JPH11172215A - Adhesive composition containing hydrocarbon resin tackifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive having good initial adhesive strength, adhesive strength and holding power, and a hot melt adhesive showing good heat resistance and good adhesiveness over a wide temperature range. I do. (A) At least one base polymer selected from an elastomer and a thermoplastic resin,
(B) Monoolefin and carbon number 4 or more as tackifiers
Softening point of 60 to 1 obtained by cationic polymerization of the chain conjugated diene of No. 5 with an acidic metal halide catalyst.
In an adhesive composition containing a hydrocarbon resin at 30 ° C., the hydrocarbon resin is polymerized by using a cycloolefin alone or a hydrocarbon mixed solvent containing 5% by weight or more of cycloolefin as a polymerization solvent. Use the one obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pressure-sensitive adhesive composition containing a specific hydrocarbon resin as a tackifier and containing an elastomer and / or a thermoplastic resin as a base polymer. The adhesive compositions of the present invention exhibit improved adhesive properties and are particularly useful as pressure sensitive adhesives and hot melt adhesives.

[0002]

2. Description of the Related Art Conventionally, as an adhesive or a hot melt adhesive, a composition in which a tackifier is blended with a base polymer such as an elastomer or a thermoplastic resin has been used.
For example, pressure-sensitive adhesive tapes or labels such as pressure-sensitive adhesive tapes, kraft tapes, and price labels use a pressure-sensitive adhesive obtained by compounding a tackifier with an elastomer. Natural rubber, polyisoprene, styrene-butadiene rubber (SBR),
Styrene-isobutylene-based block copolymers and hydrides thereof, styrene-butadiene-based block copolymers and hydrides thereof are used, and as a tackifier, natural resins such as polyterpene resins and rosin esters and petroleum-based resins are used. Hydrocarbon resins are used. on the other hand,
Hot melt adhesives widely used for bonding paper, wood, metal, plastic, etc. include thermoplastic resins such as polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and styrene-
A thermoplastic elastomer such as an isoprene-based block copolymer or a styrene-butadiene-based block copolymer is blended with a petroleum hydrocarbon resin as a tackifier.

[0003] Among petroleum hydrocarbon resins, a hydrocarbon resin obtained by cationic polymerization of a monoolefin and a conjugated diene having 4 to 5 carbon atoms using an acidic metal halide catalyst is blended as a tackifier. The pressure-sensitive adhesive composition is particularly excellent in initial adhesive strength, and the hot-melt adhesive containing the same hydrocarbon resin has good heat resistance and exhibits good adhesiveness over a relatively wide temperature range. Have. As a specific example of such a hydrocarbon resin tackifier, a monomer mixture comprising isoprene, an aromatic monoolefin and an aliphatic monoolefin is cationically polymerized using an aluminum halide-based catalyst in the presence of a solvent. And a monomer mixture comprising 1,3-butadiene, styrene, cyclopentene and 1,3-butadiene in the presence of a solvent. And hydrocarbon resins obtained by cationic polymerization in the presence of an aluminum halide-based catalyst (JP-A-60-118777).

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an adhesive comprising a hydrocarbon resin tackifier obtained by cationic polymerization of a monoolefin and a conjugated diene as described above using an acidic metal halide catalyst. It is an object of the present invention to provide a pressure-sensitive adhesive composition exhibiting even more excellent pressure-sensitive adhesive properties as compared with an adhesive composition. More specifically, (1) a pressure-sensitive adhesive composition having excellent initial adhesive strength together with good adhesive strength and holding power, and (2) good heat resistance, over a relatively wide temperature range. To provide a hot-melt adhesive composition exhibiting excellent adhesiveness.

The present inventors have conducted intensive studies on hydrocarbon resin tackifiers. As a result, when cationic polymerization of a conjugated diene and a monoolefin was carried out using an aluminum chloride catalyst, cycloolefin or cycloolefin was used as a polymerization solvent. By using a hydrocarbon mixed solvent containing 5% by weight or more, a hydrocarbon resin obtained as a result of polymerization was found to be much more excellent as a tackifier, and the present invention was completed based on this finding.

