Dynamically partially cured organic peroxides thermoplastic elastomer composition

 

(57) Abstract:

Usage: as a thermoplastic elastomeric composition. The inventive Product: dynamically partially cured organic peroxides thermoplastic elastomer composition comprising crystalline polypropylene (a), an amorphous ethylene-propylene copolymer rubber (b), semi-crystalline, low density linear ethylene-propylene copolymer with ethylene content of more than 90% (c) and polybutylene-1 /d/. 6 C.p. f-crystals, 2 tab.

The invention relates to dynamically partially utverzhdenii thermoplastic elastomer composition.

Known rubber polymer mixture of polybutene-1, copolymer of polyolefin and monoolefins. U.S. patent N 4078020 reveals a composition comprising uncured copolymer of ethylene and higher alpha-olefin, which optionally contains (a) up to 5% of a diene, (b) crystalline stereoregularity polypropylene and (c) crystalline stereoregular a homopolymer of butylene-1. The composition according to this source are not stitched.

Also known composition of a polymer of butylene-1 and the cured or partially cured thermoplastic elastomer. For example, U.S. patent is uchitelnoj least (80-90%) utverzhdennuyu a mixture of (1) a copolymer of ethylene, polyene and at least one monoolefins having at least three carbon atoms (EPDM), (2) polyethylene and (3) optionally at least one polymer monoolefins having at least three hydrocarbon atom, preferably polypropylene. In U.S. patent N 4247652 disclosed thermoplastic elastomer mixture containing (A) dynamically utverzhdennuyu elastomer composition, which contains (i) a peroxide-curable olefin copolymer rubber (ii), peroxide degradable olefin plastic, in which the sum of (i) and (ii) is 100 hours, and (iii) a non-peroxide-curable hydrocarbon elastomeric material and/or (ii) mineral oil (b) olefinic plastic. In both of these patents butylene polymer blended with a thermoplastic elastomer composition, which overiden or partially overiden before adding the polymer of butylene-1.

In U.S. patent N 4650830 described dynamically partially cured thermoplastic elastomer composition containing (A) an amorphous copolymer of ethylene and alpha-olefin and (B) a polymer selected from the group including (i) nizkoglikemichesky copolymer of propylene with an alpha olefin having at least 4 carbon atoms, (ii) a homopolymer or copolymer of 1-butyl is at least three carbon atoms. Preferably the partial cross-linking is carried out graft copolymerization of a monomer polymerizable by radical type and having at least two capable of polymerization group.

It was found that the addition of polybutylene-1 and compositions of thermoplastic elastomers and dynamic partial cure give compositions having increased tear resistance, elongation, melt viscosity and useful for the manufacture of moulded or extruded products, such as industrial hoses, car parts and sheet materials.

Thus, the invention provides for dynamically partially cured thermoplastic elastomer, containing by weight (a) from 20 to 70 hours propylene polymer material, (b) from 20 to 60 hours of amorphous ethylene-propylene copolymer rubber (EPR), (c) from 8 to 30 hours semi-crystalline, low density, substantially linear ethylene-propylene copolymer, in which the total amount of components (a), (b) and (c) is 100 hours, and (d) from 2 to 20 hours polybutylene-1 at 100 PM (a) + (b) + (c), the ratio of polybutylene-1 to the component (b) is less than 0.5.

If not defined specifically, all parts and percentages in the description of the component (a), includes (i) a crystalline polypropylene having an isotactic index of more than 90%, preferably from 95 to 98% and (ii) ethylene-propylene random copolymer having an ethylene content of up to 10%, preferably from 1 to 3% and 90-94% insoluble in acid at room temperature. Propylene polymer material is present in an amount of from 20 to 70 hours and preferably from 30 to 50 hours

Component (b) according to the invention is an amorphous ethylene-propylene copolymer rubber having an ethylene content of 40 to 70% of ethylene-Propylene copolymer rubber is present in an amount of from 20 to 60 hours, preferably from 30 to 50 hours

Semi-crystalline, low density, substantially linear ethylene-propylene copolymer of component (c) essentially contains more than 90% of elementary units of ethylene, preferably more than 95% and not soluble in xylene at room temperature. The term "semi-crystalline" used in the description, is defined as the crystallinity of from 20 to 60% is preferred from 25 to 50% as measured by the heat of fusion of component (c), which is defined differential scanning calorimetry sample component (c) weighing from 5 to 10 mg is heated at a rate of 20oC is described U. Jaur and B. Wiinderlich, Phys. Chem. Ref. Data, 10 (1), 119 (1981). The percent crystallinity is calculated by dividing the heat of fusion of component (c) a heat of fusion of 100% crystalline polyethylene and multiplying by 100. Component (C) is present from 8 to 30 hours, preferably 10 to 20 hours

