KR20210144720A - Pressure-sensitive adhesive composition, pressure-sensitive adhesive layer, and pressure-sensitive adhesive sheet - Google Patents

Abstract

The present invention is a pressure-sensitive adhesive composition containing a base polymer and at least one type of oligomer, wherein the oligomer is obtained by polymerizing a monomer composition containing at least a vinyl monomer having at least one type of dye structure in a side chain. It relates to a pressure-sensitive adhesive composition.

Description

Pressure-sensitive adhesive composition, pressure-sensitive adhesive layer, and pressure-sensitive adhesive sheet

The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive layer, and a pressure-sensitive adhesive sheet.

Conventionally, since it is easy to grasp|ascertain a position in an operation|work, such as a processing process and pasting, a transparent tape has been used often. On the other hand, for purposes, such as a change of design, designability, and visibility improvement, the colored adhesive tape is also used.

Pigments or dyes are often used to color the adhesive tape. For example, in Patent Document 1, an adhesive composition containing an acrylic polymer, a phenol resin, an epoxy resin, and a colorant, and containing 10 parts by weight or less of a colorant with respect to 100 parts by weight of the acrylic polymer. It is disclosed that a dye is preferably used.

Japanese Laid-Open Patent Publication No. 2015-013946

However, when coloring an adhesive tape using a pigment or dye, there exists a possibility that an aggregate may generate|occur|produce in an adhesive composition, and when a dispersing agent is not used, favorable dispersibility was not obtained.

Moreover, after a dye component bleeds out from an adhesive composition and peels an adhesive tape, there also existed a problem with which a pigment|dye component will remain|survive in a to-be-adhered body.

In addition, depending on the type of pigment or dye, it may cause deterioration of adhesive properties. In addition, there are cases where a resin having a high acid value is used to improve the dispersibility of the pigment, and in that case, other problems such as corrosion of metal adherends such as iron, stainless steel, and ITO may occur.

Therefore, the present invention provides a pressure-sensitive adhesive composition that has good adhesion in a colored pressure-sensitive adhesive composition, has good dispersibility even when a high acid value resin or dispersant is not used, and that bleed-out of the dye component does not occur. make it one task.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the present inventors repeated earnest examination. As a result, by using the oligomer obtained from the vinyl monomer which has an at least 1 sort(s) of pigment|dye structure for a side chain, it discovered that the said subject was solvable, and came to complete invention.

One embodiment of the present invention is a pressure-sensitive adhesive composition containing a base polymer and at least one type of oligomer, wherein the oligomer is obtained by polymerizing a monomer composition containing at least a vinyl monomer having at least one type of dye structure in a side chain. It relates to an oligomer, characterized in that the pressure-sensitive adhesive composition.

In one embodiment of the present invention, in the pressure-sensitive adhesive composition, the base polymer is preferably a (meth)acrylic polymer.

In one embodiment of the present invention, in the pressure-sensitive adhesive composition, it is preferable that the oligomer is a (meth)acrylic oligomer.

In one Embodiment of this invention, the homopolymer of the (meth)acrylic-type monomer in which the said (meth)acrylic-type oligomer has at least 1 sort(s) of dye structure in a side chain may be sufficient as an adhesive composition.

In one Embodiment of this invention, the copolymer of the (meth)acrylic-type monomer and (meth)acrylic-acid alkylester in which the said (meth)acrylic-type oligomer has at least 1 type of dye structure in a side chain may be sufficient as an adhesive composition.

In one embodiment of the present invention, the pressure-sensitive adhesive composition preferably has a weight average molecular weight of the oligomer of 1,000 to 50,000.

One embodiment of the present invention relates to a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition.

One Embodiment of this invention relates to the adhesive sheet provided with the said adhesive layer.

In one embodiment of the present invention, the pressure-sensitive adhesive sheet may include the pressure-sensitive adhesive layer on a transparent film.

According to one embodiment of the present invention, it is possible to provide a colored pressure-sensitive adhesive composition having good adhesion, good dispersibility even when a high acid value resin or dispersing agent is not used, and bleed-out of the dye component does not occur. have.

BRIEF DESCRIPTION OF THE DRAWINGS It is an example of the schematic sectional drawing of the adhesive layer which concerns on embodiment of this invention.
It is an example of the schematic sectional drawing of the adhesive sheet which concerns on embodiment of this invention.
3 : is an example of the schematic sectional drawing of the adhesive sheet which concerns on embodiment of this invention.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail. In addition, this invention is not limited to embodiment demonstrated below.

In this specification, "A to B" which shows a range means "A or more and B or less." In addition, in this specification, "mass %" is made into the same meaning as "weight%", and "mass part" is handled with the same meaning as "weight part".

[Adhesive composition]

The adhesive composition which concerns on one Embodiment of this invention is a base polymer and the adhesive composition containing at least 1 type of oligomer, Comprising: The said oligomer is a monomer containing at least the vinyl monomer which has at least 1 type of dye structure in a side chain. It is characterized in that it is obtained by polymerizing the composition.

Since the said adhesive composition uses the oligomer obtained by superposing|polymerizing the vinyl monomer which has a dye structure in a side chain as a pigment|dye, dispersibility is favorable even if it does not use resin or a dispersing agent of a high acid value, and also bleed-out of a pigment component This does not happen.

Hereinafter, each component contained in the said adhesive composition is demonstrated in detail.

<Base Polymer>

In the pressure-sensitive adhesive composition according to the embodiment of the present invention, the base polymer constituting the pressure-sensitive adhesive composition is not particularly limited, and a known polymer used for the pressure-sensitive adhesive can be used.

For example, a (meth)acrylic-type polymer, a rubber-type polymer, a vinyl alkyl ether-type polymer, a silicone-type polymer, a polyester-type polymer, a polyamide-type polymer, a urethane-type polymer, a fluorine-type polymer, an epoxy-type polymer, etc. are mentioned. Especially, from a viewpoint that coloring by a pigment|dye becomes clear, the (meth)acrylic-type polymer with high transparency is more preferable. In addition, these polymers may be used individually by 1 type, and may be used in combination of 2 or more type.

In addition, a (meth)acrylic-type polymer means an acryl-type polymer and/or a methacryl-type polymer, and (meth) of this invention has all the same meaning.

Hereinafter, in the adhesive composition which concerns on one Embodiment of this invention, although the aspect containing a (meth)acrylic-type polymer as a base polymer is mainly demonstrated, this invention is not limited to this aspect.

The pressure-sensitive adhesive composition according to one embodiment of the present invention may contain a (meth)acrylic polymer as a base polymer. Typically, the pressure-sensitive adhesive composition may be a (meth)acrylic pressure-sensitive adhesive composition containing a (meth)acrylic polymer as a main component. A (meth)acrylic adhesive composition is excellent in transparency.

As the pressure-sensitive adhesive composition according to the embodiment of the present invention, for example, a ratio of 40 mass% or more of (meth)acrylic acid alkylester having a linear or branched alkyl group having 1 to 20 carbon atoms at the ester terminal. It is preferable to contain as a base polymer the (meth)acrylic-type polymer comprised from the monomer component containing Hereinafter, the (meth)acrylic acid alkylester having an alkyl group having X or more and Y or less alkyl group at the ester terminal is sometimes referred to as _{"(meth)acrylic acid C XY alkyl ester".}

_{Since it is easy to balance the characteristics, the ratio of (meth)acrylic acid C 1-20} alkylester in the whole monomer component of the (meth)acrylic polymer according to one aspect is suitably more than 50 mass%, for example, 55 Mass % or more may be sufficient, 60 mass % or more may be sufficient, and 70 mass % or more may be sufficient.

For the same reason, the ratio of the (meth)acrylic acid C _1-20 alkylester in the monomer component may be, for example, 99.9 mass% or less, 99.5 mass% or less, or 99 mass% or less.

_{The ratio of C 1-20} (meth)acrylic acid alkyl ester in the whole monomer component of the (meth)acrylic polymer according to another aspect may be, for example, 98 mass% or less, and 95 mass% from the viewpoint of improving the cohesiveness of the pressure-sensitive adhesive layer % or less may be sufficient, 85 mass % or less (for example, less than 80 mass %) may be sufficient, 70 mass % or less may be sufficient, and 60 mass % or less may be sufficient.

Non-limiting examples of (meth)acrylic acid C _1-20 alkyl ester include (meth) methyl acrylate, (meth) ethyl acrylate, (meth) acrylic acid propyl, (meth) acrylic acid isopropyl, (meth) acrylic acid n- Butyl, (meth) acrylate isobutyl, (meth) acrylate s-butyl, (meth) acrylate t-butyl, (meth) acrylate pentyl, (meth) acrylate isopentyl, (meth) acrylate hexyl, (meth) acrylate heptyl, (meth) acrylate octyl, (meth) acrylic acid 2-ethylhexyl, (meth) acrylate isooctyl, (meth) acrylate nonyl, (meth) acrylate isononyl, (meth) acrylate decyl, (meth) acrylate isodecyl, ( Undecyl acrylate, (meth) acrylate dodecyl, (meth) acrylic acid tridecyl, (meth) acrylic acid tetradecyl, (meth) acrylic acid pentadecyl, (meth) acrylic acid hexadecyl, (meth) acrylic acid heptadecyl, (meth) acrylate ) stearyl acrylate, isostearyl (meth) acrylate, nonadecyl (meth) acrylate, and eicosyl (meth) acrylate.

Among them, the at least (meth) acrylic acid is preferred to use a C _4-20 alkyl ester, and it is more preferable to use at least a (meth) acrylic acid C _4-18 alkyl ester. For example, as the monomer component, it is preferable to contain one or both of n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA), and a (meth)acrylic pressure-sensitive adhesive containing at least BA is particularly preferable. .

Other examples of (meth)acrylic acid C _4-20 alkyl esters that can be preferably used include isononyl acrylate, n-butyl methacrylate (BMA), 2-ethylhexyl methacrylate (2EHMA), and isoste acrylate. aryl (iSTA); and the like.

In some embodiments, the monomer component constituting the (meth)acrylic polymer may contain (meth)acrylic acid C _4-18 alkylester in a proportion of 40 mass% or more. The ratio of the (meth)acrylic acid C _4-18 alkylester in the monomer component may be, for example, 50 mass% or more, 60 mass% or more, or 65 mass% or more. A monomer component containing a _{(meth)acrylic acid C 6-18} alkyl ester in a ratio greater than or equal to the lower limit of any of the above may be used.

