KR102458113B1 - Adhesive composition and adhesive film - Google Patents

Abstract

[Problem] To provide a pressure-sensitive adhesive composition capable of forming a pressure-sensitive adhesive layer having a short curing period, low staining properties, and suppressed heavy peeling.
[Solutions] The pressure-sensitive adhesive composition contains (A) a (meth)acrylic copolymer having a reactive functional group, (B) an isocyanate-based crosslinking agent, and (C) a metal chelate compound, and the (A) (meth)acrylic copolymer The coalescence is obtained by living radical polymerization, has a weight average molecular weight of 200,000 to 2 million, and is characterized by a molecular weight distribution (PDI) of less than 3.0.

Description

Adhesive composition and adhesive film

The present invention relates to an adhesive composition and an adhesive film.

Image display devices such as optical films, liquid crystal displays, plasma displays, organic EL (electroluminescence) displays, and touch panels used for liquid crystal display devices have surface protection (for example, scratches and dust during transportation, storage, and processing). · A functional film having functions such as protection from contamination and corrosion), anti-glare, anti-reflection, and scattering prevention (prevention of scattering of an adherend) is applied to the surface and used.

This functional film has an adhesive layer for pasting on an image display device on one side of a base film, and it is in the form of an adhesive film with a functional coating layer formed on the other side as needed. In addition, it is affixed on the peeling film until it affixes on the surface of an image display apparatus. In addition, the optical film used for a liquid crystal display device, for example, a polarizing plate, retardation plate, etc. is pasted on a liquid crystal cell using an adhesive.

As the pressure-sensitive adhesive, a (meth)acrylic pressure-sensitive adhesive comprising a (meth)acrylic acid ester-based copolymer and a crosslinking agent is used because of excellent optical properties and comparatively easy design of the pressure-sensitive adhesive. Moreover, in order to acquire durability in the environment under high temperature, high humidity, an isocyanate type crosslinking agent is used as a crosslinking agent.

Here, the (meth)acrylic pressure-sensitive adhesive has a problem in that contaminants derived from the pressure-sensitive adhesive layer remain on the adherend when the pressure-sensitive adhesive film is peeled from the adherend. This is considered to be due to the low molecular weight component which arises when manufacturing a (meth)acrylic acid ester type copolymer. Moreover, when an adhesive is heated, such a low molecular-weight component also raises the problem of raising adhesive force excessively. When an adhesive is heated by the use environment of the article to which the adhesive film was affixed, the adhesive force of an adhesive will rise and it will adhere firmly to a to-be-adhered body, and peeling will become difficult even after the purpose of use of an adhesive film is complete|finished. Moreover, even when peeling is possible, an adhesive will remain|survive on a to-be-adhered body, and will contaminate a to-be-adhered body. Therefore, the (meth)acrylic acid ester type copolymer with few low molecular weight components is calculated|required.

In general, (meth)acrylic acid ester-based copolymers are produced by free radical polymerization, but it is difficult to achieve uniformity in the composition of the copolymer, and as a result, many low molecular weight components (oligomers) are generated. Then, in patent document 1, using the (meth)acrylic acid ester type copolymer manufactured by the living radical polymerization method for an adhesive composition is proposed (patent document 1 (18th pages 5-10, 24-26) row)).

Moreover, when the (meth)acrylic acid ester type copolymer obtained by the living radical polymerization method is used, it is known that crosslinking delay and heavy peeling by the passage of time occur (see Patent Document 2 (Comparative Example 1, Comparative Example 5)) ). When a crosslinking delay arises, a long-term curing period is required, productivity of an adhesive film is inferior, and there exists a problem that the storage stability of an adhesive film and the workload at the time of use increase by making it heavy peeling. Then, in patent document 2, using the adhesive composition which consists of a (meth)acrylic acid ester type copolymer obtained by the living radical polymerization method, an isocyanate type crosslinking agent, and an organotin compound is proposed (patent document 2 (claim 1) ) Reference).

International Publication No. 2007/119884 Japanese Patent Laid-Open No. 2014-31442

However, also in the adhesive composition of patent document 2, the inhibitory effect of heavy peeling was not enough, and there existed room for examination. Moreover, although using an organotin compound is proposed in patent document 2, the crosslinking promoter which replaces an organotin compound is calculated|required from the concern about the toxicity.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pressure-sensitive adhesive composition capable of forming a pressure-sensitive adhesive layer having a short curing period, low staining properties, and suppressed heavy peeling.

The pressure-sensitive adhesive composition of the present invention capable of solving the above problems contains (A) a (meth)acrylic copolymer having a reactive functional group, (B) an isocyanate-based crosslinking agent, and (C) a metal chelate compound, (A) The (meth)acrylic copolymer is obtained by living radical polymerization, has a weight average molecular weight of 200,000 to 2,000,000, and has a molecular weight distribution (PDI) of less than 3.0.

The pressure-sensitive adhesive composition of the present invention, by blending the (C) metal chelate compound, even when a copolymer obtained by living radical polymerization is used, the curing period is short, has low staining properties, and the pressure-sensitive adhesive layer in which heavy peeling is suppressed A pressure-sensitive adhesive composition that can be formed is obtained.

The said adhesive composition can be used suitably as an object for optics. The present invention also includes a base film and an adhesive film having a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition. Moreover, the image display apparatus provided with the said adhesive film is also contained in this invention.

The adhesive composition of this invention has a short curing period at the time of forming an adhesive layer. Moreover, the adhesive layer formed from the adhesive composition of this invention has low stain|pollution|contamination property, and the heavy peeling with respect to a peeling film is suppressed.

Hereinafter, an example of the preferable form which implemented this invention is demonstrated. However, the following embodiment is a simple illustration. The present invention is not limited to the following embodiments at all.

In this invention, "(meth)acryl" means "at least one of an acryl and methacryl". "(meth)acrylate" means "at least one of an acrylate and a methacrylate". "(meth)acryloyl" means "at least one of acryloyl and methacryloyl." A "vinyl monomer" refers to a monomer having a carbon-carbon double bond capable of radical polymerization in a molecule. The "structural unit derived from a vinyl monomer" refers to a structural unit in which a radically polymerizable carbon-carbon double bond of a vinyl monomer is polymerized to form a carbon-carbon single bond. The "structural unit derived from (meth)acrylate" refers to a structural unit in which a radical polymerizable carbon-carbon double bond of (meth)acrylate polymerizes to form a carbon-carbon single bond. The "structural unit derived from a (meth)acryl monomer" refers to a structural unit in which a radically polymerizable carbon-carbon double bond of a (meth)acryl monomer polymerizes to form a carbon-carbon single bond. The "structural unit derived from a vinyl monomer" refers to a structural unit in which a radically polymerizable carbon-carbon double bond of a vinyl monomer is polymerized to form a carbon-carbon single bond.

<1. Adhesive composition>

The adhesive composition of this invention contains (A) the (meth)acrylic-type copolymer which has a reactive functional group, (B) an isocyanate-type crosslinking agent, and (C) a metal chelate compound. And the said (A) (meth)acrylic-type copolymer is obtained by living radical polymerization, a weight average molecular weight is 200,000-2 million, and molecular weight distribution (PDI) is less than 3.0.

The adhesive composition of this invention can shorten the curing period at the time of forming an adhesive layer by mix|blending (C) a metal chelate compound. Moreover, the adhesive composition of this invention can suppress heavy peeling with respect to a peeling film or to-be-adhered body, even when using the copolymer obtained by living radical polymerization by mix|blending (C) a metal chelate compound.

Each structural component of the adhesive composition of this invention, etc. are demonstrated below.

((A) (meth)acrylic copolymer having a reactive functional group)

(A) A (meth)acrylic copolymer having a reactive functional group used in the present invention (hereinafter, simply referred to as "(A) copolymer") is obtained by living radical polymerization, and has a weight average molecular weight of 20 It is 10,000-2 million, molecular weight distribution (Mw/Mn) is less than 3.0, and it is a (meth)acrylic-type copolymer which has a reactive functional group.

The (meth)acrylic copolymer may be any copolymer having as a main component (50% by mass or more) a structural unit derived from a (meth)acrylic monomer, and may contain a structural unit derived from a vinyl monomer other than the (meth)acrylic monomer. can In 100 mass % of the whole copolymer, 80 mass % or more is preferable, and, as for the content rate of the structural unit derived from the (meth)acryl monomer in the said (A) copolymer, 90 mass % or more is more preferable. Moreover, the said (A) copolymer may be comprised only with the structural unit derived from a (meth)acryl monomer.

The (A) copolymer is preferably a (meth)acrylic acid ester copolymer ((meth)acrylate copolymer). The (meth)acrylate-based copolymer may be a copolymer having a structural unit derived from (meth)acrylate as a main component (50% by mass or more), and a structural unit derived from a vinyl monomer other than (meth)acrylate. may contain. The said (meth)acrylate is an ester compound produced|generated from (meth)acrylic acid and the compound which has a hydroxyl group. In 100 mass % of the whole copolymer, 80 mass % or more is preferable, and, as for the content rate of the structural unit derived from (meth)acrylate in the said (A) copolymer, 90 mass % or more is more preferable. Moreover, the said (A) copolymer may be comprised only with the structural unit derived from (meth)acrylate.

The said reactive functional group is a functional group which can react with the isocyanate group which the (B) isocyanate type crosslinking agent mentioned later has. Examples of the reactive functional group include one or more selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, a phosphine group, and an epoxy group, preferably a hydroxyl group and/or is a carboxyl group.

The amount of reactive functional groups per 100 g of the copolymer (A) is preferably 0.5 mmol / 100 g or more, more preferably 5 mmol / 100 g or more, still more preferably 10 mmol / 100 g or more, and particularly preferably 15 mmol / 100 g or more. , 150 mmol/100g or less is preferable, More preferably, it is 100 mmol/100g or less, More preferably, it is 70 mmol/100g or less, Especially preferably, it is 50 mmol/100g or less. If the amount of reactive functional groups is 0.5 mmol/100 g or more, it is excellent in durability of an adhesive composition, and it is excellent in the adhesiveness to a to-be-adhered body that it is 150 mmol/100g or less.

The copolymer (A) has a reactive functional group. That is, the said copolymer (A) contains the structural unit (a-1) which has a reactive functional group in the structure. The number of structural units (a-1) which has the said reactive functional group may be one, and may have 2 or more types. You may have the said reactive functional group in either a structural unit derived from a (meth)acryl monomer (preferably a (meth)acrylate monomer), or a structural unit derived from vinyl monomers other than a (meth)acryl monomer. That is, the structural unit (a-1) having a reactive functional group is a structural unit derived from a (meth)acryl monomer (preferably a (meth)acrylate monomer) having a reactive functional group, or (meth) having a reactive functional group ) Structural units derived from vinyl monomers other than an acryl monomer are mentioned.

The content of the structural unit derived from the vinyl monomer having a reactive functional group in the copolymer (A) (structural unit (a-1) having a reactive functional group) is preferably 0.1 mass% or more in 100 mass% of the total copolymer and more preferably 0.5 mass % or more, still more preferably 1 mass % or more, particularly preferably 3 mass % or more, preferably 20 mass % or less, more preferably 15 mass % or less, still more preferably Preferably it is 10 mass % or less, Especially preferably, it is 8 mass % or less. When the content of the structural unit (a-1) is within the above range, an adhesive composition excellent in the balance between the adhesion to an adherend and the durability can be obtained. In addition, vinyl monomers other than the (meth)acryl monomer which has a reactive functional group and the (meth)acryl monomer which has a reactive functional group are contained in the vinyl monomer which has a reactive functional group.

