WO2020004355A1

WO2020004355A1 - Adhesive sheet

Info

Publication number: WO2020004355A1
Application number: PCT/JP2019/025039
Authority: WO
Inventors: 祐介橋本; 中村　賢一; 伸幸竹谷
Original assignee: 東亞合成株式会社
Priority date: 2018-06-28
Filing date: 2019-06-25
Publication date: 2020-01-02
Also published as: JPWO2020004355A1; CN112119136A; JP7173144B2; CN112119136B

Abstract

Provided are an adhesive sheet, a decorative film having the adhesive sheet, and a decorative molding having the decorative film, the adhesive sheet having excellent adhesion to a poorly adhesive low-polarity substrate not only at room temperature but also at high temperature. Provided is an adhesive sheet characterized by having a layer including a modified polyolefin on at least one surface of an adhesive layer formed from an adhesive composition. The adhesive sheet and the decorative film provided by the present invention exhibit high adhesive force to a low-polarity material such as polypropylene, which is poorly adhesive, and can therefore be suitably used to manufacture household electric appliances, automobile interior members, and bumpers and other automobile exterior members.

Description

Adhesive sheet

The present invention relates to a pressure-sensitive adhesive sheet having a thin film layer containing a modified polyolefin as a main component, which can be used for bonding a decorative film to a difficult-to-bond member.

Adhesives (also referred to as pressure-sensitive adhesives) are processed into forms such as tapes and labels, and are used in a wide range of applications. Also, the object to be adhered is applied to various substances such as plastic, paper, metal, glass, and pottery.

粘着 Furthermore, the pressure-sensitive adhesive is used also as a decorative film for the purpose of protecting members such as home electric appliances or automotive interior / exterior articles and imparting designability. As a molding method using a decorative film, in addition to in-mold molding by injection molding, a method of pasting or transferring to a molded article by vacuum molding, vacuum pressure molding, or the like is used. Here, in the case of molding by laminating (laminating), the decorative film has a configuration in which a decorative layer and an adhesive layer are laminated on a base material layer made of a thermoplastic resin such as a vinyl chloride resin or a polyolefin resin. Is used. In the case of molding by transfer, a laminate including a protective layer, a decorative layer, and an adhesive layer is transferred to the surface of the molded body. A decorative film having such an adhesive layer is disclosed (Patent Documents 1 and 2).

On the other hand, a low-polarity material such as polypropylene is generally difficult to adhere to, and when an acrylic pressure-sensitive adhesive is applied to the low-polarity material, the adhesive strength may be insufficient. At this time, there is disclosed a method of improving the adhesive strength by mixing a styrene-based polymer and a tackifier (Patent Document 3) or a chlorinated polyolefin (Patent Documents 4 and 5) with an acrylic pressure-sensitive adhesive. In addition, a pressure-sensitive adhesive tape formed by forming a pressure-sensitive adhesive layer mainly composed of an acrylic copolymer having a higher affinity for a low-polarity adherend on the surface of the pressure-sensitive adhesive layer mainly composed of an acrylic copolymer ( Patent Document 6) and a pressure-sensitive adhesive composition capable of segregating a specific vinyl polymer having a higher glass transition point than an acrylic pressure-sensitive adhesive polymer on the surface of an acrylic pressure-sensitive adhesive polymer (Patent Document 7), It is disclosed to exhibit high adhesion.

JP 2012-213891 A JP 2012-213894 A JP 01-60677 A JP 2005-281338 A JP-A-2015-151485 JP-A-10-46115 JP 2014-88549 A

However, although the decorative films of Patent Documents 1 and 2 have good adhesion at room temperature, there is room for improvement in durability under high temperature conditions. The adherend used for the performance evaluation of the decorative film is an ABS resin, and does not mention the adhesive strength to a low-polarity base material. On the other hand, according to the methods disclosed in Patent Documents 3 to 5, although the adhesive strength at room temperature to a low-polar substrate is improved, the adhesive strength at a high temperature of about 85 to 110 ° C. is insufficient. Further, with respect to the methods disclosed in Patent Documents 6 and 7, improvement has been desired in terms of adhesion to a low-polar substrate under high-temperature conditions.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a pressure-sensitive adhesive sheet having excellent adhesiveness not only at room temperature but also at a high temperature under low-polarity substrates, and a decorative sheet having the pressure-sensitive adhesive sheet. It is to provide a film and a decorative molded article having the decorative film.

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that a specific pressure-sensitive adhesive sheet having a thin film layer containing a modified polyolefin as a main component can solve the above problems. The present invention has been completed based on this finding. The present invention provides the following means.

[1] An adhesive sheet having a layer containing a modified polyolefin on at least one surface of an adhesive layer formed from an adhesive composition.
[2] The pressure-sensitive adhesive sheet according to [1], wherein the modified polyolefin is an acid-modified polyolefin.
[3] The pressure-sensitive adhesive sheet according to [1] or [2], wherein the pressure-sensitive adhesive composition layer contains an acrylic pressure-sensitive adhesive composition.
[4] The acrylic pressure-sensitive adhesive composition contains a vinyl polymer (A) and an acrylic pressure-sensitive adhesive polymer (B), and the vinyl polymer (A) has a glass transition point (Tg) of 30 ° C. or higher. 200 ° C. or less, the number average molecular weight is 500 to 10,000, and the content is 0.5 to 60 parts by weight based on 100 parts by weight of the acrylic pressure-sensitive adhesive polymer (B). When the acrylic pressure-sensitive adhesive composition is applied to a separator and dried to obtain a pressure-sensitive adhesive composition layer, the first Tg, which is the Tg of the entire pressure-sensitive adhesive composition layer, is −80 ° C. or more and 10 ° C. Wherein the second Tg, which is the Tg calculated from the surface layer portion obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive composition layer, is higher by 30 ° C. or more than the first Tg. The pressure-sensitive adhesive sheet according to [3].
[5] the adhesive composition contains an acrylic adhesive polymer (B), and the thin film layer mainly containing a modified polyolefin contains an acrylic adhesive polymer (B); [1] The pressure-sensitive adhesive sheet according to any one of to [4].
[6] The method for producing a pressure-sensitive adhesive sheet according to any one of [1] to [5], wherein a layer containing a modified polyolefin is formed on a release film.
[7] The method for producing a pressure-sensitive adhesive sheet according to any one of [1] to [5], wherein a layer containing the modified polyolefin is formed, and then the pressure-sensitive adhesive composition is laminated on the layer. A method for producing a pressure-sensitive adhesive sheet, comprising forming a layer containing the modified polyolefin on the surface of a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition by coating.
[8] A decorative film having the pressure-sensitive adhesive sheet according to any one of [1] to [5].
[9] A decorative molded product obtained by sticking the decorative film according to [8] to the molded product.

According to the present invention, it is possible to provide a pressure-sensitive adhesive sheet having excellent adhesion to a low-polar substrate not only at room temperature but also at high temperature.

Hereinafter, the present invention will be described in detail. In this specification, “(meth) acryl” means acryl and / or methacryl, and “(meth) acrylate” means acrylate and / or methacrylate. Further, “(meth) acryloyl group” means an acryloyl group and / or a methacryloyl group.

According to the present invention, there is provided a pressure-sensitive adhesive sheet having a layer containing a modified polyolefin on at least one surface of a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition. That is, there is provided a pressure-sensitive adhesive sheet having a layer containing a modified polyolefin on one or both surfaces of the pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition, on the entire surface or a part of the surface. Further, a decorative film having the pressure-sensitive adhesive sheet and a decorative molded article having the decorative film are provided.
Hereinafter, the pressure-sensitive adhesive layer, the modified polyolefin, the pressure-sensitive adhesive sheet, the decorative film, and the decorative molded article formed from the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive sheet provided by the present invention will be described.

<About the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition>
The thickness of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition used in the present invention is appropriately selected depending on the type and purpose of use of the pressure-sensitive adhesive composition, and is not particularly limited. For example, the average value of the entire layer is 2 to 200 μm, for example, 15 to 100 μm, and for example, 20 to 70 μm.

The type of the pressure-sensitive adhesive composition used in the present invention is not particularly limited as long as it satisfies the required performance according to the application such as tackiness, heat resistance, durability, and chemical resistance. Products, polyester-based pressure-sensitive adhesive compositions, urethane-based pressure-sensitive adhesive compositions, silicone-based pressure-sensitive adhesive compositions, rubber-based pressure-sensitive adhesive compositions, and the like. Among these, an acrylic pressure-sensitive adhesive composition is preferred from the viewpoint of transparency and the like.

In the acrylic pressure-sensitive adhesive composition, the acrylic pressure-sensitive adhesive polymer (B) is preferably 60% by weight or more, more preferably 70% by weight or more, and still more preferably 80% by weight, based on the total amount of the acrylic pressure-sensitive adhesive composition. %, More preferably 90% by weight or more. The acrylic adhesive polymer (B) is a polymer containing (meth) acrylic acid esters as main constituent units. The Tg of the acrylic adhesive polymer (B) is preferably −80 to 10 ° C., more preferably −50 ° C. to 10 ° C., still more preferably −30 ° C. to 0 ° C., and still more preferably -20 ° C to 0 ° C. When the Tg is -80 ° C or higher, the cohesive force of the obtained pressure-sensitive adhesive layer is high, which is preferable. Further, when Tg is −30 ° C. or higher, heat resistance tends to be good, which is more preferable. When the Tg is 10 ° C. or lower, the adhesive strength at a low temperature is good, which is preferable.

Further, the acrylic adhesive polymer (B) preferably has a weight average molecular weight (Mw) of 100,000 or more from the viewpoint of exhibiting sufficient cohesive force and good adhesiveness. It is more preferably at least 250,000, and still more preferably at least 400,000. Further, it is preferable that the weight average molecular weight (Mw) is 600,000 or more in that heat resistance is further improved, and for example, it can be 700,000 or more, for example, 800,000 or more. On the other hand, in consideration of ease of handling in production, the upper limit is preferably 2,000,000 or less. More preferably, it is 1,500,000 or less, and still more preferably, it is 1,000,000 or less.

The monomer constituting the acrylic adhesive polymer (B) is an alkyl (meth) acrylate having an alkyl group having 4 to 12 carbon atoms in that an acrylic copolymer having low Tg and adhesiveness can be obtained. Examples thereof include esters and alkoxyalkyl (meth) acrylates having an alkoxyalkyl group having 2 to 12 carbon atoms, and one or more of these can be used.

Examples of the alkyl (meth) acrylate having an alkyl group having 4 to 12 carbon atoms include n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, (meth) N-octyl acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, (meth) Lauryl acrylate and the like can be mentioned, and preferable monomers are n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, (meth) acrylate ) N-nonyl acrylate, isononyl (meth) acrylate and the like.

Examples of the alkoxyalkyl (meth) acrylate having an alkoxyalkyl group having 2 to 12 carbon atoms include methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, butoxymethyl (meth) acrylate, and (meth) acrylate. ) Methoxyethyl acrylate, ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, ethoxybutyl (meth) acrylate, butoxybutyl (meth) acrylate, and the like, Methoxyethyl (meth) acrylate is preferred.

The amount of the (meth) acrylic acid alkyl ester having an alkyl group having 4 to 12 carbon atoms and / or the (meth) acrylic acid alkoxyalkyl ester having an alkoxyalkyl group having 2 to 12 carbon atoms depends on the amount of the acrylic adhesive polymer ( It is preferably from 30 to 100% by weight, more preferably from 50 to 99% by weight, based on all the constituent monomers of B). When the content is 30% by weight or more, the resulting adhesive composition has high adhesive strength, initial adhesive strength (tack), low-temperature adhesiveness, and the like.

In addition, among the above-mentioned monomers, a low-molecular-weight vinyl polymer (A) as a tackifier described later in the pressure-sensitive adhesive composition tends to segregate to the surface layer of the pressure-sensitive adhesive composition while exhibiting good pressure-sensitive adhesive performance. It is more preferable to use (meth) acrylic acid alkoxyalkyl ester. The amount of the (meth) acrylic acid alkoxyalkyl ester to be used is preferably at least 40% by weight, more preferably at least 45% by weight, based on all the constituent monomers of the acrylic adhesive polymer (B). , More preferably at least 50% by weight. Further, it is preferably at least 60% by weight, more preferably at least 70% by weight. The upper limit of the amount of the alkoxyalkyl (meth) acrylate used is 100% by weight.

When an alkyl (meth) acrylate having an alkyl group having 1 to 3 carbon atoms is used as a constituent monomer of the acrylic adhesive polymer (B), the heat resistance of the acrylic adhesive polymer (B) is improved. Preferred. In the pressure-sensitive adhesive composition, a low-molecular-weight vinyl polymer (A) as a tackifier described later is preferably segregated to the surface layer of the pressure-sensitive adhesive composition, and thus preferably has an alkyl (meth) acrylate having 1 to 2 carbon atoms. Esters, more preferably methyl (meth) acrylate, can be used. The amount of the alkyl (meth) acrylate having an alkyl group having 1 to 3 carbon atoms is 0 to 90% by weight, preferably 0 to 80% by weight, as a monomer unit constituting the acrylic adhesive polymer (B). %, More preferably 0 to 70% by weight, and even more preferably 0 to 60% by weight.

The acrylic pressure-sensitive adhesive polymer (B) is, besides the above-mentioned alkyl (meth) acrylate and alkoxyalkyl (meth) acrylate, other monomers copolymerizable therewith as long as the tackiness is not impaired. The body can be used.

Other copolymerizable monomers include, for example, α, β-unsaturated carboxylic acid monomers such as (meth) acrylic acid, itaconic acid, maleic acid and fumaric acid; styrene, α-methylstyrene, vinyl Aromatic vinyl monomers such as toluene; cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate Aliphatic monocyclic esters of unsaturated dicarboxylic acids such as monoethyl itaconate and monobutyl fumarate; 2-hydroxyethyl (meth) acrylate, 3- (meth) acrylate Hydroxypropyl, 4-hydroxybutyl (meth) acrylate, polyethylene glycol (meth Hydroxyl-containing monomers such as acrylate, polypropylene glycol (meth) acrylate and polyethylene-polypropylene glycol mono (meth) acrylate; ethylenically unsaturated such as acrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, N-methoxybutylacrylamide Carboxylic acid amides and N-substituted compounds; unsaturated alcohols such as allyl alcohol; (meth) acrylonitrile, vinyl acetate, glycidyl (meth) acrylate, and diacetone acrylamide; Can be used.

