JPH0254844B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an additive for pressure-sensitive adhesives comprising a low softening point hydrocarbon polymer. More specifically, an additive for pressure-sensitive adhesives comprising 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. Regarding. [Problems to be solved by conventional technology/inventions] In recent years, in addition to conventional pressure-sensitive adhesives such as solvent-based and emulsion-based adhesives, hot-melt-based 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 used in the field of packaging for cardboard and other items are required to have a well-balanced adhesive performance such as cardboard adhesion at low temperatures, tack, adhesion, cohesive force, and cardboard retention strength. . These performances are highly dependent on the elastomer, which is the main component of hot-melt pressure-sensitive adhesives, and in particular on the tackifier (tackifier), but until now there has been no satisfactory tackifier with a well-balanced adhesive performance. Ta. [Means for solving the problem] By the way, hydrocarbon resins have recently been used as tackifiers for hot-melt pressure-sensitive adhesives in place of rosin-based resins, terpene-based resins, etc. As such, the present applicant previously proposed a hydrocarbon resin having specific compositional properties (Japanese Patent Laid-Open Publication No. 42610/1983). As a result of further studies on the resin, the inventors of the present invention found that a resin having a specific composition and softening point is surprisingly extremely effective in solving the above-mentioned problems. They discovered that it is also excellent as a softener for solvent-type pressure-sensitive adhesives, leading to the completion of the present invention. That is, the present invention combines unsaturated hydrocarbon A and 9, 10
- A copolymer consisting essentially of dihydrodicyclopentadiene or its derivative B, in which 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 gist of the invention is an additive for pressure-sensitive adhesives comprising a hydrocarbon polymer copolymerized in a proportion within the range of 1 and having a softening point of less than 60°C. [Component A] Unsaturated hydrocarbon A forming the hydrocarbon polymer used as an additive for the pressure-sensitive adhesive of the present invention
Specifically, for example, ethylene, propylene,
1-butene, 2-butene, isobutylene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, 3-methyl-1-pentene, 4-methyl-
Chain monoolefins such as 1-pentene, 1-heptene, 2-octene, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2,3-dimethyl-
1,3-hexadiene, 1,4-pentadiene,
Chain diolefins such as 3,4,5-trimethyl-1,6-heptadiene, 1,2-dimethylidenecyclohexane, 1,2-dimethylidenecyclopentane, vinylcyclohexane, limonene, styrene, vinyltoluene, α-methylstyrene , isopropenyltoluene, tert-butylstyrene, allylbenzene, and p-tert-butylallylbenzene. Among the hydrocarbons listed above, those having 4 to 6 carbon atoms are particularly preferable from the viewpoint of resin performance.
Examples include chain diolefins, aromatic alkenyl compounds having 8 to 10 carbon atoms, and 1,2-dimethylidene compounds having 8 to 10 carbon atoms. These hydrocarbons can be used alone or as a mixture of two or more homologous compounds, as well as monoolefins and diolefins, monoolefins and cyclic hydrocarbons with unsaturated bonds in their side chains, and diolefins and unsaturated bonds in their side chains. cyclic hydrocarbons with bonds,
It is used as a mixture of monoolefin, diolefin, and cyclic hydrocarbon having an unsaturated bond in the side chain. [Component B] 9,10-dihydrodicyclopentadiene or its derivative B copolymerized with these hydrocarbons
is a compound represented by the following general formula, [Here, R ₂ located at the 1- or 2-position is a hydrogen atom, a halogen atom, a methyl group, or a methoxy group, and R ₁ located at the 3- to 10-positions is a hydrogen atom,
Halogen atom, hydroxyl group, -R ₃ , -OR ₄ , -
R ₅ OR ₆ , −R ₇ OH, −COOR ₈ , −COR ₉ ,

[Polymerization method]

