JP2018131515A - Hydrogenated styrene-based copolymer resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogenated styrene-based copolymer resin excellent as SBR modification because of excellent in compatibility with SBR.SOLUTION: A hydrogenated styrene-based copolymer resin is obtained by hydrogenation of a styrene-based copolymer resin containing at least 99-80 wt.% of at least one styrene derivative unit (A) selected from the group consisting of styrene, vinyl toluene, α-methyl styrene and β-methyl styrene and 1-20 wt.% of at least one derivative unit (B) selected from the group consisting of indene and methyl indene as constitutional units, where a hydrogenation rate of the aromatic ring is 70% or more.SELECTED DRAWING: None

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 can be used for tires, anti-vibration rubbers, belts, hoses and footwear. The present invention relates to a hydrogenated styrene copolymer resin that is excellent for SBR modification that can be used in various applications such as adhesives.

  In order to improve tire performance and workability, it has been proposed to blend a resin with rubber. A method of improving wet grip properties by blending a highly compatible hydrogenated resin with rubber has been proposed (see, for example, Patent Documents 1 to 4). As a raw material resin to be hydrogenated, 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 suggests that an aromatic petroleum resin having a ratio of indene in the raw material of 40% by mass or more is preferable.

  For improving the initial grip and running stability of a tire, a hydrogenated resin having a softening point of 120 ° C. or higher obtained by hydrogenating a petroleum resin comprising a C5 component and / or a C9 component, and further having a softening point of 140 ° C. or higher and 190 ° C. or lower. It has been proposed to blend C9 resin containing indene into a rubber component (see, for example, Patent Document 5).

  In addition, 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). As the thermoplastic elastomer at that time, for example, a styrene-butadiene copolymer is mentioned.

JP 2008-174696 A JP 2009-138025 A JP 2011-89888 A JP 2011-88998 A JP 2008-169298 A JP 11-335645 A JP 2000-104030 A

  However, the methods proposed in Patent Documents 1 to 5 have insufficient compatibility between the rubber and the resin, the wet grip property is insufficient, and the rolling resistance is increased because the resin has a glass transition point higher than that of the rubber. However, the fuel efficiency deteriorates, the viscosity increases, the workability deteriorates, the amount of silica and terminal-modified rubber used is limited, and the tire performance deteriorates due to poor kneading.

  In addition, in the methods proposed in Patent Documents 6 and 7, hydrogenated C9 resin with a reduced amount of indene is added to improve light resistance, and no mention is made of the effect of improving compatibility. .

  Accordingly, the present invention provides a hydrogenated styrene copolymer resin that is excellent for SBR modification and can be used for tires, anti-vibration rubbers, belts, hoses, footwear, adhesives and the like because of its excellent compatibility with SBR. It is intended to do.

  As a result of diligent research to solve the above-mentioned problems, the inventors of the present invention can improve the marked compatibility of the hydrogenated styrene copolymer resin obtained by copolymerizing specific components with SBR. As a result, the present invention has been completed.

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

  The present invention is described in detail below.

  The hydrogenated styrene copolymer resin of the present invention is obtained by hydrogenating a styrene copolymer resin, and the styrene copolymer resin comprises styrene, vinyltoluene, α-methylstyrene, and β-methylstyrene. At least one styrene derivative unit (A) selected from the group of 99 to 80% by weight and at least one derivative unit (B) selected from the group consisting of indene and methylindene constitute at least 1 to 20% by weight Since the hydrogenated product after hydrogenation has excellent compatibility with SBR and excellent handleability, the styrene derivative unit (A) is 95 to 85% by weight and the derivative unit. (B) It is preferable that 5 to 15% by weight is at least a structural unit. Here, when the styrene derivative unit (A) is less than 80% by weight, or when it exceeds 99% by weight, the compatibility with SBR is poor.

  The hydrogenated styrene copolymer resin of the present invention is obtained by hydrogenating a styrene copolymer resin, and during the hydrogenation, hydrogenation of the aromatic ring mainly constituting the styrene copolymer resin proceeds. To do. And since it becomes a hydrogenated styrene copolymer resin excellent in compatibility with SBR in particular, the hydrogenation rate of the aromatic ring is 70% or more, and the hydrogenation rate is 80% or more. It is preferable. When the hydrogenation rate is less than 70%, the compatibility with SBR is poor.

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

  The hydrogenated styrene 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. based on JIS K-2207. Are preferred, and those having a temperature of 80 to 130 ° C. are preferred.

