JP2000043155A - Method for manufacturing hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a hose by which it is possible to manufacture a hose which has a high rubber elasticity and is of an intricate sigmoid or L-shape without leaving a flaw on the surface easily and at a high production efficiency. SOLUTION: A rubber composition for a vulcanizable hose containing (A) an enthylene.α-olefin non-conjugated polyene copolymer rubber made up of ethylene, a 3-20C α-olefin and a non-conjugated polyene and (B) a polyolefin resin, is molded into a straight hose. Further the hose is primarily vulcanized at a temperature above the Vicat softening point of (B) the polyolefin resin simultaneously with or after molding and then is crosslinked upto 50-90% of an appropriate crosslinking density. Next a mandrel of an objective shape is introduced into the hollow part of the primarily vulcanized hose or the primarily vulcanized hose is introduced into a mold of an objective shape, and further is secondarily vulcanized at a temperature above the Vicat softening point of (B) the polyolefin resin and crosslinked upto the appropriate crosslinking density.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vulcanizable hose rubber composition containing an ethylene / α-olefin / non-conjugated polyene copolymer rubber and a polyolefin resin, which is vulcanized in two steps to produce a hose. The present invention relates to a method for manufacturing a hose.

[0002]

2. Description of the Related Art A radiator hose for cooling an engine, a drain hose for radiator overflow, a heater hose for indoor heating, an air-conditioner drain hose, a wiper water supply hose are used for automobiles, industrial machines, construction machines, motorbikes, agricultural machines, and the like. Various hoses such as a roof drain hose and a protection hose are installed. As a raw material for these hoses, a rubber composition mainly containing an ethylene-propylene-diene copolymer (EPDM) having good ozone resistance, weather resistance and heat resistance is used.

[0003] The above-mentioned hose has a three-dimensional structure of S-shape or L-shape, or a combination of S-shape and L-shape,
In addition, since it has a wide mouth shape and a complicated shape, in general, an unvulcanized rubber is formed into a single-layer or a three-layer hose containing a blade with an extruder, and then a mandrel (circle) having a desired shape is formed. A rod is inserted into a hollow portion of a hose, and vulcanization and shaping (shape shaping) are simultaneously performed in a steam can or an air heating tank. However, in such a manufacturing method, since the hose molded product into which the mandrel imparting the shape is inserted is unvulcanized, surface scratches and crushing of the end portion occur at the time of insertion, and uneven wall thickness occurs. There are many product defects.

As an improved method, a method of vulcanizing a hose after extrusion molding, inserting a mandrel into the vulcanized hose, and reheating to give a shape is considered. However, the conventionally used EPDM cannot be shaped after vulcanization. As a method of giving shape after vulcanization,
A method of adding polyethylene to EPDM is known, but this method has a form in which polyethylene is compatible with EPDM, rubber elasticity is greatly impaired by the influence of polyethylene crystals, and there are problems such as poor sealing properties. .

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a hose having a high rubber elasticity and having a complicated shape such as an S-shape or an L-shape without easily damaging the surface thereof. An object of the present invention is to propose a method of manufacturing a hose that can be manufactured with high production efficiency.

[0006]

The present invention relates to the following method for manufacturing a hose. (1) Vulcanizable containing ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) comprising ethylene, α-olefin having 3 to 20 carbon atoms and non-conjugated polyene and polyolefin resin (B) The rubber composition for hoses is molded into a straight hose, and simultaneously or after this molding, primary vulcanization is performed at a temperature equal to or higher than the Vicat softening point of the polyolefin resin (B) to obtain 50 to 90% of an appropriate crosslink density. And then insert the mandrel of the desired shape into the hollow part of the primary vulcanized hose, or insert the hose of the primary vulcanization into the mold of the desired shape, then the Vicat softening point of the polyolefin resin (B) A method for producing a hose which is subjected to secondary vulcanization at the above temperature to crosslink to an appropriate crosslink density. (2) The method according to (1), wherein the hose retains its shape even after the mandrel or the mold is removed. (3) The rubber composition for a hose as described in (1) above, wherein the rubber composition contains 3 to 50 parts by weight of the polyolefin resin (B) based on 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A). (2) The production method according to the above. (4) The method according to any one of the above (1) to (3), wherein the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) is an ethylene / propylene / non-conjugated diene copolymer rubber. . (5) The polyolefin resin (B) has a Vicat softening point of 1
The method according to any one of the above (1) to (4), which is a polyolefin resin having a temperature of 10 ° C. or higher. (6) The method according to any one of the above (1) to (5), wherein the polyolefin resin (B) is polypropylene. (7) The rubber composition for a hose is a polyamide fiber (C),
The production method according to any one of the above (1) to (6), which comprises the carbon black (D) or the softener (E).

The ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) used in the present invention is obtained by random copolymerizing ethylene, an α-olefin having 3 to 20 carbon atoms, and a non-conjugated polyene. The resulting ethylene / α-olefin / non-conjugated polyene copolymer rubber.