In addition, a polyfunctional polymerizable monomer having two or more polymerizable functional groups such as a (meth) acryloyl group and an alkenyl group in the molecule may be used.

Examples of the polyfunctional (meth) acrylate compound include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and polypropylene glycol di ( Di (meth) acrylates of dihydric alcohols such as meth) acrylate; trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide modified tri (meth) acrylate, glycerin tri (meth) acrylate, pentaerythritol tri ( Poly (meth) acrylates such as tri (meth) acrylate and tetra (meth) acrylate of trihydric or higher polyhydric alcohols such as meth) acrylate and pentaerythritol tetra (meth) acrylate And the like can be given Relate.

Examples of the polyfunctional alkenyl compound include polyfunctional allyl ether compounds such as trimethylolpropane diallyl ether, pentaerythritol diallyl ether, pentaerythritol triallyl ether, tetraallyloxyethane, and polyallyl saccharose; polyfunctional allyl compounds such as diallyl phthalate; Bisamides such as bisacrylamide and hydroxyethylene bisacrylamide; and polyfunctional vinyl compounds such as divinylbenzene can be exemplified.

Examples of the compound having both the (meth) acryloyl group and the alkenyl group include allyl (meth) acrylate, isopropenyl (meth) acrylate, butenyl (meth) acrylate, pentenyl (meth) acrylate, and (meth) acrylic acid. 2- (2-vinyloxyethoxy) ethyl and the like can be mentioned.

The acrylic adhesive polymer (B) is not particularly limited in its production method. For example, the above monomer may be prepared by employing a known radical polymerization method such as a solution polymerization method, a suspension polymerization method, or an emulsion polymerization method. Can be easily obtained by polymerizing In the case of the solution polymerization method, an organic solvent and an acrylic monomer raw material are charged into a reactor, a thermal polymerization initiator such as an organic peroxide and an azo compound is added, and the mixture is heated to 50 to 300 ° C. to copolymerize. By doing so, the desired acrylic adhesive polymer (B) can be obtained. The acrylic adhesive polymer (B) may be used as a solution dissolved in an organic solvent, or may be used after distilling off the solvent by heating under reduced pressure.

The method of charging each raw material including a monomer may be a batch-type initial batch charging in which all raw materials are charged collectively, or a semi-continuous charging in which at least one raw material is continuously supplied into a reactor, A continuous polymerization system in which the raw materials are continuously supplied and the produced resin is simultaneously continuously withdrawn from the reactor may be used.

Examples of the organic solvent used in the solution polymerization method include cyclic ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbon compounds such as benzene, toluene and xylene, esters such as ethyl acetate and butyl acetate, acetone, methyl ethyl ketone and cyclohexanone. Examples thereof include ketones and other alcohols such as methyl orthoformate, methyl orthoacetate, methanol, ethanol and isopropanol, and one or more of these can be used. Among these organic solvents, preferred are ethyl acetate, butyl acetate, acetone, and methyl ethyl ketone which have a relatively low boiling point so that the acrylic adhesive polymer (B) can be well dissolved and easily purified.

開始 As the initiator to be used, an azo compound, an organic peroxide, an inorganic peroxide or the like can be used, but it is not particularly limited. A known redox-type polymerization initiator composed of an oxidizing agent and a reducing agent may be used. Further, a known chain transfer agent can be used in combination.

Examples of the azo compound include 2,2′-azobis (isobutyronitrile), 1,1-azobis (cyclohexane-1-carbonitrile), azocumene, and 2,2′-azobis (2-methylbutyronitrile) ), 2,2'-azobisdimethylvaleronitrile, 4,4'-azobis (4-cyanovaleric acid), 2- (tert-butylazo) -2-cyanopropane, 2,2'-azobis (2,4 , 4-trimethylpentane), 2,2'-azobis (2-methylpropane), dimethyl 2,2'-azobis (2-methylpropionate) and the like.

Examples of the organic peroxide include cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane 1,1-bis (tert-butylperoxy) cyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, cumene hydroperoxide, 2,5-dimethylhexane-2,5-di Hydroperoxide, 1,3-bis [(tert-butylperoxy) -m-isopropyl] benzene, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, diisopropylbenzene peroxide, tert -Butylcumyl peroxide , Decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, bis (tert-butylcyclohexyl) peroxydicarbonate, tert-butylperoxybenzoate, 2,5-dimethyl-2, 5-di (benzoylperoxy) hexane and the like.

Examples of the inorganic peroxide include potassium persulfate, sodium persulfate, and ammonium persulfate.

Examples of the redox type polymerization initiator include sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, ferrous sulfate and the like as reducing agents, potassium peroxodisulfate, hydrogen peroxide, tert-butyl hydroperoxide. Those using an oxide or the like as an oxidizing agent can be used.

As the acrylic adhesive polymer (B), commercially available products may be used, such as SK Dyne 2950, 2953, and 2943H manufactured by Soken Chemical Co., Ltd., or Nippon Synthetic Chemical Co., Inc. 8711, N-2411TF, etc. Can be exemplified.

<About acrylic block copolymer>
The acrylic adhesive polymer (B) may include an acrylic block copolymer (hereinafter, referred to as “the present block copolymer”). The block copolymer need only have at least one polymer block (a) and at least one (meth) acrylic polymer block (b). For example, the m polymer block (a) and the (meth) acrylic block (Ab) a diblock composed of a polymer block (b), a (aba) triblock composed of a polymer block (a) / (meth) acrylic polymer block (b) / polymer block (a), Alternatively, a (block) triblock composed of a polymer block (b) / (meth) acrylic polymer block (a) / polymer block (b) and the like can be mentioned. Further, it may have a structure such as (abc) or (abca) including a polymer block (c) other than the polymer block (a) and the (meth) acrylic polymer block (b). Among them, the block copolymer preferably has an a- (ba) n (n is an integer of 1 or more) structure. With such a structure, the polymer block (a) forms a pseudo-crosslinked structure, which is preferable from the viewpoint of adhesive properties. The a- (ba) n structure may be present in all or a part of the copolymer, and may be, for example, a copolymer having a (babab) structure.
Here, regarding the glass transition point of the present block copolymer, an inflection point corresponding to each polymer block is obtained by performing differential scanning calorimetry, and the Tg of each polymer block can be determined from these. it can. In the present invention, the Tg of the present block copolymer means the Tg of a polymer block as a main component.

(Polymer block (a))
The polymer block (a) of the present block copolymer may be a block having a monomer derived from one or both of a maleimide compound and an amide group-containing vinyl compound as a constitutional unit.

The maleimide compound includes a maleimide and an N-substituted maleimide compound. Examples of the N-substituted maleimide compound include N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, N-isopropylmaleimide, Nn-butylmaleimide, N-isobutylmaleimide, N-tert-butylmaleimide N-alkyl-substituted maleimide compounds such as N-pentylmaleimide, N-hexylmaleimide, N-heptylmaleimide, N-octylmaleimide, N-laurylmaleimide and N-stearylmaleimide; N-cyclopentylmaleimide and N-cyclohexylmaleimide N-cycloalkyl-substituted maleimide compounds; N-phenylmaleimide, N- (4-hydroxyphenyl) maleimide, N- (4-acetylphenyl) maleimide, N- (4-methoxyphenyl) maleimide, N- (4- N-aryl-substituted maleimide compounds such as toxicphenyl) maleimide, N- (4-chlorophenyl) maleimide, N- (4-bromophenyl) maleimide, and N-benzylmaleimide, and one or two of these. The above can be used. By polymerizing a monomer containing a maleimide compound, a structural unit derived from the maleimide compound can be introduced into the polymer block (a). In the polymer block (a), a compound represented by the following general formula (1) is preferred among the above, from the viewpoint that the heat resistance and adhesiveness of the obtained block copolymer become more excellent.

In the formula, R ¹ represents hydrogen, an alkyl group having 1 to 3 carbon atoms, or PhR ² . Here, Ph represents a phenyl group, and R ² represents hydrogen, a hydroxy group, an alkoxy group having 1 to 2 carbon atoms, an acetyl group or a halogen. ｝

Examples of the amide group-containing vinyl compound include, for example, (meth) acrylamide, tert-butyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide (Meth) acrylamide derivatives such as N, N, N-dimethylaminopropyl (meth) acrylamide and (meth) acryloylmorpholine; N-vinylamide monomers such as N-vinylacetamide, N-vinylformamide and N-vinylisobutylamide And the like, and one or more of these can be used. By polymerizing a monomer containing an amide group-containing vinyl compound, a structural unit derived from the amide group-containing vinyl compound can be introduced into the polymer block (a).

(4) The structural units derived from the maleimide compound and the amide group-containing vinyl compound can be 10% by mass or more and 100% by mass or less based on all the structural units of the polymer block (a). Such constituent units are, for example, 15% by mass or more, for example, 20% by mass or more, for example, 30% by mass or more, for example, 40% by mass or more, for example, 50% by mass or more, For example, it is 60% by mass or more. It is, for example, 99% by mass or less, for example, 90% by mass or less, for example, 80% by mass or less, for example, 75% by mass or less, and for example, 70% by mass or less.

When the structural unit derived from the maleimide compound and the amide group-containing vinyl compound is less than 10% by mass, the resulting block copolymer may not have sufficient heat resistance, durability and peeling resistance.

The polymer block (a) may be a block having a monomer derived from styrenes as a structural unit. Styrenes include styrene and its derivatives. Specific compounds include, for example, styrene, α-methylstyrene, β-methylstyrene, vinyltoluene, vinylxylene, vinylnaphthalene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, pn-butylstyrene, p-isobutylstyrene, pt-butylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-chloromethylstyrene, p-chloromethylstyrene, o-chlorostyrene, p-chlorostyrene, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, divinylbenzene, etc., and one or more of these are used. be able to. By polymerizing a monomer containing styrenes, a structural unit derived from styrenes can be introduced into the polymer block (a).

でも Of the above, styrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-hydroxystyrene, m-hydroxystyrene, and p-hydroxystyrene are preferable from the viewpoint of polymerizability. Further, α-methylstyrene, β-methylstyrene, and vinylnaphthalene are preferable in that the glass transition point (Tg) of the polymer block (a) can be increased and a block having excellent heat resistance can be obtained.

(4) Structural units derived from styrenes can be 1% by mass to 70% by mass with respect to all the structural units of the polymer block (a). Such a constituent unit is, for example, 5% by mass or more, for example, 10% by mass or more, and for example, 20% by mass or more. It is, for example, 60% by mass or less, for example, 50% by mass or less, and for example, 40% by mass or less.

(4) When the amount of the structural unit derived from styrenes is 1% by mass or more, the polymerizability of the maleimide compound can be particularly improved. On the other hand, when the content is 70% by mass or less, the required amount of the structural unit derived from the maleimide compound and the amide group-containing vinyl compound can be secured, so that the block copolymer is excellent in heat resistance, durability, and peeling resistance. Can be obtained.

重合 Moreover, the polymer block (a) can be a block containing a structural unit derived from a vinyl monomer having a crosslinkable functional group (hereinafter, also simply referred to as a crosslinkable structural unit). The crosslinkable structural unit may be introduced using, for example, a maleimide compound having a functional group such as a hydroxy group and / or an amide group-containing vinyl compound, or by copolymerizing a vinyl compound having a crosslinkable functional group. Can also be introduced.

The vinyl monomer having a crosslinkable functional group is not particularly limited, and various known monomer compounds can be used. For example, unsaturated carboxylic acids, unsaturated acid anhydrides, and hydroxy group-containing vinyl compounds , An epoxy group-containing vinyl compound, a primary or secondary amino group-containing vinyl compound, a reactive silicon group-containing vinyl compound, an oxazoline group-containing vinyl compound, and an isocyanate group-containing vinyl compound. In the polymer block (a), known compounds can be used alone or in combination of two or more.

Examples of unsaturated carboxylic acids include (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, cinnamic acid, and monoalkyl esters of unsaturated dicarboxylic acids (maleic acid, fumaric acid, itacone Acids, citraconic acid, maleic anhydride, itaconic anhydride, monoalkyl esters such as citraconic anhydride) and the like. These compounds may be used alone or in combination of two or more.

Examples of the unsaturated acid anhydride include maleic anhydride, itaconic anhydride, citraconic anhydride and the like. These compounds may be used alone or in combination of two or more.

Examples of the hydroxy group-containing vinyl compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and (meth) acrylate. ) 3-hydroxybutyl acrylate, 4-hydroxybutyl (meth) acrylate, and mono (meth) acrylates of polyalkylene glycols such as polyethylene glycol and polypropylene glycol. These compounds may be used alone or in combination of two or more.

Examples of the epoxy group-containing vinyl compound include glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth) acrylate. These compounds may be used alone or in combination of two or more.

Examples of the vinyl compound containing a primary or secondary amino group include amino groups such as aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, N-methylaminoethyl (meth) acrylate, and N-ethylaminoethyl (meth) acrylate. Containing (meth) acrylic acid ester; amino group-containing (meth) acrylamide such as aminoethyl (meth) acrylamide, aminopropyl (meth) acrylamide, N-methylaminoethyl (meth) acrylamide, N-ethylaminoethyl (meth) acrylamide And the like.

Examples of the reactive silicon group-containing vinyl compound include vinylsilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, and vinyldimethylmethoxysilane; trimethoxysilylpropyl (meth) acrylate, (meth) acrylic acid Silyl group-containing (meth) acrylates such as triethoxysilylpropyl, methyldimethoxysilylpropyl (meth) acrylate and dimethylmethoxysilylpropyl (meth) acrylate; silyl group-containing vinyl ethers such as trimethoxysilylpropyl vinyl ether; Examples thereof include silyl group-containing vinyl esters such as vinyl trimethoxysilylundecanoate. These compounds may be used alone or in combination of two or more. A reactive silicon group-containing vinyl compound is preferable because two or more crosslinkable functional groups can be easily introduced. Further, in such a vinyl compound, reactive silicon groups can be dehydrated and condensed (polymerized). For this reason, it is suitable in that the polymerization reaction for producing the block copolymer and the subsequent crosslinking reaction can be efficiently performed.