The total amount of components (a) + (b) + (c) in the compositions according to the invention is 100 hours

Polybutylene-1 component (d) is a crystalline stereoregular a polybutylene, having a density of from 0,914 to 0,919 g/cm3with melt index from 1 to 100 g/10 min Polybutylene-1 is present in the composition according to the invention in quantities of from 2 to 20 hours, preferably from 4 to 15 hours per 100 hours of components (a) + (b) + (c). The ratio of polybutylene-I to component (b) should be less than 0.5, preferably from 0.1 to 0.3.

Partial curing of the composition is carried out using a peroxide curing system containing an organic peroxide, and at least one auxiliary cross-linking agent selected among the 1,2-polybutadiene and furan derivatives of the formula:

< / BR>
where

X represents a radical of the formula-CHO, -COOH, -CHONH2, -CN, -NO2,

-CH2COCH2COOR, -CH(COOR)2,

where

R oznacza what is the number equal to the free valence of the radical X, R1and R2identical or different, represent hydrogen, alkyl with 1 to 4 carbon atoms or a cyclo-alkyl containing 5 to 8 carbon atoms.

Peroxide crosslinking agent should have a half-period of existence from 3.3 to 20 min, preferably from 7 to 18 minutes at 160oC in the ternary ethylene-propylene-diene monomer rubber (ERDM). Suitable examples of the peroxides used in the present invention include 1,1'-bis-(tert-butylperoxyisopropyl)-benzene, peroxide Dicumyl, n-butyl-4,4'-bis-(tert-BUTYLPEROXY)-valerate, and 2,5-di(tert-BUTYLPEROXY)-2,5-dimethylhexane. Peroxide is present in the amount up to 100 hours component (a) + (b) + (c), from 0.5 to 3.0 hours, preferably from 1.0 to 2.5 hours and in liquid or solid supported form and are commercially available materials.

1,2-Polybutadiene has a mol. m is at least 1300, up to 13,000, preferably at least from 2400 up to 13,000. The content of 1,2-vinyl is at least 50% and preferably from 50 to 90, and most preferably from 70 to 90% of the Amount present in the composition of the 1,2-polybutadiene is from 2 to 20 hours, preferably from 4 to 12 hours at 100 including components (a) + (b) + (c). yobretenie material in both forms.

Furan derivatives of the above formulas that can be used in the invention are known in this field and can be obtained by the method described in U.S. patent N 2738338 listed in the bibliographic reference. Suitable examples include 1,5-difurfuryl-1,4-pentadien-3-one, debentureholder, a-furyl)-acrolein, 5-(a-furyl)-pentadienyl, a-forelectronic, a-forelectronics, b -( a-furyl)-acrylic acid and its esters of furfurylamine and the like. Derivatives of furan is used in amounts of from 0.15 to 3.0, preferably from 0.17 to 2.0 hours per 100 hours of components (a) + (b) + (c).

Dynamically partially cured thermoplastic elastomer according to the invention is produced by adding the peroxide curing system to the mixture of components (a) + (b) + (c) and (d) and subjecting this mixture to the influence of curing conditions and rubbing the mixture to bring it to the desired dynamically partially cured.

Components (a), (b) and (c) form a homogeneous mixture, obtained by first polymerizing propylene with the formation of component (a) and then polymerizing propylene and ethylene in the presence of component (a) with the formation of components (b) and (c) in a separate reactor or in a series raunatinom embodiment, components (a), (b) and (c) can be each prepared separately and then mixed in the melt with chafing.

The term "partially cured", as used in the description means that the degree of cure determined by the gel content is at least 80% but not more than 94% in cyclohexane according to the test, see below. Preferably the gel content of from 85 to 92%

The temperature of mixing and/or grinding is in the range from 160 to 225oC, preferably 180 215oC, during the time from 2 to 30 min, preferably from 3 to 20 min to get a dynamically partially cured thermoplastic elastomer according to the invention. When the above-mentioned curing conditions at least 97% of the curing agent is depleted, usually 98 to 99% of theoretical half-period of existence 160oC triple ethylenepropylene rubber (ERDM). The process of grinding or shearing strain can be performed in an open rotating the cylinder, a closed mixer (e.g., Banbury mixers or Haake) and in single - or twin-screw injection machine.

