acrylate having at least a linear alkyl group having at least 16 carbon atoms with a chain transfer agent (V) having a hydroxyl group the under is obtained by radical polymerization, the prepolymer (VI) having a hydroxyl group at one end of di (meth) acrylic acid anhydride functional groups agent is obtained by reacting (VII), a carbon number of 16 or more straight chain alkyl group represented by R ₁ in the side chain And a macromonomer having a polymerizable double bond polymerizable with an amorphous monomer at one end thereof.

As the functionalizing agent (VII) in the present embodiment, di (meth) acrylic acid anhydride is used as described above, but the present invention is not limited thereto. That is, the functionalizing agent (VII) can be a crystalline macromonomer (II) having a polymerizable double bond capable of polymerizing with an amorphous monomer at one end by reacting with a hydroxyl group of the prepolymer (VI) It is not limited to an acid anhydride such as an anhydride.

The amount of the functionalizing agent (VII) to be used is not particularly limited, but is preferably larger than the amount of the chain transfer agent (V) used, more preferably 1.05 to 1.1 times as much as the amount of the chain transfer agent (V). In order to efficiently obtain the side chain crystalline polymer, it is preferable that the residual functionalizing agent (VII) is removed by reacting with water or the like.

The reaction of the prepolymer (VI) with the crystalline macromonomer (II) can be carried out in a solvent. Examples of the solvent include those exemplified as polymerization solvents for the prepolymer (VI). The amount of the polymerization solvent to be used may be appropriately determined.

The reaction temperature at which the prepolymer (VI) is used as the crystalline macromonomer (II) is usually 50 to 150 占 폚, preferably 50 to 130 占 폚. The reaction time is usually 10 minutes to 8 hours, preferably 30 minutes to 4 hours. The reaction pressure is not particularly limited, and may be atmospheric pressure (atmospheric pressure), reduced pressure, or pressurized.

In the reaction of using the prepolymer (VI) as the crystalline macromonomer (II), a polymerization inhibitor may be used. Instead of using the polymerization inhibitor, mixed air may be bubbled, or they may be used in combination.

The method for producing the crystalline macromonomer (II) is not limited to the above-mentioned reaction formula as long as the crystalline macromonomer (II) can be obtained.

[Method for producing side chain crystalline polymer]

Next, with respect to the process for producing a side chain crystalline polymer according to an embodiment of the present invention, the side chain crystalline polymer (hereinafter referred to as " side chain crystalline polymer (I) " ) Will be described in detail as an example.

In the present embodiment, as shown in the following reaction formula, a side chain crystalline polymer (I) is obtained by a macromonomer method in which the above-mentioned crystalline macromonomer (II) is copolymerized with amorphous monomers (VIII, IX). According to this macromonomer method, the crystalline macromonomer (II) is copolymerized in the copolymer (stem portion) of the amorphous monomer (VIII, IX) through the polymerizable double bond and the residue of the crystalline macromonomer Thereby forming branches. As a result, the side chain crystalline polymer (I) as a graft copolymer can be efficiently obtained. In addition, the homogeneity of the polymer forming the branch portion can be easily achieved, and the molecular weight of the branch portion can be easily controlled. The amorphous monomers (VIII, IX) of the present embodiment are (meth) acrylates having an alkyl group having 1 to 12 carbon atoms, but are not limited thereto.

R ₁ , R ₂ , R ₃ , R ₄ , x, y, z and n are as defined in formula (I).

The polymerization ratio of the crystalline macromonomer (II) is preferably 10 to 90 parts by weight, more preferably 20 to 80 parts by weight. The polymerization ratio of the amorphous monomer (VIII, IX) is preferably 10 to 90 parts by weight, more preferably 20 to 80 parts by weight.

The polymerization reaction of the graft copolymer may be carried out in the absence of a solvent or in a polymerization solvent. The polymerization solvent is not particularly limited, and examples thereof include those exemplified as polymerization solvents for the prepolymer (VI). The amount of the polymerization solvent to be used may be appropriately determined.

In the polymerization reaction of the graft copolymer, a chain transfer agent may be used to adjust the molecular weight distribution of the graft copolymer. The chain transfer agent is not particularly limited, and examples thereof include sulfur-containing compounds such as dodecanethiol, thioglycolic acid, thioacetic acid, and mercaptoethanol; Phosphorous acid, phosphorous acid compounds such as sodium phosphite; Hypophosphorous acid compounds such as hypophosphorous acid, hypophosphorous acid and sodium hypophosphite; And alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and n-butyl alcohol. These may be used alone or in combination of two or more. The amount of the chain transfer agent to be used may be appropriately determined.

