WO2020256118A1

WO2020256118A1 - Adhesive sheet for vacuum pressure molding and use of same

Info

Publication number: WO2020256118A1
Application number: PCT/JP2020/024173
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: 2019-06-21
Filing date: 2020-06-19
Publication date: 2020-12-24
Also published as: JP7347508B2; JPWO2020256118A1

Abstract

An adhesive sheet for vacuum pressure molding, which comprises an adhesive layer that is formed of an adhesive composition and a thin film layer, wherein: the thin film layer is arranged on at least one surface of the adhesive layer and has a thickness thinner than that of the adhesive layer, while having a melting point, a softening point or a glass transition temperature (Tg) of 70°C or higher; or the thin film layer is a surface layer part of the adhesive layer and has a Tg of 70°C or higher, said Tg being calculated from the composition of the surface layer part obtained by X-ray photoelectron spectroscopy of the adhesive layer.

Description

Adhesive sheet for vacuum compressed air molding and its use

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2019-115239, which was filed on June 21, 2019, and the contents of the description are incorporated herein by reference.

This disclosure relates to an adhesive sheet for vacuum compressed air molding and its use.

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

Furthermore, the adhesive is also used for decorative films for the purpose of protecting members such as home appliances or automobile interior / exterior supplies and imparting design. As a molding method using a decorative film, in addition to in-mold molding by injection molding, a method of bonding or transferring to a molded product by vacuum forming, vacuum pressure air forming, or the like is used. Here, when molding by laminating, the decorative film has a structure in which a decorative layer, an adhesive layer, and the like are laminated on a base material layer made of a thermoplastic resin such as a vinyl chloride resin or a polyolefin resin. Is used. Further, in the case of molding by transfer, the laminate including the protective layer, the decorative layer and the pressure-sensitive adhesive layer is transferred to the surface of the molded body. Decorative films for vacuum forming having such an adhesive layer are disclosed (Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2012-213891 Japanese Unexamined Patent Publication No. 2012-213894

In the use of decorative films, it is required to follow complicated shapes such as curved surfaces and uneven parts. Therefore, among the above-mentioned molding methods, "vacuum compressed air molding" is attracting attention. This is a method in which a decorative film made of a thermoplastic resin is heated and softened, a vacuum is created between the mold or the base material and the decorative film, and the decorative film is brought into close contact with the mold or the base material by compressed air pressure. is there.

However, when the decorative film for vacuum forming described in Patent Documents 1 and 2 is used for "vacuum pressure air forming", although the adhesiveness at room temperature is good, the decorative film after being attached to the base material has a line shape. Poor appearance (so-called "shock line", "shock mark") may occur due to the occurrence of unevenness.

The present disclosure has been made in view of the above circumstances, and the purpose of the present disclosure is to provide an adhesive sheet for vacuum compressed air molding, which can suppress the occurrence of shock lines on a decorative film after being attached to a base material. It is to provide the decorative film used and the decorative molded article provided with the decorative film.

As a result of diligent studies to solve the above problems, the present inventors have found that the shock line can be suppressed by using a specific pressure-sensitive adhesive sheet for vacuum pressure molding. The disclosure is as follows.

[1] It has a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition and a thin-film layer, and the thin-film layer is arranged on at least one side of the pressure-sensitive adhesive layer, is thinner than the pressure-sensitive adhesive layer, and is the thin film. The melting point, softening point or glass transition temperature (Tg) of the layer is 70 ° C. or higher, or the thin film layer is a surface layer portion of the pressure-sensitive adhesive layer and is obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive layer. An adhesive sheet for vacuum pressure air forming in which Tg calculated from the composition of the surface layer portion is 70 ° C. or higher.
[2] The pressure-sensitive adhesive sheet for vacuum compressed air molding according to [1], wherein the pressure-sensitive adhesive composition is an acrylic pressure-sensitive pressure-sensitive adhesive composition.
[3] 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 Tg of 30 ° C. or higher and 200 ° C. or lower. The number average molecular weight is 500 to 10,000, and it is contained in an amount of 0.5 parts by mass or more and 60 parts by mass or less with respect to 100 parts by mass of the acrylic adhesive polymer (B), and the pressure-sensitive adhesive layer is the adhesive. The first Tg, which is the Tg of the entire agent layer, is −80 ° C. or higher and 20 ° C. or lower, and the second Tg is calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopic analysis of the pressure-sensitive adhesive layer. The pressure-sensitive adhesive sheet for vacuum pressure air forming according to [2], wherein the Tg is higher than that of the first Tg by 30 ° C. or more.
[4] The pressure-sensitive adhesive sheet for vacuum compressed air molding according to [3], which contains the vinyl polymer (A) at a higher concentration in at least one surface layer portion of the pressure-sensitive adhesive layer.
[5] Any of [1] to [4], wherein the thin film layer contains at least one selected from the group consisting of a polyolefin resin, a rosin ester resin, a polyester resin, and a (meth) acrylic resin. The pressure-sensitive adhesive sheet for vacuum pressure forming according to 1.
[6] The method for producing an adhesive sheet for vacuum compressed air molding according to any one of [1] to [5].
A method for producing an adhesive sheet for vacuum compressed air molding, in which the thin film layer is formed on a release film.
[7] A method for producing an adhesive sheet for vacuum pressure air forming, which includes a step of forming a thin film layer and a step of applying an adhesive composition on the thin film layer to form an adhesive layer. A method for producing a pressure-sensitive adhesive sheet for vacuum pressure air forming, wherein the thin film layer is thinner than the pressure-sensitive adhesive layer, and the melting point, softening point, or glass transition temperature (Tg) of the thin film layer is 70 ° C. or higher.
[8] A decorative film having the pressure-sensitive adhesive sheet for vacuum pressure molding according to any one of [1] to [5].
[9] A decorative molded body formed by attaching the decorative film according to [8] to the molded body.

According to the pressure-sensitive adhesive sheet for vacuum pressure molding of the present disclosure, it is possible to suppress the occurrence of shock lines on the decorative film after being attached to the base material. In addition, a decorative molded body provided with such a decorative film can be obtained.

Hereinafter, various embodiments of the techniques disclosed in the present specification will be described in detail. In addition, in this specification, "(meth) acrylic" means acrylic and / or methacrylic, and "(meth) acrylate" means acrylate and / or methacrylate. Further, the “(meth) acryloyl group” means an acryloyl group and / or a methacryloyl group.

The pressure-sensitive adhesive sheet for vacuum pressure molding of the present disclosure has a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition and a thin film layer. The thin film layer of the pressure-sensitive adhesive sheet for vacuum compressed air molding of the present disclosure is the following [1] or [2].
[1] The thin film layer is arranged on at least one surface of the pressure-sensitive adhesive layer, the thin film layer is thinner than the pressure-sensitive adhesive layer, and the melting point, softening point, or glass transition temperature (Tg) of the thin film layer is 70 ° C. That is all.
[2] The thin film layer is a surface layer portion of the pressure-sensitive adhesive layer, and Tg calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive layer is 70 ° C. or higher.

The pressure-sensitive adhesive sheet for vacuum pressure air forming of the present disclosure is particularly effective when preformed at a temperature at which the adhesiveness of the thin film layer does not develop and then vacuum pressure air forming at a temperature at which the adhesiveness of the thin film layer develops. The pressure-sensitive adhesive composition according to the present disclosure (hereinafter, also referred to as "the present pressure-sensitive adhesive composition"), the thin film layer according to the present disclosure (hereinafter, also referred to as the "the present thin film layer"), and the pressure-sensitive adhesive for vacuum pressure forming of the present disclosure. Details of a method for producing a sheet (hereinafter referred to as “the present pressure-sensitive adhesive sheet”), a decorative film and a decorative molded body, and a preferred embodiment of the present pressure-sensitive adhesive composition will be sequentially described.

1. 1. The Adhesive Composition The type of the adhesive composition is not particularly limited as long as it satisfies the required performance according to the application such as adhesiveness, heat resistance, weather resistance, and chemical resistance, and is an acrylic pressure-sensitive adhesive. Examples thereof include compositions, polyester-based pressure-sensitive adhesive compositions, urethane-based pressure-sensitive adhesive compositions, silicone-based pressure-sensitive adhesive compositions, and rubber-based pressure-sensitive adhesive compositions. Among these, an acrylic pressure-sensitive adhesive composition is preferable because it has an excellent balance between durability and cost.

The acrylic pressure-sensitive adhesive composition preferably contains an acrylic pressure-sensitive adhesive polymer (B). Further, the acrylic pressure-sensitive adhesive composition preferably contains a vinyl polymer (A) having a specific glass transition temperature and a number average molecular weight, and an acrylic pressure-sensitive adhesive polymer (B). When the acrylic pressure-sensitive adhesive composition contains the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B), the vinyl polymer (A) is segregated on the surface layer of the pressure-sensitive adhesive layer to cause the pressure-sensitive adhesive layer. It is preferable to control the glass transition temperature of the surface layer portion.

Due to the segregation of the vinyl polymer (A) in the pressure-sensitive adhesive layer, the Tg calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive layer is higher than the Tg of the entire pressure-sensitive adhesive layer by 30 ° C. or more. It is preferable to do so. As a result, the adhesive properties of the pressure-sensitive adhesive layer can be controlled to obtain good adhesive strength. That is, since it has a relatively high Tg in the vicinity of the adhesive interface formed of the surface layer of the pressure-sensitive adhesive, it is possible to exhibit good adhesiveness which has never been seen before. Further, even at a high temperature, the adhesive layer can be suppressed from being displaced or peeled off, and good durability can be exhibited. The segregation behavior of the vinyl polymer (A) on the surface layer of the pressure-sensitive adhesive layer is such that the specific vinyl polymer (A) and the acrylic adhesive polymer (B) are not completely compatible with each other, but are completely phase-separated. Based on not. Preferably, the vinyl polymer (A) has a lower polarity than the acrylic adhesive polymer (B).

As the vinyl polymer (A), it is preferable to use a vinyl polymer that is completely incompatible with the acrylic adhesive polymer (B). At that time, the degree of segregation can be adjusted by appropriately adjusting the amount of the vinyl polymer (A) used in the pressure-sensitive adhesive composition. If the amount of the vinyl polymer (A) used is too small, segregation on the surface layer of the pressure-sensitive adhesive layer becomes insufficient, and a sufficient effect may not be obtained. On the other hand, if the amount of the vinyl polymer (A) used is too large, the adhesive layer tends to have poor transparency and adhesive performance as a result of phase separation from the acrylic adhesive polymer (B). In addition, the glass transition temperature of the vinyl polymer (A), the amount of the cross-linking agent, and the like are appropriately adjusted, whereby the glass transition temperature of the surface layer portion of the pressure-sensitive adhesive layer can be adjusted. The vinyl polymer (A), the acrylic adhesive polymer (B) and other components will be described in detail in "5. Preferred Embodiments of the Adhesive Composition" described later.

The thickness of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition used in the present invention is appropriately selected according to 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.

2. 2. This thin film layer This thin film layer has an adhesive surface with an adherend when the present adhesive sheet is adhered to the adherend by vacuum compressed air molding. As described above, this thin film layer is arranged on at least one surface of the pressure-sensitive adhesive layer, is a layer thinner than the pressure-sensitive adhesive layer, and has a melting point, softening point, or Tg of 70 ° C. or higher (hereinafter referred to as “thin film layer”). (Also referred to as "thin film layer 1"), or a Tg calculated from the composition of the surface layer portion of the pressure-sensitive adhesive layer obtained by X-ray photoelectron spectroscopic analysis of the pressure-sensitive adhesive layer is 70 ° C. The above thin film layer (hereinafter, also referred to as “thin film layer 2”). The thickness of the thin film layer is appropriately selected according to the purpose of use, and is not particularly limited. The thickness of the thin film layer is, for example, 0.001 to 50 μm, for example 0.005 to 20 μm, and for example 0.01 to 15 μm, as an average value of the entire thin film layer. It is 0.01 to 10 μm.

Here, the pressure-sensitive adhesive sheet for vacuum pressure molding having the present thin film layer is easy to handle because the present thin film layer has no to fine tackiness under low temperature conditions such as room temperature. Further, the present adhesive sheet and the decorative film having the present adhesive sheet are preformed at a temperature at which the adhesiveness of the thin film layer does not appear (hereinafter, also referred to as "first temperature"), and then the thin film layer is adhered. It has a feature that it is particularly effective when it is heated and pressurized at a temperature at which the property is exhibited (hereinafter, also referred to as “second temperature”) and adheres to the adherend. When the above-mentioned preliminary shaping is performed, the process from preliminary shaping to bonding may be performed in the same vacuum compressed air forming machine, or after performing the preliminary shaping in a device different from the vacuum compressed air forming machine, vacuum compressed air forming is performed. It may be put into a machine and bonded by heating and pressurizing. Examples of the vacuum compressed air forming machine include a hot plate type pressure reducing coating molding machine (TFH series) manufactured by Asano Laboratories, a TOM molding machine manufactured by Fuse Vacuum (NGF series), and a NATS air transfer machine manufactured by Navitas. Among these, a NATS air transfer machine capable of uniformly heating and compressing the molded product with high-temperature steam is preferable because it suppresses shock lines and exhibits high adhesiveness. It is also possible to use a vacuum forming machine or a compressed air forming machine having a principle similar to that of the vacuum forming machine.

The first temperature is, for example, less than 100 ° C., preferably 95 ° C. or lower. The lower limit of the first temperature is, for example, 20 ° C. or higher, preferably 40 ° C. or higher, and more preferably 50 ° C. or higher. The second temperature may be a temperature on the higher temperature side than the first temperature, but is, for example, 100 ° C. or higher, preferably 110 ° C. or higher. The upper limit of the second temperature is, for example, 230 ° C. or lower, preferably 200 ° C. or lower.

2-1. Thin film layer 1
The thin film layer 1 has a melting point, a softening point, or a Tg of 70 ° C. or higher. Examples of the thin film layer 1 include a thin film layer formed of a thermoplastic resin having a melting point, softening point, or Tg of 70 ° C. or higher. Examples of the thermoplastic resin include polyolefin resins, rosin ester resins, polyester resins, (meth) acrylic resins, terpene resins, styrene and other petroleum resins, ethylene / vinyl acetate resins, vinyl chloride / vinyl acetate. Examples thereof include based resins, urethane resins and the like, and adhesive compositions containing these resins. Among these, it is preferable to include at least one selected from the group consisting of polyolefin resins, rosin ester resins, polyester resins and (meth) acrylic resins in that the effect of the present disclosure is large, and it is preferable to contain polyolefins. It is more preferable to contain at least one selected from the group consisting of a based resin, a rosin ester based resin, and a polyester based resin, and a polyolefin resin is particularly preferable.

The method for producing the thin film layer 1 is not particularly limited, but a composition containing a thermoplastic resin can be applied to a coating machine such as a gravure coater, a knife coater, a slot die coater, gravure printing, offset printing, screen printing, inkjet printing, or the like. The method of applying to the base material using the printing machine of the above is preferable. Of these, the method using a gravure coater is more preferable from the viewpoint of productivity. Hereinafter, the polyolefin-based resin, the rosin ester-based resin, and the polyester-based resin will be described.

<Polyolefin resin>
Examples of the polyolefin resin include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-heptene, and the like. Α-olefins having 2 to 20 carbon atoms such as 4-methyl-1-hexene, 1-octene, 4,4-dimethyl-1-hexene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, etc. , Butadiene, 1,5-hexadiene, etilidennorbornene, dicyclopentadiene and the like, homopolymers or copolymers of conjugated or non-conjugated diene having 2 to 20 carbon atoms. Further, it may be an ethylene / ethyl acrylate copolymer, an ethylene / vinyl acetate copolymer, a styrene / butadiene copolymer, a styrene / isoprene copolymer or the like. When a copolymer is used, a random copolymer, a block copolymer, or a graft copolymer can be appropriately selected. In addition, two or more of these polyolefins may be used in combination.

