JPS614711A - Low-softening point hydrocarbon polymer and its use - Google Patents

Abstract

PURPOSE:A low-softening point hydrocarbon polymer useful as an additive for a pressure-sensitive adhesive having a specified composition of an unsaturated hydrocarbon and 9,10-dihydrodicyclopentadiene or its derivative and a specified softening range. CONSTITUTION:The titled low-softening point hydrocarbon polymer of a softening point <=about 60 deg.C is obtained by copolymerizing (A) an unsaturated hydrocarbon (preferably 4-6C linear diolefin, 8-10C aromatic alkenyl compound, or 8-10C 1,2-dimethylidene compound) with (B) 9,10-dihydrodicyclopentadiene or its derivative at such a ratio that polymer units (A) amount to about 20-98 mol% and polymer units (B) amount to about 80-2mol% (the total of the both being 100mol%). The obtained polymer is useful as an additive for a pressure- sensitive adhesive, especially, as a tackifier for a hot-melt or solvent-type pressure-sensitive adhesive.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to low softening point hydrocarbon polymers.

More specifically, the present invention relates to a low softening point hydrocarbon polymer useful as a tackifier or softener for pressure sensitive adhesives, particularly hot melt pressure sensitive adhesives or solvent type pressure sensitive adhesives.

[Problems to be solved by conventional technology/invention]

In recent years, in addition to conventional pressure-sensitive adhesives such as solvent-based and emulsion-based adhesives, hot-melt adhesives have come into widespread use. The main uses of hot-melt pressure-sensitive adhesives include labels, craft tapes, and cloth tapes. Among these, tapes that are frequently used in the packaging field, especially for corrugated poles, require a well-balanced adhesive performance such as corrugated pole adhesion at low temperatures, tack, adhesion, cohesive force, and corrugated board holding power. Ru.

These performances are highly dependent on the elastomer, which is the main component of hot-melt pressure-sensitive adhesives, and especially on the tackifier (tackifier). There wasn't.

[Means to try to solve problems]

By the way, recently, hydrocarbon resins have been increasingly used as cookers for hot-melt pressure-sensitive adhesives, replacing conventionally used resins such as rosin resins and terpene resins. As such, the present applicant previously proposed a hydrocarbon resin having specific compositional properties (Japanese Patent Application Laid-open No. 58-42610>.

As a result of further studies on the resin, the present inventors found that a resin having a specific composition and softening point range is surprisingly effective in solving the above problems, and furthermore, a hot melt pressure sensitive adhesive. The present inventors have discovered that it is also excellent as a softener for solvent-based pressure-sensitive adhesives, and have completed the present invention.

That is, the present invention is characterized by the unsaturated hydrocarbon (A) and 9.10
-dihydrodicyclopentadiene or its derivative (B
), wherein the polymerized units of (A) are about 20 to 98 mol% and the polymerized units of (B) are about 80 to 2 mol% [the total of both is 100 mol%] The present invention relates to a hydrocarbon polymer that is copolymerized at a ratio within the range of and has a softening point of about 60°C or less, and furthermore, an additive for pressure-sensitive adhesives made of the polymer is defined as a usage invention.

[(A) component]

Specifically, the unsaturated hydrocarbon (A) forming the hydrocarbon polymer according to the present invention is, for example, ethylene, propylene,
1-butene, 2-butene, isobutylene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-
Chain monoolefins such as heptene and 2-octene, 1
．． 3-butadiene, isoprene, 2,3-dimethyl-1
, 3-butadiene, 1,3-pentadiene, 2.3-dimethyl-1,3-hexadiene, 1.4-pentadiene, 3,4.5-) dimethyl-1,6-hebutadiene, etc.; 1.2-dimethylidenecyclohexane, 1.2-dimethylidenecyclopenkune, vinylcyclohexane, limonene, styrene, vinyltoluene, α-methylstyrene, isopropenyltoluene, tertiary
Examples include cyclic hydrocarbons having unsaturated bonds in side chains, such as butylstyrene, allylbenzene, and p-tert-butylallylbenzene.