Upon receipt of thermoplastic elastomer of the present invention is a homogeneous mixture of components (a), (b) and (c) is prepared in two stages, as is alistar and procedure described in application for U.S. patent N series 515936, registered on April 27, 1990, the thus Obtained homogeneous mixture was added to component a and mix until the formation of homogeneous mixture. Then add an adjuvant to crosslinking, i.e., furan production or 1,2-polybutadiene and the stirring is continued for approximately 1-2 minutes, 1,2-polybutadiene can be used in liquid or solid form. If the 1,2-polybutadiene is added in liquid form, which usually add in small increments from 25 to 50% over time from 2 to 5 min, and if it is added in the form of solids, then add all once. Then add the peroxide and mix to achieve a constant viscosity, about 5-7 min, which shows that essentially all the peroxide consumed. The chafing continue then further 1-2 minutes

Preferably thermoplastic elastomer according to the invention receive a preliminary mixing of all components. According to this method, all components are pre-mixed in a tilting drum, for example in the mill Hensely or in a V-shaped mixer. Then the premix is loaded into the camera, a powerful mixer, mix to achieve ptx2">

In addition curing system may contain other sommerdale, such as phenylene-bis-maleimide and/or sulfur donors, such as mercaptobenzothiazoles, benzothiadiazole, tetramethylthiuram-monosulfide, tetramethylthiuramdisulphide, dipentylester-execulive, N, N-diethyltoluene, alkylphenolethoxylate and dibutyldithiocarbamate zinc. A number of other sommerdale used in the system, is in the range of 0.5 to 3.0 hours, preferably from 1.0 to 2.5 hours and the number of donors of sulphur in the range from 0.15 to 3.0, preferably from 0.17 to 2.0 hours at 100 including components (a) + (b) + (c). Donors sulfur and phenylene-bis-maleimide used in the present invention, are commercially available.

If curing system contains additional coommercial and/or a sulfur donor, coommercial usually added together with the 1,2-polybutadiene and the donor sulfur is usually added in combination with the peroxide.

In addition to these main components in thermoplastic elastomer typically antioxidant is present in amount of from 0.1 to 0.98 hours per 100 hours of components (a) + (b) + (c). Suitable examples of antioxidants used in the invention are thiophenol, 4,4'-thio-bis(6-tert-butyl-meta-cresol); Ftan; thiodipropionate, dilaurentiis; hydrochinone, 2,5-di-tert-butylhydroquinone and quinoline, 2,2,4-trimethyl-1,2-dihydroquinoline, are all commercially available materials. Thermoplastic elastomer according to the invention may also contain other conventional additives, for example filled with oils such as paraffinic and naphthenic oils in amounts of from 20 to 100 hours, preferably from 25 to 60 hours, and most preferably from 25 to 50 hours per 100 hours-propylene rubber; or zinc oxide in an amount of from 2 to 6 hours at 100 including components (a) + (b) + (c).

Protivookislitelnoj, as equal as any other conventional additives, such as zinc oxide or additional antioxidants added before the introduction of the peroxide. If thermoplastic elastomer obtained by the method of preliminary displacement, then filled the oil is added after the premix is loaded into the mixer and melt ingredients began.

The invention will be further illustrated in more detail with reference to examples of embodiment of the invention presented below. The physical properties of the compositions in the following working examples and comparative examples were measured as follows:

The tensile strength when the>The shore hardness ASTM D-2240

The residual strain compression ASTM D-395, method B 30

The viscosity of the melt 110ASTM D-1283, 230oC, 10 kg

The percentage of gel was determined by impregnation of the weighted sample size 3,81 cm x 1.9 cm x 0,20 cm in 100 ml of cyclohexane at 23oC for 48 h, the removal of the test sample and drying to constant weight (about 72 h) in a vacuum oven at 90oC. the Percentage of the gel was determined by the formula:

< / BR>
Example 1. This example illustrates the partially cured thermoplastic elastomer according to the invention and the method thereof.

