JP6801266B2 - Decorative film and decorative molded body provided with it - Google Patents

Description

The present specification relates to a decorative film and a decorative molded product provided with the same. More specifically, the present invention relates to a decorative film having good adhesiveness under high temperature and high humidity, and a decorative molded product provided with the decorative film.

Adhesives (also referred to as pressure-sensitive adhesives) are processed into, for example, tapes, labels, and the like, 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.

Further, the adhesive is also used for a decorative film for the purpose of protecting members such as home appliances or automobile interior supplies and imparting design. The decorative film is produced by laminating a decorative layer, an adhesive layer, or the like on a base material layer made of a vinyl chloride resin, a polyolefin resin, or the like. A decorative film having such an adhesive layer is disclosed in Patent Document 1.

Patent Document 2 discloses a pressure-sensitive adhesive composition that exhibits good adhesiveness at high temperatures by segregating a vinyl polymer as a tack fire on the surface layer of the pressure-sensitive adhesive layer. It is described that this pressure-sensitive adhesive composition is used for a pressure-sensitive adhesive film, a pressure-sensitive adhesive sheet, a pressure-sensitive adhesive tape, a label, and the like.

Japanese Unexamined Patent Publication No. 2012-213894 Japanese Unexamined Patent Publication No. 2014-0885449

In the use of decorative films, it is required to have the ability to follow a complicated shape having curved surfaces and uneven portions and to exhibit good adhesiveness even under high temperature conditions. Furthermore, when a decorative film is attached to a plastic molded body, bubbles (foaming) are generated from the plastic substrate or the like by exposing it to high temperature and high humidity conditions for a long time, and it floats at the adhesive interface with the adhesive layer. Or peeling may occur. The decorative film is required to have excellent durability without causing such an appearance defect.

Although the decorative film of Patent Document 1 has good adhesiveness at room temperature, there are concerns about its performance such as adhesiveness at high temperature. Moreover, it is not sufficient in terms of adhesiveness to the curved surface portion.

The present specification provides a decorative film as a novel application of an adhesive composition, which is excellent in adhesiveness under high temperature and high humidity and adhesiveness to a curved surface and does not cause the above-mentioned problems, and the addition thereof. Provide a decorative molded body.

As a result of diligent studies in view of the above problems, the present inventors have focused on a pressure-sensitive adhesive composition containing an acrylic pressure-sensitive adhesive polymer and a low molecular weight vinyl polymer. That is, when a pressure-sensitive adhesive composition containing a predetermined acrylic pressure-sensitive adhesive polymer and a vinyl polymer having a predetermined molecular weight range is formed, the low-molecular-weight vinyl polymer is applied to the surface layer of the pressure-sensitive adhesive layer. I learned that it can be segregated. Then, as a new use of this pressure-sensitive adhesive composition, it was found that it can be used for a decorative film as described above. According to the present specification, the following means are provided.

[1] A decorative film comprising a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive composition containing a vinyl polymer (A) and an acrylic pressure-sensitive adhesive polymer (B) on at least one side of a base material.
The vinyl polymer (A) has a glass transition temperature (Tg) of 30 ° C. or higher and 200 ° C. or lower, a number average molecular weight of 500 to 10,000, and 100 parts by mass of the acrylic adhesive polymer (B). It is contained in an amount of 0.5 parts by mass or more and 60 parts by mass or less.
When the pressure-sensitive adhesive composition was applied to a separator and dried to obtain a pressure-sensitive adhesive layer, the first Tg, which is the glass transition temperature of the entire pressure-sensitive adhesive layer, was −80 ° C. or higher and 10 ° C. or lower.
The second Tg, which is the glass transition temperature calculated from the surface layer portion of the pressure-sensitive adhesive layer obtained by X-ray photoelectron spectroscopy, is 30 ° C. or more higher than the first Tg.
Decorative film.
[2] The acrylic adhesive polymer (B) according to [1], wherein the acrylic adhesive polymer (B) contains 85% by mass or more of structural units derived from (meth) acrylic acid alkoxyalkyl ester with respect to all the constituent monomers. Decorative film.
[3] The decorative film according to [1] or [2], wherein the haze value of the pressure-sensitive adhesive layer is 2.0 or less.
[4] The peel strength of the pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer having a thickness of 50 μm made of the pressure-sensitive adhesive composition on a 100 μm-thick polyethylene terephthalate film base material with respect to a polypropylene plate at 85 ° C. is 3.0 N / 25 mm or more. The decorative film according to any one of 1] to [3].
[5] A decorative molded body formed by attaching the decorative film according to any one of [1] to [4] to the molded body.

According to the decorative film provided with the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition disclosed in the present specification (hereinafter, also referred to as the present pressure-sensitive adhesive composition), the pressure-sensitive adhesive layer is subjected to high temperature and high humidity and with respect to a curved surface. Since it can exhibit sufficient adhesiveness, it can have practical adhesiveness. In addition, a decorative molded body provided with such a decorative film can be obtained.

The present specification relates to a decorative film having an adhesive layer having excellent adhesiveness under high temperature conditions and adhesiveness to a curved surface, and a decorative molded product having the same.

The present pressure-sensitive adhesive composition contains a vinyl polymer (A) and an acrylic pressure-sensitive adhesive polymer (B) having a constant glass transition temperature and a number average molecular weight, and the vinyl polymer (A) is used as a surface layer of the pressure-sensitive adhesive layer. The glass transition temperature of the surface layer of the pressure-sensitive adhesive layer can be controlled by segregating to. The pressure-sensitive adhesive layer obtained from the present pressure-sensitive adhesive composition has excellent adhesiveness under high temperature and high humidity conditions, as well as excellent curved surface adhesiveness and durability.

The segregation behavior of the vinyl polymer (A) on the surface layer of the pressure-sensitive adhesive layer when the pressure-sensitive adhesive layer is formed with the present pressure-sensitive adhesive composition is different from that of the specific vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B). ) And are not completely compatible, but not completely separated. Preferably, the vinyl polymer (A) has a lower polarity than the acrylic adhesive polymer (B).

As described above, the pressure-sensitive adhesive composition uses a vinyl polymer (A) that is completely incompatible with the acrylic pressure-sensitive 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 may be 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 pressure-sensitive 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.

Further, such a pressure-sensitive adhesive layer according to the present pressure-sensitive adhesive composition can suppress floating and peeling of the pressure-sensitive adhesive layer even if there is outgas from the adherend at a high temperature, and can exhibit good adhesive durability.