外 In addition to the above, an oxazoline group or an isocyanate group can be introduced as a crosslinkable functional group by copolymerizing an oxazoline group-containing vinyl compound or an isocyanate group-containing vinyl compound.

Furthermore, a polymerizable unsaturated group is introduced as a crosslinkable functional group into the polymer block (a) by copolymerizing a polyfunctional polymerizable monomer having two or more polymerizable unsaturated groups in the molecule. obtain. The polyfunctional polymerizable monomer is a compound having two or more polymerizable functional groups such as a (meth) acryloyl group and an alkenyl group in a molecule, and is a polyfunctional (meth) acrylate compound, a polyfunctional alkenyl compound, A compound having both a (meth) acryloyl group and an alkenyl group is exemplified. For example, in addition to alkylene diol diacrylates such as hexanediol diacrylate, allyl (meth) acrylate, isopropenyl (meth) acrylate, butenyl (meth) acrylate, pentenyl (meth) acrylate, and (meth) acrylic acid 2 Compounds having both (meth) acryloyl and alkenyl groups in the molecule, such as-(2-vinyloxyethoxy) ethyl, are exemplified. These compounds may be used alone or in combination of two or more.

In the case where the polymer block (a) has a crosslinkable structural unit, for example, the polymer block (a) may have a crosslinkable structural unit in an amount of 0.01 mol% or more based on all the structural units. Further, it is, for example, 0.1 mol% or more, for example, 1.0 mol% or more, and for example, 2.0 mol% or more. By providing the crosslinkable structural unit in an amount of 0.01 mol% or more, a good crosslinked structure can be easily obtained, and a block copolymer having high heat resistance and durability can be easily obtained. Although the upper limit is not particularly limited, it is, for example, 60 mol% or less, for example, 40 mol% or less, and for example, 20 mol% or less, and for example, 10 mol% or less from the viewpoint of controllability of the crosslinking reaction. Mol% or less. The range of the crosslinkable structural unit can be appropriately combined with the lower limit and the upper limit described above. For example, 1 mol% or more and 60 mol% or less, for example, 5 mol% or more and 50 mol% or less, 10 mol% or more and 40 mol % Or less.

The polymer block (a) may also include a structural unit derived from another monomer copolymerizable with these monomers, as long as the function of the present block copolymer is not impaired. For example, (meth) acrylic acid alkyl ester compounds, (meth) acrylic acid alkoxyalkyl ester compounds, and the like can be included. These compounds may be used alone or in combination of two or more.

Examples of the alkyl (meth) acrylate compound include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-propyl (meth) acrylate, and n- (meth) acrylate. Butyl, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, Linear or branched alkyl ester compounds of (meth) acrylic acid such as n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate and dodecyl (meth) acrylate; (meth) Cyclohexyl acrylate, methylcyclohexyl (meth) acrylate, (meth) Such as tert-butylcyclohexyl acrylate, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentanyl (meth) acrylate Examples thereof include aliphatic cyclic ester compounds of (meth) acrylic acid.

Examples of the alkoxyalkyl (meth) acrylate compound include methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, and n- (meth) acrylate. -Propoxyethyl, n-butoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, ethoxypropyl (meth) acrylate, n-propoxypropyl (meth) acrylate, n-butoxypropyl (meth) acrylate, Examples include methoxybutyl (meth) acrylate, ethoxybutyl (meth) acrylate, n-propoxybutyl (meth) acrylate, and n-butoxybutyl (meth) acrylate.

単量体 Other monomers other than those described above include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate and the like.

In the polymer block (a), the ratio occupied by the structural units derived from the other monomers is, for example, in the range of 0% by mass to 50% by mass with respect to all the structural units of the polymer block (a). It can be. In addition, for example, it is 5% by mass or more, and for example, 10% by mass or more. It is, for example, 45% by mass or less, and for example, 40% by mass or less.

(Glass transition point)
The glass transition point (Tg) of the polymer block (a) is 100 ° C. or higher. The Tg of the polymer block (a) can contribute to the heat resistance of the present block copolymer. Therefore, when Tg is 100 ° C. or higher, good heat resistance can be imparted to the present block copolymer. It is, for example, 120 ° C. or higher, for example, 140 ° C. or higher, for example, 160 ° C. or higher, for example, 180 ° C. or higher, for example, 190 ° C. or higher, and, for example, 200 ° C. or higher. Further, Tg is preferably 350 ° C. or lower due to the limitation of usable constituent monomer units. The temperature is, for example, 280 ° C. or lower, for example, 270 ° C. or lower, and, for example, 260 ° C. or lower.

In the present specification, the glass transition point of the block copolymer in addition to the polymer block (a) and the (meth) acrylic polymer block (b) is determined by differential scanning calorimetry as described in Examples described later. (DSC). When DSC is not possible, it can be determined by calculation from the monomer units constituting the polymer block.

(Phase separation)
The polymer block (a) preferably has the property of phase-separating from the (meth) acrylic polymer block (b). By having such properties, a microphase-separated structure can be formed. Those skilled in the art can easily design a block that is phase-separated from the (meth) acrylic polymer block (b) based on the technical common sense at the time of filing the present application. For example, the difference between the SP value calculated by a known method for calculating a solubility parameter, for example, the SP value calculated by the Fedors method shown below and the SP value of the (meth) acrylic polymer block (b) is 0.01 (absolute value). ) And above. Also, for example, it may be 0.05 or more, for example, 0.1 or more, or for example, 0.2 or more. Further, for example, it may be 0.5 or more. Further, for example, a polymer blend of the intended polymer block (a) and the (meth) acrylic polymer block (b) is prepared, and the structure obtained by mixing these is blended with an electron microscope, an atomic force microscope, or a small angle X. By observing by line scattering or the like, the phase separation between the blocks can be easily estimated.

The SP value is R.P. F. It can be calculated by the calculation method described in “Polymer Engineering and Science” written by Fedors, 14 (2), 147 (1974). Specifically, the calculation is performed according to the calculation method shown in Expression (1).

δ: SP value ((cal / cm ^{3) 1/2} )
ΔEvap: molar evaporation heat of each atomic group (cal / mol)
V: molar volume of each atomic group (cm ³ / mol)

((Meth) acrylic polymer block (b))
The (meth) acrylic polymer block (b) of the present block copolymer can be a block having at least one structural unit selected from the compounds represented by the general formula (2). Examples of the compound represented by the general formula (2) include an alkyl (meth) acrylate, an alkoxyalkyl (meth) acrylate, and a polyalkylene glycol mono (meth) acrylate.
CH ₂ ＣＲCR ¹ -C (＝ O) O (R ² O) _n -R ³ (2)
(Wherein, R ¹ represents hydrogen or a methyl group, R ² represents a linear or branched alkylene group having 2 to 6 carbon atoms, and R ³ represents hydrogen, an alkyl group having 1 to 20 carbon atoms, or a carbon atom having 1 to 20 carbon atoms. Represents an aryl group of 6 to 20. n represents 0 or an integer of 1 to 100.)

Examples of the alkyl (meth) acrylate and the alkoxyalkyl (meth) acrylate include the alkyl (meth) acrylate and the alkoxyalkyl (meth) acrylate that can be used for the polymer block (a). it can.

As the polyalkylene glycol mono (meth) acrylate, (R ² O) in the general formula (2) may be only one type, or may include two or more types of structural units. When two or more kinds of (R ² O) are present, n represents the sum of the number of repeating units of each structural unit. n may be 1 to 100, 1 to 50, or 1 to 30. Specific compounds include polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol-polypropylene glycol mono (meth) acrylate, polyethylene glycol-polytetraethylene glycol mono (meth) acrylate, and methoxy polyethylene glycol. Mono (meth) acrylate, lauroxy polyethylene glycol mono (meth) acrylate, stearoxy polyethylene glycol mono (meth) acrylate, octoxy polyethylene glycol-polypropylene glycol mono (meth) acrylate, phenoxy polyethylene glycol mono (meth) acrylate, phenoxy polyethylene Glycol-polypropylene glycol mono (meth) acryl Over DOO, nonyl phenoxy polyethylene glycol mono (meth) acrylate, nonylphenoxy polypropylene glycol mono (meth) acrylate, nonylphenoxy polyethylene glycol - and polypropylene glycol mono (meth) acrylate. The above compound is also available as a commercial product. Examples of the methoxypolyethylene glycol monomethacrylate include “Blemmer PME series” (n = 2, 4, 9, 23, 90, etc., and Blemmer is a registered trademark).
In addition, a (meth) acrylate compound having a functional group such as an amide group, an amino group, a carboxy group, or a hydroxy group can also be used.

In the (meth) acrylic polymer block (b), among the above, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 2 to 8 carbon atoms is preferable in that a block copolymer having excellent flexibility is obtained. An alkyl acrylate compound having an alkyl group is preferred. Further, in consideration of the adhesive performance, the acrylic monomer preferably contains an alkyl acrylate compound having an alkyl group having 1 to 8 carbon atoms or an alkoxyalkyl group having 2 to 3 carbon atoms. preferable.

構成 The structural unit derived from the compound represented by the general formula (2) can be 20% by mass or more and 100% by mass or less with respect to all the structural units of the (meth) acrylic polymer block (b). Such a constituent unit is, for example, 50% by mass or more and 100% by mass or less, for example, 80% by mass or more and 100% by mass or less, and for example, 90% by mass or more and 100% by mass or less. When the above-mentioned constitutional unit is in the above-mentioned range, there is a tendency that a block copolymer having good adhesive properties is obtained. When the content of the structural unit is 50% by mass or more, the (meth) acrylic polymer block (b) contains at least one selected from the compounds represented by the general formula (2) as a main constituent monomer. Block.

（The (meth) acrylic polymer block (b) can be a block containing a crosslinkable structural unit. The crosslinkable structural unit can be introduced, for example, by copolymerizing a vinyl compound having a crosslinkable functional group.

When the (meth) acrylic polymer block (b) has a crosslinkable structural unit, for example, 0.01 mol% of the crosslinkable structural unit to all the structural units of the (meth) acrylic polymer block (b). The above can be provided. It is, for example, 0.1 mol% or more, and for example, 0.5 mol% or more. When the introduction amount of the crosslinkable structural unit is 0.01 mol% or more, it becomes easy to obtain a block copolymer having excellent heat resistance. The upper limit is not particularly limited, but is, for example, 20 mol% or less, for example, 10 mol% or less, and, for example, 5 mol% or less from the viewpoint of flexibility. The range of the crosslinkable structural unit can be appropriately combined with the lower limit and the upper limit described above. For example, 0.01 mol% or more and 20 mol% or less, for example, 0.1 mol% or more and 10 mol% or less, and 0.1 mol% or less. 5 mol% or more and 5 mol% or less.

As long as the effects exerted by the present disclosure are not hindered, the (meth) acrylic polymer block (b) uses a monomer other than the (meth) acrylic monomer as a constituent monomer unit. Can be. As the monomer other than the (meth) acrylic monomer, a monomer having an unsaturated group other than the (meth) acryloyl group can be used, and aliphatic monomers such as alkyl vinyl esters, alkyl vinyl ethers, and styrenes can be used. Or an aromatic vinyl compound.

(Glass transition point)
The glass transition point (Tg) of the (meth) acrylic polymer block (b) is 10 ° C. or less. The Tg of the (meth) acrylic polymer block (b) can contribute to the tackiness of the present block copolymer. Therefore, when Tg is 10 ° C. or less, good tackiness can be imparted to the present block copolymer. It is also, for example, 0 ° C. or lower, for example, −5 ° C. or lower, for example, −10 ° C. or lower, for example, −20 ° C. or lower, for example, −25 ° C. or lower, and for example, −30 ° C. or lower. And, for example, −35 ° C. or less.

(Phase separation)
As described above, the (meth) acrylic polymer block (b) preferably has a property of phase-separating from the polymer block (a), and a predetermined difference from the SP value of the polymer block (a) is determined. It is preferred to have.

This block copolymer is not particularly limited as long as a block copolymer having a polymer block (a) and a (meth) acrylic polymer block (b) is obtained, and a known production method is employed. can do. For example, a method using various control polymerization methods such as living radical polymerization and living anion polymerization, a method of coupling polymers having a functional group, and the like can be used. Among these, the living radical polymerization method is preferred from the viewpoint that the operation is simple and can be applied to a wide range of monomers.

There is no particular limitation on the type of living radical polymerization method, and reversible addition-fragmentation chain transfer polymerization method (RAFT method), nitroxy radical method (NMP method), atom transfer radical polymerization method (ATRP method), organic tellurium compound , A polymerization method using an organic antimony compound (SBRP method), a polymerization method using an organic bismuth compound (BIRP method), and an iodine transfer polymerization method. Among these, the RAFT method, the NMP method, and the ATRP method are preferred from the viewpoint of controllability of polymerization and easiness of implementation.

In the RAFT method, controlled polymerization proceeds via a reversible chain transfer reaction in the presence of a specific polymerization controller (RAFT agent) and a general free radical polymerization initiator. As the RAFT agent, various known RAFT agents such as dithioester compounds, xanthate compounds, trithiocarbonate compounds, and dithiocarbamate compounds can be used. As the RAFT agent, a monofunctional agent having only one active site may be used, or a bifunctional or higher functional agent may be used. From the viewpoint that the block copolymer having the a- (ba) n-type structure can be obtained efficiently, it is preferable to use a bifunctional RAFT agent. The amount of the RAFT agent used is appropriately adjusted depending on the type of the monomer and the RAFT agent to be used.

Known radical polymerization initiators such as azo compounds, organic peroxides and persulfates can be used as the polymerization initiator used in the polymerization by the RAFT method. An azo compound is preferable in that a side reaction hardly occurs. Specific examples of the azo compound include those described above. The radical polymerization initiator may be used alone or in combination of two or more.