As said (meth)acryl monomer, (b1) the (meth)acryl monomer which does not have a reactive functional group, (b2) the (meth)acryl monomer which has a reactive functional group is mentioned. These monomers may be used independently and may use 2 or more types together. As the (b1) (meth)acryl monomer not having a reactive functional group, (b1-1) a (meth)acrylate monomer not having a reactive functional group is preferable. As a (meth)acryl monomer which has said (b2) reactive functional group, the (meth)acrylate monomer which has (b2-1) reactive functional group is mentioned.

As the (b1) (meth)acrylic monomer not having a reactive functional group, (meth)acrylate having a linear alkyl group, (meth)acrylate having a branched alkyl group, (meth)acrylate having an alkoxy group, polyethylene glycol structure (meth)acrylate having a unit, (meth)acrylate having an alicyclic hydrocarbon group, (meth)acrylate having an aromatic group, (meth)acrylate having an oxygen-containing heterocyclic group, (meth)acrylic having a tertiary amino group a rate, (meth)acrylamides, etc. are mentioned. Among them, (meth)acrylate having a linear alkyl group, (meth)acrylate having a branched alkyl group, (meth)acrylate having an alicyclic hydrocarbon group, (meth)acrylate having an aromatic group, (meth)acrylamide is preferable

As the (meth)acrylate having a linear alkyl group, (meth)acrylate having a linear alkyl group having 1 to 20 carbon atoms in the linear alkyl group is preferable, and the linear alkyl group having 1 to 10 carbon atoms in the linear alkyl group is preferable. (meth)acrylate having As (meth)acrylate which has the said linear alkyl group, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-hexyl (meth)acrylate ) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, decyl (meth) acrylate, n-lauryl (meth) acrylate, n-stearyl (meth) acrylate, etc. (meth)acrylic acid linear alkylester is mentioned.

The (meth)acrylate having a branched alkyl group is preferably a (meth)acrylate having a branched alkyl group having 3 to 20 carbon atoms in the branched alkyl group, and a branched alkyl group having 3 to 10 carbon atoms in the branched alkyl group. (meth)acrylate having Examples of the (meth)acrylate having a branched alkyl group include isopropyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isooctyl ( (meth)acrylic acid branched chain alkylesters, such as meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, and isodecyl (meth)acrylate, are mentioned.

As (meth)acrylate which has the said alkoxy group, (meth)acrylic-acid alkoxyalkyl esters, such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate, are mentioned.

Examples of the (meth)acrylate having the polyethylene glycol structural unit include polyethylene glycol (degree of polymerization = 1 to 10 (preferably 1 to 5)) methyl ether (meth) acrylate, polyethylene glycol (degree of polymerization = 1 to 10 (preferably) 1 to 5)) ethyl ether (meth) acrylate, polyethylene glycol (degree of polymerization = 1 to 10 (preferably 1 to 5)) propyl ether (meth) acrylate, polypropylene glycol (degree of polymerization = 1 to 10 (preferably) Preferably 1 to 5)) methyl ether (meth) acrylate, polypropylene glycol (degree of polymerization = 1 to 10 (preferably 1 to 5)) ethyl ether (meth) acrylate, polypropylene glycol (degree of polymerization = 1 to 10) (preferably 1-5)) propyl ether (meth)acrylate etc. are mentioned.

Examples of the alicyclic hydrocarbon group include a saturated monocyclic hydrocarbon group, an unsaturated monocyclic hydrocarbon group, and a cross-linked hydrocarbon group. As for the (meth)acrylate which has the said alicyclic hydrocarbon group, the compound which an alicyclic hydrocarbon group directly couple|bonds with the (meth)acryloyloxy group is preferable. As the (meth)acrylate having an alicyclic hydrocarbon group, (meth)acrylate having a saturated monocyclic hydrocarbon group is preferable, and (meth)acrylate having a saturated monocyclic hydrocarbon group having 6 to 12 carbon atoms is more preferable. Examples of the (meth)acrylate having an alicyclic hydrocarbon group include (meth)acryl having a saturated monocyclic hydrocarbon group such as cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, and cyclododecyl (meth)acrylate. Rate; Bornyl (meth) acrylate, isobornyl (meth) acrylate, 1-adamantyl (meth) acrylate, 2-adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, norbornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, etc. (meth)acrylates having a crosslinked hydrocarbon group are mentioned.

As (meth)acrylate which has the said alicyclic hydrocarbon group, (meth)acrylate which has a cyclic alkyl group, and (meth)acrylate which has a polycyclic structure are mentioned. As (meth)acrylate which has the said cyclic alkyl group, it is preferable that it is a (meth)acrylate which has a C6-C12 cyclic alkyl group of a cyclic alkyl group. Examples of the cyclic alkyl group include a cyclic alkyl group having a monocyclic structure (eg, a cycloalkyl group), and may further have a chain portion. As a specific example of the (meth)acrylate which has a cyclic alkyl group of monocyclic structure, (meth)acrylic acid cyclic alkylesters, such as cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, and cyclododecyl (meth)acrylate can be heard

The (meth)acrylate having a polycyclic structure is preferably a (meth)acrylate having a polycyclic structure having 6 to 12 carbon atoms in the polycyclic structure. Examples of the polycyclic structure include a cyclic alkyl group having a cross-linked structure (eg, adamantyl group, norbornyl group, isobornyl group), and may further have a chain portion. As a specific example of the (meth)acrylate which has a polycyclic structure, Bornyl (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-adamantyl (meth) Acrylate, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate, norbornyl (meth) acrylate, dicyclopentanyl (meth) acrylate , dicyclopentenyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and the like.

As (meth)acrylate which has the said aromatic group, it is preferable that it is a (meth)acrylate which has an aromatic group whose carbon number of an aromatic group is 6-12. As an aromatic group, an aryl group etc. are mentioned, Furthermore, you may have a chain|strand-shaped part like an alkylaryl group, an araryl group, an aryloxyalkyl group, etc. Examples of the (meth)acrylate having an aromatic group include a compound in which an aryl group is directly bonded to a (meth)acryloyloxy group, a compound in which an aralkyl group is directly bonded to a (meth)acryloyloxy group, and an alkylaryl group in a (meth)acryloyloxy group. and compounds to which the groups are directly bonded. As for carbon number of the said aryl group, 6-12 are preferable. As for carbon number of the said aralkyl group, 6-12 are preferable. As for carbon number of the said alkylaryl group, 6-12 are preferable. As (meth)acrylate which has an aromatic group, benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, etc. are mentioned.

As (meth)acrylate which has the said oxygen-containing heterocyclic group, it is preferable that it is (meth)acrylate which has an oxygen-containing heterocyclic group of a 4- to 6-membered ring. As a specific example of the (meth)acrylate which has an oxygen-containing heterocyclic group, tetrahydrofurfuryl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, (2-methyl-2- Ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, 2-[(2-tetrahydropyranyl)oxy]ethyl (meth)acryl and 1,3-dioxane-(meth)acrylate.

As (meth)acrylate which has the said tertiary amino group, 2-(dimethylamino)ethyl (meth)acrylate, N,N- dimethylaminopropyl (meth)acrylate, etc. are mentioned.

Examples of the (meth)acrylamides include N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-diisopropyl (meth)acrylamide, and (meth)acrylamide. , N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, N-octyl (meth) acrylamide, N -Methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, diacetone acrylamide, N- (meth)acryloylmorpholine etc. are mentioned. Although the said (meth)acrylamide is a (meth)acryl monomer, it is not contained in a (meth)acrylate monomer.

As the (b2) (meth)acryl monomer having a reactive functional group, a (meth)acryl monomer having a hydroxyl group (preferably (meth)acrylate monomer), a (meth)acryl monomer having a carboxyl group (preferably (meth) acrylate monomer), a (meth)acrylic monomer having a sulfonic acid group (preferably a (meth)acrylate monomer), a (meth)acrylic monomer having a phosphoric acid group (preferably a (meth)acrylate monomer), an epoxy group ( A meth)acrylic monomer (preferably a (meth)acrylate monomer) etc. are mentioned. Among these, the (meth)acryl monomer which has a hydroxyl group, and the (meth)acryl monomer which has a carboxy group are preferable.

Examples of the (meth)acrylic monomer having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl ( Meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, etc. Hydroxyalkyl (meth) acrylate of; (4-hydroxymethylcyclohexyl) methyl (meth) acrylate, such as hydroxyalkyl cycloalkane (meth) acrylate; Caprolactone addition of hydroxyalkyl (meth) acrylate water; and the like. Among these, hydroxyalkyl (meth)acrylate is preferable, and (meth)acrylate which has a C1-C5 hydroxyalkyl group is more preferable.

Examples of the (meth)acrylic monomer having a carboxyl group include carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, and 2-(meth)acryloyloxy A monomer obtained by reacting (meth)acrylate having a hydroxyl group such as ethyl maleate or 2-(meth)acryloyloxyethylphthalate with an acid anhydride such as maleic anhydride, succinic anhydride, or phthalic anhydride, (meth)acrylic acid, etc. can be heard Among these, (meth)acrylic acid is preferable.

Ethyl sulfonate (meth)acrylate etc. are mentioned as a (meth)acryl monomer which has the said sulfonic acid group.

As a (meth)acryl monomer which has the said phosphoric acid group, (meth)acrylic-acid 2-(phosphonooxy)ethyl etc. are mentioned.

As (meth)acrylic acid ester which has the said epoxy group, glycidyl (meth)acrylate, 3, 4- epoxycyclohexylmethyl (meth)acrylate, etc. are mentioned.

As a vinyl monomer of the said (meth)acryl monomer, (b3) vinyl monomers other than a (meth)acryl monomer which does not have a reactive functional group, (b4) vinyl monomers other than a (meth)acryl monomer which has a reactive functional group are mentioned. These monomers may be used independently and may use 2 or more types together.

Examples of the vinyl monomer other than the (b3) (meth)acrylic monomer having no reactive functional group include an aromatic vinyl monomer, a vinyl monomer containing a heterocyclic ring, vinyl carboxylate, a vinyl monomer containing a tertiary amino group, and a quaternary ammonium salt group. vinyl monomers, vinylamides, α-olefins, dienes, and the like.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methoxystyrene, 2-hydroxymethylstyrene, and 1-vinylnaphthalene. .

Examples of the vinyl monomer containing the heterocyclic ring include 2-vinylthiophene, N-methyl-2-vinylpyrrole, 2-vinylpyridine, and 4-vinylpyridine.

As said vinyl carboxylate, vinyl acetate, a vinyl pivalate, a vinyl benzoate, etc. are mentioned.

Examples of the vinyl monomer containing the tertiary amino group include N,N-dimethylallylamine and the like.

Examples of the vinyl monomer containing the quaternary ammonium salt group include N-methacryloylaminoethyl-N,N,N-dimethylbenzylammonium chloride and the like.

Examples of the vinylamides include N-vinylformamide, N-vinylacetamide, 1-vinyl-2-pyrrolidone, and N-vinyl-ε-caprolactam.