Preferred examples of the polyolefin resin include polypropylene, propylene / ethylene copolymer, propylene / 1-butene copolymer, propylene / ethylene / 1-butene copolymer, and propylene / ethylene / 1-octene copolymer. be able to. When the propylene copolymer is used, the propylene content is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 75% by mass or more, when the total propylene copolymer is 100% by mass. Is.

The polyolefin-based resin is preferably a modified polyolefin-based resin in that it has high adhesiveness to low-polarity materials such as polypropylene. Examples of the type of the modified polyolefin resin include acid-modified polyolefin-based resin, chlorinated polyolefin-based resin, carbodiimide-modified polyolefin-based resin, urea-modified polyolefin-based resin, and imine-modified polyolefin-based resin. These denaturations may be those in which two or more kinds of denaturations are sequentially applied. Specific examples of the modified polyolefin resin that has been sequentially modified by two or more types include an acid-modified chlorinated polyolefin resin, an acrylic-modified chlorinated polyolefin resin, and a urethane-modified chlorinated polyolefin resin. Among these, at least one selected from the group consisting of acid-modified polyolefin-based resins, chlorinated polyolefin-based resins, and acid-modified chlorinated polyolefin-based resins can be preferably used, and acid-modified polyolefin-based resins can be used. Especially preferable.

Acid-modified polyolefin resin, with respect to the polyolefin resin, preferably obtained Rukoto by graft polymerizing an unsaturated carboxylic acid or its anhydride. Conventionally known methods can be used for this modification reaction. For example, a method of adding an unsaturated carboxylic acid or an anhydride thereof to a polyolefin-based resin melted using an extruder to copolymerize the resin, or a polyolefin dissolved in a solvent. Examples thereof include a method of adding an unsaturated carboxylic acid or an anhydride thereof to a based resin and copolymerizing the resin, a method of adding an unsaturated carboxylic acid or an anhydride thereof to a polyolefin resin as a water suspension and copolymerizing the resin. Can be done. The modification site of the polyolefin chain by this modification reaction may be one end or both ends of the molecular chain, may be in the middle of the molecular chain, or may be a plurality of positions.

Examples of the unsaturated carboxylic acid or its anhydride 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 chloromalein. Unsaturated dicarboxylic acids such as acids, glutaconic acid and itaconic acid, half esters or halfamides of these unsaturated dicarboxylic acids, unsaturated tricarboxylic acids such as trans-anicot acid, maleic acid anhydride, citraconic acid anhydride, chloro Examples thereof include acid anhydrides such as maleic acid anhydride, itaconic acid anhydride, and 3,4,5,6-tetrahydrophthalic acid anhydride. Among these, (meth) acrylic acid, maleic acid and maleic anhydride are preferable, and maleic anhydride is particularly preferable.

The graft weight of maleic anhydride or the like in the acid-modified polyolefin resin is preferably 0.1 to 20% by mass, more preferably 0.5 to 10 when the total amount of the acid-modified polyolefin resin is 100% by mass. It is mass%. When the graft weight is within this range, the thin film layer 1 containing the acid-modified polyolefin resin exhibits high adhesiveness to both the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition and low-polarity materials such as polypropylene. can do.

The acid-modified polyolefin resin may be modified by using other modifying agents in combination during the modification reaction with the unsaturated carboxylic acid or its anhydride. Examples of other modifiers include (meth) acrylic acid alkyl esters, functional group-containing (meth) acrylic acid alkyl esters, aromatic vinyl compounds, cyclohexyl vinyl ethers and the like.

Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, propyl (meth) acrylic acid, butyl (meth) acrylic acid, pentyl (meth) acrylic acid, and (meth). Hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, (meth) acrylic Examples thereof include cyclohexyl acid acid. These compounds may be used alone or in combination of two or more. In the present disclosure, since the heat-resistant adhesiveness is improved, it is preferable to use a modifier further containing a (meth) acrylic acid ester having an alkyl group having 8 to 18 carbon atoms, and in particular, octyl (meth) acrylate. It preferably contains lauryl (meth) acrylate, tridecyl (meth) acrylate or stearyl (meth) acrylate.

Examples of the functional group-containing (meth) acrylic acid alkyl ester include (meth) hydroxyethyl acrylate, (meth) hydroxypropyl acrylate, (meth) glycidyl acrylate, and isocyanate-containing (meth) acrylic acid ester. .. 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 an anhydride thereof in combination as the above-mentioned modifying agent, the graft ratio by the modifying agent can be improved and the adhesiveness can be further improved.

The graft weight of the modified polyolefin resin with other modifiers is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, when the total amount of the acid-modified polyolefin resin is 100% by mass. Is. When the graft weight is within this range, the graft ratio with a denaturing agent such as maleic anhydride can be improved, and the high adhesiveness of the thin film layer 1 can be exhibited. The graft weight can be determined by a known method such as Fourier transform infrared spectroscopy.

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

It is preferable to use a modified polyolefin resin having a melting point or a softening point of 70 ° C. or higher from the viewpoint of suppressing the occurrence of shock lines in the decorative film during vacuum pressure molding and from the viewpoint of heat resistance. The melting point or softening point of the modified polyolefin resin is more preferably 80 ° C. or higher, and further preferably 90 ° C. or higher. On the other hand, if the melting point or softening point is too high, the wettability to the adherend is inferior, so that the melting point or softening point is preferably 160 ° C. or lower.

Further, instead of the acid-modified polyolefin-based resin, a copolymer incorporating a carboxylic acid and / or an acid anhydride structure in the basic skeleton of the polyolefin-based resin may be used, for example, ethylene / acrylic acid / maleic anhydride. The ternary copolymer of the above may be used.

A commercially available product may be used as the modified polyolefin resin. Specifically, the thin film layer 1 can be formed by using a commercially available modified polyolefin resin used as a plastic surface modifier, a primer for an automobile plastic base material, a primer for an electronics base material, a primer for a building material, and the like. it can. Further, the thin film layer 1 may be formed by using an adhesive composition containing a modified polyolefin resin.

Specifically, examples of the acid-modified polyolefin-based resin include Admer AT1000 and HE810 manufactured by Mitsui Chemicals, Inc., Toyotack PMA-L and PMA-T manufactured by Toyobo Co., Ltd., and the like. Examples of the chlorinated polyolefin resin include Supercron 814HS and 390S manufactured by Nippon Paper Industries, Ltd., and Hardlen 13-LP and 13-LLP manufactured by Toyobo Co., Ltd. Examples of the acid-modified chlorinated polyolefin resin include Supercron 3228S and 2319S manufactured by Nippon Paper Industries, Ltd., and Hardlen HM-21P manufactured by Toyobo Co., Ltd. Examples of the acrylic-modified chlorinated polyolefin resin include Supercron 224H and 240H manufactured by Nippon Paper Industries, Ltd. Examples of the ethylene / acrylic acid / maleic anhydride ternary copolymer include the Bondine series manufactured by Arkema. These modified polyolefin resins may be used alone or in combination of two or more. Examples of the adhesive composition containing the modified polyolefin resin include PPET-1303, PPET-1405SG, and PPET-1505SG manufactured by Toagosei Co., Ltd.

<Rosin ester resin>
Examples of the rosin ester resin include disproportionated rosin ester resin, hydrogenated rosin ester resin, and polymerized rosin ester resin. Commercially available products may be used for these, and examples of the disproportionated rosin ester resin include Superesters A-100, A-115, and A-125 manufactured by Arakawa Chemical Industries, Ltd. Examples of the hydrogenated rosin ester resin include pine crystals KE-604, KE-140 and KE-311 manufactured by Arakawa Chemical Industry Co., Ltd. Examples of the polymerized rosin ester resin include Pencell A, Pencel C, Pencel D-125, Pencel D-135 and Pencel D-160 manufactured by Arakawa Chemical Industries, Ltd.

<Polyester resin>
Examples of the polyester resin include a condensation type polymer or a copolymer having a dicarboxylic acid unit and a diol unit as constituent units.

Examples of raw materials used to form the dicarboxylic acid unit include aromatic dicarboxylic acids or their dialkyl esters or diaryl esters. Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalene 1,4-dicarboxylic acid, naphthalene 2,6-dicarboxylic acid, bis (p-carboxyphenyl) methane, anthracendicarboxylic acid, 4, Examples thereof include 4'-diphenyldicarboxylic acid and 4,4'-diphenyletherdicarboxylic acid. In addition, an aliphatic dicarboxylic acid or a dialkyl ester or diaryl ester thereof can be used in combination. Specific examples of the aliphatic dicarboxylic acid include glutaric acid, adipic acid, sebacic acid, oxalic acid, succinic acid and the like.
Specific examples of the raw materials used to form the diol unit include ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, and decamethylene. Examples thereof include glycol, 1,4-cyclohexanedimethanol, 2,2-bis (4-hydroxyphenyl) propane, polyethylene glycol, poly-1,3-propylene glycol and polytetramethylene glycol.

Among the polyester resins, a crystalline homopolyethylene terephthalate resin and a crystalline copolyester resin containing a terephthalic acid unit and / or an isophthalic acid unit as a dicarboxylic acid unit and an ethylene glycol unit as a diol unit are preferable. Further, a non-crystalline copolyester resin containing a terephthalic acid unit as a dicarboxylic acid unit and an ethylene glycol unit and a 1,4-cyclohexanedimethanol unit as a diol unit is preferable. In addition, examples of other polyester resins include polybutylene terephthalate, polyethylene-2,6-naphthalate, and biodegradable polyester resins. These polyester resins can be used alone or in admixture of two or more.

As the method for producing the polyester resin, any method is adopted, such as a so-called direct polymerization method in which a dicarboxylic acid and a diol are directly reacted, and a so-called transesterification reaction method in which a dimethyl ester of a dicarboxylic acid and a diol are transesterified. be able to.
As the polyester resin, a commercially available product may be used, or an adhesive composition containing the polyester resin may be used. Specific examples thereof include Plus Coat Z-730 manufactured by GOO CHEMICAL CO., LTD. And Byron 237, 290, 296 manufactured by Toyobo Co., Ltd. Examples of the adhesive composition containing the polyester resin include Aronmelt PES-320SK, PES-360HVXM30, and PES-310S30 manufactured by Toagosei Co., Ltd.

The melting point, softening point or Tg of the thermoplastic resin forming the thin film layer 1 is preferably 70 ° C. or higher. When the melting point, softening point or Tg of the thermoplastic resin is 70 ° C. or higher, it is preferable that the occurrence of shock lines of the decorative film can be suppressed during vacuum compressed air molding and that the heat resistance can be improved. The melting point, softening point, or Tg of the thermoplastic resin forming the thin film layer 1 is more preferably 80 ° C. or higher, and even more preferably 90 ° C. or higher. On the other hand, if the melting point, softening point or Tg is too high, the wettability to the adherend may be inferior. Therefore, it is preferable that the melting point, softening point or Tg of the thermoplastic resin is 160 ° C. or lower. The melting point and Tg of the thermoplastic resin forming the thin film layer 1 are based on JIS K7121, and the values measured by DSC at a heating rate of 10 ° C./min are adopted. For the softening point, the value of the ring-and-ball method based on JIS K6863 is adopted. However, the softening point of the rosin ester resin shall be the value of the ring and ball method based on JISK5902.

The weight average molecular weight of the thermoplastic resin forming the thin film layer 1 is preferably 3,000 to 500,000, more preferably 25,000 to 250,000. When the weight average molecular weight of the thermoplastic resin forming the thin film layer 1 is 3,000 or more, the heat resistance is good, and when it is 500,000 or less, the solubility in a solvent is improved and the handleability is excellent.
The thickness of the thin film layer 1 is not particularly limited as long as it is a layer thinner than the pressure-sensitive adhesive layer. The thickness of the thin film layer 1 is, for example, 0.01 to 50 μm, preferably 0.1 to 20 μm, and more preferably 0.3 to 15 μm as an average value of the entire thin film layer 1.

2-2. Thin film layer 2
The thin film layer 2 has an acrylic pressure-sensitive adhesive composition containing a vinyl polymer (A) and an acrylic pressure-sensitive adhesive polymer (B) having a specific glass transition temperature and a number average molecular weight in terms of exerting the effects of the present disclosure. It is particularly preferable that the product is a surface layer portion of the pressure-sensitive adhesive layer obtained by segregating the vinyl polymer (A) onto the surface layer of the pressure-sensitive adhesive layer.

3. 3. Method for manufacturing the present pressure-sensitive adhesive sheet The present pressure-sensitive adhesive sheet has a thin film layer 1 on at least one side of the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition, or constitutes a surface layer portion of the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition. It has a thin film layer 2. That is, the thin film layer 1 is provided on one or both sides of the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition, or at least one surface layer portion of the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition. Has a thin film layer 2.

As a method for producing the present pressure-sensitive adhesive sheet having the thin film layer 1, for example, the thin film layer 1 formed on a release film (hereinafter, also referred to as “separator”) is formed from the pressure-sensitive adhesive composition. By transferring to the surface, the thin film layer 1 can be formed on the surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (transfer method). Further, for example, the thin film layer 1 is formed on the surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition by overcoating the pressure-sensitive adhesive composition on the thin-film layer 1 formed on the separator. Can be done (overcoating method). Among these manufacturing methods, the recoating method is more preferable because it tends to obtain high peeling strength for the adherend and the number of peeling films used can be reduced. As a method for producing the present pressure-sensitive adhesive sheet having the thin film layer 1, the thin film layer 1 may be formed on the thin film layer 2 after the present pressure-sensitive adhesive sheet having the thin film layer 2 is prepared.

On the other hand, as a method for producing the present adhesive sheet having the thin film layer 2, a vinyl polymer (A) having a specific glass transition temperature and a number average molecular weight and an acrylic adhesive polymer (B) are contained on the separator. It is obtained by segregating the vinyl polymer (A) onto the surface layer portion of the pressure-sensitive adhesive layer by applying and forming a film of an acrylic pressure-sensitive adhesive composition. In this case, the surface layer portion functions as the thin film layer of the present disclosure.

A laminated body can be formed by heat-pressing the thin film layer side of the present adhesive sheet manufactured as described above to the adherend. When the pressure-sensitive adhesive sheet has a thin film layer on one side of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, or when the surface layer portion on one side of the pressure-sensitive adhesive layer is composed of a thin-film layer, the pressure-sensitive adhesive layer side Can also be laminated with a decorative film or the like. Further, when the present adhesive sheet has thin film layers on both sides of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, or when the surface layer portions on both sides of the pressure-sensitive adhesive layer are composed of thin film layers, the adherend. It is also possible to stack the adhesive sheets so as to sandwich them. By forming the thin film layer on the separator, it is possible to obtain an adhesive sheet with a separator in which the thin film layers are arranged adjacent to each other on the separator.

4. Decorative film and decorative molded body
4-1. Decorative film This adhesive sheet can form an adhesive layer of a decorative film. The decorative film provided with the adhesive sheet (hereinafter, also referred to as "the decorative film") exhibits high adhesiveness under high temperature conditions and can suppress the shock line of the decorative film after being attached to the base material. ..

This decorative film can include a decorative layer and a base material layer in addition to the adhesive layer described above. A decorative film having such a structure can be suitably used when the decorative molded body is attached to a molded body to obtain a decorative molded body (lamination method).

The base material layer is located on the outermost layer of the decorative molded product, which will be described later, after the decorative film is decorated on the molded product, and functions as a protective layer of the decorative molded product. The material constituting the base material layer may be any material having flexibility, and plastic is preferable. More preferably, it is a thermoplastic. The thermoplastic is not particularly limited, and examples thereof include vinyl chloride (PVC) resin, polyester resin, (meth) acrylic resin, ABS resin, polycarbonate resin, polypropylene resin, and polyethylene resin. Of these, as the material used for the base material layer, PVC resin, polyester resin, (meth) acrylic resin and 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 further preferably 100 to 300 μm. When the thickness of the base material layer is within the above range, the processability, shape followability, and handleability are improved when the decorative molded body is manufactured by the vacuum compressed air molding method.