The segregation of the vinyl polymer (A) occurs when the pressure-sensitive adhesive layer is formed, and the vinyl polymer (A) segregates on the surface layer side (air interface side) where the solvent evaporates. Therefore, for example, in the sheet-like or film-like pressure-sensitive adhesive layer of the present pressure-sensitive adhesive composition, when two surface layers facing each other in the thickness direction come into contact with a substance having a low surface energy such as a gas or a certain solid, such a substance A pressure-sensitive adhesive layer containing a vinyl polymer (A) at a higher concentration on the low surface energy interface side in contact with the pressure-sensitive adhesive layer, while containing a vinyl polymer (A) at a lower concentration on the center side in the thickness direction of the pressure-sensitive adhesive layer. Obtainable. That is, it is possible to obtain a pressure-sensitive adhesive layer having a gradient composition in which the vinyl polymer (A) is contained in a higher concentration on the surface layer side of the pressure-sensitive adhesive layer. From the viewpoint of the acrylic adhesive polymer (B), it is possible to obtain an adhesive layer having a inclined composition having the acrylic adhesive polymer (B) at a lower concentration on the surface layer side of the adhesive layer.

For example, in the sheet-like or film-like pressure-sensitive adhesive layer of the present pressure-sensitive adhesive composition, when only one surface of two surface layers facing each other in the thickness direction is on the low surface energy interface side, the vinyl weight is on the interface side. A pressure-sensitive adhesive layer containing the coalescence (A) at a higher concentration can be obtained.

In this pressure-sensitive adhesive composition, as a result of segregation of the vinyl polymer (A) in the pressure-sensitive adhesive layer, Tg calculated from the composition of the surface layer portion obtained by X-ray photoelectron spectroscopy of the pressure-sensitive adhesive layer is the entire pressure-sensitive adhesive layer. It can be higher than Tg of 30 ° C. or more. 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. For example, it is possible to suppress the floating and peeling of the adhesive layer even at a high temperature, and it is possible to exhibit good durability. In addition, it can have good adhesiveness to a curved surface.

Hereinafter, the disclosure of 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 present pressure-sensitive adhesive composition contains a vinyl polymer (A) and an acrylic pressure-sensitive adhesive polymer (B). Details of the vinyl polymer (A), the acrylic adhesive polymer (B), and the pressure-sensitive adhesive composition containing these will be described in order below.

[Vinyl polymer (A)]
The vinyl polymer (A) disclosed in the present specification can be a polymer having a glass transition temperature (Tg) of 30 ° C. or higher and 200 ° C. or lower. The lower limit of Tg is preferably 40 ° C. or higher, more preferably 50 ° C. or higher, still more preferably 60 ° C. or higher, still more preferably 70 ° C. or higher. The upper limit of Tg is 180 ° C. or lower, more preferably 150 ° C. or lower, still more preferably 120 ° C. or lower, still more preferably 110 ° C. or lower, still more preferably 100 ° C. or lower. The more preferable range of Tg is 50 ° C. or higher and 180 ° C. or lower, and more preferably 60 ° C. or higher and 150 ° C. or lower. In the present specification, 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, due to restrictions on the raw material monomer and the like, Tg generally does not exceed 200 ° C.

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 use (meth) acrylic acid-based compounds as main components because appropriate compatibility with acrylic-based adhesive polymers can be obtained. The specific amount of the (meth) acrylic acid-based compound used is preferably in the range of 10% by mass or more and 100% by mass or less. It is more preferably in the range of 30% by mass or more and 95% by mass or less, and further preferably in the range of 50% by mass or more and 90% 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, (meth) acrylic acid can be set to a relatively high Tg, has a high effect of suppressing floating and peeling of the adhesive sheet, and has good adhesion to an olefin-based adherend. It is preferable to use an aliphatic ring-based vinyl monomer such as isobornyl, dicyclopentanyl (meth) acrylate, cyclohexyl (meth) acrylate and adamantyl (meth) acrylate. The specific amount of the aliphatic ring-based vinyl monomer used is preferably in the range of 10% by mass or more and 90% by mass or less, and 20% by mass or more and 80% by mass with respect to the total constituent monomers of the vinyl polymer (A). % Or less is more preferable, and 30% 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. The specific amount of the aromatic vinyl compound used is preferably in the range of 1% by mass or more and 40% by mass or less with respect to the total constituent monomers of the vinyl polymer (A), and more preferably 5% by mass or more and 30% by mass or less. It is preferable, 5% by mass or more and 20% by mass or less is more 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. , Mono (meth) acrylic acid ester of polyalkylene glycol such as 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 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, ( 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, N-methylol (meth) acrylamide and the like. 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- Examples thereof include (n-butoxy) propyl and the like. These compounds may be used alone or in combination of two or more.

Examples of the cyano group-containing unsaturated compound include cyanomethyl (meth) acrylate, 1-cyanoethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, 1-cyanopropyl (meth) acrylate, and (meth) acrylic. 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, etacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-chloroacrylonitrile, α-fluoroacrylonitrile and the like. These compounds may be used alone or in combination of two or more.

Examples of 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. It is preferably 500 or more and 7,000 or less, and more preferably 1,000 or more and 5,000 or less. If Mn exceeds 10,000, the compatibility with the acrylic adhesive polymer (B) becomes poor. On the other hand, in order to produce a polymer having a Mn of less than 500, there are problems such as the need to use a large amount of a polymerization initiator and a chain transfer agent, and a decrease in productivity.

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 of 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.

As the initiator used in the present specification, an azo compound, an organic peroxide, an inorganic peroxide and the like can be used, but the initiator 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.

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.

[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. The glass transition temperature (Tg) of the acrylic adhesive polymer (B) is preferably a polymer having adhesiveness in the range of −80 ° C. or higher and 0 ° C. or lower, and preferably in the range of −80 ° C. or higher and −20 ° C. or lower. Is more preferable, and a range of −80 ° C. or higher and −30 ° C. or lower is further preferable. It is preferably in the range of −80 ° C. or higher and −40 ° C. or lower. When the Tg is less than −80 ° C., the cohesive force of the obtained pressure-sensitive adhesive layer becomes insufficient, and the curved surface adhesiveness tends to deteriorate. When Tg exceeds 0 ° C., the step followability and the adhesive strength at low temperature may not be sufficient.

Further, the acrylic adhesive polymer (B) preferably has a weight average molecular weight (Mw) of 100,000 or more from the viewpoint of exhibiting sufficient cohesive force and good adhesiveness. It is more preferably 250,000 or more, still more preferably 400,000 or more. On the other hand, if the weight average molecular weight is too large, the step followability tends to decrease, and it becomes difficult to handle in manufacturing. Therefore, the upper limit is preferably 2,000,000 or less. It is more preferably 1500,000 or less, still more preferably 1,000,000 or less.