Examples of the α-olefin include 1-hexene, 1-octene, and 1-decene.

Examples of the dienes include butadiene, isoprene, 4-methyl-1,4-hexadiene, and 7-methyl-1,6-octadiene.

Examples of the vinyl monomer other than the (b4) reactive functional group-containing (meth)acryl monomer include a vinyl monomer having a hydroxyl group, a vinyl monomer having a carboxy group, and a vinyl monomer containing an epoxy group.

Examples of the vinyl monomer having a hydroxyl group include p-hydroxystyrene and allyl alcohol.

Examples of the vinyl monomer having a carboxyl group include crotonic acid, maleic acid, itaconic acid, citraconic acid, cinnamic acid, and (meth)acrylic acid.

Examples of the vinyl monomer containing the epoxy group include 2-allyloxirane, glycidyl vinyl ether, and 3,4-epoxycyclohexyl vinyl ether.

Any of a random copolymer, a block copolymer, a graft copolymer, etc. may be sufficient as said (A) copolymer.

The weight average molecular weight (Mw) of the copolymer (A) is 200,000 or more, preferably 400,000 or more, more preferably 500,000 or more, still more preferably 600,000 or more, 2 million or less, preferably is 1.8 million or less, more preferably 1.5 million or less, still more preferably 1.3 million or less. (A) If the Mw of the copolymer is less than 200,000, cohesive force is insufficient, and there is a risk of deterioration of heat resistance or contaminating the surface of the adherend, and when Mw exceeds 2,000,000, the coating workability of the pressure-sensitive adhesive composition may deteriorate. The measuring method of a weight average molecular weight (Mw) is mentioned later.

The molecular weight distribution (PDI) of the copolymer (A) is less than 3.0, preferably less than 2.5, more preferably less than 2.4, and particularly preferably less than 2.0. The smaller the PDI is, the narrower the molecular weight distribution is, and the copolymer has an even molecular weight, and when the value is 1.0, the molecular weight distribution is the narrowest. When PDI is less than 3.0, compared with the molecular weight of the designed copolymer, content of a thing with a small molecular weight and a thing with a large molecular weight is low, and adhesive force improves. In addition, in this invention, molecular weight distribution (PDI) is a value computed by (weight average molecular weight (Mw))/(number average molecular weight (Mn)), and the measuring method of Mw and Mn is mentioned later.

As for the glass transition temperature (Tg) of the said (A) copolymer, -80 degreeC or more is preferable, More preferably, it is -70 degreeC or more, 20 degrees C or less is preferable, More preferably, it is 0 degreeC or less. When the glass transition temperature is -80 ° C. or higher, sufficient cohesive force is imparted to the pressure-sensitive adhesive composition, and the durability of the pressure-sensitive adhesive layer is improved. do.

The glass transition temperature (Tg) of the copolymer (A) is a value calculated by the following FOX formula (Formula (1)). In formula (1), Tg represents the glass transition temperature (degreeC) of a copolymer. Tgi represents the glass transition temperature (°C) when the vinyl monomer i forms a homopolymer. Wi represents the mass ratio of the vinyl monomer i in all the vinyl monomers forming the copolymer, and ?Wi=1. i is a natural number from 1 to n.

Table 1 shows the glass transition temperatures of representative homopolymers.

[Table 1]

The copolymer (A) is produced by radical polymerization of a vinyl monomer by a living radical polymerization method. In the conventional radical polymerization method (free radical polymerization method), as well as initiation reaction and growth reaction, loss of growth terminal activity occurs due to stop reaction and chain transfer reaction, which tends to result in a mixture of polymers of various molecular weights and non-uniform compositions. tends to In the living radical polymerization method, while maintaining the simplicity and versatility of the conventional radical polymerization method, stop reaction or chain transfer is unlikely to occur, and growth ends are grown without loss of activity, so precise control of molecular weight distribution and uniform composition The preparation of polymers is easy.

Therefore, it is considered that the copolymer manufactured by the living radical polymerization method has an advantage that there are few low molecular-weight components (oligomer), and when it uses for an adhesive composition, there is little contamination of a to-be-adhered body. In addition, since the reactive functional groups are uniformly distributed in the copolymer, the amount of reactive functional groups capable of reacting with the isocyanate-based crosslinking agent is increased in the copolymer prepared by the living radical polymerization method than in the copolymer prepared by the free radical polymerization method, It is considered that a delay occurs and a long curing period is required.

In the living radical polymerization method, it can be set as a random copolymer by using the mixture of each monomer (vinyl monomer) which comprises the said (A) copolymer. Moreover, it can also be set as a block copolymer by making the vinyl monomers which comprise a copolymer react sequentially. For example, in the case of a diblock copolymer, a method of preparing the first block first, and polymerizing the vinyl monomer constituting the second block in the first block; A method of preparing the second block first, and polymerizing the vinyl monomer constituting the first block in the second block; and the like. In addition, in the case of a triblock copolymer, the first block is first prepared, the first block is polymerized with the vinyl monomer constituting the second block, and the vinyl monomer constituting the third block is further polymerized to prepare a method, etc. can be heard

Examples of the living radical polymerization method include a method using a transition metal catalyst such as copper, ruthenium, nickel, iron or the like (ATRP method), depending on the method of stabilizing the polymerization growth terminal; a method using a sulfur-based reversible chain transfer agent (RAFT method); There is a method using an organic tellurium compound (TERP method) and the like. Since the ATRP method uses an amine-type complex, unless the acidic group of the vinyl monomer which has an acidic group is protected, it may not be used. In the RAFT method, when many types of vinyl monomers are used, it is difficult to achieve a low molecular weight distribution, and there may be problems such as a sulfur odor and coloration. Among these methods, it is preferable to use the TERP method from the viewpoint of diversity of vinyl monomers that can be used, molecular weight control in the polymer region, uniform composition, or coloring.

The TERP method is a method of polymerizing a radically polymerizable compound (vinyl monomer) using an organic tellurium compound as a chain transfer agent, for example, International Publication Nos. 2004/14848, International Publication Nos. 2004/14962, International Publication Nos. Publication No. 2004/072126, and International Publication No. 2004/096870.

Specific polymerization methods of the TERP method include the following (a) to (d).

(a) The method of superposing|polymerizing a vinyl monomer using the organic tellurium compound represented by Formula (1).

(b) The method of superposing|polymerizing a vinyl monomer using the mixture of the organic tellurium compound represented by Formula (1), and an azo polymerization initiator.

(c) A method of polymerizing a vinyl monomer using a mixture of the organic tellurium compound represented by the formula (1) and the organic ditelluride compound represented by the formula (2).

(d) A method of polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by Formula (1), an azo polymerization initiator, and an organic ditelluride compound represented by Formula (2).

[In Formula (1), R< ¹ > is a C1-C8 alkyl group, an aryl group, or an aromatic heterocyclic group. R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R ⁴ is an alkyl group having 1 to 8 carbon atoms, an aryl group, a substituted aryl group, an aromatic heterocyclic group, an alkoxy group, an acyl group, an amide group, an oxycarbonyl group, a cyano group, an allyl group or a propargyl group.]

[In Formula (2), R ¹ is an alkyl group having 1 to 8 carbon atoms, an aryl group, or an aromatic heterocyclic group.]

The group represented by R ¹ is an alkyl group having 1 to 8 carbon atoms, an aryl group or an aromatic heterocyclic group, and is specifically as follows.

Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, ox A linear or branched alkyl group, such as a tyl group, and cyclic alkyl groups, such as a cyclohexyl group, are mentioned. Preferably, it is a C1-C4 linear or branched alkyl group, More preferably, it is a methyl group or an ethyl group.

As an aryl group, a phenyl group, a naphthyl group, etc. are mentioned.

Examples of the aromatic heterocyclic group include a pyridyl group, a furyl group, and a thienyl group.

The groups represented by R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and each group is specifically as follows.

Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, ox A linear or branched alkyl group, such as a tyl group, Cyclic alkyl groups, such as a cyclohexyl group, etc. are mentioned. Preferably, it is a C1-C4 linear or branched alkyl group, More preferably, it is a methyl group or an ethyl group.

The group represented by R ⁴ is an alkyl group having 1 to 8 carbon atoms, an aryl group, a substituted aryl group, an aromatic heterocyclic group, an alkoxy group, an acyl group, an amide group, an oxycarbonyl group, a cyano group, an allyl group or a propargyl group, specifically as follows:

Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, ox A cyclic alkyl group, such as a linear or branched alkyl group, such as a tyl group, and a cyclohexyl group, etc. are mentioned. Preferably, it is a C1-C4 linear or branched alkyl group, More preferably, it is a methyl group or an ethyl group.

As an aryl group, a phenyl group, a naphthyl group, etc. are mentioned. Preferably, it is a phenyl group.

As a substituted aryl group, the phenyl group which has a substituent, the naphthyl group which has a substituent, etc. are mentioned. Examples of the substituent of the aryl group having a substituent include a halogen atom, a hydroxyl group, an alkoxy group, an amino group, a nitro group, a cyano group, and a carbonyl-containing group represented by -COR ⁴¹ (R ⁴¹ is an alkyl group having 1 to 8 carbon atoms). , an aryl group, an alkoxy group having 1 to 8 carbon atoms or an aryloxy group), a sulfonyl group, and a trifluoromethyl group. Moreover, it is good that these substituents are substituted 1 or 2 pieces.

Examples of the aromatic heterocyclic group include a pyridyl group, a furyl group, and a thienyl group.

The alkoxy group is preferably a group in which an alkyl group having 1 to 8 carbon atoms is bonded to an oxygen atom, for example, a methoxy group, ethoxy group, propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tet- A butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, etc. are mentioned.

As an acyl group, an acetyl group, a propionyl group, a benzoyl group, etc. are mentioned.

Examples of the amide group include -CONR ⁴²¹ R ⁴²² (R ⁴²¹ and R ⁴²² each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group).

The oxycarbonyl group is preferably a group represented by -COOR ⁴³ (R ⁴³ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group), for example, a carboxy group, a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, n -butoxycarbonyl group, sec-butoxycarbonyl group, tert-butoxycarbonyl group, n-pentoxycarbonyl group, phenoxycarbonyl group, etc. are mentioned. A methoxycarbonyl group and an ethoxycarbonyl group are mentioned as a preferable oxycarbonyl group.

As an allyl group, -CR ⁴⁴¹ R ⁴⁴² -CR ⁴⁴³ =CR ⁴⁴⁴ R ⁴⁴⁵ (R ⁴⁴¹ , R ⁴⁴² are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, R ⁴⁴³ , R ⁴⁴⁴ , R ⁴⁴⁵ are each independently to a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group, and each substituent may be connected in a cyclic structure).

Examples of the propargyl group include -CR ⁴⁵¹ R ⁴⁵² -C≡CR ⁴⁵³ (R ⁴⁵¹ and R ⁴⁵² are a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, R ⁴⁵³ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group, or silyl group).

