JPH0670164B2 - Elastomer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention can be used as an elastomer material for various molded parts in a wide range of fields such as food field, medical field, electric / electronic field, automobile field, leisure / sports field. Also, it can be used in various industrial fields such as primer and sealant for paint, packing, protective material for edge part, inner lining material for hose, etc. Flexible containing mainly hydrogenated block copolymer and polyurethane elastomer The present invention relates to an elastomer composition having excellent properties, rubber elasticity, oil resistance, abrasion resistance, mechanical strength, paintability, adhesiveness, and moldability.

(Prior Art) An elastomer composition containing a hydrogenated block copolymer as a main component has excellent flexibility, rubber elasticity, electrical characteristics,
Taking advantage of hygiene and molding processability, it has recently attracted attention as a soft material for flexible molded parts in the food field, medical field, electric / electronic field, automobile field and various industrial fields.

Information regarding the elastomer composition containing the hydrogenated block copolymer, which is the soft material, can be found in, for example, JP-A-50-14742.
JP, JP 50-114446 JP, JP 52-53957 JP, JP 58-206644 JP, JP 60-86154 JP,
JP-A-61-42554, JP-A-61-152759, JP-A-61-155446, JP-A-61-243852, JP-A-62
It can be easily understood from the proposals of JP-A-15253 and JP-A-62-81443. As seen in these proposals, the elastomer composition containing the hydrogenated block copolymer is composed of the hydrogenated block copolymer, the polyolefin and the softening agent, but due to the blended polyolefin, As the hardness of the composition to be used becomes higher and harder,
Usually, an oil is added as a softening agent to soften (decrease the hardness).

(Problems to be Solved by the Invention) As described above, the elastomer composition containing the hydrogenated block copolymer described above contains the polyolefin to be blended for adjusting the hardness of the obtained elastomer composition and the oil as the softening agent. At present, the hardness is adjusted appropriately to obtain an arbitrary hardness. Due to this, when a large amount of a softening agent is added, there is a drawback that the oil bleeds.

Further, the elastomer composition containing the hydrogenated block copolymer described above, due to the hydrogenated block copolymer, has the disadvantage of poor oil resistance, to make a composition substantially excellent in oil resistance. In the present situation, the amount of polyolefin to be blended must be increased, and therefore only a hard elastomer composition having a high hardness can be obtained.

It is an object of the present invention to find and provide an elastomer composition having an excellent balance of hardness and oil resistance, which was difficult with the elastomer composition containing the hydrogenated block copolymer of the prior art described above.

(Means for Solving Problems) In view of such a situation as described above, the present invention has been earnestly studied to find an elastomer composition containing a hydrogenated block copolymer, which is soft and excellent in oil resistance. As a result of stacking, usually, a composition composed of a hydrogenated block copolymer and a polyurethane elastomer having poor compatibility is blended with a polymer having a specific structure to remarkably improve the compatibility of both of them. The present invention was found to provide an elastomer composition that is soft and has excellent oil resistance, and has reached the present invention.

That is, the present invention comprises (a) a hydrogenated block copolymer (b) a polyurethane elastomer, and (c) an epoxy group-containing polymer (0.5) based on 100 parts by weight of the total amount of (a) + (b). An elastomer composition comprising about 30 to 30 parts by weight is provided.

Hereinafter, the present invention will be described in detail.

The hydrogenated block copolymer used as the component (a) of the present invention is a block copolymer composed of a polymer block segment containing a vinyl aromatic compound as a main component and a polymer block segment containing a conjugated diene compound as a main component. It is a hydrogenated block copolymer obtained by hydrogenation. The structural characteristics of this hydrogenated block copolymer are described in JP-A-61-340.
One type or two or more types can be used in combination as long as the requirements described in detail in Japanese Patent Publication No. 49 are satisfied.

Specific examples of this hydrogenated block copolymer include “Tuftec” from Asahi Kasei Kogyo Co., Ltd., Shell Chemical Com.
The one sold by Pany under the name "Clayton G" may be used, but is not limited thereto.

Next, the polyurethane elastomer used as the component (b) of the present invention is a polymer having a urethane group (-NHCOO-) in the molecular chain by the reaction of polyisocyanate and polyol (long-chain polyol, short-chain polyol),
As long as the Shore D hardness (JIS K7311) is 75 or less, one type or two or more types from commercially available ones can be used together.

Specific examples of this polyurethane elastomer include, for example, "Paraprene" from Nippon Polyurethane Co., Ltd., "Pandex" from Dainippon Ink and Chemicals, Inc., "Miractran" from Nippon Miractolan Co., Ltd., and MD Chemicals Co., Ltd. "Peresen", Takeda Birdish Urethane Industry Co., Ltd. "Elastoran" or "Takelac",
The products sold under the names “Resamine” by Dainichiseika Co., Ltd. and “Desmopan” by Sumitomo Bayer Urethane Co., Ltd. may be used, but the present invention is not limited thereto.