The use ratio of the radical polymerization initiator is not particularly limited, but from the viewpoint of obtaining a polymer having a smaller molecular weight distribution, the amount of the radical polymerization initiator to be used is preferably 0.5 mol or less per 1 mol of the RAFT agent. .2 mol or less is more preferable. Further, from the viewpoint of stably performing the polymerization reaction, the lower limit of the amount of the radical polymerization initiator to be used per 1 mol of the RAFT agent is 0.01 mol. Therefore, the amount of the radical polymerization initiator used per 1 mol of the RAFT agent is preferably in the range of 0.01 to 0.5 mol, and more preferably in the range of 0.05 to 0.2 mol.

The reaction temperature at the time of the polymerization reaction by the RAFT method is preferably from 40 ° C to 100 ° C, more preferably from 45 ° C to 90 ° C, and further preferably from 50 ° C to 80 ° C. When the reaction temperature is at least 40 ° C., the polymerization reaction can proceed smoothly. On the other hand, when the reaction temperature is 100 ° C. or lower, side reactions can be suppressed, and restrictions on the initiator and the solvent that can be used are relaxed.

In the NMP method, a specific alkoxyamine compound having a nitroxide is used as a living radical polymerization initiator, and polymerization proceeds via a nitroxide radical derived therefrom. In the production of the block copolymer used in the present invention, the type of nitroxide radical used is not particularly limited, and a commercially available nitroxide-based polymerization initiator can be used. Further, from the viewpoint of controllability of polymerization when a monomer containing an acrylate is polymerized, it is preferable to use a compound represented by the general formula (3) as a nitroxide compound.

In the formula, R ¹ is an alkyl group having 1 to 2 carbon atoms or a hydrogen atom, R ² is an alkyl group having 1 to 2 carbon atoms or a nitrile group, and R ³ is — (CH ₂ ) m-, m Is from 0 to 2, and R ⁴ and R ⁵ are an alkyl group having 1 to 4 carbon atoms. ｝

ニトロ The nitroxide compound represented by the general formula (3) is primarily dissociated by heating at about 70 to 80 ° C., and causes an addition reaction with the vinyl monomer. At this time, a polyfunctional polymerization precursor can be obtained by adding a nitroxide compound to a vinyl monomer having two or more vinyl groups. Then, the vinyl monomer can be subjected to living polymerization by secondary dissociation of the polymerization precursor under heating. In this case, since the polymerization precursor has two or more active sites in the molecule, a polymer having a narrower molecular weight distribution can be obtained. From the viewpoint of efficiently obtaining the block copolymer having the a- (ba) n-type structure, it is preferable to use a bifunctional polymerization precursor having two active sites in the molecule. The amount of the nitroxide compound to be used is appropriately adjusted depending on the type of the monomer and the nitroxide compound used.

When the present block copolymer is produced by the NMP method, the nitroxide radical represented by the following general formula (4) is added to the nitroxide compound represented by the following general formula (3) in an amount of 0.001 to 0.2 mol per 1 mol of the nitroxide compound represented by the above general formula (3). Polymerization may be carried out by adding in the range.

In the formula, R ⁶ and R ⁷ are an alkyl group having 1 to 4 carbon atoms. ｝

By adding 0.001 mol or more of the nitroxide radical represented by the general formula (4), the time required for the concentration of the nitroxide radical to reach a steady state is reduced. As a result, the polymerization can be controlled to a higher degree, and a polymer having a narrower molecular weight distribution can be obtained. On the other hand, if the amount of the nitroxide radical is too large, polymerization may not proceed. A more preferable addition amount of the nitroxide radical per 1 mol of the nitroxide compound is in a range of 0.01 to 0.5 mol, and a more preferable addition amount is 0.05 to 0.5 mol.
It is in the range of 0.2 mol.

The reaction temperature in the NMP method is preferably from 50 ° C to 140 ° C, more preferably from 60 ° C to 130 ° C, further preferably from 70 ° C to 120 ° C, particularly preferably from 80 ° C to 120 ° C. It is as follows. When the reaction temperature is 50 ° C. or higher, the polymerization reaction can proceed smoothly. On the other hand, when the reaction temperature is 140 ° C. or lower, side reactions such as radical chain transfer tend to be suppressed.

In the ATRP method, a polymerization reaction is generally performed using an organic halide as an initiator and a transition metal complex as a catalyst. As the organic halide as the initiator, a monofunctional one or a bifunctional or higher one may be used. It is preferable to use a bifunctional compound from the viewpoint that the block copolymer having the a- (ba) n-type structure can be efficiently obtained. Further, as the kind of halogen, bromide and chloride are preferable.

The reaction temperature in the ATRP method is preferably from 20 ° C to 200 ° C, more preferably from 50 ° C to 150 ° C. When the reaction temperature is 20 ° C. or higher, the polymerization reaction can proceed smoothly.

An a- (ba) n-type structure such as an aba triblock copolymer composed of a polymer block (a)-(meth) acrylic polymer block (b) -polymer block (a) by a living radical polymerization method When a polymer is obtained, for example, the desired block copolymer may be obtained by sequentially polymerizing each block. In this case, first, as a first polymerization step, a polymer block (a) is obtained using the constituent monomers of the polymer block (a). Next, as a second polymerization step, a (meth) acrylic polymer block (b) is obtained using the constituent monomers of the (meth) acrylic polymer block (b). Further, as the third polymerization step, an aba triblock copolymer can be obtained by performing polymerization using the constituent monomers of the polymer block (a). In this case, it is preferable to use the above-mentioned monofunctional polymerization initiator or polymerization precursor as the polymerization initiator. By repeating the second polymerization step and the third polymerization step, a higher-order block copolymer such as a pentablock copolymer can be obtained.

場合 In addition, it is preferable to produce the target product more efficiently by a method including the following two-stage polymerization step, because the target product can be obtained more efficiently. That is, in the first polymerization step, after the (meth) acrylic polymer block (b) is obtained using the constituent monomers of the (meth) acrylic polymer block (b), the polymerizing step is performed in the second polymerization step. The constituent monomer of the united block (a) is polymerized to obtain a polymer block (a). Thereby, an aba triblock copolymer consisting of the polymer block (a)-(meth) acrylic polymer block (b) -polymer block (a) can be obtained. In this case, it is preferable to use a bifunctional polymerization initiator or a polymerization precursor as the polymerization initiator. According to this method, the process can be simplified as compared with a case where each block is sequentially polymerized and manufactured. Further, by repeating the first polymerization step and the second polymerization step, a higher-order block copolymer such as a tetrablock copolymer can be obtained.

重合 The polymerization of the block copolymer used in the present invention may be carried out in the presence of a chain transfer agent, if necessary, regardless of the polymerization method. As the chain transfer agent, known ones can be used. Specifically, ethanethiol, 1-propanethiol, 2-propanethiol, 1-butanethiol, 2-butanethiol, 1-hexanethiol, 2-hexane Thiol, 2-methylheptane-2-thiol, 2-butylbutane-1-thiol, 1,1-dimethyl-1-pentanethiol, 1-octanethiol, 2-octanethiol, 1-decanethiol, 3-decanethiol, 1-undecanethiol, 1-dodecanethiol, 2-dodecanethiol, 1-tridecanethiol, 1-tetradecanethiol, 3-methyl-3-undecanethiol, 5-ethyl-5-decanethiol, tert-tetradecanethiol, -Hexadecanethiol, 1-heptadecanethiol and 1- In addition to alkylthiol compounds having an alkyl group having 2 to 20 carbon atoms, such as kutadecanethiol, mercaptoacetic acid, mercaptopropionic acid, 2-mercaptoethanol, etc., may be used, and one or more of these may be used. Can be.

製造 In the production of the block copolymer used in the present invention, a known polymerization solvent for living radical polymerization can be used. Specifically, aromatic compounds such as benzene, toluene, xylene, and anisole; ester compounds such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; ketone compounds such as acetone and methyl ethyl ketone; dimethylformamide, acetonitrile, dimethyl sulfoxide; Alcohol, water and the like. Further, the polymerization may be carried out in a mode such as bulk polymerization without using a polymerization solvent.

他 In addition, the acrylic adhesive polymer (B) can be obtained from an acrylic adhesive polymer syrup. In this case, the acrylic adhesive polymer syrup contains a polymer component that is a part of the acrylic adhesive polymer (B) and a (meth) acrylic monomer that constitutes the balance of the acrylic adhesive polymer (B). can do. By applying energy such as heat or active energy rays to the acrylic adhesive polymer syrup and polymerizing the monomer components contained in the syrup, an acrylic adhesive polymer (B) is obtained.

The acrylic pressure-sensitive adhesive composition may use a tackifier for improving the adhesive strength in addition to the acrylic pressure-sensitive adhesive polymer (B).
The tackifier is not particularly limited as long as it is solid at normal temperature, and examples thereof include a rosin compound, a terpene compound, a petroleum resin compound, and a low molecular weight vinyl polymer (A).

These tackifiers may be used alone or in combination of two or more. Among these tackifiers, it is preferable to use a low molecular weight vinyl polymer (A) from the viewpoint of peel strength under high temperature conditions, transparency and the like.

低 In the present invention, the low molecular weight vinyl polymer (A) that can be used as a tackifier is preferably a polymer having a Tg of 20 to 200 ° C. A preferred lower limit of Tg is 30 ° C. or higher, more preferably 50 ° C. or higher, still more preferably 60 ° C. or higher, and further preferably 70 ° C. or higher. The upper limit of Tg may be 180 ° C. or lower, 150 ° C. or lower, 120 ° C. or lower, or 110 ° C. or lower. In this specification, a value measured at a heating rate of 10 ° C./min by differential scanning calorimetry (DSC) is adopted as Tg. When the Tg is 20 ° C. or higher, the Tg of the surface layer of the pressure-sensitive adhesive layer becomes sufficiently high, and the adhesive strength to various adherends increases. Also, Tg generally does not exceed 200 ° C. due to restrictions on the raw material monomers.

As the monomer constituting the low molecular weight vinyl polymer (A), various vinyl compounds having radical polymerizability can be used. For example, (meth) acrylic acid compounds, aromatic vinyl compounds, Saturated carboxylic acid, unsaturated acid anhydride, hydroxyl group-containing unsaturated compound, amino group-containing unsaturated compound, amide group-containing unsaturated compound, alkoxyl group-containing unsaturated compound, cyano group-containing unsaturated compound, nitrile group-containing unsaturated compound And a maleimide-based compound. These compounds may be used alone or in combination of two or more.

中でも Among these, it is preferable to use a (meth) acrylic acid-based compound as the main component, since appropriate compatibility with the acrylic pressure-sensitive adhesive polymer (B) can be obtained. The specific amount of the (meth) acrylic acid-based compound used is preferably in the range of 10 to 100% by weight based on all the constituent monomer units of the low molecular weight vinyl polymer (A). More preferably, it is 30 to 100% by weight, and still more preferably 50 to 100% by weight.

Examples of the (meth) acrylic acid-based compound include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) acrylate. , Isobutyl (meth) acrylate, tert-butyl (meth) acrylate, amyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, ethylhexyl (meth) acrylate, ( Alkyl (meth) acrylates such as n-dodecyl (meth) acrylate and n-octadecyl (meth) acrylate; cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, tert-butyl (meth) acrylate Cyclohexyl, cyclododecyl (meth) acrylate, i-methacrylate Bornyl, (meth) adamantyl acrylate, (meth) acrylic acid dicyclopentenyl include aliphatic rings vinyl monomers such as (meth) dicyclopentanyl acrylate. These compounds may be used alone or in combination of two or more.

Among these, (meth) acrylic acid is preferred because Tg can be set relatively high, the effect of suppressing the lifting and peeling of the pressure-sensitive adhesive sheet is high, and the adhesion to the olefin-based adherend is good. It is preferable to use aliphatic cyclic vinyl monomers such as isobornyl, dicyclopentanyl (meth) acrylate, cyclohexyl (meth) acrylate and adamantyl (meth) acrylate. The specific amount of the aliphatic cyclic vinyl monomer used is preferably in the range of 10 to 90% by weight, more preferably 20 to 80% by weight, based on all the constituent monomer units of the low molecular weight vinyl polymer (A). Is more preferable, and 20 to 70% by weight is more preferable.

Examples of the aromatic vinyl compound include aromatic ring-based vinyl compounds such as phenyl (meth) acrylate and benzyl (meth) acrylate, styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, and vinyltoluene. , Β-methylstyrene, ethylstyrene, p-tert-butylstyrene, vinylxylene, vinylnaphthalene and the like. These compounds may be used alone or in combination of two or more. The specific amount of the aromatic vinyl compound used is preferably in the range of 0 to 40% by weight, more preferably 1 to 30% by weight, based on all the constituent monomer units of the low molecular weight vinyl polymer (A). 5-20% by weight is more preferred.

Examples of the unsaturated carboxylic acids include (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid and monoalkyl esters of unsaturated dicarboxylic acids (maleic acid, fumaric acid, itaconic acid). And monoalkyl esters such as citraconic acid, maleic anhydride, itaconic anhydride and citraconic anhydride). These compounds may be used alone or in combination of two or more.

Examples of the hydroxyl group-containing unsaturated compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate Mono (meth) acrylates of polyalkylene glycols such as 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol or polypropylene glycol, p-hydroxystyrene, m-hydroxystyrene , O-hydroxystyrene, p-isopropenylphenol, m-isopropenylphenol, o-isopropenylphenol and the like. These compounds may be used alone or in combination of two or more.

Examples of the amino group-containing unsaturated compound include dimethylaminomethyl (meth) acrylate, diethylaminomethyl (meth) acrylate, 2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, ( 2- (di-n-propylamino) ethyl (meth) acrylate, 2-dimethylaminopropyl (meth) acrylate, 2-diethylaminopropyl (meth) acrylate, 2- (di-n-propyl) (meth) acrylate Amino) propyl, 3-dimethylaminopropyl (meth) acrylate, 3-diethylaminopropyl (meth) acrylate, 3- (di-n-propylamino) propyl (meth) acrylate and the like. These compounds may be used alone or in combination of two or more.

Examples of the amide group-containing unsaturated compound include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamidotyl (meth) acrylamide, N, N-dimethylaminopropyl (Meth) acrylamide, N-methylol (meth) acrylamide and the like. These compounds may be used alone or in combination of two or more.