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

  The styrene copolymer resin used for hydrogenation when the hydrogenated styrene copolymer resin of the present invention is used is not limited as long as it can be the hydrogenated styrene copolymer resin of the present invention. For example, at least one styrenic monomer (a) selected from the group consisting of styrene, vinyltoluene, α-methylstyrene, β-methylstyrene, 99 to 80% by weight, and indene and methylindene. It can be obtained by subjecting a monomer containing at least one monomer (b) 1 to 20% by weight selected from the group to copolymerization. In that case, for example, a monomer (c) derived from a C5 monomer such as dicyclopentadiene and derivatives thereof, isoprene, piperylene, cyclopentadiene, etc. can be copolymerized within a range where there is no problem.

  And as a method of preparing the monomer composition of the raw material oil (monomer mixture) at the time of copolymerization, for example, the method of mixing using pure monomers, the boiling point range obtained by pyrolysis of petroleums Examples 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 fraction generally contains monomers such as the styrenic monomer (a), the monomer (b), dicyclopentadiene, and derivatives thereof. Since the proportion of the monomer (b) in the total amount of (a) and the monomer (b) is as high as 30 to 45% by weight, hydrogenated C9 petroleum obtained by hydrogenating a C9 petroleum resin The resin is inferior in compatibility with SBR. Further, the hydrogenated C9 petroleum resin is also different in composition from the hydrogenated styrene copolymer resin of the present invention.

  Examples of the polymerization reaction for obtaining the styrene copolymer resin include a cationic polymerization method using a Friedel-Crafts type catalyst. Examples of the Friedel-Crafts type catalyst include aluminum trichloride and tribromide. Aluminum, boron trifluoride, these phenol complexes, these butanol complexes, etc. are mentioned, Among these, a boron trifluoride phenol complex and a boron trifluoride butanol complex are preferable. The polymerization temperature is preferably from 0 to 100 ° C, particularly preferably from 0 to 80 ° C. Further, the amount of the Friedel-Crafts-type catalyst added is arbitrary, and among them, the production method is particularly excellent in production efficiency, so 0.1 to 2.0 parts by weight with respect to 100 parts by weight of the mixture. Preferably there is. Furthermore, 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 copolymer resin of the present invention can be produced by hydrogenating the styrene copolymer resin by a known method in the presence of a hydrogenation catalyst. Examples of the hydrogenation catalyst include nickel, cobalt, ruthenium, rhodium, palladium, platinum, molybdenum and other metal compounds such as sulfides, and porous, large surface area diatomaceous earth, alumina, silica, carbon, titania. It may be supported on a carrier such as.

  The conditions for the hydrogenation reaction may be adjusted as appropriate so that the hydrogen pressure, temperature, amount of catalyst, and amount of solvent used are adjusted to achieve a desired hydrogenation rate.

  The hydrogenated styrenic 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.

  The hydrogenated styrene copolymer resin of the present invention may further use an additive that is usually blended in a resin composition or a rubber composition. For example, by adding compounding agents such as sulfur and other crosslinking agents, vulcanization accelerators, vulcanization acceleration aids, stearic acid, zinc white, plasticizers, oils, anti-aging agents, silica and carbon black fillers, etc. Also good. Commercial products can be suitably used as these compounding agents. Furthermore, additives usually incorporated in resin compositions and rubber compositions, such as phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, lactone antioxidants, UV absorbers, pigments, calcium carbonate Glass beads may be blended.

  The present invention provides a hydrogenated styrene copolymer resin that is excellent for SBR modification and 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. Raw material (1) Styrene copolymer resin raw material styrene; Reagent made by Wako Pure Chemical Industries.
Vinyl toluene; p-methylstyrene, a reagent manufactured by Wako Pure Chemical Industries.
α-methylstyrene; a reagent manufactured by Wako Pure Chemical Industries.
Inden: Wako Pure Chemicals reagent.
Toluene: Wako Pure Chemicals reagent, ultra-dehydrated grade.
C9 oil: C9 fraction having a boiling point range of 140 to 280 ° C. obtained by thermal decomposition of naphtha.
Refined C9 oil: Distilled and refined C9 oil.
The raw material used for superposition | polymerization was prepared so that it might become a predetermined composition. Table 1 shows the composition of the raw materials. In Table 1, DCPD is an abbreviation for dicyclopentadiene.
Polymerization catalyst; boron trifluoride phenol (manufactured by Stella Chemifa).