The polymerization temperature of the graft copolymer is usually 20 to 200 deg. C, preferably 40 to 120 deg. The polymerization time is usually 1 to 24 hours, preferably 1 to 7 hours. The reaction pressure is not particularly limited, and may be atmospheric pressure (atmospheric pressure), reduced pressure, or pressurized. The polymerization reaction is preferably carried out in an inert gas atmosphere such as nitrogen gas.

In the polymerization reaction of the graft copolymer, a polymerization initiator may be used. The polymerization initiator is not particularly limited, and examples include those exemplified as the polymerization initiator of the prepolymer (VI). The amount of the polymerization initiator to be used may be appropriately determined.

The method for producing the side chain crystalline polymer (I) is not limited to the above-mentioned reaction formula as far as the side chain crystalline polymer (I) is obtained.

[Pressure Sensitive Adhesive]

The thermosensitive adhesive according to one embodiment of the present invention contains an acrylic pressure-sensitive adhesive and the above-described side chain crystalline polymer. The thermosensitive adhesive refers to a pressure sensitive adhesive whose adhesive force is changed in response to a change in temperature.

The thermosensitive adhesive of the present embodiment contains a side chain crystalline polymer in such a ratio that the adhesive force decreases when the side chain crystalline polymer exhibits fluidity at a preset switching temperature or higher, that is, at a temperature higher than the melting point of the side chain crystalline polymer. Therefore, when the thermosensitive pressure-sensitive adhesive of the present embodiment is heated to a temperature higher than the melting point of the side chain crystalline polymer, the side chain crystalline polymer exhibits fluidity, which deteriorates the tackiness of the pressure-sensitive adhesive, It can be easily separated.

The side chain crystalline polymer is preferably blended in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the acrylic pressure-sensitive adhesive, but is not limited thereto. That is, the side chain crystalline polymer is not limited to the exemplified compound as long as the initial adhesive force of the thermosensitive adhesive is higher than 0 N / 25 mm, and it can be compounded in a desired ratio.

Sensitive adhesive of the present embodiment has high transparency because it contains an acrylic pressure-sensitive adhesive having compatibility with the stem portion of the above-described side chain crystalline polymer. Examples of the monomer constituting the acrylic pressure-sensitive adhesive include alkyl groups having 1 to 12 carbon atoms such as ethylhexyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (Meth) acrylate; (Meth) acrylate having a hydroxyalkyl group such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxyhexyl (meth) acrylate. These monomers may be used singly or in combination of two or more.

The weight average molecular weight of the acrylic pressure-sensitive adhesive is preferably 250,000 to 150,000. When the weight-average molecular weight is too small, there is a possibility that the so-called pool residue, in which the pressure-sensitive adhesive remains on the member to be attached, may be increased when the member to be attached is separated. In addition, if the weight average molecular weight is too large, the cohesive force of the pressure sensitive adhesive becomes too high, and the adhesive strength may be lowered. The weight average molecular weight is a value obtained by measuring an acrylic pressure-sensitive adhesive by GPC and converting the measured value into polystyrene.

The method for producing the thermosensitive pressure-sensitive adhesive is not particularly limited. For example, first, the side chain crystalline polymer is adjusted with a solvent to obtain a copolymer solution. Next, the monomer constituting the acrylic pressure-sensitive adhesive is polymerized to obtain an acrylic pressure-sensitive adhesive. Then, the co-aggregate solution and the pressure-sensitive adhesive are mixed to obtain a pressure-sensitive adhesive solution, and the obtained pressure-sensitive adhesive solution is dried.

The polymerization method of the monomer constituting the acrylic pressure-sensitive adhesive is not particularly limited, and for example, a solution polymerization method, a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method and the like can be employed. For example, when a solution polymerization method is employed, polymerization can be carried out by mixing monomers constituting the acrylic pressure-sensitive adhesive in a solvent and stirring at about 40 to 90 DEG C for about 2 to 10 hours. As the solvent, known ones can be used.

