JP2001342448A - Coating type tacky material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating type tacky material capable of forming a film excellent in strength and tackiness and exhibiting excellent adhesiveness and persistency of adhesive force. SOLUTION: This coating type tacky material comprises (i) 10-100 wt.% hydrogenated block copolymer, comprising a vinyl-aromatic polymer block (A) containing >50 wt.% vinyl-aromatic compound and a conjugated diene-based polymer block B, in which 1,2-vinyl bond content and 3,4-vinyl bond content of the conjugated diene are 60-85% based on the conjugated diene and >=80% of a conjugated diene part of the block copolymer (a) is hydrogenated, having 35-70 wt.% content of bound vinyl-aromatic compound in the copolymer and (ii) 90-0 wt.% tackiness-imparting agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating type adhesive containing a hydrogenated block copolymer having a specific structure and a tackifier.

[0002]

2. Description of the Related Art Conventionally, a coating composition has been prepared by dissolving a hydrogenated product of a conjugated diene-based block copolymer and a tackifier in a solvent, and has been used as a primer, an adhesive and the like. For example, JP-A-1-306224 discloses that a primer is prepared by dissolving a hydrogenated styrene-based thermoplastic block polymer, a (hydrogenated) rosin ester resin and / or a (hydrogenated) petroleum-based tackifier and a plasticizer in a solvent. It is disclosed that the composition is applied to the adhesive bonding interface of a lens material made of plastic. JP-A-5-247424 discloses a styrene-butadiene-styrene block copolymer, a tackifier, a carboxylated styrene-ethylene
It is possible to dissolve and disperse the butylene / styrene block copolymer and further the conductive fine particles in a solvent having a solubility parameter value of 9 to 9.5, and use this for adhesion between the anisotropic conductive film and the circuit member. It has been disclosed.

[0003] However, conventional coating-type compositions using these hydrogenated conjugated diene block copolymers are insufficient in the strength and tackiness of the formed film, and as a result, when used as a primer, for example, Cohesive failure and interfacial peeling are likely to occur, and are insufficient in terms of adhesiveness and durability of adhesive strength, and improvements have been required.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a coating type pressure-sensitive adhesive material which can form a coating film having excellent strength and tackiness and which exhibits excellent adhesiveness and continuous adhesive strength. It is in.

[0005]

According to the present invention, there is provided a coating type pressure-sensitive adhesive having the following constitution, and the above object of the present invention is achieved. 1. (A) a copolymer comprising a vinyl aromatic polymer block A containing more than 50% by weight of a vinyl aromatic compound and a conjugated diene polymer block B containing more than 50% by weight of a conjugated diene compound; Block copolymer in which the content of the bound vinyl aromatic compound is 35 to 70% by weight and the 1,2-vinyl bond and the 3,4-vinyl bond of the conjugated diene are 60 to 85% of the conjugated diene (A)
And 10 to 100 parts by weight of a hydrogenated block copolymer obtained by hydrogenating 80% or more of the conjugated diene portion of (a) and (b) 90 to 0 parts by weight of a tackifier (where (a) and (b) (The total amount is 100 parts by weight).

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. The (a) hydrogenated block copolymer used in the present invention is a vinyl aromatic compound-based polymer block A
And a conjugated diene-based polymer block B. The block copolymer (a) is obtained by hydrogenating a conjugated diene component. The vinyl aromatic compound-based polymer block A of the block copolymer (a) has a structure of a homopolymer of a vinyl aromatic compound or a vinyl aromatic compound containing 50% by weight, preferably 70% by weight or more. It has the structure of a copolymer of an aromatic compound and another copolymerizable monomer, preferably a conjugated diene compound. The conjugated diene polymer block B has a structure of a homopolymer of a conjugated diene compound or a structure in which another monomer such as a vinyl aromatic compound is copolymerized in less than 50% by weight (more than 50% by weight of the conjugated diene compound). have.

Preferred block structures of the block copolymer (a) include the following structures. (I) A structure represented by (AB) nA type (n is an integer of 1 to 10). (II) (AB) m type (m is an integer of 2 to 10)
Structure indicated by. (III) ((AB) x) y-M type (M is Si or Sn
And the like, y is an integer of 2 to 4 in valence of the coupling agent residue, x is an integer of 1 to 10, preferably 1
Or 2. ). Here, A represents the above-mentioned vinyl aromatic compound-based polymer block A, and B represents the conjugated diene polymer block B. Further, the vinyl aromatic compound block A at the end may have a relatively short conjugated diene polymer block B.

The above vinyl aromatic compounds include styrene, α-methylstyrene, p-methylstyrene, t-butylstyrene, divinylbenzene, N, N-dimethyl-
p-aminoethylstyrene, 2,4-dimethylstyrene, N, N-diethyl-p-aminoethylstyrene,
2,4-dimethylstyrene, vinylnaphthalene, vinylanthracene, etc., among which styrene, α-
Methylstyrene is preferred.

The conjugated diene compound includes:
1,3-butadiene, isoprene, 2,3-dimethyl-
1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene,
One or more kinds of 4,5-dimethyl-1,3-octadiene, chloroprene and the like can be mentioned.
3-Butadiene and isoprene are preferred.

