Polycaprolactam/acrylic ester rubber thermoplastic elastic body
Technical field
The present invention relates to a kind of thermoplastic elastic material, particularly polycaprolactam/acrylic ester rubber thermoplastic elastic body.This elastomerics obtains by the twin screw extruder dynamic vulcanization, fusing point is up to 220 ℃, can under 175 ℃ environment, use continuously for a long time and have fabulous oil-proofness, be expected on heat-resisting and/or the demanding trolley part of oil resistant (as the parts under the automotive hood), to be applied.
Background technology
Thermoplastic elastomer (TPE) has the elastomeric property of traditional rubber and the thermoplastic processability of resin concurrently, can utilize existing resin treatment equipment and working method (as calendering, injection, blowing etc.) to carry out the rubber item manufacturing.The more important thing is, it can be carried out as resin and repeatedly process and be recycled and reused, the requirement that can greatly satisfy less energy-consumption processing, diversified processing, precision sizing, can repeat to process, being the important directions of rubber development, also is the preferred approach that solves Rubber processing and rubber recycling.
The preparation method of TPE has chemical synthesis and blending method.Blending method utilizes existing rubber and resin kind, carries out the multiple thermoplastic elastomer of reasonably combined production, is a kind of preparation method who has competitive power.Blending method is divided into simple blend method and dynamic vulcanization process, at present based on the latter.TPE with the dynamic vulcanization technology manufacturing often is called Thermoplastic Vulcanizate (TPV), compare with present synthesis type thermoplastic elastomer, have wide in variety, performance is wide, ageing-resistant performance is excellent, permanent set at high temperature is little, excellent in dimensional stability, performance characteristics such as approaching traditional vulcanized rubber more.
In the prior art, U.S. Mengshan all (Monsanto) company is the company (U.S. Pat 4130535 and US4311628) that obtains dynamic vulcanization thermoplastic ethylene-propylene rubber/polyolefine elastomer patent the earliest, but the life-time service temperature of dynamic vulcanization thermoplastic ethylene-propylene rubber/polyolefine elastomer can not surpass 135 ℃, can not life-time service with environment that deep fat contacts in.Chinese patent ZL01110732.4 has proposed to prepare with grease-proof paracril and polypropylene sulfuration the method for thermoplastic elastomer, Chinese patent ZL95197048.8 has proposed the method that a kind of solid phase grafting polymerization prepares polyolefine-polyacrylic ester thermoplastic elastomer, the thermoplastic elastomer that these two patents propose is compared the oil-proofness that has greatly improved material with the dynamic vulcanization thermoplastic ethylene-propylene rubber/polyolefine elastomer, but the life-time service temperature still can not be above 135 ℃.
Summary of the invention
The invention provides a kind of polycaprolactam/acrylic ester rubber thermoplastic elastic body of dynamic vulcanization, its objective is to obtain a kind of can be at 175 ℃ of following life-time service, the thermoplastic elastomer that has splendid oil-proofness simultaneously.
For achieving the above object, the technical solution used in the present invention is: a kind of polycaprolactam/acrylic ester rubber thermoplastic elastic body, and the component and the content of described thermoplastic elastomer are as follows:
Acrylic elastomer 20~80 parts by weight;
Polycaprolactam 80~20 parts by weight;
Linking agent 0.1~10 parts by weight;
Crosslinking coagent 0.1~10 parts by weight;
Softening agent 0.1~150 parts by weight;
Auxiliary agent 1~10 parts by weight;
Wherein:
The mooney viscosity of described acrylic elastomer (ML 1+4,100 ℃) is between 30~60;
Described polycaprolactam melting index MI is 0.5~30.0;
Described linking agent is an organo-peroxide, has to be selected from a kind of in following two kinds:
(1), 2, two (the tertiary butyl peroxidation)-2 of 5-, 5-dimethyl-3-hexin;
(2), 2, two (the tertiary butyl peroxidation)-2 of 5-, 5-dimethylhexane;
Described crosslinking coagent is diphenyl methane dimaleimide and/or 1,6-hexylene glycol double methacrylate;
Described softening agent is the above long-chain fat esters of 4 carbon, has to be selected from a kind of in following four kinds:
(1), Octyl adipate;
(2), Polycizer W 260;
(3), trioctyl trimellitate;
(4), citric acid dioctyl ester;
Described auxiliary agent comprises antioxidant 1010 or oxidation inhibitor 168.
Related content in the technique scheme is explained as follows:
1, in the such scheme, described auxiliary agent also comprises compatilizer, and this compatilizer is a polypropylene grafted maleic anhydride.
2, in the such scheme, described auxiliary agent also comprises lubricant, and this lubricant is the silicon cave.
3, the preparation method obtains by the twin screw extruder dynamic vulcanization, and the rotating speed of twin screw extruder is 200 rev/mins to 500 rev/mins, 180 ℃ to 260 ℃ of temperature.