[Pressure Sensitive Adhesive Sheet]

The thermosensitive adhesive of the present embodiment described above can be used, for example, as a thermosensitive adhesive sheet of an inorganic material. The sheet is not limited to a sheet, and is a concept including a sheet or a film as long as the effect of the embodiment is not impaired. The thickness of the heat-sensitive adhesive sheet is preferably 1 to 500 mu m, and more preferably 5 to 300 mu m. It is preferable to laminate a release film on the surface of the thermosensitive adhesive sheet. Examples of the release film include those obtained by applying a releasing agent such as silicone to the surface of a film made of, for example, polyethylene terephthalate.

[Thermosensitive adhesive tape]

The thermosensitive pressure-sensitive adhesive of the present embodiment may be used in the form of a tape, for example, in addition to the above-described inorganic material. The thermosensitive adhesive tape according to one embodiment of the present invention comprises a base film and a pressure-sensitive adhesive layer comprising the above-mentioned thermosensitive pressure-sensitive adhesive laminated on at least one side of the base film. That is, the structure of the thermosensitive adhesive tape of this embodiment is a two-layer structure comprising a base film and a pressure-sensitive adhesive layer laminated on one side of the base film; Or a three-layer structure comprising a base film and a pressure-sensitive adhesive layer laminated on both sides of the base film.

Examples of the base film include polyethylene, polyethylene terephthalate, polypropylene, polyester, polyamide, polyimide, polycarbonate, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ethylene polypropylene copolymer, And the like.

The base film may be a single layer or a multilayer body, and the thickness thereof is usually about 5 to 500 mu m. Surface treatment such as corona discharge treatment, plasma treatment, blast treatment, chemical etching treatment and primer treatment may be performed on the surface of the base film in order to improve the adhesion to the pressure-sensitive adhesive layer.

The thickness of the pressure-sensitive adhesive layer is preferably 1 to 500 m, and more preferably 5 to 300 m.

When the thermosensitive adhesive tape of this embodiment has a three-layer structure, the pressure-sensitive adhesive layer on one side and the pressure-sensitive adhesive layer on the other side may be the same in thickness and composition or may be different.

In the case where the pressure-sensitive adhesive tape of the present embodiment has a three-layer structure, the pressure-sensitive adhesive layer on the other surface is not particularly limited as long as the pressure-sensitive adhesive layer on one side is composed of the above- Therefore, the pressure-sensitive adhesive layer on the other surface may be constituted of a pressure-sensitive adhesive layer made of, for example, a pressure-sensitive adhesive. The pressure-sensitive adhesive is a polymer having adhesiveness, and examples thereof include a natural rubber adhesive, a synthetic rubber adhesive, a styrene / butadiene latex base adhesive, and an acrylic adhesive.

As a method for producing the thermosensitive adhesive tape of the present embodiment, for example, a coating solution obtained by adding the above-mentioned thermosensitive adhesive to a solvent may be applied to the surface of the base film and dried. The application can be generally performed by a knife coater, a roll coater, a calendar coater, a comma coater, or the like. Depending on the coating thickness or the viscosity of the coating liquid, it may be performed by a gravure coater, a rod coater or the like. It is preferable that a releasing film is laminated on the surface of the pressure-sensitive adhesive layer like the pressure-sensitive adhesive sheet.

Various additives such as a crosslinking agent, a tackifier, a plasticizer, an anti-aging agent and an ultraviolet absorber may be added to the above-mentioned thermosensitive adhesive, thermosensitive adhesive sheet and thermosensitive adhesive tape. The use of the thermosensitive adhesive, the thermosensitive adhesive sheet and the thermosensitive adhesive tape can be suitably used in fields requiring ease of peeling. Examples of a member to be attached to the thermosensitive adhesive, the thermosensitive adhesive sheet and the thermosensitive adhesive tape include, for example, a touch panel body and a liquid crystal cover in a liquid crystal touch panel, a built-in organic electroluminescence (organic EL) A back-ride and a panel portion in a liquid crystal panel, and the like. However, the present invention is not limited thereto.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention can be arbitrarily made without departing from the gist of the present invention.

(Meth) acrylic acid anhydride is used as the functionalizing agent (VII), the (meth) acrylate having an isocyanato group may be used instead of the functionalizing agent (VII ) '.

When the functionalizing agent (VII) 'is used, as shown in the following reaction formula, a crystalline macromonomer represented by the general formula (II)' (hereinafter sometimes referred to as "crystalline macromonomer (II)") Can be obtained.

Wherein R ₁ and n are as defined in the general formula (I). R ₈ represents a hydrogen atom or a methyl group. and m represents an integer of 1 to 9.]