Moreover, from a viewpoint of improving the cohesiveness of an adhesive layer _{, it is suitable that the ratio of the (meth)acrylic acid C4-18} alkylester occupied in a monomer component shall be normally 99.5 mass % or less, 95 mass % or less may be sufficient, and 85 mass % % or less may be sufficient and 75 mass % or less may be sufficient. The monomer component containing the _{(meth)acrylic acid C6-18} alkylester in the ratio below any upper limit of the above-mentioned may be sufficient.

The monomer component constituting the (meth)acrylic polymer may contain, if necessary, other monomers copolymerizable with the (meth)acrylic acid alkylester (copolymerizable monomer) together with the (meth)acrylic acid alkyl ester.

As the copolymerizable monomer, a monomer having a polar group (for example, a carboxyl group, a hydroxyl group, and a nitrogen atom-containing ring, etc.) or a monomer having a relatively high glass transition temperature of the homopolymer (for example, 10° C. or higher) is preferably used. can

A monomer having a polar group may be helpful in order to introduce a crosslinking point to the (meth)acrylic polymer or to increase the cohesive force of the pressure-sensitive adhesive. A copolymerizable monomer can be used individually by 1 type or in combination of 2 or more type.

Non-limiting examples of the copolymerizable monomer include the following.

Carboxyl group-containing monomers: For example, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, and the like.

Acid anhydride group-containing monomers: for example, maleic anhydride, itaconic anhydride, and the like.

Hydroxyl group-containing monomer: For example, (meth)acrylic acid 2-hydroxyethyl, (meth)acrylic acid 2-hydroxypropyl, (meth)acrylic acid 2-hydroxybutyl, (meth)acrylic acid 3-hydroxypropyl, (meth)acrylic acid ) acrylic acid 4-hydroxybutyl, (meth)acrylic acid 6-hydroxyhexyl, (meth)acrylic acid 8-hydroxyoctyl, (meth)acrylic acid 10-hydroxydecyl, (meth)acrylic acid 12-hydroxylauryl, and (meth)acrylic acid hydroxyalkyl, such as (4-hydroxymethylcyclohexyl)methyl (meth)acrylate.

Monomers containing a sulfonic acid group or a phosphoric acid group: For example, styrenesulfonic acid, allylsulfonic acid, sodium vinylsulfonate, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, sulfopropyl (meth) acrylates, (meth)acryloyloxynaphthalenesulfonic acid, and 2-hydroxyethylacryloylphosphate, and the like.

Epoxy group-containing monomers: For example, epoxy group-containing acrylates such as (meth)acrylic acid glycidyl and (meth)acrylic acid-2-ethylglycidyl ether, allyl glycidyl ether, and (meth)acrylic acid glycidyl ether etc.

Cyano group-containing monomers: for example, acrylonitrile, methacrylonitrile, and the like.

Isocyanate group-containing monomer: For example, 2-isocyanate ethyl (meth)acrylate etc.

Amide group-containing monomer: For example, (meth)acrylamide; N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-dipropyl (meth)acrylamide, N,N-diisopropyl (meth)acrylamide, N, N,N-dialkyl (meth)acrylamide, such as N-di(n-butyl)(meth)acrylamide and N,N-di(t-butyl)(meth)acrylamide; N-alkyl (meth)acrylamide, such as N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-butyl (meth)acrylamide, and N-n-butyl (meth)acrylamide; N-vinyl carboxylic acid amides, such as N-vinyl acetamide; Monomers having a hydroxyl group and an amide group, for example, N-(2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)acrylamide, N-(1-hydroxypropyl) (meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide, N-(2-hydroxybutyl)(meth)acrylamide, N-(3-hydroxybutyl)(meth)acrylamide , N-hydroxyalkyl (meth)acrylamide, such as N-(4-hydroxybutyl) (meth)acrylamide; Monomers having an alkoxy group and an amide group, for example, N-alkoxyalkyl (N- methoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, meth)acrylamide; In addition, N,N-dimethylaminopropyl (meth)acrylamide, N-(meth)acryloylmorpholine, and the like.

Amino group-containing monomers: for example, aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate.

Monomers having an epoxy group: For example, glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, and allyl glycidyl ether.

Monomers having a nitrogen atom-containing ring: for example, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinyl Piperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-(meth)acryloyl-2-pyrrolidone, N-(meth)acryloylpiperi Dean, N-(meth)acryloylpyrrolidine, N-vinylmorpholine, N-vinyl-3-morpholinone, N-vinyl-2-caprolactam, N-vinyl-1,3-oxazine-2 -one, N-vinyl-3,5-morpholinedione, N-vinylpyrazole, N-vinylisoxazole, N-vinylthiazole, N-vinylisothiazole, and N-vinylpyridazine (e.g. , lactams such as N-vinyl-2-caprolactam) and the like.

Monomers having a succinimide skeleton: for example, N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, and N-(meth) acryloyl-8-oxyhexamethylenesuccinimide and the like.

Maleimides: For example, N-cyclohexyl maleimide, N-isopropyl maleimide, N-lauryl maleimide, N-phenyl maleimide, and the like.

Itaconimides: For example, N-methylitaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itacon mide, N-cyclohexylitaconimide, and N-laurylitaconimide, and the like.

Aminoalkyl (meth)acrylate: For example, aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, and (meth)acrylic acid t -Butylaminoethyl, etc.

Alkoxy group-containing monomers: For example, (meth)acrylic acid 2-methoxyethyl, (meth)acrylic acid 3-methoxypropyl, (meth)acrylic acid 2-ethoxyethyl, (meth)acrylic acid propoxyethyl, (meth) (meth)acrylate alkoxyalkyl (alkoxyalkyl (meth)acrylate), such as butoxyethyl acrylate and ethoxypropyl (meth)acrylate; (meth)acrylic acid alkoxyalkylene glycols such as (meth)acrylic acid methoxyethylene glycol, (meth)acrylic acid methoxypolyethylene glycol, and (meth)acrylic acid methoxypolypropylene glycol (for example, alkoxypolyalkylene glycol (meth) acrylates).

Alkoxysilyl group-containing monomer: for example, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3- Alkoxysilyl group-containing vinyl compounds, such as (meth)acrylates containing alkoxysilyl groups, such as (meth)acryloxypropylmethyldiethoxysilane, vinyl trimethoxysilane, and vinyl triethoxysilane, etc.

Vinyl esters: For example, vinyl acetate, vinyl propionate, and the like.

Vinyl ethers: For example, vinyl alkyl ethers such as methyl vinyl ether and ethyl vinyl ether.

Aromatic vinyl compounds: for example, styrene, α-methylstyrene, vinyltoluene, and the like.

Olefins: For example, ethylene, butadiene, isoprene, isobutylene, and the like.

(meth)acrylic acid ester having an alicyclic hydrocarbon group: for example, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and (meth)acrylates containing an alicyclic hydrocarbon group such as adamantyl (meth)acrylate.

(meth)acrylic acid ester having an aromatic hydrocarbon group: For example, (meth)acrylate containing an aromatic hydrocarbon group such as phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, and benzyl (meth)acrylate.

In addition, heterocyclic (meth)acrylates such as (meth)acrylic acid tetrahydrofurfuryl, halogen atom-containing (meth)acrylates such as vinyl chloride and fluorine atom-containing (meth)acrylates, and silicone (meth)acrylates Silicon atom-containing (meth)acrylates, such as (meth)acrylic acid ester obtained from terpene compound derivative alcohol, etc.

When using such a copolymerizable monomer, although the usage-amount is not specifically limited, Usually, it is suitable to set it as 0.01 mass % or more of the whole monomer component. From the viewpoint of better exhibiting the effect of using the copolymerizable monomer, the amount of the copolymerizable monomer used may be 0.1 mass% or more of the whole monomer component, or may be 0.5 mass% or more.

Moreover, from a viewpoint of making it easy to balance an adhesive characteristic, it is suitable that the usage-amount of a copolymerizable monomer shall normally be 50 mass % or less of the whole monomer component, and it is preferable to set it as 40 mass % or less.

In some embodiments, the monomer component constituting the (meth)acrylic polymer may contain a monomer having a nitrogen atom. Thereby, the cohesive force of an adhesive can be raised and the peeling force after time can improve preferably.

A suitable example of the monomer having a nitrogen atom includes a monomer having a nitrogen atom-containing ring. As the monomer having a nitrogen atom-containing ring, those exemplified above can be used, and examples thereof include N-vinyl cyclic amides represented by the following general formula (1).

[Formula 1]

From here, the general formula ^(1), R 1 is a divalent organic group, specifically, - (CH _{2) n} - is a. n is an integer of 2 to 7 (preferably 2, 3 or 4). Among them, N-vinyl-2-pyrrolidone can be preferably employed. As another suitable example of the monomer which has a nitrogen atom, (meth)acrylamide is mentioned.

The amount of the monomer having a nitrogen atom (preferably a monomer having a nitrogen atom-containing ring) to be used is not particularly limited, and for example, 1% by mass or more, 3% by mass or more, 5% by mass or more, or 7% by mass of the entire monomer component. You can do more than that.

In one aspect, the usage-amount of the monomer which has a nitrogen atom may be 10 mass % or more of the whole monomer component, 15 mass % or more may be sufficient, and 20 mass % or more may be sufficient as it.

Moreover, it is suitable that the usage-amount of the monomer which has a nitrogen atom shall be 40 mass % or less of the whole monomer component, even if it is good also as 35 mass % or less, it is good also as 30 mass % or less, even if it is 25 mass % or less. do.

In another aspect, the usage-amount of the monomer which has a nitrogen atom is good also as 20 mass % or less of the whole monomer component, and good also as 15 mass % or less.

In some embodiments, the monomer component constituting the (meth)acrylic polymer may contain a hydroxyl group-containing monomer. By use of the hydroxyl group-containing monomer, the cohesive force of the pressure-sensitive adhesive and the degree of crosslinking (eg, crosslinking with an isocyanate crosslinking agent) can be suitably adjusted.

In the case of using a hydroxyl-containing monomer, the usage-amount in particular is not restrict|limited, For example, 0.01 mass % or more of the whole monomer component may be sufficient, 0.1 mass % or more may be sufficient, 0.5 mass % or more may be sufficient, 1 mass % or more, 5 mass % or more or 10 mass % or more may be sufficient.

Moreover, from a viewpoint of suppressing the water absorption of an adhesive layer, in some aspects, it is suitable that the usage-amount of a hydroxyl-containing monomer shall be 40 mass % or less of the whole monomer component, for example, It is good also as 30 mass % or less, 25 It is good also as mass % or less, and is good also as 20 mass % or less.

