JP3393818B2 - Thermoplastic elastomer composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a conventional rigid PVC.
In the field where two-color simultaneous molding of (polyvinyl chloride) and soft PVC was used (for example, door packing), when a material other than PVC is being used due to environmental issues, it is usually used as a substitute for rigid PVC. ABS used
The present invention relates to a soft PVC substitute elastomer composition that can be melt-bonded with.

[0002]

2. Description of the Related Art Conventionally, two-color simultaneous molding (extrusion molding, hard PVC / soft PVC) for various applications in the field of building materials and home appliances.
Injection molding) was used. However, due to recent environmental issues, the use of PVC has been shunned, and ABS resin is often used on the hard side as an alternative material, but there is no suitable soft material that melt-bonds with ABS, and it adheres to the interface. Molded products were often produced through more complicated processes such as the use of agents. In this case, the total cost becomes considerably high, and PV can only be used in limited fields.
The current situation is that replacement from C has not progressed.

[0003]

The present invention solves the above problems of the prior art and makes it possible to obtain a two-color molded product with ABS resin having sufficient adhesive strength in the same processing step as PVC. To provide a novel thermoplastic elastomer composition.

[0004]

As a result of various studies, the inventors of the present invention have found that the styrene elastomer known as a hydrogenated block copolymer has a number average molecular weight of 70 in particular.
000 or more as a main component, in the presence of a styrenic elastomer modified with a polar group, thermoplastic polyurethane or a saturated polyester resin is added and alloyed to exhibit good melt adhesion with ABS, and further with propylene. Based on the compounding design concept of maintaining heat resistance and moldability by adding a copolymer with an α-olefin having 2 to 8 carbon atoms and alloying it, good adhesion is achieved by two-color simultaneous extrusion molding with ABS. It was found that a molded product having the above can be obtained, and the present invention has been completed.

That is, the present invention relates to the following components a, b,
It is a thermoplastic elastomer composition comprising c, d or components a, b, c, e. (A) by hydrogenating a block copolymer comprising at least two terminal polymer blocks A mainly containing vinyl aromatic compounds and intermediate polymer blocks B mainly containing at least one conjugated diene compound A hydrogenated block copolymer having a number average molecular weight of 70,000 or more 5
60% by weight (b) Hydrogen is used as a block copolymer composed of at least two terminal polymer blocks A mainly composed of vinyl aromatic compounds and at least one intermediate polymer block B mainly composed of conjugated diene compounds. The hydrogenated block copolymer obtained by addition is modified with a polar group and has an acid value of 1 to 30 mg.
(CH ₃ ONa) / g 1 to 20% by weight (c) Copolymer of propylene and α-olefin having 2 to 8 carbon atoms and having a heat distortion temperature of 90 ° C. or higher 5 to 60% by weight (d ) Thermoplastic polyurethane 20 to 80% by weight (e) Saturated polyester resin 20 to 80% by weight

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The hydrogenated block copolymer used in the present invention comprises 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. Is obtained by hydrogenating the following block copolymer, and is a hydrogenated vinyl aromatic compound-conjugated diene compound block copolymer having a structure represented by the following general formula. A- (BA) n (1 ≦ n ≦ 5) This hydrogenated block copolymer has a hardness of 99 or less, preferably 90 or less, in order to obtain a hydrogenated block copolymer elastomer composition. Therefore, the vinyl aromatic compound is contained in an amount of 5 to 50% by weight, preferably 10 to 40% by weight. Further, regarding the block structure, the terminal polymer block A mainly composed of a vinyl aromatic compound is a vinyl aromatic compound polymer block or a vinyl aromatic compound containing more than 50% by weight and preferably 70% by weight or more of a vinyl aromatic compound. The intermediate polymer block B having a structure of a copolymer block of a group compound and a hydrogenated conjugated diene compound, the intermediate polymer block B mainly containing the hydrogenated conjugated diene compound is a hydrogenated conjugated diene compound It has a structure of a united block or a copolymer block of a hydrogenated conjugated diene compound and a vinyl aromatic compound containing more than 50% by weight, preferably 70% by weight or more of a hydrogenated conjugated diene compound. . When there are two or more polymer blocks mainly containing a vinyl aromatic compound and polymer blocks mainly containing a hydrogenated conjugated diene compound, each polymer block may have the same structure or different. It may be a structure.