The crystalline macromonomer (II) 'is obtained by radical polymerization of a crystalline monomer (IV) containing a (meth) acrylate having at least a linear alkyl group having at least 16 carbon atoms in the presence of a chain transfer agent (V) having a hydroxyl group (VII) ', which is a (meta) acrylate having an isocyanato group at an end and a hydroxyl group at one end and having an isocyanato group, is reacted with a linear or branched alkyl group having a carbon number of 16 or more represented by R ₁ Is a macromonomer having an alkyl group and having a polymerizable double bond polymerizable at one terminal with an amorphous monomer.

Examples of the (meth) acrylate having an isocyanato group used as the functionalizing agent (VII) include 2-isocyanatoethyl (meth) acrylate and the like. As the (meth) acrylate having an isocyanato group, commercially available ones can be used. Specific examples thereof include "CALENS AOI" and "CALENS MOI" manufactured by Showa Denko Co., .

The amount of the (meth) acrylate having an isocyanato group is preferably 1.0 to 2.0 times as much as the amount of the chain transfer agent (V) having the hydroxyl group described above. In other words, the molar ratio of the (meth) acrylate having an isocyanato group to the chain transfer agent (V) having a hydroxyl group (chain transfer agent having a (meth) acrylate / hydroxyl group having an isocyanato group) To 2.0. This makes it possible to improve the reaction rate of the prepolymer (VI) with (meth) acrylate having an isocyanato group. In addition, when the side chain crystalline polymer is prepared using the obtained crystalline macromonomer (II) 'and contained in the thermosensitive pressure-sensitive adhesive, the adhesive property tends to be improved. From the viewpoint of improving the reaction rate of the prepolymer (VI) with (meth) acrylate having an isocyanato group, the above-mentioned molar ratio (chain transfer agent having a (meth) acrylate / hydroxyl group having an isocyanato group) More preferably 1.2 to 2.0, and still more preferably 1.5 to 2.0.

A catalyst may be used to accelerate the reaction rate of the prepolymer (VI) with (meth) acrylate having an isocyanato group. The amount of the catalyst to be used is preferably 10 parts by weight or less based on 100 parts by weight of the total of the prepolymer (VI) and the (meth) acrylate having an isocyanato group. As a result, the above-described reaction rate can be increased while maintaining the pot life (pot life) of the coating liquid.

Examples of the catalyst include organic tin compounds such as dibutyl tin dilaurate, organometallic compounds such as bismuth-based catalysts, and potassium-based catalysts. Commercially available catalysts can be used. Specific examples thereof include "Phuket 25", "Phuket B7" and "Phuket 15G" manufactured by Nippon Kayaku Kogyo Co., Ltd., and the like.

Hereinafter, the present invention will be described in detail with reference to Synthesis Examples and Examples, but the present invention is not limited to the following Synthesis Examples and Examples. In the following description, " parts " means parts by weight.

[Synthesis Example 1: Pressure-sensitive adhesive]

, 52 parts of ethylhexyl acrylate, 40 parts of methyl acrylate, 8 parts of hydroxyethyl acrylate and 0.2 parts of "perbutyl ND" (manufactured by Nichiyu Corporation) as a polymerization initiator were added to 200 parts of toluene, Followed by stirring for a time to polymerize these monomers. The weight average molecular weight of the obtained copolymer was 461,000.

[Synthesis Example 2: side chain crystalline polymer]

(Prepolymer)

First, 39.2 parts of behenyl acrylate, 35.3 parts of stearyl acrylate, 3.9 parts of acrylic acid as other monomers, 4.7 parts of mercaptoethanol as a chain transfer agent and 122 parts of toluene as a polymerization solvent were charged into a beaker as a crystalline monomer, At a liquid temperature of 90 占 폚 for 30 minutes. Subsequently, 0.78 part of azobisisobutyronitrile (AIBN) as a polymerization initiator was dissolved in 30 parts of toluene, and the mixture was poured into a beaker. Then, while nitrogen bubbling was performed, the mixture was stirred at a liquid temperature of 90 占 폚 for 4 hours, then the temperature of the oil bath was raised to 120 占 폚 and stirred for 2 hours to obtain a solution containing a prepolymer.