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

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

Examples of the (meth) alkoxyalkyl (meth) acrylate having an alkoxyalkyl group having 2 to 12 carbon atoms include methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, butoxymethyl (meth) acrylate, and (meth). Examples thereof include methoxyethyl 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 4 to 12 carbon atoms and / or the (meth) acrylic acid alkoxyalkyl having an alkoxyalkyl group having 2 to 12 carbon atoms is the total amount of the acrylic copolymer. It is preferably 30% by mass or more and 100% by mass or less, and more preferably 50% by mass or more and 99% by mass or less based on the constituent monomers. If it is less than 30% by mass, the adhesive strength, initial adhesive strength (tack), low temperature adhesiveness, etc. of the obtained pressure-sensitive adhesive composition will be insufficient.

Further, among the above, alkoxyalkyl (meth) acrylate is more preferable in that the vinyl polymer (A) easily segregates on the surface layer of the pressure-sensitive adhesive layer while exhibiting good adhesive performance. The amount of the (meth) acrylic acid alkoxyalkyl ester used is preferably 40% by mass or more, more preferably 45% by mass or more, and further preferably 50% by mass or more. Further, it is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and still more preferably 85% by mass or more. Further, it is preferably 90% by mass or more, more preferably 92% by mass or more, and further preferably 95% by mass or more. The upper limit of the amount of the (meth) acrylic acid alkoxyalkyl ester used is 100% by mass.

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. Hydroxylate-containing 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 acrylamide. , N-methoxymethylacrylamide, N-methoxybutylacrylamide and other ethylene-based unsaturated carboxylic acid amides and N-substituted compounds; unsaturated alcohols such as allyl alcohol; (meth) acrylonitrile, vinyl acetate, glycidyl (meth) acrylate, Examples thereof include diacetone acrylamide, and one or more of these can be used.

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

Examples of the polyfunctional (meth) acrylate compound include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and polypropylene glycol di (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; methylene. 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.

[Adhesive composition]
The pressure-sensitive adhesive composition can contain a vinyl polymer (A) and an acrylic pressure-sensitive adhesive polymer (B). The vinyl polymer (A) has an appropriate compatibility with the acrylic adhesive polymer (B). Therefore, the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition containing these exhibits good transparency, and the vinyl polymer (A) is partially segregated in the pressure-sensitive adhesive layer, and the vinyl polymer (A) on the surface layer thereof is segregated. ) May be higher than other parts.

As described above, when the concentration of the vinyl polymer (A) on the surface layer of the pressure-sensitive adhesive layer is higher than that of the others, it has sufficient curved surface adhesiveness. Further, since the pressure-sensitive adhesive layer near the bonding interface has a relatively high Tg, good adhesiveness can be exhibited even under high temperature conditions. In addition, floating and peeling of the adhesive sheet due to outgas generated from the adherend is suppressed. 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.

The present pressure-sensitive adhesive composition can contain the vinyl polymer (A) 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) in terms of solid content. 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.

[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 a glycidyl compound having two or more glycidyl 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, a glycidyl 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, and 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 glycidyl compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexanediol di. Glycidyl ether, tetraglycidyl xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, trimethylolpropane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, etc. Examples include polyfunctional glycidyl compounds.

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.

[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 formed from the pressure-sensitive adhesive composition, that is, the first Tg can be in the range of −80 ° C. or higher and 10 ° C. or lower. The preferable lower limit is −70 ° C. or higher, and more preferably −60 ° C. or higher. The upper limit is preferably 0 ° C. or lower, more preferably −10 ° C. or lower, and even more preferably −20 ° C. or lower. The preferred range is −70 ° C. or higher and −20 ° 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 adhesiveness to curved surfaces tends to deteriorate. When the first Tg exceeds 10 ° C, the step followability and low temperature conditions Adhesive strength underneath may not be sufficient. The Tg of the present pressure-sensitive adhesive composition can be obtained by DSC with a temperature rising 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]
The second Tg of the pressure-sensitive adhesive composition, that is, the pressure-sensitive adhesive composition obtained by X-ray photoelectron spectroscopic analysis of the pressure-sensitive adhesive layer when the pressure-sensitive adhesive composition is applied to a separator and dried to obtain a pressure-sensitive adhesive layer. The Tg calculated from the composition of the surface layer portion is calculated 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 5 nm. The details of the measurement method can follow the operations described in Examples described later.

The second Tg is not particularly limited, but is preferably 0 ° C. or higher. When the second Tg is 0 ° C. or higher, the Tg difference described below can be easily obtained, and as a result, not only the curved surface adhesiveness but also the high temperature adhesiveness and durability of the adherend can be ensured. The second Tg is more preferably 10 ° C. or higher, further preferably 25 ° C. or higher, and even more preferably 40 ° 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.

[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, even when a transparent plastic substrate such as polypropylene or polycarbonate is used as an adherend and exposed to high temperature and high humidity. , Floating and peeling at the adhesive interface with the pressure-sensitive adhesive layer due to air bubbles (foaming) generated from a plastic substrate or the like are suppressed, and good durability (foaming resistance) is exhibited.

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 230 ° 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 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. It is more preferably 60% or more, further preferably 65% or more, still more preferably 70% or more, still more preferably 75% or more, and even more preferably 80% or more. The mass fraction is preferably 90% or less, more preferably 85% or less.

[Adhesiveness (peeling strength)]
The present pressure-sensitive adhesive composition is a polypropylene (PP) plate at 85 ° C. and a peeling speed of 300 mm / min for a pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer having a thickness of 50 μm and a 100 μ-thick polyethylene terephthalate film base material. The adhesive strength with respect to the adhesive is preferably 3.0 N / 25 mm or more. By setting the adhesive strength under the high temperature condition of 85 ° C. to 3.0 N / 25 mm or more, the adhesive strength to the PP plate under the high temperature and high humidity condition is sufficiently high, so that the adhesive sheet does not float or peel off. Prevention and good curved surface adhesiveness can be ensured. It is more preferably 3.5 N / 25 mm or more, and further preferably 4.0 N / 25 mm or more.

Here, in producing the adhesive layer (adhesive sheet), a method of directly coating the adhesive composition on a polyester film base material and drying it to obtain an adhesive sheet, or once coating on a paper pattern or the like. After the work, any method of transfer to the polyester film base material may be adopted. Drying may be performed at room temperature, but from the viewpoint of productivity and the like, it is usually dried using a dryer under heating conditions of 40 to 150 ° C. for several seconds to several tens of minutes. The method is common. More specifically, the present pressure-sensitive adhesive composition is applied to a PET film separator so that the thickness after drying is 50 μm, and then dried at 80 ° C. for 4 minutes to remove ethyl acetate. A PET separator having a thickness of 38 μm, which has a different peeling power from that of the separator, is attached and allowed to stand at 40 ° C. for 5 days to prepare an adhesive film sample for measuring peel strength with a double-sided separator. Obtainable.