In another aspect, the usage-amount of a hydroxyl-containing monomer is good also as 15 mass % or less of the whole monomer component, good also as 10 mass % or less, and good also as 5 mass % or less.

In the pressure-sensitive adhesive composition according to an embodiment of the present invention, the monomer component of the (meth)acrylic polymer may include the alkoxyalkyl (meth)acrylate or alkoxypolyalkylene glycol (meth)acrylate exemplified above, You don't have to include it.

In one aspect of the technology related to this aspect, the ratio of alkoxyalkyl (meth)acrylate in the monomer component of the (meth)acrylic polymer is less than 20% by mass, and the ratio of alkoxypolyalkylene glycol (meth)acrylate is 20 It is less than mass %. Thereby, the adhesive layer is easy to form a sheet|seat without problems, such as gelatinization. By adopting the above monomer composition, the solid content concentration of the monomer mixture is maintained in a predetermined range to obtain a desired high molecular weight (for example, a weight average molecular weight (Mw) ^{greater than 30 × 10 4} , typically Mw 40 × 10 ⁴ or greater). can be polymerized.

The proportion of the alkoxyalkyl (meth)acrylate in the monomer component is preferably less than 10 mass%, more preferably less than 3 mass%, still more preferably less than 1 mass%, and in a particularly preferred aspect, The monomer component does not contain an alkoxyalkyl (meth)acrylate substantially (content 0-0.3 mass %).

Similarly, the proportion of the alkoxypolyalkylene glycol (meth)acrylate in the monomer component is preferably less than 10 mass%, more preferably less than 3 mass%, still more preferably less than 1 mass%, particularly preferably In one aspect, the said monomer component does not contain alkoxy polyalkylene glycol (meth)acrylate substantially (content 0-0.3 mass %).

In addition, in the monomer component of the (meth)acrylic polymer according to one preferred aspect, the total ratio of the alkoxyalkyl (meth)acrylate and the alkoxypolyalkylene glycol (meth)acrylate is less than 20% by mass from the viewpoint of suppressing gelation. Limited.

The total ratio of the alkoxyalkyl (meth)acrylate and the alkoxypolyalkylene glycol (meth)acrylate is more preferably less than 10 mass%, still more preferably less than 3 mass%, particularly preferably less than 1 mass%. and, in one embodiment, the monomer component does not substantially contain alkoxyalkyl (meth)acrylate and alkoxypolyalkylene glycol (meth)acrylate (content 0 to 0.3 mass%).

Similarly, the monomer component of the (meth)acrylic polymer according to this aspect may or may not contain an alkoxy group-containing monomer in a proportion of less than 20 mass%. The amount of the alkoxy group-containing monomer in the monomer component is preferably less than 10 mass%, more preferably less than 3 mass%, still more preferably less than 1 mass%, and in a particularly preferred embodiment, the monomer component is alkoxy It does not contain a group-containing monomer substantially (content 0-0.3 mass %).

In some embodiments, the ratio of the carboxyl group-containing monomer in the monomer component of the (meth)acrylic polymer may be, for example, 2 mass% or less, 1 mass% or less, and 0.5 mass% or less (for example, 0.1 mass%) less) may be sufficient. As the monomer component of the (meth)acrylic polymer, it is not necessary to substantially use a carboxyl group-containing monomer. Here, not using a carboxyl group-containing monomer substantially means not using a carboxyl group-containing monomer at least intentionally.

A (meth)acrylic polymer having such a composition tends to be highly reliable in water resistance, and may have metal corrosion-preventing properties for an adherend containing a metal.

Moreover, in one preferable aspect, the ratio of a hydrophilic monomer is restrict|limited in the monomer component of a (meth)acrylic-type polymer. Here, the "hydrophilic monomer" in the present specification refers to a carboxyl group-containing monomer, an acid anhydride group-containing monomer, a hydroxyl group-containing monomer, and a nitrogen atom-containing monomer (typically, an amide group-containing monomer such as (meth)acrylamide, and a monomer having a nitrogen atom-containing ring such as N-vinyl-2-pyrrolidone) and an alkoxy group-containing monomer (typically, alkoxyalkyl (meth)acrylate and alkoxypolyalkylene glycol (meth)acrylate) do it by saying

In this aspect, it is preferable that the ratio of the said hydrophilic monomer in the monomer component of a (meth)acrylic-type polymer is 32 mass % or less, for example, 30 mass % or less may be sufficient, and 28 mass % or less may be sufficient.

Although it does not specifically limit, The ratio of the said hydrophilic monomer in the monomer component of a (meth)acrylic-type polymer may be 1 mass % or more, 10 mass % or more may be sufficient, and 20 mass % or more may be sufficient as it.

In some embodiments, the monomer component constituting the (meth)acrylic polymer may contain an alicyclic hydrocarbon group-containing (meth)acrylate. Thereby, the cohesive force of an adhesive can be raised, and the peeling force after time can be improved.

As the alicyclic hydrocarbon group-containing (meth)acrylate, those exemplified above can be used, and for example, cyclohexyl acrylate or isobornyl acrylate can be preferably employed. The usage-amount in particular in the case of using an alicyclic hydrocarbon group containing (meth)acrylate is not restrict|limited, For example, it can be 1 mass % or more, 3 mass % or more, or 5 mass % or more of the whole monomer component.

In one aspect, the usage-amount of the alicyclic hydrocarbon group containing (meth)acrylate may be 10 mass % or more of the whole monomer component, and 15 mass % or more may be sufficient as it.

The upper limit of the usage-amount of an alicyclic hydrocarbon group containing (meth)acrylate is 40 mass % or less suitably, for example, may be 30 mass % or less, and may be 25 mass % or less (for example, 15 mass % or less, furthermore may be 10 mass% or less).

The composition of the monomer component constituting the (meth)acrylic polymer may be set such that the glass transition temperature Tg obtained by Fox's formula based on the composition of the monomer component is -75°C or more and 10°C or less.

In some embodiments, the Tg is preferably 0°C or less, preferably -10°C or less, and may be -20°C or less or -30°C or less from the viewpoints of cohesiveness and impact resistance.

Further, the Tg may be, for example, -60°C or higher, -50°C or higher, -45°C or higher, or -40°C or higher.

Here, the formula of Fox is a relational expression between Tg of the copolymer and the glass transition temperature Tgi of a homopolymer obtained by homopolymerizing each of the monomers constituting the copolymer, as shown below.

1/Tg = Σ(Wi/Tgi)

In addition, in the above Fox formula, Tg is the glass transition temperature of the copolymer (unit: K), Wi is the weight fraction of the monomer i in the copolymer (copolymerization ratio based on weight), Tgi is the homo of the monomer i The glass transition temperature (unit: K) of the polymer is shown.

As the glass transition temperature of the homopolymer used for the calculation of Tg, the value described in known materials is used. For example, for the monomers listed below, the values below are used as the glass transition temperature of the homopolymer of the monomer.

2-ethylhexyl acrylate -70 ℃

n-Butyl acrylate -55 ℃

Isostearyl acrylate -18 ℃

Methyl methacrylate 105 °C

Methyl acrylate 8 °C

Cyclohexyl acrylate 15 °C

N-vinyl-2-pyrrolidone 54 °C

2-hydroxyethyl acrylate -15 °C

4-hydroxybutyl acrylate -40 ℃

Dicyclofentanyl methacrylate 175 °C

Isobornyl acrylate 94 °C

Acrylic acid 106 ℃

methacrylic acid 228 ℃

For glass transition temperatures of homopolymers of monomers other than those exemplified above, the numerical values described in "Polymer Handbook" (3rd ed., John Wiley & Sons, Inc., 1989) shall be used. When multiple types of values are described in this document, the highest value is adopted.

For monomers for which the glass transition temperature of the homopolymer is not described in the Polymer Handbook, a value obtained by the following measurement method is used (see Japanese Patent Application Laid-Open No. 2007-51271).

Specifically, 100 parts by mass of a monomer, 0.2 parts by mass of azobisisobutyronitrile and 200 parts by mass of ethyl acetate as a polymerization solvent were introduced into a reactor equipped with a thermometer, a stirrer, a nitrogen introduction pipe and a reflux cooling pipe, and nitrogen gas was introduced into the reactor. Agitate for 1 hour while circulating. After removing oxygen in a polymerization system in this way, it heats up at 63 degreeC and makes it react for 10 hours. Then, it cools to room temperature, and obtains the homopolymer solution with a solid content concentration of 33 mass %. Next, this homopolymer solution is cast-coated on a release liner and dried to prepare a test sample (sheet-shaped homopolymer) having a thickness of about 2 mm. This test sample was punched out in the shape of a disk having a diameter of 7.9 mm, sandwiched between parallel plates, and subjected to shear deformation at a frequency of 1 Hz using a viscoelasticity tester (ARES, manufactured by TA Instruments) in the temperature range - The viscoelasticity is measured by shear mode at 70-150 degreeC and the temperature increase rate of 5 degreeC/min, and let the peak top temperature of tan-delta be Tg of a homopolymer.

Although the (meth)acrylic-type polymer which concerns on this aspect is not specifically limited, It is preferable that ^{SP value is 23.0 (MJ/cm<3>) 1/2 or less.} The SP value is more preferably 21.0 (MJ/cm 3 ) ^1/2 or less (eg, 20.0 (MJ/cm 3 ) ^1/2 or less).

The lower limit of the SP value is not particularly limited, for example, 10.0 (MJ/cm 3 ) ^1/2 or more, and preferably 15.0 (MJ/cm 3 ) ^1/2 or more, preferably 18.0 (MJ/cm 3 ) ¹ more than ^/2.

In addition, the SP value of the (meth)acrylic polymer is calculated by Fedors' method [refer to "Polymer Engineering & Science (POLYMER ENG. & SCI.)", Vol. 14, No. 2 (1974), pages 148 to 154) That is, the expression:

SP value δ = (ΣΔe/ΣΔv) ^1/2

(In the formula, Δe is the evaporation energy Δe of each atom or group at 25°C, and Δv is the molar volume of each atom or group at the same temperature.); can be calculated accordingly. The (meth)acrylic polymer having the SP value can be obtained by appropriately determining the monomer composition based on the technical common knowledge of those skilled in the art.

The said adhesive composition contains the monomer component of the above-mentioned composition in the form of a polymer, an unpolymer (namely, the form in which a polymerizable functional group is unreacted), or a mixture thereof.

The pressure-sensitive adhesive composition is a water-dispersible pressure-sensitive adhesive composition in which the pressure-sensitive adhesive (adhesive component) is dispersed in water; It may be in various forms, such as an active energy ray-curable adhesive composition prepared to form, and a hot-melt-type adhesive composition which is coated in a heat-melted state and forms an adhesive when it cools to room temperature vicinity.