When copolymerizing hydrocarbons and 9,10-dihydrodicyclopentadiene, 9,10-
Since the reactivity of dihydrodicyclopentadienes is low, by using a method such as using a large amount of dihydrodicyclopentadiene, contacting it with a catalyst in advance, and then blowing or adding a small amount of hydrocarbons, It is desirable to increase the reactivity of 9,10-dihydrodicyclopentadiene and increase the proportion of its polymerized units. Chain diolefins, especially chain conjugated diolefins, are used as unsaturated hydrocarbons because of their high copolymerizability with 9,10-dihydrodicyclopentadiene.
It is preferable to use 1,3-butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethyl-butadiene, which have less neutral steric hindrance. 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, ionic coordination catalysts, radical catalysts, etc. are used. Among these, cationic catalysts are preferred. For example, cationic polymerization catalysts include
The cationic polymerization catalyst described in Vol. 16, No. 10, pp. 865-867 (1973), specifically AlCl ₃ , AlBr ₃ , BF ₃ ,
_BF3・phenol, _SnCl4 , _SbCl5 , _FeCl3 ,
_AlRCl2 (R: alkyl group), _AlEt3 - _H2O ,
There are CCl ₃ COOH, H ₂ SO, etc. Among these, AlCl ₃ , AlBr ₃ , BF ₃ , BF ₃ and phenol are superior in that they have a high absorption rate for hydrocarbon resins and a good hue, and have a low softening point. Lewis acids, especially BF ₃ and BF ₃ phenol, are excellent in that they are easy to obtain. And these polymerization catalysts are 9, 10
When the -dihydrodicyclopentadiene contains a hydroxyl group or a carbonyl group, the catalytic activity is reduced, but when it does not contain these groups, it can be used without reducing the catalytic activity. 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., but is generally about 0.01 to 10% of the amount of monomer.
It is mole%. Polymerization solvents may or may not be used, but for all catalyst systems propane, butane, pentane, hexane, heptane,
It is possible to use hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene. In addition, anionic polymerization catalysts include diethyl ether, tetrahydrofuran, dioxane, 1,2-
Ethers such as dimethoxyethane are used as cationic polymerization catalysts, chlorinated solvents such as dichloromethane, ethyl chloride, 1,2-dichloroethane, and chlorobenzene are used as radical polymerization catalysts, and emulsion or suspension polymerization methods are used as radical polymerization catalysts. Water is,
Each can be used. The polymerization temperature can be selected from the range of about -10℃ to about 150℃, and the polymerization time can be selected from about 1/2 to 100℃.
A time range is used. 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. Hydrocarbon polymers can be obtained. The ratio of monomer units of A and B constituting the hydrocarbon polymer can be controlled by the ratio of amounts of A and B used. Furthermore, the softening point can be easily controlled by controlling the polymerization temperature, monomer concentration, and catalyst concentration. For example, increasing the polymerization temperature, decreasing the monomer concentration, and increasing the catalyst concentration generally lowers the softening point. Another method for obtaining low softening point hydrocarbon polymers is
When producing a high softening point hydrocarbon polymer having a similar resin composition, the low softening point hydrocarbon polymer partially contained in the fraction that is removed as a solvent and unreacted monomer is further separated by distillation, etc. You can also get it. [Properties of polymer] The hydrocarbon polymer obtained as described above has about 20 to 20 polymerized units of hydrocarbons consisting of unsaturated hydrocarbons.
98 mol%, preferably about 40 to 98 mol%, particularly preferably about 45 to 95 mol%, and polymerization of 9,10-dihydrodicyclopentadiene consisting of 9,10-dihydrodicyclopentadiene or a derivative thereof. about 80 to 2 mol%, preferably about 60 to 2