In measuring the peel strength, the adhesive film sample was further transferred to a PET film (100 μm) that had been easily adhered to obtain an adhesive sheet for evaluation, which was used as a PP plate (manufactured by Sumitomo Noblen, Noblen MHB, 2 mm thick). After adhering the adhesive sheets and crimping them for 20 minutes under the conditions of 0.5 MPa and 50 ° C. using a desktop pressure defoaming device TBR-200 (manufactured by Chiyoda Electric Industry Co., Ltd.), for example, a tensile tester with a constant temperature bath, Stro. Using a graph R type (manufactured by Toyo Seiki Co., Ltd.), measure the 180-degree peel strength of the adhesive sheet under the conditions of 23 ° C or 85 ° C according to JISZ-0237 "Adhesive Tape / Adhesive Sheet Test Method" and bond. Can be strength.

The pressure-sensitive adhesive layer according to the pressure-sensitive adhesive composition has high adhesiveness to polypropylene as an adherend at high temperatures, and these characteristics are based on the Tg composition (distribution) of the pressure-sensitive adhesive layer. Therefore, high-temperature adhesiveness can be provided regardless of the type of material of the adherend.

[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. As described above, the pressure-sensitive adhesive layer obtained from the present pressure-sensitive adhesive composition has an appropriate compatibility with the acrylic pressure-sensitive adhesive polymer (B) because the vinyl polymer (A) has an appropriate compatibility with the acrylic pressure-sensitive adhesive polymer (B). Shows good transparency.

The haze value can be evaluated by, for example, the following method. That is, one separator is peeled off from the pressure-sensitive adhesive film sample according to the present pressure-sensitive adhesive composition, 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, and the haze meter is operated. Use to measure haze values. 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.

[Foam resistance]
The pressure-sensitive adhesive layer obtained by the present pressure-sensitive adhesive composition has a relatively high Tg on the surface layer of the pressure-sensitive adhesive layer, and is excellent in adhesiveness at the interface with an adherend. Therefore, even if gas is generated from the adherend, the adhesive layer is suppressed from floating or peeling.

For example, the foam resistance can be evaluated by the following method. That is, a laminate in which a PET film having a thickness of 100 μm and having been easily adhered is attached to one side of an adhesive film sample using the present adhesive composition, and an adherend (PP plate or polycarbonate (PC) plate) is attached to the other surface. After preparing the body and crimping it at 50 ° C. for 0.5 MPa for 20 minutes, the laminate was loaded for 24 hours in a constant temperature and humidity chamber at 60 ° C./90%, and the appearance after loading was observed. Appropriately determine the ratio of the foamed area to the total area. For example, the foam resistance is evaluated based on the presence or absence of a change in appearance and the foaming area of 10% of the total.

In addition to the vinyl polymer (A) as a tack fire and the acrylic adhesive polymer (B), the present pressure-sensitive adhesive composition can be used as a tackifier, a plasticizer, an antioxidant, an ultraviolet absorber, and aging, if necessary. The composition may also contain additives such as an inhibitor, a flame retardant, a fungicide, a silane coupling agent, a filler, and a colorant.

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 and the like. 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.

Examples of the plasticizing agent 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; azelaic 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.

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 trione 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.

Examples of the ultraviolet absorber include salicylic acid-based ultraviolet absorbers such as phenylsalicylate, p-tert-butylphenylsalicylate, and p-octylphenylsalicylate; 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 UV absorbers such as -5-sulfobenzophenone, 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- Cyanoacrylate-based ultraviolet absorbers such as cyano-3,3'-diphenylacrylate; nickel bis (octylphenyl) sulfate, [2,2'-thiobis (4-tert-octylphenolate)]-n-butylamine nickel, nickel Complex-3,5-di-t Examples thereof include nickel-based ultraviolet stabilizers such as ert-butyl-4-hydroxybenzyl-phosphate monoethylate and nickel-dibutyldithiocarbamate.

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, 2-mercaptobenzimidazole zinc salt, 2-mercaptomethylbenzimidazole, nickel dibutyldithiocarbamate, tris (nonylphenyl) phosphite, dilauryl thiodipropionate, dithiodipropionate Examples include stearyl and the like.

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.

Examples of the fungicide include benzimidazole, benzothiazole, trihaloallyl, triazole, and organic nitrogen sulfur compounds.

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.

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.

The form of the pressure-sensitive adhesive composition is not particularly limited as long as it contains the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B). 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 80 parts by mass with respect to 100 parts by mass 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 trimethylolpropane tri (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.

[Manufacturing of adhesive composition]
As long as the present pressure-sensitive adhesive composition contains a specified amount of the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B), there are no particular restrictions on the mixing method. For example, the vinyl acetate polymer (A) and the acrylic adhesive polymer (B) may be mixed to obtain the present pressure-sensitive adhesive composition, or the acrylic adhesive polymer (B) may be mixed in the presence of the vinyl polymer (A). ) May be polymerized to obtain the present pressure-sensitive adhesive composition.

The present pressure-sensitive adhesive composition can be obtained by adjusting the Tg (first Tg) of the entire pressure-sensitive adhesive layer and the Tg (second Tg) of the surface layer of the pressure-sensitive adhesive layer at the time of forming the pressure-sensitive adhesive layer. That is, those skilled in the art will use the first Tg, the second Tg, and the temperature difference between them in order to realize the adhesiveness of the pressure-sensitive adhesive layer that is finally obtained. The present pressure-sensitive adhesive composition can be obtained by appropriately selecting and blending a vinyl polymer (A), an acrylic pressure-sensitive adhesive polymer (B), and the like based on the teachings.

In the present pressure-sensitive adhesive composition, for example, a vinyl polymer (A) is dissolved in a solvent such as ethyl acetate to prepare a polymer solution, and a polymer of an acrylic adhesive polymer (B) is added to the polymer solution. The solution can be mixed, and if necessary, a cross-linking agent can be mixed to produce the product.

[Decorative film]
The pressure-sensitive adhesive composition can form a pressure-sensitive adhesive layer of a decorative film. The decorative film provided with the pressure-sensitive adhesive layer obtained from the present pressure-sensitive adhesive composition can exhibit sufficient adhesiveness under high temperature and high humidity and on curved surfaces.

That is, the pressure-sensitive adhesive layer included in the decorative film includes a composition derived from the pressure-sensitive adhesive composition, a first Tg of the entire pressure-sensitive adhesive layer, and a second Tg calculated from the composition of the surface layer portion of the pressure-sensitive adhesive layer. These temperature differences can be provided. More preferably, it can have the above-mentioned peel strength.

