KR20130097113A - Pressure-sensitive adhesive composition, pressure-sensitive adhesive layer and pressure-sensitive adhesive sheet - Google Patents

Abstract

PURPOSE: An adhesive sheet is provided to be able to prevent the generation of bubbles as the adhesion to a substance to be adhered is excellent without separate pressurization when adhering to the substance to be adhered. CONSTITUTION: An adhesive composition includes acrylic polymer containing polyoxypropylene monoalkyl ether (meth)acrylate in which the mole number of the oxypropylene unit is 4 or more as a monomer component, and a cross linking agent. The acrylic polymer contains 30-94.9 weight% of alkyl (meth)acrylate having C4-18 alkyl, 5-40 weight% of polyoxypropylene monoalkyl ether (meth)acrylate in which the mole number of the oxypropylene unit is 4 or more, and 0.1-10 weight% of functional group-containing monomer. An adhesive sheet is obtained by forming an adhesive layer produced by cross-linking the adhesive composition on a substrate. [Reference numerals] (AA) Test piece (adhesion sheet); (BB) Body to be adhered

Description

PRESSURE-SENSITIVE ADHESIVE COMPOSITION, PRESSURE-SENSITIVE ADHESIVE LAYER AND PRESSURE-SENSITIVE ADHESIVE SHEET}

This invention relates to the adhesive sheet excellent in wettability, the adhesive layer used for this, and an adhesive composition.

The pressure-sensitive adhesive sheet has a gel-like soft pressure-sensitive adhesive layer on a substrate such as a plastic film or paper, and the pressure-sensitive adhesive layer exhibits adhesive strength by being wet to the adherend while being solid. That is, the pressure-sensitive adhesive layer is required to be sufficiently wet with respect to the adherend. On the other hand, the adhesive layer needs cohesion force (hardness) to the extent which resists peeling. Therefore, an adhesive sheet is designed in consideration of wettability and cohesion force as opposing characteristics.

For this reason, in general, an adhesive sheet is pressurized when bonding to a to-be-adhered body, and in some cases, it is pressurized in a heated state, and it is constructed so that it may fully adhere to a to-be-adhered body. Thus, when pressurization and heating are possible at the time of construction, even if the wettability of an adhesive tape is inferior, it can be used, but when a to-be-adhered body is a micro part or a problem arises about heating, such construction is difficult. Become.

Moreover, as a case where wettability with respect to a to-be-adhered body becomes a problem, the case where a bubble enters between an to-be-adhered body and an adhesive sheet can be considered. For example, in order to prevent a bubble from remaining when bonding a decorative film, it is known to form a convex protrusion in an adhesive layer, or to form a concave stripe, and to push out a bubble, but these are essentially wettability of an adhesive sheet. It is not to improve.

As a method of improving the wettability of an adhesive sheet, it is known to make the acryl-type polymer which comprises an adhesive layer into the graft polymer structure which has an alkylene oxide in a side chain. That is, in patent document 1, 51-100 weight% of (meth) acrylic-acid alkylene oxide adducts, 0-49 weight% of (meth) acrylic-type monomers other than the above, and 0-49 weight% of other polymerizable monomers are monomers. The surface protection film formed by forming the adhesive layer which crosslinks the (meth) acrylic-type (co) polymer as a component and the adhesive composition containing a crosslinking agent on a support film is disclosed. In addition, the crosslinking agent is mix | blended and used for patent document 2, As a solvent-type re-peelable adhesive composition containing an adhesive polymer, this adhesive polymer has a polymer structure whose glass transition temperature is 0 degreeC or more, and a C4-C12 alkyl group. A long chain portion containing monomer (B) and a functional group containing monomer (C) containing an alkyl (meth) acrylate (A), an alkylene oxide chain and / or a long chain alkyl group as essential components, and other monomers ( A pressure-sensitive adhesive layer obtained from a solvent-based re-peelable pressure-sensitive adhesive composition, which is a graft and / or a block polymer having a polymer structure synthesized from a raw material monomer component containing D), wherein the pressure-sensitive adhesive layer is formed on at least one side of the support base material. An adhesive product for peeling is disclosed.

However, in invention of patent document 2, even if it is the adhesive surface property of a narrow range of 4 cm x 4 cm, 20 seconds or more are required until the whole is soaked, and it did not have sufficient wettability.

Japanese Patent Laid-Open No. 2005-200540 Japanese Patent Publication No. 2009-227737

Therefore, the objective of this invention is providing the adhesive composition excellent in wettability, an adhesive layer, and the adhesive sheet using the same in order to solve the problem with the conventional acrylic adhesive.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined in order to achieve the objective mentioned above, and, as a result, the acrylic polymer containing the polyoxypropylene monoalkyl ether (meth) acrylate whose addition mole number of an oxypropylene unit is four or more as a monomer component, and a crosslinking agent are included. It was found out that the said subject can be solved by the adhesive sheet which forms the adhesive layer which consists of an adhesive composition on a base material, and came to solve this invention.

The reason why the wettability of the pressure-sensitive adhesive can be improved in the present invention is by using an acrylic polymer containing polyoxypropylene monoalkyl ether (meth) acrylate having an addition mole number of 4 or more as the monomer component. In this invention, the side chain whose addition mole number of an oxypropylene unit is four or more can be introduce | transduced into an acryl-type polymer by copolymerizing the monomer mixture containing polyoxypropylene monoalkyl ether (meth) acrylate whose addition mole number of an oxypropylene unit is four or more. have. For this reason, it is thought that an ether bond with a low rotational energy of a bond can be introduce | transduced into a polymer backbone, and the rotational freedom of a molecule is raised and it contributes to the improvement of wettability. If the terminal is a polyoxypropylene chain of a hydroxyl group which is not substituted with an alkyl group, a sufficient improvement in wettability is not achieved because the surface free energy of the hydroxyl group is high.

In addition, in this invention, the added mole number of an oxypropylene unit needs to be four or more. When the number of added moles is small, it is thought that it is difficult to improve wettability because the ether bond which improves wettability is buried in an adhesive, and the ether bond which exists on the surface of an adhesive becomes less.

This invention provides the adhesive composition containing the acryl-type polymer containing the polyoxypropylene monoalkyl ether (meth) acrylate whose addition mole number of an oxypropylene unit is four or more as a monomer component, and a crosslinking agent.

Especially in the adhesive composition of this invention, the said acrylic polymer is the polyoxypropylene monoalkyl ether whose addition mole number of the oxypropylene unit is 30 weight%-94.9 weight% of the alkyl (meth) acrylate which has a C4-C18 alkyl group, and 4 or more. It is preferable to contain 5-40 weight% of (meth) acrylates and 0.1-10 weight% of functional group containing monomers as a monomer component. Moreover, the said acrylic polymer can further contain other copolymerizable monomer as a monomer component in content of 20 weight% or less.

Moreover, in this invention, it is preferable that the polyoxypropylene monoalkyl ether (meth) acrylate whose addition mole number of the said oxypropylene unit is four or more is hexaoxypropylene monomethyl ether (meth) acrylate.

In another aspect, the present invention provides the pressure-sensitive adhesive composition characterized in that it contains 1 to 10 parts by weight of a crosslinking agent based on 100 parts by weight of the acrylic polymer. It is especially preferable that the said crosslinking agent is an isocyanate type crosslinking agent.

Moreover, this invention provides the adhesive layer which crosslinks the said adhesive composition, and the adhesive sheet which forms this adhesive layer on a base material.

