JPH0149423B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention is a highly elastic hydrogenated block copolymer composition that is highly flexible, has excellent high-temperature compression set, mechanical strength, and moldability, and can be used as a material for various molded products. It is related to. (Prior art) In recent years, thermoplastic elastomers, which are rubber-like soft materials that do not require a vulcanization process and have moldability similar to thermoplastic resins, have been used for automobile parts, home appliance parts, electric wire coatings, and medical applications. It is useful in the fields of parts, miscellaneous goods, footwear, etc. Among such thermoplastic elastomers, there are some elastomeric compositions using hydrogenated derivatives of vinyl aromatic compound-conjugated diene compound block copolymers (hereinafter abbreviated as hydrogenated block copolymers). Suggestions have been made. For example, JP-A-50-14742, JP-A-Sho.
No. 52-65551 and JP-A No. 58-206644 disclose an elastomeric composition in which a hydrogenated block copolymer is blended with a hydrocarbon oil and an olefinic polymer, and JP-A No. 59-131613 discloses In this method, an elastomeric composition prepared by blending a hydrogenated block copolymer with a hydrocarbon oil, an olefinic polymer, and an inorganic filler is partially crosslinked with an organic peroxide and a crosslinking aid, and the resulting elastomeric composition is Proposals have been made to improve rubber elasticity (compression set) at high temperatures. Furthermore, JP-A-54-88960, JP-A-59
-100159 and Japanese Patent Publication No. 57-56941 disclose hydrogenated block copolymer compositions containing a hydrogenated block copolymer and polyphenylene ether as essential components and consisting of a polyolefin resin and a polystyrene resin. There is. However, these proposals are aimed at improving the resin composition, and the resulting composition is a thermoplastic resin, and cannot be used as the thermoplastic elastomer mentioned above, but rather a rubber composition as an elastomeric composition. It had no elasticity. (Problems to be Solved by the Invention) Although the elastomeric composition of the hydrogenated block copolymer obtained by the above proposal has excellent rubber elasticity (compression set) at 70°C, the rubber elasticity at 100°C is 70°C. % or more, and does not reach the level of compression set at high temperatures conventionally required for vulcanized rubber applications, and although it has the recyclable moldability that is a characteristic of thermoplastic elastomers, it is inferior to rubber at high temperatures. The current situation is that the characteristics are still insufficient, and this has been taken for granted. (Means for Solving the Problems) The present invention has been made to solve the problems that are difficult to solve with the conventional elastomer molding materials described above, and in particular, the processability as a thermoplastic elastomer, recycling moldability, etc. This was done based on the desire for a molding material that could satisfy both properties of rubber elasticity and rubber elasticity at high temperatures (compression set at 100℃), which had not been achieved before. The inventors have found that this can be fully achieved by selecting an elastomeric composition, and have further discovered that it is a practically useful composition. That is, the present invention comprises (1) (a) a terminal polymer block A mainly composed of at least two vinyl aromatic compounds and an intermediate polymer block B mainly composed of at least one conjugated diene compound; Hydrogenated block copolymer a obtained by hydrogenating block copolymer 100 parts by weight (b) General formula (Here, R ₁ , R ₂ , R ₃ and R ₄ each represent a substituent selected from the group consisting of hydrogen, halogen, and hydrocarbon group, and may be the same or different.) Polyphenylene ether resin b, which is a homopolymer and/or copolymer, is composed of bonding units of tea/b=
90/10 to 30/70 (weight ratio) (c) Consists of 10 to 300 parts by weight of a softener for non-aromatic rubber, and has a compression set (100℃ x 22 hours).
A highly elastic hydrogenated block copolymer composition having a performance of 65% or less, comprising 5 to 100 parts by weight of the polyolefin resins (a), (b), (c) and (d), is compressed. Permanent deformation (100℃ x 22 hours)
Further embodiments of the highly elastic hydrogenated block copolymer composition having a performance of 65% or less include the above-mentioned (a), (b),
(c), (d) and (e) Contains 20 to 300 parts by weight of inorganic filler, and has a compression set (100℃ x 22 hours).