Among the hydrocarbons listed above, particularly preferred from the viewpoint of resin performance are chain diolefins having 4 to 6 carbon atoms, aromatic alkenyl compounds having 8 to 10 carbon atoms, and carbon atoms having 8 to 10 carbon atoms. Examples include 1,2-dimethylidene compounds.

These hydrocarbons can be used singly or in mixtures of two or more homologous compounds, as well as monoolefins and diolefins, monoolefins and cyclic hydrocarbons having unsaturated bonds in their side chains, and diolefins and cyclic hydrocarbons having unsaturated bonds in their side chains. It is used as a cyclic hydrocarbon having an unsaturated tertiary bond, or a mixture of a monoolefin, a diolefin, and a cyclic hydrocarbon having an unsaturated bond on the side l.

[(B) component]

9,10-dihydrodicyclopencdiene or its derivative (B) to be copolymerized with these hydrocarbons is a compound represented by the following general formula; R2 is a hydrogen atom, a halogen atom, a methyl group, or a methoxy group, and R1 located at the 3- to 10-positions is a hydrogen atom, a halogen atom, a hydroxyl group, -R3, -0R4, -R,OR,, -R Wow, -G
OOR8, -COR,, -0POR,.

(However, R3, R4, Ro, R9, and R9 have 1 to 1 carbon atoms.
10 alkyl group, an aryl group having 6 to 10 carbon atoms, or an aralkyl group, and RE and R7 each have 1 to 1 carbon atoms.
0 alkylene group, RIO represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group or an aralkyl group having 6 to 10 carbon atoms), an isocyanate group or an aldehyde group], specifically, For example, 9-methyl-9,10-dihydrodicyclopencdiene, 3.9-
dimethyl-9,10-dihydrodicyclopentadiene,
9-hydroxy-9,10-dihydrodicyclopentadiene, 9-methoxy-9,10-dihydrodicyclopentadiene, 9-acetyl-9,10-dihydrodicyclopentadiene, 9-phenoxy-9,10-dihydrodicyclo Pentadiene, 9-isocyanato-9,10-
Dihydrodicyclopentadiene, bishydrogen phosphate (9,
10-dihydrodicyclopencdiene) and the like.

These 9,10-dihydrodicyclopentadienes can be obtained, for example, as follows. First, 9.10-dihydrodicyclopentadiene is obtained by heat-treating cyclopentadiene in the C6 fraction produced by naphtha decomposition etc. to form dicyclopentadiene, and then hydrogenating the double bond of the norbornene ring. It is obtained by Hydrogenation is
A known method, for example, using one or more of nickel, palladium, cobalt, platinum, ruthenium, rhodium, copper, etc., or oxides of these metals as a hydrogenation catalyst, at room temperature or under elevated pressure. Alternatively, it is carried out by adding hydrogen gas at a predetermined molar ratio under pressure. In addition, 9,10-dihydrodicyclopentadiene derivatives can be obtained by thermally dimerizing cyclopenc diene derivatives,
It is synthesized by partially hydrogenating this. Furthermore,
Derivatives of 9,10-dihydrodicyclopentadiene can also be synthesized by adding alcohols, carboxylic acids, isocyanic acid, phosphoric acid, etc. to dicyclopentadiene or its derivatives in the presence of an acid catalyst. .

It goes without saying that the 9,10-dihydrodicyclopentadiene used should be substantially pure, but if it has a purity of about 60% by weight or more in these polymerization components, this In addition, it may contain polymerizable components such as cyclopentene, partially hydrogenated cyclopentadiene oligomer (trimer or higher), isoprene-cyclobenk diene codimer or partially hydrogenated oligomer, and non-polymerizable components. It may contain tetrahydrodicyclopentadiene or its derivatives.

However, cyclopentadiene,
Dicyclopentadiene, trimer or higher cyclopentadiene oligomers, and their derivatives, etc., account for 10% of this polymerization component.
It is desirable to use less than i amount%.

