JPH0625495A - Elastomer composition based on vinyl chloride resin - Google Patents

Abstract

PURPOSE:To provide an elastomer compsn. excellent in compression set, low- temp. flexibility, moldability, and resistances to bleeding and blocking. CONSTITUTION:100 pts.wt. resin component comprising 95-50 pts.wt. vinyl chloride resin and 5-50 pts.wt. chorinated polyethylene is compounded with 20-400 pts.wt. NBR contg. tetrahydrofuran-insol. crosslinked part and 10-300 pts.wt. plasticizer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride resin elastomer composition having excellent compression set, creep resistance and low temperature characteristics.

[0002]

2. Description of the Related Art The demand for improved performance of elastomer materials is increasing year by year, and particularly in the automobile field, excellent compression set is required as a material for glass run channels and drainers. Conventionally, soft vinyl chloride resin has a soft rubber-like feel as these materials, has excellent moldability, weather resistance, colorability, etc. compared to vulcanized rubber, and has been widely used from the viewpoint of cost. It was However, its compression set is inferior to that of vulcanized rubber, and its softening temperature is low, which limits its use at high temperatures. Therefore, attempts have been made to improve the vinyl chloride resin to have a high degree of polymerization, but no satisfactory one has been obtained.

The applicant of the present invention kneads a composition consisting of a vinyl chloride resin, a plasticizer and a rubber-like substance together with an organic peroxide to improve the compression set and to form the resin in comparison with the vinyl chloride resin. Method for producing a vinyl chloride resin-based thermoplastic elastomer whose property does not change Japanese Patent Application No. 60-37205
Although the elastomer has an excellent compression set, it has not been able to keep up with the recent trend of requiring low temperature characteristics, and improvement of low temperature characteristics has been awaited. The elastomer of the invention according to the above-mentioned application is a phenomenon in which the vinyl chloride resin itself has a strong polarity and a strong cohesive force of molecules, and therefore has a large temperature dependence on the low temperature side and becomes hard when cooled and a large hardness change. There is. For example, when this elastomer is used as a sealing material for moving parts such as weather strips for automobiles, it shows flexibility at room temperature, but when it reaches a temperature as low as -20 ° C, it cures and rubber elasticity decreases, resulting in a sealing property. Is causing the deterioration.

Further, for the purpose of improving fuel oil extraction resistance such as gasoline extraction resistance, an invention of a method for producing an elastomer composition containing chlorinated polyethylene, a plasticizer, a vinyl chloride resin and a partially crosslinked NBR is disclosed. As disclosed in JP-A-63-309546, since chlorinated polyethylene is the main resin component, the bleeding phenomenon of the plasticizer is unavoidable.
There is a drawback that the molded product is contaminated and blocking occurs when the molded products are stacked, and the technical idea of improving compression set, creep resistance and low temperature characteristics is not shown in this invention.

Further, for the purpose of obtaining a molding resin composition having a well-balanced performance in mechanical properties, thermal stability, low temperature properties and processability, polyvinyl chloride, butadiene copolymer, chlorinated polyethylene and polyester resin are used. An invention comprising a plasticizer is disclosed in JP-A-50-145454. However, since the butadiene-based copolymer does not have a crosslinked structure, it is not satisfactory in terms of compression set and creep resistance. There wasn't.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have found that a vinyl chloride resin as a main resin component is excellent in compression set, has good moldability, and has no plasticizer bleeding or blocking of a molded article and a little. However, as a result of extensive studies aimed at obtaining a vinyl chloride resin-based elastomer composition having excellent low-temperature flexibility, a part of the vinyl chloride-based resin of an elastomer composed of a vinyl chloride-based resin, a partially crosslinked rubber substance and a plasticizer was chlorine-containing. It has been found that the above object can be achieved by substituting a modified polyethylene for the purpose of completing the present invention. An object of the present invention is to provide a vinyl chloride resin elastomer composition having excellent compression set, low temperature flexibility, moldability, bleed resistance and blocking resistance, and a method for producing the same.