The α-olefin is an α-olefin having 3 to 20 carbon atoms.
-Olefins, among them propylene, 1-butene,
Α-olefins having 3 to 10 carbon atoms such as 4-methyl-1-pentene, 1-hexene and 1-octene are preferred, and propylene and 1-butene are particularly preferred. That is, in the present invention, an ethylene / propylene / non-conjugated polyene copolymer rubber or an ethylene / 1-butene / non-conjugated polyene copolymer rubber is preferably used.

The ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) used in the present invention has a molar ratio of ethylene / α-olefin (ethylene / α-olefin) of 60/40 to 85/15. , Preferably 65/35
Those in the range of ~ 80/20 are desirable.

As the non-conjugated polyene, a cyclic or chain non-conjugated polyene is used. Examples of the cyclic non-conjugated polyene include 5-ethylidene-2-norbornene, dicyclopentadiene, 5-vinyl-2-norbornene, norbornadiene, and methyltetrahydroindene. Examples of the chain non-conjugated polyene include 1,4-hexadiene, 7-methyl-1,
6-octadiene, 8-methyl-4-ethylidene-1,
Examples thereof include 7-nonadiene and 4-ethylidene-1,7-undecadiene. These non-conjugated polyenes are used alone or in combination of two or more, and the copolymerization amount thereof is
It is desirable that the iodine value is 1 to 40, preferably 2 to 35, more preferably 3 to 30.

The intrinsic viscosity [η] of the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) measured at 135 ° C. in decalin (decahydronaphthalene) used in the present invention is 0.8 to 4 dl / g. , Preferably 1 to 3.5 d
1 / g, more preferably in the range of 1.1 to 3 dl / g. The ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) may be a modified product obtained by graft copolymerization of an unsaturated carboxylic acid or a derivative thereof, for example, an acid anhydride. Examples of the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) include ethylene
Most preferred is a propylene / non-conjugated diene copolymer rubber.

The ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) can be used alone or in combination of two or more. The ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) having the above properties is described in “Polymer Production Process (published by the Industrial Research Institute, Inc., pp. 309-33).
0) "and the like.

The polyolefin resin (B) used in the present invention is compounded as a shape-imparting resin.
A crystalline resin or an amorphous resin may be used as long as the resin contains α-olefin as a main component, but a crystalline resin is preferable. The crystalline resin used as the polyolefin resin (B) in the present invention has 2 carbon atoms.
And α-12 homopolymers or copolymers.

This polymerization mode may be any of random polymerization and block polymerization. In the case of a random copolymer, an α-olefin copolymer containing the smaller α-olefin structural unit in an amount of usually 40 mol% or less, preferably 30 mol% or less is desirable. Examples of the α-olefin having 2 to 12 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene.

As the crystalline polyolefin resin (B), polypropylene and polybutene are preferred. Specifically, a propylene homopolymer, a copolymer of propylene and one or more α-olefins having 2 to 12 carbon atoms, a 1-butene homopolymer, and a 1-butene and one or more carbon atoms of 2 Copolymers with α-olefins of from 1 to 12 are preferred. In the case of a copolymer, the content of the α-olefin copolymerized with propylene or 1-butene is desirably 40 to 15 mol%, preferably 35 to 20 mol%.

The amorphous resin used as the polyolefin resin (B) in the present invention includes, for example, an ethylene / cyclic olefin copolymer.

The polyolefin resin (B) used in the present invention has a Vicat softening point (temperature) measured by ASTM D1525 of 110 ° C. or higher, preferably 114 ° C. or higher, more preferably 114 to 160 ° C. When the Vicat softening point of the polyolefin resin (B) is in the above range, a hose having particularly excellent shape stability can be obtained. The polyolefin resin (B) can be used alone or in combination of two or more.

In the vulcanizable hose rubber composition used in the present invention, the particles of the polyolefin resin (B) are micro-dispersed in the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A). The average dispersed particle diameter is usually 0.1 to 200 μm, preferably 0.1 to 10 μm.
It is desirable that the thickness be in the range of 0 μm, more preferably in the range of 0.1 to 50 μm. The average dispersed particle diameter can be determined from a photograph obtained by staining a section of the elastomer with a heavy metal and photographing the section with an electron microscope such as a transmission electron microscope.

In the vulcanizable hose rubber composition used in the present invention, the polyolefin resin (B) is ethylene
Affinity with α-olefin / non-conjugated polyene copolymer rubber (A) is too good.
When the olefin / non-conjugated polyene copolymer rubber (A) and the polyolefin resin (B) are compatible at the molecular level, there is a tendency that the rubber elasticity of the obtained hose is reduced, resulting in a disadvantage. Therefore, the type of the polyolefin resin (B) and the type of the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) must be selected within a range in which both are not compatible at the molecular level.

The aspect ratio (major axis / minor axis) of the dispersed particles of the polyolefin resin (B) is 5 or less, preferably 1 or less.
It is desirably 3. When the aspect ratio is 5 or less, the microdispersion of the polyolefin resin (B) particles is good.

The content ratio of each component of the rubber composition for hoses used in the present invention is 3 to 50 parts by weight of the polyolefin resin (B) per 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A). Parts by weight, preferably 5-4
It is preferably 0 parts by weight, more preferably 5 to 30 parts by weight. In the case of such a content ratio, a hose having an excellent balance between heat recovery and rubber elasticity can be obtained.