A highly elastic hydrogenated block copolymer composition having a performance of 65% or less, further comprising 20 to 300 parts by weight of the above-mentioned (a), (b), (c) and (e) inorganic filler, is compressed. Permanent deformation (100℃ x 22 hours)
The present invention provides highly elastic hydrogenated block copolymer compositions having a performance of 65% or less. The present invention will be described in detail below. In the present invention, compression set (100°C x 22 hours)
is the high temperature compression set as a rubber elastic body,
According to JIS-K6301, 100℃ x 22 hours, compression rate 25%
This value was measured under the following conditions. The hydrogenated block copolymer used as component (a) in the present invention consists of a terminal polymer block A mainly composed of at least two vinyl aromatic compounds and an intermediate polymer block A mainly composed of at least one conjugated diene compound. It is obtained by hydrogenating a block copolymer consisting of a combined block B, for example, A-B-
A, (A-B-) ₄ Si, A-B-A-B-A, (A-
B-) It is a hydrogenated vinyl aromatic compound-conjugated diene compound block copolymer having a structure such as Si-CH ₃ . This hydrogenated block copolymer contains 5 to 60% by weight, preferably 10 to 50% by weight of a vinyl aromatic compound, and furthermore, referring to the block structure, the terminal polymer block A mainly composed of a vinyl aromatic compound is , vinyl aromatic compound polymer block or vinyl aromatic compound 50
It has a structure of a copolymer block of a vinyl aromatic compound containing more than 70% by weight and preferably 70% by weight or more and a hydrogenated conjugated diene compound,
Furthermore, the intermediate polymer block B mainly composed of a hydrogenated conjugated diene compound contains more than 50% by weight of the hydrogenated conjugated diene compound polymer block or preferably 70% by weight of the hydrogenated conjugated diene compound. % or more of a hydrogenated conjugated diene compound and a vinyl aromatic compound. In addition, the terminal polymer block A mainly consists of these vinyl aromatic compounds and the intermediate polymer block B mainly consists of hydrogenated conjugated diene compounds. The distribution of the conjugated diene compound or vinyl aromatic compound is random, tapered (the monomer component increases or decreases along the molecular chain),
It may be partially block-shaped or in any combination thereof, and there may be two polymer blocks each consisting mainly of the vinyl aromatic compound and two polymer blocks mainly consisting of the hydrogenated conjugated diene compound. In the case where there are more than one, each polymer block may have the same structure or may have a different structure. As the vinyl aromatic compound constituting the hydrogenated block copolymer, one or more types can be selected from, for example, styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, etc.
Among them, styrene is preferred. Further, examples of the conjugated diene compound before hydrogenation constituting the hydrogenated conjugated diene compound include butadiene, isoprene, 3-pentadiene, 2,3-dimethyl-
One or more types are selected from 1,3-butadiene and the like, and among them, butadiene, isoprene, and a combination thereof are preferred. The microstructure of a polymer block mainly composed of a conjugated diene compound before hydrogenation can be arbitrarily selected; for example, in a polybutadiene block, the 1,2-microstructure is 20 to 50%.
%, preferably 25-45%. Further, the number average molecular weight of the hydrogenated block copolymer used in the present invention having the above structure is 5000 to 5000.
1000000, preferably 10000 to 800000, more preferably 30000 to 500000, and the molecular weight distribution [weight average molecular weight () and number average molecular weight ()
(Mw/Mn)] is 10 or less. Furthermore, the molecular structure of the hydrogenated block copolymer may be linear, branched, radial, or any combination thereof. These block copolymers may be produced by any method as long as they have the above structure. For example, a vinyl aromatic compound-conjugated diene compound block copolymer is synthesized in an inert solvent using a lithium catalyst or the like by the method described in Japanese Patent Publication No. 40-23798, and then, for example,
By the method described in Japanese Patent Publication No. 8704, Japanese Patent Publication No. 43-6636, or Japanese Patent Application Publication No. 59-133203,
The hydrogenated block copolymer used in the present invention can be synthesized by hydrogenation in an inert solvent in the presence of a hydrogenation catalyst. In this case, the number of aliphatic double bonds based on the conjugated diene compound of the vinyl aromatic compound-conjugated diene compound block copolymer is at least 80.