(Crystalline macromonomer)

The liquid temperature of the solution containing the prepolymer was lowered to 90 DEG C and 10.3 parts of diacrylic anhydride was added as a functionalizing agent while stirring in mixed air. The mixture was stirred for 1 hour and then 2.4 parts of water was added and stirred for 20 minutes. Next, Dean-Stark was attached to a beaker, and the temperature of the oil bath was adjusted to 120 占 폚 and stirred for 1 hour. Then, Dean Stark's water and toluene were removed from the reaction system, and then Deansstark was separated from the beaker to obtain a solution-state copolymer contained in the beaker. The weight average molecular weight and melting point of the obtained copolymer are as follows.

Weight average molecular weight: 3,900

Melting point: 55 캜

(Side chain crystalline polymer)

Subsequently, the liquid temperature was lowered to 70 占 폚, and 19.6 parts of methyl acrylate as an amorphous monomer and 5.9 parts of 1-dodecanethiol as a chain transfer agent were added, followed by nitrogen bubbling for 30 minutes. Then, 1.96 parts of "Perbutyl ND" manufactured by Nichiyu Corporation as a polymerization initiator was dissolved in 30 parts of toluene as a polymerization solvent, and the resulting mixture was stirred at a liquid temperature of 70 ° C for 4 hours, then heated to 90 ° C and stirred for 2 hours Copolymer was obtained. The weight average molecular weight and melting point of the obtained copolymer are as follows.

Weight average molecular weight: 5,540

Melting point: 52 캜

[Comparative synthesis example: side chain crystalline polymer]

40 parts of behenyl acrylate, 35 parts of stearyl acrylate, 20 parts of methyl acrylate, 5 parts of acrylic acid, 6 parts of dodecyl mercaptan as a chain transfer agent, and 10 parts of "Perhexyl PV" as a polymerization initiator Were added to 100 parts of toluene, and the mixture was stirred at 80 占 폚 for 5 hours to polymerize these monomers. The weight average molecular weight and melting point of the obtained copolymer are as follows.

Weight average molecular weight: 7,840

Melting point: 48 캜

In the above-mentioned Synthesis Examples 1 and 2 and Comparative Synthesis Examples, the weight average molecular weight is a value obtained by measuring the copolymer by GPC and converting the obtained measured value into polystyrene. The melting point was a value measured at 10 ° C / min under the measurement conditions using DSC.

[Example 1 and Comparative Example]

Sensitive adhesive tape was produced using the side chain crystalline polymer obtained in Synthesis Example 2 and Comparative Synthesis Example and the pressure-sensitive adhesive obtained in Synthesis Example 1, and the 180 ° peel strength was evaluated. The manufacturing procedure and evaluation method of the thermosensitive adhesive tape are shown below, and the results are shown in Table 1.

(Production of thermosensitive adhesive tape)

First, 3 parts of the side chain crystalline polymer obtained in Synthesis Example 2 or Comparative Synthesis Example, in terms of solid content, and 0.1 part of an isocyanate-based crosslinking agent were added to 100 parts of the copolymer solution of the pressure-sensitive adhesive obtained in Synthesis Example 1 to obtain a pressure- ≪ / RTI > Then, the obtained pressure sensitive adhesive solution was applied to one side of a polyethylene terephthalate film having a thickness of 25 占 퐉 and heated at 100 占 폚 for 10 minutes for crosslinking reaction to produce a pressure sensitive adhesive tape having a pressure sensitive adhesive layer having a thickness of 40 占 퐉. Sensitive adhesive tape using the side chain crystalline polymer obtained in Synthesis Example 2 and the heat sensitive adhesive tape using the side chain crystalline polymer obtained in Example 1 and Comparative Synthesis Example were evaluated as comparative examples.

(Evaluation of 180 ° peel strength)

The obtained pressure-sensitive adhesive tape was subjected to the initial temperature, the melting point of the side chain crystalline polymer (hereinafter sometimes referred to as " Tm ") - 10) 占 폚 and the temperature of (Tm + 10) The 180 占 peeling strength was measured according to JIS Z0237. Specifically, a thermosensitive adhesive tape was attached to a stainless steel plate at an ambient temperature of 23 占 폚, and the atmosphere temperature was adjusted to the measurement temperature. Thereafter, the thermosensitive adhesive tape was peeled off at 180 ° with a load cell at a rate of 300 mm / min. The initial temperature is 23 캜.

From the measurement value of 180 占 peeling strength at the initial temperature, the adhesive property was evaluated by the following criteria.