The present decorative film may be provided with a decorative layer and a base material layer in this order in addition to the adhesive layer described above.

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 polyethylene terephthalate (PET) resin, acrylic resin, ABS resin, polycarbonate resin, polypropylene resin, and polyethylene resin. Of these, PET resin is preferable as the material used for the base material layer.

The thickness of the base material layer is preferably 25 μm to 300 μm, more preferably 50 μm to 200 μm. When the thickness of the base material layer is within the above range, the processability, shape followability, and handleability are good when the decorative molded product is manufactured by the vacuum forming 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, and 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 5 to 40 μm, more preferably 5 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.

The decorative film disclosed herein may further include 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.

[Decorative molding]
The present specification can provide a decorative molded article (hereinafter, also referred to as the present decorative molded article) including the decorative film disclosed in the present specification. Since the decorative molded product includes a decorative film provided with an adhesive layer obtained from the adhesive composition, it does not float or peel off even when exposed to high temperature and high humidity, and has excellent durability. ..

The molded body to which the decorative film is adhered is not particularly limited, and may be, for example, an article to which the decorative film can be adhered, such as home appliances, automobile interior parts, and miscellaneous goods.

A vacuum forming method or an injection molding method can be used for manufacturing the present decorative molded body. In the vacuum forming method, the decorative film is stretched while being heated and softened, the space on the molded body side of the decorative film is depressurized, and the space on the opposite side is pressurized as necessary to form the molded product. Adhere while molding along the surface shape of. In the injection molding method, the decorative film is set in the mold cavity of the injection molding machine, and injection molding is performed to bond the decorative film along the surface shape of the molded body. By these methods, the present decorative molded article can be obtained.

Hereinafter, specific examples embodying the disclosure of the present 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-SuperMP-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 point (Tg)>
The Tg of the vinyl polymer (A), the acrylic adhesive polymer (B) and the pressure-sensitive adhesive composition was measured by DSC under the following conditions.
DSC: Made by TA Instrument (Q-100)
Temperature rise temperature: 10 ° C / min Measurement atmosphere: Nitrogen

<Polymer composition>
The polymer composition was calculated from the amount of monomer charged and the amount of monomer consumed by 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 Synthesis Example 1 (Synthesis of Polymer A-1)
In a four-necked flask with an internal volume of 1 liter, 45 parts by mass of methyl methacrylate (MMA), 5 parts by mass of styrene (St), 245 parts by mass of butyl acetate, and dimethyl 2,2'-azobis (2-methylpropionate) ( A mixed solution consisting of V-601) 2.7 parts by mass manufactured by Wako Pure Chemical Industries, Ltd. 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, polymerization was carried out by dropping a mixed solution consisting of 180 parts by mass of MMA, 19 parts by mass of St, 24 parts by mass of V-601 and 90 parts by mass of butyl acetate from the dropping funnel into the flask over 5 hours. After completion of the dropping, the polymerization solution was added dropwise to 6000 parts by mass of hexane to isolate the vinyl polymer in the polymerization solution, and the polymer A-1 was obtained. The polymer composition of the obtained polymer A-1 was MW5650, Mn3270, and Mw / Mn1.73, which consisted of 90% by mass of MMA and 10% by mass of St as a result of calculation from the amount charged and the amount of monomer consumed by GC measurement. Tg was 80 ° C.
The composition and analysis results of polymer A-1 are shown in Table 1.

Synthesis Example 2 (Synthesis of Polymer A-2)
A mixed solution consisting of 200 parts by mass of butyl acetate and 4.1 parts by mass of V-601 was charged into a four-necked flask having an internal volume of 1 liter, and the mixed solution was sufficiently degassed by bubbling nitrogen gas to prepare the mixed solution. The internal temperature was raised to 90 ° C. Separately, polymerization is carried out by dropping a mixed solution consisting of 114 parts by mass of MMA, 140 parts by mass of isobornyl methacrylate (IBXMA), 78 parts by mass of V-601 and 90 parts by mass of butyl acetate from the dropping funnel into the flask over 5 hours. It was. After completion of the dropping, the polymerization solution was added dropwise to a mixed solution consisting of 2800 parts by mass of methanol and 700 parts by mass of distilled water to isolate the vinyl polymer in the polymerization solution to obtain polymer A-2.
The composition and analysis results of polymer A-2 are shown in Table 1.

Synthesis Example 3 (Synthesis of Polymer A-3)
A four-necked flask having an internal volume of 0.5 liter is charged with a mixed solution consisting of 75 parts by mass of butyl acetate and 1.7 parts by mass of V-601, and the mixed solution is sufficiently degassed by bubbling nitrogen gas and mixed. The internal temperature of the liquid was raised to 90 ° C. Separately, polymerization was carried out by dropping a mixed solution consisting of 80 parts by mass of MMA, 63 parts by mass of IBXMA, 33 parts by mass of V-601 and 90 parts by mass of butyl acetate from the dropping funnel into the flask over 5 hours. After completion of the dropping, the polymerization solution was added dropwise to a mixed solution consisting of 2800 parts by mass of methanol and 700 parts by mass of distilled water to isolate the vinyl polymer in the polymerization solution to obtain polymer A-3.
The composition and analysis results of polymer A-3 are shown in Table 1.

Synthesis Example 4 (Synthesis of Polymer A-4)
A mixed solution consisting of 200 parts by mass of butyl acetate and 4.0 parts by mass of V-601 was charged into a four-necked flask having an internal volume of 1 liter, and the mixed solution was sufficiently degassed by bubbling nitrogen gas to prepare the mixed solution. The internal temperature was raised to 90 ° C. Separately, polymerization was carried out by dropping a mixed solution consisting of 59 parts by mass of MMA, 200 parts by mass of IBXMA, 75 parts by mass of V-601 and 90 parts by mass of butyl acetate from the dropping funnel into the flask over 5 hours. After completion of the dropping, the polymerization solution was added dropwise to a mixed solution consisting of 2800 parts by mass of methanol and 700 parts by mass of distilled water to isolate vinyl polymerization in the polymerization solution to obtain polymer A-4.
The composition and analysis results of polymer A-4 are shown in Table 1.