The organic tellurium compound represented by Formula (1), specifically, (methyltelanylmethyl)benzene, (methyltelanylmethyl)naphthalene, ethyl-2-methyl-2-methyltelanyl-propionate, ethyl- 2-Methyl-2-n-butyltelanyl-propionate, (2-trimethylsiloxyethyl)-2-methyl-2-methyltelanyl-propionate, (2-hydroxyethyl)-2-methyl -2-methyltelanyl-propionate or (3-trimethylsilylpropargyl)-2-methyl-2-methyltelanyl-propionate, etc., International Publication No. 2004/14848, International Publication No. 2004/14962 All of the organic tellurium compounds described in International Publication No. 2004/072126, and International Publication No. 2004/096870 can be exemplified.

The organic ditelluride compound represented by Formula (2), specifically, dimethylditelluride, diethylditelluride, di-n-propylditelluride, diisopropylditelluride, dicyclopropylditelluride Ride, di-n-butylditelluride, di-s-butylditelluride, di-t-butylditelluride, dicyclobutylditelluride, diphenylditelluride, bis-(p-methoxyphenyl ) ditelluride, bis-(p-aminophenyl)ditelluride, bis-(p-nitrophenyl)ditelluride, bis-(p-cyanophenyl)ditelluride, bis-(p-sulfonylphenyl) ) ditelluride, dinaphthyl ditelluride or dipyridyl ditelluride, and the like can be exemplified.

The azo polymerization initiator can be used without particular limitation, as long as it is an azo polymerization initiator used in normal radical polymerization. For example, 2,2'-azobis(isobutyronitrile) (AIBN), 2,2'-azobis(2-methylbutyronitrile) (AMBN), 2,2'-azobis(2,4) -dimethylvaleronitrile) (ADVN), 1,1'-azobis(1-cyclohexanecarbonitrile) (ACHN), dimethyl-2,2'-azobisisobutyrate (MAIB), 4,4'-azo Bis(4-cyanovaleric acid) (ACVA), 1,1'-azobis(1-acetoxy-1-phenylethane), 2,2'-azobis(2-methylbutylamide), 2,2 '-Azobis (4-methoxy-2,4-dimethylvaleronitrile) (V-70), 2,2'-azobis (2-methylamidinopropane) dihydrochloride, 2,2'-azobis [2-(2-imidazolin-2-yl)propane], 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2'-azobis( 2,4,4-trimethylpentane), 2-cyano-2-propylazoformamide, 2,2'-azobis(N-butyl-2-methylpropionamide), or 2,2'-azobis (N-cyclohexyl-2-methylpropionamide) etc. can be illustrated.

In the polymerization step, in a container substituted with an inert gas, the vinyl monomer and the organic tellurium compound of formula (1) are subjected to azo polymerization for the purpose of promoting a reaction, controlling molecular weight and molecular weight distribution depending on the type of vinyl monomer. The initiator and/or the organic ditelluride compound of formula (2) are mixed. At this time, nitrogen, argon, helium, etc. are mentioned as an inert gas. Preferably, argon and nitrogen are preferred.

In the polymerization method of the above (a), (b), (c) and (d), the amount of the vinyl monomer used may be appropriately adjusted depending on the physical properties, molecular weight, etc. of the target copolymer, usually, Formula (1) It is preferable to set the vinyl monomer to 200 mol to 30000 mol with respect to 1 mol of the organic tellurium compound. In addition, the molecular weight of the target copolymer can also be increased by increasing the usage-amount of a vinyl monomer with respect to 1 mol of organic tellurium compound of Formula (1).

In the polymerization method of (b), when the organic tellurium compound of Formula (1) and an azo polymerization initiator are used together, the amount of the azo polymerization initiator used is usually 1 mol of the organic tellurium compound of Formula (1) It is preferable to set the azo polymerization initiator to 0.01 mol to 10 mol.

In the polymerization method of said (c), when the organic tellurium compound of Formula (1) and the organic ditelluride compound of Formula (2) are used together, the usage-amount of the organic ditelluride compound of Formula (2) is usually , It is preferable to make the organic ditelluride compound of Formula (2) into 0.01 mol - 100 mol with respect to 1 mol of organic tellurium compound of Formula (1).

In the polymerization method of (d), when the organic tellurium compound of Formula (1), the organic ditelluride compound of Formula (2), and an azo polymerization initiator are used together, the amount of the azo polymerization initiator to be used is usually, It is preferable to set the azo polymerization initiator to 0.01 mol to 100 mol with respect to a total of 1 mol of the organic tellurium compound of the formula (1) and the organic ditelluride compound of the formula (2).

Although the polymerization reaction can also be carried out without a solvent, an aprotic solvent or a protic solvent generally used in radical polymerization may be used and the mixture may be stirred. The aprotic solvent that can be used includes, for example, benzene, toluene, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetone, 2-butanone (methylethyl ketone), dioxane, Propylene glycol monomethyl ether acetate, chloroform, carbon tetrachloride, tetrahydrofuran (THF), ethyl acetate, propylene glycol monomethyl ether acetate, or trifluoromethylbenzene can be exemplified. Further, as the protic solvent, for example, water, methanol, ethanol, isopropanol, n-butanol, ethyl cellosolve, butyl cellosolve, 1-methoxy-2-propanol or diacetone alcohol, hexafluoroisopropanol etc. can be exemplified.

The amount of the solvent used may be appropriately adjusted, for example, 0.01 ml or more with respect to 1 g of the vinyl monomer, more preferably 0.05 ml or more, still more preferably 0.1 ml or more, and preferably 50 ml or less, More preferably, it is 10 ml or less, More preferably, it is 1 ml or less.

Next, the mixture is stirred. The reaction temperature and the reaction time may be appropriately adjusted depending on the molecular weight or molecular weight distribution of the copolymer obtained, and the mixture is usually stirred at 0°C to 150°C for 1 minute to 100 hours. The TERP method can obtain a high yield and precise molecular weight distribution even at a low polymerization temperature and a short polymerization time. At this time, although the pressure is normally performed at normal pressure, you may pressurize or pressure-reduce.

After completion of the polymerization reaction, the obtained reaction mixture is subjected to removal of the used solvent and residual vinyl monomer by a normal isolation and purification means, and the target copolymer can be isolated and purified. In addition, as long as the physical properties of the pressure-sensitive adhesive composition are not affected, the reaction mixture may be used for the pressure-sensitive adhesive composition as it is.

The growth terminal of the copolymer obtained by the polymerization reaction is in the form of -TeR ¹ (wherein R ¹ is the same as above), and the activity is lost by operation in air after the polymerization reaction is completed, but the tellurium atoms remain There are cases. Since the copolymer in which the tellurium atoms remain at the terminal is colored or has poor thermal stability, it is preferable to remove the tellurium atoms.

Examples of the method for removing the tellurium atom include a radical reduction method using tributylstannane or a thiol compound; adsorption with activated carbon, silica gel, activated alumina, activated clay, molecular sieves, and polymer adsorbents; a method of adsorbing a metal with an ion exchange resin or the like; A liquid-liquid that removes residual tellurium compounds by adding hydrogen peroxide or a peroxide such as benzoyl peroxide, or blowing air or oxygen into the system to oxidatively decompose the tellurium atoms at the ends of the copolymer, washing with water or combining an appropriate solvent extraction method or solid-liquid extraction method; A purification method in a solution state such as limit filtration that extracts and removes only a specific molecular weight or less can be used, and a combination of these methods can also be used. Moreover, in the copolymer produced by the TERP method, the metal compound derived from a chain transfer agent may remain|survive as an impurity (more than 0 ppm). It is preferable to set it as 1000 ppm or less, as for content of the tellurium in the copolymer produced by the TERP method, it is more preferable to set it as 400 ppm or less, It is further more preferable to set it as 200 ppm or less.

((B) isocyanate-based crosslinking agent)

The said adhesive composition contains (B) an isocyanate type crosslinking agent. The isocyanate-based crosslinking agent is a compound having two or more isocyanate groups (including isocyanate regenerated functional groups in which the isocyanate group is temporarily protected by a blocking agent or quantification or the like) in one molecule. The said (B) isocyanate type crosslinking agent may be used independently and may use 2 or more types together.

Examples of the isocyanate-based crosslinking agent include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate.

More specifically, For example, Lower aliphatic polyisocyanate, such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate; aromatic diisocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, and polymethylene polyphenyl isocyanate; Isocyanate adducts, such as a trimethylol propane/tolylene diisocyanate trimer adduct, a trimethylol propane/hexamethylene diisocyanate trimer adduct, and the isocyanurate body of hexamethylene diisocyanate; trimethylolpropane adduct of xylylene diisocyanate; trimethylolpropane adduct of hexamethylene diisocyanate; polyether polyisocyanate, polyester polyisocyanate, and polyisocyanate polyfunctionalized by an adduct of these and various polyols, an isocyanurate bond, a biuret bond, an allophanate bond, etc.; 1 type or 2 or more types selected from etc. can be used. Among these, it is preferable to use an aliphatic isocyanate because the reaction rate is fast.

As for content of the (B) isocyanate type crosslinking agent in the said adhesive composition, 0.01 mass part or more is preferable with respect to 100 mass parts of said (A) copolymers, More preferably, it is 0.1 mass part or more, More preferably, 1 mass It is more than a part, 20 mass parts or less are preferable, More preferably, it is 15 mass parts or less, More preferably, it is 10 mass parts or less. When the content of the crosslinking agent is small, the cohesive force is insufficient, and when the content of the crosslinking agent is too large, the crosslinking density becomes too high and the adhesive force is lowered, which is undesirable.

In the pressure-sensitive adhesive composition, the molar ratio (molar amount of isocyanate group/molar amount of reactive functional group) of the isocyanate group of the (B) isocyanate-based crosslinking agent to the reactive functional group of the (A) copolymer is preferably 0.001 or more, more preferably is 0.01 or more, more preferably 0.1 or more, preferably 10 or less, more preferably 5 or less, still more preferably 2 or less.

((C) metal chelate compound)

The said adhesive composition contains (C) a metal chelate compound. Thereby, in formation of an adhesive composition, time of curing is short, and it becomes possible to suppress heavy peeling of the obtained adhesive film. The (C) metal chelate compound is a complex in which a ligand having two or more coordination atoms forms a ring and binds to a central metal. The said (C) metal chelate compound may be used independently and may use 2 or more types together.

As the metal constituting the (C) metal chelate compound, for example, one selected from aluminum, zirconium, titanium, zinc, barium, calcium, copper, strontium, chromium, cobalt, iron, indium, magnesium, manganese and nickel species or two or more metal atoms. Among these, at least one kind of metal atom selected from aluminum, zirconium, titanium and zinc is suitable. Moreover, it is preferable that the said (C) metal chelate compound does not contain tin as a structural metal.

In the (C) metal chelate compound, the coordination number may be selected within an appropriate range in consideration of the type of metal atom used or the intended effect, and is not particularly limited. In the metal chelate compound (C), the coordination number of the metal atom is 3 to 20, preferably 4 to 16. In the present invention, the "coordination number" refers to the number of coordination bonds formed between the metal atom and the ligand.

Examples of the ligand (chelating agent) constituting the metal chelate compound (C) include polyaminocarboxylic acids, oxycarboxylic acids, and condensed phosphates. It is preferable that the said (C) metal chelate compound contains the ligand represented by following formula (3).

[In the formula, R ¹¹ and R ¹² each independently represent hydrogen, an alkyl group or an alkoxy group.]