mol %, particularly preferably about 55 to 5 mol %,
The essential range is less than 60°C, preferably less than about 30°C, which is a liquid with a softening point (ring and ball method according to JIS K-2531), and a melt viscosity of preferably about 50 cps or less, particularly preferably about 20 to 1 cps (emiller viscometer). , polymer temperature of 200° C.) and a molecular weight [GPC method (polystyrene equivalent method: number average molecular weight)] of preferably about 200 to 500, particularly preferably about 250 to 450. When the polymerized unit of 9,10-dihydrodicyclopentadiene is 2 mol% or less, the molecular weight of the resulting pressure-sensitive adhesive additive made of a hydrocarbon polymer increases, and sufficient plasticizing effect and adhesive performance ( If the polymerized units exceed 80 mol%, homopolymerizability will be poor due to the structure of 9,10-dihydrodicyclopentadiene. This not only increases the difficulty in manufacturing, but also causes problems such as poor quality and poor thermal stability. It is necessary that the ratio be within the above-mentioned required range. Furthermore, if the softening point of the hydrocarbon polymer of the present invention exceeds 60°C, adhesive properties such as low-temperature corrugated board adhesion and tack will be poor, so it is necessary that the softening point be within this range. Next, the additive for pressure-sensitive adhesives according to the present invention, particularly the additive as a tackifier or softener for hot-melt type pressure-sensitive adhesives or solvent-type pressure-sensitive adhesives, will be explained. [Hot-melt pressure-sensitive adhesive] A hot-melt pressure-sensitive adhesive is usually composed of a base resin, a tackifier, a softener, and other additives. The additive for pressure-sensitive adhesives of the present invention is extremely useful whether used as a tackifier or a softener in this case, and when applied to adhesive tapes for packaging, it improves corrugated board adhesion, tackiness, and adhesive strength. It is possible to obtain a product with a well-balanced adhesive performance such as cohesive force and cardboard holding power. Furthermore, the additive for pressure-sensitive adhesives of the present invention has excellent compatibility with the base resin. When the additive for pressure-sensitive adhesives according to the present invention is added as a tackifier to a hot-melt pressure-sensitive adhesive, specifically, as the base resin,
For example, styrene-butadiene copolymer, polybutadiene, polyisobutylene, butyl rubber, ethylene-propylene copolymer rubber, ethylene, propylene-diene copolymer rubber, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer. Rubber-like polymers such as In the hot melt type pressure sensitive adhesive of the present invention, the blending ratio of the polymer used as a tackifier is usually 5 to 200 parts by weight, preferably 5 to 200 parts by weight, based on 100 parts by weight of the base resin, although it depends on other conditions.
The amount ranges from 10 to 150 parts by weight, and when used as a softener, it usually ranges from 5 to 100 parts by weight, preferably from 10 to 50 parts by weight. In addition, when the polymer of the present invention is added as a tackifier or softener for the hot melt type pressure-sensitive adhesive, other softeners or tackifiers can also be used together. As the softening agent in this case, 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, a mixture of the polymer of the present invention together with the base resin and, if necessary, other tackifiers, softeners, and additives is stirred while heating and melting. A uniform melt may be used. A pressure-sensitive adhesive tape can be obtained by applying the melt onto cloth, kraft paper, synthetic film, etc. using a hot-melt cloth machine. [Solvent