Synthesis Example 5 (Synthesis of Polymer A-5)
A mixed solution consisting of 230 parts by mass of butyl acetate, 50 parts by mass of MMA, and 11.6 parts by mass of V-601 was charged into a four-necked flask having an internal volume of 1 liter, and the mixed solution was sufficiently degassed by bubbling nitrogen gas. , The internal temperature of the mixed solution was raised to 90 ° C. Separately, polymerization was carried out by dropping a mixed solution consisting of 200 parts by mass of MMA, 46 parts by mass of V-601 and 90 parts by mass of butyl acetate from the dropping funnel into the flask over 5 hours. After completion of the dropping, the polymerization solution was added dropwise to 6000 parts by mass of hexane to isolate the vinyl polymer in the polymerization solution to obtain polymer A-5.
The composition of polymer A-5 and the analysis results are shown in Table 1.

2. 2. Synthesis of Acrylic Adhesive Polymer Synthesis Example 6 (Synthesis of Polymer B-1)
In a four-necked flask having an internal volume of 2 liters, 285 parts by mass of methoxyethyl acrylate (MEA), 15 parts by mass of 2-hydroxyethyl acrylate (HEA), and 520 parts by mass of ethyl acetate were charged, and the mixed solution was mixed with nitrogen gas. The mixture was sufficiently degassed by bubbling, the internal temperature of the mixed solution was raised to 40 ° C., 11.5 parts by mass of azobisvaleronitrile (V-65) was charged, and polymerization was started. After 4 hours, the polymerization solution was added dropwise to 10000 parts by mass of hexane to isolate an acrylic adhesive polymer, and a polymer B-1 was obtained. The obtained polymer B-1 consisted of 95% by mass of MEA and 5% by mass of HEA, and had Mw500,000, Mn70000, and Mw / Mn7.1.
The composition of polymer B-1 and the analysis results are shown in Table 2.

Synthesis Example 7 (Synthesis of Polymer B-2)
A four-necked flask having an internal volume of 2 liters was charged with 255 parts by mass of MEA, 8 parts by mass of butyl acrylate (BA), 15 parts by mass of HEA, and 520 parts by mass of ethyl acetate, and the mixed solution was sufficiently degassed by bubbling nitrogen gas. Then, the internal temperature of the mixed solution was raised to 40 ° C., 11.4 parts by mass of V-65 was charged, and polymerization was started. After 4 hours, the polymerization solution was added dropwise to 10000 parts by mass of hexane to isolate an acrylic adhesive polymer, and a polymer B-2 was obtained. The obtained polymer B-2 consisted of 85% by mass of MEA, 10% by mass of BA, and 5% by mass of HEA, and was Mw520000, Mn80000, and Mw / Mn6.5.
The composition and analysis results of polymer B-2 are shown in Table 2.

Synthesis Example 8 (Synthesis of Polymer B-3)
MEA188 parts by mass, BA192 parts by mass, HEA 20 parts by mass, and ethyl acetate 740 parts by mass were charged into a four-necked flask having an internal volume of 2 liters, and the mixed solution was sufficiently degassed by bubbling nitrogen gas to contain the mixed solution. The temperature was raised to 40 ° C., 10.3 parts by mass of V-65 was charged, and polymerization was started. After 4 hours, the polymerization solution was added dropwise to 10000 parts by mass of hexane to isolate an acrylic adhesive polymer, and a polymer B-3 was obtained. The obtained polymer B-3 consisted of 47% by mass of MEA, 48% by mass of BA, and 5% by mass of HEA, and was Mw510000, Mn90000, and Mw / Mn5.7.
The composition and analysis results of polymer B-3 are shown in Table 2.

3. 3. Production and Evaluation of Adhesive Composition Example 1
The polymer A-1 obtained in Synthesis Example 1 was dissolved in ethyl acetate to prepare a polymer A-1 solution having a solid content concentration of 30% by mass. Similarly, the polymer (B-1) obtained in Synthesis Example 6 was dissolved in ethyl acetate to prepare a polymer (B-1) solution having a solid content concentration of 30% by mass. 4 parts by mass of the polymer A-1 solution, 100 parts by mass of the polymer B-1 solution, and 0.16 part by mass of Takenate D-110N (solid content concentration 75% by mass, manufactured by Mitsui Chemicals, Inc.) as a cross-linking agent were mixed. A pressure-sensitive adhesive composition was obtained.

This pressure-sensitive adhesive composition was applied onto a polyethylene terephthalate (PET) separator having a thickness of 38 μm so as to have a thickness of 50 μm after drying. Ethyl acetate is removed and a cross-linking reaction is carried out by drying the pressure-sensitive adhesive composition at 80 ° C. for 4 minutes, and a PET separator having a thickness of 38 μm, which has a different peeling power from the separator, is attached and 5 at 40 ° C. An adhesive film sample with a double-sided separator was obtained by allowing it to stand for a day and aging.

The obtained adhesive film sample was subjected to various measurements and evaluations by the following methods. The results obtained are shown in Table 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 film sample, 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 weight and the weight of the balance, the gel fraction with respect to the acrylic adhesive polymer (B) was calculated by the following formula.
Gel fraction (%) = (weight of residue) / [(initial weight) 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 film sample, 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., and the transparency in the compounding composition thereof. Was evaluated.

<Peeling strength against polypropylene (PP)>
The pressure-sensitive adhesive film sample was transferred to a PET film (100 μm) that had been easily bonded to obtain a pressure-sensitive adhesive sheet for evaluation. The adherend was a PP plate (manufactured by Sumitomo Noblen, Noblen MHB, 2 mm thick), an adhesive sheet for the above evaluation was attached, and a desktop pressure defoaming device TBR-200 (manufactured by Chiyoda Denki Kogyo Co., Ltd.) was used. After crimping for 20 minutes under the conditions of 5 MPa and 50 ° C., using a tensile tester Strograph R type (manufactured by Toyo Seiki Co., Ltd.) with a constant temperature bath, JIS Z-0237 "adhesive tape" under the conditions of 23 ° C. and 85 ° C. The 180-degree peel strength of the adhesive sheet was measured according to "Adhesive sheet test method" and used as the adhesive strength. The peeling speed was set to 300 mm / min.