The adhesive composition, the adhesive layer, and the adhesive sheet of this invention are excellent in wettability compared with the conventional acrylic adhesive sheet. For this reason, the adhesive sheet of this invention can fully adhere to a to-be-adhered body, even if it does not pressurize especially when bonding to an to-be-adhered body, and can fully prevent generation | occurrence | production of an air bubble etc .. Therefore, it can use as various adhesive sheets.

1 is a schematic view for explaining a method of evaluating wettability in an example.

Hereinafter, embodiments of the present invention will be described in detail.

The adhesive composition of this invention contains the acryl-type polymer and crosslinking agent which contain polyoxypropylene monoalkyl ether (meth) acrylate whose addition mole number of an oxypropylene unit is four or more as a monomer component.

(Acrylic polymer)

In this invention, an acryl-type polymer contains polyoxypropylene monoalkyl ether (meth) acrylate whose addition mole number of an oxypropylene unit is four or more as a monomer component, It is characterized by the above-mentioned. In particular, 30% by weight to 94.9% by weight of alkyl (meth) acrylate having an alkyl group having 4 to 18 carbon atoms and 5 to 40% by weight of polyoxypropylene monoalkyl ether (meth) acrylate having an added mole number of oxypropylene units of 4 or more. It is preferable that the monomer component comprises%, 0.1 to 10% by weight of the functional group-containing monomer, and 0 to 20% by weight of the other copolymerizable monomer.

As a specific example of the alkyl (meth) acrylate which has a C4-C18 alkyl group which comprises an acryl-type polymer, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (Meth) acrylate, amyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, Ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth ) Acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylic Rate Of alkyl (meth) acrylate. These may be used independently and may use 2 or more types together.

It is preferable that the content rate of the alkyl (meth) acrylate which has a C4-C18 alkyl group is 30 to 94.9 weight% in all the monomer components, It is more preferable that it is 46 to 93.5 weight%, 52 weight It is more preferable that it is% to 92 weight%.

The polyoxypropylene monoalkyl ether (meth) acrylate which can be used by this invention is polyoxypropylene monoalkyl ether (meth) acrylate with the addition mole number of an oxypropylene unit 4 or more, and is represented by following General formula (1) or (2) It can be represented as

R ¹ -O- (CH ₂ CH (CH ₃ ) O) _n -R ² (1)

R ² -O- (CH ₂ CH (CH ₃ ) O) _n -R ¹ (2)

In Formulas (1) and (2), R ¹ is a substituent including an acryloyl group (CH ₂ = CHCO-) or a methacryloyl group (CH ₂ = C (CH ₃ ) CO-).

In the formula (1), R ² is a C ₁ to C ₂₀ aliphatic hydrocarbon group, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group , Hexyl group, heptyl group, octyl group, isooctyl group, 2-ethylhexyl group, nonyl group, decyl group, isodecyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group , Heptadecyl group, octadecyl group, eicosyl group and the like. In the present invention, R ² is preferably a methyl group, an ethyl group, a butyl group, or a 2-ethylhexyl group.

In addition, in the said General formula (1) and (2), n represents the added mole number of an oxypropylene unit. In the present invention, n is 4 or more, preferably 4 to 18, more preferably 4 to 15. When the added mole number n of the oxypropylene unit is 4 or more, it means that the ether bond having low rotational energy of the bond (high degree of rotational freedom of the molecule) in the polymer is long, so that the number of ether bonds that can exist on the pressure-sensitive adhesive surface is large, and the wettability is improved. The advantage is that it can be improved. On the other hand, when the added mole number n is less than 4, the ether bond which improves wettability may be buried in an adhesive, and since the ether bond which exists on the adhesive surface becomes small, it may become difficult to improve wettability. In addition, when the number of moles of n exceeds 18, purification becomes difficult during the production of the polyoxypropylene monoalkyl ether (meth) acrylate, and the polyfunctional component which is an impurity increases, so that a gel may be generated during polymer polymerization.

In addition, in this invention, the added mole number n of an oxypropylene unit is the added mole number derived from an individual molecular structure. In addition, when it is a mixture of what the added mole number n of an oxypropylene unit has in a commercial item etc., the average value computed from the number average molecular weight is used. The number average molecular weight can be measured by GPC (gel permeation chromatography), and can be calculated by polystyrene conversion.

As a specific example of the polyoxypropylene monoalkyl ether (meth) acrylate which can be used by this invention,

Examples of R ² being a methyl group include tetraoxypropylene monomethyl ether (meth) acrylate, pentaoxypropylene monomethyl ether (meth) acrylate, hexaoxypropylene monomethyl ether (meth) acrylate, and decaoxypropylene monomethyl ether. (Meth) acrylate, dodecaoxypropylene monomethyl ether (meth) acrylate, pentadecaoxypropylene monomethyl ether (meth) acrylate, octadecaoxypropylene monomethyl ether (meth) acrylate, etc .;

As an example where R <^2> is an ethyl group, tetraoxypropylene monoethyl ether (meth) acrylate, pentaoxypropylene monoethyl ether (meth) acrylate, hexaoxypropylene monoethyl ether (meth) acrylate, and decaoxypropylene monoethyl ether (Meth) acrylate, dodecaoxypropylene monoethyl ether (meth) acrylate, pentadecaoxypropylene monoethyl ether (meth) acrylate, octadecaoxypropylene monoethyl ether (meth) acrylate, etc .;

Examples of R ² being a butyl group include tetraoxypropylene monobutyl ether (meth) acrylate, pentaoxypropylene monobutyl ether (meth) acrylate, hexaoxypropylene monobutyl ether (meth) acrylate, and decaoxypropylene monobutyl ether (Meth) acrylate, dodecaoxypropylene monobutyl ether (meth) acrylate, pentadecaoxypropylene monobutyl ether (meth) acrylate, octadecaoxypropylene monobutyl ether (meth) acrylate, etc .;

Examples of R ² being a 2-ethylhexyl group include tetraoxypropylene mono 2-ethylhexyl ether (meth) acrylate, pentaoxypropylene mono2-ethylhexyl ether (meth) acrylate and hexaoxypropylene mono 2-ethylhexyl Ether (meth) acrylate, decaoxypropylene mono 2-ethylhexyl ether (meth) acrylate, dodecaoxypropylene mono 2-ethylhexyl ether (meth) acrylate, pentadecaoxypropylene mono 2-ethylhexyl ether (meth ) Acrylate, octadecaoxypropylene mono 2-ethylhexyl ether (meth) acrylate, etc .;

Examples of R ² being a dodecyl group include tetraoxypropylene monododecyl ether (meth) acrylate, pentaoxypropylene monododecyl ether (meth) acrylate, hexaoxypropylene monododecyl ether (meth) acrylate, and decaoxy Propylene monododecyl ether (meth) acrylate, dodecaoxypropylene monododecyl ether (meth) acrylate, pentadecaoxypropylene monododecyl ether (meth) acrylate, octadecaoxypropylene monododecyl ether (meth) Acrylates and the like;

Examples of R ² being an octadecyl group include tetraoxypropylene monooctadecyl ether (meth) acrylate, pentaoxypropylene monooctadecyl ether (meth) acrylate, hexaoxypropylene monooctadecyl ether (meth) acrylate, and deca Oxypropylene monooctadecyl ether (meth) acrylate, dodecaoxypropylene monooctadecyl ether (meth) acrylate, pentadecaoxypropylene monooctadecyl ether (meth) acrylate, octadecaoxypropylene monooctadecyl ether (meth ) Acrylates and the like; .

In the present invention, these polyoxypropylene monoalkyl ether (meth) acrylates may be used alone or in combination.

