JP2762209B2 - Method for producing hydrogenated petroleum resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hydrogenated petroleum resin having good heat stability and excellent tackiness, which can be effectively used as a tackifier in a pressure-sensitive adhesive. .

[0002]

2. Description of the Related Art Pressure-sensitive adhesives and hot-melt adhesives are mainly composed of a thermoplastic resin or synthetic rubber as an adhesive, and a tackifier is added to the adhesive, if necessary. Furthermore, it is manufactured by blending various plasticizers and fillers.

As a method for producing a hydrogenated petroleum resin (hereinafter sometimes abbreviated as a hydrogenated petroleum resin) known as a tackifier, a cyclopentadiene compound and a vinyl-substituted aromatic hydrocarbon such as styrene are used. And a method of producing the polymer by further hydrogenating the resulting polymer.

[0004] However, the hydrogenated petroleum resin produced by this conventional method has room for improvement in thermal stability, compatibility and adhesive performance when used as a tackifier. That is, the ethylene-vinyl acetate copolymer as the main adhesive,
A pressure-sensitive adhesive using a hydrogenated petroleum resin produced by a conventional method as a tackifier has poor heat stability and compatibility. In addition, an adhesive using a synthetic rubber as an adhesive main agent and a hydrogenated petroleum resin produced by a conventional method as a tackifier has the disadvantage that tack and adhesive strength are weak.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to improve the performance of these hydrogenated petroleum resins as a tackifier, and as a result, the hydrogenated petroleum resin was identified in the presence of a radical polymerization initiator. It has been found that by polymerizing at a temperature of, a hydrogenated petroleum resin which is excellent in thermal stability and compatibility, and which can be a tackifier having excellent tack and adhesive strength can be obtained.
The present invention has been completed based on this finding.

That is, the present invention provides a method for producing a hydrogenated petroleum resin by producing a hydrogenated petroleum resin by polymerizing a cyclopentadiene compound and a vinyl-substituted aromatic compound and then subjecting the resulting polymer to a hydrogenation reaction. It is intended to provide a method for producing a hydrogenated petroleum resin, which comprises conducting a polymerization reaction at a temperature of 200 to 350 ° C. in the presence of an agent.

The cyclopentadiene compound used as one of the raw materials in the present invention includes, for example, cyclopentadiene, methylcyclopentadiene, ethylcyclopentadiene, dimers and trimers thereof, and co-dimers thereof. Among them, cyclopentadiene and dicyclopentadiene are particularly preferred.

On the other hand, examples of the vinyl-substituted aromatic compound used as the other raw material include styrene, α-methylstyrene, β-methylstyrene, vinyltoluene and the like.

The proportion of these raw materials used is usually 10 to 90% by weight of the vinyl-substituted aromatic compound with respect to 90 to 10% by weight of the cyclopentadiene compound, preferably 70 to 30% by weight of the cyclopentadiene compound. % To 30% by weight of the vinyl-substituted aromatic compound. It is not preferable that the ratio be outside this range, since the adhesive performance of the obtained polymer is reduced. In particular, when the use ratio of the vinyl-substituted aromatic compound is large, the tackiness of the pressure-sensitive adhesive decreases, which is not preferable.

In the present invention, these cyclopentadiene compounds and vinyl-substituted aromatic compounds are used as raw materials.
Perform polymerization. As for the polymerization conditions, first, the polymerization temperature was set to 1
The temperature must be 50 to 350 ° C, preferably 200 to 300 ° C. Here, when the polymerization temperature is lower than 150 ° C., the adhesive performance of the obtained polymer is inferior and the polymerization time is undesirably long. On the other hand, the polymerization temperature is 350 ° C.
If it exceeds, the color of the obtained polymer is unfavorably deteriorated.