The hose rubber composition used in the present invention may contain polyamide fibers (C). As the polyamide fiber (C), an amide group (-CON
Fibers made of polyamide having H-) can be used without limitation. Specific examples include fibers made from polyamide 6 (nylon 6), polyamide 66 (nylon 66), polyamide 11 (nylon 11), polyamide 12 (nylon 12), polyamide 610 (nylon 610), and the like. . The fibers may be short fibers or long fibers, but short fibers are preferred. The polyamide fibers (C) can be used alone or in combination of two or more.

By blending the polyamide fiber (C), deformation due to tensile stress can be reduced, and thereby deformation due to internal pressure of the hose can be suppressed. The amount of the polyamide fiber (C) is ethylene-α-
Olefin / non-conjugated polyene copolymer rubber (A) 100
It is desirable that the amount be 20 parts by weight or less, preferably 3 to 20 parts by weight, more preferably 3 to 10 parts by weight with respect to parts by weight.

The rubber composition for a hose used in the present invention may contain carbon black (D) or a softener (E). As carbon black (D), S
RF, GPF, FEF, MAF, ISAF, SAF, F
Various carbon blacks such as T and MT can be used without limitation. By blending carbon black (D), a hose having excellent tensile strength and elasticity can be obtained. The amount of carbon black (D)
It is desirably 300 parts by weight or less, preferably 80 to 200 parts by weight, per 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A).

As the softener (E), a softener usually used for rubber can be used. For example, petroleum softening agents such as process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, petrolatum; coal tar softening agents such as coal tar and coal tar pitch; castor oil, rapeseed oil, soybean oil, coconut oil, etc. Tallow oil; waxes such as beeswax, carnauba wax and lanolin; ricinoleic acid, palmitic acid, stearic acid,
Fatty acids such as barium stearate and calcium stearate or metal salts thereof; naphthenic acid or metal soaps thereof; pine oil, rosin or derivatives thereof; synthetic polymer substances such as terpene resin, petroleum resin, cumarone indene resin, atactic polypropylene; Ester plasticizers such as dioctyl phthalate, dioctyl adipate and dioctyl sebacate; carbonic ester plasticizers such as diisododecyl carbonate; other microcrystalline wax, sub (factice), liquid polybutadiene, modified liquid polybutadiene, liquid thiocol, hydrocarbon Synthetic lubricating oils and the like.

The amount of the softener (E) is ethylene / α-
Olefin / non-conjugated polyene copolymer rubber (A) 100
200 parts by weight or less, preferably 50 to 1 part by weight
It is desirable to use 50 parts by weight. The polyamide fiber (C), the carbon black (D) and the softener (E) can be blended in all three types, or can be blended in one or two types.

The rubber composition for hoses used in the present invention contains, in addition to the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) and the polyolefin resin (B),
A rubber other than the component (A) can be blended within a range not to impair the object of the present invention. Examples of such other rubbers include natural rubber, styrene / butadiene rubber, nitrile rubber, chloroprene rubber, acrylic rubber, hydrogenated NBR, and the like.

The rubber composition for a hose used in the present invention comprises a vulcanized composition containing at least a vulcanizing agent in addition to the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) and the polyolefin resin (B). A possible rubber composition. In addition to the vulcanizing agent, if necessary, other components such as vulcanization accelerators, vulcanization aids, reinforcing materials, fillers, processing aids, pigments, antioxidants, and foaming agents The compounding agents used in the production may be compounded within a range that does not impair the object of the present invention.

Examples of the vulcanizing agent include sulfur compounds and organic peroxides. Examples of the sulfur compound include sulfur, sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, selenium dithiocarbamate and the like. Of these, sulfur is preferred. Sulfur compounds are ethylene
-Olefin / non-conjugated polyene copolymer rubber (A) 10
It is generally desirable to use 0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight, and more preferably 0.5 to 3 parts by weight with respect to 0 parts by weight.

As the organic peroxide, dicumyl peroxy is used.
Sid, 2,5-dimethyl-2,5-di (t-butylper
Oxy) hexane, 2,5-dimethyl-2,5-di (be
Nzoyl peroxy) hexane, 2,5-dimethyl-
2,5-di (t-butylperoxy) hexyne-3, di
-T-butyl peroxide, di-t-butylperoxy
-3,3,5-trimethylcyclohexane, t-dibutyl
And the like. Among these
Is dicumyl peroxide, di-t-butylperoxy
, Di-t-butylperoxy-3,3,5-trimethyl
Rucyclohexane is preferred. Organic peroxide is ethyl
・ Α-olefin ・ non-conjugated polyene copolymer rubber
(A) For 100 g, usually 3 × 10^-3~ 5 × 10^-2
Mol, preferably 1 × 10 ^-3~ 3 × 10^-2In mole proportion
Used.