These polyoxypropylene monoalkyl ether (meth) acrylates are reactions of corresponding polyoxypropylene monoalkyl ethers with acid chlorides such as acrylic acid chlorides and methacrylic acid chlorides, or corresponding polyoxypropylene monoalkyl ethers with 2- It can synthesize | combine easily by reaction of (meth) acrylic acid ester which has isocyanate groups, such as acryloyloxyethyl isocyanate and 2-methacryloyl oxyethyl isocyanate. Commercially available polyoxypropylene monoalkyl ether (meth) acrylates can also be used.

In this invention, it is preferable that the content rate of the polyoxypropylene monoalkyl ether (meth) acrylate whose addition mole number of an oxypropylene unit is four or more is 5 weight%-40 weight% in all the monomer components, 6 weight%-30 It is more preferable that it is weight%, and it is still more preferable that it is 7 to 28 weight%. When the content ratio of the polyoxypropylene monoalkyl ether (meth) acrylate is in the range of 5% by weight to 40% by weight, when an ether bond having a low rotational energy of a bond (high degree of rotational freedom of the molecule) is introduced into the polymer, There is an advantage that the number of ether bonds that may be present on the pressure-sensitive adhesive surface can improve the wettability. On the other hand, when the content of the polyoxypropylene monoalkyl ether (meth) acrylate is less than 5% by weight, there are few ether bonds to improve wettability, soak them in the pressure-sensitive adhesive, and there are less ether bonds present on the pressure-sensitive adhesive surface to improve wettability. It may become difficult, and when it exceeds 40 weight%, since the ratio of polyoxypropylene di (meth) acrylate which is an impurity increases, it may become easy to produce a gel during polymer polymerization.

In the present invention, the functional group-containing monomer constituting the acrylic polymer imparts polarity or reactivity to the acrylic polymer, or contributes to the formation of a crosslinked structure by reacting with a crosslinking agent described later, for example, containing functional groups such as carboxyl groups and hydroxyl groups. The functional group containing monomer to mention is mentioned.

As a specific example of a functional group containing monomer, Carboxyl group containing monomers, such as (meth) acrylic acid, itaconic acid, maleic acid, a fumaric acid, a crotonic acid;

2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl ( Meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, Hydroxyl group-containing monomers such as hydroxyalkyl (meth) acrylates such as [4- (hydroxymethyl) cyclohexyl] methyl acrylate; .

Moreover, in this invention, as a functional group containing monomer, N-methylol acrylamide, N-methylol methacrylamide, N- (2-hydroxyethyl) acrylamide, N- (2-hydroxyethyl) methacrylamide, N- (2-hydroxypropyl) acrylamide, N- (2-hydroxypropyl) methacrylamide, N- (1-hydroxypropyl) acrylamide, N- (1-hydroxypropyl) methacrylamide, N- (3-hydroxypropyl) acrylamide, N- (3-hydroxypropyl) methacrylamide, N- (2-hydroxybutyl) acrylamide, N- (2-hydroxybutyl) methacrylamide, N- (3-hydroxybutyl) acrylamide, N- (3-hydroxybutyl) methacrylamide, N- (4-hydroxybutyl) acrylamide, N- (4-hydroxybutyl) methacrylamide, etc. N-hydroxyalkyl (meth) acrylamide of;

Monomers having an epoxy group such as glycidyl (meth) acrylate, methylglycidyl (meth) acrylate, allyl glycidyl ether,

(Meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N- Monomers having amide groups such as methylol propane (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, and N-vinylcarboxylic acid amide;

Monomers having amino groups such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate and t-butylaminoethyl (meth) acrylate;

Monomers having cyano groups such as acrylonitrile and methacrylonitrile;

Monomers having keto groups such as diacetone (meth) acrylamide, diacetone (meth) acrylate, vinyl methyl ketone, vinyl ethyl ketone, allyl acetoacetate, and vinyl acetoacetate;

Isocyanate group-containing monomers such as 2- (meth) acryloyloxyethyl isocyanate; . These functional group containing monomers may be used independently and may be used in combination.

It is preferable that the content rate of a functional group containing monomer is 0.1 to 10 weight% among all the monomer components, It is more preferable that it is 0.5 to 9 weight%, It is further more preferable that it is 1 to 8 weight%. If the content ratio of the functional group-containing monomer is less than 0.1% by weight, the addition effect thereof becomes difficult to be obtained, for example, crosslinking formation becomes insufficient, cohesive force of the pressure-sensitive adhesive composition cannot be obtained, and the pressure-sensitive adhesive sheet is shifted at the time of fixing the article, When peeling an adhesive sheet, a pull residue may generate | occur | produce. On the other hand, when the content rate of a functional group containing monomer exceeds 10 weight%, since the cohesion force of an acrylic polymer becomes large, fluidity | liquidity may fall and wettability may fall.

In addition, in the monomer component which comprises an acrylic polymer in this invention, the copolymerization monomer etc. for adjusting the glass transition point and adhesiveness of an acrylic polymer can be used in the range which does not impair the effect of this invention. As such a copolymerizable monomer, the alkyl (meth) acrylate which has alkyl groups of less than 4 carbon atoms, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and isopropyl (meth) acrylate, etc. Ryu;

Vinyl esters such as vinyl acetate and vinyl propionate;

Aromatic vinyl compounds such as styrene, substituted styrene (α-methylstyrene, etc.) and vinyltoluene;

Alicyclic hydrocarbon (meth) acrylates such as cyclohexyl (meth) acrylate, cyclopentyldi (meth) acrylate, and isobornyl (meth) acrylate;

Aromatic ring-containing (meth) acrylates such as phenyl (meth) acrylate, phenoxyethyl (meth) acrylate and benzyl (meth) acrylate;

Olefin monomers such as ethylene, propylene, isoprene, butadiene and isobutylene;

Halogen atom-containing monomers such as vinyl chloride and vinylidene chloride;

Alkoxy group-containing monomers such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate;

Vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether;

N-vinyl-2-pyrrolidone, N- (1-methylvinyl) pyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam, N- (meth) acryloylmorpholine, tetrahydrofurfuryl (meth) acrylate Monomers having heterocycles such as; And the like.

In this invention, you may use as a copolymerizable monomer the monomer which has several functional groups in 1 molecule individually or in combination of 2 or more types as appropriate. Such a polyfunctional monomer can be useful for improving heat resistance and cohesiveness of the pressure-sensitive adhesive. Specific examples of the polyfunctional monomers include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and (poly Mono or polyalkylene glycol di (meth) acrylates such as ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and (poly) propylene glycol di (meth) acrylate; Neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) Acrylate, tetramethylol methane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, divinylbenzene, etc. are mentioned.

As a copolymerizable monomer, you may use the monomer which has an alkoxysilyl group individually or in combination of 2 or more types as appropriate. Such an alkoxysilyl group-containing monomer can be helpful for improving heat resistance and cohesiveness of the pressure-sensitive adhesive. As a specific example of the alkoxy silyl group containing monomer, 3- (meth) acryloxypropyl trimethoxysilane, 3- (meth) acryloxypropyl triethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, And (meth) acryloxyalkylsilane derivatives such as 3- (meth) acryloxypropylmethyldiethoxysilane and vinyltrimethoxysilane.