Examples of the unsaturated compound having an alkoxyl group include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (n-propoxy) ethyl (meth) acrylate, and (meth) acrylic acid. 2- (n-butoxy) ethyl, 3-methoxypropyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, 2- (n-propoxy) propyl (meth) acrylate, 2- (meth) acrylate (N-butoxy) propyl and the like. These compounds may be used alone or in combination of two or more.

Examples of the cyano group-containing unsaturated compound include cyanomethyl (meth) acrylate, 1-cyanoethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, 1-cyanopropyl (meth) acrylate, and (meth) acrylic acid. 2-cyanopropyl acrylate, 3-cyanopropyl (meth) acrylate, 4-cyanobutyl (meth) acrylate, 6-cyanohexyl (meth) acrylate, 2-ethyl-6-cyanohexyl (meth) acrylate, ( 8-cyanooctyl meth) acrylate and the like. These compounds may be used alone or in combination of two or more.

Examples of the unsaturated compound having a penitrile group include (meth) acrylonitrile, ethacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-chloroacrylonitrile, α-fluoroacrylonitrile, and the like. These compounds may be used alone or in combination of two or more.

Examples of the maleimide compound include maleimide, N-methylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-dodecylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N- (2-methylphenyl) maleimide, Examples include N- (4-methylphenyl) maleimide, N- (2,6-dimethylphenyl) maleimide, N- (2,6-diethylphenyl) maleimide, N-benzylmaleimide, N-naphthylmaleimide, and the like. These compounds may be used alone or in combination of two or more.

以外 In addition to the above compounds, dialkyl esters of unsaturated dicarboxylic acids, vinyl ester compounds, vinyl ether compounds and the like can also be used. Examples of the dialkyl ester of an unsaturated dicarboxylic acid include dialkyl esters such as maleic acid, fumaric acid, itaconic acid, citraconic acid, maleic anhydride, itaconic anhydride and citraconic anhydride. Examples of the vinyl ester compound include methylene aliphatic monocarboxylic acid ester, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl butyrate, vinyl benzoate, vinyl formate, vinyl cinnamate and the like. Examples of the vinyl ether compound include vinyl methyl ether, vinyl ethyl ether, vinyl-n-butyl ether, vinyl isobutyl ether, vinyl phenyl ether, and vinyl cyclohexyl ether.

The number average molecular weight (Mn) of the low molecular weight vinyl polymer (A) can be 500 to 30,000. It is preferably from 600 to 20,000, more preferably from 800 to 10,000, and still more preferably from 1,000 to 5,000. If Mn is 30,000 or less, the compatibility with the acrylic adhesive polymer (B) becomes appropriate. On the other hand, when Mn is 500 or more, the productivity of the low molecular weight vinyl polymer (A) is high.

比 Further, the ratio (Mw / Mn) between the weight average molecular weight (Mw) and the above (Mn) is preferably 3.0 or less from the viewpoint that good adhesive strength is easily obtained. It is more preferably at most 2.5, further preferably at most 2.0, even more preferably at most 1.8. The weight average molecular weight Mw and the number average molecular weight Mn are values in terms of standard polystyrene obtained by using gel permeation chromatography (GPC).

The low-molecular-weight vinyl polymer (A) can be obtained by a known radical polymerization method such as a solution polymerization method, a suspension polymerization method, or an emulsion polymerization method described with respect to the method for producing the acrylic adhesive polymer (B). .

The low-molecular-weight vinyl polymer (A) can also be obtained by continuous polymerization in a temperature range of 180 to 350 ° C. using a stirred tank reactor. In this polymerization method, a polymer having a high purity can be obtained because a polymer having a relatively low molecular weight can be obtained without substantially using a polymerization initiator or a chain transfer agent, which is advantageous in terms of coloring and odor. It is preferable because there is. When the polymerization temperature is 180 ° C. or higher, the polymerization reaction does not require a polymerization initiator or a large amount of a chain transfer agent, and the obtained copolymer has less coloring and odor. On the other hand, when the polymerization temperature is 350 ° C. or less, since the side reaction during the polymerization reaction is small and the obtained copolymer is little colored, the pressure-sensitive adhesive composition layer obtained from the pressure-sensitive adhesive composition layer containing the same is transparent. High in nature. Further, according to such a polymerization method, a polymer having a small molecular weight distribution range can be obtained. The polymerization initiator may be optionally used, but is preferably used at 1% by weight or less based on all monomers.

[Tg of the entire pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition when the acrylic pressure-sensitive adhesive polymer (B) and the low-molecular-weight vinyl polymer (A) are used together (first Tg)]
The Tg of the entire pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, that is, the first Tg, can be in a range of −80 ° C. or more and 10 ° C. or less. The lower limit of Tg may be −70 ° C. or higher, −60 ° C. or higher, −50 ° C. or higher, or −40 ° C. or higher. The upper limit of Tg may be 0 ° C or lower, -10 ° C or lower, -20 ° C or lower, or -30 ° C or lower. The upper limit and the lower limit of Tg can be appropriately combined with each other. For example, Tg is in the range of −70 ° C. to 0 ° C., and is, for example, −60 ° C. to −10 ° C., and It is 50 ° C. or higher and −20 ° C. or lower. When the first Tg is -80 ° C or higher, the cohesive strength of the obtained pressure-sensitive adhesive layer tends to be high, and when the first Tg is 10 ° C or lower, the adhesive force under low-temperature conditions tends to be high. The Tg of the present pressure-sensitive adhesive composition layer can be obtained by DSC at a temperature rising rate of 10 ° C./min and a nitrogen atmosphere as a measurement atmosphere.

[Tg (second Tg) calculated from the composition of the surface layer portion of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition when the acrylic pressure-sensitive adhesive polymer (B) and the low molecular weight vinyl polymer (A) are used in combination. ]
The second Tg of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, that is, when the pressure-sensitive adhesive layer is obtained by applying the pressure-sensitive adhesive composition to a separator and then drying or irradiating with an active energy ray, The Tg calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy of the agent composition layer is the vinyl polymer (A) obtained from X-ray photoelectron spectroscopy (XPS) and the acrylic adhesive polymer (B). ) Can be obtained by calculation from the composition ratio, and can be regarded as Tg of the composition forming the surface layer from the surface of the pressure-sensitive adhesive layer to a depth of about 5 nm. The details of the measurement method can be in accordance with the operations described in Examples described later.

The second Tg is not particularly limited, but is preferably 0 ° C. or higher. The second Tg is 0
When the temperature is higher than or equal to ° C., the Tg difference described below is easily obtained, and as a result, the high-temperature adhesion and durability of the adherend can be ensured. The second Tg is more preferably at least 10 ° C, further preferably at least 30 ° C, still more preferably at least 40 ° C, more preferably at least 50 ° C, still more preferably at least 60 ° C. . Note that the second Tg can be appropriately adjusted by the Tg of the vinyl polymer (A), the compounding ratio, and the like.

[Tg of the entire pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (first Tg) and Tg calculated from the composition of the surface layer portion of the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition (second Tg) difference〕
In the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, the second Tg (Tg calculated from the composition of the surface layer portion of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition) is the first Tg (the above-described Tg). It is preferable that the temperature be 30 ° C. or higher than Tg) of the entire pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. According to the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition having such a Tg composition, the higher the temperature of the pressure-sensitive adhesive layer of the conventional general pressure-sensitive adhesive, the lower the adhesiveness, whereas the higher the pressure, the higher the temperature. High adhesiveness can be exhibited.

Further, when the second Tg is higher than the first Tg by 30 ° C. or more, the decorative film including the pressure-sensitive adhesive composition layer formed from the pressure-sensitive adhesive composition has a curved surface or an uneven portion. It is possible to follow a complicated shape having. Further, for example, even when the film base material shrinks under high-temperature conditions, the resulting poor appearance such as displacement, peeling or floating is suppressed, and excellent durability is exhibited.

The second Tg is preferably 40 ° C. or higher, more preferably 50 ° C. or higher, still more preferably 60 ° C. or higher, more preferably 65 ° C. or higher, and 70 ° C. or higher than the first Tg. More preferred. The upper limit of the height of the second Tg with respect to the first Tg is not particularly limited, but is 280 ° C. from the possible values of the first Tg and the second Tg, and is generally 200 ° C. It is as follows.

[Weight fraction of vinyl polymer (A) to total weight of vinyl polymer (A) and acrylic pressure-sensitive adhesive polymer (B) in surface layer of pressure-sensitive adhesive layer formed from pressure-sensitive adhesive composition (A / A + B)]
In the measurement of the second Tg, the surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition is subjected to composition analysis by X-ray photoelectron spectroscopy. At this time, the weight of the vinyl polymer (A) in the surface is measured. The fraction can be determined. This weight fraction can be used as an index of the segregation state of the vinyl polymer (A) in the surface layer portion of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition.

For example, the weight fraction is preferably 55% or more and 95% or less. Within this range, segregation of the vinyl polymer (A) to the surface layer portion occurs, so that curved surface adhesiveness and durability can be obtained even at high temperature or high temperature and high humidity. It is more preferably at least 60%, further preferably at least 65%, still more preferably at least 70%, still more preferably at least 75%, even more preferably at least 80%. Further, the weight fraction is preferably 90% or less, more preferably 85% or less.

Among the tackifiers other than the low molecular weight vinyl polymer (A), examples of the rosin-based compound include a disproportionated rosin ester resin, a hydrogenated rosin ester resin, and a polymerized rosin ester resin. These may be commercially available products. Examples of the disproportionated rosin ester resin include Arakawa Chemical Industries' superesters A-100, A-115, and A-125. Examples of the hydrogenated rosin ester resin include Pine Crystal KE-604 and KE-140 manufactured by Arakawa Chemical Industries. Examples of the polymerized rosin ester resin include Pencel A, Pencel C, Pencel D-125, Pencel D-135, and Pencel D-160 manufactured by Arakawa Chemical Industries.
Commercially available terpene compounds include, for example, Tamanol 80L and Tamanol 901 manufactured by Arakawa Chemical Industry Co., Ltd., or YS Polyster G150, YS Polystar G125, YS Polystar T100, YS Polystar T115, YS Polystar T130 manufactured by Yashara Chemical Company. , And YS polystar T145.
Commercially available petroleum resin compounds include, for example, FTR-6100, FTR-6125, and FTR-7125 manufactured by Mitsui Chemicals.

The amount of the tackifier used is preferably 0 to 40% by weight, more preferably 0 to 30% by weight, based on the amount of the acrylic adhesive polymer (B) used in the present invention. Preferably it is 0 to 20% by weight. When the amount used is within the above range, the balance between the effect of improving the adhesiveness and the heat resistance becomes good.

粘着 The pressure-sensitive adhesive composition used in the present invention can contain a crosslinking agent. The crosslinking agent is not necessarily required, but its addition is considered depending on the intended adhesive properties and the form of the adhesive composition, for example, whether it is an emulsion form or a solution form. By containing a cross-linking agent, the cohesive force and the adhesive force of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition are adjusted, and further, at a high temperature, or at high temperature and high humidity, and adhesion to a curved surface. Or can be given. Examples of the crosslinking agent include an epoxy compound having two or more epoxy groups, an isocyanate compound having two or more isocyanate groups, an aziridine compound having two or more aziridinyl groups, an oxazoline compound having an oxazoline group, a metal chelate compound, and a butylated melamine compound. And the like. Among these, it is preferable to use an aziridine compound, an epoxy compound and an isocyanate compound.

Examples of the aziridine compound include 1,6-bis (1-aziridinylcarbonylamino) hexane, 1,1 ′-(methylene-di-p-phenylene) bis-3,3-aziridyl urea, and 1,1 ′ -(Hexamethylene) bis-3,3-aziridyl urea, ethylene bis- (2-aziridinyl propionate), tris (1-aziridinyl) phosphine oxide, 2,4,6-triaziridinyl-1,3,5 -Triazine, trimethylolpropane-tris- (2-aziridinylpropionate) and the like.

Examples of the epoxy compound include bisphenol A epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin diglycidyl ether, and neopentyl glycol diglycidyl. Ether, 1,6-hexanediol diglycidyl ether, diglycidylaniline, tetraglycidylxylenediamine, N, N, N ', N'-tetraglycidyl- m- xylylenediamine, 1,3-bis (N, N- Diglycidylaminomethyl) cyclohexane, trimethylolpropane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol Polyglycidyl ethers, polyfunctional glycidyl compounds such as sorbitol polyglycidyl ether.

化合物 As the isocyanate compound, a compound having two or more isocyanate groups is preferably used. As the above-mentioned isocyanate compound, various aromatic, aliphatic and alicyclic isocyanate compounds, and modified products of these isocyanate compounds (prepolymers and the like) can be used.

Examples of the aromatic isocyanate include diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene diisocyanate (NDI), p-phenylene diisocyanate (PPDI), xylene diisocyanate (XDI), and tetramethyl xylylene diisocyanate (TMXDI). And tolidine diisocyanate (TODI). Examples of the aliphatic isocyanate include hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI), and lysine triisocyanate (LTI). Examples of the alicyclic isocyanate include isophorone diisocyanate (IPDI), cyclohexyl diisocyanate (CHDI), hydrogenated XDI (H6XDI), and hydrogenated MDI (H12MDI). Examples of the modified isocyanate include urethane-modified, dimer, trimer, carbodiimide-modified, allophanate-modified, burette-modified, urea-modified, isocyanurate-modified, oxazolidone-modified isocyanate compounds of the above-mentioned isocyanate compounds. Base-terminated prepolymers and the like can be mentioned.

(4) The content of the crosslinking agent can be preferably 0.01 to 10 parts by weight based on 100 parts by weight of the acrylic adhesive polymer (B). A more preferred lower limit is 0.03 parts by weight or more, and still more preferably 0.05 parts by weight or more. Further, a more preferable upper limit is 5 parts by weight or less, further preferably 2 parts by weight or less. Further, a more preferable range is from 0.03 to 5 parts by weight, and a more preferable range is from 0.05 to 2 parts by weight.