Type Pressure Sensitive Adhesive] Next, a softening agent for a solvent type pressure sensitive adhesive which is an embodiment of the present invention will be described. Specific examples of the base resin in this case include natural rubber, styrene, butadiene copolymer rubber, polybutadiene, polyisoprene, polyisobutylene, butyl rubber, polychloroprene, ethylene-propylene copolymer rubber, and ethylene-propylene-diene copolymer rubber. Rubber-like polymers such as rubber, styrene/butadiene/styrene block copolymer, styrene/isoprene/styrene block copolymer, etc. are used. The proportion of the additive for pressure-sensitive adhesives of the present invention depends on various conditions, but is usually 5 to 100 parts by weight, preferably 10 to 100 parts by weight, per 100 parts by weight of the base resin.
In the range of 50 parts by weight. In addition, other softeners such as dioctyl phthalate, dibutyl phthalate, machine oil, process oil, polybutene, etc. may be used together with the additive for pressure-sensitive adhesives of the present invention, and other additives such as calcium carbonate, zinc, etc. Fillers selected from titanium oxide, titanium oxide, silica, etc., anti-aging agents such as amine-based, ketone-amine-based, and phenol-based, stabilizers, etc. are added. The blending ratio of these additives is arbitrary and appropriate. As a method for preparing a solvent-type pressure sensitive adhesive using the additive for a pressure sensitive adhesive of the present invention as a softener, the additive for a pressure sensitive adhesive according to the present invention as a tackifier and a softener, It can be prepared by a conventional method, such as by dissolving a mixture of the base resin and, if necessary, the various additives mentioned above, in a suitable solvent. [Effects of the Invention] According to the present invention, a hydrocarbon polymer having a specific composition and softening point range has adhesive properties such as corrugated board adhesion, tack adhesive strength, cohesive force, and corrugated board holding power in a well-balanced manner. It has excellent properties and can be preferably applied as an additive for pressure-sensitive adhesives. [Example] Reference Example 1 A _C5 fraction obtained by naphtha decomposition was heated at 150°C for 3 hours to convert the cyclopentadiene contained therein into dicyclopentadiene. Next, by removing the light fraction by distillation, the _C5 fraction 4.8%,
Benzene 0.5%, dicyclopentadiene 77.1%,
Isoprene-cyclopentadiene codimer 7.2
%, crude dicyclopentadiene having a composition consisting of 8.2% cyclopentadiene oligomer and 2.2% unknown components was obtained. 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.C.,
4 parts by weight of Ai Co. product C31-1A) were charged, and a hydrogenation reaction was carried out under the conditions of a reaction temperature of 50° C. and a hydrogen pressure of 10 Kg/cm ² with stirring for 12 hours. The catalyst was removed by filtration and distilled to obtain 90 parts by weight of a 9,10-disidolodicyclopentadiene fraction. Gas chromatography analysis results showed a composition of 19.0% pentanes, 77.0% 9,10-dihydrodicyclopentadiene, less than 0.1% dicyclopentadiene, 0.8% tetrahydrodicyclopentadiene, and 3.2% unknown components. Reference Examples 2 and 3 A predetermined amount of the catalyst and a portion (20 ml) of the solvent were charged into a glass autoclave with a capacity of 1, and while stirring, a predetermined amount of the 9,10-dihydrodicyclopentadiene-containing fraction obtained in the above reference example was added. The 1,3-pentadiene-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. The polymerized oil was filtered through a glass filter, the presence or absence of gel formation was checked, and the filtrate was concentrated to obtain a hydrocarbon resin. The properties of the obtained hydrocarbon resin are shown in Table 2 below.