These copolymerizable monomers can be used individually or in combination of 2 or more types as appropriate. For example, a copolymerizable monomer can be used in the range of 20 weight% or less (0 weight%-20 weight%) among all monomer components, and is usually 15 weight% or less (0 weight%-15 weight%), It is preferable to set it as 12 weight% or less (0 weight%-12 weight%). The minimum of the usage-amount in the case of using a copolymerizable monomer is not specifically limited, What is necessary is just the quantity which can achieve the objective of using the said monomer. Usually, it is suitable to make the usage-amount of a copolymerizable monomer into 0.001 weight% or more in all the monomer components.

The acrylic polymer used for this invention can be manufactured by superposing | polymerizing the said monomer component by well-known polymerization methods, such as solution polymerization, block polymerization, emulsion polymerization, and various radical polymerization. Moreover, any of a random copolymer, a block copolymer, a graft copolymer, etc. may be sufficient as the acryl-type polymer obtained.

In solution polymerization, for example, ethyl acetate, toluene or the like is used as the polymerization solvent. You may mix and use these polymerization solvents. In a specific solution polymerization example, the reaction is performed under an inert gas stream such as nitrogen, and is usually carried out under reaction conditions of about 2 hours or more (for example, about 5 hours to 30 hours) at about 50 ° C to 70 ° C. .

The polymerization initiator, chain transfer agent, emulsifier, etc. used for radical polymerization are not specifically limited, It can select suitably and can use. In addition, the weight average molecular weight of the acryl-type polymer mentioned later can be controlled with the usage-amount of a polymerization initiator, a chain transfer agent, and reaction conditions, and the usage-amount is adjusted suitably according to these types.

As a polymerization initiator, for example, 2,2'- azobisisobutyronitrile, 2,2'- azobis (2-amidinopropane) dihydrochloride, 2,2'- azobis [2- (5 -Methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) sulfate, 2,2'-azobis (N, N'- Azo initiators such as dimethylene isobutyl amidine) and 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (manufactured by Wako Pure Chemical Industries, Ltd., VA-057); Persulfates such as potassium sulfate and ammonium persulfate, di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxy Neodecanoate, t-hexyl peroxy pivalate, t-butyl peroxy pivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, di (4-methylbenzoyl) peroxy Peroxide initiators such as dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di (t-hexylperoxy) cyclohexane, t-butylhydroperoxide, hydrogen peroxide, persulfate and sodium hydrogen sulfite Although a redox initiator which combined peroxide and a reducing agent, such as a combination, a combination of a peroxide, and sodium ascorbate, etc. are mentioned, It is not limited to this.

Although the said polymerization initiator may be used independently and may be used in mixture of 2 or more type, It is preferable that content as a whole is 0.005 weight part-about 1 weight part with respect to 100 weight part of all monomer components, 0.02 weight part It is more preferable that it is about 0.5 weight part.

As a chain transfer agent, for example, lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, thioglucolic acid 2-ethylhexyl, 2,3-dimercapto-1 Propanol etc. are mentioned. Although a chain transfer agent may be used independently and may mix and use 2 or more types, content as a whole is about 0.1 weight part or less with respect to 100 weight part of all monomer components.

Moreover, as an emulsifier used when emulsion-polymerizing, anionic emulsifiers, such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, polyoxyethylene alkyl ether ammonium sulfate, and polyoxyethylene alkyl phenyl ether sodium sulfate, for example And nonionic emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene-polyoxypropylene block polymer. These emulsifiers may be used independently and may use 2 or more types together.

Moreover, as a reactive emulsifier, the emulsifier into which radically polymerizable functional groups, such as a propenyl group and an allyl ether group, were introduce | transduced is mentioned. Specifically, for example, aqualon HS-10, HS-20, KH-10, BC-05, BC-10, BC-20 (all are manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.), Adeka Riasorb SE10N (ADEKA) Company) etc. are mentioned. Since a reactive emulsifier is accommodated in a polymer chain after superposition | polymerization, water resistance becomes good and it is preferable. As for the usage-amount of an emulsifier, 0.5-1 weight part is more preferable from a viewpoint of 0.3-5 weight part, polymerization stability, and mechanical stability with respect to 100 weight part of total amounts of a monomer component.

The acrylic polymer thus obtained has a weight average molecular weight of 50,000 to 2 million, preferably 100,000 to 1.5 million, and more preferably 300,000 to 1 million. When the weight average molecular weight is less than 50,000, the cohesion force of the pressure-sensitive adhesive composition decreases, so that a deviation occurs at the time of adhesion fixing, or a pool residue occurs at the time of peeling. On the other hand, when the weight average molecular weight exceeds 2 million, the fluidity | liquidity of a polymer falls and there exists a tendency for wettability to fall. In addition, a weight average molecular weight can be measured by GPC (gel permeation chromatography) and it can calculate by polystyrene conversion.

(Crosslinking agent)

The adhesive composition of this invention contains a crosslinking agent. As a crosslinking agent used for this invention, an isocyanate compound, an epoxy resin, a melamine type resin, an aziridine derivative, a metal chelate compound, etc. are used.

As a crosslinking agent in this invention, it is preferable to use an isocyanate type crosslinking agent from a viewpoint of obtaining appropriate cohesion force by crosslinking formation in reaction with an acrylic polymer.

An isocyanate type crosslinking agent used as a crosslinking agent means the compound which has two or more isocyanate groups (including the isocyanate regeneration type functional group which temporarily protected the isocyanate group by blocking agent or water quantification, etc.) in 1 molecule.

As an isocyanate type crosslinking agent, aromatic isocyanate, such as tolylene diisocyanate and xylene diisocyanate, alicyclic isocyanate, such as isophorone diisocyanate, aliphatic isocyanate, such as hexamethylene diisocyanate, etc. are mentioned.

More specifically, Lower aliphatic polyisocyanates, such as butylene diisocyanate and hexamethylene diisocyanate, cycloaliphatic diisocyanates, such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate, 2, 4-, for example Aromatic diisocyanates such as tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, polymethylene polyphenyl isocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Co., Ltd., Coronate L), trimethylolpropane / hexamethylene diisocyanate trimer adduct (Nippon Polyurethane Co., Ltd., brand name coronate HL), isocyanurate body of Nippon Polyurethane Co., Ltd., brand name Coro Nate H Isocyanate adducts such as X), polyether polyisocyanates, polyester polyisocyanates, and polyisocyanates polyfunctionalized with adducts of these and various polyols, isocyanurate bonds, biuret bonds, allophanate bonds, and the like. Can be. Among them, it is preferable to use aliphatic isocyanate because the reaction rate is high.

As the epoxy resin, N, N, N ', N'-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, and ethylene glycol di Hexamethylol melamine etc. are mentioned as melamine type resins, such as glycidyl ether, propylene glycol diglycidyl ether, terephthalic acid diglycidyl ester acrylate, and spiroglycol diglycidyl ether. As an aziridine derivative, the Sogo Pharmaceutical Co., Ltd. make, a brand name HDU, a brand name TAZM, a brand name TAZO etc. as a commercial item are mentioned, for example. Moreover, as a metal chelating compound, aluminum, iron, tin, titanium, nickel, etc. are mentioned as a metal component, acetylene, methyl acetoacetate, ethyl lactate, etc. are mentioned as a chelate component.

It is preferable that it is 1 weight part-10 weight part with respect to 100 weight part of acrylic polymer, and, as for content of the crosslinking agent used for this invention, it is more preferable that it is 2 weight part-6 weight part. When content is less than 1 weight part, crosslinking formation by a crosslinking agent becomes inadequate and there exists a tendency for the cohesion force of an adhesive composition to become small. On the other hand, when content exceeds 10 weight part, the cohesion force of a polymer is large and fluidity falls and there exists a tendency for wettability to become inadequate.