The mixing ratio of these components (a) and (b) is (a) /
(B) = 5-95% by weight / 95-5% by weight, more preferably 1
A proportion of 0 to 80% by weight / 90 to 20% by weight, and a ratio of 30 to 70% by weight / 70 to 30% by weight is necessary to obtain an elastomer composition having more preferable oil resistance and rubber elasticity.

The epoxy group-containing polymer used as the component (c) of the present invention is the hydrogenated block copolymer of the component (a) and (b).
A compatibilizer that improves the compatibility with the component polyurethane elastomer, specifically, for example, a polyolefin resin, a polyolefin elastomer, a styrene resin, an epoxy group-containing polymer corresponding to a styrene elastomer, These production methods are easily obtained by copolymerizing or graft-polymerizing an epoxy group-containing unsaturated compound. The amount of epoxy in the epoxy group-containing polymer needs to be 0.2 to 15% by weight, preferably 0.5 to 10% by weight, and more preferably 1 to 7% by weight in terms of epoxy group-containing unsaturated compound.

When the epoxy amount is less than 0.2% by weight, improvement in compatibility between the components (a) and (b) cannot be expected, and when it exceeds 15% by weight, the improvement in compatibility is not remarkable.

The amount of component (c) is 0.5 to 30 parts by weight, preferably 2 to 20 parts by weight, more preferably 5 to 15 parts by weight, based on 100 parts by weight of the total amount of components (a) and (b). Requires parts by weight. If the amount is less than 0.5 parts by weight, the compatibility of the components (a) and (b) cannot be improved, and if it exceeds 30 parts by weight, the compatibility is good, but the performance of the obtained composition is ( It is not preferable because it reflects the performance of the component c).

The present invention is an elastomer composition containing the above-mentioned components (a), (b) and (c), but to the extent that the properties of the resulting elastomer composition are not impaired, a styrene resin, a polyolefin resin, a poly Compounding oxymethylene resin, polyphenylene ether resin, etc., various plasticizers (oil, low molecular weight polyethylene, epoxidized soybean oil, polyethylene glycol, fatty acid esters, etc.), heat resistance stabilizer, light stabilizer, UV absorber, lubricant , Colorants, antistatic agents, release agents, halogen-containing polymers, aromatic halogen compounds, aromatic phosphates, red phosphorus, antimony trioxide, flame retardants, glass beads, calcium carbonate, talc, etc. By adding agents, conductive metal fibers, conductive carbon black, etc., various desired functions as a raw material can be imparted.

The elastomer composition of the present invention can be manufactured by various methods using the above-mentioned components. For example, a heating and melt-kneading method using a single-screw extruder, a twin-screw extruder, a roll, a kneader, a Brabender plastograph, a Banbury mixer and the like can be mentioned, but among them, the melt-kneading method using an extruder is most preferable. The kneading temperature at this time is not particularly limited, but usually can be arbitrarily selected from 150 to 300 ° C.

The elastomer composition of the present invention thus obtained can be molded into various molded articles by various conventionally known methods such as injection molding, extrusion molding, blow molding, calender molding and foam molding.

These various parts include, for example, high-pressure hoses, medical tubes, hydraulic / pneumatic tubes, fuel tubes, painting hoses, fire hoses, keyboard sheets, power / communication cable coating materials, computer wiring coating materials, automobiles. Wiring covering materials, various curl cords, boots for cars and vehicles, soft bumpers for cars, window frame sealing materials for cars,
It can be applied to packing, anti-vibration parts, bushes, grips, grip materials for automobile handles, etc.

(Effects of the Invention) The present invention significantly improves the poor compatibility (layer delamination), which tends to occur in a composition in which a hydrogenated block copolymer and polyurethane are conventionally compounded, and balances hardness and oil resistance. An improved elastomeric composition is provided.

(Examples) The present invention will be described in more detail with reference to examples, but 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 / cm2] and Tensile elongation [%] JIS-K6301, using a 2 mm thick injection sheet as the test sample, No. 3 test piece A dumbbell was used.

(3) Oil resistance Using No.3 test oil specified by JIS-K6301 at 70 ° C for 1 hour,
A 5 mm × 5 mm × 2 mm test piece was immersed, and the weight change (%) before and after immersion was determined.

(4) Presence or absence of delamination The test piece after the tensile test was observed.

Moreover, each compounded component is as follows.

(1) Preparation of hydrogenated block copolymer having a structure of hydrogenated polybutadiene-polystyrene-hydrogenated polybutadiene-polystyrene,
Bonded styrene content 35%, number average molecular weight 182,000, polybutadiene segment before hydrogenation 1,2 bond content 43%, hydrogenation rate 9
A 9% hydrogenated block copolymer was synthesized using a Ti-based catalyst described in JP-B-63-5401. The polymer obtained here is referred to as HTR.

Furthermore, having a structure of polystyrene-hydrogenated polybutadiene-polystyrene, bound styrene amount 33%, number average molecular weight 176,000, 1,2 bond amount of polybutadiene segment before hydrogenation 44%, hydrogenation rate 99% A hydrogenated block copolymer is synthesized by using a Ti-based catalyst described in JP-B-63-5401 to obtain an HTR.