The pressure-sensitive adhesive composition according to one preferred aspect is a solvent-type pressure-sensitive adhesive composition or a non-solvent-type pressure-sensitive adhesive composition. An active energy ray-curable adhesive composition and a hot-melt type adhesive composition are contained in a non-solvent type adhesive composition.

In superposition|polymerization, a well-known or customary thermal-polymerization initiator or a photoinitiator can be used according to a polymerization method, a polymerization aspect, etc. Such a polymerization initiator can be used individually by 1 type or in combination of 2 or more type suitably.

It does not specifically limit as a thermal-polymerization initiator. For example, an azo-based polymerization initiator, a peroxide-based initiator, a redox-based initiator obtained by combining a peroxide and a reducing agent, and a substituted ethane-based initiator can be used.

More specifically, for example, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2-methylpropionamidine) disulfate, 2,2'-azobis(2) -amidino propane) dihydrochloride, 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (N, azo initiators such as N'-dimethylene isobutylamidine) and 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate; For example, Persulfates, such as a potassium persulfate and an ammonium persulfate; peroxide-based initiators such as benzoyl peroxide, t-butyl hydroperoxide, and hydrogen peroxide; For example, Substituted ethane-type initiators, such as a phenyl-substituted ethane; For example, redox initiators, such as a combination of a persulfate and sodium hydrogensulfite, and a combination of a peroxide and sodium ascorbate; etc. are illustrated, but it is not limited to these. Further, the thermal polymerization can be preferably carried out at a temperature of, for example, 20 to 100°C (typically 40 to 80°C).

It does not specifically limit as a photoinitiator. For example, ketal-based photopolymerization initiator, acetophenone-based photopolymerization initiator, benzoin ether-based photopolymerization initiator, acylphosphine oxide-based photopolymerization initiator, α-ketol-based photopolymerization initiator, aromatic sulfonyl chloride-based photopolymerization initiator, photoactive oxime-based photopolymerization initiator, A benzoin-based photopolymerization initiator, a benzyl-based photopolymerization initiator, a benzophenone-based photopolymerization initiator, and a thioxanthone-based photopolymerization initiator may be used.

The usage-amount of such a thermal-polymerization initiator or a photoinitiator can be made into the normal usage-amount according to the polymerization method, polymerization aspect, etc., and is not specifically limited. For example, 0.001-5 mass parts (typically 0.01-2 mass parts, for example, 0.01-1 mass part) of a polymerization initiator can be used with respect to 100 mass parts of monomers to be superposed|polymerized.

For the polymerization, if necessary, various conventionally known chain transfer agents (which may also be regarded as molecular weight regulators or polymerization degree regulators) can be used.

As the chain transfer agent, mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan, thioglycolic acid, and α-thioglycerol can be used. Alternatively, a chain transfer agent not containing a sulfur atom (non-sulfur chain transfer agent) may be used.

Specific examples of the non-sulfur chain transfer agent include anilines such as N,N-dimethylaniline and N,N-diethylaniline; terpenoids such as α-pinene and terpinolene; styrenes such as α-methylstyrene and α-methylstyrene dimer; compounds having a benzylidenyl group such as dibenzylideneacetone, cinnamyl alcohol, and cinnamylaldehyde; hydroquinones such as hydroquinone and naphthohydroquinone; quinones such as benzoquinone and naphthoquinone; olefins such as 2,3-dimethyl-2-butene and 1,5-cyclooctadiene; alcohols such as phenol, benzyl alcohol, and allyl alcohol; benzyl hydrogens such as diphenylbenzene and triphenylbenzene; and the like.

A chain transfer agent can be used individually by 1 type or in combination of 2 or more type.

When using a chain transfer agent, the usage-amount can be made into 0.01-1 mass part with respect to 100 mass parts of monomer components, for example. The technique related to this aspect can be implemented preferably even if it is an aspect which does not use a chain transfer agent.

The molecular weight of the (meth)acrylic polymer obtained by appropriately employing the various polymerization methods described above is not particularly limited, and may be set within an appropriate range according to required performance. The weight average molecular weight (Mw) of the (meth)acrylic polymer is usually 10 × 10 ⁴ or more (for example, 20 × 10 ⁴ or more), and from the viewpoint of making a well-balanced cohesive force and adhesive strength, it exceeds ^{30 × 10 4} It is appropriate to do

^{The (meth)acrylic polymer according to one aspect is preferably 40 × 10 4} or more (typically 50 × 10 ⁴ or more, for example, 55 × 10 ⁴ or more) from the viewpoint of obtaining good adhesion reliability even in a high-temperature environment. has Mw of According to one preferred aspect of the technology related to this aspect, since gelation can be suppressed by the design of the monomer composition, a high molecular weight substance within the above range can be obtained with good productivity by setting an appropriate solid content concentration.

The upper limit of Mw of the (meth)acrylic polymer may be usually 500 × 10 ⁴ or less (eg, 150 × 10 ⁴ or less). The Mw may be 75 × 10 ⁴ or less.

Here, Mw means the standard polystyrene conversion value obtained by gel permeation chromatography (GPC). As a GPC apparatus, what is necessary is just to use the model name "HLC-8320GPC" (column: TSKgelGMH-H(S), Tosoh Corporation make), for example. It is the same also in the Example mentioned later. Said Mw may be Mw of the (meth)acrylic-type polymer in any one of an adhesive layer in an adhesive composition.

The pressure-sensitive adhesive composition according to some embodiments may be an active energy ray-curable pressure-sensitive adhesive composition. Examples of active energy rays as used herein include light such as ultraviolet rays, visible rays, and infrared rays, and radiation such as α rays, β rays, γ rays, electron beams, neutron rays, and X rays, polymerization reaction, crosslinking reaction , and energy rays having energy capable of causing a chemical reaction such as decomposition of an initiator.

As one preferable example of an active energy ray-curable adhesive composition, a photocurable adhesive composition is mentioned. The photocurable adhesive composition has the advantage that it can form easily even if it is a thick adhesive layer. Among them, an ultraviolet curable pressure-sensitive adhesive composition is preferable.

A photocurable pressure-sensitive adhesive composition typically contains at least a part (a part of a type of a monomer or a part of a quantity may be sufficient) among the monomer components of the composition in the form of a polymer.

The polymerization method at the time of forming the said polymer is not specifically limited, A conventionally well-known various polymerization method is employable suitably. For example, thermal polymerization (typically performed in presence of a thermal polymerization initiator), such as solution polymerization, emulsion polymerization, and bulk polymerization; photopolymerization performed by irradiating light such as ultraviolet rays (typically, it is carried out in the presence of a photopolymerization initiator); radiation polymerization performed by irradiating radiation such as β-rays and γ-rays; etc. can be appropriately employed. Among them, photopolymerization is preferable.

The photocurable adhesive composition which concerns on one preferable aspect contains the partial polymer of a monomer component. Such a partial polymer is typically a mixture of a polymer derived from a monomer component and an unreacted monomer, and preferably exhibits a syrupy form (viscous liquid). Hereinafter, the partial polymer of such properties is sometimes referred to as "monomer syrup" or simply "syrup".

The polymerization method in particular at the time of carrying out partial polymerization of a monomer component is not restrict|limited, The various polymerization methods as mentioned above can be used, selecting suitably. From the viewpoint of efficiency and simplicity, a photopolymerization method can be preferably employed. According to photopolymerization, the polymerization conversion rate (monomer conversion) of a monomer component can be easily controlled by polymerization conditions, such as the irradiation amount (light quantity) of light.

The polymerization conversion ratio of the monomer mixture in the said partial polymer is not specifically limited. The said polymerization conversion ratio can be made into 70 mass % or less, for example, and it is preferable to set it as 60 mass % or less. From the viewpoints of ease of preparation and coatability of the pressure-sensitive adhesive composition containing the partially polymerized product, usually, the polymerization conversion ratio is preferably 50 mass% or less, and preferably 40 mass% or less (for example, 35 mass% or less). .

Although the lower limit in particular of a polymerization conversion rate is not restrict|limited, Typically, it is 1 mass % or more, Usually, it is suitable to set it as 5 mass % or more.

The pressure-sensitive adhesive composition containing the partial polymerization product of the monomer component, for example, a monomer mixture containing the total amount of the monomer component used for the preparation of the pressure-sensitive adhesive composition is partially polymerized by a suitable polymerization method (for example, photopolymerization method) can be obtained

In addition, the pressure-sensitive adhesive composition containing the partial polymerization product of the monomer component may be a mixture of a partial or complete polymerization product of a monomer mixture containing a part of the monomer components used in the preparation of the pressure-sensitive adhesive composition, and the remaining monomer component or a mixture of the partial polymerization product. do. In addition, in this specification, a "completely polymerized product" means that a polymerization conversion ratio is more than 95 mass %.

<Oligomer>

The pressure-sensitive adhesive composition according to one embodiment of the present invention may contain at least one oligomer. The oligomer in one Embodiment of this invention is obtained by superposing|polymerizing the monomer composition containing at least the vinyl monomer which has an at least 1 type of dye structure in a side chain. That is, the said oligomer contains at least the vinyl monomer which has an at least 1 sort(s) of dye structure in a side chain as a monomer unit.

In order that the adhesive composition which concerns on one Embodiment of this invention uses the oligomer which contains the vinyl monomer which has a dye structure in a side chain as a structural unit as a dye component, the deterioration of dispersibility at the time of using a pigment or dye, and a pigment|dye The bleed-out problem can be avoided.

As a vinyl monomer which has at least 1 sort(s) of dye structure in the said side chain, a (meth)acrylic-type monomer, an aromatic vinyl monomer, an aliphatic hydrocarbon monomer, etc. are mentioned. From a viewpoint of compatibility with a (meth)acrylic-type base polymer and maintaining transparency, Preferably, a (meth)acrylic-type monomer is mentioned.

It does not restrict|limit especially as a (meth)acrylic-type monomer. For example, the above-mentioned various (meth)acrylic acid C _1-20 alkylester; The above-mentioned various alicyclic hydrocarbon group containing (meth)acrylates; The above-mentioned various aromatic hydrocarbon group containing (meth)acrylates; (meth)acrylate obtained from terpene compound derivative alcohol; (meth)acrylic monomers, such as these are mentioned. These can be used individually by 1 type or in combination of 2 or more type.