The pressure-sensitive adhesive composition of the present invention may contain other additives as long as it does not impair the effect thereof. For example, fillers (inorganic fillers, organic fillers, etc.), anti-aging agents, antioxidants, ultraviolet absorbers, charging Various additives, such as an inhibitor, a lubricating agent, surfactant, a plasticizer, a surface lubricant, a leveling agent, and a coloring agent (pigment, dye, etc.) may be mix | blended.

The pressure-sensitive adhesive layer of the present invention comprises the pressure-sensitive adhesive composition, and is typically formed by crosslinking the pressure-sensitive adhesive composition. Moreover, the adhesive sheet of this invention forms such an adhesive layer on a base material. In that case, although crosslinking of an adhesive composition is generally performed after application | coating of an adhesive composition, it is also possible to transfer the adhesive layer which consists of an adhesive composition after crosslinking to a support film etc.

As a method of forming an adhesive layer, the adhesive composition is apply | coated to a base material, the polymerization solvent etc. are dried and removed, a crosslinking process, the adhesive layer is formed on a base material, and the adhesive composition was peeled off. It is apply | coated to a peeling liner (for example, a silicone-treated peeling film), etc., and it removes a polymerization solvent, etc., crosslinks, and forms an adhesive layer, and is produced by the method etc. which transfer to a base material. In addition, in application | coating of an adhesive composition, you may add a 1 or more types of solvent other than a polymerization solvent suitably.

The base material may be, for example, a film made of polyolefin (polyethylene, polypropylene, ethylene-propylene copolymer, etc.), a film made of polyester (polyethylene terephthalate, etc.), a vinyl chloride resin film, a vinyl acetate resin film, or poly Plastic films such as a mid resin film, a polyamide resin film, a fluorine resin film, and other cellophanes; Papers such as Japanese paper, kraft paper, glassine paper, fine paper, synthetic paper, and top coated paper; Various fibrous materials (natural fibers, semi-synthetic fibers or synthetic fibers may be used. For example, cotton fibers, stable fibers, manila hemp, pulp, rayon, acetate fibers, polyester fibers, polyvinyl alcohol fibers, polyamides). Fibers such as woven fabrics and nonwoven fabrics of single fibers or blends of fibers, polyolefin fibers and the like; Rubber sheets made of natural rubber, butyl rubber and the like; Foam sheets composed of foams such as foamed polyurethane and foamed polychloroprene rubber; Metal foils such as aluminum foil and copper foil; These complexes; Etc. may be used. The plastic film may be a non-stretched type or a stretched type (uniaxially stretched type or biaxially stretched type).

In addition, in order to improve the adhesiveness between the pressure-sensitive adhesive layer and the base material, the surface of the base material (in particular, the surface of the side where the pressure-sensitive adhesive layer is provided) may be, for example, known such as corona discharge treatment, plasma treatment, application of a primer, or the like. Ordinary surface treatment may be performed. Although the thickness of a base material can be suitably selected according to the objective, Generally, it is about 10 micrometers-500 micrometers, Preferably it is about 10 micrometers-200 micrometers.

Thus, in the process of apply | coating and drying the adhesive composition of this invention on a base material or a peeling liner, and forming an adhesive layer, the method suitable for drying an adhesive composition can be employ | adopted according to the objective. Preferably, the method of heat-drying the said coating film is used. The heat drying temperature is preferably 40 ° C to 200 ° C, more preferably 50 ° C to 180 ° C, and particularly preferably 70 ° C to 170 ° C. By setting the heating temperature in the above range, a pressure-sensitive adhesive layer having excellent adhesive properties can be obtained.

As the drying time, an appropriate time may be employed. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

Various methods are used as a formation method of an adhesive layer. Specifically, for example, roll coating, kiss roll coating, gravure coating, reverse coating, roll brush, spray coating, deep roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, die coater, etc. And extrusion coating methods.

The thickness of an adhesive layer is not specifically limited, For example, it is about 1 micrometer-about 100 micrometers. Preferably they are 2 micrometers-50 micrometers, More preferably, they are 2 micrometers-40 micrometers, More preferably, they are 5 micrometers-35 micrometers.

The adhesive sheet of this invention provides the adhesive layer with high wettability mentioned above, and is excellent in wettability compared with the conventional acrylic adhesive sheet. The wettability to the adherend can be evaluated by the method described in Examples described later, and it is preferable to wet the distance of 100 mm in a time of less than 10 seconds, more preferably 7 seconds or less, even more preferably 5 seconds or less. All. When wet time is less than 10 second, even when it does not pressurize especially when joining to a to-be-adhered body, it fully adheres to an to-be-adhered body and does not generate | occur | produce foam etc. substantially.

Moreover, it is preferable that the adhesive force of the adhesive sheet of this invention is 0.02 N / 250 mm or more to an acryl plate or a glass plate, More preferably, it is 0.05 N / 250 mm or more, More preferably, it is 0.10 N / 250 mm or more (usually 2.00 N / 250 mm or less).

Since the adhesive layer obtained is excellent in wettability, it is useful in the field of various adhesive sheets, for example, the adhesive sheet for electrical insulation, the adhesive sheet for both surfaces, the adhesive sheet for surface protection, the masking tape, a repeelable label, etc. Do.

[Example]

EMBODIMENT OF THE INVENTION Hereinafter, although the Example etc. which show a structure and effect of this invention concretely are demonstrated, this invention is not limited to this. In addition, the evaluation item in the Example etc. was measured as follows.

<Measurement of weight average molecular weight>

The weight average molecular weight of the produced polymer was measured by GPC (gel permeation chromatography), and it calculated by polystyrene conversion.

Apparatus: manufactured by Tosoh Corporation, HLC-8220 GPC

Column: Tosoh Corporation, TSKgel Super HZM-H, H-RC, HZ-H

Flow rate: 0.6 ml / min, injection volume: 20 μl, column temperature: 40 ° C.,

Eluent: THF, injection sample concentration: 0.1% by weight

<Evaluation of wettability>

Test piece: 25 mm × 100 mm

Substrate: Glass plate (manufactured by Matsunami Glass Industrial Co., Ltd., product name: blue plate cut-off product (edge polishing) 100mm × 100mm × 1.35mm)

3 measurements

Measuring environment: (temperature 23 ℃, humidity 50% RH)

(1) In FIG. 1, the state before bonding of a glass plate and a test piece in the measurement of wettability is shown. As shown in FIG. 1, the angle was 20 degrees-30 degrees in the state which contacted the glass plate a part of adhesive layer surface of a test piece (adhesive sheet).

(2) Next, the test piece was removed from the test piece, bonded only by its own weight, and the time when the adhesive layer was wetted to the end of the glass plate (distance of 100 mm) was recorded at the same time as the hand was released. The average value measured 3 times was made into the wet time, and the wet time was made into the pass less than 10 second.

<Measurement of adhesive force>

Each produced adhesive sheet was cut into a size of 250 mm in width and 150 mm in length, and the clean acrylic plate (Mitsubishi Rayon Co., Ltd. make, brand name: Acrylite L), which was cut and rubbed and washed with 10 rounds of clean water infiltrated with isopropyl alcohol, was used. The 2 kg roller was rolled on the glass plate and crimped | bonded by the method of 1 reciprocation, and it was set as the sample for adhesive force evaluation. After leaving this evaluation sample for 30 minutes in 23 degreeC x 50% RH measurement environment, the adhesive force [N / 250mm] was measured on the conditions of 300 mm / min of tensile velocity and 180 degree of peel angles using the tensile tester.