<Tg on the surface layer of the adhesive layer>
From the peak area ratio of O1s to C1s measured by X-ray photoelectron spectrometer (XPS) of the adhesive film sample, vinyl relative to the total amount of vinyl polymer (A) and acrylic adhesive polymer (B) in the surface layer portion of the adhesive layer. The mass fractions (w _A and w _B ) of the polymer (A) and the acrylic adhesive polymer ( _B ) were 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)

ここで、
（Ｏ／Ｃ）_Ａ+B：粘着剤組成物を乾燥して得られた粘着剤層のＸＰＳ測定から求められるＯ１ｓとＣ１ｓのピーク面積比
Ｗ_Ａ：ビニル重合体（Ａ）及びアクリル系粘着性ポリマー（Ｂ）の総量に対するビニル重合体（Ａ）の質量分率
Ｍ_ｗ−Ａ：ビニル重合体（Ａ）の全構成単量体単位の加重平均分子量
Ｍ_ｗ−Ｂ：アクリル系粘着剤組成物（Ｂ）の全構成単量体単位の加重平均分子量
Ｎ_Ｏ−Ａ：ビニル重合体（Ａ）を構成する全構成単量体の平均単量体構造式中に含まれる酸素原子数
Ｎ_Ｏ−Ｂ：アクリル系粘着性ポリマー（Ｂ）を構成する全構成単量体の平均単量体構造式中に含まれる酸素原子数
Ｎ_Ｃ−Ａ：ビニル重合体（Ａ）を構成する全構成単量体の平均単量体構造式中に含まれる炭素原子数
Ｎ_Ｃ−Ｂ：アクリル系粘着性ポリマー（Ｂ）を構成する全構成単量体の平均単量体構造式中に含まれる炭素原子数 The specific calculation method of the mass fraction will be described below.
The peak area ratio of O1s to C1s measured by XPS is the surface layer portion of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition composed of the vinyl polymer (A) and the acrylic pressure-sensitive adhesive polymer (B) as shown in the following formula (1). It is expressed by the ratio of the number of oxygen atoms and the number of carbon atoms present per unit weight of.

here,
_{(O / C) A + B} : O1s and C1s peak area ratio obtained from the XPS measurement of the adhesive composition and dried to obtained adhesive layer W _A: vinyl polymer (A) and the acrylic adhesive Weight fraction of vinyl polymer (A) with respect to total amount of polymer (B) M _w-A : 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: a vinyl polymer (a) the number of oxygen atoms contained averaged in the monomer structure of the total constituent monomer constituting the N _{O- B:} acrylic adhesive polymer number of oxygen atoms contained in all the structural during monomer average monomer structural formula of which constitutes the (B) N _C-a: all the structural monomers constituting the vinyl polymer (a) Number of carbon atoms contained in the average monomer structural formula of the body _NC-B : Number of carbon atoms contained in the average monomer structural formula of all the constituent monomers constituting the acrylic adhesive polymer (B)

ここで、
（Ｏ／Ｃ）_Ａ：ビニル重合体（Ａ）を乾燥して得られたフィルムのＸＰＳ測定から求められるＯ１ｓとＣ１ｓのピーク面積比

ここで、
（Ｏ／Ｃ）_Ｂ：アクリル系粘着性ポリマー（Ｂ）を乾燥して得られたフィルムのＸＰＳ測定から求められるＯ１ｓとＣ１ｓのピーク面積比 The peak area ratios of O1s and C1s determined by XPS measurement of the film obtained by drying each of the vinyl polymer (A) and the acrylic adhesive polymer (B) are the following equations (2) and (2), respectively. It is represented by 3).

here,
(O / C) _A : Peak area ratio of O1s to C1s obtained from XPS measurement of a film obtained by drying the vinyl polymer (A).

here,
(O / C) _B : Peak area ratio of O1s to C1s obtained from XPS measurement of a film obtained by drying an acrylic adhesive polymer (B).

さらに、上記で求めたＷ_Ａの値と下記式（５）から、アクリル系粘着性ポリマー（Ｂ）の質量分率（Ｗ_Ｂ）が算出される。

ここで、
Ｗ_Ｂ：ビニル重合体（Ａ）及びアクリル系粘着性ポリマー（Ｂ）の総量に対するアクリル系粘着性ポリマー（Ｂ）の質量分率 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 1, each element in the above formula (4) is shown below.
(O / C) _{A + B} : 0.3 (actual measurement value)
(O / C) _A : 0.3 (actual measurement value)
(O / C) _B : 0.5 (actual measurement value)
NC _-A : 5 × 90 (%) + 8 × 10 (%) = 5.3 based on the number of carbon atoms in one MMA molecule (5), the number of carbon atoms in St1 molecule (8), and the composition ratio.
NC _-B : 6 × 94 (%) + 5 × 6 (%) = 5.9 based on the number of carbon atoms in one MEA molecule (6), the number of carbon atoms in one HEA molecule (5), and the composition ratio.
M _w-A : 100 x 90 (%) + 104 x 10 (%) = 100 from the molecular weight of MMA (100), the molecular weight of St (104), and the composition ratio.
M _w-B : Based on the molecular weight of MEA (130), the molecular weight of HEA (116), and the composition ratio, 130 × 94 (%) +116 × 6 (%) = 129.
_W A = 0.8 is obtained by substituting these values into equation _{(4), (5) W} B = 0.2 is 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 50.3 ° C. was obtained.
1 / [Tg of the surface layer portion] _{(K) = W A / Tg} A + W B / Tg B (6)
here,
Tg _A : Tg (80 ° C.) of the vinyl polymer (A)
Tg _B : Tg (-31 ° C) of acrylic adhesive polymer (B)

<Durability of curved surface laminated film>
An easy-adhesion-treated PET film having a thickness of 100 μm was attached to one side of the adhesive film sample to prepare an adhesive sheet, which was then cut into a width of 20 mm and a length of 12.5 mm. This was wound around a PP columnar rod of 8 mmΦ and fixed to the columnar rod by laminating with cellophane tape. By the above procedure, the adhesive sheet is in a state of being attached over approximately 50% of the circumference of each cylindrical rod. Next, the pressure bonding treatment was performed at 50 ° C., 0.5 MPa, and 20 minutes in an autoclave while being fixed with cellophane tape. After crimping, the sample was stored at 23 ° C. and 50% RH for 1 hour, and the cellophane tape was peeled off as a sample. The sample was allowed to stand at 23 ° C. for 24 hours and 120 ° C. for 24 hours, and the presence or absence of peeling of the adhesive sheet and the peeling distance when the adhesive sheet was peeled off were measured and evaluated based on the criteria shown below. did.
〇: No peeling △: Adhesive sheet peeled distance is 1 mm or less ×: Adhesive sheet peeled distance exceeds 1 mm

<Happoshu resistance>
An easy-adhesion-treated PET film having a thickness of 100 μm was attached to one side of the adhesive film sample to prepare a laminate, and a PP plate or a polycarbonate (PC) plate was attached to the other surface to prepare a laminate. A crimping treatment was performed at 5.5 MPa for 20 minutes. Then, the laminate was loaded for 24 hours in a constant temperature and humidity chamber at 60 ° C./90%, and the appearance (presence or absence of foaming) after loading was visually confirmed and evaluated according to the following criteria.
◯: No change in appearance Δ: Area of foamed portion is 10% or less of the area of the test piece ×: Area of the foamed portion is more than 10% of the area of the test piece

Examples 2 to 6 and Comparative Examples 1 to 4
In Example 1, the types and ratios of the vinyl polymer and the acrylic adhesive polymer were changed as shown in Tables 3 and 4 to obtain a pressure-sensitive adhesive composition, and the same measurement as in Example 1 was performed. The results are shown in Tables 3 and 4.

