JP6870365B2 - Hydrogenated styrene copolymer resin - Google Patents

Description

The present invention relates to a hydrogenated styrene-based copolymer resin, and is particularly excellent in compatibility with styrene-butadiene copolymer rubber (hereinafter referred to as SBR), so that it is excellent in compatibility with tires, anti-vibration rubbers, belts, hoses, and footwear. The present invention relates to a hydrogenated styrene-based copolymer resin that is excellent for SBR modification and can be used in various applications such as adhesives.

It has been proposed to add a resin to rubber for the purpose of improving tire performance and workability. A method of improving wet grip by blending a hydrogenated resin having high compatibility with rubber has been proposed (see, for example, Patent Documents 1 to 4). As the resin of the raw material to be hydrolyzed, a styrene resin, a petroleum resin obtained by polymerizing a C9 fraction, a petroleum resin obtained by copolymerizing a C5 fraction and a C9 fraction, and the like have been proposed. Patent Document 1 further proposes that an aromatic petroleum resin having an indene ratio of 40% by mass or more in the raw material is preferable.

To improve the initial grip and running stability of the tire, a hydrogenated resin consisting of a petroleum resin composed of C5 component and / or C9 component hydrogenated with a softening point of 120 ° C. or higher, and a softening point of 140 ° C. or higher and 190 ° C. or lower. It has been proposed to add an inden-containing C9 resin to the rubber component (see, for example, Patent Document 5).

Further, it has been proposed to hydrogenate a C9 resin having a monomer composition of 20% by weight or less of indene and 50% by weight or more of vinyltoluene and add it to a thermoplastic elastomer (see, for example, Patent Documents 6 and 7). Examples of the thermoplastic elastomer at that time include a styrene-butadiene copolymer.

Japanese Unexamined Patent Publication No. 2008-174696 Japanese Unexamined Patent Publication No. 2009-13825 Japanese Unexamined Patent Publication No. 2011-88888 Japanese Unexamined Patent Publication No. 2011-88898 Japanese Unexamined Patent Publication No. 2008-169298 Japanese Unexamined Patent Publication No. 11-335645 Japanese Unexamined Patent Publication No. 2000-104030

However, in the methods proposed in Patent Documents 1 to 5, the compatibility between rubber and resin is insufficient, the wet grip property is insufficient, and the rolling resistance is increased because a resin having a higher glass transition point than rubber is blended. However, there are problems such as deterioration of fuel efficiency, deterioration of workability due to high viscosity, limitation of the amount of silica and end-modified rubber used, and deterioration of tire performance due to poor kneading.

Further, in the methods proposed in Patent Documents 6 and 7, a hydrogenated C9 resin with a reduced amount of indene was added in order to improve the light resistance, and the effect of improving the compatibility was not mentioned at all. ..

Therefore, the present invention provides an excellent hydrogenated styrene-based copolymer resin for SBR modification, which can be used for tires, anti-vibration rubbers, belts, hoses, footwear, adhesives, etc. because of its excellent compatibility with SBR. The purpose is to do.

As a result of diligent research to solve the above problems, the present inventors have made it possible for a hydrogenated styrene-based copolymer resin obtained by copolymerizing a specific component to improve remarkable compatibility with SBR. This has led to the completion of the present invention.

That is, the present invention comprises at least one styrene-based derivative unit (A) 99 to 80% by weight selected from the group consisting of styrene, vinyltoluene, α-methylstyrene, and β-methylstyrene, and inden and methylinden. A styrene-based copolymer resin having at least 1 to 20% by weight of at least one derivative unit (B) selected from the group as a constituent unit is hydrogenated, and the hydrogenation rate of the aromatic ring is 70% or more. It relates to a hydrogenated styrene-based copolymer resin characterized by the above.

Hereinafter, the present invention will be described in detail.