?: 5 N / 25 mm or more

X: less than 5N / 25 mm

(Tm-10) ° C, the adhesive property was evaluated based on the following criteria. Further, the retention ratio is a value calculated from the formula: peel strength at (Tm-10) 占 폚 / peel strength at initial temperature 占 100.

?: 3N / 25 mm or more and a retention rate of 70% or more

X: Less than 3N / 25 mm or less than 70% of retention

(Tm + 10) DEG C, the adhesive properties were evaluated based on the following criteria. Further, the rate of decrease is a value calculated from the formula: {[peeling strength at (Tm-10) 占 폚 - peeling strength at (Tm + 10) 占 폚] / peeling strength at (Tm-

?: 0.5 N / 25 mm or less and a reduction rate of 80% or more

X: more than 0.5 N / 25 mm, or less than 80%

As clearly shown in Table 1, Example 1 exhibited a higher retention rate and a higher rate of deterioration than the Comparative Example. From this result, it can be seen that in Example 1, the initial adhesive force (180 DEG peel strength at the initial temperature) can be sufficiently maintained at a temperature lower than the melting point, and the adhesive force can be sufficiently lowered at a temperature higher than the melting point .

[Synthesis Example 3: side chain crystalline polymer]

(Prepolymer)

First, 24.5 parts of behenyl acrylate, 22.1 parts of stearyl acrylate, 2.5 parts of acrylic acid as other monomers, 5.9 parts of mercaptoethanol as a chain transfer agent and 122 parts of toluene as a polymerization solvent were fed into a beaker as a crystalline monomer, At a liquid temperature of 80 占 폚 for 30 minutes. Subsequently, 0.49 parts of AIBN as a polymerization initiator was dissolved in 30 parts of toluene, and the mixture was added to a beaker. Then, the mixture was stirred at a liquid temperature of 80 캜 for 3 hours while performing nitrogen bubbling, and then the oil bath temperature was raised to 100 캜 and stirred for 2 hours to obtain a solution containing a prepolymer.

(Crystalline macromonomer)

While the liquid temperature of the solution containing the prepolymer was lowered to 80 캜 and bubbled in the mixed air, 21.3 parts of 2-isocyanatoethyl acrylate " Carens AOI ", manufactured by Showa Denko K.K., as a functionalizing agent, And 2-isocyanatoethyl acrylate were added to 1 part of dibutyl tin dilaurate and stirred for 1 hour to obtain a solution-state copolymer contained in the beaker.

The molar ratio of 2-isocyanatoethyl acrylate to mercaptoethanol (2-isocyanatoethyl acrylate / mercaptoethanol) is 2. The weight average molecular weight and melting point of the obtained copolymer and the reaction rates of the prepolymer and 2-isocyanatoethyl acrylate estimated from ¹ H-NMR are as follows.

Weight average molecular weight: 4,200

Melting point: 58 占 폚

Reaction rate: 100%

(Side chain crystalline polymer)

Subsequently, the liquid temperature was lowered to 80 DEG C, 49 parts of methyl acrylate as an amorphous monomer and 11.8 parts of 1-dodecanethiol as a chain transfer agent were added, followed by nitrogen bubbling for 30 minutes. Then, 1.37 parts of "Perbutyl ND" manufactured by Nichiyu Corporation as a polymerization initiator was dissolved in 30 parts of toluene as a polymerization solvent, and the mixture was stirred at a liquid temperature of 80 ° C for 3 hours, then heated to 100 ° C and stirred for 2 hours Copolymer was obtained. The weight average molecular weight and melting point of the obtained copolymer are as follows.

Weight average molecular weight: 9,000

Melting point: 54 캜

[Synthesis Example 4: side chain crystalline polymer]

(Prepolymer and crystalline macromonomer)

First, a solution containing a prepolymer was obtained in the same manner as in Synthesis Example 3 described above. Subsequently, in the same manner as in Synthesis Example 3, except that the addition amount of 2-isocyanatoethyl acrylate "Carensol AOI" manufactured by Showa Denko Co., Ltd., which is a functionalizing agent, was changed to 21.3 parts instead of 21.3 parts, To obtain a copolymer in a solution state.

The molar ratio of 2-isocyanatoethyl acrylate to mercaptoethanol (2-isocyanatoethyl acrylate / mercaptoethanol) is 1.5. The weight average molecular weight and melting point of the obtained copolymer and the reaction rates of the prepolymer and 2-isocyanatoethyl acrylate estimated from ¹ H-NMR are as follows.