[0006]

Thus, according to the present invention, at least one base polymer selected from the group consisting of (a) an elastomer and a thermoplastic resin is added to (b) a monoolefin and a carbon as a tackifier. An adhesive composition comprising a hydrocarbon resin having a softening point of 60 to 130 ° C. obtained by cationic polymerization of a chain conjugated diene of Formulas 4 to 5 using an acidic metal halide catalyst. In addition, there is provided a pressure-sensitive adhesive composition characterized in that the above polymerization is carried out using cycloolefin or a hydrocarbon mixed solvent containing 5% by weight or more of cycloolefin as a polymerization solvent.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The adhesive composition of the present invention comprises:
(A) at least one base polymer selected from elastomers and thermoplastic resins, and (b) a polymerization solvent comprising cycloolefin or a hydrocarbon mixed solvent containing 5% by weight or more of cycloolefin as a tackifier. And a hydrocarbon resin having a softening point of 60 to 130 ° C. obtained by cationic polymerization of a monoolefin and a conjugated diene having 4 to 5 carbon atoms in the presence of an acidic metal halide catalyst.

Hydrocarbon Resin Tackifier The hydrocarbon resin used as a tackifier in the present invention is prepared by using a cycloolefin alone or a hydrocarbon mixed solvent containing 5% by weight or more of a cycloolefin as a polymerization solvent to form an acidic halogen. A hydrocarbon resin having a softening point of 60 to 130 ° C. obtained by cationically polymerizing a monoolefin and a conjugated diene having 4 to 5 carbon atoms in the presence of a metal fluoride catalyst.

[0009] The polymerization solvent used for the production of the hydrocarbon resin is a cycloolefin alone or a mixed solvent of a cycloolefin and another hydrocarbon. Specific examples of the cycloolefin include cyclohexene, methylcyclohexene, cyclopentene, methylcyclopentene and the like, and among them, cyclohexene and cyclopentene are preferable.

Specific examples of the hydrocarbon mixed with the cycloolefin include pentane, hexane, heptane,
Examples thereof include aliphatic hydrocarbons such as cyclopentane, cyclohexane, isopentane, and methylpentane; and aromatic hydrocarbons such as benzene, toluene, and xylene. In the present invention, any of them can be used. However, in consideration of the problem of environmental pollution, it is preferable to avoid aromatic hydrocarbons and use aliphatic hydrocarbons. Even when an aromatic hydrocarbon is not used as a solvent, generation of a large amount of gel can be avoided and a hydrocarbon resin having an excellent hue can be obtained.

The mixing ratio of cycloolefin to other hydrocarbons in the mixed solvent must be such that the cycloolefin content is at least 5% by weight. If the cycloolefin content is less than 5% by weight, the gel suppressing effect and the hue improving effect will be insufficient. Good results are also obtained when only cycloolefin is used as the polymerization solvent. The amount of the solvent to be used is usually 20 to 1,000 parts by weight, preferably 50 to 50 parts by weight, per 100 parts by weight of the monomer containing the monoolefin and the chain conjugated diene having 4 to 5 carbon atoms except for the cycloolefin.
５００500 parts by weight.

The monomer composition used for the polymerization for producing the above-mentioned hydrocarbon resin is a mixture of a monoolefin and a chain conjugated diene having 4 to 5 carbon atoms. Preferred specific examples of the chain conjugated diene having 4 to 5 carbon atoms include 1,3-pentadiene, isoprene, and 1,3-butadiene.
Specific examples of the monoolefin include chain monoolefins such as butenes, pentenes, methylbutenes, methylpentenes, and diisobutylene; aromatic monoolefins such as styrene and methylstyrene; and cyclopentene, methylcyclopentene, and cyclohexene. And cyclic monoolefins such as methylcyclohexene.

The ratio of the monoolefin except the cycloolefin to the chain conjugated diene having 4 to 5 carbon atoms is usually 94%.
/ 6 to 15/85 (weight ratio). A typical monomer mixture containing a monoolefin and a conjugated diene having 4 to 5 carbon atoms in this ratio is generally obtained as a naphtha cracking fraction at -20 to + 60 ° C or, if desired, various olefins can be added to this fraction. It is obtained by combining the unsaturated hydrocarbon fractions. Such commercially available monomer mixtures usually contain significant amounts of saturated hydrocarbons, such as butanes, pentanes, cyclopentane, etc.
The presence of these components does not interfere with the purpose of the present invention. Further, as long as the effects of the present invention are not substantially impaired, cyclopentadiene, a dimer thereof, a co-dimer of cyclopentadiene and a chain conjugated diene, and the like may be contained. It is preferable that a pentadiene-based monomer or the like is not substantially contained in the monomer mixture because it reduces the hue of the hydrocarbon resin.