It does not restrict|limit especially as an aromatic vinyl monomer. For example, styrene-type monomers, such as styrene, chlorostyrene, chloromethylstyrene, and (alpha)-methylstyrene, etc. are mentioned. These can be used individually by 1 type or in combination of 2 or more type.

The aliphatic hydrocarbon monomer is not particularly limited. For example, an olefin monomer, a diene monomer, etc. are mentioned. These can be used individually by 1 type or in combination of 2 or more type.

As an oligomer in one Embodiment of this invention, you may contain other monomers other than the vinyl monomer which has in the said side chain at least 1 type of pigment|dye structure. As such a monomer, similarly to the above, it does not restrict|limit in particular. For example, a (meth)acrylic-type monomer, an aromatic vinyl monomer, an aliphatic hydrocarbon monomer, etc. are mentioned.

The oligomer in one embodiment of the present invention WHEREIN: It is preferable that it is 0.1 mass part or more per 100 mass parts of oligomers, and, as for the vinyl monomer which has at least 1 type of dye structure in the said side chain, it is more preferable that it is 1 mass part or more, It is more preferable that it is 5 mass parts or more.

Moreover, from a compatibility viewpoint with a base polymer, it is preferable that it is 90 mass parts or less, It is more preferable that it is 80 mass parts or less, It is still more preferable that it is 70 mass parts or less.

As an oligomer in one Embodiment of this invention, it is preferable that it is a (meth)acrylic-type oligomer.

The homopolymer of the (meth)acrylic-type monomer which has at least 1 type of pigment|dye structure in a side chain may be sufficient as such a (meth)acrylic-type oligomer.

Moreover, the copolymer of "a vinyl monomer which has at least 1 type of dye structure in a side chain" and "monomers other than a vinyl monomer which has at least 1 type of dye structure in a side chain" may be sufficient as such a (meth)acrylic-type oligomer. In this case, in the total amount of "a vinyl monomer having at least one type of dye structure in a side chain" and "monomers other than a vinyl monomer having at least one type of dye structure in a side chain", corresponding to the (meth)acrylic monomer It is preferable that a monomer is 50 mass % or more. More preferably, it is 70 mass % or more, More preferably, it is 80 mass % or more.

Said "monomer other than the vinyl monomer which has at least 1 sort(s) of dye structure in a side chain", Preferably it is "a (meth)acrylic-type monomer which does not have a dye structure in a side chain", More preferably, "a side chain" It is (meth)acrylic acid alkylester which does not have a pigment|dye structure".

In the case where the (meth)acrylic oligomer is a copolymer of "a vinyl monomer having at least one dye structure in the side chain" and "a monomer other than a vinyl monomer having at least one dye structure in the side chain", a preferred combination is a combination of "a (meth)acrylic-type monomer which has at least 1 type of dye structure in a side chain" and "a (meth)acrylic-type monomer which does not have a dye structure in a side chain." As a more preferable combination, it is a combination of "the (meth)acrylic-type monomer which has at least 1 type of dye structure in a side chain" and "(meth)acrylic acid alkylester which does not have a dye structure in a side chain."

The above-mentioned thing can be used for (meth)acrylic-type monomer and (meth)acrylic-acid alkylester.

Moreover, the (meth)acrylic-type oligomer is alkyl (meth)acrylate in which an alkyl group like isobutyl (meth)acrylate and t-butyl (meth)acrylate has a branched structure; alicyclic hydrocarbon group-containing (meth)acrylate and aromatic hydrocarbon group-containing (meth)acrylate; It is preferable from a viewpoint of an adhesive improvement to contain as a monomer unit the (meth)acrylic-type monomer which has a structure with comparatively large bulk, typified by these.

Moreover, in the case of employ|adopting an ultraviolet-ray at the time of the synthesis|combination of a (meth)acrylic-type oligomer or preparation of an adhesive layer, from the point which does not cause polymerization inhibition easily, the monomer which has a saturated hydrocarbon group at the ester terminal is preferable. For example, an alkyl (meth)acrylate in which an alkyl group has a branched structure or a saturated alicyclic hydrocarbon group-containing (meth)acrylate can be preferably used.

As a structural monomer component of a (meth)acrylic-type oligomer, in addition to the above-mentioned (meth)acrylic-type monomer, a functional group containing monomer can also be used as needed.

Examples of the functional group-containing monomer include a monomer having a nitrogen atom-containing heterocyclic ring such as N-vinyl-2-pyrrolidone and N-acryloylmorpholine; amino group-containing monomers such as N,N-dimethylaminoethyl (meth)acrylate; amide group-containing monomers such as N,N-diethyl (meth)acrylamide; carboxyl group-containing monomers such as AA and MAA; hydroxyl group-containing monomers such as 2-hydroxyethyl (meth)acrylate; can be heard

These functional group containing monomers can be used individually by 1 type or in combination of 2 or more type. When a functional group-containing monomer is used, the proportion of the functional group-containing monomer in the total monomer components constituting the (meth)acrylic oligomer may be, for example, 1 mass% or more, 2 mass% or more, or 3 mass% or more. Moreover, the ratio of the said functional group containing monomer can be 15 mass % or less, 10 mass % or less, or 7 mass % or less, for example.

The same dye structure may be sufficient as the pigment|dye structure which the oligomer in one Embodiment of this invention has in 1 molecule, and different pigment|dye structures may be sufficient as it. In one embodiment of the present invention, the different dye structures include not only dye structures having different dye skeletons, but also dye structures having the same dye skeleton and different types of substituents bonded to the dye skeleton. do.

In addition, in one Embodiment of this invention, a dye structure means the structure derived from a dye compound. For example, the structure which removed 1 or more arbitrary atoms which a dye compound has is mentioned.

There is no restriction|limiting in particular in the kind of dye structure, According to the objective, it can select suitably. The dye structure may be a structure derived from a dye compound having absorption in the visible region (preferably in a wavelength range of 400 to 700 nm, more preferably in a range of 400 to 650 nm). Moreover, the structure derived from the dye compound (preferably the compound which has a maximum absorption wavelength in the range of 700-1200 nm) which has absorption in an infrared region may be sufficient.

Especially, the structure derived from the dye compound which has absorption in a visible region is preferable.

Examples of the dye structure include a triarylmethane dye structure, a xanthene dye structure, an anthraquinone dye structure, a cyanine dye structure, a squarylium dye structure, a quinophthalone dye structure, a phthalocyanine dye structure, a subphthalocyanine dye structure, Azo pigment structure, pyrazolotriazole pigment structure, dipyrromethene pigment structure, isoindoline pigment structure, thiazole pigment structure, benzimidazolone pigment structure, perinone pigment structure, pyrrolopyrrole pigment structure, diketopyrrolopyrrole A dye structure, a diimmonium dye structure, a naphthalocyanine dye structure, a rylene dye structure, a dibenzoprone dye structure, a merocyanine dye structure, a croconium dye structure, an oxonol dye structure, etc. are mentioned.

Especially, a triarylmethane pigment|dye structure, a xanthene pigment|dye structure, and a cyanine pigment|dye structure are preferable.

The vinyl monomer in one Embodiment of this invention can have at least 1 sort(s) of the said pigment|dye structure in a side chain.

The oligomer in one Embodiment of this invention can be formed by superposing|polymerizing the monomer composition containing at least the vinyl monomer which has at least 1 type of dye structure in a side chain. The polymerization method and polymerization mode are not particularly limited, and various conventionally known polymerization methods (for example, solution polymerization, emulsion polymerization, bulk polymerization, photopolymerization, radiation polymerization, etc.) can be employed as appropriate modes.

The kind of polymerization initiator (for example, azo polymerization initiator) which can be used as needed is as illustrated about the synthesis|combination of a (meth)acrylic-type polymer in general. The amount of the polymerization initiator and the amount of the chain transfer agent (for example, mercaptans such as n-dodecyl mercaptan (NDM)) used arbitrarily are appropriately set based on common technical knowledge so as to achieve a desired molecular weight, detailed description is omitted. do.

It is preferable that the weight average molecular weights (Mw) of the oligomer in one Embodiment of this invention are 1,000-50,000 from a compatible viewpoint with a base polymer. The said weight average molecular weight (Mw) becomes like this. More preferably, it is 2,000 or more, More preferably, it is 3,000 or more. Moreover, the said weight average molecular weight (Mw) becomes like this. More preferably, it is 25,000 or less, More preferably, it is 10,000 or less.

Here, the weight average molecular weight (Mw) means a standard polystyrene conversion value obtained by gel permeation chromatography (GPC). As a GPC apparatus, what is necessary is just to use the model name "HLC-8320GPC" (column: TSKgelGMH-H(S), Tosoh Corporation make), for example. It is the same also in the Example mentioned later. Said Mw may be Mw of the oligomer in any one of an adhesive layer in an adhesive composition.

Moreover, the combination of a (meth)acrylic-type polymer and a (meth)acrylic-type oligomer is preferable from a viewpoint that the combination of a base polymer and an oligomer in one Embodiment of this invention has good compatibility.

From the viewpoint of colorability, the pressure-sensitive adhesive composition according to an embodiment of the present invention contains 0.01 parts by mass or more of the oligomer with respect to 100 parts by mass of the base polymer, more preferably 1 part by mass or more, It is more preferable to contain 5 mass parts or more.

Moreover, from a viewpoint of the influence on physical properties, such as adhesive force, it is suitable that content of the said oligomer shall normally be 100 mass parts or less, Preferably it is 90 mass parts or less, More preferably, it is 80 mass parts or less.

(Other Ingredients)

The pressure-sensitive adhesive composition according to one embodiment of the present invention is a range in which the effects of the present invention are not impaired, and if necessary, a tackifying resin (for example, rosin-based, petroleum-based, terpene-based, phenol-based, and ketone-based) Various additives common in the field of pressure-sensitive adhesive compositions, such as tackifying resins, such as system, viscosity modifiers (e.g., thickeners), leveling agents, plasticizers, fillers, stabilizers, preservatives, and anti-aging agents, may be contained as other optional components. have. As for such various additives, conventionally known ones can be used by a conventional method, and since they do not particularly characterize the present invention, detailed description thereof is omitted.

Moreover, the technique which concerns on this aspect can exhibit favorable adhesive force, without using the tackifying resin mentioned above. Therefore, content of the said tackifying resin in an adhesive composition is less than 10 mass parts with respect to 100 mass parts of base polymers, Furthermore, it can be made into less than 5 mass parts.