[Polymerization method]

When copolymerizing hydrocarbons and 9,10-dihydrodicyclopentadiene, 9,10-dihydrodicyclopentadiene generally has low reactivity, so a large amount of 9,10-dihydrodicyclopentadiene is used, and it is brought into contact with a catalyst in advance. Then, by blowing or adding a small amount of hydrocarbons, it is possible to increase the reactivity of 9,10-dihydrodicyclopentadiene and increase the proportion of its polymerized units. desirable.

9. Chain diolefins, especially chain conjugated diolefins, 1,3-butadiene with less neutral hindrance as unsaturated hydrocarbons because of their high copolymerizability with 10-dihydrodicyclopentadiene, Preference is given to using isoprene, 1,3-pentadiene, 2,3-dimethyl-butadiene.

As the copolymerization catalyst, those known as homopolymerization and copolymerization catalysts for the above-mentioned hydrocarbons can be used as they are. That is, cationic catalysts, anionic catalysts, iodicoordination catalysts, radical catalysts, etc. are used. Among these, cationic catalysts are preferred.

Examples of the cationic polymerization catalyst include the cationic polymerization catalyst described in the Japan Petroleum Institute, Vol. 16, No. 10, pp. 865-867 (1973), specifically AlCl3, AlBr3, B
F3, BF, phenol, 5nC14, 5bC1,
F'eC1, AIRCl (R: alkyl group), 8 IE
t, -H,0, CGI C00HXH0so, etc. Among these, the absorption rate of hydrocarbon resin is high;
In terms of good hue, AlCl3, AlBr3, BF3,
Lewis acids, especially Br3, BF3, phenol, etc., are excellent in that they are easy to obtain products with low softening points such as BF3/phenol. These polymerization catalysts reduce the catalytic activity when the 9.10-dihydrodicyclopencdienes contain a hydroxyl group or carbonyl group, but when they do not contain these groups, the catalytic activity decreases. It can be used without any trouble.

The amount of each of the above polymerization catalysts used varies depending on the type of catalyst, combination of comonomers, polymerization temperature, polymerization time, etc.
Generally from about 0.01 to 10 mole percent based on monomer.

Polymerization solvents may or may not be used, but for all catalyst systems propane, furan, benzene, hexane, benzene, henzene, toluene, xylene,
It is possible to use hydrocarbon solvents such as ethyl hesozene. In addition, anionic polymerization catalysts include ethers such as diethyl ether, tetrahydrofuran, dioxane, and 1,2-dimethoxyethane, and cationic polymerization catalysts include chlorine compounds such as dichloromethane, ethyl chloride, 1,2-dichloroethane, and chlorhenzene. In the case of a radical polymerization catalyst, water can be used as a compound solvent, and if emulsion or suspension polymerization is employed, water can be used.

The polymerization temperature can be selected from a range of -10°C to about 150°C, and the polymerization time is about 1/2 to 10 hours. As for the pressure, normal pressure or pressurized conditions are generally used. After the copolymerization reaction is completed, the remaining catalyst is treated according to a conventional method, and the unreacted components and reaction solvent are removed by distillation or addition to a poor solvent for the hydrocarbon polymer, and the desired hydrocarbon polymer is produced. can be obtained.

The ratio of polymerized units of (A) and (B) constituting the hydrocarbon polymer can be controlled by the ratio of the amounts of (A) and (B) used.

In addition, the softening point can be controlled by controlling the polymerization temperature, monomer concentration,
This can be easily done depending on the catalyst concentration.

For example, increasing the polymerization temperature, decreasing the monomer concentration, and increasing the catalyst concentration generally lowers the softening point.

As an alternative method for obtaining a low softening point hydrocarbon polymer, when producing a high softening point hydrocarbon polymer having a similar resin composition,
The low softening point hydrocarbon polymer partially contained in the fraction removed as the solvent and unreacted residue can also be obtained by further separating it by distillation or the like.