As the vinyl aromatic compound constituting the hydrogenated block copolymer, for example, one kind or two or more kinds can be selected from styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene and the like. Of these, styrene is preferable. As the conjugated diene compound before hydrogenation constituting the hydrogenated conjugated diene compound, for example, one kind or two or more kinds are selected from butadiene, isoprene, 2.3-dimethyl-1.3-butadiene and the like. Among them, butadiene, isoprene and combinations thereof are preferable. Further, the molecular structure of the hydrogenated block copolymer may be linear, branched, radial or any combination thereof. The number average molecular weight (Mn) of the hydrogenated block copolymer of the component a used in the present invention is 70.
000 or more, preferably 90,000 to 200,000, and the molecular weight distribution Mw / Mn is 10 or less (Mw: weight average molecular weight), preferably 5 or less, more preferably 2 or less. When the number average molecular weight is less than 70,000,
It cannot give sufficient strength. Molecular weight distribution is 1
If it exceeds 0, the strength decreases. The blending amount of the component a is 5 to 60% by weight, preferably 20 to 50% by weight. When the content of the component a is less than 5% by weight, sufficient strength and flexibility cannot be imparted, and when it exceeds 60% by weight, the fluidity is remarkably reduced and a molded product having a good appearance after molding is obtained. Can't get Further, since the hydrogenated block copolymer of the component a has a large number average molecular weight, an oil-extended product of paraffinic oil can be appropriately used for improving workability. Further, the hydrogenated block copolymer of the component a has a spring hardness in applications requiring flexibility.
It is preferable that (JIS K6301) is 99 or less.

The polar group modification product of the hydrogenated block copolymer used as the component b of the present invention improves the compatibility between the resulting component a and component d, or component a and component e,
As a result, it contributes to the improvement of processability, appearance and mechanical properties of the composition. A polymer obtained by modifying the hydrogenated block copolymer of the component a with maleic anhydride, an epoxy ring-containing group, or the like corresponds to this. Among them, the acid value is 1 to 30 mg (CH ₃ ON
Those of a) / g are preferred. Acid value is 1 mg (CH ₃ ONa)
If it is less than / g, a sufficient compatibility improving effect cannot be obtained,
If it exceeds g (CH ₃ ONa) / g, the strength is deteriorated and the molded appearance is deteriorated. The blending amount of the component b is 1 to 20% by weight, preferably 2 to 10% by weight. If it is less than 1% by weight, the effect of improving the compatibility cannot be obtained, and if it exceeds 20% by weight, the strength is lowered and the appearance is deteriorated.

The copolymer of propylene used as the component c of the present invention and the α-olefin having 2 to 8 carbon atoms is, for example, a random and / or block copolymer of propylene and a small amount of other α-olefin, specifically, Specifically, propylene-ethylene copolymer, propylene-1-hexene copolymer, propylene-4-methyl-1-pentene copolymer, and poly-4-methyl-1-pentene, polybutene-
1, ethylene-propylene block copolymers are preferred, and the ethylene content is 2
It is preferably about 30% by weight. Further high temperature aging test,
A nucleating agent is preferably added in order to suppress changes in physical properties in a weather resistance test. This propylene and carbon number 2
The melt flow rate (ASTM-D-1238L condition, 230 ° C.) of the copolymer with the α-olefin of 0.1 to 60 g / 1
Those having a range of 0 min, particularly 0.5 to 50 g / 10 min can be preferably used. Melt flow rate is 0.1 g /
If it is less than 10 min, the fluidity at the time of molding deteriorates, and 60 g
If it is greater than / 10 min, the heat resistance will decrease, which is not preferable. In addition, here the heat distortion temperature (ASTM-D-648, 4.6 kgf
The reason why / cm ² ) is limited to 90 ° C. or higher is that if it is lower than 90 ° C., there is no effect in improving heat resistance. The content of the component c is 5 to 60% by weight, preferably 10 to 5%.
It is 0% by weight. If the content of the component c is less than 5% by weight, sufficient heat resistance cannot be imparted, and if it exceeds 60% by weight, the impact resistance at low temperature is significantly reduced.