The acidic metal halide catalyst used in the present invention is a Friedel-Crafts type catalyst, which is in a gaseous or solid state at room temperature. A typical example is a metal fluoride such as aluminum, boron or iron. Chloride, bromide and iodide, among which aluminum halides such as aluminum chloride and aluminum bromide are preferred. Aluminum halide is usually 5-
It is used as particles of 200 mesh size, but is not particularly limited. The amount of the catalyst used is usually based on the weight of the monomer.
0.1 to 10% by weight.

It is preferred that the acidic metal halide polymerization catalyst is brought into contact with a monocyclic monoolefin before polymerization. By the contact treatment with the monocyclic monoolefin, the effect of the present invention of preventing the formation of a gel and obtaining a resin having an excellent hue can be further enhanced. As the monocyclic monoolefin to be brought into contact with the acidic metal halide catalyst, a cyclic monoolefin having 5 to 6 carbon atoms is preferable, and specific examples thereof include cyclopentene, methylcyclopentene and cyclohexene, and among them, cyclopentene and cyclohexene are preferred. preferable. The amount of the monocyclic monoolefin contacted with the acidic metal halide catalyst is preferably at least 5 times (weight ratio) the amount of the catalyst.

The polymerization operation can be carried out by a known method,
An ordinary method of adding a solvent and a catalyst to a reactor in advance and adding a polymerization monomer may be used. The mixed solvent may be prepared in a predetermined ratio in advance into the reactor, or may be prepared by mixing both in the reactor. The polymerization temperature is usually
The temperature ranges from 20 ° C to + 100 ° C, preferably from 0 to + 80 ° C. The obtained polymer is treated by a conventional method and dried.

The hydrocarbon resin thus obtained is ASTM
JI having a Gardner chromaticity of 6 or less as measured by D-1544-63T, a number average molecular weight of 500 to 3,000, and 60 to 130C, preferably 70 to 120C.
It has a softening point specified in SK-2531 and is soluble in aliphatic and aromatic hydrocarbons such as pentane, hexane, benzene, toluene, xylene, chloroform, carbon tetrachloride or halogenated hydrocarbon solvents. And a resinous polymer having a low melt viscosity.

Elastomer and Thermoplastic Resin As the base polymer of the adhesive composition of the present invention, at least one selected from elastomers and thermoplastic resins is used. Elastomers and thermoplastics include those elastomers and thermoplastics used in the preparation of adhesive compositions in combination with conventional hydrocarbon resin tackifiers. The preferred base polymer used in the preparation of the adhesive composition used as a pressure-sensitive adhesive is an elastomer. As an elastomer,
Examples thereof include a conjugated diene rubber and a thermoplastic elastomer composed of an aromatic monoolefin polymer block and a conjugated diolefin polymer block.

Examples of the conjugated diene rubber include natural rubber, styrene-butadiene copolymer (SBR), synthetic polyisoprene rubber, polybutadiene rubber and the like, and usually have a Mooney viscosity of 20 to 100, preferably 30 to 80.
Is used. Of these, natural rubber and SBR are preferred. In the case of SBR, the amount of bound styrene is usually 15 to 55% by weight, preferably 20 to 50% by weight, and the number average molecular weight is 100,000 to 1,000,000.
0, preferably 200,000 to 500,000 random copolymers.

As the thermoplastic elastomer comprising an aromatic monoolefin polymer block and a conjugated diolefin polymer block, the thermoplastic elastomer represented by the general formula (AB) _n or (AB)
_n-1 A (where A is substantially an aromatic monoolefin polymer block, B is substantially a conjugated diolefin polymer block, and n is an integer from 2 to 10) Olefin polymer block content 10-7
0% by weight, preferably 10-55% by weight and an average molecular weight of 25,000-500,000, preferably 40,000.
0 to 200,000 block copolymers.

Specific examples of the aromatic monoolefin constituting the block copolymer include styrene, α-methylstyrene, vinyltoluene and the like, and usually styrene is used. Further, specific examples of the conjugated diolefin include 1,3-butadiene, isoprene, 1,3-pentadiene and the like. Specific examples of the block copolymer include, for example, a styrene-isoprene-based block copolymer, a styrene-butadiene-based block copolymer,
And hydrogenated products thereof.