When a sulfur compound is used as a vulcanizing agent, it is preferable to use a vulcanization accelerator in combination. Examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazolesulfenamide, N-oxydiethylene-2-
Benzothiazolesulfenamide, N, N'-diisopropyl-2-benzothiazolesulfenamide, 2
-Mercaptobenzothiazole, 2- (2,4-dinitrophenyl) mercaptobenzothiazole, 2- (2,2
6-diethyl-4-morpholinothio) thiazole compounds such as benzothiazole and dibenzothiazyl-disulfide; guanidine compounds such as diphenylguanidine, triphenylguanidine and diorthotolylguanidine; acetaldehyde-aniline condensate, butyraldehyde- Aldehyde amine compounds such as aniline condensates;
Imidazoline compounds such as 2-mercaptoimidazoline; thiourea compounds such as diethylthiourea and dibutylthiourea; thiuram compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate and diethyldithiocarbamate Dithionate compounds such as tellurium; xanthate compounds such as zinc dibutylxanthogenate; and zinc white. These vulcanization accelerators are ethylene α
-Olefin / non-conjugated polyene copolymer rubber (A) 10
0.1 to 20 parts by weight relative to 0 parts by weight, preferably 0.1 to 20 parts by weight.
It is desirable to use 2 to 10 parts by weight, more preferably 0.5 to 5 parts by weight.

When an organic peroxide is used as a vulcanizing agent, it is preferable to use a vulcanizing aid in combination. Examples of the vulcanization aid include sulfur; quinone dioximes such as p-quinone dioxime; (meth) acrylic compounds such as ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate; diallyl phthalate, triallyl isocyanurate and the like. Allyl compound; other maleimide compounds, divinylbenzene (DVB), and the like.
It is desirable that such a vulcanization aid be used in a proportion of 0.5 to 2 mol, preferably equivalent mol, per mol of the organic peroxide used.

As the reinforcing material, for example, finely divided silica is appropriately used. As the filler, for example, light calcium carbonate, heavy calcium carbonate, talc, clay and the like are used. These reinforcing materials and fillers are usually 200 parts by weight or less based on 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A).
Preferably, it is used in a proportion of 150 parts by weight or less.

As processing aids, processing aids used in ordinary rubber processing can be used. Examples of such processing aids include higher fatty acids such as ricinoleic acid, stearic acid, palmitic acid, and lauric acid; higher fatty acid salts such as barium stearate, calcium stearate, and zinc stearate; ricinoleate, stearic acid ester, And higher fatty acid esters such as palmitic acid esters and lauric acid esters.
These processing aids are based on 100 parts by weight of ethylene / α-olefin / non-conjugated polyene copolymer rubber (A).
Usually, it is desirable to use it in a proportion of about 10 parts by weight or less, preferably about 1 to 5 parts by weight.

As the pigment, known inorganic pigments (for example, titanium white) and organic pigments (for example, naphthol green B) can be used. These pigments are ethylene / α-olefin / non-conjugated polyene copolymer rubber (A)
It is desirable to use up to 20 parts by weight, preferably up to 10 parts by weight, per 100 parts by weight.

Examples of the antioxidant include aromatic secondary amine stabilizers such as phenylbutylamine and N, N'-di-2-naphthyl-p-phenylenediamine; dibutylhydroxytoluene, tetrakis [methylene (3,5 −
Phenolic stabilizers such as di-t-butyl-4-hydroxy) hydrocinnamate] methane; bis [2-methyl-4- (3-n-alkylthiopropionyloxy)-
Thioether stabilizers such as [5-t-butylphenyl] sulfide; dithiocarbamate stabilizers such as nickel dibutyldithiocarbamate;

These antioxidants can be used alone or in combination of two or more. Such an antioxidant is generally used in an amount of 0.1 to 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A).
It is desirable to use 5 parts by weight, preferably 0.5 to 3 parts by weight. The hose made of the rubber composition for a hose used in the present invention has excellent heat resistance and durability even without using an anti-aging agent, but the use of the anti-aging agent can prolong the product life. Is possible.

The rubber composition for a hose used in the present invention can be produced by micro-dispersing particles of a polyolefin resin (B) in an ethylene / α-olefin / non-conjugated polyene copolymer rubber (A). . In order to micro-disperse the particles of the polyolefin resin (B), 1) the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) and the polyolefin resin (B) are mixed and kneaded in a molten state to obtain a polyolefin resin. (B) a method of imparting a shearing action (shearing force); 2) adding a polyolefin resin (B) to a rubber mixture comprising an ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) and an organic solvent; Kneading the rubber mixture and the polyolefin resin (B),
A method of removing the solvent and the like can be mentioned. According to such a method, the morphology (phase morphology) in which the polyolefin resin (B) is micro-dispersed in the rubber composition for a hose.
Can be achieved, but when the temperature during kneading is low or the shearing energy is insufficient, the polyolefin resin (B)
When the average dispersed particle size of the polyolefin resin (B) exceeds 200 μm, the strength of the obtained hose is reduced, or the flowability of the polyolefin resin (B) is reduced, It tends to impair workability.

The rubber composition for a hose used in the present invention is preferably prepared by a kneading apparatus capable of giving a high shearing force. Specifically, the mixing can be carried out using a kneading device such as a mixing roll, an intensive mixer (for example, a Banbury mixer, a kneader, etc.), a single-screw or twin-screw extruder. Preferably, a composition is prepared. By kneading with a twin-screw extruder, a rubber composition for hoses in which the polyolefin resin (B) is dispersed at the average dispersed particle diameter can be easily prepared.