The hydrogenated styrene-based copolymer resin of the present invention is obtained by hydrogenating a styrene-based copolymer resin, and the styrene-based copolymer resin is composed of styrene, vinyltoluene, α-methylstyrene, and β-methylstyrene. At least 99 to 80% by weight of at least one styrene-based derivative unit (A) selected from the group and at least 1 to 20% by weight of at least one derivative unit (B) selected from the group consisting of inden and methyl inden. It is a copolymer as a unit, and in particular, the hydrogenated product after hydrogenation has excellent compatibility with SBR and handleability. Therefore, the styrene-based derivative unit (A) is 95 to 85% by weight, which is a derivative unit. (B) It is preferable that the constituent unit is at least 5 to 15% by weight. Here, when the styrene-based derivative unit (A) is less than 80% by weight, or exceeds 99% by weight, the compatibility with SBR is inferior.

The hydrogenated styrene-based copolymer resin of the present invention is obtained by hydrogenating a styrene-based copolymer resin, and at the time of hydrogenation, hydrogenation of the aromatic ring mainly constituting the styrene-based copolymer resin proceeds. To do. Since it is a hydrogenated styrene-based copolymer resin having excellent compatibility with SBR, the hydrogenation rate of the aromatic ring is 70% or more, and the hydrogenation rate is 80% or more. Is preferable. When the hydrogenation rate is less than 70%, the compatibility with SBR is inferior.

Since the hydrogenated styrene-based copolymer resin of the present invention has particularly excellent compatibility with SBR, the weight average molecular weight (Mw) when measured as a standard polystyrene equivalent value using gel permeation chromatography is 800. The one of about 3000 is preferable, and the one of 800 to 2000 is more preferable.

Further, the hydrogenated styrene-based copolymer resin of the present invention is particularly excellent in compatibility with SBR and processability, and therefore has a softening point of 70 to 140 ° C. in accordance with JIS K-2207. Is preferable, and more preferably 80 to 130 ° C.

The hydrogenated styrene-based copolymer resin of the present invention contains the styrene-based derivative unit (A) and the unit (C) other than the derivative unit (B) within a range that does not adversely affect the compatibility with SBR. It may be included. Examples of the unit (C) at that time include units derived from C5 monomers such as dicyclopentadiene and its derivatives, isoprene, piperylene, and cyclopentadiene.

The styrene-based copolymer used for hydrogenation when the hydrogenated styrene-based copolymer resin of the present invention is used is any as long as it can be used as the hydrogenated styrene-based copolymer resin of the present invention. It may be composed of, for example, 99 to 80% by weight of at least one styrene-based monomer (a) selected from the group consisting of styrene, vinyltoluene, α-methylstyrene, and β-methylstyrene, and inden and methylinden. It can be obtained by subjecting a monomer containing at least 1 to 20% by weight of at least one monomer (b) selected from the group to copolymerization. In that case, for example, a monomer (c) derived from a C5 monomer such as dicyclopentadiene and its derivative, isoprene, piperylene, and cyclopentadiene can be copolymerized within a range that does not cause a problem.

As a method for preparing the monomer composition of the raw material oil (monomer mixture) at the time of copolymerization, for example, a method of mixing using pure monomers and a boiling point range obtained by thermal decomposition of petroleums are available. Examples thereof include a method of distilling and purifying a C9 fraction in the range of 140 to 280 ° C., a method of mixing a pure monomer and a C9 fraction, and the like. The C9 distillate generally contains a monomer such as the styrene-based monomer (a), the monomer (b), dicyclopentadiene and a derivative thereof, and generally contains the styrene-based monomer. Since the proportion of the monomer (b) in the total amount of the monomer (a) and the monomer (b) is as large as 30 to 45% by weight, hydrogenated C9-based petroleum resin is hydrogenated with hydrogenated C9-based petroleum. The resin is inferior in compatibility with SBR. Further, the hydrogenated C9-based petroleum resin is also different in composition from the hydrogenated styrene-based copolymer resin of the present invention.