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

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 can be secured to express a complicated design such as a gradation. An uneven pattern may be provided on the surface of the decorative film for the purpose of improving the design of the decorative film. The uneven pattern can be transferred by passing it through an embossed roller having the uneven pattern.

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

This decorative film can also be further provided with a release layer. The release layer prevents unintended adhesion and is peeled off when the decorative film is adhered to the molded product. The material constituting the release layer is not particularly limited, but for example, polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, and plastic films such as polyolefin films such as polypropylene and polyethylene; glassin paper, kraft paper and clay coated paper. Materials such as paper can be used. These thicknesses can be about 10 to 400 μm.

In addition to the above, the present decorative film may be configured to include a hard coat layer (protective layer), a decorative layer, and an adhesive layer on the release layer of the release film provided with the release layer. .. The decorative film having such a structure can be suitably used as a transfer film, and the 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 laminating method, it is necessary to remove the excess film by trimming after the decorative molding, but the transfer method does not require a trimming process, which is advantageous in terms of production efficiency.

The hard coat layer is in a tack-free state before being transferred, and after being transferred to a molded product, it is made of a material that can be cured and / or crosslinked by irradiating it with active energy rays or the like. It is preferably configured. 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 irradiated with an appropriate amount of active energy rays to make it in a semi-cured state, or active energy. Examples thereof include a linear curable resin composition in which an isocyanate compound, a polyol resin and the like are mixed and appropriately crosslinked. The thickness of the hard coat layer is not particularly limited, but can be about 1 to 50 μm, preferably about 2 to 40 μm.

4-2. Decorative Molded Body According to the present disclosure, a decorative molded body (hereinafter, also referred to as "this decorative molded body") including the present decorative film is provided. Since the decorative molded body includes a decorative film having the adhesive sheet for vacuum compressed air molding of the present disclosure, it exhibits high adhesiveness under high temperature conditions and provides a shock line of the decorative film after being attached to the base material. Can be suppressed.

The molded product to which the decorative film is adhered is not particularly limited as long as it is an article or the like to which the decorative film can be adhered. For example, resin products, metal products, ceramic products, glass products and the like. Can be mentioned. Specifically, for example, various home appliances such as household appliances, kitchen appliances, health appliances, and seasonal home appliances; housing equipment such as toilets, bathrooms, doors, and walls; automobile interiors such as bumpers, dashboards, doors, roofs, and bonnets. Goods and automobile exterior products; various miscellaneous goods such as household goods and daily necessities; electronic parts, nursing / medical supplies, ship interior / exterior products, aircraft interior / exterior products, etc.

As described above, the vacuum compressed air molding method can be used for manufacturing the present decorative molded body. In the vacuum compressed air molding method, the decorative film softened by heating under reduced pressure is brought into contact with the adherend under reduced pressure, and then the space on the opposite side of the adherend is pressed to obtain the present decorative film. Adhere while molding along the surface shape of the molded body.

5. Preferred Aspects of the Adhesive Composition As described above, the adhesive composition preferably contains an acrylic adhesive polymer (B), and contains a vinyl polymer (A) and an acrylic adhesive polymer (B). It is more preferable to contain it. Hereinafter, preferred embodiments of the vinyl polymer (A), the acrylic adhesive polymer (B), and the present pressure-sensitive adhesive layer will be described.

5-1. Vinyl polymer (A)
The vinyl polymer (A) disclosed in the present specification is preferably a polymer having a glass transition temperature (Tg) of 30 ° C. or higher and 200 ° C. or lower. The lower limit of Tg may be 40 ° C. or higher, 50 ° C. or higher, 60 ° C. or higher, or 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. Further, the range of Tg can be appropriately combined with these upper and lower limits, but is preferably, for example, 40 ° C. or higher and 180 ° C. or lower, and 60 ° C. or higher and 150 ° C. or lower. In the present specification, as the Tg of the vinyl polymer (A), a value measured at a heating rate of 10 ° C./min by differential scanning calorimetry (DSC) is adopted as Tg. If the Tg is less than 30 ° C., the Tg of the surface layer portion of the pressure-sensitive adhesive layer is unlikely to be sufficiently high, and the adhesive strength to various adherends may not be sufficient and the durability may be inferior. Further, the Tg is generally 200 ° C. or lower due to restrictions on the raw material monomer and the like.

As the monomer constituting the vinyl polymer (A), various vinyl unsaturated compounds having radical polymerizable properties can be used, and for example, a (meth) acrylic acid compound, an aromatic vinyl compound, and an unsaturated compound can be used. Carous acids, unsaturated acid anhydrides, hydroxyl group-containing unsaturated compounds, amino group-containing unsaturated compounds, amide group-containing unsaturated compounds, alkoxyl group-containing unsaturated compounds, cyano group-containing unsaturated compounds, nitrile group-containing unsaturated compounds , Maleimide-based compounds and the like. These compounds may be used alone or in combination of two or more.

Among these, it is preferable to mainly use a (meth) acrylic acid-based compound because appropriate compatibility with an acrylic-based adhesive polymer can be obtained. The specific amount of the (meth) acrylic acid-based compound used in the total monomer composition of the vinyl polymer (A) is, for example, in the range of 10% by mass or more and 100% by mass or less, and is 30% by mass or more and 95% by mass or more. It may be in the range of% or less, and may be in the range of 50% by mass or more and 90% by mass or less. The lower limit of the amount used may be 40% by mass or more, or 50% by mass or more. Further, the upper limit of the amount used may be 90% by mass or less, or 80% by mass or less.

Examples of the (meth) acrylic acid-based compound include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, n-propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, and n-butyl (meth) acrylic acid. , (Meta) isobutyl acrylate, (meth) tert-butyl acrylate, (meth) amyl acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, ethylhexyl (meth) acrylate, ( (Meta) acrylic acid alkyl esters such as n-dodecyl (meth) acrylate, n-octadecyl (meth) acrylate; cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, tert-butyl (meth) acrylate. Monopolycyclic vinyls such as cyclohexyl, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, etc. Quantities; examples include aromatic ring-based vinyl polymers such as phenyl (meth) acrylate and benzyl (meth) acrylate. These compounds may be used alone or in combination of two or more.

Among these, Tg can be set relatively high, the effect of suppressing the floating and peeling of the adhesive sheet is high, and the adhesiveness of the olefin polymer to the adherend is good. It is preferable to use an aliphatic ring-based vinyl monomer such as isobornyl acrylate, dicyclopentanyl (meth) acrylate, cyclohexyl (meth) acrylate and adamantyl (meth) acrylate. The specific amount of the aliphatic ring-based vinyl monomer used is preferably 1% by mass or more, more preferably 5% by mass or more, and 10% by mass or more, based on the total constituent monomers of the vinyl polymer (A). Is even more preferable. The upper limit of the amount of the aliphatic ring-based vinyl monomer used is preferably 90% by mass or less, more preferably 80% by mass or less, based on the total constituent monomers of the vinyl polymer (A). The range of the amount of the aliphatic ring-based vinyl monomer used is preferably 1% by mass or more and 90% by mass or less, and 5% by mass or more and 80% by mass with respect to the total constituent monomers of the vinyl polymer (A). The following is more preferable, and 10% by mass or more and 70% by mass or less is further preferable.

Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, vinyltoluene, β-methylstyrene, ethylstyrene, p-tert-butylstyrene, vinylxylene, vinylnaphthalene and the like. Can be mentioned. These compounds may be used alone or in combination of two or more. When an aromatic vinyl compound is used as the monomer constituting the vinyl polymer (A), the specific amount of the aromatic vinyl compound used is 1 with respect to all the constituent monomers of the vinyl polymer (A). The range of mass% or more and 40% by mass or less is preferable, 5% by mass or more and 30% by mass or less is more preferable, and 5% by mass or more and 20% by mass or less is further preferable.

Examples of unsaturated carboxylic acids include (meth) acrylic acid, etaclilic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, cinnamon acid, and monoalkyl esters of unsaturated dicarboxylic acids (maleic acid). , Fumaric acid, itaconic acid, 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 unsaturated acid anhydrides 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 hydroxyl group-containing unsaturated compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate. , 3-Hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, mono (meth) acrylic acid ester of polyalkylene glycol such as polyethylene glycol, 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, and ( 2- (Di-n-propylamino) ethyl (meth) acrylate, 2-dimethylaminopropyl (meth) acrylate, 2-diethylaminopropyl (meth) acrylate, 2- (di-n-propyl) (meth) acrylate Examples thereof include amino) propyl, 3-dimethylaminopropyl (meth) acrylate, 3-diethylaminopropyl (meth) acrylate, and 3- (di-n-propylamino) propyl (meth) acrylate. 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) acrylamide, and N-methylol (meth) acrylamide. These compounds may be used alone or in combination of two or more.

Examples of the alkoxyl group-containing unsaturated compound include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (n-propoxy) ethyl (n-propoxy), and (meth) acrylic acid. 2- (N-butoxy) ethyl, (meth) acrylate 3-methoxypropyl, (meth) acrylate 3-ethoxypropyl, (meth) acrylate 2- (n-propoxy) propyl, (meth) acrylate 2- (N-Butoxy) propyl and the like can be mentioned. 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. 2-cyanopropyl acid, 3-cyanopropyl (meth) acrylate, 4-cyanobutyl (meth) acrylate, 6-cyanohexyl (meth) acrylate, 2-ethyl-6-cyanohexyl (meth) acrylate, ( Meta) Examples thereof include 8-cyanooctyl acrylate. These compounds may be used alone or in combination of two or more.

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

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

In addition to the above compounds, unsaturated dicarboxylic acid dialkyl esters, vinyl ester compounds, vinyl ether compounds and the like can also be used. Examples of the dialkyl ester of the 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 cinnate 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, vinyl cyclohexyl ether and the like.

The number average molecular weight (Mn) of the vinyl polymer (A) can be 500 or more and 10,000 or less. The Mn of the vinyl polymer (A) is preferably 500 or more, more preferably 1,000 or more, and even more preferably 2,000 or more. The upper limit of Mn of the vinyl polymer (A) is preferably 10,000 or less, more preferably 8,000 or less, and further preferably 7,000 or less. Mn may be 500 or more and 7,000 or less, and may be 1,000 or more and 5,000 or less. If Mn exceeds 10,000, the compatibility with the acrylic adhesive polymer (B) may deteriorate. On the other hand, in order to produce a polymer having a Mn of less than 500, it may be necessary to use a large amount of a polymerization initiator or a chain transfer agent, or a decrease in productivity may occur.

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

The vinyl polymer (A) is not particularly limited in its production method, but can be easily obtained by polymerizing the above-mentioned monomer by adopting a known radical polymerization method such as a solution polymerization method. .. In the case of the solution polymerization method, an organic solvent and a vinyl monomer raw material are charged into a reactor, a thermal polymerization initiator such as an organic peroxide or an azo compound is added, and the mixture is heated to 50 to 300 ° C. for copolymerization. This makes it possible to obtain the desired vinyl polymer. The vinyl polymer may be used as a solution dissolved in an organic solvent, or the solvent may be distilled off by heat and decompression treatment or the like.

The method for charging each raw material containing a monomer may be a batch-type initial batch preparation in which all raw materials are collectively charged, or a semi-continuous preparation in which at least one raw material is continuously supplied into the reactor. A continuous polymerization method may be used in which the raw materials are continuously supplied and the produced resin is continuously extracted from the reactor at the same time.

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

The initiator used in the present specification may be an azo compound, an organic peroxide, an inorganic peroxide, or the like, but is not particularly limited. A redox-type polymerization initiator composed of a known oxidizing agent and reducing agent may be used. In addition, a known chain transfer agent can also be used in combination.

Examples of the azo compound include 2,2'-azobis (isobutyronitrile), 1,1-azobis (cyclohexane-1-carbonitrile), azocoumen, 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, and 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane. , 1,1-bis (tert-butylperoxy) cyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, cumenehydroperoxide, 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 -Butyl cumyl peroxide, decanoyyl 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 can be mentioned.
Examples of the inorganic peroxide include potassium persulfate, sodium persulfate, ammonium persulfate and the like.

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 persulfate, hydrogen peroxide, and tert-butyl hydroper. Those using oxide or the like as an oxidizing agent can be used.

In order to adjust the molecular weight of the vinyl polymer (A), a known chain transfer agent may be used if necessary. Chain transfer agents include ethanethiol, butanethiol, dodecanethiol, benzenethiol, toluenethiol, α-toluenethiol, phenethylmercaptan, mercaptoethanol, 3-mercaptopropanol, thioglycerin, thioglycolic acid, 2-mercaptopropionic acid, 3-Mercaptopropionic acid, α-mercaptoisobutyric acid, methyl mercaptopropionate, ethyl mercaptopropionate, thioacetic acid, thioalic acid, thiosalicylic acid, octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, n-hexadecil mercaptan Examples thereof include n-tetradecyl mercaptan and tert-tetradecyl mercaptan.

The vinyl polymer (A) can also be obtained by continuously polymerizing in a temperature range of 180 to 350 ° C. using a stirring tank type reactor. In this polymerization method, a relatively low molecular weight vinyl polymer can be obtained without substantially using a polymerization initiator or a chain transfer agent, so that a high-purity polymer can be obtained, and the points of coloring and odor described later can be obtained. However, it is preferable because it is advantageous. When the polymerization temperature is less than 180 ° C., a polymerization initiator and a large amount of chain transfer agent are required for the polymerization reaction, and the obtained copolymer is easily colored and generates an unfavorable odor. On the other hand, when the polymerization temperature exceeds 350 ° C., a decomposition reaction is likely to occur during the polymerization reaction, and the obtained copolymer is colored. Therefore, the transparency of the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition containing the copolymer is high. There is concern about a decline. Further, according to such a polymerization method, a vinyl polymer having a small molecular weight distribution range can be obtained. The polymerization initiator may be used arbitrarily, but it is preferably used in an amount of about 1% by mass or less based on all the monomers.

5-2. Acrylic adhesive polymer (B)
The acrylic adhesive polymer (B) disclosed in the present specification is a polymer containing (meth) acrylic acid esters as a main constituent unit. Examples of the acrylic adhesive polymer (B) include an acrylic random copolymer and an acrylic block copolymer.

<About acrylic random copolymer>
When the acrylic adhesive polymer (B) is a random copolymer, the acrylic adhesive polymer (B) has a glass transition temperature (Tg) of, for example, -80 ° C or higher and 10 ° C or lower. It is a polymer having. 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. Further, the range of Tg can be appropriately combined with these upper and lower limits, but is preferably in the range of −70 ° C. or higher and 0 ° C. or lower, and for example, −60 ° C. or higher and −10 ° C. or lower. Further, for example, it is −50 ° C. or higher and −20 ° C. or lower. When Tg is −80 ° C. or higher, a pressure-sensitive adhesive having sufficient cohesive force and good adhesiveness can be obtained. Further, when Tg is 10 ° C. or lower, good step followability can be provided. The Tg of the acrylic adhesive polymer (B) is a value measured by DSC at a heating rate of 10 ° C./min.

Further, the weight average molecular weight (Mw) of the acrylic adhesive polymer (B) is preferably 100,000 or more from the viewpoint of exhibiting sufficient cohesive force and good adhesiveness. The lower limit of Mw may be 300,000 or more, 400,000 or more, or 500,000 or more. Further, when Mw is 400,000 or more, heat resistance is further improved, which is preferable. On the other hand, if Mw is too large, the step followability tends to decrease, and it may be difficult to handle in manufacturing. Therefore, the upper limit of Mw is preferably 5,000,000 or less. The upper limit of Mw may be 3,000,000 or less, 2,000,000 or less, or 1,000,000 or less.

The number average molecular weight (Mn) of the acrylic adhesive polymer (B) is preferably 30,000 or more from the viewpoint of exhibiting sufficient cohesive force and good adhesiveness. The lower limit of Mn may be 40,000 or more, 50,000 or more, or 60,000 or more. The upper limit of Mn is preferably 3,000,000 or less in order to ensure good step followability. The upper limit of Mn may be 1,000,000 or less, or 800,000 or less.