Further, such a block copolymer includes a copolymer containing a small amount of an aromatic monoolefin unit in a gradually increasing ratio from one end to the other end of the conjugated diene block as a “substantial conjugated diolefin polymer block”. So-called “tapered block copolymer”. In addition, a “tapered block copolymer” containing a copolymer containing a small amount of a conjugated diene unit in a ratio that gradually increases from one end to the other end of the aromatic monoolefin block as a “substantial aromatic monoolefin polymer block” Is also included. Further, if necessary, an AB type block copolymer may be appropriately blended. Each of these block copolymers is a known substance, and is a known method using a lithium-based initiator, for example, JP-B-36-19286, JP-B-40-23798.
No., JP-B-43-17979, JP-B-43-2394
It is manufactured according to the method described in the item.

The base polymer used for preparing the adhesive composition used as a hot melt adhesive includes a thermoplastic resin; styrene-butadiene block copolymer, styrene-isoprene block copolymer, and the like. Thermoplastic elastomers. Examples of the thermoplastic resin include polyethylene; ethylene copolymers such as ethylene-vinyl acetate copolymer and ethylene-ethyl acrylate copolymer; polyamide; polyester; and the like. Polymers are preferred.

Among such ethylene polymers, ethylene copolymers are preferred. Specific examples of the comonomer constituting the copolymer include vinyl acetate, vinyl propionate,
Unsaturated esters such as ethyl acrylate, butyl acrylate, methyl methacrylate and ethyl methacrylate; unsaturated acids such as acrylic acid and methacrylic acid; Particularly, an ethylene-unsaturated ester copolymer having an unsaturated ester content of 10 to 50% by weight and a melt index of 0.5 to 2,500 is best.

Adhesive composition The adhesive composition of the present invention comprises at least one base polymer selected from the above-mentioned elastomers and thermoplastic resins and the above-mentioned hydrocarbon resin tackifier. And is prepared by blending The proportions of the base polymer and the hydrocarbon resin tackifier can vary depending on the desired use of the adhesive composition, but generally the base polymer 10
5 to 300 parts by weight, preferably 40 to 200 parts by weight, of the hydrocarbon resin tackifier is added to 0 parts by weight.

Other tackifiers and various additives can be blended according to the intended use within the range that does not essentially hinder the properties of the target adhesive composition. For example, a process oil, a softener such as polybutene, a plasticizer, an antioxidant, a filler, and the like are added. In the hot-melt adhesive composition, waxes such as paraffin wax, microcrystalline wax, and polyethylene wax, which are generally used, can be added at a ratio of 5 to 500 parts by weight based on 100 parts by weight of the base polymer.

The adhesive composition of the present invention is produced according to a method similar to that of a conventional adhesive composition. For example, in the case of a pressure-sensitive adhesive composition, each compounded component can be stirred and mixed in the presence of a solvent such as toluene to form a pressure-sensitive adhesive solution, or a hydrocarbon resin tackifier previously emulsified in a base elastomer latex. Can be mixed with stirring to form an adhesive emulsion. These pressure-sensitive adhesive solutions or pressure-sensitive adhesive emulsions are usually uniformly coated on a desired substrate using a coating machine, dried in an oven, and then wound up to produce various pressure-sensitive adhesive tapes or pressure-sensitive label products. Is done. In the case of a hot-melt adhesive composition, the respective components are simultaneously charged into a melting pot or sequentially from those having a low melt viscosity, and then heated and melt-mixed at 100 to 200 ° C., and then a block, a rod, and a powder are formed. It can be processed into a suitable shape such as a film, a sheet, or the like, or can be produced continuously using a single-screw or twin-screw extruder.

[0028]

The present invention will be described more specifically with reference to the following examples. Parts and% in Examples and Comparative Examples
Unless otherwise specified, weight is based on weight. Polymerization Example 1 (Preparation of Hydrocarbon Resin A) 1.0 part of aluminum chloride was placed in a SUS autoclave,
And 31.1 parts of cyclopentene and cyclopentane 5
A mixed solvent prepared by mixing 7.7 parts was added, and the mixture was stirred to maintain the temperature of the system at 60 ° C. for 10 minutes.