The alkyl group represented by R ¹¹ or R ¹² is preferably an alkyl group having 1 to 8 carbon atoms. Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, ox A cyclic alkyl group, such as a linear or branched alkyl group, such as a tyl group, and a cyclohexyl group, etc. are mentioned. Preferably, it is a C1-C4 linear or branched alkyl group, More preferably, it is a methyl group or an ethyl group.

The alkoxy group represented by R ¹¹ or R ¹² is preferably a group in which an alkyl group having 1 to 8 carbon atoms is bonded to an oxygen atom, for example, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and n-butoxy group. group, sec-butoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, and the like.

Examples of the ligand contained in the metal chelate compound (C) include an acetylacetonate-based ligand, an acetoacetate-based ligand, an acetonate-based ligand, a lactate-based ligand, a carboxylic acid-based ligand, a citrate-based ligand, and a glycol-based ligand. A ligand etc. are mentioned. Specific examples include acetylacetonate, alkylacetoacetate, alkylenediaminetetraacetate, diisoalkoxybisalkylacetoacetate, diisopropoxybisalkylacetoacetate, di-n-alkoxy-bisalkyl-acetoacetate, Hydroxyalkylenediamine triacetate etc. are mentioned.

Specific examples of the metal chelate compound (C) include zirconium tetraacetylacetonate, zirconium tributoxy monoacetylacetonate, zirconium monobutoxyacetylacetonate bis(ethylacetoacetate), zirconium dibutoxybis(ethylacetoacetate), etc. of zirconium chelate compounds; titanium chelate compounds such as titanium ethylacetoacetate, titaniumdiisopropoxybis(acetylacetonate), titaniumtetraacetylacetonate, and titaniumdiisopropoxybis(ethylacetoacetate); aluminum chelate compounds such as aluminum tris(acetylacetonate), aluminum bisethylacetoacetate monoacetylacetonate, aluminum tris(ethylacetoacetate), aluminum ethylacetoacetate diisopropylate, and aluminum alkylacetoacetate diisopropylate; zinc chelate compounds such as zinc (II) bisacetylacetonate monohydrate; barium chelate compounds such as bis(acetylacetonate)diaquabarium(II) and calcium chelate compounds such as bis(acetylacetonate)diaquacalcium(II); copper chelate compounds such as copper (II) bisacetylacetonate; strontium chelate compounds such as bis(acetylacetonate)diaquastrontium(II); chromium chelate compounds such as chromium tris (acetylacetonate); cobalt chelate compounds such as cobalt(III)tris(acetylacetonate) and bis(acetylacetonate)diaquacobalt(II); iron chelate compounds such as iron(III)tris(acetylacetonate) and bis(acetylacetonate)diaquairon(II); indium chelate compounds such as indium tris(acetylacetonate); magnesium chelate compounds such as bis(acetylacetonate)diaquamagnesium(II); manganese chelate compounds such as bis(acetylacetonate)diaquamanganese(II); Nickel chelate compounds, such as nickel (II) bisacetylacetonate dihydrate, etc. are mentioned. Among these, a zirconium chelate compound and a titanium chelate compound are preferable.

As for content of the (C) metal chelate compound in the adhesive composition of this invention, 0.01 mass part or more is preferable with respect to 100 mass parts of said (A) copolymers, More preferably, 0.02 mass part or more, More preferably is 0.04 parts by mass or more, preferably 0.5 parts by mass or less, more preferably 0.4 parts by mass or less, still more preferably 0.3 parts by mass or less. (C) By making content of a metal chelate compound into the said range, it becomes possible to acquire the outstanding crosslinking acceleration|stimulation effect and the heavy peeling suppression effect.

Here, when the metal compound derived from the chain transfer agent used by the living radical polymerization is contained in an adhesive composition, it is thought that the said metal compound will act|act with a to-be-adhered body and it will be easy to produce heavy peeling. In the adhesive composition of this invention, it becomes possible to suppress heavy peeling by containing the said (C) metal chelate compound. The metal compound derived from the chain transfer agent varies depending on the living radical polymerization method, for example, a tellurium compound in the case of the TERP method, and a copper compound, a ruthenium compound, a nickel compound, an iron compound in the case of the ATRP method. .

When the metal compound derived from a chain transfer agent is contained in the said (A) copolymer, content of the (C) metal chelate compound in an adhesive composition is the metal of the metal compound derived from the chain transfer agent contained in (A) copolymer. 2 mass parts or more are preferable with respect to conversion 1 mass part, More preferably, it is 2.5 mass parts or more, More preferably, it is 4 mass parts or more, 40 mass parts or less are preferable, More preferably, it is 35 mass parts or less. , More preferably, it is 30 mass parts or less. Heavy peeling can be suppressed by adjusting the mass ratio of the metal compound derived from a chain transfer agent, and (C) metal chelate compound.

The adhesive composition of this invention can accelerate|stimulate reaction of the reactive functional group which (A) copolymer has and (B) an isocyanate type crosslinking agent by mix|blending the said (C) metal chelate compound. Therefore, the adhesive composition of this invention can shorten the curing period at the time of forming an adhesive bond layer, even if it does not mix|blend an organotin compound. Therefore, the content rate of the organotin compound in the adhesive composition of this invention is 3 mass % or less, More preferably, it is 1 mass % or less, More preferably, it is 0.5 mass % or less. Moreover, it is preferable that the adhesive composition of this invention does not contain an organotin compound. The organotin compound is used as a crosslinking accelerator, and examples thereof include dibutyltin laurate and dibutyltin dioctylate.

(Other additives)

In the adhesive composition of this invention, other additives other than the said (A) copolymer, (B) an isocyanate type crosslinking agent, and (C) a metal chelate compound can be mix|blended and used. As another additive, the following are mentioned, for example.

(D) A crosslinking retarder can be mix|blended and used with the said adhesive composition as needed. Said (D) crosslinking retarder is a compound which can suppress the excessive viscosity raise of an adhesive composition by blocking the isocyanate group which a crosslinking agent has in the adhesive composition containing an isocyanate type crosslinking agent. (D) The type of the crosslinking retarder is not particularly limited, and for example, β- such as acetylacetone, hexane-2,4-dione, heptane-2,4-dione, and octane-2,4-dione diketones; β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, and stearyl acetoacetate; Benzoylacetone and the like can be used. As the crosslinking retarder (D), those that can act as a chelating agent are preferable, and β-diketones and β-ketoesters are preferable.

As for content of the (D) crosslinking retarder which can be mix|blended with an adhesive composition, 1 mass part or more is preferable with respect to 100 mass parts of (A) copolymer, More preferably, it is 2 mass parts or more, More preferably, 3 It is more than a mass part, 40 mass parts or less are preferable, More preferably, it is 30 mass parts or less, More preferably, it is 15 mass parts or less. By adjusting the content of the (D) crosslinking retarder to the above range, after blending the (B) isocyanate-based crosslinking agent in the pressure-sensitive adhesive composition, excessive increase in viscosity or gelation of the pressure-sensitive adhesive composition is suppressed, and storage stability of the pressure-sensitive adhesive composition ( pot life) can be extended.

In addition, when a compound acting as a chelating agent is used as the (D) crosslinking retarder, (A) the metal component of the metal compound derived from the chain transfer agent contained in the copolymer and (C) the metal component in the metal chelate compound. The mass ratio (chelate component/metal component) of the total of the chelating agent (ligand) component and (D) crosslinking retarder in the (C) metal chelate to the total is preferably 100 or more, more preferably 150 or more, further Preferably it is 200 or more, 1000 or less are preferable, More preferably, it is 900 or less.

A silane coupling agent can be mix|blended and used with the adhesive composition of this invention as needed. The silane coupling agent is not particularly limited, but for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2 Epoxy group-containing silane coupling agents, such as -(3,4 epoxycyclohexyl) ethyl trimethoxysilane; 3-Aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N an amino group-containing silane coupling agent such as -phenyl-γ-aminopropyltrimethoxysilane; (meth)acryl group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane; Isocyanate group containing silane coupling agents, such as 3-isocyanate propyl triethoxysilane, etc. are mentioned.

It is preferable that content of the silane coupling agent which can be mix|blended with an adhesive composition is 1 mass part or less with respect to 100 mass parts of (A) copolymer, More preferably, it is 0.01 mass part - 1 mass part, More preferably, it is 0.02 mass parts to 0.6 parts by mass. By adjusting content of the said silane coupling agent to the said range, the water resistance in the interface in the case of applying to hydrophilic to-be-adhered bodies, such as glass of an adhesive layer, is mentioned.

(B) Crosslinking agents other than an isocyanate type crosslinking agent can be mix|blended and used with the adhesive composition of this invention as needed. (B) As a crosslinking agent other than an isocyanate type crosslinking agent, an epoxy type crosslinking agent etc. are mentioned, for example. The epoxy-based crosslinking agent refers to a polyfunctional epoxy compound having two or more epoxy groups in one molecule. Examples of the epoxy-based crosslinking agent include bisphenol A, epichlorohydrin-type epoxy resin, ethylene glycidyl ether, N,N,N',N'-tetraglycidyl-m-xylenediamine, diglycidyl Cydylaniline, diamine glycidylamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether , Ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, pentaeryth Ritol polyglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, diglycidyl adipic acid Diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris(2-hydroxyethyl)isocyanurate, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, etc. are mentioned. have.

It is preferable that content of the epoxy-type crosslinking agent which can be mix|blended with an adhesive composition is 0.01 mass parts - 5 mass parts with respect to 100 mass parts of (A) copolymer, It is more preferable that they are 0.01 mass parts - 4 mass parts, and 0.02 It is more preferable that they are mass parts - 3 mass parts. By adjusting the content of the epoxy-based crosslinking agent in the above range, it is possible to further improve cohesive force and heat resistance.

In the pressure-sensitive adhesive composition of the present invention, if necessary, a tackifying resin excluding the copolymer (A) can be blended and used. Examples of the tackifying resin include rosin-based resins such as rosin ester-based resins, terpene-based resins such as terpene phenol resins, and petroleum-based resins. Among them, rosin ester-based resins and terpene phenol resins are preferable.

The rosin ester resin is a rosin resin containing abietic acid as a main component, a disproportionated rosin resin and a hydrogenated rosin resin, and a dimer (polymerized rosin resin) of a resin acid such as abietic acid (polymerized rosin resin), etc., by esterification with alcohol. It is a resin obtained by When a part of the hydroxyl group of the alcohol used for esterification is contained in resin without being used for esterification, the hydroxyl value is adjusted. Examples of the alcohol include polyhydric alcohols such as ethylene glycol, glycerin, and pentaerythritol. In addition, the resin obtained by esterifying a rosin resin is a rosin ester resin; The esterified resin is a polymerization rosin ester resin. The terpene phenol resin is a resin obtained by polymerizing terpene in the presence of phenol.

It is preferable that content of the said tackifying resin which can be mix|blended with an adhesive composition is 5 mass parts - 40 mass parts with respect to 100 mass parts of (A) copolymer. By adjusting content of the said tackifying resin to the said range, the static load peelability with respect to the to-be-adhered body of an adhesive film can improve.

In the pressure-sensitive adhesive composition of the present invention, if necessary, dyes, pigments, pigments, optical brighteners, wetting agents, surface tension regulators, thickeners, mildew inhibitors, preservatives, oxygen absorbers, ultraviolet absorbers, near-infrared absorbers, water-soluble matting agents, antioxidants, A fragrance, a metal deactivator, a nucleating agent, an antistatic agent, an alkylating agent, a flame retardant, a lubricant, a processing aid, etc. may be mixed and used, and these are appropriately selected and used according to the purpose or purpose of the adhesive.