Examples of the polymerization reaction for obtaining the styrene-based copolymer resin include a cationic polymerization method using a Friedel-Crafts type catalyst, and examples of the Friedel-Crafts type catalyst include aluminum trifluoride and triodorization. Examples thereof include aluminum, boron trifluoride, these phenol complexes, and these butanol complexes, and among them, boron trifluoride phenol complex and boron trifluoride butanol complex are preferable. The polymerization temperature is preferably 0 to 100 ° C, particularly preferably 0 to 80 ° C. Further, the amount of the Friedel-Crafts type catalyst added is arbitrary, and among them, since it is a production method having particularly excellent production efficiency, it is 0.1 to 2.0 parts by weight with respect to 100 parts by weight of the mixture. It is preferable to have. Further, the polymerization time is preferably in the range of 0.1 to 10 hours. The reaction pressure is preferably atmospheric pressure to 1 MPa.

The hydrogenated styrene-based copolymer resin of the present invention can be produced by hydrogenating the styrene-based copolymer resin in the presence of a hydrogenation catalyst by a known method. Examples of the hydrogenation catalyst include oxides such as nickel, cobalt, ruthenium, rhodium, palladium, platinum and molybdenum, and metal compounds such as sulfide, which are porous and have a large surface area such as diatomaceous earth, alumina, silica, carbon and titania. It may be carried on a carrier such as.

As for the conditions of the hydrogenation reaction, the hydrogen pressure, temperature, amount of catalyst, and amount of solvent used may be appropriately adjusted so as to obtain a desired hydrogenation rate.

The hydrogenated styrene-based copolymer resin of the present invention may contain one or more other rubber components as long as the performance is not adversely affected. Examples of the rubber component include natural rubber, polyisoprene rubber, polybutadiene rubber, butyl rubber, ethylene-propylene copolymer and the like.

As the hydrogenated styrene-based copolymer resin of the present invention, additives usually blended in a resin composition or a rubber composition may be used. For example, add compounding agents such as cross-linking agents such as sulfur, vulcanization accelerators, vulcanization accelerator aids, stearic acid, zinc oxide, plasticizers, oils, anti-aging agents, and fillers such as silica and carbon black. Is also good. Commercially available products can be preferably used as these compounding agents. Furthermore, additives usually blended in resin compositions and rubber compositions, such as phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, lactone antioxidants, UV absorbers, pigments, calcium carbonate , Glass beads and the like may be blended.

INDUSTRIAL APPLICABILITY The present invention provides an excellent hydrogenated styrene-based copolymer resin for SBR modification that can be used in various applications such as tires, anti-vibration rubbers, belts, hoses, footwear, and adhesives because of its excellent compatibility with SBR. It becomes possible.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The raw materials, analysis, and test methods used in Examples and Comparative Examples are as follows.

1. 1. Raw material (1) Styrene-based copolymer resin Raw material Styrene; Wako Pure Chemicals' reagent.
Vinyl toluene; p-methylstyrene, Wako Pure Chemical's reagent.
α-Methylstyrene; Wako Pure Chemical's reagent.
Indene; Wako Pure Chemical's reagent.
Toluene; Wako Pure Chemical's reagent, ultra-dehydration grade.
C9 oil; C9 fraction with a boiling point range of 140-280 ° C. obtained by thermal decomposition of naphtha.
Refined C9 oil; Distilled and refined C9 oil.
The raw materials used for the polymerization were prepared so as to have a predetermined composition. The composition of the raw materials is shown in Table 1. DCPD in Table 1 is an abbreviation for dicyclopentadiene.
Polymerization catalyst; boron trifluoride phenol (manufactured by Stella Chemifa).