The main physical properties of polycaprolactam/acrylic ester rubber thermoplastic elastic body proposed by the invention is as follows:
Hardness (Shao Shi) (ASTM D2240): 65A~50D;
Tensile strength (ASTM D412): 5.0~20.0Mpa;
Elongation (ASTM D412): 150%~350%;
Oil-proofness, volume change (ISO1817)
(IRM903,150 ℃ 336 hours) :≤10%;
The highest continuous use temperature (ASTM D794): 175 ℃.
Because technique scheme utilization, the present invention has following characteristics: in the processibility that keeps thermoplastics and the elastic while of rubber, the highest continuous use temperature is up to 175 ℃, and can be medium-term and long-term use of environment of 150 ℃ IRM 903 oil.
Embodiment
Below in conjunction with embodiment the present invention is further described:
Embodiment 1:
During preparation with 30 parts of polycaprolactams, 70 parts of acrylic elastomers, 1 part 2, two (the tertiary butyl peroxidation)-2 of 5-, the 5-dimethylhexane, 1.2 parts of diphenyl methane dimaleimides and part of auxiliary were mixed 5 minutes in the plastics mixing kettle, and the main spout of this mixture from twin screw extruder added; The intermediate zone of trioctyl trimellitate softening agent from twin screw is metered into, and the hardness of regulating product is to 75A.The temperature controlling range of twin screw extruder and mouthful mould is 180 ℃~260 ℃, and screw speed is controlled at 200rpm~350rpm.Performance sees Table 1.
Embodiment 2:
During preparation with 40 parts of polycaprolactams, 60 parts of acrylic elastomers, 1.0 part 2, two (the tertiary butyl peroxidation)-2 of 5-, the 5-dimethylhexane, 1.0 part 1,6-hexylene glycol double methacrylate and part of auxiliary were mixed 5 minutes in the plastics mixing kettle, and the main spout of this mixture from twin screw extruder added; The intermediate zone of trioctyl trimellitate softening agent from twin screw is metered into, and the hardness of regulating product is to 85A.The temperature controlling range of twin screw extruder and mouthful mould is 180 ℃~260 ℃, and screw speed is controlled at 200rpm~350rpm.Performance sees Table 1.
Embodiment 3:
During preparation with 55 parts of polycaprolactams, 45 parts of acrylic elastomers, 0.7 part 2, two (the tertiary butyl peroxidation)-2 of 5-, the 5-dimethylhexane, 0.85 part diphenyl methane dimaleimide and part of auxiliary were mixed 5 minutes in the plastics mixing kettle, and the main spout of this mixture from twin screw extruder added; The intermediate zone of trioctyl trimellitate softening agent from twin screw is metered into, and the hardness of regulating product is to 42D.The temperature controlling range of twin screw extruder and mouthful mould is 180 ℃~260 ℃, and screw speed is controlled at 200rpm~350rpm.Performance sees Table 1.
Comparative example 1:
During preparation with 45 parts of polypropylene, 55 parts of terpolymer EP rubbers, 1.5 parts of SP-1045 octyl phenol urea formaldehydes, 0.3 part of tin protochloride and part of auxiliary were mixed 5 minutes in the plastics mixing kettle, and the main spout of this mixture from twin screw extruder added; The intermediate zone of naphthenic oil softening agent from twin screw is metered into, and the hardness of regulating product is to 85A.The temperature controlling range of twin screw extruder and mouthful mould is 140 ℃~200 ℃, and screw speed is controlled at 200rpm~350rpm.Performance sees Table 1.
The performance data of table 1: embodiment and comparative example
Project | Detection method | Embodiment 1 | Embodiment 2 | Embodiment 3 | Comparative Examples 1 |
Hardness | ASTM D2240 | 75A | 85A | 42D | 85A |
Tensile strength | ASTM D412 | 6.2 | 8.0 | 10.4 | 8.2 |
Elongation | ASTM D412 | 170 | 180 | 170 | 420 |
The highest continuous use temperature | ASTM D794 | 175 ℃ | 175 ℃ | 175 ℃ | 135 ℃ |
Volume change (150 ℃, IRM903,336 hours) | ISO1817 | 6.5 | 6.0 | 4.6 | Structure is destroyed, and is shapeless. |
As can be seen from Table 1, the maximum operation (service) temperature of the polypropylene of comparative example/terpolymer EP rubber thermoplastic elastomer has only 135 ℃, and in 150 ℃ IRM903 oil the bubble 336 hours after structure destroy, do not have use value; And the maximum operation (service) temperature of thermoplastic elastomer of the present invention (embodiment 1,2,3) reaches 175 ℃, and can use in 150 ℃ IRM903 oil.
The foregoing description only is explanation technical conceive of the present invention and characteristics, and its purpose is to allow the personage who is familiar with this technology can understand content of the present invention and enforcement according to this, can not limit protection scope of the present invention with this.All equivalences that spirit is done according to the present invention change or modify, and all should be encompassed within protection scope of the present invention.