The thermoplastic polyurethane of the component d used in the present invention improves the heat fusion strength with ABS. Thermoplastic polyurethanes are usually made by the polyaddition reaction of diisocyanates and polyols. Examples of diisocyanates include tolylene diisocyanate and diphenylmethane-
4,4'-diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, etc.
As the polyol, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, poly (1,4
-Butylene adipate, poly (1,6-hexylene adipate), poly-ε-caprolactone, poly (hexamethylene carbonate), poly (oxytetramethylene) glycol, etc., and those made by combining a plurality of these But good. Thermoplastic polyurethanes are roughly classified into ester polyurethanes and ether polyurethanes depending on the type of polyol used, and the thermoplastic polyurethane used in the present invention may be either of these. 20-80% by weight as the amount of component d
And preferably 25 to 60% by weight. If it is less than 20% by weight, a sufficient heat fusion strength to desired ABS cannot be obtained, and if it exceeds 80% by weight, the strength is lowered and the cost is increased.

The saturated polyester resin of the component e used in the present invention improves the heat fusion strength with ABS, like the component d. The saturated polyester resin is usually obtained by polycondensation of a dibasic acid and a dihydric alcohol. Examples of the saturated polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyarylate, poly-p-oxybenzoyl and the like. In the present invention, those in which the crystalline state of these saturated polyester resins is controlled by the third component, and elastomers containing these as the constituent components may be used. The compounding amount of the e component is 20 to 80% by weight, preferably 25 to 60% by weight. If it is less than 20% by weight, the desired heat fusion strength to ABS cannot be obtained, and if it exceeds 80% by weight, the strength is lowered and the cost is increased.

In addition to the above components (a) to (e), the composition of the present invention may further contain a cheap resin such as paraffin oil, an inorganic filler and a polystyrene resin, if necessary. Is also possible. These not only have the benefit of reducing the product cost as an extender, but also have a positive effect on quality improvement (inorganic filler: heat-resistant shape retention, flame retardancy imparting polystyrene resin: processability improvement, etc.). There is also an advantage. As the polystyrene resin that can be used for this purpose, those obtained by a radical polymerization method or an ionic polymerization method can be preferably used, and the number average molecular weight thereof is 5,000 to 5,000.
It can be selected from the range of 500,000, preferably 10,000 to 200,000, and the molecular weight distribution Mw / Mn is preferably 5 or less. Examples of the inorganic filler include calcium carbonate, carbon black, talc, magnesium hydroxide, mica, barium sulfate, natural silicic acid, synthetic silicic acid (white carbon), titanium oxide and the like, and carbon black includes channel black, Furnace black etc. can be used. Among these inorganic fillers, talc and calcium carbonate are economically advantageous and preferable. Further, if necessary, a nucleating agent, an external lubricant, an internal lubricant, an ultraviolet absorber, a hindered amine light stabilizer, a hindered phenol antioxidant, a colorant and the like may be added.

The method for producing the composition of the present invention includes:
A general method used for producing a usual resin composition or rubber composition can be adopted. Basically, it is a mechanical melt-kneading method, and a single-screw extruder, a twin-screw extruder, a Banbury mixer, various kneaders, brabenders, rolls and the like are used for these. At this time, the addition order of each component is not limited, for example, all components are premixed by a mixer such as a Henschel mixer and a blender and melt-kneaded by the above kneader, or any components are premixed to form a masterbatch. It is possible to employ an addition method in which the components are melt-kneaded, and then the remaining components are added and melt-kneaded. Further, at this time, the temperature for melt kneading is 1
It can be suitably selected from 80 ° C to 300 ° C.

[0014]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The components blended in the examples and comparative examples are as follows. <Component a> Tuftec H1272 manufactured by Asahi Kasei Kogyo Co., Ltd .: having a structure of polystyrene-hydrogenated polybutadiene-polystyrene, a bound styrene content of 35% by weight, and a number average molecular weight of about 120,000 (paraffin-based oil (Diana Process Oil PW manufactured by Idemitsu Kosan Co., Ltd. -380 [paraffin-based process oil, kinematic viscosity: 381.6 cst (40 ° C.),
30.1 (100 ° C), average molecular weight 746, ring analysis value:
CA = 0%, CN = 27%, CP = 73%]) 35% by weight
Oil product). <Component b> manufactured by Asahi Kasei Tuftec M1913: polystyrene - hydrogenated polybutadiene - has the structure polystyrene, acid value with a polar group introduced in bound styrene content 30% by weight _{10mg (CH 3 ONa) / g} . <Component c> Asahi Kasei Corporation ethylene-propylene block copolymer: Asahi Polypro M7646: Melt flow rate 15 dg / min (ASTM D1238), heat distortion temperature 120 ° C (ASTM D648 (4.6 Kgf / cm ² ) <Component d> Pandex T50 manufactured by Dainippon Ink and Chemicals
00V: Ester type polyurethane (diphenylmethane-
4,4'-diisocyanate / polyol). <Component e> Eastapak made by Eastman Chemical
PET9921: Polyester with controlled crystalline state
1,4-cyclohexanedimethanol copolymer.