As shown in Table 3, in each of Examples 1 to 6 using the pressure-sensitive adhesive composition disclosed in the present specification, the Tg of the surface layer portion of the pressure-sensitive adhesive layer is 40 ° C. rather than the Tg of the entire pressure-sensitive adhesive layer. As described above, it showed good peel strength (23 ° C. and 85 ° C.), and also showed good foam resistance to PP plate and PC plate. In particular, when the Tg of the surface layer portion of the pressure-sensitive adhesive layer is 60 ° C. or higher than the Tg of the entire pressure-sensitive adhesive layer and the Tg of the surface layer portion of the pressure-sensitive adhesive layer is 25 ° C. or higher, good curved surface adhesion even under high temperature conditions. It showed sex (120 ° C., 24 hours).

Further, as compared with Examples 4 to 6, in Examples 1 to 3, the structural unit derived from the (meth) acrylic acid alkoxyalkyl ester with respect to all the constituent monomers of the acrylic adhesive polymer (B) was 85 mass by mass. Since it contains% or more, good results were shown in all of peel strength, curved surface adhesiveness and foam resistance.

On the other hand, as shown in Table 4, in Comparative Examples 1 to 3 using the non-segregating pressure-sensitive adhesive composition, the Tg distribution in the pressure-sensitive adhesive layer was not observed, and the peel strength at both 23 ° C. and 85 ° C. was both. In addition to being low, the curved surface adhesiveness and foam resistance were not sufficient. Further, in Comparative Example 4, the Tg of the surface layer portion of the pressure-sensitive adhesive layer and the Tg of the entire pressure-sensitive adhesive layer are similarly low, and the Tg of the surface layer portion of the pressure-sensitive adhesive layer is only 0.8 ° C. higher than the Tg of the entire pressure-sensitive adhesive layer. Therefore, neither curved surface adhesiveness nor foam resistance could be exhibited.

Claims (10)

A decorative film comprising a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive composition containing a vinyl polymer (A) and an acrylic pressure-sensitive adhesive polymer (B) on at least one side of a base material.
The vinyl polymer (A) has a glass transition temperature (Tg) of 30 ° C. or higher and 200 ° C. or lower, and has a number average molecular weight of 500 to 10,000.
The pressure-sensitive adhesive composition contains the vinyl polymer (A) 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 further contains a cross-linking agent. Ori,
The pressure-sensitive adhesive layer obtained by cross-linking the pressure-sensitive adhesive composition with the cross-linking agent, wherein the first Tg, which is the glass transition temperature of the entire pressure-sensitive adhesive layer, is −80 ° C. or higher and 10 ° C. or lower. wherein a is a second Tg of 25 ° C. higher than the glass transition temperature calculated from the surface layer portion obtained by X-ray photoelectron spectroscopic analysis of the pressure-sensitive adhesive layer, the first higher due 60 ° C. or higher than Tg A decorative film provided with the pressure-sensitive adhesive layer for being attached to a molded body having a curved surface . The glass transition temperature of the vinyl polymer (A) is 60 ° C. or higher and 150 ° C. or lower, and the glass transition temperature of the acrylic adhesive polymer (B) is −80 ° C. or higher and −20 ° C. or lower.
The number average molecular weight of the vinyl polymer (A) is 500 or more and 7,000 or less.
The amount of the vinyl polymer (A) is 1 part by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the acrylic adhesive polymer (B).
A structural unit derived from one or more selected from the group consisting of (meth) acrylic acid alkyl esters, aliphatic ring-based vinyl monomers and aromatic vinyl compounds in the vinyl polymer (A). The decorative film according to claim 1. The number average molecular weight of the vinyl polymer (A) is 1,000 or more and 5,000 or less.
The decorative film according to claim 1 or 2, wherein the acrylic adhesive polymer (B) has a weight average molecular weight of 100,000 or more and 1,000,000 or less . The pressure-sensitive adhesive layer is formed by applying a pressure-sensitive adhesive sheet (width 20 mm, length 12.5 mm) having the pressure-sensitive adhesive layer having a thickness of 50 μm on a 100 μm-thick polyethylene terephthalate film substrate with respect to a polypropylene columnar rod having a diameter of 8 mm. After fixing and crimping in an autoclave at 50 ° C. for 0.5 MPa for 20 minutes, the test piece obtained by storing at 23 ° C. and 50% RH for 1 hour was allowed to stand at 120 ° C. for 24 hours. The decorative film according to any one of claims 1 to 3, wherein the peeled distance is 1 mm or less. The acrylic adhesive polymer (B) according to any one of claims 1 to 4, wherein the acrylic adhesive polymer (B) contains 85% by mass or more of a structural unit derived from (meth) acrylic acid alkoxyalkyl ester with respect to all the constituent monomers. The decorative film described. The decorative film according to any one of claims 1 to 5 , wherein the haze value of the pressure-sensitive adhesive layer is 2.0 or less. Claims 1 to 25, wherein the pressure-sensitive adhesive layer of the pressure-sensitive adhesive composition having a thickness of 50 μm on a 100 μm-thick polyethylene terephthalate film substrate has a peel strength of 3.0 N / 25 mm or more with respect to a polypropylene plate at 85 ° C. The decorative film according to any one of 6 . A pressure-sensitive adhesive composition for a decorative film, which comprises a pressure-sensitive adhesive layer on at least one side of a base material and decorates a molded product having a curved surface.
Contains vinyl polymer (A), acrylic adhesive polymer (B) and cross-linking agent
The vinyl polymer (A) has a glass transition temperature (Tg) of 30 ° C. or higher and 200 ° C. or lower, and has a number average molecular weight of 500 to 10,000.
The vinyl polymer (A) 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).
The pressure-sensitive adhesive layer obtained by cross-linking the pressure-sensitive adhesive composition with the cross-linking agent has a first Tg of −80 ° C. or higher and 10 ° C. or lower, which is the glass transition temperature of the entire pressure-sensitive adhesive layer, and the pressure-sensitive adhesive. The second Tg, which is the glass transition temperature calculated from the surface layer portion of the agent layer obtained by X-ray photoelectron spectroscopic analysis, is 25 ° C. or higher, and is 60 ° C. or higher higher than the first Tg. Adhesive composition that has been. A decorative molded product obtained by attaching the decorative film according to any one of claims 1 to 7 to at least a part of the curved surface of the molded product. The decorative molded product according to claim 9, wherein the molded product is made of plastic.