In the vinyl aromatic compound polymer block A, the other monomers copolymerizable with the vinyl aromatic compound are mainly the above-mentioned conjugated diene compounds, and among them, 1,3-butadiene and isoprene are preferred.

The content of the bound vinyl aromatic compound in the block copolymer (a) is 35 to 70% by weight, preferably 40 to 60% by weight. If the proportion of the vinyl aromatic compound is less than 35% by weight, the strength of the coating film formed from the coating type pressure-sensitive adhesive of the present invention decreases, and if it exceeds 70% by weight, the adhesion of the coating film decreases, which is not preferable. .

In the block copolymer (a), when the conjugated diene compound is 1,3-butadiene, the bonding structure of the conjugated diene compound is 1,4- and 1,2-.
-(Vinyl) bond, and in the case of isoprene, 1,4
-, 1, 2-, 3, 4- bonds (in the present specification,
Both 1,2- and 3,4-bonds are referred to as vinyl bonds). The total content of 1,2- and 3,4-vinyl bonds in the conjugated diene polymer block B of the block copolymer (a) is 60 to 85%, preferably 65 to 85%.
It is. When the total amount of the vinyl bond content is less than 60%,
It is not preferable that the adhesion of the coating film decreases, and if it exceeds 85%, the adhesion of the coating film decreases.

(A) The hydrogenated block copolymer is obtained by hydrogenating the conjugated diene component of the block copolymer (a). The hydrogenation rate of the conjugated diene portion is 80% or more, more preferably 85% or more, and further preferably 90% or more.
% Or more. If the hydrogenation rate is less than 80%, the heat resistance of the coating film formed from the coating type pressure-sensitive adhesive of the present invention is undesirably reduced. Further, the weight average molecular weight (in terms of polystyrene by the GPC method) of (a) the hydrogenated block copolymer is preferably from 5,000 to 1,000,000, and more preferably from 10,000 to 500,000. Range.

(A) The amount of the hydrogenated block copolymer used is determined by the total amount of the coating type pressure-sensitive adhesive of the present invention (excluding the solvent).
10 to 100 parts by weight, preferably 1 to 100 parts by weight with respect to 0 parts by weight.
0 to 90 parts by weight. If the amount of the hydrogenated block copolymer is less than 10 parts by weight, it is difficult to form a coating film. If the content is within the range, two or more hydrogenated block copolymers may be used in combination.

Further, (a) as the hydrogenated block copolymer component, the hydrogenated block copolymer may contain at least one selected from an acid anhydride group, a carboxyl group, a hydroxyl group, an amino group, an isocyanate group and an epoxy group. A modified hydrogenated block copolymer having the following functional group may be used. Further, an unmodified hydrogenated block copolymer and a modified hydrogenated block copolymer may be used in combination in any ratio as the component (A).

(B) Used in the coating type adhesive of the present invention
As the tackifier, one or two or more kinds of known tackifiers can be used. For example, terpene resins, terpene phenol resins, cumarone resins, rosin ester resins, aromatic petroleum resins, hydrocarbon resins and the like can be mentioned.

The proportion of (a) the hydrogenated block copolymer and (b) the tackifier is in the range of (a) 10 to 100 parts by weight, preferably 10 to 90 parts by weight of the hydrogenated block copolymer.
The amount of the tackifier is 90 to 0 parts by weight, preferably 90 to 10 parts by weight based on parts by weight (the total amount of both is 100 parts by weight). In the present invention, (b) the tackifier may not be used, but by using it, the tackiness of the formed coating film is increased and the adhesiveness is improved.
(B) If the tackifier is used in an amount exceeding 90 parts by weight ((a) the amount of the hydrogenated block copolymer used is 10 parts by weight or less), it becomes difficult to form a coating film.

The pressure-sensitive adhesive of the present invention includes a leveling agent, a thickener, a coloring inhibitor, an ultraviolet absorber, a coupling agent, an antistatic agent, inorganic fine particles, organic fine particles, pigments, conductive particles, softener, liquid rubber , A liquid resin, an antioxidant, a heat stabilizer, a light stabilizer, a rubbery polymer, a thermoplastic resin and the like can be blended within a range that does not impair the achievement of the object of the present invention.

In the present invention, a coating type adhesive is prepared by dissolving and dispersing the above components in a solvent. Examples of the solvent include ketones, alcohols, esters, ethers, furans, halogen compounds, aromatic hydrocarbons,
Fatty acid hydrocarbons and the like. Above all, those having a boiling point in the range of ordinary temperature to 200 ° C. are preferred. Specifically, acetone, methyl ethyl ketone, methyl isobutyl ketone;
Ketones such as cyclohexanone, isophorone, acetylacetone and acetophenone; alcohols such as cyclohexanol; esters such as ethyl acetate, butyl acetate, acetic acid-3-methoxybutyl and butyl acetoacetate; ethyl glycol monobutyl ether, diethylene glycol monoethyl ether; Ethers such as diethylene glycol monomethyl ether; furans such as tetrahydrofuran; methyl chloroform, dichloroethane, 1,1,
Halogen compounds such as 2-trichloroethane, 1,2,3-trichloropropane and trichloroethylene; benzene, toluene, xylene, styrene, kerosene, mineral spirit, n-hexane, n-heptane, n-octane, gasoline, cyclohexane, etc. Aromatic or aliphatic hydrocarbons.