(Method for producing pressure-sensitive adhesive composition)

The said adhesive composition can be manufactured by mixing the said (A) copolymer, (B) an isocyanate type crosslinking agent, (C) a metal chelate compound, and the other additive used as needed. The said adhesive composition may contain the solvent derived from manufacture of (A) copolymer, or the solution diluted so that an appropriate solvent may be added and it may become a viscosity suitable for forming an adhesive layer.

Examples of the solvent include aliphatic hydrocarbons such as hexane and heptane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and ethylene chloride; ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, and cyclohexanone; esters such as ethyl acetate and butyl acetate; cellosolve solvents such as ethyl cellosolve; Glycol ether solvents, such as propylene glycol monomethyl ether, etc. are mentioned. These solvents may be used individually by 1 type, and may mix and use 2 or more types.

The amount of the solvent used may be appropriately adjusted so that the pressure-sensitive adhesive composition has a viscosity suitable for coating, and there is no particular limitation.

(Use of adhesive composition)

The use of the pressure-sensitive adhesive composition is not particularly limited, and it can be used in a wide range of applications, and in particular, it is preferably used for optical applications such as production of optical products and optical members.

The optical product refers to a product in which optical properties (for example, polarization, light refraction, light scattering, light reflectivity, light transmittance, light absorption, light diffraction, optical rotation, visibility, etc.) are used in the product. . Examples of the optical product include display devices such as a liquid crystal display device, an organic EL (electroluminescence) display device, a PDP (plasma display panel), electronic paper, an input device such as a touch panel, or these display devices and a device in which an input device is appropriately combined with each other.

The said optical member means the member which has the said optical characteristic. As said optical member, the member which comprises apparatuses (optical apparatus), such as the said display apparatus (image display apparatus), the said input apparatus, or the member used for these apparatuses is mentioned, for example. Examples of the optical member include a polarizing plate, a wave plate, a retardation plate, an optical compensation film, a brightness enhancing film, a light guide plate, a reflective film, an antireflection film, a transparent conductive film (ITO film), a design film, a decorative film, a surface protection plate, and a prism, a lens, a color filter, a transparent substrate, and a member on which these are laminated (these may be collectively referred to as an "optical film"), and the like. In addition, the above "plate" and "film" shall include forms such as plate, film, and sheet, respectively, and, for example, "polarizing film" includes "polarizing plate" and "polarizing sheet" make it as Moreover, in the "optical member" in this invention, as mentioned above, the member (designer) which takes the role of decoration and protection, maintaining the visibility of the display part in a display device or an input device, and the outstanding external appearance. film, decorative film, surface protection film, etc.) shall also be included.

Although it does not specifically limit as a material which comprises the said optical member, For example, glass, an acrylic resin, a polycarbonate, a polyethylene terephthalate, a metal (metal oxide is included), etc. are mentioned.

<2. Adhesive film>

The adhesive film of this invention has a base film and the adhesive layer formed with the said adhesive composition. The pressure-sensitive adhesive layer is formed on at least one side or at least a part of the base film. In addition, in this invention, a "film" shall also include a tape and a sheet|seat.

The thickness of the base film is not particularly limited and is appropriately selected. Usually, 10 μm or more is preferable, more preferably 20 μm or more, 250 μm or less is preferable, and more preferably 200 μm or less.

As said base film, it can select and use suitably according to the use of an adhesion film, For example, when using an adhesion film for an optical use, it is preferable that it is a transparent base film. A transparent base material means a transparent base material. Examples of the transparent base film include polyester-based resins such as polyethylene terephthalate (PET); acrylic resins such as polymethyl methacrylate (PMMA); and films made of plastic materials such as polycarbonate, triacetyl cellulose (TAC), polysulfone, polyarylate, polyimide, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, and ethylene-propylene copolymer. The above plastic materials may be used alone or in combination of two or more. Among these, PET is preferable at the point excellent in mechanical strength and dimensional stability. Moreover, TAC is preferable at the point in which the retardation in a film plane is very small. That is, as said transparent base film, a PET film (particularly, the PET film biaxially stretched) and a TAC film are preferable.

Although the total light transmittance (JIS K7361-1 (1997)) in the visible light wavelength region of the said transparent base film is not specifically limited, It is preferable that it is 85 % or more. Since transparency is excellent by making a total light transmittance into 85 % or more, it becomes difficult to exert a bad influence on the visibility of the display part of an optical product, display quality, and the external appearance of an optical product.

The said base film can be surface-treated by the oxidation method, the unevenness|corrugation method, etc. on one side or both surfaces as desired for the purpose of improving adhesiveness with the layer formed on the surface. Examples of the oxidation method include corona discharge treatment, plasma treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone and ultraviolet irradiation treatment, and the like. As the said unevenness|corrugation reducing method, the sandblasting method, the solvent treatment method, etc. are mentioned. Although these surface treatment methods are suitably selected according to the kind of base film, in general, a corona discharge treatment method is used preferably from points, such as an effect and operability. Moreover, what gave the primer process to single side|surface or both surfaces as said base film can be used.

What is necessary is just to adjust the thickness of the said adhesive layer suitably according to the use of an adhesive film. For example, in the case of 0.1 micrometer - 20 micrometers, and OCA use (strong adhesion), 10 micrometers - 350 micrometers are preferable in a protective film use (non-adhesion).

The gel fraction of the pressure-sensitive adhesive layer is preferably 30% to 100%, more preferably 40% to 100%, still more preferably 50% to 100%, and 80% to 100% from the viewpoint of durability and adhesive strength. % is particularly preferred. When the gel fraction is too low, it is easy to generate insufficient durability due to insufficient cohesive force and paste residue at the time of peeling. A gel fraction is controllable with the compounding quantity of the crosslinking agent in an adhesive composition, crosslinking process temperature, and crosslinking process time.

It does not specifically limit as a formation method of the said adhesive layer, For example, the method of the following (1) and (2) is mentioned.

(1) The method of apply|coating an adhesive composition to the single side|surface or both surfaces of a base film using various coating apparatuses, drying and removing a solvent, and curing as needed.

(2) The pressure-sensitive adhesive composition is applied to the release surface of the release film whose surface has been subjected to a release treatment using various coating devices, the solvent is removed by drying and curing, if necessary, and then on one or both sides of the base film how to fight.

Examples of the coating device include a reverse roll coater, a gravure coater, a forward roll coater, a knife coater, a wire bar coater, a doctor blade coater, a slot die coater, a curtain coater, and a dip coater.

The drying temperature at the time of drying and removing the said solvent becomes like this. Preferably it is 40 degreeC - 200 degreeC, More preferably, it is 60 degreeC - 180 degreeC. Drying time becomes like this. Preferably it is 5 second - 20 minutes, More preferably, they are 10 second - 10 minutes. Examples of the drying means include hot air, near-infrared rays, infrared rays, and high-frequency waves. Moreover, as conditions of the said curing, about 3 days - about 7 days at 23 degreeC are mentioned, for example.

The said adhesive film may have a peeling film (separator) on the surface of an adhesive layer until it is used. Without using a separate release film, a release layer is formed on the surface opposite to the pressure-sensitive adhesive layer lamination surface of the base film, and the surface of the release layer is wound in a roll shape so that the exposed surface side of the pressure-sensitive adhesive layer is in contact, or stacked It may be formed by laminating in a mold. A peeling film is used as a protective material of an adhesive layer, and when affixing the adhesive film of this invention to a to-be-adhered body, it peels.

As said release film, what apply|coated release agents, such as a silicone resin, to paper, such as glassine paper, coated paper, and laminated paper, and various plastic films, etc. are mentioned, for example. As a plastic film used for the said peeling film, what was mentioned as a base film can be used suitably. Although there is no restriction|limiting in particular as thickness of a peeling film, Usually, they are 10 micrometers - 150 micrometers.

The adhesive film of this invention is good also as a functional adhesive film which has an adhesive layer in one surface of a base film, and has a functional layer in the other surface. As said functional layer, the coating layer which has functions, such as abrasion resistance, antireflection property, anti-glare property (anti-glare property), antifouling property, anti-glare property, chemical resistance, and glass scattering prevention property, is mentioned. A well-known method can be employ|adopted for the method of forming the said functional layer. Moreover, the layer for exhibiting functions, such as anti-glare property, antifouling property, anti-fouling property, and chemical-resistance, may be laminated|stacked as said functional layer. For example, by setting the hard coat layer as a lamination structure of a layer excellent in abrasion resistance and a layer excellent in antiglare property, a hard coat layer excellent in both characteristics of abrasion resistance and antiglare property can be obtained.

<3. Image display device>

The image display apparatus of this invention is provided with the said adhesive film, It is characterized by the above-mentioned. Examples of the image display device include a liquid crystal display, an organic EL (electroluminescence) display, a plasma display, and electronic paper.

Examples of the adhesive film include an optical film, and specifically, a polarizing plate, a wave plate, a retardation plate, an optical compensation film, a brightness enhancing film, a light guide plate, a reflective film, an antireflection film, a transparent conductive film (ITO film), a design A film, a decorative film, a surface protection plate, etc. are mentioned.

The image display apparatus which has the adhesion film of this invention can be obtained by manufacturing the said display apparatus using the optical member which has the adhesion film of this invention, or the adhesion film of this invention.

[Example]

Hereinafter, the present invention will be described in more detail based on specific examples. The present invention is not limited to the following examples at all, and can be implemented with appropriate changes within a range that does not change the gist of the present invention. In addition, the polymerization rate of the copolymer, weight average molecular weight (Mw), molecular weight distribution (PDI), solid content, viscosity, and adhesive strength of the pressure-sensitive adhesive composition, adhesive strength after heating, glue residue, peeling force to the peeling film, gel fraction, It was evaluated according to the following method.

In addition, the meaning of the abbreviation is as follows.

BTEE: Ethyl-2-methyl-2-n-butyltelanyl-propionate

V-70: 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile)

MA: Methyl acrylate

BA: Butyl acrylate

2-EHA: 2-ethylhexyl acrylate

LA: Lauryl acrylate

CHA: Cyclohexyl acrylate

4-HBA: 4-hydroxybutyl acrylate

HEA: Hydroxyethyl acrylate

AcOEt: ethyl acetate

(Polymerization rate)

¹ H-NMR was measured (solvent: CDCl ₃ , internal standard: trimethylsilane (TMS)) using a nuclear magnetic resonance (NMR) measuring apparatus (manufactured by Bruker Biospin, model name: AVANCE500 (frequency 500 MHz)). . About the obtained NMR spectrum, the integral ratio of the peak of the vinyl group derived from a monomer and the ester side chain derived from a polymer was calculated|required, and the polymerization rate of the monomer was computed.