[Properties of polymer]

The hydrocarbon polymer obtained as described above contains about 20 to 98 mol% of polymerized units of hydrocarbons consisting of unsaturated hydrocarbons,
Preferably about 40 to 98 mol%, particularly preferably about 45
~95 mol%, and the polymerized units of 9,10-dihydrodicyclopentadiene consisting of 9,10-dihydrodicyclopentadiene or its derivatives are about 80 to 2 mol%, preferably about 60 to 2 mol%, Particularly preferably about 55 to 5 mol%, with a softening point (JIS K-25
liquid according to the ring and ball method according to 31), preferably about 50 c
ps or less, particularly preferably about 20 to 1 cps (Emiller viscometer, polymer temperature 200° C.) and preferably about 200 to 500, particularly preferably about 250
It has a molecular weight (GPC method (polystyrene conversion method: number average molecular weight)) of ~450.

9. When the polymerized unit of 10-dihydrodicyclopenc diene is 2 mol% or less, the molecular weight of the resulting hydrocarbon polymer increases, and sufficient plasticizing effect and adhesive performance (corrugated board adhesion, tack, adhesive strength) are obtained. ), and if the polymerized unit is 80 mol% or more, homopolymerizability will be poor due to the structure of 9,10-dihydrodicyclopentadiene, so for example, do not make the catalyst concentration abnormally high. This not only increases the difficulty in manufacturing, but also causes problems such as poor quality, poor hue, and poor thermal stability. It is necessary to be within. Furthermore, if the softening point of the hydrocarbon polymer of the present invention exceeds 60°C, adhesive properties such as cardboard adhesion and tack at low temperatures will be poor, so it is necessary that the softening point be within this range.

[Use invention]

Next, additives for pressure-sensitive adhesives made of the polymer according to the present invention, particularly additives as tackifiers or softeners for hot-melt pressure-sensitive adhesives or solvent-type pressure-sensitive adhesives, will be explained.

[Hot melt pressure sensitive adhesive]

Hot-melt pressure-sensitive adhesives usually consist of a base resin, a Tackifier-1 softener, and other additives. The polymer of the present invention is extremely useful both as a tackifier and as a softener in this case.
When applied to adhesive tapes for packaging, it is possible to obtain adhesive tapes with well-balanced adhesive properties such as cardboard adhesion, tack, adhesion, cohesive strength, and cardboard retention strength. Furthermore, the polymer of the present invention also has excellent compatibility with the base resin.

When the hydrocarbon polymer according to the present invention is added as a tackifier to a hot-melt pressure-sensitive adhesive, specific examples of the base resin include styrene-butadiene copolymer, polybutadiene, polyisobutylene, butyl rubber, etc. , ethylene/propylene copolymer rubber, ethylene/
Propylene/diene copolymer rubber, styrene/butadiene/styrene block copolymer, styrene/isoprene/
Rubbery polymers such as styrene block copolymers are used.

When the polymer of the present invention is used as a tackifier for hot-melt pressure-sensitive adhesives, the blending ratio is usually 5 to 20 parts by weight per 100 parts by weight of the base resin, although it depends on other conditions.
0 parts by weight, preferably in the range of 10 to 150 parts by weight, and when used as a softener, usually 5 to 1 parts by weight.
00 parts by weight, preferably in the range of 10 to 50 parts by weight.

In addition, when the polymer of the present invention is added as a tackifier or softener for a hot-melt pressure-sensitive adhesive,
Other softeners or tackifiers may also be used. In this case, the softening agent is dioctyl phthalate,
Dibutyl phthalate, machine oil, process oil, polybutene, etc. can be used. Other tackifiers that can be used include rosin and derivatives thereof, terpene resins, alicyclic resins, aliphatic resins, aromatic resins, and aliphatic-aromatic copolymer resins. Examples of other additives include fillers such as calcium carbonate, zinc white, titanium oxide, and silica, anti-aging agents such as amine-based, ketone-amine-based, and phenol-based antioxidants, and stabilizers. The blending ratio of these additives is arbitrary and appropriate.

To prepare a hot-melt pressure-sensitive adhesive composition, the base resin and, if necessary, other tackifiers 1.
A mixture of the polymer of the present invention together with a softener and additives may be heated and stirred to form a uniform melt. A pressure-sensitive adhesive tape can be obtained by applying the melt onto cloth, kraft paper, synthetic film, etc. using a hot-melt coating machine.