【table】

[Table] Examples 1 to 4 A predetermined amount of catalyst and a portion (20 ml) of a solvent were charged into a glass autoclave with a capacity of 1, and while stirring, a predetermined amount of 9,10-dihydrodicyclo obtained in the above reference example was added. The pentadiene-containing fraction, various unsaturated hydrocarbons, and 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 filtered through a glass filter, and the filtrate was concentrated to obtain a hydrocarbon resin. The properties of the obtained hydrocarbon resin are as follows:
It is shown in Table 4 below. Example 5 Polymerization was carried out in the same manner as in Example 1 except that the _C5 fraction shown in Table 3 was used as the unsaturated hydrocarbon.
A hydrocarbon resin shown in was obtained.

[Table] 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.

[Table] Comparative Examples 1 to 4 Homopolymerization of a fraction containing 9,10-dihydrodicyclopentadiene, homopolymerization of a fraction containing 1,3-pentadiene, and homopolymerization of a fraction containing 9,10-dihydrodicyclopentadiene in the same manner as in Example 1. Copolymerization of the fraction and a 1,3-pentadiene-containing fraction and homopolymerization of butadiene were carried out. The properties of the obtained hydrocarbon resin are shown in Table 5 below.

【table】

[Table] Examples 7 to 12, Comparative Examples 5 to 6 SIS block copolymer (Ciel Chemical “TR”)
-1107'') 100 parts by weight, 30 parts by weight of a softener (``Ciel Flex 22R'' manufactured by Ciel Chemical Co., Ltd.), 3 parts by weight of a stabilizer (``Irganox 1010'' manufactured by Geigy), 70 parts by weight of the resin obtained in Reference Example 2 Examples 1 to 6
30 parts by weight of the resins obtained in Comparative Examples 2 and 3 were blended as a tackifier and kneaded in a kneader at 150°C for 30 minutes to prepare an adhesive. Apply this adhesive to a polyester film (25μ thick) on a 195℃ heating plate.
An adhesive tape was prepared by melting the adhesive (for 20 minutes) and applying it to a thickness of 50±5μ using an applicator. Next, adhesive performance was evaluated using the test method shown below. (1) Made of cardboard adhesive: Press the adhesive tape onto cardboard paper (JIS K-7) at 5°C by rolling an 850g rubber roller, then immediately peel it off and examine the surface condition of the cardboard paper. Rating 5: The entire surface of the corrugated paperboard is destroyed. 4: 30% or more of the surface of the cardboard is destroyed. 3: Destruction of the surface of the corrugated paperboard was clearly observed. 2: Slight damage to the surface of the cardboard was observed. 1: No surface damage to the corrugated paperboard was observed. (2) Tack (Ball No.): Measured at 20°C by J.Dow method. (3) Adhesive strength (g/25mm width): Measured at 20°C according to JIS Z-1524 method. (4) Cohesive force (mm/2HR): according to JIS Z-1524 method
Measured at 20°C. (5) Corrugated board retention force (HR): Corrugated paper (JIS K-7) was used as the adherend, a load of 2 kg was hung 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 The same procedure as in Example 7 was carried out, except that instead of using the polymer of the present invention, commercially available liquid resin A ("YS Resin PX-200" manufactured by Yasukawa Oil Co., Ltd.) was used. Comparative Example 8 The present invention The same procedure as in Example 7 was carried out except that instead of using the polymer of When the polymer is used as a tackifier for hot-melt pressure-sensitive adhesives, the resulting adhesive composition exhibits superior adhesive performance compared to comparative examples, and the balance of adhesive performance, which had been a problem until now, has been resolved. It can be seen that it has been greatly improved.

[Table] Examples 13 to 14, Comparative Example 9 SIS block copolymer (Ciel Chemical “TR”)
-1107'') 100 parts by weight, 80 parts by weight of the resin obtained in Reference Example 3 as a tackifier, 3 parts by weight of a stabilizer (Irganox 1010 manufactured by Geigy), Example 1, Example 4 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 Comparative Example 2, and the performance of the pressure-sensitive adhesive was evaluated. Comparative Example 10 A softener was used instead of using the polymer of the present invention. Using A (“Ciel Flex 22R” manufactured by Ciel Chemical),
An adhesive was prepared in the same manner as in Example 13, and the performance of the adhesive was evaluated. Comparative Example 11 Instead of using the resin of the present invention, softener B ("Ciel Flex 371N" manufactured by Ciel Chemical Co., Ltd.) was used,
An adhesive was prepared in the same manner as in Example 13, and the performance of the adhesive was evaluated. Table 7 shows the results of Examples 13-14 and Comparative Examples 9-11. 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 a softener for hot melt type pressure-sensitive adhesives. It can be seen that it also shows excellent performance as an agent.

【table】

[Table] Examples 15-16, Comparative Example 12 Natural rubber {RSS# 1, Mooney viscosity ML ₁₊₄ (100
℃) 76} 30g, reference example 3 as Tatsuki Fire
24 g of the resin obtained in Example 1, 9 of each of the polymers obtained in Example 4, and Comparative Example 2 as a softener.
g, and 250 g of toluene were mixed to prepare a solvent-type pressure-sensitive adhesive. Apply each of these adhesives onto a polyester film using an applicator, and
The adhesive tape was prepared by drying at ℃ for 20 minutes. 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 invention, softener A
(An adhesive was prepared in the same manner as in Example 15 using "Sansen Oil 450" manufactured by Sun Oil Co., Ltd., and the adhesive performance was evaluated. Comparative Example 14 Instead of using the polymer of the present invention, a softening agent was used. B
("Ciel Flex 371N" manufactured by Ciel Chemical Co., Ltd.), an adhesive was prepared in the same manner as in Example 15, and the adhesive performance 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.

【table】

Claims (1)

[Claims] 1 Obtained by copolymerizing unsaturated hydrocarbon A and 9,10-dihydrodicyclopentadiene or its derivatives, the monomer units of A in the copolymer are 20 to 98 mol%, and the monomer units of B are 80 to 98 mol%. An additive for pressure-sensitive adhesives comprising a hydrocarbon polymer with a softening point of less than 60° C. and a softening point of less than 60° C.