When other components such as polyamide fiber (C), carbon black (D), softener (E) and other additives are added to the rubber composition for a hose used in the present invention, ethylene is added by the above-mentioned method. After preparing a rubber composition in which the polyolefin resin (B) is micro-dispersed in the α-olefin / non-conjugated polyene copolymer rubber (A), other components are added to the rubber composition and kneaded. It is preferable to prepare a rubber composition for hoses containing the following components. The other components can be compounded using a kneading device such as a mixing roll, an intensive mixer (for example, a Banbury mixer, a kneader, etc.), a single-screw or twin-screw extruder.

As the method 1), the following method is specifically exemplified. That is, the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) and the polyolefin resin (B) are 200-350 with a twin-screw extruder.
Mix and knead at a temperature of 0.5 to 1.5 minutes. At this time, when the polyolefin resin (B) is a propylene homopolymer (B), the specific energy of the propylene homopolymer (B) is set to 0.01 in a twin-screw extruder at a temperature of 200 ° C.
kW · hr / kg or more, preferably 0.02 kW · hr
/ Kg or more is desirably kneaded in a molten state.

Next, the obtained kneaded material and other components such as polyamide fiber (C), carbon black (D), softener (E) and other additives are mixed using a mixer such as a Banbury mixer. And knead at 80-170 ° C. for 3-10 minutes. Next, a vulcanizing agent, a vulcanization aid, and the like are additionally mixed with the obtained kneaded material using rolls such as an open roll, and kneaded at a roll temperature of 40 to 80 ° C. for 3 to 30 minutes to dispense. A ribbon-shaped or sheet-shaped rubber composition for hose (unvulcanized rubber compound) used in the present invention is prepared. When blending polyamide fiber (C), polyamide fiber (C)
Is preferably previously mixed with the component (A) or a mixture of the components (A) and (B). When mixing with the component (A), the mixing ratio of the premix is (A) component /
The weight ratio of the component (C) is desirably 100 / (5 to 100), preferably 100 / (10 to 70). When mixed with a mixture of the component (A) and the component (B), the weight ratio of the component (A) / the component (B) / the component (C) is 1
00 / (5-50) / (5-200), preferably 10
0 / (20-40) / (80-110) is desirable.

As the method 2), the following method is specifically exemplified. That is, a rubber mixture comprising 100 parts by weight of an ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) and 3 to 10 parts by weight of an organic solvent is introduced into the extruder from a supply section of a multi-stage vented extruder. Then, the polyolefin resin (B) is introduced into the extruder from another supply section under an inert gas atmosphere, and the rubber mixture and the polyolefin resin (B) are kneaded and desolventized.
Thereafter, other components such as polyamide fiber (C), carbon black (D), softener (E) and other additives are kneaded by the same method as exemplified in the above 1), and then the vulcanizing agent is added. , A vulcanization aid and the like are kneaded to prepare a rubber composition for a hose used in the present invention.

In the present invention, a hose is produced by vulcanizing a hose-like molded article comprising the above vulcanizable rubber composition for a hose in two stages. That is, the vulcanizable hose rubber composition is molded into a straight hose by a known molding method such as extrusion molding, and simultaneously with or after this molding, the Vicat softening point of the polyolefin resin (B) in the rubber composition. Primary vulcanization is performed at the above temperature. In the primary vulcanization, crosslinking is performed to 50 to 90%, preferably 60 to 80% of the appropriate crosslinking density.

Next, after inserting the mandrel having the desired shape into the hollow portion of the primary vulcanized hose, or after inserting the primary vulcanized hose into the mold having the desired shape, the Vicat softening point of the polyolefin resin (B) is exceeded. Secondary vulcanization at a temperature of In this secondary vulcanization, crosslinking is performed to an appropriate crosslinking density, that is, 100%. After the secondary vulcanization, the hose having the desired shape can be obtained by cooling to a temperature lower than the Vicat softening point of the polyolefin resin (B). The hose thus obtained retains the shape imparted by the mandrel or mold even after the mandrel or mold has been removed from the hose. The hose deforms when a force is applied, but returns to its original shape when the force is removed.

Here, the term "appropriate crosslinking density" refers to the crosslinking density at which the rubber composition for a hose exhibits 100% of the performance as a vulcanized rubber. The time [tc (90), the unit is minutes] of 90% of the maximum torque when the vulcanization curve of the rubber composition for rubber was measured, was defined as follows based on this tc (90). Crosslink density. The crosslink density is F
It can be measured using toluene at 37 ° C. according to the low-Rehner equation.