[Solvent-based pressure-sensitive adhesive]

Next, the use of the polymer of the present invention as a softener for a solvent-type pressure-sensitive adhesive will be explained. Specific examples of the base resin in this case include natural rubber, styrene-butadiene copolymer rubber, polybutashene, polyisoprene, polyisobutylene, butyl rubber, polychloroprene,
Rubber-like polymers such as ethylene/propylene copolymer rubber, ethylene/propylene/diene copolymer rubber, styrene/butadiene/styrene block copolymer, and styrene/isoprene/styrene block copolymer are used.

The proportion of the polymer of the present invention to be used depends on various conditions, but is usually in the range of 5 to 100 parts by weight, preferably 10 to 50 parts by weight, per 100 parts by weight of the base resin.

In addition, other softeners such as dioctyl phthalate, dibutyl phthalate, machine oil, process oil, polybutene, etc. may be used together with the polymer of the present invention, and other additives such as calcium carbonate, zinc white,
Fillers selected from titanium oxide, silica, etc.; anti-aging agents such as amine-based, ketone-amine-based, and phenol-based;
Stabilizers are added. The blending ratio of these additives is arbitrary and appropriate.

A method for preparing a solvent-type pressure-sensitive adhesive using the polymer of the present invention as a softener includes the polymer of the present invention as a tackifier and softener, the base resin, and the above-mentioned various types as necessary. It can be prepared by conventional methods such as dissolving a mixture of additives in a suitable solvent.

[Examples] [Effects of the Invention] Reference Example 1 A C5 fraction obtained by naphtha decomposition was heated at 150° C. for 3 hours, and the cyclopentadiene contained therein was converted to dicyclopentadiene. Next, the light fraction was removed by distillation, resulting in a C5 fraction of 4.8% and 0.5%.
5%, dicyclopentadiene 77.1%, isoprene-cyclopentadiene codimer 7.2%, cyclopentadiene oligomer 8.2% and unknown component 2.2%. .

In a metal autoclave, 100 parts by weight (1710 g) of this crude dicyclopentadiene and a palladium-based hydrogenation catalyst in the form of tablets (Toyo C.C.I. product C3) were placed in a metal autoclave.
l-IA) 4 parts by weight are charged and the hydrogenation reaction is carried out under the conditions of a reaction temperature of 50°C and a hydrogen pressure of 10 kg/crA with stirring for 12 hours. child. The catalyst was removed by filtration, and the mixture was distilled to obtain 90 parts by weight of a 9.10-disidolodicyclobentadiene fraction. Gas chromatography analysis results showed 19.0% of penkune, 77.0% of 9,10-dihydrodicyclopentadiene, less than 0.1% of dicyclopentadiene, 0.8% of tetrahydrodicyclopentadiene, and unknown components. It showed a composition of 3.2%.

Reference Example 2.3 A predetermined amount of catalyst and a portion of the solvent (20 ml) were charged in a glass autoclave with a capacity of 1β, and while stirring, a predetermined amount of 9,10-dihydrodicyclopentadiene obtained in the above reference example was added. The fraction, the 1,3-pencudiene-containing fraction shown in Table 1, and the remainder of the solvent were slowly injected as a mixture from a pressure cylinder. At this time, heating or cooling was performed to maintain the temperature at 60° C., and each monomer was injected for about 15 minutes.

Furthermore, after continuing the polymerization reaction at this temperature for about 2 hours, methanol was added to separate the catalyst, and the catalyst was washed with water. After passing the polymerized oil through a glass filter and checking for the presence or absence of gel formation, the oral liquid was concentrated to obtain a hydrocarbon resin. The properties of the obtained hydrocarbon resin are shown in Table 2 below.