The content of the tackifying resin may be less than 1 part by mass (for example, less than 0.5 parts by mass) or less than 0.1 parts by mass (0 parts by mass or more and less than 0.1 parts by mass), and the pressure-sensitive adhesive composition contains no tackifying resin it may not be

It is preferable that the quantity of components other than the base polymer which the adhesive composition which concerns on one Embodiment of this invention occupies in an adhesive composition is restrict|limited from a viewpoint of improving transparency and making coloring remarkable with a pigment|dye.

The technique related to this aspect WHEREIN: The quantity of components other than the base polymer in an adhesive composition is 30 mass % or less normally, it is suitable that it is 15 mass % or less, Preferably it is 12 mass % or less (for example, 10 mass %) % or less).

5 mass % or less may be sufficient, 3 mass % or less may be sufficient as the quantity of components other than the base polymer in the adhesive composition which concerns on one aspect, and 1.5 mass % or less (for example, 1 mass % or less) may be sufficient as it. As described above, the composition in which the amount of components other than the base polymer is limited can be preferably employed for the pressure-sensitive adhesive composition according to the present aspect.

<Adhesive layer>

The pressure-sensitive adhesive layer according to one embodiment of the present invention is formed from the pressure-sensitive adhesive composition. A schematic cross-sectional view of a configuration example of the pressure-sensitive adhesive layer 11 is shown in FIG. 1 .

The pressure-sensitive adhesive layer may be a cured layer of the pressure-sensitive adhesive composition. That is, after providing (for example, application|coating) an adhesive composition to a suitable surface, this adhesive layer can be formed by performing hardening process suitably. When performing two or more types of hardening treatments (drying, crosslinking, polymerization, etc.), these can be performed simultaneously or over multiple steps.

In the pressure-sensitive adhesive composition using the partial polymerization product (polymer syrup) of the monomer component, a final copolymerization reaction is typically performed as the curing treatment described above. That is, the partial polymer is subjected to a new copolymerization reaction to form a complete polymer.

For example, if it is a photocurable adhesive composition, light irradiation will be performed. If necessary, curing treatment such as crosslinking and drying may be performed.

For example, when it is necessary to dry the photo-curable pressure-sensitive adhesive composition (for example, in the case of a photo-curable pressure-sensitive adhesive composition in which a partial polymer of a monomer component is dissolved in an organic solvent), the composition is dried and then photo-cured. should do

In the pressure-sensitive adhesive composition using a completely polymerized product, typically, as the curing treatment, drying (heat drying), crosslinking, and the like are performed as needed. In the case of a solvent-type adhesive composition to which photocurability (photocrosslinking) was imparted by addition of a polyfunctional monomer, after drying the composition, photocuring may be performed.

Here, after drying the said composition, the after-mentioned adhesive sheet obtained through the said drying may be pasted together to a to-be-adhered body. The adhesive sheet mentioned later can be used in the aspect of sticking to the to-be-adhered body by the method including photocuring after bonding to the to-be-adhered body.

The adhesive layer of the multilayered structure of two or more layers can be produced by bonding together the previously formed adhesive layers. Or an adhesive composition may be apply|coated on the 1st adhesive layer formed previously, the adhesive composition may be hardened, and a 2nd adhesive layer may be formed.

When the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet to be described later used in the pasting aspect to be photo-cured after bonding to an adherend has a multilayer structure, the photo-curing pressure-sensitive adhesive layer includes a part of the layer (for example, one layer) included in the multilayer structure. ) or all layers.

Application of the said adhesive composition can be performed using conventional coaters, such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, and a spray coater, for example.

In the adhesive sheet of the form with a base material mentioned later, as a method of forming an adhesive layer on a base material, you may use the direct method of directly applying an adhesive composition to the base material to form an adhesive layer, and the adhesive layer formed on the peeling surface. A transfer method may be used in which a substrate is transcribed.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, and may be, for example, 3 µm to 2000 µm.

From the viewpoint of adhesion with an adherend such as step followability, in some embodiments, the thickness of the pressure-sensitive adhesive layer may be, for example, 5 µm or more, preferably 10 µm or more, preferably 20 µm or more, more preferably 30 μm or more. The thickness of an adhesive layer may be 50 micrometers or more, may be more than 50 micrometers, may be sufficient as 70 micrometers or more, 100 micrometers or more may be sufficient, and 120 micrometers or more may be sufficient as it.

In addition, from the viewpoint of preventing the occurrence of glue residue due to cohesive failure of the pressure-sensitive adhesive layer, in some embodiments, the thickness of the pressure-sensitive adhesive layer may be, for example, 1000 µm or less, 700 µm or less, or 500 µm or less. , may be 300 µm or less, 200 µm or less, or 170 µm or less. The technique concerning this aspect can be implemented preferably also in the form of the adhesive sheet mentioned later whose thickness of an adhesive layer is 130 micrometers or less, 90 micrometers or less, and 60 micrometers or less (for example, 40 micrometers or less).

In addition, in the adhesive sheet mentioned later which has an adhesive layer which has a multilayer structure of two or more layers, the thickness of the said adhesive layer means the thickness from the adhesive surface affixed to a to-be-adhered body to the surface on the opposite side to the adhesive surface.

<Adhesive sheet>

The adhesive sheet which concerns on one Embodiment of this invention has the said adhesive layer. The pressure-sensitive adhesive sheet of one embodiment of the present invention may be a pressure-sensitive adhesive sheet with a base material in which the pressure-sensitive adhesive layer is provided on one or both sides of a sheet-like base material (support), and the pressure-sensitive adhesive sheet without a base material such as a form in which the pressure-sensitive adhesive layer is held on a release sheet It may be a sheet. The concept of the adhesive sheet referred to herein may include what is referred to as an adhesive tape, an adhesive label, an adhesive film, and the like.

In addition, although the pressure-sensitive adhesive layer is typically formed continuously, it is not limited to such a form, For example, the pressure-sensitive adhesive layer formed in a regular or random pattern such as dots and stripes may be used. Moreover, roll shape may be sufficient as the adhesive sheet of one Embodiment of this invention, and sheet shape may be sufficient as it. Alternatively, the pressure-sensitive adhesive sheet may be further processed into various shapes.

(write)

The pressure-sensitive adhesive sheet according to some embodiments may be in the form of a pressure-sensitive adhesive sheet with a base material including a base material bonded to the other rear surface of the pressure-sensitive adhesive layer. In FIG. 2, in the adhesive sheet which concerns on one Embodiment of this invention, the schematic sectional drawing of one structural example in which the adhesive layer is formed on the single side|surface of a base material is shown.

The adhesive sheet 1 shown in FIG. 2 is equipped with the base material 21 and the adhesive layer 11 formed on the single side|surface of the base material. As another aspect, the schematic sectional drawing of one structural example in which the adhesive layer is formed on both surfaces of the base material 21 in FIG. 3 is shown. The adhesive sheet 2 shown in FIG. 3 is equipped with the base material 21, and the 1st adhesive layer 11 and the 2nd adhesive layer 12 formed on both surfaces of the base material.

The material of the base material is not particularly limited, and may be appropriately selected according to the purpose of use of the pressure-sensitive adhesive sheet, the mode of use, and the like. Preferably, it is a transparent film.

Non-limiting examples of the substrate that can be used include a polyolefin film mainly composed of polyolefin such as polypropylene or ethylene-propylene copolymer, a polyester film composed mainly of polyester such as polyethylene terephthalate and polybutylene terephthalate, Plastic films, such as a polyvinyl chloride film which has polyvinyl chloride as a main component; Foam sheet which consists of foams, such as a polyurethane foam, a polyethylene foam, and a polychloroprene foam; Woven and nonwoven fabrics made of various fibrous materials (such as natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, and semi-synthetic fibers such as acetate) alone or by blending or the like; paper such as Japanese paper, fine paper, kraft paper, and crepe paper; metal foils such as aluminum foil and copper foil; and the like. The description of the structure which combined these may be sufficient.

As an example of the base material of such a composite structure, the base material of the structure in which a metal foil and the said plastic film were laminated|stacked, a plastic sheet reinforced with inorganic fibers, such as glass cloth, etc. are mentioned, for example.

Various films (henceforth a support film.) can be used preferably as a base material of the adhesive sheet which concerns on one Embodiment of this invention. The support film may be a porous film, such as a foam film or a nonwoven fabric sheet, or a non-porous film, or a film having a structure in which a porous layer and a non-porous layer are laminated.

In some aspects, as the support film, a resin film capable of independently maintaining a shape (self-supporting or non-dependent) can be preferably used as a base film.

Here, "resin film" means a resin film (voidless) that has a non-porous structure and typically contains substantially no air bubbles. Therefore, the said resin film is a concept distinguished from a foam film and a nonwoven fabric. A single-layer structure may be sufficient as the said resin film, and the multilayer structure (for example, three-layer structure) of two or more layers may be sufficient as it.

Examples of the resin material constituting the resin film include polyester, polyolefin, and polycycloolefin derived from a monomer having an aliphatic ring structure such as a norbornene structure, nylon 6, nylon 66, and partially aromatic polyamide. polyamide (PA), polyimide (PI), polyamideimide (PAI), polyether ether ketone (PEEK), polyether sulfone (PES), polyphenylene sulfide (PPS), polycarbonate (PC), etc. Fluorine resins, such as polyurethane (PU), ethylene-vinyl acetate copolymer (EVA), polystyrene, polyvinyl chloride, polyvinylidene chloride, and polytetrafluoroethylene (PTFE), Acrylic resins, such as polymethylmethacrylate and resins such as cellulose polymers such as diacetyl cellulose and triacetyl cellulose, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, and epoxy polymers.

The said resin film may be formed using the resin material containing individually 1 type of such resin, and may be formed using the resin material in which 2 or more types were blended. Unstretched may be sufficient as the said resin film, and the thing extended|stretched (for example, uniaxial stretching or biaxial stretching) may be sufficient as it.

Suitable examples of the resin material constituting the resin film include polyester-based resins, PPS resins, and polyolefin-based resins. Here, polyester-type resin means resin which contains polyester in the ratio which exceeds 50 mass %. Similarly, PPS resin means resin which contains PPS in the ratio of more than 50 mass %, and polyolefin resin means resin which contains polyolefin in the ratio of more than 50 mass %.

As the polyester-based resin, typically, a polyester-based resin containing, as a main component, a polyester obtained by polycondensing dicarboxylic acid and diol is used. Specific examples of the polyester-based resin include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polybutylene naphthalate.

As polyolefin resin, 1 type of polyolefin can be used individually or in combination of 2 or more types of polyolefins. The polyolefin may be, for example, a homopolymer of α-olefin, a copolymer of two or more α-olefins, and a copolymer of one or two or more α-olefins and other vinyl monomers.