Example 1

<Production of Acrylic Polymer>

86 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA), and oxypropylene in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 10 parts by weight of hexaoxypropylene monomethyl ether acrylate having an added mole number of 6 units, 0.2 parts by weight of azobisisobutyronitrile as a polymerization initiator, 139 parts by weight of ethyl acetate, and 46 parts by weight of toluene were added, and nitrogen gas was slowly stirred. Was introduced, and the liquid temperature in the flask was maintained at around 60 ° C to carry out the polymerization reaction for about 3 hours to prepare an acrylic polymer solution (A). The weight average molecular weight of the obtained acrylic polymer was 300,000.

<Preparation of the adhesive sheet using the adhesive composition>

4 parts by weight of isocyanurate of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name "coronate HX") as a crosslinking agent, using 100 parts by weight of the acrylic polymer solution (A) (solid content), 0.015 parts by weight of octyl tin dilaurate (manufactured by Tokyo Fine Chemical Co., Ltd., "OL-1") was added, and the mixture was diluted with toluene so as to have a solid content of 29% by weight, followed by stirring to obtain a pressure-sensitive adhesive composition solution.

Applying the pressure-sensitive adhesive composition solution on a "Lumir S10" manufactured by Toray Industries, Inc., a polyethylene terephthalate (PET) film having a thickness of 38 µm, and removing the solvent by drying at 130 ° C for 30 seconds to form an adhesive layer (thickness 20 µm). Formed. Then, it covered with the release film surface-treated with the mold release agent, cured at 50 degreeC for 1 day, and obtained the adhesive sheet.

Example 2

<Production of Acrylic Polymer>

86 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA), and oxypropylene in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 10 parts by weight of decaoxypropylene monomethyl ether acrylate having an added mole number of 10 units, 0.2 part by weight of azobisisobutyronitrile as a polymerization initiator, 139 parts by weight of ethyl acetate, and 46 parts by weight of toluene, and nitrogen gas while slowly stirring. Was introduced, and the polymerization temperature was performed for about 3 hours while maintaining the liquid temperature in the flask at around 60 ° C to prepare an acrylic polymer solution (B). The weight average molecular weight of the obtained acrylic polymer was 300,000.

<Preparation of the adhesive sheet using the adhesive composition>

The adhesive sheet was obtained like Example 1 except having used 100 weight part (solid content) of the said acrylic polymer solution (B) instead of 100 weight part of acrylic polymer solutions (A).

Example 3

<Production of Acrylic Polymer>

86 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA), and oxypropylene in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 10 parts by weight of pentadecaoxypropylene monomethyl ether acrylate having an added mole number of 15 units, 0.2 parts by weight of azobisisobutyronitrile as a polymerization initiator, 139 parts by weight of ethyl acetate, and 46 parts by weight of toluene were added, and nitrogen was slowly stirred. A gas was introduced, and the polymerization temperature was performed for about 3 hours while maintaining the liquid temperature in the flask at around 60 ° C to prepare an acrylic polymer solution (C). The weight average molecular weight of the obtained acrylic polymer was 310,000.

<Preparation of the adhesive sheet using the adhesive composition>

The adhesive sheet was obtained like Example 1 except having used 100 weight part (solid content) of the said acrylic polymer solution (C) instead of 100 weight part of acrylic polymer solutions (A).

Example 4

<Production of Acrylic Polymer>

72 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA) in a four-necked flask equipped with a stirring vane, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 24 parts by weight of hexaoxypropylene monomethyl ether acrylate having an added mole number of 6 units, 0.2 parts by weight of azobisisobutyronitrile as a polymerization initiator, 139 parts by weight of ethyl acetate, and 46 parts by weight of toluene were added, and nitrogen gas was slowly stirred. Was introduced, the polymerization was carried out for about 3 hours while maintaining the liquid temperature in the flask at around 60 ° C to prepare an acrylic polymer solution (D). The weight average molecular weight of the obtained acrylic polymer was 400,000.

<Preparation of the adhesive sheet using the adhesive composition>

The adhesive sheet was obtained like Example 1 except having used 100 weight part (solid content) of the said acrylic polymer solution (D) instead of 100 weight part of acrylic polymer solutions (A).

Example 5

<Production of Acrylic Polymer>

58 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA) in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 38 parts by weight of hexaoxypropylene monomethyl ether acrylate having an added mole number of 6 units, 0.2 parts by weight of azobisisobutyronitrile as a polymerization initiator, 139 parts by weight of ethyl acetate, and 46 parts by weight of toluene were added, and nitrogen gas was slowly stirred. Was introduced, the polymerization was carried out for about 3 hours while the liquid temperature in the flask was kept at around 60 ° C to prepare an acrylic polymer solution (E). The weight average molecular weight of the obtained acrylic polymer was 560,000.

<Preparation of the adhesive sheet using the adhesive composition>

An adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of the acrylic polymer solution (E) (solid content) was used instead of 100 parts by weight of the acrylic polymer solution (A).

Example 6

<Production of Acrylic Polymer>

28 parts by weight of 2-ethylhexyl acrylate (2EHA), 58 parts by weight of butyl acrylate (BA), 2-hydroxyethyl acryl in a four-necked flask equipped with a stirring vane, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 4 parts by weight of HEA, 10 parts by weight of hexaoxypropylene monomethyl ether acrylate having an added mole number of oxypropylene units, 0.2 parts by weight of azobisisobutyronitrile, 139 parts by weight of ethyl acetate, and toluene 46 as a polymerization initiator. A weight part was added, nitrogen gas was introduced while slowly stirring, the liquid temperature in the flask was maintained at around 60 ° C, and polymerization reaction was performed for about 3 hours to prepare an acrylic polymer solution (F). The weight average molecular weight of the obtained acrylic polymer was 340,000.

<Preparation of the adhesive sheet using the adhesive composition>

An adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of the acrylic polymer solution (F) (solid content) was used instead of 100 parts by weight of the acrylic polymer solution (A).

Example 7

<Preparation of the adhesive sheet using the adhesive composition>

4 weights of isocyanurates of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name "coronate HX") using 100 parts by weight (solid content) of the acrylic polymer solution (A) prepared in Example 1 as a crosslinking agent. Instead of the part, the adhesive sheet was obtained like Example 1 except having used 4 weight part of trimethylol propane / tolylene diisocyanate trimer adduct (The Nippon Polyurethane Co., Ltd. make, brand name "coronate L").

Comparative Example 1

<Production of Acrylic Polymer>

86 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA), and oxypropylene in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 10 parts by weight of dioxypropylene monomethyl ether acrylate having an additional mole number of 2, 0.2 parts by weight of azobisisobutyronitrile, 139 parts by weight of ethyl acetate and 46 parts by weight of toluene as a polymerization initiator, and nitrogen gas while slowly stirring. Was introduced, the polymerization was carried out for about 3 hours while maintaining the liquid temperature in the flask at around 60 ° C to prepare an acrylic polymer solution (G). The weight average molecular weight of the obtained acrylic polymer was 500,000.

<Preparation of the adhesive sheet using the adhesive composition>

An adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of the acrylic polymer solution (G) (solid content) was used instead of 100 parts by weight of the acrylic polymer solution (A).

Comparative Example 2

<Production of Acrylic Polymer>

38 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA) in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 58 parts by weight of dioxypropylene monomethyl ether acrylate having an additional mole number of 2, 0.2 parts by weight of azobisisobutyronitrile, 139 parts by weight of ethyl acetate, and 46 parts by weight of toluene as a polymerization initiator, and nitrogen gas while slowly stirring. Was introduced, and the polymerization temperature was performed for about 3 hours while maintaining the liquid temperature in the flask at around 60 ° C to prepare an acrylic polymer solution (H). The weight average molecular weight of the obtained acrylic polymer was 590,000.