Further, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is, for example, 6.0 or less from the viewpoint that good adhesive strength can be easily obtained. Mw / Mn may be 5.0 or less, 4.7 or less, 4.5 or less, 4.0 or less, or 3.8 or less. It may be 3.6 or less. The weight average molecular weight Mw and the number average molecular weight Mn are standard polystyrene-equivalent values obtained by using gel permeation chromatography (GPC).

As the monomer constituting the acrylic adhesive polymer (B), an alkyl (meth) acrylic acid having an alkyl group having 1 to 12 carbon atoms can be obtained in that an acrylic copolymer having good adhesiveness can be obtained. Examples thereof include esters and (meth) acrylic acid alkoxyalkyl esters having an alkoxyalkyl group having 2 to 12 carbon atoms. As the monomer constituting the acrylic adhesive polymer (B), one or more of these can be used.

Examples of the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 12 carbon atoms include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, isopropyl (meth) acrylic acid, and n- (meth) acrylic acid. Butyl, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n- (meth) acrylate Nonyl, isononyl (meth) acrylate, n-decyl (meth) acrylate, lauryl (meth) acrylate and the like can be mentioned, and preferred monomers include n-butyl (meth) acrylate and 2 (meth) acrylate. -Ethylhexyl, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate and the like can be mentioned.

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

The amount of the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 12 carbon atoms and / or the (meth) acrylic acid alkoxyalkyl ester having an alkoxyalkyl group having 2 to 12 carbon atoms is not particularly limited. However, in that good adhesive performance tends to be obtained, the lower limit thereof can be 10% by mass or more based on the total constituent monomers of the acrylic copolymer, and 20% by mass or more. It may be 30% by mass or more, 40% by mass or more, or 50% by mass or more. The upper limit thereof is 100% by mass or less, 99% by mass or less, 95% by mass or less, 90% by mass or less, or 80% by mass or less. May be good. The range of the amount used can be set by appropriately combining these upper and lower limits. For example, it is 10% by mass or more and 100% by mass or less, 10% by mass or more and 99% by mass or less, 20% by mass or more and 95% by mass or less. Further, for example, it can be 30% by mass or more and 90% by mass or less. When it is 10% by mass or more, it is preferable in that a pressure-sensitive adhesive composition having good adhesive strength, initial adhesive strength (tack), low-temperature adhesiveness and the like can be obtained.

Among the above, (meth) acrylic acid alkyl esters having an alkyl group having 1 to 3 carbon atoms can be used. By using such a (meth) acrylic acid alkyl ester, the elastic modulus of Tg of the acrylic adhesive polymer (B) and the pressure-sensitive adhesive layer described later can be improved, which is advantageous for improving the heat resistance of the pressure-sensitive adhesive layer. .. A (meth) acrylic acid alkyl ester having an alkyl group having 1 to 2 carbon atoms is preferable, and methyl (meth) acrylate is more preferable.

The acrylic adhesive polymer (B) is other than the above-mentioned (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester, and other single amounts copolymerizable with these as long as the adhesiveness is not impaired. You can use the body.

Examples of other vinyl-based monomers include α, β-ethylene unsaturated carboxylic acid monomers such as (meth) acrylic acid, itaconic acid, maleic acid, and fumaric acid; styrene, α-methylstyrene, and vinyl. Aromatic vinyl monomers such as toluene; cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate Ordicyclic vinyl monomers such as; monoalkyl esters of unsaturated dicarboxylic acids such as itaconic acid monoethyl ester and fumaric acid monobutyl ester; 2-hydroxyethyl (meth) acrylic acid, 3-hydroxyethyl (meth) acrylic acid. Hydroxyl group-containing vinyl monomers such as hydroxypropyl, 4-hydroxybutyl (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate and polyethylene-polypropylene glycol mono (meth) acrylate; acrylamide, N-methylol. Ethylene-based unsaturated carboxylic acid amides such as acrylamide, N-methoxymethyl acrylamide, N-methoxybutyl acrylamide and N-substituted compounds; unsaturated alcohols such as allyl alcohol; (meth) acrylonitrile, vinyl acetate, glycidyl (meth) acrylate , Diacetone acrylamide and the like, and one or more of these can be used.

When an α, β-ethylenically unsaturated carboxylic acid monomer is used, the obtained pressure-sensitive adhesive composition is preferable from the viewpoint of increasing the adhesive strength to an adherend such as glass, metal, or ABS plate. When α, β-ethylenically unsaturated carboxylic acid monomer is used, the amount of α, β-ethylenically unsaturated carboxylic acid monomer used is based on all the constituent monomers of the acrylic copolymer. It is preferably 1% by mass or more and 20% by mass or less, more preferably 2% by mass or more and 15% by mass or less, and further preferably 3% by mass or more and 10% by mass or less. When the amount used is 1% by mass or more, the effect of improving the adhesive force to the adherend can be obtained, and when it is 20% by mass or less, good adhesiveness is maintained. As the α, β-ethylenically unsaturated carboxylic acid monomer, one kind or two or more kinds may be used. From the viewpoint of polymerizable property, (meth) acrylic acid is preferable.

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. The polyfunctional polymerizable monomer also acts as a so-called cross-linking agent, and by using this, a cross-linked structure can be formed in the present adhesive polymer.

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 (meth) acrylate. Di (meth) acrylates of dihydric alcohols such as meta) acrylate; trimethylol propantri (meth) acrylate, tri (meth) acrylate of trimethyl propanethylene oxide modified product, glycerin tri (meth) acrylate, pentaerythritol tri (meth) Examples thereof include tri (meth) acrylates of trivalent or higher valent alcohols such as meta) acrylates and pentaerythritol tetra (meth) acrylates, and poly (meth) acrylates such as tetra (meth) acrylates.

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; polyfunctional vinyl compounds such as divinylbenzene and the like can be mentioned.

Compounds having both (meth) acryloyl group and alkenyl group include allyl (meth) acrylate, isopropenyl (meth) acrylate, butenyl (meth) acrylate, pentenyl (meth) acrylate, and (meth) acrylate. 2- (2-Vinyloxyethoxy) ethyl and the like can be mentioned.

The acrylic adhesive polymer (B) can also be obtained by a known radical polymerization method such as a solution polymerization method, a suspension polymerization method, or an emulsion polymerization method. Further, as the acrylic adhesive polymer (B), a commercially available product may be used. Examples of the commercially available products include SK Dyne 2950, 2953 and 2943H manufactured by Soken Chemical Co., Ltd., and Corponil 8711 and N-2411TF manufactured by Nippon Synthetic Chemistry Co., Ltd.

In addition, the acrylic adhesive polymer (B) can also be obtained from the 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 residue of the acrylic adhesive polymer (B). can do. Acrylic adhesive polymer (B) can be obtained 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.

<About acrylic block copolymers>
When the acrylic adhesive polymer (B) is an acrylic block copolymer (hereinafter referred to as "the block copolymer"), the block copolymer is a polymer block (a) and a (meth) acrylic. It is preferable to have one or more polymer blocks (b) each. The block copolymer is, for example, a (ab) diblock polymer composed of a polymer block (a) and a (meth) acrylic polymer block (b), or a polymer block (a) / (meth) acrylic polymer. (Aba) triblock composed of block (b) / polymer block (a) or (meth) acrylic polymer block (b) / polymer block (a) / (meth) acrylic polymer block (b) ) (Bab) triblock and the like. Further, it may have a structure such as (abc) or (abca) containing a polymer block (c) other than the polymer block (a) and the (meth) acrylic polymer block (b). Above all, 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 suitable from the viewpoint of adhesive physical properties. The a- (ba) n structure may be present in all or part of the copolymer, and may be, for example, a copolymer having a (babab) structure.
Here, with respect to the glass transition point of this block copolymer, an inflection point corresponding to each polymer block can be obtained by performing differential scanning calorimetry, and the Tg of each polymer block can be obtained from these inflection points. it can. In the present disclosure, the Tg of the block copolymer means the Tg of the polymer block (more specifically, the acrylic polymer block (b)) which is the main component.

(Polymer block (a))
The polymer block (a) of this block copolymer can be a block having a structural unit derived from at least one monomer selected from the group consisting of a maleimide compound and an amide group-containing vinyl compound.

Maleimide compounds include maleimide and N-substituted maleimide compounds. Examples of the N-substituted maleimide compound include N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, N-isopropylmaleimide, Nn-butylmaleimide, N-isobutylmaleimide, and N-tert-butylmaleimide. N-alkyl-substituted maleimide compounds such as N-pentylmaleimide, N-hexylmaleimide, N-heptylmaleimide, N-octylmaleimide, N-laurylmaleimide, N-stearylmaleimide; N-cyclopentylmaleimide, N-cyclohexylmaleimide and the like. N-Cycloalkyl-substituted maleimide compounds; N-phenylmaleimide, N- (4-hydroxyphenyl) maleimide, N- (4-acetylphenyl) maleimide, N- (4-methoxyphenyl) maleimide, N- (4-ethoxyphenyl) ) N-aryl or N-aralkyl-substituted maleimide compounds such as maleimide, N- (4-chlorophenyl) maleimide, N- (4-bromophenyl) maleimide, N-benzylmaleimide, etc., and one of them or Two or more types 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). Among the above, the polymer block (a) is preferably a compound represented by the following general formula (1) in that the obtained block copolymer has better heat resistance and adhesiveness.

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

Examples of the amide group-containing vinyl compound include (meth) acrylamide, tert-butyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, and N-isopropyl (meth) acrylamide. , N, N-Dimethylaminopropyl (meth) acrylamide, (meth) acryloylmorpholin and other (meth) acrylamide derivatives; N-vinylamide-based monomers such as N-vinylacetamide, N-vinylformamide and N-vinylisobutylamide. Etc., 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).

In the polymer block (a), the structural unit derived from at least one selected from the group consisting of the maleimide compound and the amide group-containing vinyl compound is 10% by mass with respect to all the structural units of the polymer block (a). It can be 100% by mass or less. Such a structural unit is, 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, and for example, 50% by mass or more, and also. For example, it is 60% by mass or more. The structural unit derived from at least one selected from the group consisting of the maleimide compound and the amide group-containing vinyl compound is, for example, 99% by mass or less, for example 90% by mass or less, and 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 at least one selected from the group consisting of maleimide compounds and amide group-containing vinyl compounds is less than 10% by mass, the heat resistance, durability and peeling resistance of the obtained block copolymer are not sufficient. There are times.

The polymer block (a) can be a block having a structural unit derived from an aromatic vinyl monomer. Aromatic vinyl monomers include styrene and its derivatives. Specific compounds include, for example, styrene, α-methylstyrene, β-methylstyrene, vinylxylene, vinylnaphthalene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethyl. Styrene, p-ethylstyrene, pn-butylstyrene, p-isobutylstyrene, pt-butylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-chloromethylstyrene, p-chloro Examples thereof include methylstyrene, o-chlorostyrene, p-chlorostyrene, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, divinylbenzene and the like, and one or more of these can be used. .. By polymerizing a monomer containing an aromatic vinyl monomer, a structural unit derived from the aromatic vinyl monomer can be introduced into the polymer block (a).

Among the above, from the viewpoint of polymerizability, the aromatic vinyl monomers constituting the polymer block (a) are styrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, and o-hydroxystyrene. , M-Hydroxystyrene, p-hydroxystyrene are preferable. 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.

In the polymer block (a), the structural unit derived from the aromatic vinyl monomer can be 1% by mass or more and 70% by mass or less with respect to all the structural units of the polymer block (a). Such a structural unit is, for example, 5% by mass or more, for example, 10% by mass or more, and for example, 20% by mass or more. The structural unit derived from the aromatic vinyl monomer is, for example, 60% by mass or less, for example, 50% by mass or less, and for example, 40% by mass or less. When the structural unit derived from the aromatic vinyl monomer is 1% by mass or more, the polymerizable property of the maleimide compound can be particularly improved. On the other hand, if it is 70% by mass or less, it is possible to secure the required amount of the structural unit derived from the maleimide compound and / or the amide group-containing vinyl compound, so that both blocks having excellent heat resistance, durability and peeling resistance can be secured. A polymer can be obtained.

Further, the polymer block (a) may be a block containing a structural unit derived from a vinyl-based monomer having a crosslinkable functional group (hereinafter, also referred to as “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. It may be introduced.

The vinyl-based monomer having a crosslinkable functional group is not particularly limited, and various known monomer compounds can be used. Examples of the vinyl-based monomer having a crosslinkable functional group include α, β-ethylenic unsaturated carboxylic acid monomer, unsaturated acid anhydride monomer, hydroxyl group-containing vinyl monomer, and epoxy group-containing vinyl. Examples thereof include a monomer, a primary or secondary amino group-containing vinyl monomer, and a reactive silicon group-containing vinyl monomer. In the production of the polymer block (a), one or a combination of two or more known compounds can be used as the vinyl-based monomer having a crosslinkable functional group.

Examples of the α, β-ethylenically unsaturated carboxylic acid monomer include (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, and cinnamic acid. These compounds may be used alone or in combination of two or more. Examples of the unsaturated acid anhydride monomer 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 hydroxyl group-containing vinyl monomer include hydroxyl group-containing vinyl monomers exemplified as other monomers of the acrylic adhesive polymer (B).

Examples of the epoxy group-containing vinyl monomer 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 primary or secondary amino group-containing vinyl monomer include aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, N-methylaminoethyl (meth) acrylate, and N-ethylaminoethyl (meth) acrylate. Amino group-containing (meth) acrylic acid ester; Amino group-containing (meth) acrylamide such as aminoethyl (meth) acrylamide, aminopropyl (meth) acrylamide, N-methylaminoethyl (meth) acrylamide, and N-ethylaminoethyl (meth) acrylamide. ) Ethyl and the like can be mentioned.

Examples of the reactive silicon group-containing vinyl monomer include vinylsilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, and vinyldimethylmethoxysilanen; trimethoxysilylpropyl (meth) acrylate, (meth). Cyril group-containing (meth) acrylic acid esters such as triethoxysilylpropyl acrylate, methyldimethoxysilylpropyl (meth) acrylate, and dimethylmethoxysilylpropyl (meth) acrylate; silyl group-containing vinyl ethers such as trimethoxysilylpropyl vinyl ether. Kind: Cyril group-containing vinyl esters such as trimethoxysilyl undecanoate vinyl and the like. These compounds may be used alone or in combination of two or more. A reactive silicon group-containing vinyl monomer is suitable because two or more crosslinkable functional groups can be easily introduced. Further, in such a vinyl monomer, reactive silicon groups can be dehydrated and condensed (polymerized). Therefore, it is preferable in that the polymerization reaction for producing a block copolymer and the subsequent cross-linking reaction can be efficiently performed.

In addition to the above, by copolymerizing the oxazoline group-containing vinyl monomer and / or the isocyanate group-containing vinyl monomer, the oxazoline group and / or the isocyanate group can be formed into the polymer block (a) as a crosslinkable functional group. Can be introduced.

Further, by copolymerizing a polyfunctional polymerizable monomer having two or more polymerizable unsaturated groups in the molecule, a polymerizable unsaturated group is introduced into the polymer block (a) as a crosslinkable functional group. 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 the molecule, and is a polyfunctional (meth) acrylate compound, a polyfunctional alkenyl compound, and the like. Examples thereof include compounds having both (meth) acryloyl group and alkenyl group. For example, in addition to alkylenediol diacrylates such as hexanediol diacrylate, allyl (meth) acrylate, isopropenyl (meth) acrylate, butenyl (meth) acrylate, pentenyl (meth) acrylate, (meth) acrylate 2 Examples thereof include compounds having both a (meth) acryloyl group and an alkenyl group in the molecule, such as-(2-vinyloxyethoxy) ethyl. These compounds may be used alone or in combination of two or more.