(2) Hydrogenation catalyst of styrene-based copolymer resin; palladium-barium sulfate (manufactured by Aldrich, 10% palladium).
Solvent: Cyclohexane (Wako Pure Chemicals Reagent)
2. Analytical method (1) Composition of raw material oil for styrene-based copolymer resin: Measured by gas chromatography in accordance with JIS K-0114 (2000).
(2) Softening point: Measured according to JIS K-2207.
(3) Molecular weight: Measured by gel permeation chromatography using polystyrene as a standard substance.
^{(4) Hydrogenation rate: 1} H-NMR spectrum was measured in deuterated chloroform with a nuclear magnetic resonance measuring device (manufactured by JEOL Ltd., trade name: JNM-ECZ400S / LI, frequency 400 MHz), and a peak derived from an aromatic around 7 ppm. Based on the area, the hydrogenation rate was calculated by the following formula.
Hydrogenation rate = (1- (peak area of hydrogenated resin / peak area of raw material resin)) × 100 (%).
(5) Compatibility: Using a viscoelasticity measuring device (manufactured by Leometrics), measure tan δ at a temperature of -100 to 100 ° C., a heating rate of 2 ° C./min, a frequency of 10 Hz, and a shear mode, and the peak value of tan δ. (Height) was used as an index of compatibility. As a reference, the measured values (tan δ) of Comparative Examples 1 and 8 to which the hydrogenated styrene-based copolymer resin was not added were set as the reference value (100). It was judged that the larger the relative value with respect to the reference value, the better the compatibility.
Compatibility index = ((measured tan δ value) / (tan δ of Comparative Examples 1 and 8)) × 100
Production Example 1 (Preparation of raw material oil)
The raw material oils A to D shown in Table 1 were prepared to a predetermined concentration using commercially available raw materials. As the raw material oil E, a C9 fraction having a boiling point range of 140 to 280 ° C. obtained by thermal decomposition of naphtha was used as it was. The raw material oil F was refined by distilling the raw material oil E and removing mainly the high boiling point fraction. The composition of the feedstock oil is shown in Table 1.

Production Example 2 (Production of styrene-based copolymer)
500 g of the raw material oil shown in Table 1 was charged into a glass autoclave having an internal volume of 2 liters. Next, after heating to 40 ° C. in a nitrogen atmosphere, a boron trifluoride phenol complex (Stellachemifa Co., Ltd. boron trifluoride phenol) was added as a Friedel-Crafts type catalyst to 100 parts by weight of the raw material oil. 8 parts by weight was added and polymerized at 80 ° C. for 2 hours. After adding the caustic soda aqueous solution, the aqueous phase was removed.

Then, 400 g of the obtained oil phase was added to a 0.5 liter separable flask equipped with a nitrogen introduction tube, a thermometer and a degassing tube. Nitrogen was introduced from a nitrogen introduction tube at a flow rate of 7 ml / min, the temperature was raised to 220 ° C. over 30 minutes, and then the mixture was further heated for 30 minutes to distill and remove unreacted oil to obtain a styrene-based copolymer resin.

The styrene-based copolymer resins obtained by using the raw material oils A to F were designated as resins A to F, respectively. Table 2 shows the polymerization yield and the physical properties (molecular weight, softening point) of the resins A to F.

Example 1
100 g of resin A, 5% by weight of a palladium-barium sulfate catalyst as a hydrogenation catalyst, and 100 g of cyclohexane were added to a 1 L autoclave. The temperature was raised to 250 ° C., and hydrogenation was carried out at a hydrogen pressure of 10 MPa for 6 hours.

After hydrogenation, the hydrogenation catalyst is removed by filtration, and the obtained hydrogenated styrene-based copolymer resin solution is added to a 1-liter separable flask equipped with a nitrogen introduction tube, a thermometer and a degassing tube to introduce hydrogen. Nitrogen was introduced from the tube at a flow rate of 7 ml / min, the temperature was raised to 220 ° C. over 30 minutes, and then heated for another 30 minutes to distill off cyclohexane to obtain a hydrogenated styrene-based copolymer resin A1.

Table 3 shows the hydrogenation reaction conditions and the physical characteristics (hydrogenation rate, molecular weight, softening point) of the obtained hydrogenated styrene-based copolymer resin A1.

Then, in a vial (20 ml), 100 parts by weight of a solution-polymerized terminal-modified styrene-butadiene copolymer rubber (SBR1) (manufactured by JSR Co., Ltd., (trade name) SL552) and hydride styrene copolymer resin A1 are placed. In addition to 30 parts by weight, it was dissolved in 1000 parts by weight of toluene using a stirrer. The solution was cast on an aluminum cup, pre-dried under a nitrogen stream, and then vacuum dried at 60 ° C.

The compatibility of the obtained SBR formulation was measured. The results are shown in Table 4.