[0007]

The gist of the present invention is that 95 to 50 parts by weight of vinyl chloride resin and 5 to 50 parts by weight of chlorinated polyethylene, and 100 parts by weight of these resins in total are crosslinked with tetrahydrofuran insoluble. N containing ingredients
A vinyl chloride resin elastomer composition comprising 20 to 400 parts by weight of BR and 10 to 300 parts by weight of a plasticizer.

The present invention will be described in detail. The vinyl chloride resin, which is the main resin component of the elastomer composition of the present invention,
All of vinyl chloride or a mixture of vinyl chloride and a comonomer copolymerizable therewith, which are produced by a usual method such as a suspension polymerization method, a bulk polymerization method, a fine suspension polymerization method or an emulsion polymerization method can be used. Examples of comonomers include vinyl acetates such as vinyl acetate, vinyl propionate, vinyl laurate, acrylic acid esters such as methyl acrylate, ethyl acrylate and butyl acrylate, and methacrylic acid esters such as methyl methacrylate and ethyl methacrylate.

Maleic acid esters such as dibutyl maleate and diethyl maleate, fumaric acid esters such as dibutyl fumarate and diethyl fumarate, vinyl ethers such as vinyl methyl ether, vinyl butyl ether and vinyl octyl ether, acrylonitrile and methacryloyl ester. Vinyl cyanide such as nitrile, α-olefins such as ethylene, propylene and styrene, vinylidene chloride, vinylidene halide other than vinyl chloride such as vinyl bromide, vinyl halides, diacrylic phthalate, ethylene glycol dimethacrylate, etc. And the comonomers are not limited to those described above. The comonomer content is 30% by weight or less, preferably 20% by weight or less in the constituent components of the vinyl chloride resin.

The average degree of polymerization of the vinyl chloride resin is not particularly limited, but is 70 from the viewpoint of workability, moldability and the like.
It is desirable to be in the range of 0 to 8000, preferably 1300 to 3500. Chlorinated polyethylene, which is one resin component of the elastomer composition of the present invention, is a powder of an ethylene homopolymer such as high-density polyethylene or low-density polyethylene or a copolymer of ethylene and an α-olefin copolymerizable with ethylene. It can be obtained by introducing chlorine gas under suspension in the vicinity of its softening temperature to chlorinate. It may also be produced by dissolving the polymer in a solvent and reacting chlorine gas in the presence of a catalyst. It is preferable to use a chlorinated polyethylene having a chlorination degree of 20 to 45%.

The amount of chlorinated polyethylene added is 5 to 50% by weight of the resin component, that is, 95 to 50 parts by weight of the above vinyl chloride resin and 5 to 50 parts by weight of chlorinated polyethylene, for a total of 100 parts by weight. It is necessary to.
If it is less than 5 parts by weight, the effect of improving low temperature flexibility cannot be expected, while if it is more than 50 parts by weight, the plasticizer bleeds onto the surface of the molded product. In addition, the pellets stick (bridge) and do not easily bite into the molding machine, which causes a problem in moldability.

N contained in the elastomer composition of the present invention
BR needs to contain an insoluble cross-linking component in tetrahydrofuran (hereinafter referred to as THF), a so-called gel content, and the gel content is preferably 30% by weight or more, and particularly preferably 50% by weight or more of NBR. The gel content is N
To 1 g of BR sample, 40 cc of THF at 25 ° C. was added with stirring and then allowed to soak and stand, and after 12 hours, the supernatant TH
Remove F. This operation is repeated 8 times, and the insoluble residue is dried and then calculated from its weight.

The THF insoluble crosslinking component in NBR is NB
It is preferable that R is contained from the beginning, and it is more preferable that the NBR added by blending the crosslinking agent at the time of preparing the elastomer composition and the crosslinking agent undergo a crosslinking reaction during kneading to further increase the gel content. . Of course, NB that does not contain gel
A gel component may be produced by reacting R with a crosslinking agent. For the former, commercially available NBR containing gel is used as it is, and for the latter, vinyl chloride resin, chlorinated polyethylene, NBR,
The NBR and the crosslinking agent are reacted during the preparation of the elastomer composition by heating and kneading a compound such as a crosslinking agent and a plasticizer.