(weight average molecular weight (Mw) and molecular weight distribution (PDI))

It calculated|required by gel permeation chromatography (GPC) using the high performance liquid chromatography (Tosoh Corporation make, model name: HLC-8320GPC). For the column, two TSKgel Super Multipore HZ-H (manufactured by Tosoh Corporation), a tetrahydrofuran solution for the mobile phase, and a differential refractometer were used for the detector. Measurement conditions were a column temperature of 40°C, a sample concentration of 10 mg/mL, a sample injection amount of 10 µm, and a flow rate of 0.2 mL/min. A calibration curve (calibration curve) was prepared using polystyrene (molecular weights 2,890,000, 1,090,000, 775,000, 427,000, 190,000, 96,400, 37,900, 10,200, 2,630, 440) as a standard material, weight average molecular weight (Mw), number average molecular weight (Mn) ) was measured. The molecular weight distribution (PDI=Mw/Mn) was calculated from this measurement.

(solid content)

A copolymer solution having a mass of W1 (about 1.0 g) was weighed in an aluminum cup (mass W0) and dried under reduced pressure at 130°C for 1 hour. The mass (W2) of the aluminum cup containing the dried copolymer was measured, and solid content was computed from the following formula|equation.

Solid content (% by mass) = [(W2-W0)/W1] × 100

(viscosity)

Using a B-type viscometer (trade name: TVB-15, manufactured by Dongho Industries Co., Ltd.), the viscosity was measured at 25° C. and the number of rotations of the rotor at 60 rpm using an M3 rotor.

<Production of copolymer>

(Synthesis Example 1)

In a flask equipped with an argon gas introduction tube and a stirrer, 2-EHA (475.0 g), 4-HBA (25.0 g), V-70 (45.7 mg), and AcOEt (377.2 g) were injected, and after argon substitution, BTEE (111.1 mg) was added, and it was made to react at 33 degreeC for 20 hours, and it superposed|polymerized. The polymerization rate was 88.5%.

After completion of the reaction, AcOEt was added to the reaction solution to obtain a solution of copolymer A. The obtained copolymer A had a Mw of 974,000, a PDI of 2.34, and a Tg of -69° C., the content of 4-HBA in the copolymer was 5% by mass, and the amount of reactive functional groups in 100 g of the copolymer was 0.03 mol. The copolymer solution had a solid content of 22.3 mass% and a viscosity of 3,881 mPa·s. In addition, the content rate of each structural unit and the amount of reactive functional groups in a copolymer were computed from the injection|pouring ratio of the vinyl monomer used for the polymerization reaction.

After drying the solution of copolymer A, an incineration treatment was performed, and by inductively coupled plasma mass spectrometry (ICP/MS), the amount of the tellurium compound relative to the solid content of the solution of copolymer A was 106 ppm in terms of metal. confirmed that.

(Synthesis Example 2)

BA (475 g), 4-HBA (25 g), V-70 (61.7 mg), and AcOEt (377.2 g) were injected into a flask equipped with an argon gas introduction tube and a stirrer, and after argon substitution, BTEE (200.9 mg) was added and reacted at 33° C. for 30 hours, followed by polymerization. The polymerization rate was 86.2%.

After completion of the reaction, AcOEt was added to the reaction solution to obtain a solution of copolymer B. The obtained copolymer B had a Mw of 701,000, a PDI of 1.63, and a Tg of -53° C., the content of 4-HBA in the copolymer was 5% by mass, and the amount of reactive functional groups in 100 g of the copolymer was 0.03 mol. The copolymer solution had a solid content of 19.8 mass% and a viscosity of 2,364 mPa·s. In addition, the content rate of each structural unit and the amount of reactive functional groups in a copolymer were computed from the injection|pouring ratio of the vinyl monomer used for the polymerization reaction.

After drying the solution of copolymer B, it was incinerated, and by inductively coupled plasma mass spectrometry (ICP/MS), it was confirmed that the amount of the tellurium compound with respect to the solid content of the solution of copolymer B was 197 ppm in terms of metal.

(Synthesis Example 3)

BA (300 g), 2-EHA (75 g), CHA (100 g), HEA (25 g), V-70 (38.8 mg), and AcOEt (377.2 g) were injected into a flask equipped with an argon gas inlet tube and agitator. , After argon substitution, BTEE (111.0 mg) was added, and reaction was conducted at 33°C for 22 hours, followed by polymerization. The polymerization rate was 81.1%.

After completion of the reaction, AcOEt was added to the reaction solution to obtain a solution of copolymer C. The obtained copolymer C had a Mw of 941,000, a PDI of 1.95, and a Tg of -44° C., the content of HEA in the copolymer was 5% by mass, and the amount of reactive functional groups in 100 g of the copolymer was 0.04 mol. The copolymer solution had a solid content of 17.6% by mass and a viscosity of 4368 mPa·s. In addition, the content rate of each structural unit and the amount of reactive functional groups in a copolymer were computed from the injection|pouring ratio of the vinyl monomer used for the polymerization reaction.

After drying the solution of copolymer C, it was incinerated, and by inductively coupled plasma mass spectrometry (ICP/MS), it was confirmed that the amount of the tellurium compound with respect to the solid content of the solution of copolymer C was 128 ppm in terms of metal.

(Synthesis Example 4)

MA (50 g), 2-EHA (350 g), LA (75 g), 4-HBA (25 g), V-70 (57.1 mg), AcOEt (333.3 g) were added to a flask equipped with an argon gas inlet tube and stirrer. After injection, argon substitution, BTEE (299.87 mg) was added, and reaction was carried out at 33°C for 21 hours, followed by polymerization. The polymerization rate was 89.4%.

After completion of the reaction, AcOEt was added to the reaction solution to obtain a solution of copolymer C. The obtained copolymer D had a Mw of 478,000, a PDI of 1.78, and a Tg of -56°C, the content of 4-HBA in the copolymer was 5% by mass, and the amount of reactive functional groups in 100 g of the copolymer was 0.03 mol. The copolymer solution had a solid content of 42.4 mass% and a viscosity of 7070 mPa·s. In addition, the content rate of each structural unit and the amount of reactive functional groups in a copolymer were computed from the injection|pouring ratio of the vinyl monomer used for the polymerization reaction.

After drying the solution of copolymer D, it was incinerated, and it was confirmed by inductively coupled plasma mass spectrometry (ICP/MS) that the amount of the tellurium compound with respect to the solid content of the solution of copolymer D was 285 ppm in terms of metal.

<Preparation of the pressure-sensitive adhesive composition>

(Adhesive composition No. 1)

With respect to 448.4 parts by mass of the solution of the copolymer A obtained in Synthesis Example 1 (100 parts by mass of the copolymer component, 348.4 parts by mass of AcOEt), 6.31 parts by mass of an isocyanate compound, 0.08 parts by mass of a zirconium chelate compound, and 13.9 parts by mass of acetylacetone 196.6 mass parts of AcOEt and AcOEt were added, stirred, and adhesive composition No. 1 was obtained.

(Adhesive composition No.2-28)

Except having changed the formulation as described in Tables 2 - 4, it carried out similarly to adhesive composition No. 1, and produced adhesive composition No. 2-28. In addition, the amount of solvent in Tables 2 - 4 is the total amount of AcOEt contained in the solution of a copolymer, and AcOEt added at the time of preparation of an adhesive composition.

[Table 2]

[Table 3]

[Table 4]

<Production of adhesive film>

(Adhesive film No. 1)

On a polyethylene terephthalate (PET) film (thickness 125 micrometers), adhesive composition No. 1 was apply|coated so that the thickness after drying might be set to 7 micrometers. The PET film to which the adhesive composition was apply|coated was dried at 100 degreeC for 1 minute, and adhesive film No. 1 which has an adhesive layer was produced. A release film (thickness of 25 µm, manufactured by Toray Film Processing Co., Ltd., "Cerafil (registered trademark) WZ") was attached to the obtained pressure-sensitive adhesive layer, and cured by standing still at 23°C for 1 week.

(Adhesive film No.2-5)

Except having changed adhesive composition No.1 into adhesive composition No.2-5, it carried out similarly to adhesive film No.1, and produced adhesive film No.2-5.

(Adhesive film No.6)

On PET film (thickness 125 micrometers), adhesive composition No. 6 was apply|coated so that the thickness after drying might be set to 10 micrometers. The PET film to which the adhesive composition was apply|coated was dried at 100 degreeC for 2 minute(s), and the adhesive film which has an adhesive layer was produced. A release film (thickness of 25 µm, manufactured by Toray Film Processing Co., Ltd., "Cerafil (registered trademark) WZ") was attached to the obtained pressure-sensitive adhesive layer, and cured by standing still at 23°C for 1 week.

(Adhesive film No.7-19)

Except having changed adhesive composition No.6 into adhesive composition No.7-19, it carried out similarly to adhesive film No.6, and produced adhesive film No.7-19.

(Adhesive film No.20)

On PET film (50 micrometers in thickness), adhesive composition No. 20 was apply|coated so that the thickness after drying might be set to 10 micrometers. The PET film to which the adhesive composition was apply|coated was dried at 100 degreeC for 2 minute(s), and the adhesive film which has an adhesive layer was produced. A peeling film (thickness 25 µm, "HY-PS11", manufactured by Higashiyama Film Company) was affixed to the obtained pressure-sensitive adhesive layer, and was cured by standing still at 40°C for 3 days.

(Adhesive film No.21-28)

Except having changed adhesive composition No.20 into adhesive composition No.21-28, it carried out similarly to adhesive film No.20, and produced adhesive film No.21-28.

<Evaluation of the adhesive film>

(IR peak intensity ratio)

About the adhesive layer of adhesion film No. 1-5, the residual amount of the isocyanate group in the case of 3 hours of curing period and 7th day (1 week) progress was evaluated. The residual amount of the isocyanate group was evaluated by measuring the peak intensity of 2275 cm ^-1 which is the antisymmetric stretching IR peak of the isocyanate group. The measurement was performed by the total reflection method (ATR method) using a Fourier transform infrared spectrophotometer (FT-IR). In Table 5, the intensity|strength ratio with respect to the peak intensity in 3 hours after the curing period of adhesion film No. 5 was shown.

(adhesiveness)

The adhesive force of the adhesive film was measured based on the measuring method of the adhesive force of JIS Z0237 (2009) (Method 1: The test method which peels a tape and a sheet|seat at 180 degrees with respect to a stainless steel test plate). Specifically, a surface-cleaned adherend (stainless steel sheet (SUS304BA) Ra50 nm (JIS B 0601 (1994))) is crimped using a crimping device (mass of roller: 2 kg), and separated at 180° from the adherend. The adhesive force at the time of taking out was measured. The test temperature was 23 degreeC, and the peeling rate was 300 mm/min. The width of the adhesive film was 25 mm and the length was 300 mm. After the start of the measurement, the first measurement of the length of 25 mm was ignored, and the measured values of the adhesive force of the length of 50 mm removed from the test plate after that were averaged.

(Adhesive strength after heating)

It carried out similarly to the measurement of the said adhesive force, after crimping|bonding an adhesive film to a to-be-adhered body, it heated at 150 degreeC for 1 hour, and cooled in room temperature (23 degreeC) after that for 1 hour. After cooling, it carried out similarly to the measurement of the said adhesive force, and the adhesive force at the time of peeling off at 180 degrees was measured. In addition, the increase rate by heating of adhesive force was computed with the following formula.

Increase rate (%) = (adhesive force after heating/adhesive force without heating) x 100

(Adhesive glue residue after measuring adhesive force)

In the measurement of the adhesive force after heating, the adherend after peeling off the adhesive film was visually observed, and it was confirmed whether there was any glue residue on the adherend. A thing with no grass residue was evaluated as "○", and a thing with a grass residue was evaluated as "x".