When the polymer block (a) has a crosslinkable structural unit, for example, 0.01% by mass or more of the crosslinkable structural unit can be provided with respect to all the structural units of the polymer block (a). The content of the crosslinkable structural unit is, for example, 0.1% by mass or more, for example, 1.0% by mass or more, and for example, 2.0% by mass or more. By providing 0.01% by mass or more of the crosslinkable structural unit, it becomes easy to obtain a good crosslinked structure, and it becomes easy to obtain a block copolymer having high heat resistance and durability. The upper limit of the content of the crosslinkable structural unit is not particularly limited, but from the viewpoint of controllability of the crosslinking reaction, it is, for example, 60% by mass or less, for example, 40% by mass or less, and for example, 20% by mass. % Or less, and for example, 10% by mass or less. The range of the content of the crosslinkable structural unit can be appropriately combined with the above-mentioned lower limit and upper limit, and for example, 1% by mass or more and 60% by mass or less, for example, 5% by mass or more and 50% by mass or less, 10% by mass. It can be 40% by mass or less.

The polymer block (a) may also include a structural unit derived from another monomer copolymerizable with these monomers as long as the action of the block copolymer is not impaired. The other monomer can include, for example, a (meth) acrylic acid alkyl ester, a (meth) acrylic acid alkoxyalkyl ester, an aliphatic ring-based vinyl monomer of (meth) acrylic acid, and the like. These compounds may be used alone or in combination of two or more. Specific examples of the (meth) acrylic acid alkyl ester, the (meth) acrylic acid alkoxyalkyl ester, and the aliphatic ring-based vinyl monomer can be used in the production of the acrylic adhesive polymer (B). Examples thereof include acid alkyl esters, (meth) acrylic acid alkoxyalkyl esters, and aliphatic ring-based vinyl monomers.

Examples of the monomer other than the above include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl (meth) acrylate.
In the polymer block (a), the proportion of the structural units derived from the other monomers is, for example, in the range of 0% by mass or more and 50% by mass or less with respect to all the structural units of the polymer block (a). Can be. Further, the proportion of the constituent units derived from the other monomers is, for example, 5% by mass or more, and for example, 10% by mass or more. Further, the proportion of the constituent units derived from the other monomers is, for example, 45% by mass or less, and for example, 40% by mass or less.

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

In this specification, the glass transition points of the polymer block (a) and the (meth) acrylic polymer block (b) as well as the block copolymer are measured by differential scanning calorimetry as described in Examples described later. It can be measured by (DSC). When DSC is not possible, it can be calculated from the monomer units constituting the polymer block.

(Phase separation)
The polymer block (a) preferably has a property of phase separation from the (meth) acrylic polymer block (b). By having such a property, a microphase separated structure can be formed. A person skilled in the art can easily design a block that is phase-separated from the (meth) acrylic polymer block (b) based on the common general knowledge as of the filing of the present application. For example, when the SP value of the polymer block (a) calculated by a known dissolution parameter calculation method, for example, the Fedors method shown below, is compared with the SP value of the (meth) acrylic polymer block (b). The difference can be 0.01 (absolute value) or more. Further, the difference may be, for example, 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 (meth) acrylic polymer block (b) is prepared, and the structure obtained by mixing these is obtained by using an electron microscope, an atomic force microscope, or a small angle X-ray. By observing with line scattering or the like, the phase separation between blocks can be easily estimated.

The SP value is R. F. It can be calculated by the calculation method described in "Polymer Engineering and Science" 14 (2), 147 (1974) written by Fedors. Specifically, the calculation method shown in the equation (2) is used.

(However, in mathematical formula (2), δ, ΔEvap and V are as follows.
δ: SP value ((cal / cm ³ ) ^1/2 )
ΔEvap: Molar heat of vaporization of each atomic group (cal / mol)
V: Molar volume of each atomic group (cm ³ / mol))

((Meta) acrylic polymer block (b))
The (meth) acrylic polymer block (b) of this block copolymer is a polymer block having a structural unit derived from the (meth) acrylic monomer, and is represented by the following general formula (3). It can be a block having at least one selected from the above compounds as a constituent unit. Examples of the compound represented by the general formula (3) include (meth) acrylic acid alkyl ester, (meth) acrylic acid alkoxyalkyl ester, and polyalkylene glycol mono (meth) acrylate.
CH ₂ = CR ^3- C (= O) O- (R ⁴ O) _n- R ⁵ (3)
(In the formula (3), R ³ represents a hydrogen or a methyl group, R ⁴ represents a linear or branched alkylene group having 2 to 6 carbon atoms, and R ⁵ represents a hydrogen or an alkyl group having 1 to 20 carbon atoms. Alternatively, it represents an aryl group having 6 to 20 carbon atoms. N represents an integer of 0 or 1 to 100.)

As the (meth) acrylic acid alkyl ester and the (meth) acrylic acid alkoxyalkyl ester, the (meth) acrylic acid alkyl ester and the (meth) acrylic acid alkoxyalkyl ester that can be used in the production of the acrylic adhesive polymer (B) can be used. Can be mentioned.

The polyalkylene glycol mono (meth) acrylate, the general formula in (3) (R 4 ^O) is may be only one kind, may include two or more types of structural units. If a (R 4 ^O) of two or more, n represents represents the total number of repeating units 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-polyethylene glycol mono (meth) acrylate, polyethylene glycol-polytetraethylene glycol mono (meth) acrylate, and methoxypolyethylene glycol. Mono (meth) acrylate, lauroxypolyethylene glycol mono (meth) acrylate, stearoxypolyethylene glycol mono (meth) acrylate, octoxypolyethylene glycol-polypropylene glycol mono (meth) acrylate, phenoxypolyethylene glycol mono (meth) acrylate, phenoxypolyethylene Glycol-polyethylene glycol mono (meth) acrylate, nonylphenoxy polyethylene glycol mono (meth) acrylate, nonylphenoxypolyethylene glycol mono (meth) acrylate, nonylphenoxypolyethylene glycol-polypropylene glycol mono (meth) acrylate and the like can be mentioned. The above compounds are also available as commercial products. For example, examples of the methoxypolyethylene glycol monomethacrylate include "Blemmer PME series" (n = 2, 4, 9, 23, 90, etc., Blemmer is a registered trademark). In addition, a (meth) acrylic acid ester compound having a functional group such as an amide group, an amino group, a carboxy group and a hydroxy group can also be used.

Among the above, the (meth) acrylic polymer block (b) has an alkyl group having 1 to 12 carbon atoms or an alkoxyalkyl having 2 to 8 carbon atoms in that a block copolymer having excellent flexibility can be obtained. It is preferable to have a structural unit derived from an acrylic acid alkyl ester compound having a group. Further, from the viewpoint of adhesive performance, the (meth) acrylic polymer block (b) is an acrylic acid alkyl ester compound having an alkyl group having 1 to 8 carbon atoms or an alkoxyalkyl group having 2 to 3 carbon atoms. It is more preferable that it contains a structural unit from which it is derived.

In the (meth) acrylic polymer block (b), the structural units derived from the compound represented by the general formula (3) are used with respect to all the structural units of the (meth) acrylic polymer block (b). It can be 20% by mass or more and 100% by mass or less. Such a structural 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 structural unit is in the above range, a block copolymer that is good in terms of adhesive properties tends to be obtained. When 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 (3) as the main constituent monomer. It becomes a block to do.

Further, 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% by mass of the crosslinkable structural unit is added to all the structural units of the (meth) acrylic polymer block (b). The above can be provided. The content of the crosslinkable structural unit is, for example, 0.1% by mass or more, and for example, 0.5% by mass or more. By setting the introduction amount of the crosslinkable structural unit to 0.01% by mass or more, it becomes easy to obtain a block copolymer having excellent heat resistance. The upper limit of the content of the crosslinkable structural unit is not particularly limited, but from the viewpoint of flexibility, it is, for example, 20% by mass or less, for example, 10% by mass or less, and for example, 8% by mass or less. is there. As for the range of the crosslinkable structural unit, the lower limit and the upper limit described above can be appropriately combined, and for example, 0.01 mass% or more and 20 mass% or less, for example, 0.1 mass% or more and 10 mass% or less, 0. It can be 5% by mass or more and 8% by mass or less.

As long as the effects produced by the present disclosure are not impaired, the (meth) acrylic polymer block (b) shall use a monomer other than the above (meth) acrylic monomer as a constituent monomer unit. Can be done. As the monomer other than the (meth) acrylic monomer, a monomer having an unsaturated group other than the (meth) acryloyl group can be used. Specific examples thereof include aliphatic or aromatic vinyl compounds such as alkyl vinyl esters, alkyl vinyl ethers and styrenes.

(Glass-transition temperature)
The glass transition temperature (Tg) of the (meth) acrylic polymer block (b) is preferably 10 ° C. or lower. The Tg of the (meth) acrylic polymer block (b) can contribute to the adhesiveness of the block copolymer. Therefore, when Tg is 10 ° C. or lower, better adhesiveness can be imparted to the block copolymer. The Tg of the (meth) acrylic polymer block (b) is, for example, 0 ° C. or lower, for example, −5 ° C. or lower, for example, −10 ° C. or lower, and for example, −20 ° C. or lower. Also, for example, -25 ° C or lower, and for example, -30 ° C or lower. The lower limit of Tg of the (meth) acrylic polymer block (b) is, for example, −80 ° C. or higher.

(Phase separation)
As described above, the (meth) acrylic polymer block (b) preferably has a property of phase separation from the polymer block (a), and a predetermined difference from the SP value of the polymer block (a) can be obtained. It is preferable to have.

This block copolymer is not particularly limited as long as a block copolymer having the polymer block (a) and the (meth) acrylic polymer block (b) is obtained, and a known production method is adopted. can do. For example, a method using various controlled polymerization methods such as living radical polymerization and living anionic polymerization, a method of coupling polymers having functional groups, and the like can be mentioned. Among these, the living radical polymerization method is preferable from the viewpoint of simple operation and applicability to a wide range of monomers.

There are no particular restrictions on the type of living radical polymerization method, such as reversible addition-cleavage chain transfer polymerization method (RAFT method), nitroxy radical method (NMP method), atom transfer radical polymerization method (ATRP method), and organic tellurium compounds. Various polymerization methods such as a polymerization method using (TERP method), 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 can be adopted. Among these, the RAFT method, the NMP method and the ATRP method are preferable from the viewpoint of controllability of polymerization and ease of implementation.

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

As the polymerization initiator used in the polymerization by the RAFT method, known radical polymerization initiators such as azo compounds, organic peroxides and persulfates can be used, but they are easy to handle and are secondary to the radical polymerization. Azo compounds are preferable because the reaction is unlikely to occur. Specific examples of the azo compound include those described above. Only one kind of the radical polymerization initiator may be used, or two or more kinds thereof may be used in combination.

The ratio of the radical polymerization initiator used is not particularly limited, but the amount of the radical polymerization initiator used per 1 part by mass of the RAFT agent is preferably 0.5 parts by mass or less from the viewpoint of obtaining a polymer having a smaller molecular weight distribution. , 0.3 parts by mass 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 used with respect to 1 part by mass of the RAFT agent is preferably 0.01 part by mass or more. Therefore, the amount of the radical polymerization initiator used with respect to 1 part by mass of the RAFT agent is preferably in the range of 0.01 to 0.5 parts by mass, and more preferably in the range of 0.05 to 0.3 parts by mass.

The reaction temperature during the polymerization reaction by the RAFT method is preferably 40 ° C. or higher and 100 ° C. or lower, more preferably 45 ° C. or higher and 90 ° C. or lower, and further preferably 50 ° C. or higher and 80 ° C. or lower. When the reaction temperature is 40 ° C. or higher, 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 initiators and solvents that can be used are relaxed.

In the NMP method, a specific alkoxyamine compound or the like having nitroxide is used as a living radical polymerization initiator, and the polymerization proceeds via the nitroxide radical derived from this. 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 polymerization controllability when polymerizing a monomer containing an acrylate, it is preferable to use a compound represented by the general formula (4) as the nitroxide compound.

(In the formula (4), R ⁶ is an alkyl group or a hydrogen atom having 1 to 2 carbon atoms, R ⁷ is an alkyl group or a nitrile group having 1 to 2 carbon atoms, and R ⁸ is − (CH ₂ ) m. -, M is 0 to 2, and R ⁹ and R ¹⁰ are alkyl groups having 1 to 4 carbon atoms.)

The nitroxide compound represented by the above general formula (4) undergoes a primary dissociation by heating at about 70 to 80 ° C. and causes an addition reaction with a vinyl-based monomer. At this time, a polyfunctional polymerization precursor can be obtained by adding a nitroxide compound to a vinyl-based monomer having two or more vinyl groups. Next, the vinyl-based 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 used is appropriately adjusted depending on the monomer used, the type of the nitroxide compound, and the like.

When this block copolymer is produced by the NMP method, 0.001 to 0.2 mol of the nitroxide radical represented by the following general formula (5) is added to 1 mol of the nitroxide compound represented by the above general formula (4). It may be added in a range and polymerized.

(In formula (5), R ¹¹ and R ¹² are alkyl groups having 1 to 4 carbon atoms.)

By adding 0.001 mol or more of the nitroxide radical represented by the above general formula (5), the time for the concentration of the nitroxide radical to reach a steady state is shortened. 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 added is too large, the polymerization may not proceed. A more preferable amount of the nitroxide radical added to 1 mol of the nitroxide compound is in the range of 0.01 to 0.5 mol, and a more preferable amount of addition is in the range of 0.05 to 0.2 mol.

The reaction temperature in the NMP method is preferably 50 ° C. or higher and 140 ° C. or lower, more preferably 60 ° C. or higher and 130 ° C. or lower, further preferably 70 ° C. or higher and 120 ° C. or lower, and particularly preferably 80 ° C. or higher and 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, an organic halide is generally used as an initiator, and a transition metal complex is used as a catalyst to carry out a polymerization reaction. The organic halide used as the initiator may be monofunctional or bifunctional or higher. It is preferable to use a bifunctional compound in that a block copolymer having an a- (ba) n-type structure can be easily obtained efficiently. Moreover, bromide and chloride are preferable as the type of halogen. The reaction temperature in the ATRP method is preferably 20 ° C. or higher and 200 ° C. or lower, and more preferably 50 ° C. or higher and 150 ° C. or lower. When the reaction temperature is 20 ° C. or higher, the polymerization reaction can proceed smoothly.

By the living radical polymerization method, a- (ba) n such as (aba) triblock copolymer composed of polymer block (a)-(meth) acrylic polymer block (b) -polymer block (a). When obtaining a mold structure, for example, the target block copolymer may be obtained by sequentially polymerizing each block. In this case, first, as the first polymerization step, the polymer block (a) is obtained by using the constituent monomers of the polymer block (a). Next, as a second polymerization step, the (meth) acrylic polymer block (b) is obtained by using the constituent monomers of the (meth) acrylic polymer block (b). Further, as a third polymerization step, the (aba) triblock copolymer can be obtained by polymerizing 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 above-mentioned second polymerization step and third polymerization step, a higher-order block copolymer such as a pentablock copolymer can be obtained.

Further, when it is produced by a method including the following two-step polymerization step, it is preferable because the target product can be obtained more efficiently. That is, as the first polymerization step, the constituent monomer of the (meth) acrylic polymer block (b) is used to obtain the (meth) acrylic polymer block (b), and then the second polymerization step is heavy. The constituent monomers of the coalesced block (a) are polymerized to obtain a polymer block (a). As a result, a (aba) triblock copolymer composed 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 the case where each block is sequentially polymerized and produced. Further, by repeating the above-mentioned first polymerization step and second polymerization step, a higher-order block copolymer such as a tetrablock copolymer can be obtained.

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. Known chain transfer agents can be used, and 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-undecane thiol, 1-dodecane thiol, 2-dodecane thiol, 1-tridecane thiol, 1-tetradecane thiol, 3-methyl-3-undecane thiol, 5-ethyl-5-decane thiol, tert-tetradecane thiol, 1 -In addition to alkylthiol compounds having an alkyl group having 2 to 20 carbon atoms such as hexadecanethiol, 1-heptadecanethiol and 1-octadecanethiol, mercaptoacetic acid, mercaptopropionic acid, 2-mercaptoethanol and the like can be mentioned. One or more of the above can be used.