Next, 111.2 parts of a monomer mixture having the following composition (the total amount of 1,3-pentadiene, cyclopentene and diisobutylene was 100 parts) was gradually and continuously added to the above solution over 60 minutes. Was added. Monomer mixture 1,3-pentadiene 42.8 parts by weight 38.5% Cyclopentene 13.2 parts by weight 11.9% Diisobutylene 44.0 parts by weight 39.6% C _4-6 unsaturated hydrocarbon 3.4 Parts by weight 3.1% C _4-6 saturated hydrocarbon 7.8 parts by weight 7.0%

Since the temperature of the system rises due to heat generated by the reaction, the heating temperature was adjusted to maintain the internal temperature at 70 ° C. After completion of the addition, the polymerization system was maintained at 70 ° C., and the mixture was further stirred for 10 minutes. Then, an equal volume mixture of methanol and 28% aqueous ammonia was added to decompose aluminum chloride. The catalyst particles deactivated by the decomposition were removed by filtration, the filtrate was transferred to a glass flask, and heated while blowing in nitrogen to distill off unreacted hydrocarbons, and then heated to 240 ° C. . Next, saturated steam was blown into the system to remove the oily polymer generated by the polymerization reaction, and after confirming that almost no oil layer was present in the distillate, the blowing of steam was stopped to melt the residue. Was taken out and cooled to room temperature to obtain a yellow resinous substance (hydrocarbon resin A).

With respect to the obtained hydrocarbon resin A, the resin yield (1,3- in the cycloolefin and monomer mixture)
Yield based on the total weight of pentadiene, cyclopentene, styrene and diisobutylene), softening point (JIS K-
Weight-average molecular weight and number-average molecular weight (weight-average molecular weight and number-average molecular weight are measured by gel permeation chromatography and converted to standard polystyrene), and Gardner chromaticity (ASTM) D-1544-63T
And expressed as a measured value for a solution obtained by dissolving the resin in an equal amount of toluene. ). Table 1 shows the results.

Polymerization Examples 2 to 6 (Preparation of Hydrocarbon Resins BF) The solvents and monomer mixtures shown in Table 1 were used, and the other operations were performed in the same manner as in Polymerization Example 1 to obtain hydrocarbon resins BF. F was obtained.

[0033]

[Table 1]

Comparative Polymerization Examples 1 to 6 (Preparation of Hydrocarbon Resins G to L) The same operation as in Polymerization Example 1 was carried out using benzene as a solvent and a monomer mixture shown in Table 2 to obtain hydrocarbon resins G to L. L
I got

[0035]

[Table 2]

The resins obtained in Polymerization Examples 1 to 3 in Table 1 and the resins obtained in Comparative Polymerization Examples 1 to 3 in Table 2 are resins having almost the same softening point. However, the resins obtained in Polymerization Examples 1 to 3 using a hydrocarbon mixed solvent containing a cyclomonoolefin had a softening point of Comparative Polymerization Examples 1 to 3 using a benzene solvent, which was lower in weight than the corresponding resin. It is clear that the molecular weight is smaller. Similar results were obtained when styrene was copolymerized (Table 1, Polymerization Examples 4 to 6 and Table 2, Comparative Polymerization Examples 4 to
6).

Examples 1-4 and Comparative Examples 1-4 (Evaluation as a conjugated diene rubber-based pressure-sensitive adhesive) Polymerization Examples 1-3 and Polymerization Example 5 and Comparative Polymerization Examples 1
The following pressure-sensitive adhesives were prepared using the resins obtained in Comparative Example 3 and Comparative Polymerization Example 5, and the pressure-sensitive adhesive properties were measured. 100 parts of natural rubber (pale crepe, Mooney viscosity 60), 100 parts of the hydrocarbon resin A to C, E, GI or K and 1 part of an antioxidant are dissolved and mixed in toluene, and an adhesive solution having a nonvolatile content of 17% is prepared. Was prepared. Next, this solution was applied on a 25 μm-thick polyester film so as to have a paste thickness of 25 μm to prepare an adhesive tape, and its initial adhesive strength, adhesive strength, and holding power were measured according to the following methods. Table 3 shows the results.

[0038]

[Table 3]

(1) Initial adhesive strength: JIS Z-0237
At 23 ° C, a 10 cm long adhesive surface is stuck on a slope on a stainless steel plate with a slope angle of 30 degrees at 23 ° C, and steel balls of 30 sizes from 3/32 inch to 1 inch in diameter are sloped. The size of the sphere having the largest diameter that stops at 10 cm from the position 10 cm above and stops on the adhesive tape (unit: ball number [= × 1/32 inch]).