The polymerization time can be appropriately determined according to the type of the raw material, the polymerization temperature, and the desired properties of the hydrogenated petroleum resin. The polymerization time is usually 0.5 to 8 hours,
Preferably it is 1 to 5 hours, more preferably 1 to 3 hours. If the polymerization time is too short, the yield decreases, while if the polymerization time is too long, the color of the obtained polymer deteriorates. Further, the polymerization pressure generally requires a pressure sufficient for the reaction system to be in a liquid phase, and is usually 0 to 30 kg / cm ² G, preferably 5 to 20 kg / cm ² G.
It is.

In the present invention, it is indispensable to carry out the above-mentioned polymerization reaction using a radical polymerization initiator. Here, there are various radical polymerization initiators, but those having a 10-hour half-life temperature of 50 ° C. or more are preferable.

As such a radical polymerization initiator,
For example, 2,3-dimethyl-2,3-diphenylbutane (trade name: NOFMER BC, manufactured by NOF Corporation) (10-hour half-life temperature = about 220 ° C., in the following examples, the number in parentheses is 10 hours The half-life temperature is shown.), 2,
Hydroper such as 4,4-trimethylpentyl-2-hydroperoxide (135 ° C), diisopropylbenzene hydroperoxide (150 ° C), cumene hydroperoxide (159 ° C), t-butyl hydroperoxide (171 ° C) Oxides, dialkyl peroxides such as dicumyl peroxide (117 ° C.), t-butylcumyl peroxide (121 ° C.), di-t-butyl peroxide (126 ° C.), t
Alkyl peresters such as -butylperoxypivalate (56 ° C.) and t-butylperoxy-2-ethylhexinoate (74 ° C.); and diacyl peroxides such as benzoyl peroxide (72 ° C.). No.

Such a radical polymerization initiator is usually added at a ratio of 0.02 to 5.0% by weight, preferably 0.1 to 3.0% by weight, based on the above-mentioned raw materials. Is done.

The polymerization is usually carried out in the presence of a solvent, and examples of the solvent used in this case include an aromatic solvent, a naphthene solvent and a paraffin solvent. Of these, aromatic solvents are preferable, and benzene, toluene, and xylene are particularly preferable.

In the present invention, the polymer obtained in this manner is subjected to a hydrogenation reaction (hydrogenation reaction) after removing volatile components by a conventional method to produce a desired hydrogenated petroleum resin. I do. Here, as a catalyst for the hydrogenation reaction,
For example, a nickel-based catalyst, a palladium-based catalyst, a cobalt-based catalyst, a platinum-based catalyst, a rhodium-based catalyst, and the like can be used, and a platinum-based catalyst, a nickel-based catalyst, and a palladium-based catalyst are particularly preferable.

Regarding the hydrogenation reaction conditions, first, the reaction temperature is 120 to 300 ° C., preferably 150 to 250 ° C.
° C. If the reaction temperature is too low, the reaction takes time,
On the other hand, if the reaction temperature is too high, a part of the obtained polymer may be subject to hydrogenolysis. Next, the reaction pressure is usually 20 to 150 kg / cm ² G, preferably 30 to 100 kg.
/ cm ² G. Furthermore, the reaction time depends on the reaction temperature, pressure,
It can be appropriately selected depending on the degree of hydrogenation. Usually 1
The reaction is carried out for a period of up to 7 hours, preferably 2 to 6 hours.

The degree of hydrogenation is not more than 20 g / 100 g, preferably not more than 15 g / 100 g, more preferably not more than 10 g / 100 g, and the styrene content in the polymer after hydrogenation is 30% by weight. %, Preferably 28% by weight or less, more preferably 26% by weight or less.

The hydrogenation reaction is usually performed in the presence of a solvent. Examples of the solvent used at this time include naphthenic hydrocarbons, paraffinic hydrocarbons, ethers, ketones, esters and the like. Among them, cyclohexane, ethylcyclohexane,
Naphthenic hydrocarbons such as dimethylcyclohexane are preferred.

As described above, it is possible to obtain a hydrogenated petroleum resin which is excellent in thermal stability and compatibility and can be used as a tackifier having excellent tackiness and adhesive strength. The hydrogenated petroleum resin thus obtained is used as a tackifier in combination with an ethylene-vinyl acetate copolymer or synthetic rubber, which constitutes the main component, and various additives (plasticizer, filler, etc.). , Can be used as an adhesive.