To a mixture of 40 hours of crystalline polypropylene having an index of stereoregularity about 92, 40 including ethylene-propylene copolymer rubber having an ethylene content of about 50% and 20 hours semi-crystalline, low density, substantially linear ethylene-propylene copolymer which is insoluble in xylene at room temperature and having an ethylene content of 96% is obtained as described above, in the mill Hensely was added 6 hours of polybutene, 5,5 including 1,2-polybutadiene, 4,2 parts of 1,1-bis(tert-BUTYLPEROXY)-diisopropylbenzene, 6 hours zinc oxide, and 0.7 hours of mercaptobenzothiazoles, 2 h N, N'-phenylene-bis-Melamid and 0.3 PM 4,4'-times was then downloaded into the tank closed Haake mixer (model A), preheated to a temperature of 182oC, stirred for approximately 1-3 minutes at the aforementioned temperature. Added 5 tsp oil and stirring is continued for 30-60 sec, then added the remaining 5 hours of the oil. Stirring is continued additionally during 45-70 with and then added to 0.4 hours tetrakis-(methylene-(3,5-di-tert-butyl-4-oxyhemocyanin)-methane. Mixing continued until a homogeneous mixture.

The mixture is then loaded into the mold was sealed and was formed by hot molding of 10.5 MPa at 215oC for 3 minutes the mold was removed from the hot press and placed in a press at room temperature and cooled under pressure of 10.5 MPa for 15 min, then removed for testing.

Physical properties of the material are presented in table. 1.

The example for comparison 1. 30 hours of polypropylene, 60 including ethylene-propylene-ethylidene-norbornene rubber, with 55% of ethylene, 4,4% of the diene, the viscosity Mooney viscometer 70, commercially available, and 10 o'clock linear low density polyethylene having a density of 0,930 and a melt index of 1.0, commercially available material was injected into a closed Haake mixer and mixed for approximately 2 min before dilution with 187-193oC primer is 0.1 to parts of 4,4'-thio-bis(6-tert-butyl-meta-cresol) and stirred additionally for 1 to 2 minutes The obtained partially crosslinked thermoplastic elastomer had a gel content 94.7% of

100 hours obtained above partially crosslinked thermoplastic elastomer was added to 25 hours of polybutene-1 and the mixture was stirred for about 2-3 minutes at a temperature of 190oC. Samples of the molding obtained according to the procedure described in example 1. Physical properties are presented in table. 1.

Example 2. Dynamically partially cured thermoplastic elastomer was obtained by the same method and from the same ingredients as in example 1, except that used an additional 5 hours of polypropylene, 4 hours of polybutylene-1 instead of 6 hours of polybutene-1 and /methylene-(3,5-di-tert-butyl-4-oxyhemocyanin)-methane were added around the same time with the polybutylene instead of after the last oil supplements. Physical properties are presented in table. 2.

Example 3. Dynamically partially cured thermoplastic elastomer was obtained in the same manner and from the same ingredients as in example 2, except that used 6 hours of polybutene-1. Physical properties are presented in table. 2.

The example for comparison 2. Dynamically partially cured thermoplastic elastomer was obtained by the method and ingredient of the

As specific embodiments of the invention described in sufficient detail, variations and modifications can be made within the scope of the invention described and claimed in the claims.

1. Dynamically partially cured organic peroxides thermoplastic elastomer composition comprising crystalline polypropylene (a), an amorphous ethylene-propylene copolymer rubber (C), semi-crystalline, low density linear ethylene-propylene copolymer (C), characterized in that the composition as ethylene-propylene copolymer includes insoluble in xylene at room temperature, ethylene-propylene copolymer with ethylene content of more than 90% and the total amount of components (a) + (b) + (C) is 100 mass. parts and additionally contains 4 to 15 wt. parts of polybutylene-1 (d) per 100 parts (a) + (b) + (C), where the ratio of polybutylene-1, the rubber is less than 0.5 in the following ratio, wt.

(a) 30 50

(in) 30 50

(C) 10 20

(d) 4 15

2. The composition according to p. 1, characterized in that the content of the crystalline polypropylene is 40 am

3. The composition according to p. 1, characterized in that the content is different, however, that the content of semi-crystalline, low density linear ethylene-propylene copolymer is 20 hours

5. The composition according to p. 1, characterized in that the content of the polybutylene-1 is 4 to 6 o'clock

6. The composition according to p. 1, characterized in that it contains (a) 40 45 PM crystalline polypropylene, (b) 30 50 PM amorphous ethylene-propylene copolymer rubber, (C) 10 18 including semi-crystalline, low density linear ethylene-propylene copolymer and (d) 4 15 hours per 100 hours (a) + (b) + (C) of polybutylene-1.

7. The composition according to p. 1, characterized in that it contains (a) 40 hours of crystalline polypropylene, (b) 40 hours of amorphous ethylene-propylene copolymer rubber, (C) 20 o'clock semi-crystalline, low density linear ethylene-propylene copolymer and (d) 4 6 parts of polybutylene-1 100 including components (a) + (b) + (C).

 

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