(2) Hydrogenation catalyst for styrene copolymer resin; palladium-barium sulfate (Aldrich, 10% palladium).
Solvent: Cyclohexane (Wako Pure Chemicals Reagents)
2. Analysis method (1) Composition of raw material oil for styrene-based copolymer resin: Measured by gas chromatography in accordance with Gas Chroma 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 with a nuclear magnetic resonance measuring apparatus (manufactured by JEOL, trade name JNM-ECZ400S / LI, frequency 400 MHz) in deuterated chloroform, and an aromatic-derived peak near 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 apparatus (manufactured by Rheometrics), 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 a peak value of tan δ (Height) was used as an indicator of compatibility. As a reference, the measured value (tan δ) of Comparative Examples 1 and 8 to which no hydrogenated styrene copolymer resin was added was set as a reference value (100). The greater 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 oil)
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 feedstock F was refined by distilling the feedstock E and removing mainly high-boiling fractions. Table 1 shows the composition of the feedstock oil.

Production Example 2 (Production of styrene 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, 0.03 parts by weight of boron trifluoride phenol complex (Stella Chemifa Co., Ltd., boron trifluoride phenol) as a Friedel-Crafts type catalyst is added to 0.1 parts by weight of the raw material oil. 8 parts by weight was added and polymerization was carried out at 80 ° C. for 2 hours. After adding the aqueous sodium hydroxide 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 deaeration tube. Nitrogen was introduced from the nitrogen introduction tube at a flow rate of 7 ml / min, the temperature was raised to 220 ° C. over 30 minutes, and the mixture was further heated for 30 minutes to distill off unreacted oil to obtain a styrene copolymer resin.

  Styrenic copolymer resins obtained using 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 was added to a 1 L autoclave, 5% by weight of a palladium-barium sulfate catalyst as a hydrogenation catalyst with respect to resin A, and 100 g of cyclohexane were added. The temperature was raised to 250 ° C., and hydrogenation was performed at a hydrogen pressure of 10 MPa for 6 hours.

  After hydrogenation, the hydrogenation catalyst is removed by filtration, and the hydrogenated styrene copolymer resin solution obtained is added to a 1-liter separable flask equipped with a nitrogen introduction tube, thermometer and deaeration tube, and nitrogen is introduced. 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 the mixture was further heated for 30 minutes to distill off cyclohexane to obtain hydrogenated styrene copolymer resin A1.

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

  Then, 100 parts by weight of hydrogenated styrene copolymer resin A1 and terminal polymer unmodified styrene-butadiene copolymer rubber (SBR1) (manufactured by JSR Co., Ltd., (trade name) SL552) are placed in a vial (20 ml). 30 parts by weight was added and 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
A hydrogenated styrene copolymer resin (A2, B1, B2) was obtained in the same manner as in Example 1 except that the type of resin and the amount of the hydrogenation catalyst were as shown in Table 3.

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

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

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

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

  Instead of the solution-modified end-modified styrene-butadiene copolymer rubber (SBR1) (manufactured by JSR, (trade name) SL552), the solution-polymerized end-modified styrene-butadiene copolymer rubber (SBR2) Example 1 except that hydrogenated styrene copolymer resins (F1, F2) were used instead of hydrogenated styrene copolymer resin A1 (made by JSR Corporation, (trade name) HPR350). An SBR formulation was obtained in a similar manner. The results are shown in Table 5.

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

Comparative Examples 2-7
A hydrogenated copolymer resin (A3, B3, C1, C2, D1, D2) was 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. )

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

  An SBR formulation was obtained in the same manner as in Example 1 except that the hydrogenated copolymer resin (A3, B3, C1, C2, D1, D2) was used instead of the hydrogenated styrene copolymer resin A1. . 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 9-12
An SBR formulation was obtained in the same manner as in Example 5 except that the hydrogenated copolymer resin (E1, E2, E3, F3) was used instead of the hydrogenated copolymer resin F1. The results are shown in Table 5.

  The hydrogenated styrene copolymer resin of the present invention is excellent for modifying styrene-butadiene rubber (SBR), and particularly excellent in compatibility with SBR, so that it is tire, vibration-proof rubber, belt, hose, footwear. It can be used for adhesives and the like, and its industrial value is extremely high.

Claims (4)

  At least one styrenic derivative unit (A) selected from the group consisting of styrene, vinyltoluene, α-methylstyrene, β-methylstyrene (A) 99-80 wt% and at least selected from the group consisting of indene and methylindene Hydrogenation characterized by hydrogenating a styrene copolymer resin containing at least 1 to 20% by weight of one derivative unit (B) as a structural unit, and the hydrogenation rate of the aromatic ring is 70% or more Styrene copolymer resin.   The hydrogenated styrene copolymer resin according to claim 1, wherein the weight average molecular weight in terms of standard polystyrene by gel permeation chromatography is from 800 to 3,000.   The hydrogenated styrenic 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 comprising the hydrogenated styrene copolymer resin according to any one of claims 1 to 3.