Specific examples include ethylene-propylene copolymers such as polyethylene (PE), polypropylene (PP), poly-1-butene, poly-4-methyl-1-pentene, and ethylene propylene rubber (EPR), ethylene-propylene -butene copolymer, ethylene-butene copolymer, ethylene-vinyl alcohol copolymer, ethylene-ethyl acrylate copolymer, etc. are mentioned. Either low density (LD) polyolefins and high density (HD) polyolefins can be used.

Examples of the polyolefin resin film include an unstretched polypropylene (CPP) film, a biaxially oriented polypropylene (OPP) film, a low-density polyethylene (LDPE) film, a linear low-density polyethylene (LLDPE) film, a medium-density polyethylene (MDPE) film. , a high-density polyethylene (HDPE) film, a polyethylene (PE) film in which two or more types of polyethylene (PE) are blended, and a PP/PE blend film in which a polypropylene (PP) and polyethylene (PE) are blended.

As a specific example of the resin film which can be preferably used as a base material, a PET film, a PEN film, a PPS film, a PEEK film, a CPP film, and an OPP film are mentioned.

Preferred examples in terms of strength include PET film, PEN film, PPS film and PEEK film. A PET film is mentioned as a preferable example from viewpoints, such as availability, dimensional stability, and an optical characteristic.

Known additives such as light stabilizers, antioxidants, antistatic agents, colorants (dyes and pigments, etc.), fillers, slip agents, and anti-blocking agents can be blended with the resin film as needed. The compounding quantity of an additive is not specifically limited, According to the use of an adhesive sheet, etc., it can set suitably.

The manufacturing method of a resin film is not specifically limited. For example, conventionally well-known general resin film molding methods, such as extrusion molding, inflation molding, T-die cast molding, and calender roll molding, can be employ|adopted suitably.

The substrate may be substantially constituted from such a resin film. Alternatively, the substrate may include an auxiliary layer in addition to the resin film.

Examples of the auxiliary layer include an optical property adjusting layer (for example, an antireflection layer), a printed layer or laminate layer for imparting a desired appearance to a substrate or adhesive sheet, an antistatic layer, an undercoat layer, and a surface treatment such as a release layer layers can be taken. Moreover, the optical member mentioned later may be sufficient as the said base material.

The thickness of the base material is not particularly limited, and can be selected according to the purpose of use of the pressure-sensitive adhesive sheet, the mode of use, and the like. The thickness of the substrate may be, for example, 1000 µm or less, 500 µm or less, 100 µm or less, 70 µm or less, 50 µm or less, 25 µm or less, 10 µm or less, It may be 5 micrometers or less.

When the thickness of a base material becomes small, there exists a tendency for the flexibility of an adhesive sheet and the followability|trackability with respect to the surface shape of a to-be-adhered body to improve. Moreover, from viewpoints of handleability, workability, etc., the thickness of a base material may be 2 micrometers or more, for example, and may be more than 5 micrometers, or more than 10 micrometers. In some embodiments, the thickness of the substrate may be, for example, 20 µm or more, 35 µm or more, or 55 µm or more.

On the surface of the base material on the side to be joined to the pressure-sensitive adhesive layer, if necessary, conventionally known methods such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, application of a primer (primer), and antistatic treatment Surface treatment may be given.

Such surface treatment may be a treatment for improving the adhesion between the substrate and the pressure-sensitive adhesive layer, in other words, the anchoring property of the pressure-sensitive adhesive layer to the substrate. The composition of the primer is not particularly limited and can be appropriately selected from known ones.

Although the thickness in particular of an undercoat layer is not restrict|limited, Usually, 0.01 micrometer - 1 micrometer are suitable, and 0.1 micrometer - 1 micrometer are preferable.

The surface (hereinafter also referred to as the back surface) of the substrate on the opposite side to the side to be bonded to the pressure-sensitive adhesive layer is subjected to a conventionally known surface treatment such as peeling treatment, adhesion or tack improvement treatment, antistatic treatment, etc., if necessary. there may be

For example, by surface-treating the back surface of a base material with a peeling agent, the rewinding force of the adhesive sheet of the form wound in roll shape can be made easily. As the peeling agent, a silicone-based peeling agent, a long-chain alkyl-based peeling agent, an olefin-based peeling agent, a fluorine-based peeling agent, a fatty acid amide-based peeling agent, molybdenum sulfide, silica powder, and the like can be used.

(Releasable Liner)

In the adhesive sheet of one Embodiment of this invention, the said adhesive layer may be protected by the peeling liner (separator, peeling film) until use.

As the release liner, a conventional release paper or the like can be used, and it is not particularly limited. For example, a base material having a release treatment layer, a low-adhesive substrate made of a fluorine-based polymer, a low-adhesive base material made of a non-polar polymer, or the like can be used.

As a base material which has a peeling-treatment layer, the plastic film, paper, etc. surface-treated with peeling agents, such as a silicone type, a long-chain alkyl type, a fluorine type, and molybdenum sulfide, are mentioned, for example.

Examples of the fluorine-based polymer of the low-adhesive substrate made of the fluorine-based polymer include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene/hexafluoropropylene copolymer. a copolymer, and a chlorofluoroethylene/vinylidene fluoride copolymer.

As a non-polar polymer of the low adhesive base material which consists of a non-polar polymer, an olefin resin (For example, polyethylene, polypropylene, etc.) etc. are mentioned, for example. In addition, a release liner can be formed by a well-known thru|or a common method. Moreover, the thickness in particular of a release liner, etc. are not restrict|limited, either.

In the technique related to this aspect, the haze value of the pressure-sensitive adhesive sheet is suitably 10% or less, and may be 5% or less (for example, 3% or less). It is preferable that the said haze value is 1.0 % or less. Thus, a highly transparent adhesive sheet is preferable at the point in which the change of the external appearance at the time of discoloration or coloring is remarkable in one Embodiment of this invention.

The haze value of the adhesive sheet may be less than 1.0 %, less than 0.7 %, and 0.5 % or less (for example, 0 to 0.5 %) may be sufficient as it. These haze values regarding an adhesive sheet can be preferably applied also to the haze value of the adhesive layer in the technique which concerns on this aspect.

Here, the "haze value" refers to the ratio of the diffusely transmitted light to the total transmitted light when the measurement object is irradiated with visible light. Also called blur. A haze value can be represented by the following formula|equation.

Th [%] = Td/Tt × 100

In the above formula, Th is haze value [%], Td is scattered light transmittance, and Tt is total light transmittance. The haze value can be measured in accordance with the method described in Examples described later. The haze value can be adjusted, for example, by selection of the composition and thickness of the pressure-sensitive adhesive layer.

The technique which concerns on this aspect can be used suitably for an electronic member use, an optical member use, a building member use, etc., for example.

[Example]

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in more detail using an Example.

<Preparation of the pressure-sensitive adhesive composition>

[Preparation of adhesive solution]

(Adhesive solution (A1))

In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirring device, 97 parts by mass of n-butylacrylate (BA), 2 parts by mass of acrylic acid (AA), and 4-hydroxybutylacrylate (4HBA) as a monomer component ) 1 part by mass, 122 parts by mass of ethyl acetate as a polymerization solvent, 0.2 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) as a thermal polymerization initiator, and solution polymerization in a nitrogen atmosphere, Mw An adhesive solution (A1) containing a (meth)acrylic polymer having a value of 700,000 was obtained.

(Adhesive solution (A2))

Except having made monomer component into 95 mass parts of n-butylacrylate (BA), 5 mass parts of acrylic acid (AA), and 0 mass parts of 4-hydroxybutyl acrylate (4HBA), it is similar to preparation of adhesive solution (A1) Then, Mw prepared the adhesive solution (A2) of 650,000.

(Adhesive solution (A3))

Except having made the monomer component into 95 mass parts of n-butylacrylate (BA), 0 mass parts of acrylic acid (AA), and 5 mass parts of 4-hydroxybutyl acrylate (4HBA), it is similar to preparation of the adhesive solution (A1) Then, Mw prepared the adhesive solution (A3) whose Mw is 600,000.

The mixing|blending of the said adhesive solution is put together in the following Table 1, and is shown.

[Preparation of dye oligomer solution]

(Dye oligomer solution (B1))

In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirring device, 90 parts by mass of n-butyl acrylate (BA) as a monomer component, and a blue polymerizable dye RDW- which is a vinyl monomer having a dye structure in the side chain 10 parts by mass of B01 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 5 parts by mass of n-dodecylmercaptan (NDM) as a chain transfer agent, and 122 parts by mass of ethyl acetate as a polymerization solvent are injected, and 2,2'-azobis as a thermal polymerization initiator Mw obtained the dye oligomer solution (B1) containing the (meth)acrylic-type blue dye oligomer whose Mw is 5,000 by injecting|throwing-in 0.2 mass part of isobutyronitrile (AIBN) and performing solution polymerization in nitrogen atmosphere.

(Dye oligomer solution (B2))

Mw obtained the dye oligomer solution (B2) whose Mw is 5,000 like preparation of the dye oligomer (B1) except having made polymerizable dye into 10 mass parts of yellow RDW-Y02 (made by Fujifilm Wako Pure Chemicals).

(Dye oligomer solution (B3))

A dye oligomer solution (B3) having an Mw of 1,300 was obtained in the same manner as in the preparation of the dye oligomer (B1) except that the amount of n-dodecyl mercaptan (NDM) was 20 parts by mass per 100 parts by mass of the monomer component.

(Dye oligomer solution (B4))

A dye oligomer solution (B4) having an Mw of 48,000 was obtained in the same manner as in the preparation of the dye oligomer (B1) except that the amount of n-dodecyl mercaptan (NDM) was 0.1 parts by mass per 100 parts by mass of the monomer component.

(Dye oligomer solution (B5))

A dye oligomer solution (B5) having an Mw of 600 was obtained in the same manner as in the preparation of the dye oligomer (B1) except that the amount of n-dodecyl mercaptan (NDM) used was 30 parts by mass per 100 parts by mass of the monomer component.

(Dye oligomer solution (B6))

A dye oligomer solution (B6) having an Mw of 120,000 was obtained in the same manner as in the preparation of the dye oligomer (B1), except that the amount of n-dodecyl mercaptan (NDM) used was 0.02 parts by mass per 100 parts by mass of the monomer component.

The mixing|blending of the said dye oligomer solution is put together in the following Table 2, and is shown.