The amount of these solvents used is not particularly limited, but is preferably 20 to 2000 parts by weight, more preferably 50 to 1000 parts by weight, per 100 parts by weight of the total of the hydrogenated block copolymer and the tackifier. Parts by weight, particularly preferably 50 to 500 parts by weight.

The coating type pressure-sensitive adhesive of the present invention can be applied to the surface to be coated by brush coating, dip coating, air knife coating,
Curtain coating method, roller coating method, bar coating method,
It can be applied by a gravure coating method or an extrusion coating method.

After coating, the coating is formed on the surface to be coated by heating and drying. The thickness of the coating film is appropriately set depending on the type of the object to be coated, but is usually applied so as to have a thickness of 0.5 to 500 μm.

The pressure-sensitive adhesive of the present invention can be used as a primer or an adhesive, and can be used for various base materials such as various thermoplastic resins, various thermosetting resins, various vulcanized rubbers, various thermoplastic elastomers, and metals such as steel sheets. The above-mentioned functions can be exhibited by forming a coating film by coating on the surface of a plate or a glass plate.

[0024]

EXAMPLES The present invention will be specifically described below with reference to examples, but it should be understood that the present invention is not construed as being limited to the examples. The percentages in the examples are on a weight basis unless otherwise specified. Various chemical compositions and evaluations in the examples are values and evaluations measured as follows. (1) Bound vinyl aromatic compound content It was measured by infrared analysis based on the absorption of a phenyl group at 679 cm ^-1 . (2) Vinyl bond content of conjugated diene Calculated by Morero method using infrared analysis. (3) Hydrogenation ratio Using carbon tetrachloride as a solvent, the hydrogenation ratio was calculated from a ¹ H-NMR spectrum at 90 MHz. (4) Weight average molecular weight Using tetrahydrofuran as a solvent, the weight average molecular weight was determined by gel permeation chromatography (GPC) at 38 ° C in terms of polystyrene. (5) Measurement of adhesive strength 100 parts by weight of the hydrogenated styrene-butadiene block copolymer and the tackifier were dissolved in 400 parts by weight of toluene to prepare an adhesive solution. This was separately extruded into a polypropylene resin film (width 20m).
m, length 250 mm, thickness 0.2 mm), dry in an oven at a temperature of 120 ° C. for 3 minutes, make the adhesive thickness about 25 μm, preheat the adhesive surface with a drier, and separately use an injection molding method 80 mm on a polypropylene resin plate (width 20 mm, length 250 mm, thickness 2 mm)
It was press-bonded with a roll having a load of 0 g and left for 24 hours. Thereafter, according to the JISZ-0237 method, a peel angle of 180 degrees,
The adhesive strength was measured under the condition of a peeling speed of 300 mm / min. The adhesive strength was measured in the same manner after the durability test at a temperature of 120 ° C. for 250 hours.

The various components used in the examples, comparative examples, and evaluation formulations are as follows. (A) Component hydrogenated styrene-butadiene block copolymer e1
Table 1 shows the microstructures and hydrogenation ratios of A to A-7. (B) Component Clearon P140 (manufactured by Yasuhara Chemical Co., Ltd., substance name: hydrogenated terpene resin)

[0026]

[Table 1]

In Table 1, ST represents styrene, and BD represents butadiene.

The results of the physical property evaluation are shown in Tables 2 and 3.

[0029]

[Table 2]

[0030]

[Table 3]

From the results of Examples 1 to 5 shown in Table 2, it can be seen that the coating type pressure-sensitive adhesive of the present invention is excellent in the balance between the pressure-sensitive adhesive strength and the durability of the pressure-sensitive adhesive force. On the other hand, with respect to the comparative examples shown in Table 3, Comparative Examples 1 to 3 had the adhesive strength because the hydrogenated block copolymer was out of the range of the present invention, and Comparative Example 4 had the composition outside the range. , Poor adhesion persistence.

[0032]

According to the present invention, a coating film having excellent strength and tackiness can be formed from the coating type pressure-sensitive adhesive material of the present invention, and excellent adhesiveness and continuous adhesive strength can be exhibited. Therefore, adhesion of various materials,
It is suitably used in a wide range of fields relating to bonding.

Claims (1)

[Claims] (1) 50% by weight of a vinyl aromatic compound
A conjugated diene-based polymer block B containing more than 50% by weight of a vinyl aromatic polymer block A containing more than 50% by weight of the conjugated diene compound. 35 to 70% by weight, and 80% or more of the conjugated diene portion of the block copolymer (a) in which the 1,2-vinyl bond and the 3,4-vinyl bond of the conjugated diene are 60 to 85% of the conjugated diene. Is hydrogenated, 10 to 100 parts by weight of a hydrogenated block copolymer, and (b) 90 to 0 parts by weight of a tackifier (here,
(A) The total amount of (a) and (b) is 100 parts by weight).