Weight average molecular weight: 4,100

Melting point: 57 캜

Reaction rate: 100%

(Side chain crystalline polymer)

A copolymer was obtained by adding methyl acrylate as an amorphous monomer in the same manner as in Synthesis Example 3 except that the obtained copolymer was used. The weight average molecular weight and melting point of the obtained copolymer are as follows.

Weight average molecular weight: 8,900

Melting point: 54 캜

[Synthesis Example 5: side chain crystalline polymer]

(Prepolymer and crystalline macromonomer)

First, a solution containing a prepolymer was obtained in the same manner as in Synthesis Example 3 described above. Subsequently, in the same manner as in Synthesis Example 3, except that the addition amount of 2-isocyanatoethyl acrylate "Carensol AOI" manufactured by Showa Denko Co., Ltd. as the functionalizing agent was changed to 21.8 parts instead of 21.3 parts, To obtain a copolymer in a solution state.

The molar ratio of 2-isocyanatoethyl acrylate to mercaptoethanol (2-isocyanatoethyl acrylate / mercaptoethanol) is 1.2. The weight average molecular weight and melting point of the obtained copolymer and the reaction rates of the prepolymer and 2-isocyanatoethyl acrylate estimated from ¹ H-NMR are as follows.

Weight average molecular weight: 4,000

Melting point: 57 캜

Reaction rate: 72%

(Side chain crystalline polymer)

A copolymer was obtained by adding methyl acrylate as an amorphous monomer in the same manner as in Synthesis Example 3 except that the obtained copolymer was used. The weight average molecular weight and melting point of the obtained copolymer are as follows.

Weight average molecular weight: 8,500

Melting point: 55 캜

[Synthesis Example 6: side chain crystalline polymer]

(Prepolymer and crystalline macromonomer)

First, a solution containing a prepolymer was obtained in the same manner as in Synthesis Example 3 described above. Subsequently, in the same manner as in Synthesis Example 3, except that the addition amount of 2-isocyanatoethyl acrylate "Carensol AOI" manufactured by Showa Denko KK, which is a functionalizing agent, was changed to 21.3 parts instead of 21.3 parts, To obtain a copolymer in a solution state.

The molar ratio of 2-isocyanatoethyl acrylate to mercaptoethanol (2-isocyanatoethyl acrylate / mercaptoethanol) is 1. The weight average molecular weight and melting point of the obtained copolymer and the reaction rates of the prepolymer and 2-isocyanatoethyl acrylate estimated from ¹ H-NMR are as follows.

Weight average molecular weight: 4,100

Melting point: 57 캜

Reaction rate: 56%

(Side chain crystalline polymer)

A copolymer was obtained by adding methyl acrylate as an amorphous monomer in the same manner as in Synthesis Example 3 except that the obtained copolymer was used. The weight average molecular weight and melting point of the obtained copolymer are as follows.

Weight average molecular weight: 7,500

Melting point: 57 캜

[Synthesis Example 7: side chain crystalline polymer]

(Prepolymer)

First, 24.5 parts of behenyl acrylate, 22.1 parts of stearyl acrylate, 2.5 parts of acrylic acid as other monomers, 5.9 parts of mercaptoethanol as a chain transfer agent and 122 parts of toluene as a polymerization solvent were charged into a beaker as a crystalline monomer, At a liquid temperature of 90 占 폚 for 30 minutes. Subsequently, 0.49 parts of AIBN as a polymerization initiator was dissolved in 30 parts of toluene, and the mixture was added to a beaker. Then, while nitrogen bubbling was performed, the mixture was stirred at a liquid temperature of 90 占 폚 for 4 hours, then the temperature of the oil bath was raised to 120 占 폚 and stirred for 2 hours to obtain a solution containing a prepolymer.

(Crystalline macromonomer)

While the liquid temperature of the solution containing the prepolymer was lowered to 90 DEG C and bubbled in the mixed air, 12.9 parts of diacrylic anhydride was added as a functionalizing agent and stirred for 1 hour. Then, 1.5 parts of water was added and the mixture was further stirred for 20 minutes. The molar ratio of diacrylic anhydride to mercaptoethanol (diacrylic anhydride / mercaptoethanol) is 1.1.

Then, Deanstock was attached to the beaker, and the temperature of the oil bath was adjusted to 120 DEG C and the mixture was stirred for 1 hour. Then, Dean Stark's water and toluene were removed from the reaction system, and then Dean Stark was separated from the beaker to obtain a solution-state copolymer contained in the beaker. The weight average molecular weight and melting point of the obtained copolymer and the reaction rates of the prepolymer and the functionalizing agent estimated from ¹ H-NMR are as follows.