(2) Adhesive strength: According to JIS Z-0237, an adhesive tape having a width of 10 mm and a length of 100 mm was adhered to a stainless steel plate polished with a water-resistant abrasive paper of No. 280 at a speed of 200 mm / min at 23 ° C. , And the peeling force (unit: N / m) was measured. (3) Holding force: 10 mm × 10 mm on a stainless steel plate polished with No. 280 water-resistant abrasive paper according to JIS Z-0237.
paste the adhesive tape so that the area of
The time (unit: minute) required for the pressure-sensitive adhesive tape to fall off the stainless steel plate by applying a load of 1 kg at ℃ was measured.

Examples 5 to 8 and Comparative Examples 5 to 8 (Evaluation as a styrene-isoprene-based block copolymer-based pressure-sensitive adhesive) Polymerization Examples 1 to 3, Polymerization Example 5, and Comparative Polymerization Examples 1 to
Using the resins obtained in Comparative Example 3 and Comparative Polymerization Example 5, a pressure-sensitive adhesive was prepared by the following operation, and pressure-sensitive adhesive properties were measured. Styrene-isoprene block copolymer (Quintac 34
21, 100 parts of Zeon Corporation), 100 parts of the hydrocarbon resins A to C, E and G to I, K, 20 parts of naphthenic process oil (Shellflex 371N, manufactured by Shell Chemical Company), antioxidant One part of the agent was dissolved and mixed in toluene to prepare an adhesive solution having a nonvolatile content of 40%. Next, this solution was applied on a 25 μm-thick polyester film so as to have a glue thickness of 25 μm to prepare an adhesive tape,
The initial adhesive strength, adhesive strength and holding power were measured. Except that the measurement of the holding force was performed at 50 ° C., the measuring method and the unit of each physical property were the same as described above. Table 4 shows the results.

[0042]

[Table 4]

Examples 9 to 12 and Comparative Examples 9 to 12 (Evaluation as Hot Melt Adhesive Based on Ethylene-Vinyl Acetate Copolymer) Polymerization Examples 4 to 6, Polymerization Example 2, and Comparative Polymerization Examples 4 to 6
Using the resin obtained in Comparative Polymerization Example 2, an adhesive was prepared by the operation described below, and the adhesive properties were measured. Ethylene-
Vinyl acetate (EVA) copolymer (vinyl acetate content 28
%, Melt index 150g / 10min)
Part, microcrystalline wax (melting point 173 ° F)
50 parts, and the hydrocarbon resins B, D to F, H, J
~ L to make a mixture of 100 parts, JIS K-
The cloud point of each formulation was measured according to the method specified in 2266.

The composition melted at 180 ° C.
After applying 0.2 mm thickness to an aluminum plate having a thickness of 0.2 mm, another aluminum plate is superimposed and a pressure of 1.0 kg / c is applied.
Sealing and fusion were performed for 2 seconds under conditions of m ² and a temperature of 140 ° C. to produce a laminated sample. This sample is cut into 25 mm-width pieces to form test pieces, and the test pieces are pulled at 5 ° C., 20 ° C., and 35 ° C. at a speed of 200 mm / min, and adhered by a 90 ° peeling method (unit: g / inch). ) Was measured. Table 5 shows the results.

[0045]

[Table 5]

[0046]

According to the present invention, cycloolefin alone is used as a polymerization solvent,
Alternatively, the adhesive composition of the present invention containing a specific hydrocarbon resin tackifier prepared using a hydrocarbon mixed solvent containing cycloolefin exhibits excellent adhesive properties. More specifically, the pressure-sensitive adhesive composition has excellent initial adhesive strength and good adhesive strength and holding power, and also has good heat resistance as a hot-melt adhesive composition. Good adhesion over a wide temperature range.

(Preferred Embodiment of the Invention) (a) At least one base polymer selected from an elastomer and a thermoplastic resin, and (b) a monoolefin and a chain having 4 to 5 carbon atoms as a tackifier. An adhesive composition comprising a hydrocarbon resin having a softening point of 60 to 130 ° C. obtained by cationically polymerizing a conjugated diene with an acidic metal halide catalyst, wherein cycloolefin is used as a polymerization solvent. Preferred embodiments of the adhesive composition of the present invention, wherein the above polymerization is carried out using a hydrocarbon mixed solvent containing 5% by weight or more of a cycloolefin, are as follows.