Proper crosslink density (pieces / ml) = crosslink density when crosslinked at a proper crosslink time (pieces / ml) Proper crosslink time (min) = tc (90) (min) + (BA)
× 1 (min) + C (min) [where A is the average thickness (unit: mm) of the sample used for measuring the vulcanization curve for obtaining tc (90), and B is the average of the hose used for primary crosslinking. The thickness (unit: mm). C is a coefficient, and 10 when the actual crosslinking temperature is 160 ° C.
It is 6 at 170 ° C. and 3 at 180 ° C. ]

As the shape of the mandrel or mold used for manufacturing the hose, any shape can be used depending on the shape of the target hose. For example, not only a rod-shaped (straight) shape but also an S-shape or a shape can be used. It is also possible to use an L-shape or a complicated shape obtained by combining them. Even when a mandrel with a complicated shape is used, the hose is vulcanized to 50 to 90% of the appropriate crosslink density in the primary vulcanization, so that the surface of the hose when the mandrel is inserted or when it is inserted into a mold is used. Scratches, crushing of the ends and uneven thickness are prevented. Then, after inserting the mandrel of the target shape or after inserting it into the mold, it is vulcanized to the appropriate crosslink density by secondary vulcanization, so that finally the appropriate rigidity, flexibility and mechanical strength as a hose Is obtained.

Specifically, the following method is exemplified. That is, the rubber composition for a hose is molded into a hose or a tube having a hollow portion by an extruder, a press, or the like at a temperature lower than the Vicat softening point of the polyolefin resin (B), and the molded body is vulcanized simultaneously with the molding. In the tank,
The primary vulcanization is carried out by heating at a temperature not lower than the Vicat softening point of the polyolefin resin (B), usually at 150 to 250 ° C. for about 60 seconds to 3 minutes. Examples of the vulcanizing tank include a steam vulcan, a hot air vulcanizing tank, a fluidized bed of glass beads, a molten salt vulcanizing tank, a microwave tank, a press, an injection molding machine, and a transfer molding machine. These vulcanizing tanks are used alone or in combination.

Next, a mandrel having a desired shape is inserted into the hollow portion of the primary vulcanized rubber hose obtained as described above, or
Or insert the primary vulcanized rubber hose into the mold of the desired shape,
Thereafter, after being placed in an atmosphere having a temperature equal to or higher than the Vicat softening point of the polyolefin resin (B), the final shape is formed at a temperature equal to or higher than the Vicat softening point of the polyolefin resin (B), and then cooled to a temperature lower than the Vicat softening point. The cooling method is not particularly limited, such as natural cooling, water cooling, or air cooling.

According to the hose manufacturing method of the present invention as described above, after the mandrel is inserted into the incompletely crosslinked hose after the primary vulcanization, secondary vulcanization is performed to perform complete crosslinking and final shaping. As a result, it is possible to prevent surface scratches and end crushing when inserting the mandrel, reduce the occurrence of defective products, and easily and efficiently manufacture hoses with complicated shapes. it can.

In the production method of the present invention, the polyolefin resin (B) is used as a rubber composition for a hose.
-When a composition micro-dispersed in the olefin / non-conjugated polyene copolymer rubber (A) is used, a hose having more excellent rubber elasticity can be obtained.

The hose obtained by the production method of the present invention can be suitably used as a hose or tube for automobiles, construction machines, industrial machines, motorbikes, agricultural machines, general industries, and the like. Specifically, it is preferably used as various hoses such as a radiator hose for cooling an engine, a radiator overflow drain hose, an indoor heating heater hose, an air conditioner drain hose, a wiper water supply hose, a roof drain hose, and a protect hose. Can be.

[0054]

According to the method for producing a hose of the present invention, an ethylene / α-olefin / non-conjugated polyene copolymer rubber (A)
And a vulcanizable rubber composition for a hose containing the polyolefin resin (B) are molded into a straight hose, and simultaneously or after the primary vulcanization at a temperature equal to or higher than the Vicat softening point of the polyolefin resin (B). And an appropriate crosslink density of 50
After cross-linking to ~ 90%, then insert the mandrel of the desired shape into the hollow portion of the primary vulcanized hose, or insert the hose of the primary vulcanization into the mold of the target shape, and then use the polyolefin resin (B). Secondary vulcanization at a temperature equal to or higher than the Vicat softening point and cross-linking to an appropriate cross-link density, so that hoses with high rubber elasticity and complicated shapes such as S-shape and L-shape are scratched on the surface. It can be manufactured easily and with high production efficiency.

[0055]

Next, an embodiment of the present invention will be described. The materials used and the measuring method in each example and comparative example are as follows.