The cross-linking agent used for cross-linking the above NBR is, for example, cumene hydroperoxide,
Organic peroxides such as 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, quinone derivatives such as p-quinonedioxime, p, p'-dibenzoylquinonedioxime, bromomethylalkylation Phenolic resins such as phenolic resins, amine compounds such as 1,6-hexamethylenediamine and triethylenetetramine are used,
Usually, a crosslinking accelerator and an antioxidant are used together. The amount of the crosslinking agent used is 0.05 to 1 per 100 parts by weight of the resin component.
It is preferably in the range of 0 parts by weight, and particularly in the range of 1 to 5 parts by weight.

Examples of the crosslinking accelerator include aldehyde amines such as n-butyraldehyde amine, thioureas such as N, N'-diphenylthiourea, di-o-triguanidine, and 1,3-diphenylguanidine. Guanidine compounds, 2-mercaptobenzothiazole compounds, thiazole compounds such as dibenzothiazyl disulfide, tetramethylthiuram disulfide compounds, thiuram compounds such as tetraethylthiuram disulfide compounds, N-cyclohexyl-2-benzothiazylsulfenamide, N-oxydiethylene-2 -Sulfenamides such as benzothiazolylsulfenamide, zinc dimethyldithiocarbamate, N-ethyl-N
-Dithiocarbamate salts such as zinc phenyldithiocarbamate and the like can be mentioned, and examples of the antiaging agent include 6-ethoxy-1,2-dihydro-2,2.
4-trimethylquinoline, phenyl-1-naphthylamine, octylated diphenylamine, 2,6-di-t-butyl-4-methylphenol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2- Examples include mercaptobenzimidazole and the like.

However, the blending ratio of NBR is in the range of 20 to 400 parts by weight, preferably 50 to 300 parts by weight, relative to 100 parts by weight of the above-mentioned resin component. If the amount is more than 400 parts by weight, the shapeability is poor and the extrusion moldability is poor and the molded product suffers from edge cutting (edge breakage).

The elastomer composition of the present invention, when used in combination with a plasticizer, softens the composition to facilitate kneading and processing, and serves to improve compression set. The plasticizer is not particularly limited, and examples thereof include di-2-
Ethylhexyl phthalate, di-n-octyl phthalate, diisodecyl phthalate, dibutyl phthalate, dihexyl phthalate and other phthalate ester plasticizers; dioctyl adipate, dioctyl sebacate and other straight chain dibasic ester plasticizers; trimellitate ester Plasticizer; Polyester polymer plasticizer; Epoxidized soybean oil, epoxidized linseed oil, liquid epoxy resin and other epoxy plasticizers; Triphenyl phosphate, trixylyl phosphate, tricresyl phosphate and other phosphate ester plasticizers And one or more of these are mixed and used.

Although the amount of the plasticizer used varies depending on the type and amount of vinyl chloride resin, chlorinated polyethylene, NBR, etc., the presence or absence of a filler, etc., it is 10 to 300 parts by weight per 100 parts by weight of the resin component. Parts, preferably 40 to 200 parts by weight.

It is desirable to add a filler to the elastomer composition of the present invention within a range that does not impair the compression set. The filler absorbs an excessive amount of plasticizer and is kneaded,
Has the effect of smoothing the molding. Examples of the filler include carbon black, calcium carbonate, titanium oxide, talc, aluminum hydroxide, magnesium hydroxide, hydrotalcite, clay, silica and white carbon. The amount of the filler added is 600 parts by weight or less, preferably 10 to 550 parts by weight, based on 100 parts by weight of the resin component. If the addition amount of the filler is too small, the effect of improving kneading and moldability is small, and if it is more than 600 parts by weight, the moldability tends to be deteriorated, and it is economical to add it within a range that does not impair the moldability. It is also desirable from the viewpoint of sex.

Further, the extrusion moldability can be improved by adding an acrylic resin to the elastomer composition of the present invention. Acrylic resin refers to those obtained by polymerizing acrylic acid or its derivatives, acrylic acid,
Examples thereof include polymers or copolymers of acrylic acid ester, acrylamide, acrylonitrile, methacrylic acid, methacrylic acid ester and the like. In particular, the elastomer composition of the present invention is a copolymer of methyl methacrylate and alkyl acrylate, the former being 60% by weight or more, preferably 70 to 90% by weight and the latter 40% by weight or less, preferably 30% by weight. It is suitable to use one in the range of 10% by weight. The amount of acrylic resin added is preferably in the range of 1 to 30 parts by weight, preferably 5 to 20 parts by weight, based on 100 parts by weight of the total amount of vinyl chloride resin and chlorinated polyethylene.