[Preparation of the pressure-sensitive adhesive composition]

(Adhesive composition (C1))

To the pressure-sensitive adhesive solution (A1) obtained above, 1 part by mass of the dye oligomer solution (B1) and 0.8 parts by mass of the isocyanate-based crosslinking agent colonate L (manufactured by Tosoh) per 100 parts by mass of the polymer component used to prepare the solution, It mixed uniformly, and the adhesive composition (C1) was prepared.

(Adhesive composition (C2))

Except having made the usage-amount of the dye oligomer solution (B1) into 5 mass parts, it carried out similarly to preparation of the adhesive composition (C1), and prepared the adhesive composition (C2).

(Adhesive composition (C3))

The used adhesive solution was made into an adhesive solution (A2), and it carried out similarly to preparation of an adhesive composition (C2), except having used 0.08 mass parts (Mitsubishi Gas Chemicals) of tetrad C instead of 0.8 mass parts of colonate L, and carried out, and an adhesive A composition (C3) was prepared.

(Adhesive composition (C4))

Except having made the used adhesive solution into the adhesive solution (A3), it carried out similarly to preparation of the adhesive composition (C2), and prepared the adhesive composition (C4).

(Adhesive composition (C5))

As a dye oligomer solution used, except having made 2.5 mass parts and B2 2.5 mass parts for dye oligomer solution (B1), it carried out similarly to preparation of an adhesive composition (C2), and prepared the adhesive composition (C5).

(Adhesive composition (C6))

As the used dye oligomer solution, 2.5 parts by mass of the dye oligomer solution (B1), 2.5 parts by mass of the organic pigment Pigment Blue 15 (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.5 parts by mass of the dispersant Ajispar PB821 (manufactured by Ajinomoto Fine Techno) were added. Except for that, it carried out similarly to preparation of the adhesive composition (C2), and prepared the adhesive composition (C6).

(Adhesive composition (C7))

Except having made the used dye oligomer solution into dye oligomer solution (B3), it carried out similarly to preparation of the adhesive composition (C2), and prepared the adhesive composition (C7).

(Adhesive composition (C8))

Except having made the used dye oligomer solution into the dye oligomer solution (B4), it carried out similarly to preparation of the adhesive composition (C2), and prepared the adhesive composition (C8).

(Adhesive composition (C9))

Except having made the used dye oligomer solution into the dye oligomer solution (B5), it carried out similarly to preparation of the adhesive composition (C2), and prepared the adhesive composition (C9).

(Adhesive composition (C10))

Except having made the used dye oligomer solution into dye oligomer solution (B6), it carried out similarly to preparation of the adhesive composition (C2), and prepared the adhesive composition (C10).

(Adhesive composition (C11))

Except having used 1 mass part of organic pigment Pigment Blue 15 instead of the dye oligomer solution (B1), it carried out similarly to preparation of the adhesive composition (C1), and prepared the adhesive composition (C11).

(Adhesive composition (C12))

An organic pigment was prepared in the same manner as in the preparation of the pressure-sensitive adhesive composition (C11), except that 2.5 parts by mass of Pigment Blue 15 and 2.5 parts by mass of Pigment Yellow 74 (manufactured by Oakwood Products, Inc.) was carried out, and the pressure-sensitive adhesive composition (C12) was prepared. .

(Adhesive composition (C13))

Except not having used the dye oligomer solution (B1), it carried out similarly to preparation of the adhesive composition (C1), and prepared the adhesive composition (C13).

(Adhesive composition (C14))

Except having added 0.5 mass parts of dispersing agent Ajispa PB821 (made by Ajinomoto Fine Techno), it carried out similarly to preparation of an adhesive composition (C11), and prepared the adhesive composition (C14).

(Adhesive composition (C15))

Except having made the usage-amount of organic pigment Pigment Blue 15 into 5 mass parts, it carried out similarly to preparation of the adhesive composition (C14), and prepared the adhesive composition (C15).

(Adhesive composition (C16))

The used adhesive solution was made into an adhesive solution (A3), 0.08 parts of tetrad C (made by Mitsubishi Gas Chemical) was used instead of 0.8 mass parts of colonate L, and except having not used a dispersing agent, preparation of adhesive composition (C15) It carried out similarly to and prepared the adhesive composition (C16).

<Production of the adhesive sheet>

(Example 1)

The adhesive composition (C1) is apply|coated to the 38-micrometer-thick peeling film (R1) (Mitsubishi Resin Co., Ltd., MRF#38) whose single side|surface of the polyester film becomes a peeling surface, and it is dried at 135 degreeC for 2 minutes, and 30 micrometers in thickness of the pressure-sensitive adhesive layer was formed. By pasting a corona-treated polyethylene terephthalate (PET) film with a thickness of 75 µm to this pressure-sensitive adhesive layer, a PET film (support), an adhesive layer, and a release film (R1) were laminated in this order to obtain an adhesive sheet (1). .

(Examples 2 to 10)

Instead of the adhesive composition (C1), except having used the adhesive composition (C2-C10) respectively, it carried out similarly to Example 1, and produced the adhesive sheets (2-10).

(Comparative Examples 1 and 2)

Instead of the adhesive composition (C1), except having used the adhesive composition (C11, C12), respectively, it carried out similarly to Example 1, and produced the adhesive sheets 11 and 12.

(Reference Examples 1 to 4)

Instead of the adhesive composition (C1), except having used the adhesive composition (C13-C16), respectively, it carried out similarly to Example 1, and produced the adhesive sheets (13-16) which concern on each example.

<Evaluation of dispersibility>

About the dispersibility of the dye oligomer thru|or a well-known organic pigment in the adhesive sheets (1-16) produced above, as follows, the presence degree of an aggregate evaluated.

○ (Good dispersibility): In the 10 cm × 10 cm test piece, visually visible aggregates were not observed.

Δ (slightly good dispersibility): In a 10 cm × 10 cm test piece, less than 10 visually visible aggregates were confirmed.

x (poor dispersibility): In the 10 cm x 10 cm test piece, 10 or more aggregates visible with the naked eye were confirmed.

A result is shown in Table 3. In addition, in Table 3, "-" means that this evaluation was not implemented.

<Evaluation of bleed-out property>

About the bleed-out property of the adhesive sheets 1-16 produced above, the residual degree of the pigment|dye component with respect to the to-be-adhered body after peeling evaluated as follows. In addition, the area|region in which the pigment|dye component in the following evaluation remains was calculated|required by making specific gravity of an adhesive layer 1.17 g/cm<3> and measuring the weight change of the adhesive sheet before and behind peeling.

(Good bleed-out property): Residual|survival of a pigment|dye component was not confirmed in the peeling surface of 2.5 cm x 7 cm.

Δ (slightly good bleed-out property): Residual of the dye component was confirmed in an area of less than 10% on a peeling surface of 2.5 cm×7 cm.

x (poor bleed-out property): In the peeling surface of 2.5 cm x 7 cm, residual|survival of the pigment|dye component was confirmed in 10% or more of area|region.

A result is shown in Table 3. In addition, in Table 3, "-" means that this evaluation was not implemented.

<Measurement of adhesive force>

About the adhesive sheets (1-16) produced above, the adhesive force was measured. The measurement of adhesive force cut|disconnected the adhesive sheets 1-16 so that it might become 25 mm in width and 10 cm in length, respectively, and peeled and removed the release liner.

Then, each adhesive sheet was reciprocated by 1 reciprocating with a 2 kg roller, and was crimped|bonded and affixed to alkali glass.

Using a tensile tester (AUTOGRAPH AGS-X, manufactured by Shimadzu Corporation), the force when peeling at a peeling angle of 180 degrees and a peeling rate of 300 mm/min was measured as adhesive force (N/25 mm).

A result is shown in Table 3. In addition, in Table 3, "-" means that this measurement was not performed.

The adhesive sheets of Examples 1-10 containing a dye oligomer were favorable in both dispersibility and bleed-out property. Especially, in Examples 1-8 whose weight average molecular weights (Mw) of a dye oligomer are 1,000-50,000, both dispersibility and bleed-out property were especially favorable. Moreover, although the adhesive sheet of Example 6 contained a pigment, since it contained a dispersing agent together, the favorable result was obtained.

On the other hand, since the adhesive sheets of Comparative Examples 1 and 2 contained a pigment rather than a dye oligomer, both dispersibility and bleed-out property were poor.

In addition, the adhesive sheet of Reference Examples 2 and 3 is adding a dispersing agent to the adhesive composition in Comparative Example 1. Therefore, in the adhesive sheet of Comparative Example 1, both dispersibility and bleed-out property were poor, but in the adhesive sheet of Reference Examples 2 and 3, both dispersibility and bleed-out property were favorable. Moreover, since the adhesive sheet containing a high acid value polymer was used for the adhesive sheet of Reference Example 4, both dispersibility and bleed-out property were favorable.

As mentioned above, although various embodiment was demonstrated, referring drawings, it cannot be overemphasized that this invention is not limited to such an example. It is clear that a person skilled in the art can imagine various changes or modifications within the scope described in the claims, and it is understood that they naturally fall within the technical scope of the present invention. Moreover, you may combine each component in the said embodiment arbitrarily in the range which does not deviate from the meaning of invention.

In addition, this application is based on the Japanese patent application (Japanese Patent Application No. 2019-065069) for which it applied on March 28, 2019, The content is taken in as a reference during this application.

1, 2: adhesive sheet
11, 12: adhesive layer
21: description

Claims (9)

A pressure-sensitive adhesive composition comprising a base polymer and at least one oligomer,
The said oligomer is an oligomer obtained by superposing|polymerizing the monomer composition containing at least the vinyl monomer which has at least 1 type of dye structure in a side chain, The adhesive composition characterized by the above-mentioned. The method of claim 1,
The base polymer is a (meth)acrylic polymer, the pressure-sensitive adhesive composition. 3. The method according to claim 1 or 2,
The oligomer is a (meth)acrylic oligomer, the pressure-sensitive adhesive composition. 4. The method of claim 3,
The said (meth)acrylic-type oligomer is a homopolymer of the (meth)acrylic-type monomer which has at least 1 type of dye structure in a side chain, The adhesive composition. 4. The method of claim 3,
The pressure-sensitive adhesive composition in which the said (meth)acrylic-type oligomer is a copolymer of the (meth)acrylic-type monomer and (meth)acrylic-acid alkylester which have at least 1 type of dye structure in a side chain. 6. The method according to any one of claims 1 to 5,
The weight average molecular weight of the said oligomer is 1,000-50,000, the adhesive composition. The adhesive layer which consists of the adhesive composition in any one of Claims 1-6. The adhesive sheet provided with the adhesive layer of Claim 7. 9. The method of claim 8,
A pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive layer on a transparent film.

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