<< Materials Used >> EPDM: Mitsui Chemicals, Inc. Mitsui EPT-3090E
(Trademark), ethylene propylene 5-ethylidene-2
-Norbornene copolymer, paraffinic oil 10 parts by weight oil extended, ethylene / propylene (molar ratio) = 68/3
2, iodine value = 12, ethylene / propylene / 5-ethylidene-2-norbornene (weight ratio) = 58 / 37.7
/4.3, intrinsic viscosity (decalin 100 ° C) = 2.80d
l / g, component (A) ・ Polypropylene: J-30 manufactured by Grand Polymer Co., Ltd.
0 (trademark), Vicat softening point = 150 ° C, component (B) ・ Zinc flower: 2 types manufactured by Sakai Chemical Co., Ltd. ・ Stearic acid: manufactured by Kao Corporation ・ FEF carbon black: Show black manufactured by Showa Cabot Co., Ltd. N-550 (trademark)-Paraffin oil: Diana Process Oil PW-90 (trademark) manufactured by Idemitsu Kosan Co., Ltd.-Nylon 6 short fiber: EPDM nylon 6 short fiber made by Ube Industries, Ltd.-Defoaming agent: Inoue Vesta PP (trademark) manufactured by Lime Co., Ltd.-Vulcanization accelerator CBS: Suncellar CM (trademark) manufactured by Sanshin Chemical Industry Co., Ltd.-Vulcanization accelerator ZnBDC: Suncellar BZ (trademark) manufactured by Sanshin Chemical Industry Co., Ltd. -Vulcanization accelerator TMTD: Suncellar TT (trademark) manufactured by Sanshin Chemical Industry Co., Ltd.-Vulcanization accelerator EU: Suncellar 2 manufactured by Sanshin Chemical Industry Co., Ltd.
2 (trademark)-Vulcanization accelerator TeEDC: Suncellar TE (trademark) manufactured by Sanshin Chemical Industry Co., Ltd.-Morpholine vulcanizing agent: Sanfel R (trademark) manufactured by Sanshin Chemical Industry Co., Ltd.-Sulfur

<< Sample preparation >> (1) Preparation of EPDM containing shape-imparting resin The above-mentioned EPDM and polypropylene were used as the shape-imparting resin in a 1.7 liter Mixtron mixer manufactured by Kobe Steel Ltd. ° C
The mixture was kneaded at a high temperature for about 5 minutes, and the polypropylene was uniformly microdispersed in EPDM. After discharging from the mixer, the mixture is naturally cooled, and the EPDM containing the shape-imparting resin
I got (2) Preparation of Rubber Composition for Hose (1) EPDM containing shape-imparting resin obtained in (1) above, 2 kinds of zinc white, stearic acid, FEF in a 1.7 liter Mixtron mixer manufactured by Kobe Steel, Ltd. Carbon black and paraffin oil were added and kneaded for about 7 minutes. Then, after discharging from the mixer, the mixture was naturally cooled. The temperature of the kneaded material immediately after being discharged from the mixer was 170 ° C. Thereafter, the defoaming agent, vulcanization accelerator, morpholine vulcanizing agent and sulfur were kneaded with the kneaded product using an 8-inch open roll to obtain a vulcanizable hose rubber composition (1). (3) Preparation of Rubber Composition for Hose (2) EPDM containing shape-imparting resin obtained in (1) above, 1.7 kinds of zinc white, stearic acid, FEF in a 1.7 liter Mixtron mixer manufactured by Kobe Steel, Ltd. Carbon black, paraffinic oil and nylon 6 single fiber were added and kneaded for about 7 minutes. Thereafter, a vulcanizable hose rubber composition (2) was obtained in the same manner as in the above (2).

(4) Preparation of vulcanization of sample for physical property test A sample for tensile test and hardness test (thickness 2 mm, length 12
A 5 mm, 140 mm wide sheet) and a sample for a compression set test (a cylindrical molded product having an outer diameter of 29 mm and a height of 12.5 mm) were vulcanized under the following conditions. Sample for tensile test and hardness test: 180 ° C, 7 minutes Sample for compression set test: 180 ° C, 10 minutes

(5) Preparation of Samples for Shape Rate Test and Crosslink Density Test Using the rubber composition for hose (1) or (2) obtained in the above (2) or (3), a 50 mm extruder ( Head / cylinder 1 / cylinder 2 / screw temperature = 60 ° C / 50 ° C / 40 ° C / 40 ° C,
A hose having an outer diameter of 13 mm and an inner diameter of 10 mm was extruded.
Immediately after molding, the temperature in the tank is set to 230 ° C and primary vulcanization is performed for the following time so that the temperature of the hose becomes 180 ° C in the hot air vulcanizing tank, and the primary vulcanization is performed for the shaping rate test and the crosslink density test. A vulcanized hose was made. 7.5 minutes (vulcanization time for crosslinking to an appropriate crosslinking density,
6 minutes (80% of proper vulcanization time) 5 minutes (67% of proper vulcanization time)

(6) Proper Crosslink Density The proper crosslink density is determined by measuring the vulcanization curve of the rubber composition at the actual crosslink temperature of the rubber product with a vibration type vulcanizing tester at 90% of the maximum torque when the vulcanization curve is measured. tc (90)
The unit is minute], and based on this tc (90), the following equation was used.

Proper crosslink density (pieces / ml) = crosslink density when crosslinked at a proper crosslink time (pieces / ml) Proper crosslink time (min) = tc (90) (min) + (BA)
× 1 (min) + C (min) [where A is the average thickness of the sample in the vulcanization test (unit is m
m) and B are the thickness (unit: mm) of the hose to be crosslinked. C is a coefficient, and is 10 when the actual crosslinking temperature is 160 ° C., 6 when it is 170 ° C., and 3 when it is 180 ° C. ]

<< Measurement Method >> (1) Vulcanization Test Vibration type vulcanization tester (Mo) according to JIS K-6300
nsanto MDR) at 180 ° C.
c (90) was determined. (2) Crosslink density The crosslink density was measured at 37 ° C. from toluene according to the Flory-Rehner equation.