[0021]

Next, the present invention will be described in detail with reference to examples. Examples 1 to 3 (1) Polymerization reaction 380 g of xylene as a solvent was introduced into a 1-liter autoclave, which was replaced with nitrogen and equipped with a stirrer, and heated to 240 ° C. Next, 160 g of dicyclopentadiene and 160 g of styrene were added to the autoclave.
g of the radical polymerization initiator [2,3
-Dimethyl-2,3-diphenylbutane (trade name: NOFMER BC, manufactured by NOF Corporation, 10-hour half-life temperature about 2
20 ° C.] was introduced over 2 hours while stirring, and then the temperature was raised to 260 ° C. to carry out the polymerization reaction for the time shown in Table 1. After the completion of the polymerization reaction, the reaction product was treated with a rotary evaporator at 200 ° C. and 10 Torr for 3 hours to remove unreacted monomers, low molecular weight polymers and xylene to obtain a cyclopentadiene-styrene copolymer. The styrene copolymerization ratio of each copolymer was 48% by weight.

(2) Hydrogenation reaction Then, the above (1) was placed in an autoclave having a capacity of 1 liter.
Cyclopentadiene-styrene copolymer 20 obtained in
0 g, solvent as cyclohexane 200 g, nickel catalyst as hydrogenation catalyst (Nikki Chemical Co., Ltd., sulfur-resistant nickel catalyst N-113) after the introduction of 4g, by introducing hydrogen, the pressure to 40 kg / cm ² G 230 ° C while keeping
For 3 hours to obtain a hydrogenated petroleum resin. Table 1 shows the physical properties (softening point, bromine value, and styrene content) of the obtained hydrogenated petroleum resin.

(3) Evaluation of Compatibility and Thermal Stability The hydrogenated petroleum resin obtained in the above (2) was mixed with the ethylene-vinyl acetate copolymer in the following ratio using a laboplast mill. The compatibility and thermal stability between the added petroleum resin and the ethylene-vinyl acetate copolymer were evaluated by measuring the cloud point and the surface skinning. The results are shown in Table 1.

[Ingredients] (parts by weight) Hydrogenated petroleum resin 50 Ethylene-vinyl acetate copolymer 15 [Tosoh Corporation, UE720, melt flow rate 150 g / 10 min, vinyl acetate content 28% by weight] Vinyl acetate copolymer 20 [manufactured by Tosoh Corporation, UE722, melt flow rate 400 g / 10 min, vinyl acetate content 28% by weight] Microcrystalline wax 10 [manufactured by Nippon Seiro Co., Ltd., Hi-Mic 3080, melting point 83 ℃] Paraffin wax 5 [Sazol H1 manufactured by South Africa Public Corporation]

(4) Evaluation of Adhesive Performance The hydrogenated petroleum resin obtained in the above (2) and styrene-
The butadiene-styrene copolymer was mixed at the following ratio using a Labo Plastomill, and the adhesive strength and tack were measured and evaluated. The results are shown in Table 1.

[Ingredients] (parts by weight) Hydrogenated petroleum resin 60 Styrene-butadiene-styrene block copolymer 25 [manufactured by Shell Japan K.K., TRKX-65, styrene content 28% by weight, Meltindex 6g / 10min (200 ° C, 5 kg)] Process oil 15 [Diana Process Oil PS-32, manufactured by Idemitsu Kosan Co., Ltd.] Hindered phenolic antioxidant 1.0 [Circa Geigy, Inc., Irganox 1010]

Comparative Examples 1 to 3 Hydrogenated petroleum resins were obtained in the same manner as in Example 1 except that the polymerization time at 260 ° C. was as shown in Table 1 without using a radical polymerization agent. The physical properties are shown in Table 1. The copolymerization ratio of styrene before hydrogenation of the hydrogenated petroleum resin was 48% by weight in each case. Then, in the same manner as in Example 1, the cloud point and surface skinning were measured for the mixture of the hydrogenated petroleum resin and the ethylene-vinyl acetate copolymer, and the mixture was further treated with a styrene-butadiene-styrene block copolymer. The mixture was measured for adhesion and tack. The results are shown in Table 1.