Further, in the elastomer composition of the present invention, if necessary, stabilizers, lubricants, antioxidants, ultraviolet absorbers, foaming agents, flame retardants, pigments, impact modifiers, thermoplastic resins other than those mentioned above, etc. You may mix | blend various additives. The vinyl chloride resin elastomer composition of the present invention comprises a vinyl chloride resin, chlorinated polyethylene, NBR containing a THF-insoluble crosslinking component, a plasticizer, and various other additives such as an acrylic resin and a filler in a predetermined amount or a mixer. Put in the kneader and put 1
Mix and knead while heating at a temperature of 00 to 230 ° C, preferably 130 to 230 ° C, or vinyl chloride resin, chlorinated polyethylene, uncrosslinked or partially crosslinked NB
It is produced by a method of uniformly mixing and kneading R and a predetermined amount of a crosslinking agent, a plasticizer, an acrylic resin, a filler and the like.

The elastomer composition of the present invention is preferably manufactured, for example, by the following method from the viewpoint of operation or obtaining a uniform kneading composition. That is, first, a blend comprising a vinyl chloride resin and a plasticizer and optionally an acrylic resin is dry blended in advance, and then the dry blend is NBR, preferably NBR containing a THF insoluble crosslinking component, chlorinated polyethylene. And, if necessary, other additives such as a cross-linking agent and a filler at 100 to 230 ° C.
Mix and knead while heating to the temperature.

The equipment used to mix the above-described ingredients may be any equipment that allows for substantially uniform mixing, such as a Henschel mixer, ribbon blender,
A planetary mixer or the like can be used. To knead the mixture, for example, an extruder, roll, Banbury mixer, kneader, or other device capable of kneading under heating while being heated is used. In the method of increasing the gel content of NBR at the time of producing the elastomer composition, it is preferable to use a closed kneader such as a Banbury mixer, an intensive mixer, a pressure kneader or the like or a co-direction twin-screw extruder because the kneading effect is large.

By using these kneaders, the crosslinking agent, for example, decomposition gas of organic peroxide, does not diffuse out of the kneader, so that the reaction efficiency is improved in combination with the kneading effect, and the gel content of NBR is excellent. The concentration can be increased. If the kneading temperature is lower than 100 ° C., the progress of the crosslinking reaction is slow, and it takes a long time to reduce the productivity, and if the kneading temperature is higher than 230 ° C., the elastomer composition is easily decomposed.

[0025]

EXAMPLES Next, the composition of the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples without departing from the gist thereof. The vinyl chloride resin-based elastomer composition was evaluated for quality as follows and shown in Table 1. Measurement of compression set: 70 ° C according to JIS K6301
× 22 hours, measured at 25% compression condition. Low temperature flexibility: Apparent torsion modulus is 1.0 in the low temperature torsion test method based on JIS K6301.
The temperature is shown when it reaches × 10 ³ kg / cm ² .

Extrudability: Pellets of the elastomer composition were extruded with a 20 mmφ extruder into a flat belt having a thickness of 0.5 mm and a width of 20 mm at a temperature of 180 ° C., and the edge breakage of the molded product was visually judged. In addition, the surface of the molded product is wavy (uneven)
Was also observed. ◎ Extrusion molding is extremely easy, no edge breakage and no waviness. ○ Edges are not broken and there is no waviness. △ Some edge breakage or waviness is observed. × Something has broken edges.

Heating test of molded product: According to the bleeding resistance test method, a 2 mm thick press sheet was left to stand in a thermo-hygrostat at 50 ° C. and 60% relative humidity for 1 week, and then taken out at 23 ° C. The surface change of the molded article after being left for 1 hour was visually observed. ○ No change on the surface such as bleed. × There is bleeding or some rough skin is observed on the surface.