The pressure-sensitive adhesive composition used in the present invention includes, as long as the effects of the present invention are not impaired, other components such as a plasticizer, an antioxidant, an ultraviolet absorber, an antioxidant, a flame retardant, a fungicide, and a silane. Additives such as a coupling agent, a filler and a coloring agent can be blended. The amount of the additive is preferably 0 to 10% by weight, more preferably 0 to 5% by weight, and still more preferably the amount of the acrylic adhesive polymer (B) used in the present invention. Is from 0 to 2% by weight.

<About modified polyolefin>
The modified polyolefin which is a component of the pressure-sensitive adhesive sheet provided by the present invention is obtained by modifying a polyolefin by chemical modification. The thickness of the layer containing the modified polyolefin is appropriately selected according to the type and additive of the modified polyolefin or the purpose of use, and is not particularly limited. The average value of the entire layer is, for example, 0.05 to 50 μm, for example, 0.1 to 15 μm, and for example, 0.5 to 5 μm.

Examples of polyolefin include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-heptene, 4- Α-olefins having 2 to 20 carbon atoms such as methyl-1-hexene, 1-octene, 4,4-dimethyl-1-hexene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, and butadiene And conjugated or non-conjugated dienes having 2 to 20 carbon atoms, such as 1,5-hexadiene, ethylidene norbornene and dicyclopentadiene. Further, an ethylene / ethyl acrylate copolymer, an ethylene / vinyl acetate copolymer, a styrene / butadiene copolymer, a styrene / isoprene copolymer, or the like may be used. When a copolymer is used, a random copolymer, a block copolymer, and a graft copolymer can be appropriately selected. These polyolefins may be used in combination of two or more.

Preferred examples of the polyolefin include polypropylene, propylene / ethylene copolymer, propylene / 1-butene copolymer, propylene / ethylene / 1-butene copolymer, and propylene / ethylene / 1-octene copolymer. it can. When a propylene copolymer is used, the propylene content is preferably 50% by weight or more, more preferably 60% by weight or more, and further preferably 75% by weight or more.

変性 Examples of the type of modified polyolefin used in the present invention include acid-modified polyolefin, chlorinated polyolefin, carbodiimide-modified polyolefin, urea-modified polyolefin, and imine-modified polyolefin. These modifications may be those in which two or more kinds of modifications are sequentially performed, and examples thereof include acid-modified chlorinated polyolefin, acryl-modified chlorinated polyolefin, and urethane-modified chlorinated polyolefin. Among these, acid-modified polyolefin, chlorinated polyolefin, and acid-modified chlorinated polyolefin can be suitably used, and acid-modified polyolefin is particularly preferable.

The acid-modified polyolefin can be prepared by graft copolymerizing an unsaturated carboxylic acid or an anhydride thereof with the polyolefin. Conventionally known methods can be used for the modification reaction, for example, a method in which an unsaturated carboxylic acid or an anhydride thereof is added to a molten polyolefin using an extruder to copolymerize the polyolefin, or a method in which a polyolefin dissolved in a solvent is used. Examples thereof include a method in which a saturated carboxylic acid or an anhydride thereof is added and copolymerized, a method in which an unsaturated carboxylic acid or an anhydride thereof is added to a water-suspended polyolefin and copolymerized. The polyolefin chain may be modified at this modification at one or both ends of the molecular chain, in the middle of the molecular chain, or at multiple positions.

Unsaturated carboxylic acids or anhydrides that can be used in the above modification reaction include unsaturated monocarboxylic acids such as (meth) acrylic acid, crotonic acid, isocrotonic acid, and cinnamic acid, fumaric acid, maleic acid, citraconic acid, and chloromaleic acid. Unsaturated dicarboxylic acids such as acid, glutaconic acid, and itaconic acid; half esters or half amides of these unsaturated dicarboxylic acids; unsaturated tricarboxylic acids such as trans-anicotic acid; maleic anhydride; citraconic anhydride; Acid anhydrides such as maleic anhydride, itaconic anhydride and 3,4,5,6-tetrahydrophthalic anhydride are exemplified. Among these, (meth) acrylic acid, maleic acid and maleic anhydride are preferred, and maleic anhydride is particularly preferred.

The graft weight of maleic anhydride or the like in the acid-modified polyolefin is preferably 0.1 to 20% by weight, more preferably 0.5 to 10% by weight, when the entire acid-modified polyolefin is 100% by weight. . When the graft weight is within this range, the layer containing the modified polyolefin can exhibit high adhesion to both the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition and a low-polarity material such as polypropylene.

The acid-modified polyolefin may be modified by using another modifier together with the modification reaction with the unsaturated carboxylic acid or its anhydride. Other modifiers include (meth) acrylic acid alkyl esters, functional group-containing (meth) acrylic acid alkyl esters, aromatic vinyl compounds, cyclohexyl vinyl ether, and the like.

As the alkyl (meth) acrylate, specifically, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, Hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, ( Examples thereof include cyclohexyl (meth) acrylate. These compounds may be used alone or in combination of two or more. In the present invention, it is preferable to use a modifier further containing a (meth) acrylate having an alkyl group having 8 to 18 carbon atoms, since the heat resistance is improved. In particular, octyl (meth) acrylate, It is preferable to contain lauryl (meth) acrylate, tridecyl (meth) acrylate or stearyl (meth) acrylate.

Examples of the functional group-containing alkyl (meth) acrylate include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, and isocyanate-containing (meth) acrylate. Examples of the aromatic vinyl compound include benzyl (meth) acrylate, styrene, o-methylstyrene, p-methylstyrene, α-methylstyrene, and the like. By using an unsaturated carboxylic acid or its anhydride and another modifier in combination as the modifier, it is possible to improve the graft ratio by the modifier and further improve the adhesiveness.

グラフト The graft weight of the modified polyolefin by another modifier is preferably 0.1 to 20% by weight, more preferably 0.5 to 10% by weight, assuming that the entire acid-modified polyolefin is 100% by weight. When the graft weight is within this range, the graft ratio by a modifier such as maleic anhydride is improved, or the layer containing the modified polyolefin to the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition exhibits high adhesion. be able to. The graft weight can be determined by a known method such as Fourier transform infrared spectroscopy.

(4) The weight average molecular weight of the modified polyolefin is preferably from 3,000 to 500,000, more preferably from 25,000 to 250,000. When the weight-average molecular weight of the acid-modified polyolefin resin is 3,000 or more, heat resistance is good, and when it is 500,000 or less, solubility in a solvent is improved and handleability is excellent.

The modified polyolefin preferably has a melting point of 50 ° C. or higher from the viewpoint of heat resistance, more preferably has a melting point of 70 ° C. or higher, and still more preferably has a melting point of 85 ° C. or higher. On the other hand, if the melting point is too high, the wettability to the adherend is inferior.

In the present invention, instead of the acid-modified polyolefin, a copolymer having a carboxylic acid and / or acid anhydride structure incorporated in the basic skeleton of the polyolefin may be used. For example, ethylene / acrylic acid / maleic anhydride may be used. A terpolymer of an acid or the like may be used.

As the modified polyolefin, a commercially available product may be used, and those used for a plastic surface modifier, a primer for an automotive plastic substrate, a primer for an electronic substrate, a primer for a building material, and the like can be used. Specifically, examples of the acid-modified polyolefin include Admer AT1000 and HE810 manufactured by Mitsui Chemicals, Inc., and Toyotac PMA-T manufactured by Toyobo, and examples of the chlorinated polyolefin include Supercron 814HS manufactured by Nippon Paper Industries, Examples include 390S and Hardlen 13-LP, 13-LLP manufactured by Toyobo. Examples of the acid-modified chlorinated polyolefin include Supercron 3228S and 2319S manufactured by Nippon Paper Industries and Hardlen HM-21P manufactured by Toyobo, and examples of the acrylic-modified chlorinated polyolefin include Supercron 224H and 240H manufactured by Nippon Paper Industries. Etc. are exemplified. Examples of the terpolymer of ethylene / acrylic acid / maleic anhydride include Bondyne series manufactured by Arkema. These modified polyolefins may be used alone or in combination of two or more.

When a layer in which the acrylic pressure-sensitive adhesive polymer (B) is previously blended with the modified polyolefin is laminated on the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition as a layer containing the modified polyolefin, a layer containing the modified polyolefin and The adhesive strength between the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition and the pressure-sensitive adhesive layer is increased, and the durability tends to be improved. In this case, the compounding amount of the acrylic adhesive polymer (B) to the modified polyolefin is 0.5 to 50% by weight based on the whole thin film layer containing the modified polyolefin as a main component. Preferably it is 0.5 to 30% by weight, more preferably 0.5 to 20% by weight, still more preferably 0.5 to 15% by weight, and still more preferably 0.5 to 10% by weight. When the blending amount of the acrylic pressure-sensitive adhesive polymer (B) to the modified polyolefin is within the above range, the adhesion between the layer containing the modified polyolefin and the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition is good. is there. Further, when the acrylic adhesive polymer (B) is blended with the modified polyolefin, it is also preferable in that a film having excellent smoothness and uniformity can be produced at the time of film formation.

総 The total amount of the modified polyolefin with respect to the entire layer containing the modified polyolefin is preferably 50% by weight or more. It is more preferably at least 60% by weight, further preferably at least 70% by weight, further preferably at least 80% by weight, still more preferably at least 90% by weight, and may be at least 100% by weight. When the content is 50% by weight or more, it is possible to secure the adhesiveness to the low-polarity base material.

The layer containing the modified polyolefin used in the present invention includes other components, for example, a plasticizer, an antioxidant, an ultraviolet absorber, an antioxidant, a flame retardant, and a fungicide, as long as the effects of the present invention are not impaired. And additives such as a silane coupling agent, a filler, and a coloring agent. The amount of the additive is preferably 0 to 10% by weight, more preferably 0 to 5% by weight, and still more preferably 0 to 2% by weight, based on the amount of the modified polyolefin used in the present invention. It is.

The method for producing the layer containing the modified polyolefin used in the present invention is not particularly limited, but a coating machine such as a gravure coater, a knife coater, and a slot die coater, gravure printing, offset printing, screen printing, inkjet printing, and the like. A method using a printing machine is preferable, and a method using a gravure coater is more preferable from the viewpoint of productivity.

<About the adhesive sheet>
The pressure-sensitive adhesive sheet provided by the present invention has a layer containing a modified polyolefin on at least one surface of a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition. That is, the pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition has a layer containing a modified polyolefin on one or both surfaces, the entire surface or a part of the surface.
For example, by transferring the layer containing the modified polyolefin formed on the separator to the surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, on the surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition A layer containing the modified polyolefin can be formed (transfer method).
Further, for example, a layer containing the modified polyolefin on the surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition by applying the pressure-sensitive adhesive composition over the layer containing the modified polyolefin formed on the separator It can be formed (overcoating method).
Among these methods, the multi-coating method is more preferable because a high peel strength to the adherend tends to be obtained and the number of release films used can be reduced.

By laminating the layer containing the modified polyolefin of the pressure-sensitive adhesive sheet prepared as described above on the adherend, a laminate can be prepared.
When the pressure-sensitive adhesive sheet provided by the present invention has a layer containing a modified polyolefin on one side of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, the decorative layer on the pressure-sensitive adhesive layer side formed from the pressure-sensitive adhesive composition Etc. can be laminated.
When the pressure-sensitive adhesive sheet provided by the present invention has a layer containing a modified polyolefin on both sides of a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition, the pressure-sensitive adhesive sheet can be laminated so that the pressure-sensitive adhesive sheet is sandwiched between adherends. .

The layer containing the modified polyolefin constituting the pressure-sensitive adhesive sheet provided in the present invention has no to slight tackiness at low temperature conditions such as room temperature, so that it is easy to handle and rework such as reattachment to an adherend. It has the characteristic of high performance.
Further, when the pressure-sensitive adhesive sheet provided by the present invention is used, a method for manufacturing home electric appliances, automobile interior members, and automobile exterior members such as bumpers, etc., in which the application of a primer to a low-polarity adherend such as polypropylene is omitted is realized. Therefore, the method has a feature that a process in a production line of a home appliance, an automobile, an automobile part, or the like can be simplified.

<Decorative film>
The pressure-sensitive adhesive sheet provided in the present invention can constitute a pressure-sensitive adhesive layer of a decorative film. The decorative film provided with the pressure-sensitive adhesive sheet provided by the present invention (hereinafter, also referred to as the present decorative film) exhibits high adhesiveness under high-temperature conditions and can exhibit excellent durability.

The decorative film can include a decorative layer and a base material layer in addition to the above-mentioned pressure-sensitive adhesive sheet. The decorative film having such a configuration can be suitably used when a decorative molded body is obtained by laminating the decorative film on a molded body (lamination method).

After the decorative film is decorated on the molded article, the base layer is located on the outermost layer of the decorative molded article described later, and functions as a protective layer of the decorative molded article. The material constituting the base material layer may be any material having flexibility, and is preferably plastic. More preferably, it is a thermoplastic. Although it does not specifically limit as a thermoplastic, Vinyl chloride (PVC) resin, polyester resin, acrylic resin, ABS resin, polycarbonate resin, polypropylene resin, polyethylene resin, etc. are mentioned. Among these, as a material used for the base material layer, a PVC resin, a polyester resin, and an ABS resin are preferable.

The thickness of the base material layer is preferably 25 μm to 500 μm, more preferably 50 μm to 400 μm, and still more preferably 100 to 300 μm. When the thickness of the base material layer is within the above range, when the decorative molded body is manufactured by an injection molding method (also referred to as an insert molding method), a vacuum molding method, a vacuum air pressure molding method, or the like, the formability and the shape of the molded body are reduced. Followability and handleability are improved.

The decorative layer is a layer provided for imparting a design property of the decorative film, and is formed by printing a pattern such as a text, a figure, a pattern, and a trademark by printing or the like. The pattern formed on the decorative layer can be formed by a known printing method such as gravure printing using printing ink, offset printing, silk screen printing, transfer printing from a transfer sheet, sublimation transfer printing, and inkjet printing.

(4) The thickness of the decorative layer is preferably 1 to 40 μm, more preferably 1 to 30 μm. When the thickness of the decorative layer is within the above range, a sufficient thickness for expressing a complicated design such as gradation can be secured.