<Preparation of the adhesive sheet using the adhesive composition>

An adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of the acrylic polymer solution (H) (solid content) was used instead of 100 parts by weight of the acrylic polymer solution (A).

Comparative Example 3

<Preparation of the adhesive sheet using the adhesive composition>

4 weights of isocyanurates of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name "coronate HX") using 100 parts by weight (solid content) of the acrylic polymer solution (H) prepared in Comparative Example 2 Instead of the part, the adhesive sheet was obtained like Example 1 except having used 4 weight part of trimethylol propane / tolylene diisocyanate trimer adduct (The Nippon Polyurethane Co., Ltd. make, brand name "coronate L").

Comparative Example 4

<Production of Acrylic Polymer>

19 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA), and oxypropylene in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 77 parts by weight of dioxypropylene monomethyl ether acrylate having an additional mole number of 2, 0.2 parts by weight of azobisisobutyronitrile, 139 parts by weight of ethyl acetate and 46 parts by weight of toluene as a polymerization initiator, and nitrogen gas while slowly stirring. Was introduced, and the polymerization temperature was performed for about 3 hours while maintaining the liquid temperature in the flask at around 60 ° C to prepare an acrylic polymer solution (I). The weight average molecular weight of the obtained acrylic polymer was 640,000.

<Preparation of the adhesive sheet using the adhesive composition>

An adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of the acrylic polymer solution (I) (solid content) was used instead of 100 parts by weight of the acrylic polymer solution (A).

Comparative Example 5

<Preparation of the adhesive sheet using the adhesive composition>

4 weights of isocyanurates of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name "coronate HX") using 100 parts by weight (solid content) of the acrylic polymer solution (I) prepared in Comparative Example 4 Instead of the part, the adhesive sheet was obtained like Example 1 except having used 4 weight part of trimethylol propane / tolylene diisocyanate trimer adduct (The Nippon Polyurethane Co., Ltd. make, brand name "coronate L").

Comparative Example 6

<Preparation of the adhesive sheet using the adhesive composition>

4 weights of isocyanurates of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., product name "coronate HX") as a crosslinking agent, using 100 parts by weight (solid content) of the acrylic polymer solution (G) prepared in Comparative Example 1. Instead of the part, the adhesive sheet was obtained like Example 1 except having used 4 weight part of trimethylol propane / tolylene diisocyanate trimer adduct (The Nippon Polyurethane Co., Ltd. make, brand name "coronate L").

Comparative Example 7

<Production of Acrylic Polymer>

86 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA), and oxypropylene in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 10 parts by weight of trioxypropylene monomethyl ether acrylate having an added mole number of 3, 0.2 parts by weight of azobisisobutyronitrile, 139 parts by weight of ethyl acetate, and 46 parts by weight of toluene as a polymerization initiator, and nitrogen gas while slowly stirring. Was introduced, the polymerization was carried out for about 3 hours while the liquid temperature in the flask was kept at around 60 ° C to prepare an acrylic polymer solution (J). The weight average molecular weight of the obtained acrylic polymer was 600,000.

<Preparation of the adhesive sheet using the adhesive composition>

An adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of the acrylic polymer solution (J) (solid content) was used instead of 100 parts by weight of the acrylic polymer solution (A).

Comparative Example 8

<Preparation of the adhesive sheet using the adhesive composition>

4 weights of isocyanurates of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., product name "coronate HX") as a crosslinking agent, using 100 parts by weight (solid content) of the acrylic polymer solution (J) prepared in Comparative Example 7. Instead of the part, the adhesive sheet was obtained like Example 1 except having used 4 weight part of trimethylol propane / tolylene diisocyanate trimer adduct (The Nippon Polyurethane Co., Ltd. make, brand name "coronate L").

Comparative Example 9

<Production of Acrylic Polymer>

72 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA) in a four-necked flask equipped with a stirring vane, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 24 parts by weight of trioxypropylene monomethyl ether acrylate having an additional mole number of 3, 0.2 parts by weight of azobisisobutyronitrile, 139 parts by weight of ethyl acetate and 46 parts by weight of toluene as a polymerization initiator, and nitrogen gas while slowly stirring. Was introduced, and the liquid temperature in the flask was maintained at around 60 ° C to carry out the polymerization reaction for about 3 hours to prepare an acrylic polymer solution (K). The weight average molecular weight of the obtained acrylic polymer was 610,000.

<Preparation of the adhesive sheet using the adhesive composition>

The adhesive sheet was obtained like Example 1 except having used 100 weight part (solid content) of the said acrylic polymer solution (K) instead of 100 weight part of acrylic polymer solutions (A).

Comparative Example 10

<Preparation of the adhesive sheet using the adhesive composition>

4 weights of isocyanurates of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name "coronate HX") using 100 parts by weight (solid content) of the acrylic polymer solution (K) prepared in Comparative Example 7 Instead of the part, the adhesive sheet was obtained like Example 1 except having used 4 weight part of trimethylol propane / tolylene diisocyanate trimer adduct (The Nippon Polyurethane Co., Ltd. make, brand name "coronate L").

Comparative Example 11

<Production of Acrylic Polymer>

86 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA), and oxypropylene in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 10 parts by weight of polyoxypropylene monomethacrylate (manufactured by Nichiyu Co., Ltd., trade name "Bremer PP-1000"), in which the added mole number of the unit is 4-6, 0.2 part by weight of azobisisobutyronitrile as a polymerization initiator, acetic acid 139 parts by weight of ethyl and 46 parts by weight of toluene were added thereto, nitrogen gas was introduced while stirring slowly, and the polymerization reaction was performed for about 3 hours while maintaining the liquid temperature in the flask at around 60 ° C to prepare an acrylic polymer solution (L). The weight average molecular weight of the obtained acrylic polymer was 370,000.

<Preparation of the adhesive sheet using the adhesive composition>

An adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of the acrylic polymer solution (L) (solid content) was used instead of 100 parts by weight of the acrylic polymer solution (A).

Comparative Example 12

<Production of Acrylic Polymer>

58 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA) in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 38 parts by weight of dioxyethylene monoethyl ether acrylate having an added mole number of 2, 0.2 parts by weight of azobisisobutyronitrile, 139 parts by weight of ethyl acetate, and 46 parts by weight of toluene as a polymerization initiator, and nitrogen gas while slowly stirring. Was introduced, the polymerization was carried out for about 3 hours while the liquid temperature in the flask was kept at around 60 ° C to prepare an acrylic polymer solution (M). The weight average molecular weight of the obtained acrylic polymer was 500,000.

<Preparation of the adhesive sheet using the adhesive composition>

An adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of the acrylic polymer solution (M) (solid content) was used instead of 100 parts by weight of the acrylic polymer solution (A).

Comparative Example 13

<Production of Acrylic Polymer>

38 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA) in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 58 parts by weight of dioxyethylene monoethyl ether acrylate having an additional mole number of 2, 0.2 parts by weight of azobisisobutyronitrile, 139 parts by weight of ethyl acetate and 46 parts by weight of toluene as a polymerization initiator, and nitrogen gas while slowly stirring. Was introduced, the polymerization was carried out for about 3 hours while the liquid temperature in the flask was maintained at around 60 ° C to prepare an acrylic polymer solution (N). The weight average molecular weight of the obtained acrylic polymer was 580,000.