1. The cycloolefin is cyclohexene or cyclopentene. 2. The hydrocarbon mixed with the cycloolefin is an aliphatic hydrocarbon. 3. The chain conjugated diene having 4 to 5 carbon atoms is at least one selected from 1,3-pentadiene, isoprene and butadiene. 4. The monoolefin to be copolymerized with the chain conjugated diene having 4 to 5 carbon atoms is at least one selected from monoolefinically unsaturated hydrocarbons having 4 to 10 carbon atoms.

5. Monoolefin to be copolymerized with a chain conjugated diene having 4 to 5 carbon atoms is selected from butenes, pentenes, methylbutenes, methylpentenes, diisobutylene, cyclopentene, cyclohexene, methylcyclopentenes, styrene and methylstyrenes At least one kind. 6. The ratio between the monoolefin and the conjugated diene having 4 to 5 carbon atoms is 94/6 to 15/85 (weight ratio). 7. The acidic metal halide catalyst is an aluminum, boron or iron fluoride, chloride, bromide or iodide, more preferably an aluminum halide.

8. Prior to polymerization, the acidic metal halide catalyst is contacted with a monocyclic monoolefin at least 5 times (by weight) the catalyst. 9. In the above item 8, the monocyclic monoolefin contacted with the acidic metal halide catalyst is a cyclic monoolefin having 5 to 6 carbon atoms, more preferably cyclopentene or cyclohexene. 10. The softening point of the hydrocarbon resin produced by polymerization is 70
~ 120 ° C.

11. The adhesive composition has a tackifier composed of a hydrocarbon resin in an amount of 5 to 300 parts by weight, more preferably 100 parts by weight of at least one base polymer selected from an elastomer and a thermoplastic resin. 40
-200 parts by weight. 12. The adhesive composition is a pressure-sensitive adhesive containing, as a base polymer, a conjugated diene rubber or a thermoplastic elastomer composed of an aromatic monoolefin polymer block and a conjugated diolefin polymer block.

13. The conjugated diene rubber of the above 12 is a natural rubber, a styrene-butadiene copolymer rubber (SB
R), selected from synthetic polyisoprene rubber and polybutadiene rubber, more preferably natural rubber or SB
R and usually has a Mooney viscosity of 20 to 100, more preferably 30 to 80. 14． The above 13 SBR has a bound styrene content of 15 to 5
It is a random copolymer having 5% by weight, more preferably 20 to 50% by weight, a number average molecular weight of 100,000 to 1,000,000, and more preferably 200,000 to 500,000.

15. The thermoplastic elastomer comprising the aromatic monoolefin polymer block and the conjugated diolefin polymer block of the above 12 is a compound represented by the general formula (AB) _n or (AB) _n-1 A (where A is substantially , An aromatic monoolefin polymer block, B is a substantially conjugated diolefin polymer block, and n represents an integer of 2 to 10.)
10 to 70% by weight, more preferably 10 to 55% by weight of an aromatic monoolefin polymer block content represented by
And a block copolymer having an average molecular weight of 25,000 to 500,000, more preferably 40,000 to 200,000.

16. The adhesive composition is a hot melt adhesive containing, as a base polymer, a thermoplastic resin; or a thermoplastic elastomer selected from styrene-butadiene-based block copolymers and styrene-isoprene-based block copolymers. is there. 17． The above-mentioned thermoplastic polymer is an ethylene polymer.

18. The ethylene polymer of the above 17 is a homopolymer of ethylene, or ethylene and an unsaturated selected from vinyl acetate, vinyl propionate, ethyl acrylate, butyl acrylate, methyl methacrylate, and ethyl methacrylate. It is a copolymer with an ester and a monomer selected from the group consisting of unsaturated acids selected from acrylic acid and methacrylic acid. 19. The adhesive composition is a hot melt adhesive containing, as a base polymer, an ethylene-unsaturated ester copolymer having an unsaturated ester content of 10 to 50% by weight and a melt index of 0.5 to 2,500.

Claims (1)

[Claims] (1) at least one base polymer selected from an elastomer and a thermoplastic resin,
(B) Monoolefin and carbon number 4 or more as tackifiers
Softening point of 60 to 1 obtained by cationic polymerization of the chain conjugated diene of No. 5 with an acidic metal halide catalyst.
A pressure-sensitive adhesive composition comprising a hydrocarbon resin at 30 ° C., wherein the polymerization is performed using a cycloolefin or a hydrocarbon mixed solvent containing 5% by weight or more of a cycloolefin as a polymerization solvent. Adhesive composition.