% can be hydrogenated to morphologically convert a polymer block mainly composed of a conjugated diene compound into an olefinic compound polymer block. In addition, hydrogenation of aromatic double bonds based on vinyl aromatic compounds copolymerized into polymer block A mainly composed of vinyl aromatic compounds and, if necessary, polymer block B mainly composed of conjugated diene compounds. Although there is no particular restriction on the hydrogenation rate, it is preferable that the hydrogenation rate is 20% or less. The amount of unhydrogenated aliphatic double bonds contained in the hydrogenated block copolymer can be easily determined using an infrared spectrophotometer, nuclear magnetic resonance apparatus, or the like. Next, the polyphenylene ether resin used as component (b) of the present invention is an essential component for improving the compression set (100°C x 22 hours) of the resulting composition to 65% or less, and its molecular The bonding unit of the chain is a general formula (Here, R ₁ , R ₂ , R ₃ and R ₄ each represent a substituent selected from the group consisting of hydrogen, halogen, and hydrocarbon group, and may be the same or different.) is a combination and or copolymer
The reduced viscosity measured at 30° C. in a 0.5 g/dl chloroform solution is in the range of 0.15 to 0.70, more preferably in the range of 0.20 to 0.60. As this polyphenylene ether resin, known ones can be used. A specific example is poly(2,6-dimethyl-
1,4-phenylene ether, poly(2-methyl-6ethyl-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene)
Ether, poly(2-methyl-6-phenyl-
1,4-phenylene)ether, poly(2,6-
Dichloro-1,4-phenylene) ether, etc., and 2,6-dimethylphenol and other phenols (e.g. 2,3,6-trimethylphenol and 2-methyl-6-butylphenol)
Also included are polyphenylene ether copolymers such as copolymers with. Among them, poly(2,6-dimethyl-1,4-phenylene) ether, 2,6
A copolymer of -dimethylphenol and 2,3,6-trimethylphenol is preferred, and poly(2,6-dimethyl-1,4-phenylene) ether is more preferred. Poly(2,6-dimethyl-1,4-
reduced viscosity (0.5 g/dl,
(chloroform solution, measured at 30°C) preferably ranges from 0.15 to 0.70, more preferably from 0.30 to 0.70.
It is in the range of 0.60. The amount of component (b) to be blended can be suitably selected so that the weight ratio of component (a) hydrogenated block copolymer/component (b) polyphenylene ether is in the range of 90/10 to 30/70. . If the weight ratio is less than 30/70, the hardness of the resulting elastomeric composition will be too high, resulting in a loss of flexibility and resulting in a resinous composition, which will not only result in a product with a rubbery feel, but also be difficult to handle at high temperatures. The rubber elasticity [compression set (100°C x 22 hours)] exceeds 65%, which is unfavorable. Furthermore, in a formulation where the weight ratio exceeds 90/10, no improvement in rubber elasticity (compression set) at high temperatures is observed as an effect of adding polyphenylene ether, which is not preferred). The rubber softener used as component (c) in the present invention is an essential component for making the resulting composition into a flexible rubber-like composition, and is a non-aromatic mineral oil, liquid or low molecular weight synthetic rubber softener. Softeners are suitable. Among these, mineral oil-based rubber softeners, called process oils or extender oils, which are generally used to soften, increase volume, and improve processability of rubber, are mixtures of aromatic rings, naphthenic rings, and paraffin chains. Those in which the number of carbon atoms in the paraffin chain accounts for 50% or more of the total carbons are called paraffin series, and the number of carbon atoms in the naphthene ring is 30 to 45%.
Those are naphthenic, and the number of aromatic carbons is 30%.
Those with a larger amount are considered aromatic. Components of the invention
The mineral oil-based rubber softener used as (c) is preferably a naphthene-based or paraffin-based one in the above category, and an aromatic one with an aromatic carbon number of 30% or more is the same as component (a). The composition is unfavorable in terms of dispersibility and solubility. The properties of these non-aromatic rubber softeners include a kinematic viscosity of 20 to 500 cst at 37.8°C, a pour point of -10 to -15°C, and a flash point of 170 to 300°C. As the synthetic softener, polybutene, low molecular weight polybutadiene, etc. can be used, but the above-mentioned mineral oil-based softeners for rubber give better results. The amount of the softener (component (c)) is 10 to 300 parts by weight, preferably 20 parts by weight, per 100 parts by weight of component (a).