Blocking resistance: A polyethylene bag of 12 cm × 10 cm is filled with about 200 g of pellets and laid down, and a weight is placed on the pellet, and 200 g including the flat plate.
After applying the load for 12 hours at 40 ℃, remove the load,
The adhesion state of the pellets in the bag was examined. ○ No blocking. △ Some blocking is observed. × Blocking is severe.

The raw materials in the tables used in the examples are as follows. * 1 Chlorinated polyethylene (CPE) manufactured by Showa Denko KK 303B 30% chlorination degree, crystalline 301A 30% chlorination degree, non-crystalline * 2 NBR PNC38 THF insoluble crosslinking component 75 wt% (Nippon Synthetic Rubber Co., Ltd. )) Chemigum P-83 THF insoluble crosslinking component 36 wt%
(Goodyear) PN30A THF insoluble matter 0% (Nippon Synthetic Rubber Co., Ltd.) * 3 Peroxide 2,5-dimethyl-2,5-di (t-butylperoxy) hexane * 4 Acrylic resin P551A Methacryl Methyl acid (70-90wt%)
/ Alkyl acrylate (30 to 10 wt%) (manufactured by Mitsubishi Rayon Co., Ltd.)

Examples 1 to 9 and Comparative Examples 1 to 3 Vinyl chloride resin (PVC, average degree of polymerization 2350), plasticizer and filler in predetermined weight parts (described in Table 1, the same applies hereinafter) and barium-zinc system. 3 parts by weight of the stabilizer was put into a Henschel mixer having a jacket temperature of 100 ° C., and the resin temperature was stirred to 110 ° C. to dry up. After drying up, the temperature of the resin was cooled to 70 ° C. or lower, and then NBR and chlorinated polyethylene (CPE) each containing 75% or 36% of a THF-insoluble cross-linking component were added in predetermined parts by weight and stirred. This was kneaded with a Banbury mixer having a jacket temperature of 130 ° C. until the resin temperature reached 170 ° C., transferred to a mill roll having a surface temperature of 160 ° C., formed into a sheet, and pelletized by a sheet cutting method. The quality of the obtained vinyl chloride resin elastomer composition was evaluated and shown in Table 1.

[0031]

[Table 1]

From the results shown in Table 1, the elastomer composition of the present invention has excellent low-temperature properties and various physical properties such as compression set and extrusion moldability. The sample without the CPE of Comparative Example 1 has a good compression set, but the low temperature properties are slightly inferior.

Examples 10 to 19 and Comparative Examples 4 to 6 Predetermined parts by weight of PVC (average degree of polymerization 2350) (described in Table 2, the same applies hereinafter), 3 parts by weight of barium-zinc stabilizer, prescribed parts by weight of filler, and 5 parts by weight of zinc oxide is stirred in a Henschel mixer, and a predetermined number of parts by weight of a plasticizer is added to dry up. After dry-up, cool with a cooling mixer, add predetermined parts by weight of NBR, CPE, cross-linking agent and cross-linking auxiliary, knead with a Banbury mixer until the resin temperature reaches 185 ° C., and transfer to a mill roll with a surface temperature of 170 ° C. It was made into a sheet and pelletized by the sheet cutting method. However, only Example 11 was kneaded by the same-direction twin-screw extruder and pelletized as it was. The quality of the obtained vinyl chloride elastomer composition was evaluated and Table 2
I wrote it in.

[0034]

[Table 2]

Examples 20 to 24, Comparative Example 7 In the compositions shown in Table 3, first, vinyl chloride resin, acrylic resin, and plasticizer in predetermined amounts and 3 parts by weight of barium-zinc stabilizer were used at a jacket temperature of 100 ° C. Was put into a Henschel mixer and stirred to a resin temperature of about 110 ° C. to obtain a dry blend product. After cooling the dry blended product to a temperature of 70 ° C. or lower, NBR, chlorinated polyethylene, a filler and a crosslinking agent are added in predetermined amounts and mixed,
Then, using a Banbury mixer with a jacket temperature of 130 ° C., a resin temperature of 170 ° C. (Examples 20 and 21) and 185 ° C.
Kneading was carried out until (Examples 22 to 24). This was transferred to a roll having a surface temperature of 160 ° C. (Examples 20 and 21) and 170 ° C. (Examples 22 to 24) to form a sheet, and pelletized by a sheet cutting method. The quality of the obtained elastomer composition was evaluated and the results are shown in Table 3. Comparative Example 7
It carried out according to Example 20.