Examples 1 to 4 A predetermined amount of catalyst and a portion (20 ml) of a solvent were charged into a glass autoclave having a capacity of 11, and while stirring, a predetermined amount of the 9,10-dihydrodicyclopentadiene-containing distillate obtained in the reference example was added. and various unsaturated hydrocarbons, as well as the remainder of the solvent, are slowly injected as a mixture from a pressure cylinder. At this time, heating or cooling was performed to maintain a predetermined temperature, and each monomer was injected for about 15 minutes. Furthermore, after continuing the polymerization reaction at this temperature for about 2 hours, methanol was added to decompose the catalyst, and the catalyst was washed with water. The polymerized oil was passed through a glass filter, and the oral liquid was concentrated to obtain a hydrocarbon resin. The properties of the obtained hydrocarbon resin are shown in Table 4 below.

Example 5 Polymerization was carried out in the same manner as in Example 1 except that the C9 fraction shown in Table 3 was used as the unsaturated hydrocarbon to obtain the hydrocarbon resin shown in Table 4.

Example 6 A hydrocarbon resin shown in Table 4 was obtained in the same manner as in Example 1 except that α-methylstyrene was used as the unsaturated hydrocarbon.

Comparative Examples 1 to 4 In the same manner as in Example 1, 9.10-': homopolymerization of a hydrodicyclopentadiene-containing fraction, homopolymerization of a 1,3-pentadiene-containing fraction, and homopolymerization of a 9,10-dihydrodicyclopentadiene-containing fraction. Copolymerization of fractions containing 1,3-penc diene and butadiene and homopolymerization of butadiene were carried out. The properties of the obtained hydrocarbon resin are shown in Table 5 below.

Examples 7-12. Comparative Examples 5-6 SIS block copolymer (Shell Chemical Co., Ltd. r TR-1
107J) 100 parts by weight, softener (Shell Chemical Co., Ltd. "Shell Flex 22RJ") 30 parts by weight, stabilizer (
3 parts by weight of "Ircalix 1010" manufactured by Geigy,
30 parts by weight of the resins obtained in Examples 1 to 6 or Comparative Examples 2 to 3 were blended with 70 parts by weight of the resin obtained in Reference Example 2 as a glue fire, and the mixture was kneaded at 150°C for 30 minutes in a niegu machine to form an adhesive. It was adjusted. This adhesive was melted and applied to a thickness of 50±5 μm using an applicator on a polyester film (25 μm thick) on a hot plate at 195° C. for 20 minutes to make 8 wraps of the adhesive tape.

Next, adhesive performance was evaluated using the test method shown below.

(1) Made of corrugated pole adhesive = Adhesive tape is pressed onto corrugated pole paper (JIS L7) at a temperature of 5°C by rolling an 850 g rubber roller, immediately peeled off, and the surface condition of the corrugated pole paper is examined.

Rating 5: The entire surface of the corrugated paper is destroyed.

4: 30% or more of the surface of the corrugated paperboard is destroyed.

3: Destruction of the surface of the corrugated paperboard is clearly observed.

2: Slight damage to the surface of the corrugated paper was observed.

1: No surface destruction of cardboard was observed.

(2) Tuck (Ball No.): J,
It was measured at 20''C by the Dow method.

(3) Adhesive strength (g/25mm): JIS
It was measured at 20°C by the method of Z-1524.

(4) Cohesive force (mm/2) [R]: JIS Z
-1524 method at 20°C.

(5) Corrugated board retention force (HR): Corrugated paper (JIS K-7) was used as an adherend, a load of 2 kg was suspended at the end, and the time until the load slipped off was measured at 20°C.

Table 6 shows the results obtained by the above test method.

Comparative Example 7 Instead of using the polymer of the present invention, commercially available liquid resin A (
The same procedure as in Example 7 was conducted except that rYs resin PX-200J manufactured by Anza Yushi Co., Ltd. was used.

Comparative Example 8 Using the polymer of the present invention, commercially available liquid resin B was used instead.
(The same procedure as in Example 7 was carried out except that "Dymaron" manufactured by Anza Yushi Co., Ltd. was used.

As a result, when the low softening black carbon and hydrogen chloride polymer obtained according to the present invention are used as a tackifier for hot-metal and melt-type pressure-sensitive adhesives, the resulting adhesive composition is an excellent adhesive compared to the comparative example. It can be seen that the balance of adhesive performance, which had been a problem until now, has been greatly improved.