~250 parts by weight. If the amount exceeds 300 parts by weight, the softener tends to bleed out, which may result in stickiness in the final product and also deteriorate mechanical properties. If the amount is less than 10 parts by weight, the resulting composition becomes close to a resin composition, increases in hardness, loses flexibility, and is also unfavorable from an economic point of view. Next, the polyolefin resin used as component (d) of the present invention is effective in improving the processability and/or heat resistance of the resulting composition, such as polyethylene, isotactic polypropylene,
Copolymers of propylene and small amounts of other α-olefins, such as propylene-ethylene copolymers, propylene-1-hexene copolymers, propylene-4
-Methyl-1-pentene copolymer and poly-4-
Examples include methyl-1-pentene and polybutene-1. MFR when using polypropylene as the olefin resin used
(ASTM-D-1238-L conditions, 230℃) is 0.1 to 50
g/10 minutes, particularly preferably in the range of 0.5 to 30 g/10 minutes. The blending amount of component (d) is 5 parts per 100 parts by weight of component (a).
-100 parts by weight, preferably 10-70 parts by weight. If the amount exceeds 100 parts by weight, the hardness of the resulting elastomeric composition becomes too high, resulting in a loss of flexibility and a product with a rubbery feel. (distortion) becomes extremely bad, which is undesirable. Furthermore, when the amount is less than 5 parts by weight, the polyolefin resin exhibits the same processability as the composition of the present invention to which it is not added. Furthermore, as an example of an embodiment of the present invention, the inorganic filler used as component (e) not only has the benefit of reducing product cost as an extender, but also has the advantage of actively improving quality (compression set, etc.). Add effect. Examples of inorganic fillers include calcium carbonate,
Carbon black, talc, magnesium hydroxide, mica, clay, barium sulfate, natural silicic acid, synthetic silicic acid (white carbon), titanium oxide, etc. are available, and as carbon black, channel black, furnace black, etc. can be used. Among these inorganic fillers, talc, calcium carbonate and furnace black are economically advantageous and preferred. It is also possible to add a conductive filler to impart conductivity; for example, conductive carbon such as ketchen black may be used. The blending amount of the inorganic filler is 20 to 300 parts by weight per 100 parts by weight of the hydrogenated block copolymer of component (a),
Preferably it is 30 to 250 parts by weight. When the amount exceeds 300 parts by weight, the mechanical strength of the composition decreases significantly, and the hardness increases and flexibility is lost.
It becomes impossible to obtain a product with a rubbery feel. Furthermore, when the amount is less than 20 parts by weight, the composition exhibits the same performance as the composition of the present invention obtained when the inorganic filler is not added. If necessary, flame retardants, glass fibers, carbon fibers, antioxidants, heat stabilizers, ultraviolet absorbers, hindered amine light stabilizers, and colorants can be added to the highly elastic elastomeric composition of the present invention. As a method for compounding the highly elastic elastomeric composition of the present invention, methods used in the production of ordinary resin compositions or rubber compositions can be adopted, such as a single screw extruder, a twin screw extruder, a Banbury mixer, Composite composition can be performed using a melt kneader such as a heating roll, Brabender, or various kneaders. At this time, there is no restriction on the order of addition of each component,
For example, all components are premixed in a mixer such as a Henschel mixer or a blender, premixed in the above-mentioned kneading machine, and melted and composited in the abovementioned kneading machine, or arbitrary components are premixed and melted and composited in a master batch.