In the production of the block copolymer used in the present disclosure, a known polymerization solvent can be used in living radical polymerization. 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 and dimethylsulfoxide, Examples include alcohol and water. In addition, bulk polymerization or the like may be carried out without using a polymerization solvent.

5-3. Preferred Aspects of the Adhesive Layer When the thin film layer of the pressure-sensitive adhesive sheet is the thin film layer 1, the pressure-sensitive adhesive composition preferably contains an acrylic adhesive polymer (B) and is a vinyl polymer (A). It is more preferable that the acrylic adhesive polymer (B) is contained. When the thin film layer of the pressure-sensitive adhesive sheet is the thin film layer 2, the pressure-sensitive adhesive composition may contain the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B). When the present pressure-sensitive adhesive composition contains a vinyl polymer (A) and an acrylic adhesive polymer (B), the vinyl polymer (A) has an appropriate compatibility with the acrylic adhesive polymer (B). It is preferable to have. In this case, the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition containing the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B) exhibits good transparency and the vinyl polymer (A) in the pressure-sensitive adhesive layer. ) May be partially segregated, and the concentration of the vinyl polymer (A) on the surface layer may be higher than that of the other parts.

In this way, when the concentration of the vinyl polymer (A) on the surface layer of the pressure-sensitive adhesive layer is higher than the others, the pressure-sensitive adhesive layer near the adhesive interface has a relatively high Tg, which is good even under high temperature conditions. Can exhibit excellent adhesiveness. Further, since the adhesive layer as a whole has a low Tg and is sufficiently flexible, when applied to a decorative film, for example, even when the film base material undergoes thermal expansion and contraction, it follows this and stress is suitable. Can be relaxed. As a result, when the present decorative film is adhered to the adherend by vacuum compressed air molding, the effect of suppressing the generation of shock lines of the decorative film can be enhanced. In addition to such segregation behavior of the vinyl polymer (A) in the present pressure-sensitive adhesive composition, the difference in Tg between the surface layer of the pressure-sensitive adhesive layer and the entire pressure-sensitive adhesive layer, which will be described later, is the difference in Tg with respect to the acrylic pressure-sensitive adhesive polymer (B). It can be adjusted by appropriately setting the compounding ratio of A), the monomer composition (polarity) and molecular weight of the vinyl polymer (A), Tg, Mw / Mn and the like.

When the pressure-sensitive adhesive composition contains the vinyl polymer (A), the pressure-sensitive adhesive composition contains the vinyl polymer (A) in terms of solid content with respect to 100 parts by mass of the acrylic pressure-sensitive adhesive polymer (B). It is preferably contained in an amount of 0.5 parts by mass or more and 60 parts by mass or less. The lower limit of the content is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and further preferably 4 parts by mass or more. The upper limit of the preferable content is 50 parts by mass or less, more preferably 40 parts by mass or less, and further preferably 30 parts by mass or less. The preferred content range is 1 part by mass or more and 40 parts by mass or less, and more preferably 3 parts by mass or more and 30 parts by mass or less. When the amount of the vinyl polymer (A) used is less than 0.5 parts by mass, the segregation of the vinyl polymer (A) in the pressure-sensitive adhesive layer is insufficient, and a satisfactory result cannot be obtained particularly in the high temperature adhesiveness. There is. On the other hand, if it exceeds 60 parts by mass, the vinyl polymer (A) may be excessively segregated, resulting in insufficient step followability and adhesiveness including tack. In addition, the adhesive layer may be phase-separated from the acrylic adhesive polymer (B) to reduce the transparency of the adhesive layer.

[Tg (first Tg) of the entire pressure-sensitive adhesive layer formed from the present pressure-sensitive adhesive composition]
The glass transition temperature (Tg) of the entire pressure-sensitive adhesive layer (hereinafter, also referred to as “the present pressure-sensitive adhesive layer”) formed from the present pressure-sensitive adhesive composition, that is, the first Tg is −80 ° C. or higher and 20 ° C. or lower. Can be a range. 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 the first Tg may be 15 ° C. or lower, 10 ° C. or lower, 0 ° C. or lower, −10 ° C. or lower, −20 ° C. or lower. It may be as follows. Further, the range of the first Tg can be appropriately combined with these upper and lower limits, but is, for example, a range of −70 ° C. or higher and 30 ° C. or lower, and for example, −60 ° C. or higher and 20 ° C. or lower. For example, it is −50 ° C. or higher and −10 ° C. or lower. When the first Tg is less than −80 ° C., the cohesive force of the obtained pressure-sensitive adhesive layer becomes insufficient, and the curved surface adhesiveness and the like tend to deteriorate. When the first Tg exceeds 20 ° C., the step followability and the adhesive strength under low temperature conditions may not be sufficient. The Tg of the entire pressure-sensitive adhesive layer can be obtained by DSC at a heating rate of 10 ° C./min and a nitrogen atmosphere as the measurement atmosphere.

[Tg (second Tg) calculated from the composition of the surface layer portion of the adhesive layer]
When the thin film layer of the pressure-sensitive adhesive sheet is the thin film layer 2, when the second Tg, that is, the pressure-sensitive adhesive composition is applied to the separator and then dried or irradiated with active energy rays to obtain the pressure-sensitive adhesive layer, The Tg calculated from the composition of the surface layer portion of the pressure-sensitive adhesive layer obtained by X-ray photoelectron spectroscopic analysis is 70 ° C. or higher. Specifically, the second Tg is obtained by calculation from the composition ratio of the vinyl polymer (A) and the acrylic adhesive polymer (B) obtained by X-ray photoelectron spectroscopy (XPS), and is a pressure-sensitive adhesive. It can be regarded as Tg of the composition forming the surface layer from the surface of the layer to the depth of about 20 nm. That is, in XPS, photoelectrons generated by irradiating the surface of the pressure-sensitive adhesive layer with X-rays can be detected, and composition information can be obtained from the kinetic energy, and the detection depth is generally several nm. Therefore, composition information regarding the surface layer portion of about several nm can be obtained from the surface of the pressure-sensitive adhesive layer by XPS, and this can be regarded as Tg of the thin film layer 2. The details of the measurement method can follow the operations described in Examples described later.

When the thin film layer of the present adhesive sheet is the thin film layer 2, since the second Tg is 70 ° C. or higher, the adhesiveness is not exhibited at room temperature, and the handleability can be improved at the time of preforming. In addition, it is possible to suppress the occurrence of shock lines when applied to vacuum compressed air forming. Further, when the second Tg is 70 ° C. or higher, it becomes easy to sufficiently increase the difference between the first Tg and the second Tg, and as a result, the adhesiveness to the curved surface and the high temperature adhesiveness of the adherend Durability can be ensured. The second Tg is more preferably 75 ° C. or higher, further preferably 80 ° C. or higher, and even more preferably 85 ° C. or higher. The second Tg can be appropriately adjusted depending on the Tg of the vinyl polymer (A), the compounding ratio, and the like. The upper limit of the second Tg is not particularly limited, but is, for example, 180 ° C. or lower.

When the thin film layer of the present adhesive sheet is the thin film layer 1, the second Tg is not particularly limited, but is preferably 0 ° C. or higher. The second Tg is more preferably 10 ° C. or higher, further preferably 30 ° C. or higher, still more preferably 40 ° C. or higher, still more preferably 50 ° C. or higher, and even more preferably 60 ° C. or higher. is there.

[Difference between Tg (first Tg) of the entire pressure-sensitive adhesive layer and Tg (second Tg) calculated from the composition of the surface layer portion of the pressure-sensitive adhesive layer]
In the present pressure-sensitive adhesive composition, the second Tg (Tg calculated from the composition of the surface layer portion of the pressure-sensitive adhesive layer) is higher than the first Tg (Tg of the entire pressure-sensitive adhesive layer) by 30 ° C. or more. Is preferable. According to the pressure-sensitive adhesive layer having such a Tg composition, the adhesiveness decreases as the temperature of the pressure-sensitive adhesive layer obtained by a conventional general pressure-sensitive adhesive increases, whereas the adhesiveness decreases at a high temperature (peeling to an adherend). It can exhibit (strength) and high curved surface adhesiveness. Further, when the second Tg is higher than the first Tg by 30 ° C. or more, the decorative film provided with the pressure-sensitive adhesive layer formed from the present pressure-sensitive adhesive composition is complicated such as curved surfaces and uneven portions. It follows the shape and shows good adhesiveness. Further, for example, even when the film base material shrinks under high temperature conditions, it suppresses appearance defects such as slippage, peeling, and floating, and exhibits excellent durability.

The second Tg is preferably 40 ° C. or higher, more preferably 50 ° C. or higher, further preferably 60 ° C. or higher, still more preferably 65 ° C. or higher, and 70 ° C. or higher 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 limited to 280 ° C. from the values that the first Tg and the second Tg can take, and is generally 200 ° C. It is as follows.

[Mass fraction (A / A + B) of the vinyl polymer (A) to the total mass of the vinyl polymer (A) and the acrylic adhesive polymer (B) on the surface layer portion of the pressure-sensitive adhesive layer]
In the measurement of the second Tg, the composition analysis by X-ray photoelectron spectroscopy of the surface layer of the pressure-sensitive adhesive layer is performed, and at that time, the mass fraction of the vinyl polymer (A) in the surface layer can be obtained. This mass fraction can be used as an index of the segregated state of the vinyl polymer (A) in the surface layer portion of the pressure-sensitive adhesive layer.

For example, the mass fraction of the vinyl polymer (A) in the surface layer portion of the pressure-sensitive adhesive layer is preferably 55% or more and 95% or less. Within this range, segregation of the vinyl polymer (A) to the surface layer portion occurs, and curved surface adhesiveness and durability can be obtained even under high temperature and high humidity. The mass fraction of the vinyl polymer (A) is more preferably 60% or more, further preferably 65% or more, still more preferably 70% or more, still more preferably 75% or more, still more. It is preferably 80% or more. The mass fraction is preferably 95% or less, more preferably 90% or less.

[Transparency (haze value)]
The haze value can be used as an index for evaluating the transparency of the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition. The pressure-sensitive adhesive layer obtained from the present pressure-sensitive adhesive composition exhibits good transparency. Further, in the embodiment in which the pressure-sensitive adhesive composition contains the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B), the vinyl polymer (A) has an appropriate compatibility with the acrylic pressure-sensitive polymer (B). When present, the pressure-sensitive adhesive layer containing these exhibits good transparency.

The haze value can be evaluated by, for example, the following method. That is, one separator attached to the adhesive sheet is peeled off, the adhesive sheet is transferred to a glass plate, the other separator is peeled off, and then allowed to stand for one day under the conditions of 23 ° C. and 50% RH to haze. Measure the haze value using a meter. It can be evaluated that the lower the haze value, the better the transparency. The preferred haze value is 2.0 or less. When the haze value is 2.0 or less, it can be said that there is a certain preferable transparency. A more preferable haze value is 1.6 or less, more preferably 1.4 or less, and even more preferably 1.0 or less.

5-4. Other Ingredients In addition to the vinyl polymer (A) and the acrylic adhesive polymer (B), preferred embodiments of the present pressure-sensitive adhesive composition include a cross-linking agent, a pressure-imparting agent, a plasticizer, and an antioxidant, if necessary. The composition may also contain additives such as an ultraviolet absorber, an antiaging agent, a flame retardant, a fungicide, a silane coupling agent, a filler, and a colorant.

[Crosslinking agent]
The pressure-sensitive adhesive composition may contain a cross-linking agent. Although the cross-linking agent is not always necessary, its addition is considered depending on the intended adhesive properties and the form of the pressure-sensitive adhesive composition, for example, whether it is in the form of an emulsion or a solution. By containing a cross-linking agent, the cohesive force and adhesive force of the pressure-sensitive adhesive layer obtained from the present pressure-sensitive adhesive composition can be adjusted, and further, adhesiveness under high temperature and high humidity and adhesiveness to curved surfaces can be imparted. be able to. Examples of the cross-linking 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 so on. Of 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-aziridylurea, 1,1'. -(Hexamethylene) bis-3,3-aziridylurea, ethylenebis- (2-aziridinyl propionate), tris (1-aziridinyl) phosphine oxide, 2,4,6-triaziridinyl-1,3,5 -Triazine, trimethylolpropane-tris- (2-aziridinyl propionate) and the like can be mentioned.

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, diglycidyl aniline, tetraglycidyl xylenediamine, N, N, N', N'-tetraglycidyl-m-xylylene diamine, 1,3-bis (N, N-) Examples thereof include polyfunctional glycidyl compounds such as diglycidyl aminomethyl) cyclohexane, trimethylolpropane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, and sorbitol polyglycidyl ether.

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

Examples of the aromatic isocyanate include diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene diisocyanate (NDI), p-phenylenedi isocyanate (PPDI), xylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI). , Trizine diisocyanate (TODI) and the like. Examples of the aliphatic isocyanate include hexamethylene diisocyanate (HDI), ricin diisocyanate (LDI), and ricin triisocyanate (LTI). Examples of the alicyclic isocyanate include isophorone diisocyanate (IPDI), cyclohexyl diisocyanate (CHDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI) and the like. Examples of the modified isocyanate include urethane-modified, dimeric, trimer, carbodiimide-modified, allophanate-modified, burette-modified, urea-modified, isocyanurate-modified, oxazolidone-modified, and isocyanate of the above-mentioned isocyanate compounds. Examples include base-terminal prepolymers.

The content of the cross-linking agent can be preferably 0.01 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the acrylic adhesive polymer (B). A more preferable lower limit is 0.03 parts by mass or more, and even more preferably 0.05 parts by mass or more. Further, the more preferable upper limit is 5 parts by mass or less, and more preferably 2 parts by mass or less. The more preferable range is 0.03 parts by mass or more and 5 parts by mass or less, and the more preferable range is 0.05 parts by mass or more and 2 parts by mass or less.

[Adhesive imparting agent]
As the tackifier, rosin derivatives such as rosin ester, gum rosin, tall oil rosin, hydrogenated rosin ester, maleated rosin, and disproportionate rosin ester; mainly terpene phenol resin, α-pinene, β-pinene, limonene, etc. Examples thereof include terpene-based resins; (hydrogenated) petroleum resins; kumaron-indene-based resins; hydrogenated aromatic copolymers; styrene-based resins; phenol-based resins; xylene-based resins; (meth) acrylic-based polymers.

[Plasticizer]
Examples of the plasticizer include phthalates such as din-butylphthalate, din-octylphthalate, bis (2-ethylhexyl) phthalate, din-decylphthalate, and diisodecylphthalate; bis (2-ethylhexyl) adipate and din. -Adipic acid esters such as octyl adipate; sebacic acid esters such as bis (2-ethylhexyl) sebacate and din-butyl sebacate; azeline acid esters such as bis (2-ethylhexyl) azelate; paraffins such as chlorinated paraffin Glycols such as polypropylene glycol; Epoxy-modified vegetable oils such as epoxidized soybean oil and epoxidized linseed oil; Phthalate esters such as trioctyl phosphate and triphenyl phosphate; Subphosphate esters such as triphenyl phosphite; Ester oligomers such as esters of adipic acid and 1,3-butylene glycol; low molecular weight polymers such as low molecular weight polybutene, low molecular weight polyisobutylene, low molecular weight polyisoprene; oils such as process oils and naphthenic oils Can be mentioned.