Examples 13-14. Comparative Example 9 SIS block copolymer (Shell Chemical Co., Ltd. rTR-
1107J)' 100 parts by weight, 80 parts by weight of the resin obtained in Reference Example 3 as a tackifier, 3 parts by weight of stabilizer (Irganox 10IOJ manufactured by Geigy), Example 1, Example 4, and Comparative as a softener. A pressure-sensitive adhesive was prepared in the same manner as in Example 7 by blending 30 parts by weight of the resin obtained in Example 2, and the performance of the pressure-sensitive adhesive was evaluated.

Comparative Example 10 Instead of using the polymer of the present invention, softener A (Shell Chemical Co., Ltd. "Shell Flex 22R") was used, and Example 13
An adhesive was prepared in the same manner as above, and the adhesive performance was evaluated.

Comparative Example 11 Instead of using the resin of the present invention, a softener B (Shell Chemical Co., Ltd. "Shell Flex 371NJ" was used, Example 1
An adhesive was prepared in the same manner as in Example 3, and the performance of the adhesive was evaluated.

Table 7 shows the results of Examples 13 to 14 and Comparative Examples 9 to 11.
Shown below. As a result, all the adhesives obtained by using the polymer of the present invention showed excellent adhesive performance compared to the comparative examples, and the low softening point hydrocarbon polymer of the present invention was found to be suitable for use in hot-melt pressure-sensitive adhesives. It can be seen that it also exhibits excellent performance as a softener.

Examples 15-16. Comparative Example 12 Natural rubber (R5SJ, Mooney viscosity ML (+4 (10
A solvent-type pressure-sensitive adhesive was prepared by mixing 76,130 g of 0'C) obtained in Reference Example 3 as a tackifier and 250 g of toluene. Each of these adhesives was applied onto a polyester film using an applicator and dried at 80° C. for 20 minutes to prepare an adhesive tape. The thickness of the adhesive in the adhesive tape was 20±5μ. Thereafter, the adhesive performance of these adhesive tapes was evaluated using the same test method as in Example 7.

Comparative Example 13 Instead of using the polymer of the present invention, softener A ("Sansen Oil 450" manufactured by Sun Oil Co., Ltd.) was used, and Example 1
A pressure-sensitive adhesive was prepared in the same manner as in Example 5, and the performance of the pressure-sensitive adhesive was evaluated.

Comparative Example 14 Instead of using the polymer of the present invention, softener B (Shell Flex 371NJ manufactured by Shell Chemical Co., Ltd.) was used,
A pressure-sensitive adhesive was prepared in the same manner as in Example 15, and the performance of the pressure-sensitive adhesive was evaluated.

The results of Examples 15-16 and Comparative Examples 12-14 are shown in Table 8.

As a result, all the adhesives obtained by using the polymer of the present invention as a softener showed excellent adhesive performance compared to the comparative examples, and the low softening point hydrocarbon polymer of the present invention was found to be resistant to solvent-based sensitization. It can be seen that it also shows excellent performance as a softener for pressure adhesives.

Claims (2)

[Claims] (1) A copolymer consisting essentially of an unsaturated hydrocarbon (A) and 9,10-dihydrodicyclopentadiene or a derivative thereof (B), wherein the polymerized units of (A) are about 20 to 98 moles. %, the polymerized unit of (B) is about 80 to 2 mol% [the total of both is 100
mol%] and has a softening point of about 6.
A hydrocarbon polymer that has a temperature below 0°C. (2) A copolymer consisting essentially of an unsaturated hydrocarbon (A) and 9,10-dihydrodicyclopentadiene or a derivative thereof (B), wherein the polymerized units of (A) are about 20 to 98 moles. %, the polymerized unit of (B) is about 80 to 2 mol% [the total of both is 100
mol%] and has a softening point of about 6.
An additive for pressure-sensitive adhesives consisting of a hydrocarbon polymer having a temperature of 0°C or less.