Furthermore, an addition method such as adding the remaining components and melting and compounding them can be adopted. The composite composition of the present invention can be molded using a commonly used thermoplastic resin molding machine, and various molding methods such as injection molding, extrusion molding, blow molding, and calendar molding can be applied. It is possible. (Effects of the Invention) The composition obtained by the present invention has excellent flexibility, heat resistance, mechanical strength, and rubber elasticity at high temperatures, as well as excellent coating properties and electrical insulation properties during molding processing. Its fields of use include various electric wire coatings (insulation, sheathing), making use of its high rubber elasticity,
It can be suitably molded and used for home appliance parts, automobile parts, and various industrial parts. Specific applications include various gaskets, flexible tubes, hose coverings, weather strips, flexible bumpers, side bumpers, moldings, filler panels,
Includes life housing, wire cable covering, air intake hose, cushion panel, etc. (Examples) The present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. In addition, in these Examples and Comparative Examples,
The test methods used for various evaluations are as follows. (1) Hardness [-] JIS-K6301, A type (2) Tensile strength [Kg/cm ² ] and tensile elongation [%] JIS-K-6301, test using a 2 mm thick in-die extension sheet as a sample. The piece is size 3. (3) Compression set [%] JIS-K-6301, 70℃ and 100℃ 22 hours, 25
% deformation. The ingredients blended are as follows. (1) <Component (a-1)> Polystyrene-hydrogenated polybutadiene-polystyrene structure, bound styrene content 27%, number average molecular weight 157000, molecular weight distribution
1.07, a hydrogenated block copolymer with a 1,2 bond content of polybutadiene before hydrogenation of 34% and a hydrogenation rate of 98% was synthesized using a Ti-based hydrogenation catalyst described in JP-A-59-133203, It was designated as component (a-1). <Component (a-2)> (Polystyrene - hydrogenated polybutadiene) Has a structure of ₄ Si, with a bound styrene content of 36%,
A hydrogenated block copolymer with a number average molecular weight of 379,000, a molecular weight distribution of 1.35, a 1,2 bond content of polybutadiene before hydrogenation of 27%, and a hydrogenation rate of 99% was produced in JP-A-59-
Synthesized using the Ti-based hydrogenation catalyst described in No. 133203,
It was designated as component (a-2). <Ingredient (a-3)> KRATON-G1651 manufactured by Ciel Chemical Co., Ltd. <Ingredient (a-4)> KRATON-G1650 manufactured by Ciel Chemical Company (2) Ingredient (b) Diana Process Oil PW manufactured by Idemitsu Norisan Co., Ltd.
380 [paraffinic, kinematic viscosity; 381.6cst (40℃),
30.1cst (10℃), average molecular weight 746, ring analysis; C _N =
27%, C _P = 73%] (3) Component (c) Polypropylene resin manufactured by Asahi Kasei Co., Ltd., M-1300
[MFR (230℃) 4g/10 minutes] (4) Component (d) Calcium carbonate manufactured by Shiraishi Calcium Co., Ltd., Whitein SB (5) Component (e) Poly(2,6-dimethyl-) as polyphenylene ether resin 1,4-phenylene) ether (reduced viscosity: 0.37, 0.57) was synthesized. Examples 1 to 6 Hydrogenated block copolymers (a-1) to (a
-3) and polyphenylene ether with a reduced viscosity of 0.57. After mixing each component shown in Table-1 in a Henschel mixer, melt-knead at 250℃ in a 50 mm diameter twin screw extruder. Pellets of thermoplastic elastomer were obtained. This was evaluated as an injection molded product, and the results are listed in Table 1. From these results, it is clear that the elastomeric composition of the present invention has a compression set of 50% or less at 100°C and is excellent in rubber elasticity at high temperatures. Furthermore, these compositions also had excellent moldability.

[Table] Comparative Examples 1 to 7 Hydrogenated block copolymers (a-1) to (a
-3) and a polyphenylene ether with a reduced viscosity of 0.57, the components shown in Table 2 were kneaded in the same manner as in Examples 1 to 6, and further molded and evaluated. The results are listed in Table 2. From this result, it can be seen that compositions outside the scope of the present invention have a
Although it has excellent compression set at 100°C, it has become clear that the compression set at 100°C is extremely poor and its rubber elasticity at high temperatures is poor. Additionally, KRATON is a commercially available elastomeric composition of hydrogenated block copolymers.
- Although the composition of G2705, G-7720, and G-7820 (all manufactured by Ciel Chemical) is unknown, it has been revealed that the compression set at 100°C is poor and the rubber elasticity at high temperatures is poor.