〔Antioxidant〕
Antioxidants include 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisol, 2,6-di-tert-butyl-4-ethylphenol, stearyl-β- (3,5-di). -Tert-Butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 4, 4'-thiobis (3-methyl-6-tert-butylphenol), 4,4'-butylidenebis (3-methyl-6-tert-butylphenol), 3,9-bis [1,1-dimethyl-2- [β] -(3-tert-Butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] 2,4,8,10-tetraoxaspiro [5.5] undecane, 1,3-tris (2-methyl- 4-Hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene -3- (3', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate] methane, bis [3,3'-bis- (4'-hydroxy-3'-tert-butylphenyl) buty Rick acid] glycol ester, 1,3,5-tris (3', 5'-di-tert-butyl-4'-hydroxybenzyl) -S-triazine-2,4,6- (1H, 3H, 5H) Phenolic antioxidants such as trion and tocopherols; sulfur-based antioxidants such as dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, stearyl 3,3'-thiodipropionate Agents: Triphenylphosphite, diphenylisodecylphosphite, 4,4'-butylidene-bis (3-methyl-6-tert-butylphenylditridecyl) phosphite, cyclic neopentanetetraylbis (octadecylphosphite) , Tris (nonylphenyl) phosphite, tris (monononylphenyl) phosphite, tris (dinonylphenyl) phosphite, diisodecylpentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene- 10-Oxide, 10- (3,5-di-tert-butyl-4-hydroxybenzyl) -9,10- Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene, tris (2,4-di-tert-butylphenyl) phos Fight, cyclic neopentantetrayl bis (2,4-di-tert-butylphenyl) phosphite, cyclic neopentantetraylbis (2,6-di-tert-butyl-4-methylphenyl) phosphite, Examples thereof include phosphorus-based antioxidants such as 2,2-methylenebis (4,6-di-tert-butylphenyl) octylphosphite.

[UV absorber]
Examples of the ultraviolet absorber include salicylic acid-based ultraviolet absorbers such as phenyl salicylate, p-tert-butylphenyl salicylate, and p-octylphenyl salicylate; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 2-hydroxy-. 4-Octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy Benzopenone-based ultraviolet absorbers such as -5-sulfobenzophenone and bis (2-methoxy-4-hydroxy-5-benzoylphenyl) methane; 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2-( 2'-Hydroxy-5'-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-Tert-Butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2) '-Hydroxy-3', 5'-di-tert-amylphenyl) benzotriazole, 2- (2'-hydroxy-4'-octoxyphenyl) benzotriazole, 2- [2'-hydroxy-3'-( 3 ", 4", 5 ", 6" -tetrahydrophthalimidemethyl) -5'-methylphenyl] benzotriazole, 2,2-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazole-2-yl) phenol], 2- (2'-hydroxy-5'-methacryloxyphenyl) -2H-benzotriazole, 2,2'-methylenebis [4- (1,1,3,3) 3-Tetramethylbutyl) -6- (2H-benzotriazole-2-yl) phenol] and other benzotriazole-based ultraviolet absorbers; 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate, ethyl-2- Cyanacrylate-based UV absorbers such as cyano-3,3'-diphenylacrylate; nickel bis (octylphenyl) sulfate, [2,2'-thiobis (4-tert-octylphenolate)]-n-butylamine nickel, nickel Complex-3,5-diet Examples thereof include nickel-based ultraviolet stabilizers such as ert-butyl-4-hydroxybenzyl-phosphate monoethylate and nickel-dibutyldithiocarbamate.

[Anti-aging agent]
Anti-aging agents include poly (2,2,4-trimethyl-1,2-dihydroquinoline), 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinolin, 1- (N-phenylamino). ) -Naphthalene, tert-butyldiphenylamine, dialkyldiphenylamine, N, N'-diphenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N, N'-di-2-naphthyl-p- Phenylene diamine, 2,6-di-tert-butyl-4-methylphenol, mono (α-methylbenzyl) phenol, di (α-methylbenzyl) phenol, tri (α-methylbenzyl) phenol, 2,2'- Methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis (6-tert-butyl-3-methylphenol), 4,4'-thiobis (6-tert-butyl-3-methylphenol), 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,5-di-tert-butylhydroquinone, 2,5-di-tert -Amilhydroquinone, 2-mercaptobenzimidazole, zinc salt of 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, nickel dibutyldithiocarbamate, tris (nonylphenyl) phosphite, dilauryl thiodipropionate, dithiodipropionate Examples include stearyl and the like.

〔Flame retardants〕
Flame retardants include tetrabromobisphenol A, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, hexabromobenzene, tris (2,3-dibromopropyl) isocyanurate, 2,2-bis. (4-Hydroxyethoxy-3,5-dibromophenyl) Halogen-based flame retardants such as propane, decabromodiphenyl oxide, and halogen-containing polyphosphate; ammonium phosphate, tricresyl phosphate, triethyl phosphate, tris (β-chloroethyl) Phenyl retardants such as phosphate, trischloroethyl phosphate, trisdichloropropyl phosphate, cresildiphenyl phosphate, xylenyldiphenyl phosphate, acidic phosphoric acid ester, nitrogen-containing phosphorus compound; red phosphorus, tin oxide, antimony trioxide, water Inorganic flame retardants such as zirconium oxide, barium metaborate, aluminum hydroxide, magnesium hydroxide; poly (dimethoxysiloxane), poly (diethoxysiloxane), poly (diphenoxysiloxane), poly (methoxyphenoxysiloxane), methylsilicate , Ethyl silicate, phenyl silicate and other siloxane flame retardants.

[Antifungal agent]
Examples of the fungicide include benzimidazole, benzothiazole, trihaloallyl, triazole, and organic nitrogen sulfur compounds.
〔Silane coupling agent〕
Examples of the silane coupling agent include vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxy. Propyltriethoxysilane, β- (3,4-epylcyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (Aminoethyl) -γ-aminopropyltrimethoxysilane and the like can be mentioned.
〔filler〕
Examples of the filler include inorganic powder fillers such as calcium carbonate, titanium oxide, mica, and talc; and fibrous fillers such as glass fiber and organic reinforcing fiber.

5-5. Form of the present pressure-sensitive adhesive composition There are no particular restrictions on the form of the present pressure-sensitive adhesive composition. For example, it may be used as a form of a solvent-type pressure-sensitive adhesive composition dissolved in an organic solvent such as ethyl acetate, or a form of an emulsion-type pressure-sensitive adhesive composition in which an acrylic pressure-sensitive adhesive polymer and a tackifier are dispersed in an aqueous medium. May be used as. In the case of the solution type pressure-sensitive adhesive composition and the emulsion type pressure-sensitive adhesive composition, the medium such as the organic solvent or water used is usually 20 to 95 parts by mass out of 100 parts by mass of the total amount of the pressure-sensitive adhesive composition.

When used as an emulsion type pressure-sensitive adhesive, a stabilizer may be blended. Examples of this stabilizer include cadmium stearate, zinc stearate, barium stearate, calcium stearate, lead dibutyltin dilaurate, tris (nonylphenyl) phosphite, triphenylphosphite, diphenylisodecylphosphite and other vinyl chlorides. Stabilizers; di-n-octylstinbis (isooctylthioglycolic acid ester) salt, di-n-octylstinmalate polymer, di-n-octylstindilaurate, di-n-octylstinmaleic acid Ester salt, di-n-butyltin bismaleic acid ester salt, di-n-butyltin maleate polymer, di-n-butyltin bisoctylthioglycol ester salt, di-n-butyltin β-mercaptopropionate polymer, di -N-butyltin dilaurate, di-n-methylstinbis (isooctyl mercaptoacetate) salt, poly (thiobis-n-butyltin sulfate), monooctyltintris (isooctylthioglycolic acid ester), dibutyltin maleate, di-n- Organic tin stabilizers such as butyl tinumarate ester carboxylate and di-n-butyl summalate ester mercaptide; tribasic lead sulfate, dibasic lead phosphite, basic lead sulfite, dibasic phthal. Lead-based stabilizers such as lead acid, lead silicate, basic lead stearate, lead stearate; metals such as cadmium-based soap, zinc-based soap, barium-based soap, lead-based soap, composite metal soap, calcium stearate, etc. Examples include soap-based stabilizers.

In addition to the vinyl polymer (A) and the acrylic adhesive polymer (B), the present pressure-sensitive adhesive composition includes monofunctional and / or polyfunctional (meth) acrylic acid-based monomers, and By preparing the composition containing a photopolymerization initiator or the like, it may be used as a form of a so-called syrup-type photocurable pressure-sensitive adhesive composition that is cured by active energy rays such as ultraviolet rays.

In the case of a photocurable pressure-sensitive adhesive composition, an organic solvent or the like may be contained in the composition, but it is generally used as a solvent-free type that does not contain solvents.

Examples of the monofunctional (meth) acrylic acid-based monomer include (meth) acrylic acid alkyl esters having an alkyl group having 1 to 12 carbon atoms; cyclohexyl (meth) acrylic acid, dicyclopentyl (meth) acrylic acid, and (meth). ) (Meta) acrylic acid esters having a cyclic structure such as isobornyl acrylate; (meth) hydroxyethyl acrylate, (meth) hydroxypropyl acrylate, (meth) hydroxyalkyl acrylate, etc. Esters; (meth) acrylic acid and the like can be mentioned. These compounds may be used alone or in combination of two or more.

Examples of the polyfunctional (meth) acrylic acid-based monomer include di (meth) acrylates of alkylene glycols such as butanediol di (meth) acrylate and hexanediol di (meth) acrylate; di (meth) acrylate of triethylene glycol. Di (meth) acrylates of polyalkylene glycols such as trimethylolpropantri (meth) acrylate and its ethylene oxide and / or propylene oxide modified product, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and the like. Can be mentioned. In addition to this, a polymer (macromonomer) having a (meth) acryloyl group such as polyurethane (meth) acrylate and polyisoprene-based (meth) acrylate can also be used. Specific examples of the polyisoprene-based (meth) acrylate compound include an esterified product of a maleic anhydride adduct of an isoprene polymer and 2-hydroxyethyl methacrylate. These compounds may be used alone or in combination of two or more.

Examples of the photopolymerization initiator include benzoin and its alkyl ethers, acetophenones, anthraquinones, thioxanthones, ketals, benzophenones, xanthones, acylphosphine oxides, α-diketones and the like. In addition, a photosensitizer can also be used in combination to improve the sensitivity of the active energy rays. Examples of the photosensitizer include benzoic acid-based and amine-based photosensitizers. These can also be used in combination of two or more kinds. The amount of the photoinitiator and the photosensitizer used is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the monofunctional and / or polyfunctional (meth) acrylic acid-based monomer.

Further, in addition to the photocurable pressure-sensitive adhesive composition described above, the present pressure-sensitive adhesive composition includes the above-mentioned vinyl polymer (A), monofunctional and / or polyfunctional (meth) acrylic acid-based monomers. It can also be used as a photocurable adhesive composition with a composition containing a photopolymerization initiator. The acrylic adhesive polymer (B) can be mixed with the photocurable adhesive composition, if necessary.

Hereinafter, specific examples embodying the disclosure of this specification will be shown. However, the disclosure of the present specification is not limited to the following specific examples. In the following description, "part" means parts by mass, and "%" means% by mass.

Various analyzes in the present specification were carried out by the methods described below.
<Solid content>
Approximately 1 g of the measurement sample was weighed (a), and then the residue after drying in a ventilation dryer at 155 ° C. for 30 minutes (b) was measured (b) and calculated from the following formula. A weighing bottle was used for the measurement. Other operations were in accordance with JIS K 0067-1992 (Chemical product weight loss and residue test method).
Solid content (%) = (b / a) x 100

<Molecular weight measurement>
The molecular weight was measured by GPC under the following conditions.
GPC: Tosoh (HLC-8120)
Column: Tosoh (TSKgel-Super MP-M x 4)
Sample concentration: 0.1%
Flow rate: 0.6 ml / min Eluent: Tetrahydrofuran Column temperature: 40 ° C
Detector: Differential Refractometer (RI)
Standard substance: polystyrene

<Glass transition temperature (Tg) and melting point>
The Tg and melting point of the entire pressure-sensitive adhesive layer formed from the polyolefin resin, the vinyl polymer (A), the acrylic pressure-sensitive adhesive polymer (B), and the pressure-sensitive adhesive composition are in accordance with JIS K7121 under the following conditions under DSC. Measured in.
DSC: Made by TA Instrument (Q-100)
Temperature rise temperature: 10 ° C / min Measurement atmosphere: Nitrogen <softening point>
The softening points of the polyolefin-based resin and the polyester-based resin were measured by the ring-and-ball method in accordance with JIS K6863. When the thin film layer was a rosin ester resin, the measurement was carried out by the ring and sphere method in accordance with JIS5902.

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

1. 1. Synthesis of vinyl polymer (A) [Synthesis example 1: Synthesis of polymer A-1]
Butyl acetate (200 parts by mass) and dimethyl-2,2'-azobis (2-methylpropionate) (manufactured by Wako Pure Chemical Industries, Ltd., trade name "V-" in a four-necked flask with an internal volume of 1 liter. A mixed solution consisting of 601 ”) (0.9 parts by mass) was charged, and the mixed solution was sufficiently degassed by bubbling nitrogen gas to raise the internal temperature of the mixed solution to 90 ° C. Separately, methyl methacrylate (hereinafter referred to as "MMA") (165 parts by mass), isobornyl methacrylate (hereinafter referred to as "IBXMA") (44 parts by mass), V-601 (17 parts by mass), butyl acetate (90 parts by mass). Polymerization was carried out by dropping the mixed solution consisting of (part) into the flask from the dropping funnel over 5 hours. After completion of the dropping, the polymerization solution is added dropwise to a mixed solution consisting of methanol (4800 parts by mass) and distilled water (1200 parts by mass) to isolate the vinyl polymer in the polymerization solution and obtain the polymer A-1. It was. The polymer composition of the obtained polymer A-1 was 80% by mass of MMA and 20% by mass of IBXMA as a result of calculation from the charged amount and the monomer consumption by GC measurement. The Mw of the polymer A-1 was 6,700, the Mn was 4,370, the Mw / Mn was 1.53, and the Tg was 108 ° C.

2. 2. Synthesis of Acrylic Adhesive Polymer (B) [Synthesis Example 2: Synthesis of Polymer B-1]
In a four-necked flask with an internal volume of 3 liters, methoxyethyl acrylate (hereinafter referred to as "MEA") (413 parts by mass), 2-hydroxyethyl acrylate (hereinafter referred to as "HEA") (27 parts by mass), acrylic N-Butyl acid (hereinafter referred to as "BA") (90 parts by mass) and ethyl acetate (980 parts by mass) were charged, and the mixed solution was sufficiently degassed by bubbling nitrogen gas to raise the internal temperature of the mixed solution to 75. The temperature rises to ℃, and 2,2'-azobis (2,4-dimethylvaleronitrile) (manufactured by Wako Pure Chemical Industries, Ltd., trade name "V-65") (0.25 parts by mass) is charged for 5 hours. It was polymerized. Ethyl acetate was added to a solid content concentration of 30% to obtain an ethyl acetate solution of polymer B-1. The polymer composition of the obtained polymer B-1 was 78% by mass of MEA, 5% by mass of HEA, and 17 parts by mass of BA. The Mw of the polymer B-1 was 572,000, the Mn was 160,000, the Mw / Mn was 3.58, and the Tg was −35 ° C.

[Synthesis Example 3: Synthesis of Polymer B-2]
Acrylic acid (hereinafter referred to as "AA") (30 parts by mass), BA (210 parts by mass), methyl acrylate (hereinafter referred to as "MA") (360 parts by mass) in a four-necked flask having an internal volume of 3 liters. , Ethyl acetate (1000 parts by mass) was charged, the mixed solution was sufficiently degassed by bubbling nitrogen gas, the internal temperature of the mixed solution was raised to 75 ° C., and V-65 (0.30 parts by mass) was charged. It was polymerized for 5 hours. Ethyl acetate was added to a solid content concentration of 30% to obtain an ethyl acetate solution of polymer B-2. The polymer composition of the obtained polymer B-2 was 5% by mass of AA, 35% by mass of BA, and 60 parts by mass of MA. The Mw of the polymer B-2 was 529,000, the Mn was 142,000, the Mw / Mn was 3.73, and the Tg was 6 ° C.