Weight average molecular weight: 3,900

Melting point: 55 캜

Reaction rate: 10%

(Side chain crystalline polymer)

Subsequently, the liquid temperature was lowered to 60 占 폚, and 49 parts of methyl acrylate as an amorphous monomer and 11.8 parts of 1-dodecanethiol as a chain transfer agent were added, followed by nitrogen bubbling for 30 minutes. Then, 1.37 parts of "Perbutyl ND" (manufactured by Nichiyu Corporation) as a polymerization initiator was dissolved in 30 parts of toluene as a polymerization solvent, and the mixture was stirred at a liquid temperature of 60 ° C for 4 hours, then heated to 90 ° C and stirred for 2 hours Copolymer was obtained. The weight average molecular weight and melting point of the obtained copolymer are as follows.

Weight average molecular weight: 5,540

Melting point: 52 캜

[Examples 2 to 6]

A pressure-sensitive adhesive tape was produced using the pressure-sensitive adhesive obtained in Synthesis Example 1 in the same manner as in Example 1 except that the side chain crystalline polymer obtained in Synthesis Examples 3 to 7 was used. Then, the 180 ° peel strength was evaluated in the same manner as in Example 1 except that the produced heat sensitive adhesive tape was used. The results are shown in Table 2.

As clearly shown in Table 2, in Examples 2 to 6, all of the retention ratios were excellent and the rate of decrease was high.

Claims (12)

A side chain crystalline polymer comprising a graft copolymer of a crystalline macromonomer and an amorphous monomer. The method according to claim 1,
The crystalline macromonomer is obtained by radical polymerization of (meth) acrylate having a straight chain alkyl group having at least 16 carbon atoms in the presence of a chain transfer agent having a hydroxyl group, and a prepolymer having a hydroxyl group at one terminal (Meth) acrylic acid anhydride or isocyanato group, which has a linear alkyl group having not less than 16 carbon atoms in the side chain and has a polymerizable double bond capable of polymerizing with the amorphous monomer at one end thereof, Macromonomer, side chain crystalline polymer. The method according to claim 1,
The crystalline macromonomer is obtained by radical polymerization of (meth) acrylate having at least a straight chain alkyl group having at least 16 carbon atoms in the presence of a chain transfer agent having a hydroxyl group, and a prepolymer having a hydroxyl group at one terminal isocyanate A macromonomer obtained by reacting a (meth) acrylate having an eutectic group and having a straight chain alkyl group having a carbon number of 16 or more on the side chain and having a polymerizable double bond polymerizable at one end with the amorphous monomer,
(Chain transfer agent having a (meth) acrylate / hydroxyl group having isocyanato group) of the (meth) acrylate having an isocyanato group and the chain transfer agent having a hydroxyl group is 1.0 to 2.0, Side chain crystalline polymer. The method according to claim 2 or 3,
(Meth) acrylate having an isocyanato group is 2-isocyanatoethyl (meth) acrylate. 5. The method according to any one of claims 1 to 4,
Wherein the crystalline macromonomer has a weight average molecular weight of 10,000 or less. 6. The method according to any one of claims 1 to 5,
Wherein the amorphous monomer is at least one selected from the group consisting of (meth) acrylate having an alkyl group having 1 to 12 carbon atoms, a polar monomer, a reactive polysiloxane compound, vinyl acetate and styrene. 6. The method according to any one of claims 1 to 5,
Wherein the amorphous monomer is a (meth) acrylate having an alkyl group having 1 to 12 carbon atoms. 6. The method according to any one of claims 1 to 5,
Wherein the amorphous monomer comprises at least methyl acrylate. 9. The method according to any one of claims 1 to 8,
Wherein the weight average molecular weight is larger than the weight average molecular weight of the crystalline macromonomer and is 20,000 or less. Sensitive adhesive comprising an acrylic pressure-sensitive adhesive and the side chain crystalline polymer according to any one of claims 1 to 9, wherein the pressure-sensitive adhesive is deteriorated at a temperature equal to or higher than the melting point of the side chain crystalline polymer. Sensitive adhesive sheet comprising the thermosensitive adhesive according to claim 10. Sensitive adhesive tape comprising a base film and a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive according to claim 10 laminated on at least one side of the base film.