【table】

[Table] Examples 7 to 9 Comparative Examples 8 to 10 Using (a-4) as the hydrogenated block copolymer and having a reduced viscosity of 0.37 as the polyphenylene ether, each component shown in Table 3 was added. The mixture was kneaded in the same manner as in Examples 1 to 6, and then molded and evaluated. The results are listed in Table 3. From this result, even though the hydrogenated block copolymer compositions (Comparative Examples 8 to 10) using (a-4) had extremely deteriorated compression set at 70°C,
The hydrogenated block copolymer composition of the present invention to which polyphenylene ether is added has greatly improved compression set at 70°C and compression set at 100°C, and has improved rubber elasticity at high temperatures. It became clear.

[Table] Example 10 (a-1) was used as the hydrogenated block copolymer, 2,
2,6 containing 5% 3,6-trimethylphenol
-A test piece was made with the same formulation as in Example 4, except that dimethylphenol was polymerized to obtain a 2,6-dimethylphenol/2,3,6-trimethylphenol copolymer (reduced viscosity 0.51).
When evaluated, the hardness was 75, the pore tensile strength was 180Kg/cm ² ,
Elongation 390%, compression set (100℃×22HRS) 38%
A highly elastic hydrogenated block copolymer composition having the following properties was obtained. Example 11 Polystyrene-poly(styrene/butadiene=
10/90% by weight) - poly(styrene/butadiene =
10/90% by weight) - poly(styrene/butadiene =
10/90% by weight) - has a polystyrene structure, and has three tapered blocks in which styrene gradually increases in the poly(styrene/butadiene = 10/90% by weight) part, with a total bound styrene content of 37% and a block styrene content of 30%. %, number average molecular weight 156000, molecular weight distribution 1.05,
A block copolymer with a 1,2 bond content of 35% was synthesized, and was further described in JP-A-59-133203.
A hydrogenation reaction is carried out using a Ti-based hydrogenation catalyst, and the hydrogenation rate is
A 99% hydrogenated block copolymer was obtained. Except for using this hydrogenated block copolymer, it was blended with the same composition as in Example 5, kneaded and injection molded in the same manner, and evaluated. The hardness was 74, and the tensile strength was 100 kg/
^cm2 , elongation 400%, compression set (100℃×22HRS)
A highly elastic hydrogenated block copolymer composition with properties of 42% was obtained.

Claims (1)

[Scope of Claims] 1 (a) A block combination consisting of a terminal polymer block A mainly composed of at least two vinyl aromatic compounds and an intermediate polymer block B mainly composed of at least one conjugated diene compound. Hydrogenated block copolymer obtained by hydrogenating a polymer
a100 parts by weight (b) General formula (Here, R ₁ , R ₂ , R ₃ and R ₄ each represent a substituent selected from the group consisting of hydrogen, halogen, and hydrocarbon group, and may be the same or different.) Polyphenylene ether resin b, which is a homopolymer and/or copolymer and has a reduced viscosity in the range of 0.15 to 0.70 measured in a 0.5 g/dl chloroform solution at 30°C, is a/b for the above a/b. =90/10~30/70
(Weight ratio) (c) A highly elastic hydrogenated block copolymer consisting of 10 to 300 parts by weight of a non-aromatic rubber softener and having a compression set (100°C x 22 hours) of 65% or less. Composition. 2 (a) Hydrogenating a block copolymer consisting of a terminal polymer block A mainly composed of at least two vinyl aromatic compounds and an intermediate polymer block B mainly composed of at least one conjugated diene compound. Hydrogenated block copolymer obtained by
a100 parts by weight (b) General formula (Here, R ₁ , R ₂ , R ₃ and R ₄ each represent a substituent selected from the group consisting of hydrogen, halogen, and hydrocarbon group, and may be the same or different.) Polyphenylene ether resin b, which is a homopolymer and/or copolymer, has a reduced viscosity in the range of 0.15 to 0.70 measured in a 0.5 g/dl chloroform solution at 30°C, and has a/ b=90/10~30/
70 (weight ratio) (c) 10 to 300 parts by weight of a non-aromatic rubber softener (d) 5 to 100 parts by weight of a polyolefin resin, with a compression set (100°C x 22 hours) of 65% or less A highly elastic hydrogenated block copolymer composition with excellent performance.