Further, it has a structure of (polystyrene-hydrogenated polybutadiene) _4- Si, and has a bound styrene content of 20%,
The amount of 1,2 bonds in the polybutadiene segment before hydrogenation is 35
%, A number average molecular weight of 405,000 and a hydrogenation rate of 99% are synthesized using a Ti-based catalyst described in JP-B-63-4841 to obtain an HTR.

(2) Preparation of Polyurethane Elastomer Among commercially available thermoplastic polyurethane elastomers, Pandex T-5000V (manufactured by Dainippon Ink and Chemicals, Inc.) is used as TPU, and Miractolan P433 (manufactured by Nippon Miractoran Co., Ltd.) is used as TPU. And

(3) Preparation of epoxy-containing polymer After thoroughly replacing the inside of a stainless reactor equipped with a stirrer with nitrogen, 4,500 g of styrene and 500 of glycidyl methacrylate were prepared.
g, 100 g of sodium dodecylbenzenesulfonate, 25 g of t-dodecyl mercaptan, and 15,000 g of ion-exchanged water were charged into the reactor, and hot water of 70 ° C was circulated in the jacket, and the internal temperature was 60 ° C.
27.5g of potassium persulfate and ion-exchanged water 1,5
After adding 00g of aqueous solution and polymerizing for 150 minutes, styrene was added.
4,500 g, glycidyl methacrylate 500 g, sodium dodecylbenzene sulfonate 50 g, t-dodecyl mercaptan 25 g,
An aqueous solution of 5,000 g of ion-exchanged water, 27.5 g of potassium persulfate and 500 g of ion-exchanged water was added, and polymerization was further performed for 150 minutes. After completion of the polymerization, the polymer was coagulated with calcium chloride, thoroughly washed with water and dried to obtain a styrene-glycidyl methacrylate copolymer containing 10% by weight of glycidyl methacrylate. This polymer is designated as SG. Further, the composition of styrene and glycidyl methacrylate was changed by the same method to obtain a styrene-glycidyl methacrylate copolymer containing 0.8% by weight and 5% by weight of glycidyl methacrylate, respectively. Each polymer
SG, SG.

Furthermore, having a structure of polystyrene-hydrogenated polybutadiene-polystyrene, the bound styrene content is 45%, the number average molecular weight is 79,000, the molecular weight distribution is 1.03, and the 1,2-bond content of the polybutadiene portion before hydrogenation is 45%. A hydrogenated block copolymer with a rate of 99% was synthesized using a Ti-based catalyst described in JP-B-63-4841. With respect to 100 parts by weight of this hydrogenated block copolymer, 5.0 parts by weight of glycidyl methacrylate and di-t
1.2 parts by weight of ert-butyl peroxide was mixed to obtain 170
The denaturation reaction was carried out while performing forced venting (pressure reduction degree: 750 mmHg gauge pressure) using a vacuum pump with a 45 mmφ vented twin-screw extruder set to ℃. The modified hydrogenated block copolymer obtained was subjected to a reflux treatment for 20 hours with a Soxhlet extractor using acetone, and titration analysis of the epoxy value revealed that 2.6% by weight of glycidyl methacrylate was grafted. The polymer obtained here is designated as MHTR.

Then, using a 40-liter stainless steel reactor equipped with a stirrer, ethylene, glycidyl methacrylate, a radical initiator, and a chain transfer agent were continuously stirred, and stirred at 1400-1600 atm. Copolymerization under conditions of ~ 200 ℃, 6% by weight of glycidyl methacrylate
The contained ethylene-glycidyl methacrylate copolymer was synthesized. Let the polymer obtained here be EG.

Examples 1-9, Comparative Examples 1-4 Hydrogenated block copolymers, polyurethane elastomers, epoxy group-containing polymers, polypropylene resins (Asahi Polypropylene
M1300; manufactured by Asahi Kasei Kogyo Co., Ltd.) and rubber softener Diana Process Oil PW90 (manufactured by Idemitsu Kosan Co., Ltd.) were blended in the composition shown in Table 1 and melted with a 30 mm twin screw extruder set to 200 ° C. The elastomer composition was kneaded to obtain pellets. The pellets were injection-molded to obtain test pieces, each evaluation was performed, and the results are shown in Table 1.

From these results, the elastomer composition of the present invention has an excellent balance of hardness and oil resistance as compared with the elastomer composition containing the hydrogenated block copolymer and the polypropylene resin of Comparative Example, and even the low hardness elastomer composition has oil resistance. It became clear that it was excellent.

Further, although the layer separation is remarkable in the elastomer composition composed of the hydrogenated block copolymer containing no epoxy group-containing polymer and the polyurethane elastomer, the elastomer composition of the present invention containing the epoxy group-containing polymer is a layer. No peeling was observed.

Claims (1)

[Claims] 1. A polymer containing 0.5 to 10 parts by weight of (a) a hydrogenated block copolymer (b) a polyurethane elastomer, and (c) an epoxy group-containing polymer with respect to 100 parts by weight of the total amount of (a) + (b). An elastomer composition comprising 30 parts by weight.