In Examples 1 and 2 and Comparative Examples 1 to 12, after thoroughly dry blending the compounds having the blending ratios shown in the table, the resin temperature was 180 to 270 ° C. using a biaxial kneader. It was melt-kneaded and extruded into pellets. The following evaluation was performed using this pellet. (1) Appearance: 0.5 mm from this pellet with an extruder.
It was formed into a tape shape using a die having a thickness of 20 mm and visually observed for spots, rough skin, and the like. (2) ABS bond strength: Using an injection molding machine, melt and inject this pellet into a mold into which an ABS resin plate has been inserted, and
A layer molded product was obtained. This molded product was cut into a width of 20 mm to give a test piece, and a 180 ° peel test was conducted with a universal tensile tester (unit: kgf / 20 mm). (3) Tensile strength: This pellet is rolled into a sheet shape, a 2 mm thick sheet is formed with a press, a dumbbell is punched from this sheet, and a tensile test is performed with a universal tensile tester according to JIS K 6301. (Unit: MPa)

The results of Example 1 and Comparative Examples 1 to 6 of the system using the thermoplastic polyurethane are shown in Table 1, and the results of Example 2 of the system using the saturated polyester resin and Comparative Examples 7 to 12 are shown in Table 2. Indicated. From these results, it can be seen that the composition obtained in the present invention is excellent in appearance, strength, and ABS heat fusion property.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

According to the composition of the present invention, conventional hard PV
It is a good material to replace soft PVC when hard PVC is replaced by ABS resin due to the recent trend of PVC removal in applications where a two-color molded product with a combination of C / soft PVC was used. It is possible to provide a molded product that exhibits ABS heat fusion properties and is excellent in both appearance and strength.

Claims (2)

(57) [Claims] 1. A thermoplastic elastomer composition comprising the following (a) to (d): (A) by hydrogenating a block copolymer comprising at least two terminal polymer blocks A mainly containing vinyl aromatic compounds and intermediate polymer blocks B mainly containing at least one conjugated diene compound A hydrogenated block copolymer having a number average molecular weight of 70,000 or more 5
60% by weight (b) Hydrogen is used as a block copolymer composed of at least two terminal polymer blocks A mainly composed of vinyl aromatic compounds and at least one intermediate polymer block B mainly composed of conjugated diene compounds. The hydrogenated block copolymer obtained by addition is modified with a polar group and has an acid value of 1 to 30 mg.
(CH ₃ ONa) / g 1 to 20% by weight (c) Copolymer of propylene and α-olefin having 2 to 8 carbon atoms and having a heat distortion temperature of 90 ° C. or higher 5 to 60% by weight (d ) Thermoplastic polyurethane 20 to 80% by weight 2. A thermoplastic elastomer composition comprising the following (a) to (e): (A) by hydrogenating a block copolymer comprising at least two terminal polymer blocks A mainly containing vinyl aromatic compounds and intermediate polymer blocks B mainly containing at least one conjugated diene compound A hydrogenated block copolymer having a number average molecular weight of 70,000 or more 5
60% by weight (b) Hydrogen is used as a block copolymer composed of at least two terminal polymer blocks A mainly composed of vinyl aromatic compounds and at least one intermediate polymer block B mainly composed of conjugated diene compounds. The hydrogenated block copolymer obtained by addition is modified with a polar group and has an acid value of 1 to 30 mg.
(CH ₃ ONa) / g 1 to 20% by weight (c) Copolymer of propylene and α-olefin having 2 to 8 carbon atoms and having a heat distortion temperature of 90 ° C. or higher 5 to 60% by weight (e ) Saturated polyester resin 20-80% by weight