[0036]

[Table 3]

From the results shown in Table 3, the following can be understood. When NBR containing no gel component is used, the low temperature flexibility is excellent, but the compression set is inferior, and although the extruded product does not have edge breakage, corrugation is observed on the surface of the molded product.
Those with acrylic resin added have improved extrusion moldability,
Moreover, there is an advantage that other physical properties are not impaired.

[0038]

The vinyl chloride resin elastomer composition of the present invention is a vinyl chloride resin, NB containing a partially crosslinked gel component.
By replacing a part of vinyl chloride resin of elastomer consisting of R and plasticizer with chlorinated polyethylene, low temperature flexibility is improved without deteriorating characteristics such as compression set, moldability, bleeding resistance and blocking resistance. In addition to extrusion molding, it can be used as a raw material for calendering, injection molding, inflation molding, compression molding, etc. Therefore, a molded product of any desired shape can be obtained.

The vinyl chloride resin-based elastomer composition of the present invention is particularly useful for weather strips, glass run channels, packings, gaskets, hoses, sheets, grips, rolls, grommets, duct boots, cushioning materials, etc. for industrial use, automobiles, and building materials. It can be used for a wide range of purposes.

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Claims (12)

[Claims] 1. A vinyl chloride resin 95 to 50 parts by weight and a chlorinated polyethylene 5 to 50 parts by weight, and these resins 100.
A vinyl chloride resin elastomer composition containing 20 to 400 parts by weight of an acrylonitrile-butadiene rubber (hereinafter referred to as NBR) containing a tetrahydrofuran-insoluble crosslinking component and 10 to 300 parts by weight of a plasticizer, based on parts by weight. 2. The vinyl chloride resin elastomer composition according to claim 1, which is an NBR containing 30% by weight or more of an insoluble crosslinking component in tetrahydrofuran. 3. The vinyl chloride resin elastomer composition according to claim 1, which contains 0.05 to 10 parts by weight of a crosslinking agent. 4. The vinyl chloride resin elastomer composition according to claim 3, wherein the crosslinking agent is an organic peroxide. 5. The vinyl chloride resin elastomer composition according to claim 1, which contains 1 to 30 parts by weight of an acrylic resin. 6. The vinyl chloride resin elastomer composition according to claim 1, which contains 10 to 600 parts by weight of a filler. 7. The vinyl chloride resin elastomer composition according to claim 6, wherein the filler is calcium carbonate or clay. 8. A vinyl chloride resin 95 to 50 parts by weight and a chlorinated polyethylene 5 to 50 parts by weight, and a total of 1 of these resins.
20 to 400 parts by weight of NBR containing a cross-linking component insoluble in tetrahydrofuran and plasticizers 10 to 3 with respect to 00 parts by weight
A method for producing a vinyl chloride resin-based elastomer composition, which comprises mixing and kneading a mixture containing 100 parts by weight at a temperature of 100 to 230 ° C. 9. The method for producing a vinyl chloride resin elastomer composition according to claim 8, wherein a filler, an acrylic resin or a crosslinking agent is present during mixing and kneading. 10. The vinyl chloride according to claim 8 or 9, wherein a vinyl chloride resin and a plasticizer or a mixture thereof with an acrylic resin is dry-blended in advance and then mixed and kneaded together with other components. A method for producing a resin-based elastomer composition. 11. 95 to 50 parts by weight of a vinyl chloride resin and 5 to 50 parts by weight of chlorinated polyethylene, 20 to 400 parts by weight of NBR, 10 to 300 parts by weight of a plasticizer and 0 parts by weight of a crosslinking agent based on 100 parts by weight of these resins. A method for producing a vinyl chloride resin-based elastomer composition, which comprises mixing and kneading a mixture containing 0.05 to 10 parts by weight at a temperature of 100 to 230 ° C. to produce a tetrahydrofuran-insoluble crosslinking component in NBR. 12. The method for producing a vinyl chloride resin elastomer composition according to claim 11, wherein a filler or an acrylic resin is allowed to exist during mixing and kneading.