(4) For the purpose of improving the design of the decorative film, an uneven pattern may be provided on the surface of the decorative film. The concavo-convex pattern can be transferred by passing through an emboss roller provided with the concavo-convex pattern.

最 A protective layer may be provided on the outermost surface of the decorative film for the purpose of improving the weather resistance, chemical resistance, stain resistance, abrasion resistance, electric insulation, etc. of the decorative film. The protective layer may be coated with a polymer material or the like having the above performance, or may be laminated with a film having the above performance.

The decorative film may further include a release layer on one side or both sides. The release layer is for preventing unintended adhesion, and is released when the decorative film is bonded to the molded product. The material constituting the release layer is not particularly limited. For example, a plastic film such as a polyester film such as polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate; or a material such as paper such as glassine paper, kraft paper, or clay coated paper is used. Can be. Their thickness can be about 10 to 400 μm.

In addition to the above, the present decorative film may have a configuration in which a hard coat layer (protective layer), a decorative layer, and an adhesive layer are provided on the release layer of the release film having the release layer. . The decorative film having such a configuration can be suitably used as a transfer film, and a decorative molded body can be obtained by transferring from the hard coat layer to the pressure-sensitive adhesive layer to the molded body (transfer method). In the case of the above-described laminating method, it is necessary to remove the surplus film by trimming after decorative molding. However, the transfer method does not require a trimming process, which is advantageous in terms of production efficiency.

The hard coat layer is preferably made of a material that can be cured and / or cross-linked by irradiating active energy rays or the like after being transferred to the molded article. Examples of the material constituting the hard coat layer include a polymer or oligomer having a (meth) acryloyl group, an active energy ray-curable composition which is irradiated with an appropriate amount of active energy rays to be in a semi-cured state, or an active energy ray. Examples of the composition include an isocyanate compound, a polyol resin, and the like mixed into the linearly curable resin composition and appropriately crosslinked.

厚み The thickness of the hard coat layer is not particularly limited, but can be about 1 to 50 μm, and preferably about 2 to 40 μm.

<Decoration molding>
The present invention can provide a decorative molded article provided with the decorative film (hereinafter, also referred to as the present decorative molded article). Since the present decorative molded article includes the decorative film provided with the pressure-sensitive adhesive sheet provided by the present invention, the decorative molded article does not float or peel even when exposed to high temperature and high humidity, and has excellent durability.

The molded body to which the decorative film is adhered is not particularly limited. For example, automobile interior parts, automobile exterior members such as bumpers, home electric appliances, goods to which the decorative film such as miscellaneous goods can be adhered. And so on. When the material of the molded body to which the decorative film is bonded is a low-polarity substance, the effects of the present invention are more exhibited, and in particular, a molded body made of polypropylene can be suitably used.

の通り As described above, a vacuum molding method, a vacuum pressure molding method, an injection molding method, or the like can be used for the production of the present decorative molded body. In the vacuum forming method, the decorative film is stretched while being softened by heating, and the space on the molded body side of the decorative film is decompressed, whereby the decorative film is adhered while being formed along the surface shape of the molded body. . In the vacuum pressure forming method, after the forming step of the vacuum forming method, the space on the opposite side is further pressurized, so that the decorative film is adhered while being formed along the surface shape of the formed body. In the injection molding method, the decorative film is set in a mold cavity of an injection molding machine, and the decorative film is bonded along the surface shape of the molded body by performing injection molding. By these methods, the present decorative molded body can be obtained.

Hereinafter, the present invention will be specifically described based on examples. Note that the present invention is not limited by these examples. In the following, "parts" and "%" mean parts by weight and% by weight, respectively, unless otherwise specified.
The method for analyzing the polymer obtained in the synthesis example is described below.

<Molecular weight measurement>
Using a gel permeation chromatograph (model name "HLC-8320", manufactured by Tosoh Corporation), a number average molecular weight (Mn) and a weight average molecular weight (Mw) in terms of polystyrene were obtained under the following conditions. The molecular weight distribution (Mw / Mn) was calculated from the obtained values.
Measurement conditions Column: TSKgel SuperMultipore HZ-M manufactured by Tosoh Corporation x 4 Column temperature: 40 ° C
Eluent: tetrahydrofuran Detector: RI
Flow rate: 600 μL / min

<Composition ratio of polymer>
The composition of the polymer was calculated from the amount of charged monomer and the amount of consumed monomer by GC measurement.
GC: manufactured by Agilent Technologies (7820A GC System)
Detector: FID
Column: 100% dimethyl siloxane (CP-Sil 5CB) Length 30m, inner diameter 0.32mm
Calculation method: Internal standard method

<Measurement of glass transition point (Tg)>
The Tg of the obtained polymer was determined from the intersection of the tangent at the inflection point with the baseline of the heat flux curve obtained using a differential scanning calorimeter. The heat flux curve was as follows: about 10 mg of the sample was cooled to −50 ° C., held for 5 minutes, then heated to 300 ° C. at 10 ° C./min, then cooled to −50 ° C., held for 5 minutes, and then cooled to 10 ° C./min. The temperature was raised to 350 ° C. in min.
Measuring equipment: DSC6220 manufactured by SII Nanotechnology Inc.
Measurement atmosphere: under nitrogen atmosphere

[Synthesis Example 1]
[Synthesis of Acrylic Adhesive Polymer (B-1)]
2-methoxyethyl acrylate (413 parts by weight, hereinafter referred to as "MEA") and 2-hydroxyethyl acrylate (27 parts by weight, hereinafter referred to as "HEA") as monomers are placed in a four-neck flask having an internal volume of 3 liters. And butyl acrylate (90 parts by weight, hereinafter referred to as "BA"), and ethyl acetate (980 parts by weight) as a solvent, and sufficiently degassed the mixture by bubbling nitrogen gas. To 75 ° C., and as a polymerization initiator, 2,2′-azobis (2,4-dimethylvaleronitrile) (trade name “V-65” manufactured by Wako Pure Chemical Industries, Ltd .; hereinafter, referred to as “V-65”) ( 0.25 parts by weight) to initiate polymerization. Five hours later, ethyl acetate was added so that the solid content became 30% by weight to obtain an ethyl acetate solution of the acrylic adhesive polymer B-1. The obtained acrylic pressure-sensitive adhesive polymer B-1 was composed of 78% by weight of MEA, 17% by weight of BA, and 5% by weight of HEA, and had Mw of 572,000, Mn of 160000, and Mw / Mn of 3.58. Tg was -35 ° C. Table 1 shows the composition and analysis result of the polymer B-1.

[Synthesis Example 2] to [Synthesis Example 5]
[Synthesis of Acrylic Adhesive Polymers (B-2) to (B-5)]
Except that the types (MEA, BA, HEA, methyl acrylate (hereinafter referred to as “MA”)) and composition of the monomers used and the amount of the polymerization initiator V-65 were changed as shown in Table 1. By the same operation as in [Synthesis Example 1], acrylic tacky polymers (B-2) to (B-5) were obtained. Composition and analysis of acrylic adhesive polymer (B-2) to (B-5)

[Synthesis Example 6]
[Synthesis of acrylic adhesive polymer (B-6)]
In a four-necked flask having an inner volume of 1 L, dibenzyltrithiocarbonate (3.18 parts by weight) as a RAFT agent, styrene (75 parts by weight, hereinafter referred to as “St”) as a monomer, and N-phenylmaleimide (125 Parts, hereinafter referred to as “PhMI”), acetonitrile (466 parts by weight) as a solvent, degassing sufficiently by bubbling with nitrogen, raising the internal temperature of the mixture to 70 ° C., and using 2,2′-azobis as a polymerization initiator. (2-Methylbutyronitrile) (0.51 part by weight, hereinafter referred to as ABN-E) was charged to initiate polymerization. After 3 hours, the reaction was stopped by cooling to room temperature. The polymer solution was purified by reprecipitation from methanol and vacuum drying to obtain a polymer block a. The obtained polymer block a had Mn of 10,900. Tg was 206 ° C.
Polymer block a (21.1 parts by weight) obtained in a four-necked flask having an internal volume of 1 L, MEA (234 parts by weight), BA (51 parts by weight), and HEA (15 parts by weight) as monomers Acetonitrile (107 parts by weight) was charged as a solvent, degassed sufficiently with nitrogen bubbling, the internal temperature of the mixture was raised to 70 ° C., and ABN-E (0.08 parts by weight) was charged as a polymerization initiator to carry out polymerization. Started. After 6 hours, the mixture was cooled to room temperature, and acetonitrile was added to adjust the solid content concentration to 30% to obtain an adhesive solution. The resulting aba block copolymer B-6 was composed of 3% by weight of PhMI, 2% by weight of St, 74% by weight of MEA, 16% by weight of BA, and 5% by weight of HEA. Mw 358,000, Mn 16,0000, Mw / Mn was 2.24. Tg was -35 ° C. Table 2 shows the composition and analysis result of the polymer B-6.

[Synthesis Example 7]
[Synthesis of low molecular weight vinyl polymer (A-1)]
In a four-necked flask having an inner volume of 1 liter, 200 parts by weight of butyl acetate as a solvent and dimethyl 2,2′-azobis (2-methylpropionate) as a polymerization initiator (trade name “V- 601 "), a mixed solution consisting of 0.9 parts by weight was charged, and the mixed solution was sufficiently degassed by bubbling nitrogen gas, and the internal temperature of the mixed solution was raised to 90 ° C. Separately, 165 parts by weight of methyl methacrylate (hereinafter, referred to as "MMA") as a monomer, 44 parts by weight of isobornyl methacrylate (hereinafter, referred to as "IBXMA"), 17 parts by weight of V-601 as a polymerization initiator, Was polymerized by dropping a mixed solution consisting of 90 parts by weight of butyl acetate from a dropping funnel into the flask over 5 hours. After completion of the dropping, the vinyl polymer in the polymerization solution was isolated by dropping the polymerization solution into a mixed solution consisting of 4800 parts by weight of methanol and 1200 parts by weight of distilled water to obtain a low molecular weight vinyl polymer A-1. . The monomer composition of the obtained low molecular weight vinyl polymer A-1 was 80% by weight of MMA and 20% by weight of IBXMA as calculated from the charged amount and the monomer consumption by GC measurement. The molecular weight was Mw 6,700, Mn 4,370, and the molecular weight distribution Mw / Mn was 1.53. Tg was 108 ° C. Table 3 shows the composition and analysis results of the low molecular weight vinyl polymer A-1.

[Synthesis Example 8] and [Synthesis Example 9]
[Synthesis of low molecular weight vinyl polymers (A-2) and (A-3)]
The same operation as in [Synthesis Example 7] was performed, except that the composition of the monomers used and the amount of the polymerization initiator V-601 used were changed as shown in Table 2, to obtain a low-molecular-weight vinyl polymer (A- 2) and (A-3) were synthesized. Table 3 shows the analysis results of the low molecular weight vinyl polymers (A-2) and (A-3).

<Preparation of adhesive composition>
Acrylic adhesive polymer (B-1 to B-6) obtained in the above synthesis example, tackifier (low molecular weight vinyl polymer (A-1 to A-3), or rosin ester KE manufactured by Arakawa Chemical Co., Ltd.) -311 (D-1)) and a cross-linking agent (Takenate D-110N (D-110N) manufactured by Mitsui Chemicals, Inc.) in the number of parts shown in Tables 3 to 5, respectively, and acetic acid so that the solid content concentration becomes 30% by weight. Ethyl was added to obtain an ethyl acetate solution of the pressure-sensitive adhesive composition.

[Example 1]
An adhesive sheet was prepared in the following procedure.
(1) Coating of Thin Film Modified polyolefin C-1 (Toyotach PMA-T manufactured by Toyobo Co., Ltd.) was dissolved in toluene to prepare a solution having a solid content of 5% by weight. This solution was applied to a 38 μm-thick polyethylene terephthalate (hereinafter, “PET”) separator using a doctor blade so that the thickness after drying was 1 μm. The coating was dried at 80 ° C. for 1 minute.
(2) Transfer As described above, the pressure-sensitive adhesive composition was dissolved in ethyl acetate to prepare a solution having a solid content of 30% by weight. This solution was applied on a 38 μm thick PET separator using a doctor blade so that the thickness after drying was 50 μm. The coating was dried at 80 ° C. for 4 minutes. After curing at 40 ° C. for 5 days, a thin film surface of the PET separator with a thin film prepared in (1) was bonded to one surface of the pressure-sensitive adhesive sheet to obtain a pressure-sensitive adhesive sheet sample with a double-sided separator.
The peel strength of the obtained pressure-sensitive adhesive sheet sample was evaluated by the following method. Table 4 shows the obtained results.