<Preparation of the adhesive sheet using the adhesive composition>

The adhesive sheet was obtained like Example 1 except having used 100 weight part (solid content) of the said acrylic polymer solution (N) instead of 100 weight part of acrylic polymer solutions (A).

Comparative Example 14

<Production of Acrylic Polymer>

19 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA), and oxyethylene in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 77 parts by weight of dioxyethylene monoethyl ether acrylate having an additional mole number of 2, 0.2 parts by weight of azobisisobutyronitrile, 139 parts by weight of ethyl acetate, and 46 parts by weight of toluene as a polymerization initiator, and nitrogen gas while slowly stirring. Was introduced, the polymerization was carried out for about 3 hours while maintaining the liquid temperature in the flask at around 60 ° C to prepare an acrylic polymer solution (O). The weight average molecular weight of the obtained acrylic polymer was 810,000.

<Preparation of the adhesive sheet using the adhesive composition>

The adhesive sheet was obtained like Example 1 except having used 100 weight part (solid content) of the said acrylic polymer solution (O) instead of 100 weight part of acrylic polymer solutions (A).

Example 8

<Production of Acrylic Polymer>

86 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA) in a four-necked flask equipped with a stirring vane, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel, and acrylic acid ( AA) 3 parts by weight, 10 parts by weight of hexaoxypropylene monomethyl ether acrylate having an added mole number of oxypropylene units, 0.2 parts by weight of azobisisobutyronitrile, 139 parts by weight of ethyl acetate, and 46 parts by weight of toluene as a polymerization initiator. Nitrogen gas was introduce | transduced by adding and stirring slowly, the liquid temperature in a flask was kept at 60 degreeC, and superposition | polymerization reaction was performed for about 3 hours, and the acrylic polymer solution (P) was manufactured. The weight average molecular weight of the obtained acrylic polymer was 300,000.

<Preparation of the adhesive sheet using the adhesive composition>

The adhesive sheet was obtained like Example 1 except having used 100 weight part (solid content) of the said acrylic polymer solution (P) instead of 100 weight part of acrylic polymer solutions (A).

Example 9

<Production of Acrylic Polymer>

86 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA) in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler and a dropping funnel, N- 4 parts by weight of vinyl-2-pyrrolidone (NVP), 10 parts by weight of hexaoxypropylene monomethyl ether acrylate having an added mole number of oxypropylene units, 0.2 part by weight of azobisisobutyronitrile as a polymerization initiator, ethyl acetate 139 parts by weight and 46 parts by weight of toluene were added thereto, nitrogen gas was introduced while stirring slowly, and the polymerization temperature was performed for about 3 hours while maintaining the liquid temperature in the flask at around 60 ° C to prepare an acrylic polymer solution (Q). The weight average molecular weight of the obtained acrylic polymer was 300,000.

<Preparation of the adhesive sheet using the adhesive composition>

An adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of the acrylic polymer solution (Q) (solid content) was used instead of 100 parts by weight of the acrylic polymer solution (A).

Example 10

<Production of Acrylic Polymer>

86 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA), methacryl in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. 3 parts by weight of methyl acid (MMA), 10 parts by weight of hexaoxypropylene monomethyl ether acrylate having an added mole number of oxypropylene units, 0.2 parts by weight of azobisisobutyronitrile, 139 parts by weight of ethyl acetate, and toluene as a polymerization initiator. 46 parts by weight was added, nitrogen gas was introduced while stirring slowly, and the polymerization temperature was performed for about 3 hours while maintaining the liquid temperature in the flask at around 60 ° C to prepare an acrylic polymer solution (R). The weight average molecular weight of the obtained acrylic polymer was 300,000.

<Preparation of the adhesive sheet using the adhesive composition>

An adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of the acrylic polymer solution (R) (solid content) was used instead of 100 parts by weight of the acrylic polymer solution (A).

Example 11

<Production of Acrylic Polymer>

21 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 2-hydroxyethyl acrylate (HEA), ethyl acrylate in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, a cooler, and a dropping funnel. (EA) 65 parts by weight, 10 parts by weight of hexaoxypropylene monomethyl ether acrylate having an added mole number of oxypropylene units of 6, 0.2 parts by weight of azobisisobutyronitrile, 139 parts by weight of ethyl acetate, and 46 parts of toluene as polymerization initiators. The part was added, nitrogen gas was introduced while stirring slowly, and the polymerization temperature was performed for about 3 hours while maintaining the liquid temperature in the flask at around 60 ° C to prepare an acrylic polymer solution (S). The weight average molecular weight of the obtained acrylic polymer was 300,000.

<Preparation of the adhesive sheet using the adhesive composition>

An adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of the acrylic polymer solution (S) (solid content) was used instead of 100 parts by weight of the acrylic polymer solution (A).

About the adhesive sheet produced by the Example and the comparative example, wettability and adhesiveness were evaluated by the said evaluation method. The results are shown in Table 1 and Table 2.

The symbol in the said Table 1, Table 2 shows the following commercial items.

C / HX: Nippon Polyurethane Co., Ltd. brand name "coronate HX" (isocyanurate / hexamethylene diisocyanate trimer adduct)

C / L: Nippon Polyurethane Co., Ltd. brand name "coronate L" (trimethylolpropane / tolylene diisocyanate trimer adduct)

From the above result, in the adhesive sheet of the Example which uses the adhesive composition containing the acrylic polymer and crosslinking agent which contain polyoxypropylene monoalkyl ether (meth) acrylate whose addition mole number of an oxypropylene unit is four or more as a monomer component, it is favorable. It was confirmed that wettability was obtained.

On the other hand, Comparative Examples 1 to 10 containing polyoxypropylene monoalkyl ether (meth) acrylate having an added molar number of oxypropylene units of less than 4 as monomer components, Comparative Example 11 whose terminal is a hydroxyl group instead of an alkyl ether, and the main skeleton is oxyethylene It was confirmed that all of Comparative Examples 12-14 which are a skeleton and do not have an oxypropylene skeleton are inferior to wettability.

Claims (8)

The adhesive composition containing the acryl-type polymer containing the polyoxypropylene monoalkyl ether (meth) acrylate whose addition mole number of an oxypropylene unit is four or more as a monomer component, and a crosslinking agent. The method of claim 1,
The acrylic polymer is 30% by weight to 94.9% by weight of an alkyl (meth) acrylate having an alkyl group having 4 to 18 carbon atoms, and 5% by weight of polyoxypropylene monoalkyl ether (meth) acrylate having an added mole number of oxypropylene units of 4 or more. Pressure-sensitive adhesive composition containing 40 to 40% by weight and 0.1 to 10% by weight of the functional group-containing monomer as a monomer component. The method of claim 2,
The adhesive composition which the said acrylic polymer further contains another copolymerizable monomer as content of a monomer component in 20 weight% or less. The method of claim 1,
The polyoxypropylene monoalkyl ether (meth) acrylate whose addition mole number of the said oxypropylene unit is four or more is hexaoxypropylene monomethyl ether (meth) acrylate, The adhesive composition characterized by the above-mentioned. The method of claim 1,
The pressure-sensitive adhesive composition containing 1 part by weight to 10 parts by weight of the crosslinking agent based on 100 parts by weight of the acrylic polymer. The method of claim 1,
The crosslinking agent is an isocyanate-based crosslinking agent, characterized in that the pressure-sensitive adhesive composition. The pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition of claim 1. The adhesive sheet which forms the adhesive layer of Claim 7 on a base material.

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