[Synthesis Example 4: Synthesis of Polymer B-3]
In a four-necked flask with an internal volume of 1 L, dibenzyltrithiocarbonate (3.18 parts by mass) as a RAFT agent, styrene (75 parts by mass, hereinafter referred to as "St") as a monomer, and N-phenylmaleimide (hereinafter referred to as "St"). 125 parts by mass (hereinafter referred to as "PhMI") and acetonitrile (466 parts by mass) were charged as a solvent, and the mixture was sufficiently degassed by nitrogen bubbling to raise the internal temperature of the mixed solution to 70 ° C. Then, 2,2'-azobis (2-methylbutyronitrile) (0.51 part by mass, hereinafter referred to as "ABN-E") was charged as a polymerization initiator, and the polymerization was started. After 3 hours, the reaction was stopped by cooling to room temperature. The above polymerization solution was reprecipitated and purified from methanol and vacuum dried to obtain a polymer block (a). The obtained polymer block (a) was Mn10,900. Tg was 206 ° C.
The obtained polymer block (a) (21.1 parts by mass), MEA (234 parts by mass), BA (51 parts by mass), and HEA (15 parts by mass) as monomers were placed in a four-necked flask having an internal volume of 1 L. Acetonitrile (107 parts by mass) was charged as a solvent, and the mixture was sufficiently degassed by nitrogen bubbling to raise the internal temperature of the mixed solution to 70 ° C. Next, ABN-E (0.08 parts by mass) was charged as a polymerization initiator, and polymerization was 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 a pressure-sensitive adhesive solution. The obtained (a)-(b)-(a) block copolymer (referred to as "polymer B-3") has PhMI 3% by mass, St2% by mass, MEA74% by mass, BA16% by mass, and HEA5. It consisted of% by mass, Mw was 358,000, Mn was 16,0000, Mw / Mn was 2.24, and Tg was −35 ° C. The composition and analysis results of polymer B-3 are shown in Table 1.

3. 3. Manufacture and evaluation of adhesive sheets
Example 1
(1) Coating of Thin Film Layer 1 Acid-modified polyolefin resin C-1 (Toyo Tuck PMA-T manufactured by Toyobo Co., Ltd.) was dissolved in toluene to prepare a solution having a solid content concentration of 5% by mass. This solution was applied onto a 50 μm-thick polyethylene terephthalate (hereinafter referred to as “PET”) separator using a doctor blade so that the dried thickness would be several μm. The coating film was dried at 80 ° C. for 1 minute.

(2) Preparation and coating of pressure-sensitive adhesive composition Takenate D-110N (Mitsui Kagaku Co., Ltd.) as a cross-linking agent in the solution (solid content concentration 30%) containing the polymer B-1 obtained in Synthesis Example 2 above. An isocyanate-based cross-linking agent (solid content concentration: 75% by mass) (0.16 parts by mass) was mixed to obtain a pressure-sensitive adhesive composition 1.

(3) Production of Adhesive Sheet On the PET separator with a thin film produced in (1) above, the adhesive composition 1 was applied using a doctor blade so that the thickness of the adhesive layer after drying was 50 μm. .. The coating film was dried at 80 ° C. for 4 minutes. Then, a PET separator having a thickness of 38 μm, which has a different peeling force from the separator, was attached and allowed to stand at 40 ° C. for 5 days for aging (aging) to obtain an adhesive sheet with a double-sided separator. In Examples 10 and 11 and Comparative Examples 5 and 6, the pressure-sensitive adhesive composition was directly applied onto a PET separator having a thickness of 50 μm.

(4) Various Measurements and Evaluations of Adhesive Sheets The adhesive sheets obtained in (3) above were subjected to various measurements and evaluations by the following methods. The measurement of "Tg of the surface layer portion of the adhesive layer" was carried out in Examples 9 to 11 and Comparative Example 4. The results obtained are shown in Tables 2 and 3.

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

<Transparency (haze value)>
The release film was peeled off from the adhesive sheet, transferred to a glass plate (1 mm thick), and the other release film was peeled off. After allowing to stand for one day under the conditions of 23 ° C. and 50% RH, the haze value (%) is measured using the haze meter "Haze Meter NDH2000" (model name) manufactured by Nippon Denshoku Co., Ltd. The transparency in the composition was evaluated.

<Tg on the surface layer of the adhesive layer>
From the peak area ratio of O1s and C1s measured by the X-ray photoelectron spectrometer (XPS) of the pressure-sensitive adhesive sheet, it can be grasped as Tg of the composition forming the surface layer portion of the pressure-sensitive adhesive layer. To the total amount of the vinyl polymer in the surface portion of the pressure-sensitive adhesive layer (A) and the acrylic adhesive polymer (B), the vinyl polymer (A) and the mass fraction of the acrylic adhesive polymer (B) (w _A and w _B ) was calculated, and the Tg of the surface layer portion was calculated based on the FOX formula.
The XPS measurement was performed under the following conditions.
Equipment: ULVAC-PHI PHI5000 VersaProbe
X-ray: Al-Kα (1486.6 eV)
X-ray incident angle on the sample: 0 ° (angle of the sample measurement surface with respect to the normal)
Photoelectron detection angle: 45 ° (angle of sample measurement surface with respect to normal)

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 measured by XPS is composed of a vinyl polymer (A) and an acrylic adhesive polymer (B) as shown in the following formula (1). It is represented by the ratio of the number of oxygen atoms present to the number of carbon atoms per unit weight of the surface layer portion of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition.

here,
(O / C) A + B : The ratio of the pressure-sensitive adhesive composition the number of oxygen atoms calculated from O1s and C1s peak area ratio obtained from the XPS measurement of the pressure-sensitive adhesive layer obtained by drying the carbon atoms W _A: Weight fraction of vinyl polymer (A) to total amount of vinyl polymer (A) and acrylic adhesive polymer (B) M _wA : Weighted average molecular weight of all constituent monomer units of vinyl polymer (A) M _w-B: acrylic pressure-sensitive adhesive composition (B) of the weighted average molecular weight N _O-a of the total constituent monomer _units: average monomer structure of the total constituent monomer constituting the vinyl polymer (a) the number of oxygen atoms contained in the formula N _O-B: number of oxygen atoms contained averaged in the monomer structure of the total constituent monomer constituting the acrylic adhesive polymer (B) N _C-a: vinyl weight combined number of carbon atoms contained averaged in the monomer structure of the total constituent monomer constituting the (a) N _C-B: average single total constituent monomer constituting the acrylic adhesive polymer (B) Number of carbon atoms contained in the polymer structural formula

Further, the number of carbon atoms and oxygen calculated from the peak area ratios of O1s and C1s obtained by XPS measurement of a film obtained by drying each simple substance of the vinyl polymer (A) and the acrylic adhesive polymer (B). The ratio of the number of atoms is represented by the following formulas (2) and (3), respectively.

here,
(O / C) _A : 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 vinyl polymer (A).

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

The following formula (4) is derived from the above formulas (1) to (3), and the mass fraction of the vinyl polymer (A) with respect to the total amount of the vinyl polymer (A) and the acrylic adhesive polymer (B) is derived from this. _{(W a)} is calculated.

Further, values and the following formula of W _A obtained above (5), the mass fraction of the acrylic adhesive polymer (B) (W _B) is calculated.

here,
W _B: the mass fraction of the vinyl polymer (A) and an acrylic adhesive polymer to the total amount of the acrylic adhesive polymer (B) (B)

For Example 9, each element in the above formula (4) is shown below.
(O / C) _{A + B} : 0.316 (actual measurement value)
(O / C) _A : 0.290 (actual measurement value)
(O / C) _B : 0.465 (actual measurement value)
N _C-A: MMA1 number of carbon atoms in the molecule (5), from the number of carbon atoms (14) and the composition ratio in IBXMA1 molecule, 5 × 89.9 (mol%) + 14 × 10.1 (mol%) = 5.91
N _C-B: MEA1 number of carbon atoms in the molecule (6), the number of carbon atoms in HEA1 molecule (5), the number of carbon atoms in BA1 molecule (7) and than the composition ratio, 6 × 84.4 (mol% ) + 5 x 5.6 (mol%) + 7 x 10.1 (mol%) + 4 x 20.9 (mol%) = 6.05
M _w-A: Molecular weight of MMA (100), than the molecular weight of IBXMA (222) and the composition ratio, 100 × 89.9 (mol%) + 222 × 10.1 (mol%) = 112.3
M _w-B: molecular weight of MEA (130), the molecular weight of HEA (116), than the molecular weight of BA (128) and the composition ratio, 130 × 84.4 (mol%) + 116 × 5.6 (mol%) + 128 × 10.1 (mol%) = 119.6
_W A = 0.836 is obtained by substituting these values into equation _{(4), (5) W} B = 0.164 were obtained from the equation.

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 the surface layer portion] _{_{(K) = WA / Tg A}} + W B / Tg B (6)
here,
Tg _A : Tg (108 ° C.) of the vinyl polymer (A)
Tg _B : Tg (-35 ° C) of acrylic adhesive polymer (B)

<Vacuum compressed air forming test of decorative film>
An aluminum car shape of a vinyl chloride decorative film (manufactured by Nippon Wavelock Co., Ltd., 200 μm thick) with an adhesive sheet attached using a vacuum compressed air molding machine (manufactured by Navitas Co., Ltd., NATS-0612B type). It was molded into a model (manufactured by TP Giken Co., Ltd., 200 mm x 100 mm x 40 mm). The molding conditions were two-stage molding in which the decorative film was preliminarily shaped at a film heating temperature of 80 ° C. or 90 ° C., and then steam compressed air was performed at 130 ° C. for 15 seconds to adhere the decorative film to the car shape model. Then, the appearance of the vacuum-compressed decorative film was visually confirmed and evaluated according to the following criteria.
◯: No shock line Δ: 1 or 2 shock lines ×: 3 or more shock lines

Examples 2 to 13 and Comparative Examples 1 to 6
As shown in Tables 2 and 3, the same operation as in Example 1 was performed except that the composition of the pressure-sensitive adhesive composition, the type of the thin film layer, and the film thickness were changed, and vacuum compressed air molding was performed (however, however). In Comparative Examples 5 and 6, the thin film layer was not formed). The results are shown in Tables 2 and 3.

The numbers of each component of the pressure-sensitive adhesive composition in Tables 2 and 3 mean the parts by mass of the solid content. The abbreviations in Tables 2 and 3 mean the following.
◆ Crosslinking agent・ D-110N: Takenate D-110N manufactured by Mitsui Chemicals, trimethylolpropane adduct of metaxylylenediisocyanate, solid content concentration 75.0%, NCO content 11.5%
-CO-L: Coronate L manufactured by Tosoh Corporation, trimethylolpropane adduct of tolylene diisocyanate, solid content concentration 75.0%, NCO content 13.2%
◆ Polyolefin-based resin・ C-1: Acid-modified polyolefin-based resin, Toyobo PMA-T manufactured by Toyobo Co., Ltd., maleic anhydride-modified propylene / butene copolymer, degree of modification 1.5% by mass, weight average molecular weight 55, 000, melting point 95 ° C
C-4: Acid-modified polyolefin resin, Aronmelt PPET-1303S manufactured by Toagosei Co., Ltd., softening point 100 ° C.
C-6: Acid-modified polyolefin resin, Toyobo PMA-L manufactured by Toyobo Co., Ltd., maleic anhydride-modified propylene / butene copolymer, degree of modification 1.5% by mass, weight average molecular weight 75,000, melting point 70 ℃
C-7: Acid-modified polyolefin resin, Auroralen 200S manufactured by Nippon Paper Industries, Ltd., maleic anhydride-modified ethylene vinyl acetate, weight average molecular weight 65,000, melting point 60 to 70 ° C.
-C-8: Chlorinated polyolefin resin: Supercron 814HS manufactured by Nippon Paper Industries, Ltd., chlorinated propylene, chlorination modification degree 41% by mass, weight average molecular weight 20,000, melting point 65 ° C.
◆ Rosin ester resin・ C-2: Pine crystal KE-311 manufactured by Arakawa Chemical Industry Co., Ltd., softening point 90-100 ℃
◆ Polyester resin・ C-3: Aronmelt PES-320SK manufactured by Toagosei Co., Ltd., softening point 110 ℃
C-5: Plus Coat Z-730 manufactured by GOO CHEMICAL CO., LTD., Weight average molecular weight 3,000, softening point 80-85 ° C.

As is clear from the results of Examples 1 to 13, when the pressure-sensitive adhesive sheet of the present disclosure was applied to vacuum compressed air molding of a decorative film, the effect of suppressing shock lines was excellent (Table 2). Among these, it is calculated from Examples 1 to 5, 8, 9, 12, 13 in which the melting point, softening point or Tg of the thin film layer is more than 85 ° C., and the composition obtained by X-ray photoelectron spectroscopy of the thin film layer. In Example 11 in which the Tg was more than 85 ° C., the effect of suppressing the shock line was large.
On the other hand, in Comparative Examples 1 to 6 using the pressure-sensitive adhesive sheet without the thin film layer specified in the present disclosure, a shock line was generated, which was not suitable for vacuum compressed air molding (Table 3).

The adhesive sheet of the present disclosure can follow a complicated shape such as a curved surface or an uneven portion in vacuum compressed air molding of a decorative film, and can suppress the occurrence of a shock line. Therefore, the pressure-sensitive adhesive sheet of the present disclosure is suitable as a material for decorating various molded products such as resin products, metal products, ceramic products, and glass products. Specifically, home appliances; housing equipment such as toilets, bathrooms, doors, walls; automobile interior / exterior parts such as bumpers, dashboards, doors, roofs, bonnets; electronic parts, nursing / medical supplies, ship interior / exterior parts , Can be suitably used for manufacturing interior / exterior members of aircraft.

Claims

It has a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition and a thin film layer.
The thin film layer is arranged on at least one side of the pressure-sensitive adhesive layer, is thinner than the pressure-sensitive adhesive layer, and has a melting point, softening point, or glass transition temperature (Tg) of 70 ° C. or higher, or The thin film layer is a surface layer portion of the pressure-sensitive adhesive layer, and has a Tg of 70 ° C. or higher calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopic analysis of the pressure-sensitive adhesive layer. ..
The pressure-sensitive adhesive sheet for vacuum pressure molding according to claim 1, wherein the pressure-sensitive adhesive composition is an acrylic pressure-sensitive pressure-sensitive adhesive composition.
The acrylic pressure-sensitive adhesive composition contains a vinyl polymer (A) and an acrylic pressure-sensitive adhesive polymer (B).
The vinyl polymer (A) has a Tg of 30 ° C. or higher and 200 ° C. or lower, a number average molecular weight of 500 to 10,000, and is 0.5 with respect to 100 parts by mass of the acrylic adhesive polymer (B). It contains more than 60 parts by mass and less than 60 parts by mass.
In the pressure-sensitive adhesive layer, the first Tg, which is the Tg of the entire pressure-sensitive adhesive layer, is −80 ° C. or higher and 20 ° C. or lower.
The vacuum according to claim 2, wherein the second Tg, which is Tg calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive layer, is higher than the first Tg by 30 ° C. or more. Adhesive sheet for pressure molding.
The pressure-sensitive adhesive sheet for vacuum pressure molding according to claim 3, wherein the vinyl polymer (A) is contained in a higher concentration in at least one surface layer portion of the pressure-sensitive adhesive layer.
The method according to any one of claims 1 to 4, wherein the thin film layer contains at least one selected from the group consisting of a polyolefin resin, a rosin ester resin, a polyester resin and a (meth) acrylic resin. Adhesive sheet for vacuum pressure air forming.
The method for producing an adhesive sheet for vacuum compressed air molding according to any one of claims 1 to 5.
A method for producing an adhesive sheet for vacuum compressed air molding, in which the thin film layer is formed on a release film.
It is a method of manufacturing an adhesive sheet for vacuum compressed air molding.
The process of forming a thin film layer and
A step of applying the pressure-sensitive adhesive composition on the thin film layer to form a pressure-sensitive adhesive layer, and the like.
A method for producing a pressure-sensitive adhesive sheet for vacuum pressure molding, wherein the thin film layer is thinner than the pressure-sensitive adhesive layer, and the melting point, softening point, or glass transition temperature (Tg) of the thin film layer is 70 ° C. or higher.
A decorative film having an adhesive sheet for vacuum compressed air molding according to any one of claims 1 to 5.
A decorative molded body formed by attaching the decorative film according to claim 8 to the molded body.