[0028]

[Table 1]

[Footnote to Table 1] * 1: Softening point = Measured based on the hot melt adhesive test method JAI7 of the Japan Adhesive Industry Association Standard. * 2: Bromine value was measured according to JIS-2605. * 3: Styrene content was analyzed by infrared absorption spectroscopy. The solvent used was carbon disulfide, and the styrene content was determined from the absorbance at a wave number of 700 cm ^-1 . * 4: Skinning = measured according to the hot melt adhesive test method JAI7 of the Japan Adhesive Industry Association Standard. The heating was performed in a sample container at 180 ° C. for 48 hours. The measurement results are shown in terms of the area of the film formed on the sample surface as a percentage of the area of the sample surface. * 5: Adhesion = hydrogenated petroleum resin and styrene-butadiene
A solution prepared by dissolving 100 parts by weight of a mixture with a styrene block copolymer in 60 parts by weight of toluene is applied to a polyethylene terephthalate film, and heated at 100 ° C. for 1.5 minutes to form an adhesive layer having a thickness of 40 to 50 μm. An adhesive tape was prepared. This adhesive tape was attached to a polyethylene plate, and the adhesive strength was measured by a 180-degree peeling method according to JIS-Z-0237. * 6: Tack = Measured with a loop tack having a width of 25 mm and a loop length of 10 cm using the pressure-sensitive adhesive tape prepared by the above-described method of measuring the adhesive strength of * 5.

Example 4 A radical polymerization initiator was added in the amounts shown in Table 2 and the polymerization time at 260 ° C. was as shown in Table 2.
A hydrogenated petroleum resin was obtained in the same manner as in Example 1. The physical properties are shown in Table 2. The copolymerization ratio of styrene before hydrogenation of this hydrogenated petroleum resin was 48% by weight. Then, in the same manner as in Example 1, the adhesive strength and tack of the mixture of the hydrogenated petroleum resin and the styrene-butadiene-styrene block polymer were measured. The results are shown in Table 2.

Comparative Examples 4 and 5 A hydrogenated petroleum resin was obtained in the same manner as in Example 1 except that the radical polymerization initiator was not used and the polymerization time at 260 ° C. was as shown in Table 2. The physical properties are shown in Table 2. In addition, the copolymerization ratio of styrene before hydrogenation of this hydrogenated petroleum resin was 48% by weight. Then, the hydrogenated petroleum resin and styrene-butadiene-
The adhesive strength and tack of the mixture with the styrene block polymer were measured. The results are shown in Table 2 together with the results of Example 3.

[0032]

[Table 2]

[Footnotes in Table 2] * 1 to 3 are the same as * 1 to 3 in Table 1. * 4 is the same as * 5 in Table 1. * 5 is the same as * 6 in Table 1.

[0034]

According to the method of the present invention, when used as a tackifier, water which can give a tacky adhesive which is excellent in heat stability and compatibility and also excellent in tack and adhesive strength. A petroleum resin can be produced.

──────────────────────────────────────────────────続 き Continued on the front page (72) Michihiro Kumagai 1-1, Shingu-cho, Tokuyama-shi, Yamaguchi Pref. Idemitsu Petrochemical Co., Ltd. (56) References JP-A-6-93015 (JP, A) −139709 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 8/00-8/04 C08F 212/00-212/36 C08F 232/00-232/08 C08F 240 / 00 C09J 157/00-157/02

Claims (1)

(57) [Claims] 1. A method for producing a hydrogenated petroleum resin by producing a hydrogenated petroleum resin by polymerizing a cyclopentadiene compound and a vinyl-substituted aromatic compound and then subjecting the resulting polymer to a hydrogenation reaction. Below 150 ~
A method for producing a hydrogenated petroleum resin, wherein a polymerization reaction is carried out at a temperature of 350 ° C.