<Gel fraction based on pressure-sensitive adhesive composition>
0.2 g of the pressure-sensitive adhesive composition was sampled from the pressure-sensitive adhesive sheet sample, and the initial weight of the pressure-sensitive adhesive composition was weighed. The adhesive composition was immersed in 50 g of ethyl acetate and allowed to stand at room temperature for 16 hours. Thereafter, the mixture was filtered through a 200 mesh wire net, and the residue remaining on the mesh was dried at 80 ° C. for 3 hours and weighed. From the initial weight and the residual weight, the gel fraction with respect to the acrylic adhesive polymer (B) was calculated by the following equation.
Gel fraction (%) = (residual weight) / [(initial weight) × (solid content of acrylic adhesive polymer (B)) / (solid content of entire adhesive composition)] × 100

<Tg of the surface layer portion of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition>
From the peak area ratio of O1s and C1s measured by an X-ray photoelectron spectrometer (XPS) of the pressure-sensitive adhesive sheet sample, the vinyl polymer (A) and the acrylic pressure-sensitive polymer in the surface layer of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition The mass fraction (wA and wB) of the vinyl polymer (A) and the acrylic adhesive polymer (B) with respect to the total amount of (B) was calculated, and the Tg of the surface layer was calculated based on the formula of FOX.
The XPS measurement was performed under the following conditions.
Apparatus: PHI5000 VersaProbe manufactured by ULVAC-PHI
X-ray: Al-Kα (1486.6 eV)
X-ray incidence angle on sample: 0 ° (angle with respect to the normal line of sample measurement surface)
Photoelectron detection angle: 45 ° (angle with respect to the normal to the sample measurement surface)

The specific calculation method of the mass fraction will be described below.
The ratio of the number of oxygen atoms to the number of carbon atoms calculated from the peak area ratio of O1s and C1s by XPS measurement is composed of a vinyl polymer (A) and an acrylic adhesive polymer (B) as in the following formula (2). It is represented by the ratio of the number of oxygen atoms to the number of carbon atoms per unit weight of the surface layer of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition.

here,
(O / C) A + B: ratio WA of the number of oxygen atoms to the number of carbon atoms calculated from the peak area ratio of O1s and C1s obtained from the XPS measurement of the pressure-sensitive adhesive layer obtained by drying the pressure-sensitive adhesive composition. : Mass fraction of vinyl polymer (A) based on total amount of vinyl polymer (A) and acrylic adhesive polymer (B) Mw-A: weighted average molecular weight of all constituent monomer units of vinyl polymer (A) Mw-B: Weighted average molecular weight of all constituent monomer units of acrylic pressure-sensitive adhesive composition (B) NO-A: Average monomer structural formula of all constituent monomers of vinyl polymer (A) Number of oxygen atoms contained in NO-B: average number of all constituent monomers constituting the acrylic adhesive polymer (B) Number of oxygen atoms contained in the monomer structural formula NC-A: vinyl polymer (A) Average number of carbon atoms contained in the average monomer structural formula of all the constituent monomers of the formula: NC-B: acrylic tacky poly Average number of carbon atoms contained in the monomer structural formula of all the constituent monomers constituting the mer (B)

Further, the number of carbon atoms and oxygen atoms calculated from the peak area ratio of O1s and C1s obtained by XPS measurement of a film obtained by drying each of the vinyl polymer (A) and the acrylic adhesive polymer (B) alone. The ratio of the numbers is represented by the following equations (3) and (4), respectively.

here,
(O / C) A: ratio of the number of oxygen atoms to the number of carbon atoms calculated from the peak area ratio of O1s and C1s obtained from the XPS measurement of the film obtained by drying the vinyl polymer (A)

here,
(O / C) B: the ratio of the number of oxygen atoms to the number of carbon atoms calculated from the peak area ratio of O1s and C1s obtained from the XPS measurement of the film obtained by drying the acrylic adhesive polymer (B)

The following formula (5) is derived from the above formulas (2) to (4), from which the mass fraction of the vinyl polymer (A) to the total amount of the vinyl polymer (A) and the acrylic adhesive polymer (B) is obtained. (WA) is calculated.

Further, the mass fraction (WB) of the acrylic adhesive polymer (B) is calculated from the value of WA obtained above and the following equation (6).

here,
WB: mass fraction of acrylic adhesive polymer (B) based on total amount of vinyl polymer (A) and acrylic adhesive polymer (B)

With respect to [Embodiment 10], each element in the above formula (4) is shown below.
(O / C) A + B: 0.316 (actual value)
(O / C) A: 0.290 (actual value)
(O / C) B: 0.465 (actual value)
NC-A: 5 × 89.9 (mol%) + 14 × 10.1 (mol%) = 5 from the number of carbon atoms in one MMA molecule (5), the number of carbon atoms in one IBXMA molecule (14), and the composition ratio. .91NC-B: 6 × 84.4 (mol%) from the number of carbon atoms in one MEA molecule (6), the number of carbon atoms in one BA molecule (7), the number of carbon atoms in one HEA molecule (5), and the composition ratio. ) + 7 × 10.1 (mol%) + 5 × 5.6 (mol%) = 6.05
Mw-A: From the molecular weight of MMA (100), the molecular weight of IBXMA (222), and the composition ratio, 100 × 89.9 (mol%) + 222 × 10.1 (mol%) = 11.3 Mw-B: molecular weight of MEA (130), the molecular weight of BA (128), the molecular weight of HEA (116), and the composition ratio, 130 × 84.4 (mol%) + 128 × 10.1 (mol%) + 116 × 5.6 (mol%) = 129.1
By substituting these values into equation (4), WA = 0.636 was obtained, and from equation (5), WB = 0.164 was obtained.

Next, the Tg of the surface layer portion was calculated from the surface composition obtained in the measurement according to the FOX formula represented by the following formula (6), and a value of 73.8 ° C. was obtained.
1 / [Tg of surface layer portion] (K) = WA / TgA + WB / TgB (6)
here,
TgA: Tg of vinyl polymer (A) (108 ° C.)
TgB: Tg of acrylic adhesive polymer (B) (-35 ° C)

<Peel strength for polypropylene>
The surface of the pressure-sensitive adhesive composition side of the pressure-sensitive adhesive sheet sample obtained above is bonded to an easily-adhesive PET film (trade name: Lumilar 125U34, 125 μm thick, manufactured by Toray Industries, Inc.), and the surface on the thin film side is adhered to a polypropylene plate ( Sumitomo Chemical Co., Ltd., trade name: Noblen, 2 mm thickness, hereinafter referred to as “PP”, heat treatment at 120 ° C., 0.8 MPa, for 20 seconds, and a tensile tester with a thermostat, Strograph R type (Toyo Seiki Co., Ltd.) Manufactured at a temperature of 23 ° C. or 85 ° C. and a peeling rate of 300 mm / min. The 180 ° peel strength of the pressure-sensitive adhesive sheet was measured according to JIS Z-0237 “Testing method for pressure-sensitive adhesive tape / pressure-sensitive adhesive sheet” under the conditions described in the above, and the peel strength to PP was determined.

Details of [Table 4] to [Table 6] are as follows.
Crosslinking agent D-110N: Takenate D-110N manufactured by Mitsui Chemicals, trimethylolpropane adduct of meta-xylylene diisocyanate, nonvolatile component 75.0%, NCO content 11.5%
-Modified polyolefin C-1: Toyobo tack PMA-T manufactured by Toyobo, maleic anhydride-modified propylene / butene copolymer, degree of modification 1.5% by weight, weight average molecular weight 55,000, melting point 95 ° C
Modified polyolefin C-2: Harden HM-21P manufactured by Toyobo, maleic anhydride-modified chlorinated ethylene / propylene copolymer, maleic anhydride modification degree 1.6% by weight, chlorination modification degree 21% by weight, weight average molecular weight 45,000, melting point 87 ° C
-Modified polyolefin C-3: Nippon Paper Industries Supercron 814HS, chlorinated propylene, degree of chlorination modification 41% by weight, weight average molecular weight 10,000 to 30,000, melting point 65 ° C
Tackifier D-1: Rosin ester KE-311 manufactured by Arakawa Chemical Co., Ltd., softening point 90-100 ° C

[Example 2] to [Example 18] and [Comparative Example 1] to [Comparative Example 6]
As shown in Tables 4 to 6, the same operation as in [Example 1] was performed except that the compositions of the modified polyolefin layer and the pressure-sensitive adhesive layer were changed, and the peel strength to PP was measured. The results are shown in Tables 4 to 6.

[Example 19]
An adhesive sheet was prepared in the following procedure.
(1) Coating of Thin Film Modified polyolefin C-1 (Toyotach PMA-T manufactured by Toyobo Co., Ltd.) was dissolved in toluene to prepare a solution having a solid content of 5% by weight. This solution was applied to a 38 μm-thick polyethylene terephthalate (hereinafter “PET”) separator using a doctor blade so that the thickness after drying was several μm. The coating was dried at 80 ° C. for 1 minute.
(2) Overcoating An ethyl acetate solution (solid content of 30% by weight) of the pressure-sensitive adhesive composition shown in Table 5 was directly dried on a PET-made separator with a thin film of a thermoplastic resin prepared in (1). The coating was performed using a doctor blade so that the thickness became 50 μm. The coating was dried at 80 ° C. for 4 minutes. A 38-μm-thick PET separator having a different peeling force from the separator was stuck together, and left to stand at 40 ° C. for 5 days for aging to obtain a pressure-sensitive adhesive sheet sample with a double-sided separator.

について About the obtained adhesive sheet sample, the peel strength with respect to PP was evaluated by the above-mentioned method. Table 7 shows the obtained results.

[Example 20] to [Example 36]
As shown in Tables 7 and 8, the same operation as in [Example 19] was performed except that the composition of the layer containing the modified polyolefin and the composition of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition were changed, and peeling to PP was performed. The strength was measured. The results are shown in Tables 7 and 8.

Evaluation results
(1) Transfer method The peel strength of polypropylene from [Example 1] to [Example 18] using the pressure-sensitive adhesive sheet prepared by the transfer method was 10 N / 25 mm or more at 23 ° C. It was found to show high peel strength. Further, under the condition of 85 ° C., all showed a peel strength of 3.5 N / 25 mm or more, and it was found that a high peel strength was maintained although a decrease in the numerical value was observed with an increase in the measurement temperature. On the other hand, even if the composition of the pressure-sensitive adhesive composition was the same as that of the example, the comparative examples 1 to 3, which did not have the layer containing the modified polyolefin, the comparative example 2 and the comparative example 6 had a temperature of 23 ° C. It was found that the peel strength below was lower than in the corresponding examples. [Comparative Example 3] is a case where a rosin ester was used as the tackifier. The peel strength under 23 ° C. condition was extremely high, but the peel strength under 85 ° C. condition was significantly reduced. Was. [Comparative Example 5] is a sheet obtained by laminating a rosin ester as a thin film layer on a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition. Did not. [Comparative Example 4] is a case where the chlorinated polyolefin was uniformly mixed in the pressure-sensitive adhesive composition without forming a thin film layer. Under the condition of ° C, a remarkable decrease in peel strength was observed.
From the above results, the problem of providing a pressure-sensitive adhesive sheet having excellent adhesiveness not only at room temperature but also at high temperature for a low-polarity substrate was formed from the pressure-sensitive adhesive composition provided by the present invention. It was shown that a pressure-sensitive adhesive sheet having a layer containing a modified polyolefin on at least one surface of the pressure-sensitive adhesive layer thus obtained can be suitably used.

In Examples 10 to 18 using a low molecular weight vinyl polymer as a tackifier, the peel strength at 23 ° C. was very high. Among them, Examples 10 to 15 using low-molecular-weight vinyl polymers whose molecular weight, molecular weight distribution and Tg satisfy the preferable ranges described above have peel strengths of 10 N / 25 mm at 85 ° C. Was exceeded. In particular, an acrylic adhesive polymer was previously mixed in the layer containing the modified polyolefin [Example 11], and an acrylic adhesive polymer containing methyl acrylate having 1 carbon atom as a constituent monomer was used [Example 13]. ] And [Example 14], and [Example 15] in which a high molecular weight acrylic adhesive polymer containing methyl acrylate having 1 carbon atom was used as a constituent monomer, was used at 85 ° C. An extremely high peel strength of 13.5 to 17.3 N / 25 mm was obtained.
Further, in the [Example 6], [Example 7], [Example 11] and [Example 12] in which an acrylic tacky polymer was previously mixed into the layer containing the modified polyolefin, smoothness and homogeneity were obtained. It was found that an excellent film was easily formed.

(2) Overcoating method The peel strength to polypropylene of [Example 19] to [Example 36] using the adhesive sheet prepared by the overcoating method is almost the same as that using the adhesive sheet prepared by the transfer method. It was the tendency. It has been found that the pressure-sensitive adhesive sheet provided by the present invention has high adhesive strength to a low-polar substrate under room temperature and high temperature conditions, regardless of which preparation method is used. On the other hand, in many examples, higher peel strength was obtained under room temperature and high temperature conditions when the pressure-sensitive adhesive sheet prepared by the overcoating method was used than when the pressure-sensitive adhesive sheet prepared by the corresponding transfer method was used. Was.

Since the pressure-sensitive adhesive sheet and the decorative film provided by the present invention exhibit high adhesive strength to a low-polarity material such as polypropylene which is hardly adherent at room temperature and high temperature, they are used for home electric appliances and automobile interior parts. And for the production of automobile exterior members such as bumpers.

Claims

(4) A pressure-sensitive adhesive sheet having a layer containing a modified polyolefin on at least one surface of a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition.
The pressure-sensitive adhesive sheet according to claim 1, wherein the modified polyolefin is an acid-modified polyolefin.
The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive composition comprises an acrylic pressure-sensitive adhesive composition.
The acrylic pressure-sensitive adhesive composition contains a vinyl polymer (A) and an acrylic pressure-sensitive adhesive polymer (B), and the vinyl polymer (A) has a glass transition point (Tg) of 30 ° C or more and 200 ° C or less. Having a number average molecular weight of 500 to 10,000, and containing 0.5 to 60 parts by weight based on 100 parts by weight of the acrylic pressure-sensitive adhesive polymer (B). When the pressure-sensitive adhesive composition is applied to a separator and dried to obtain a pressure-sensitive adhesive composition layer, the first Tg, which is the Tg of the entire pressure-sensitive adhesive composition layer, is −80 ° C. or more and 10 ° C. or less. The second Tg, which is a Tg calculated from a surface layer portion obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive composition layer, is higher than the first Tg by 30 ° C. or more. 4. The pressure-sensitive adhesive sheet according to 3.
5. The pressure-sensitive adhesive composition according to claim 1, wherein the pressure-sensitive adhesive composition contains an acrylic pressure-sensitive adhesive polymer (B), and the thin film layer containing a modified polyolefin as a main component contains the acrylic pressure-sensitive adhesive polymer (B). The pressure-sensitive adhesive sheet according to claim 1.
The method for producing a pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein
A method for producing a pressure-sensitive adhesive sheet, comprising forming a layer containing the modified polyolefin on a release film.
The method for producing a pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein
After forming a layer containing the modified polyolefin, by applying a pressure-sensitive adhesive composition over the layer, the layer containing the modified polyolefin on the surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition A method for producing a pressure-sensitive adhesive sheet, characterized in that it is formed.
加 A decorative film comprising the pressure-sensitive adhesive sheet according to any one of claims 1 to 5.
加 A decorative molded article, characterized in that the decorative film according to claim 8 is adhered to the molded article.