Examples 2-4
Hydrogenated styrene-based copolymer resins (A2, B1, B2) were obtained by the same method as in Example 1 except that the type of resin and the amount of hydrogenation catalyst were as shown in Table 3.

Table 3 shows the hydrogenation reaction conditions and the physical characteristics (hydrogenation rate, molecular weight, softening point) of the obtained hydrogenated styrene-based copolymer resin (A2, B1, B2).

An SBR compound was obtained by the same method as in Example 1 except that the hydrogenated styrene-based copolymer resin (A2, B1, B2) was used instead of the hydrogenated styrene-based copolymer resin A1. The results are shown in Table 4.

Examples 5 and 6
Hydrogenated styrene-based copolymer resins (F1, F2) were obtained by the same method as in Example 1 except that the type of resin and the amount of hydrogenation catalyst were as shown in Table 3.

Table 3 shows the hydrogenation reaction conditions and the physical characteristics (hydrogenation rate, molecular weight, softening point) of the obtained hydrogenated styrene-based copolymer resin (F1, F2).

Instead of the end-unmodified styrene-butadiene copolymer rubber (SBR1) of the solution polymer (manufactured by JSR Co., Ltd., (trade name) SL552), the end-modified styrene-butadiene copolymer rubber (SBR2) of the solution polymer (Product name: HPR350 manufactured by JSR Co., Ltd.) was used, and the hydrogenated styrene-based copolymer resin (F1, F2) was used instead of the hydrogenated styrene-based copolymer resin A1. An SBR formulation was obtained by the same method. The results are shown in Table 5.

Comparative Example 1
Evaluation was carried out by the same method as in Example 1 using only SBR1 without using the hydrogenated styrene-based copolymer resin A1. The results are shown in Table 4.

Comparative Examples 2-7
Hydrogenated copolymer resins (A3, B3, C1, C2, D1, D2) were prepared in the same manner as in Example 1 except that the type of resin, the amount of hydrogenation catalyst, and the hydrogenation time were as shown in Table 3. ) Was obtained.

Table 3 shows the hydrogenation reaction conditions and the physical characteristics (hydrogenation rate, molecular weight, softening point) of the obtained hydrogenated copolymer resin (A3, B3, C1, C2, D1, D2).

An SBR compound was obtained by the same method as in Example 1 except that the hydrogenated styrene-based copolymer resin A1 was replaced with the hydrogenated copolymer resin (A3, B3, C1, C2, D1, D2). .. The results are shown in Table 4.

Comparative Example 8
Evaluation was performed using only SBR2. The results are shown in Table 5.

Comparative Examples 9 to 12
An SBR compound was obtained by the same method as in Example 5 except that the hydrogenated copolymer resin F1 was replaced with the hydrogenated copolymer resin (E1, E2, E3, F3). The results are shown in Table 5.

The hydrogenated styrene-based copolymer resin of the present invention is excellent for modifying styrene-butadiene rubber (SBR), and is particularly excellent in compatibility with SBR, so that tires, anti-vibration rubbers, belts, hoses, and footwear , Can be used for adhesives, etc., and its industrial value is extremely high.

Claims (4)

At least one selected from the group consisting of styrene, α-methylstyrene and β-methylstyrene, or a styrene-based derivative unit (A) containing 99 to 80% by weight of vinyl toluene and selected from the group consisting of inden and methyl inden. A styrene-based copolymer resin having at least 1 to 20% by weight of at least one derivative unit (B) as a constituent unit is hydrogenated, and the hydrogenation rate of the aromatic ring is 70% or more. Hydrogenated styrene-based copolymer resin. The hydrogenated styrene-based copolymer resin according to claim 1, wherein the weight average molecular weight in terms of standard polystyrene by gel permeation chromatography is 800 to 3000. The hydrogenated styrene-based copolymer resin according to claim 1 or 2, wherein the softening point according to JIS K-2207 is 70 to 140 ° C. A styrene-butadiene copolymer rubber modifier, which comprises the hydrogenated styrene-based copolymer resin according to any one of claims 1 to 3.