(peel force)

The peeling force at the time of peeling a peeling film was measured based on the measuring method of peeling force of JIS Z0237 (2009) (Method 4: Test method which peels a peeling liner at 180 degrees with respect to the adhesive surface of a tape and a sheet|seat). Specifically, the adhesive film was fixed to the stainless steel plate with a double-sided adhesive tape, and the peeling force at the time of peeling off the peeling film at 180 degrees with respect to the adhesive film was measured. The test temperature was 23 degreeC, and the peeling rate was 300 mm/min. The width of the release film and the pressure-sensitive adhesive film was 25 mm and the length was 300 mm. After the start of the measurement, the first measured value of the length of 25 mm was ignored, and the measured values of the peel force of the length of 50 mm removed from the pressure-sensitive adhesive film after that were averaged.

(Peeling force after heating)

About adhesion film No. 1-5, the adhesion film with a peeling film was heated at 100 degreeC for 1 hour, and it cooled at 23 degreeC after that for 1 hour. About adhesion film No. 6-28, the adhesion film with a peeling film was heated at 150 degreeC for 1 hour, and it cooled in 23 degreeC after that for 1 hour. After cooling, it carried out similarly to the measurement of the said peeling force, and the peeling force at the time of peeling off at 180 degrees was measured. In addition, the increase rate by heating of peeling force was computed with the following formula.

Increase rate (%) = (Peel force after heating / Peel force without heating) x 100

(gel fraction)

The adhesive composition was apply|coated to the peeling film, and it was made to dry at 100 degreeC for 1 minute (Adhesive composition No. 1-5) or 100 degreeC for 2 minutes (Adhesive composition No. 6-28). Then, after leaving still at 23 degreeC for 1 week to cure, the adhesive layer formed on the peeling film was peeled.

The pressure-sensitive adhesive layer having a mass of W1 (about 0.10 g) was weighed with a stainless steel mesh (400 mesh) having a mass of W0, and immersed in ethyl acetate at 60°C for 24 hours. Then, the pressure-sensitive adhesive layer and the stainless steel mesh were taken out from ethyl acetate, dried at 23°C for 24 hours, and further dried under reduced pressure under conditions of 130°C for 1 hour. After drying, the weight W2 of the stainless steel wire mesh including the dried pressure-sensitive adhesive layer was measured, and the gel fraction was calculated from the following formula.

Gel fraction (mass %) = [(W2-W0)/W1] × 100

[Table 5]

[Table 6]

[Table 7]

[Table 8]

Isocyanate compound: The Asahi Kasei company make, Duranate (trademark) TPA-100

Zirconium chelate compound: The Matsumoto Fine Chemicals make, Orgatyx (trademark) ZC-150 (zirconium tetraacetylacetonate)

Titanium chelate compound: made by Matsumoto Fine Chemicals, Orgatyx (registered trademark) TC-750 (titanium diisopropoxybis (ethylacetoacetate))

Aluminum chelate compound: Kawaken Fine Chemicals, aluminum chelate A (aluminum tris (acetylacetonate))

Organotin compound: Nitto Kasei Co., Ltd. make, Neostan (registered trademark) U810 (dioctyl tin)

Amine compound: The Tokyo Kasei company make, 1, 4- diazabicyclo [2.2.2] octane

As shown in Table 5, when a zirconium chelate compound or a titanium chelate compound is used as a crosslinking promoter (adhesive composition No. 1, 2), even if it is 3 hours of curing period, IR peak intensity ratio becomes small. Therefore, it turns out that these chelate compounds have crosslinking acceleration|stimulation performance similarly to an organotin compound (adhesive composition No. 3). In addition, when an amine compound is used as a crosslinking accelerator (adhesive composition No. 4), the IR peak intensity ratio is 1.0 in a curing period of 3 hours. That is, it turns out that an amine compound does not have crosslinking acceleration|stimulation performance.

In addition, as shown in Table 5, when an organotin compound is used as a crosslinking accelerator (adhesive film No. 3), compared with the case where a crosslinking accelerator is not used (adhesive film No. 5), the peeling force is heated increase rate is high. On the other hand, when a zirconium chelate compound or a titanium chelate compound is used as a crosslinking promoter (adhesive film No. 1, 2), the increase rate by heating of peeling force is low, and heavy peeling is suppressed.

Further, as shown in Tables 6 to 8, when a metal chelate compound (zirconium chelate compound, titanium chelate compound, aluminum chelate compound) is used as a crosslinking accelerator (adhesive films No. 6 to 13, 16, 17), crosslinking The increase rate by heating of the adhesive force with respect to a to-be-adhered body is also lower than the case where an accelerator is not used (adhesive film No. 15, 19). Moreover, when a crosslinking accelerator is not used with respect to copolymer A (adhesive film No. 15), the adhesive force after heating increases significantly, and contaminates a to-be-adhered body. On the other hand, in adhesion film No. 6-14, the increase of the adhesive force by heating was suppressed and there was no contamination of a to-be-adhered body. Moreover, in spite of the adhesive force after a heating increasing significantly, in adhesive film No. 19, to-be-adhered body contamination is not seen. This is considered because the cohesive force of the copolymer B is higher than that of the copolymer A. In addition, about adhesion film No. 22, 25, and 28, it is thought that it is based on the difference in the thickness of the film used as the curing conditions at the time of adhesion film preparation, and a base material.

The present invention includes the following embodiments.

(Embodiment 1)

(A) a (meth)acrylic copolymer having a reactive functional group, (B) an isocyanate-based crosslinking agent, and (C) a metal chelate compound, wherein the (A) (meth)acrylic copolymer is obtained by living radical polymerization It is obtained, a weight average molecular weight is 200,000-2 million, and molecular weight distribution (PDI) is less than 3.0, The adhesive composition characterized by the above-mentioned.

(Embodiment 2)

The pressure-sensitive adhesive according to Embodiment 1, wherein the content of the (C) metal chelate compound is 2 parts by mass or more with respect to 1 part by mass in terms of metal of the metal compound derived from the chain transfer agent contained in the (A) (meth)acrylic copolymer. composition.

(Embodiment 3)

The reactive functional group of the (A) (meth)acrylic copolymer is at least one selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, a phosphine group, and an epoxy group, as described in Embodiment 1 or 2 Adhesive composition.

(Embodiment 4)

In Embodiments 1 to 3, the (A) (meth)acrylic copolymer contains 0.1% by mass to 20% by mass of a structural unit derived from a vinyl monomer having a reactive functional group in 100% by mass of the total copolymer. The pressure-sensitive adhesive composition according to any one of claims.

(Embodiment 5)

In any one of Embodiments 1 to 4, wherein the (A) (meth)acrylic copolymer contains 80% by mass or more of the structural unit derived from the (meth)acrylic monomer in 100% by mass of the total copolymer. The described pressure-sensitive adhesive composition.

(Embodiment 6)

The pressure-sensitive adhesive composition according to any one of Embodiments 1 to 5, wherein content of the (B) isocyanate crosslinking agent is 0.01 parts by mass to 20 parts by mass with respect to 100 parts by mass of the (meth)acrylic copolymer.

(Embodiment 7)

(C) the metal chelate compound is at least one metal atom selected from the group consisting of aluminum, zirconium, titanium, zinc, barium, calcium, copper, strontium, chromium, cobalt, iron, indium, magnesium, manganese and nickel A pressure-sensitive adhesive composition according to any one of Embodiments 1 to 6, comprising a.

(Embodiment 8)

The said (C) metal chelate compound contains the ligand represented by following formula (3), The adhesive composition in any one of Embodiments 1-7.

[In the formula, R ¹¹ and R ¹² each independently represent hydrogen, an alkyl group or an alkoxy group.]

(Embodiment 9)

The adhesive composition in any one of Embodiments 1-8 whose content of the said (C) metal chelate compound is 0.01 mass part - 0.5 mass part with respect to 100 mass parts of (meth)acrylic-type copolymers.

(Embodiment 10)

The pressure-sensitive adhesive composition according to any one of Embodiments 1 to 9, wherein the pressure-sensitive adhesive composition further contains (D) a crosslinking retarder.

(Embodiment 11)

The pressure-sensitive adhesive composition according to any one of Embodiments 1 to 10, which is for optical use.

(Embodiment 12)

It has a base film and the adhesive layer formed from the adhesive composition in any one of Embodiments 1-11, The adhesive film characterized by the above-mentioned.

(Embodiment 13)

An image display device comprising the pressure-sensitive adhesive film according to Embodiment 12.

Claims (13)

(A) a (meth)acrylic copolymer having a reactive functional group, (B) an isocyanate-based crosslinking agent, and (C) a metal chelate compound,
The (A) (meth)acrylic copolymer is obtained by living radical polymerization, has a weight average molecular weight of 200,000 to 2 million, and has a molecular weight distribution (PDI) of less than 3.0,
The content of the (C) metal chelate compound is 2 parts by mass to 40 parts by mass relative to 1 part by mass in terms of metal of the metal compound derived from the chain transfer agent contained in the (A) (meth)acrylic copolymer. Adhesive composition. The method according to claim 1,
Content of the said (C) metal chelate compound is 4 mass parts - 30 mass parts with respect to 1 mass part of metal conversion of the metal compound derived from the chain transfer agent contained in the said (A) (meth)acrylic-type copolymer, The adhesive composition. The method according to claim 1,
The (A) (meth) acrylic copolymer having a reactive functional group is at least one selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, a phosphine group, and an epoxy group, The pressure-sensitive adhesive composition. The method according to claim 1,
The (A) (meth)acrylic copolymer contains the structural unit derived from the vinyl monomer which has a reactive functional group in 100 mass % of the whole copolymer, 0.1 mass % - 20 mass %, The adhesive composition. The method according to claim 1,
The said (A) (meth)acrylic-type copolymer contains the structural unit derived from a (meth)acrylic monomer 80 mass % or more in 100 mass % of whole copolymers, The adhesive composition. The method according to claim 1,
The pressure-sensitive adhesive composition in which content of the said (B) isocyanate type crosslinking agent is 0.01 mass part - 20 mass parts with respect to 100 mass parts of (meth)acrylic-type copolymers. The method according to claim 1,
(C) the metal chelate compound is at least one metal atom selected from the group consisting of aluminum, zirconium, titanium, zinc, barium, calcium, copper, strontium, chromium, cobalt, iron, indium, magnesium, manganese and nickel A pressure-sensitive adhesive composition comprising a. The method according to claim 1,
The said (C) metal chelate compound contains the ligand represented by following formula (3), The adhesive composition.

[Wherein, R ¹¹ and R ¹² each independently represent hydrogen, an alkyl group, or an alkoxy group.] The method according to claim 1,
The adhesive composition whose content of the said (C) metal chelate compound is 0.01 mass part - 0.5 mass part with respect to 100 mass parts of (meth)acrylic-type copolymers. The method according to claim 1,
The adhesive composition in which the said adhesive composition further contains (D) a crosslinking retarder. The method according to claim 1,
Optical use, pressure-sensitive adhesive composition. It has a base film and the adhesive layer formed from the adhesive composition of any one of Claims 1-11, The adhesive film characterized by the above-mentioned. An image display device comprising the adhesive film according to claim 12 .