(3) Shaping rate Hose made of a rubber composition not containing a shape-shaping resin a) An uncured hose having an outer diameter of 13 mm and an inner diameter of 10 mm formed by an extruder was replaced with an L-shaped hose having an outer diameter of 10.1 mm. It was inserted into a mold mandrel and the interior angle (C ₁ ) was measured. b) Next, vulcanization is performed for 7.5 minutes in a hot air vulcanization tank at 230 ° C. where the hose temperature becomes 180 ° C. to crosslink to an appropriate crosslink density,
The mandrel was immediately removed from the hose. c) The hose was left at room temperature (25 ° C.) for one day, and the inner angle (C ₂ ) of the hose was measured. Hose made of rubber composition for shape-forming resin-containing hose a) Insert a primary cross-linked hose having an outer diameter of 13 mm and an inner diameter of 10 mm into an L-shaped mandrel having an outer diameter of 10.1 mm,
The internal angle (C ₁ ) was measured. b) Next, after being left in an oven at 180 ° C. for 5 minutes, it was cooled with water for 5 minutes. c) The mandrel was removed from the hose and left at room temperature (25 ° C.) for one day, and the inner angle (C ₂ ) of the hose was measured. Calculation of the shaping rate The shaping rate is the interior angle (unit: degree) measured above or above
From the following equation. Shaping rate (%) = [180− (C ₂ )] / [180−
(C ₁ )] × 100

<< Physical Property Test >> (1) Measurement Room Conditions The measurement was performed according to JIS K-6250. (2) Tensile test According to JIS K-6251. (3) Hardness test According to JIS K-6253. (4) Permanent compression set Measured at 120 ° C. for 22 hours according to JIS K-6262.

<<Girl's Handprint When Inserting Mandrel >> a) A surfactant-based external release agent was applied to the mandrel. b) Next, the gloves were worn and the extruded unvulcanized hose or primary vulcanized hose was inserted into the mandrel. c) visually observe the surface of the hose in which the mandrel is inserted,
It was determined whether there was a glove trace.

Example 1 110 parts by weight of Mitsui EPT-3090E and polypropylene J made by Grand Polymer Co., Ltd. as a shape-imparting resin
20 parts by weight of -300 were added to the shape-imparting resin-containing EPDM previously kneaded by the above method, and two kinds of zinc white at the ratio shown in Table 1.
Formulated with stearic acid, FEF carbon black and paraffinic oil, 1.7 liter manufactured by Kobe Steel, Ltd.
The mixture was kneaded by the above method using a Mixtron mixer. After cooling,
A defoaming agent, a vulcanization accelerator,
The morpholine vulcanizing agent and sulfur were kneaded by the above method to obtain a rubber composition for hoses (1). A sample was prepared from a part of this rubber composition by the method described above, and a tensile test, a hardness test and a compression set test were performed. Further, a primary vulcanized hose was prepared from the remainder of the rubber composition by the above-described method, and the crosslink density, the shaping ratio, and the glove marks at the time of inserting the mandrel were examined by the method. The primary vulcanization time was 5 minutes, and the secondary vulcanization time was 8 minutes. Tables 4 and 5 show these results.

Example 2 Example 2 was repeated except that the primary vulcanization time was changed to 6 minutes. The results are shown in Tables 4 and 5.

Example 3 The same procedure as in Example 1 was carried out except that the mixing ratio was changed to the ratio shown in Table 1, and the primary vulcanization time was changed to 6 minutes.
The results are shown in Tables 4 and 5.

Example 4 The same procedure as in Example 1 was carried out except that the mixing ratio was changed to the ratio shown in Table 1, and the primary vulcanization time was changed to 6 minutes.
The results are shown in Tables 4 and 5.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the primary vulcanization time was 7.5 minutes and crosslinking was performed to an appropriate crosslinking density. The results are shown in Tables 6 and 7.

Comparative Example 2 Except that the blending ratio was changed to the ratio shown in Table 2 and that the primary vulcanization time was 7.5 minutes and crosslinking was performed to an appropriate crosslinking density,
Performed in the same manner as in Example 1. The results are shown in Tables 6 and 7.

Comparative Example 3 Except that the mixing ratio was changed to the ratio shown in Table 2 and that the primary vulcanization time was 7.5 minutes and the crosslinking was performed to an appropriate crosslinking density,
Performed in the same manner as in Example 1. The results are shown in Tables 6 and 7.

Comparative Example 4 Two kinds of zinc white, stearic acid, FEF carbon black and paraffin-based oil were mixed with 110 parts by weight of Mitsui EPT-3090E in the ratios shown in Table 3 to obtain a mixture of the following. The mixture was kneaded with a 7 liter mixer mixer for 7 minutes to obtain an EPDM compound containing no shape-imparting resin. The temperature of the kneaded material immediately after being discharged from the mixer was 170 ° C. After cooling, the kneaded product was kneaded with an 8 inch open roll using a defoaming agent, a vulcanization accelerator, a morpholine vulcanizing agent and sulfur in the proportions shown in Table 3 to obtain a rubber composition containing no shape-imparting resin. Was.

A sample was prepared from a part of this rubber composition by the method described above, and a tensile test, a hardness test and a compression set test were performed. A 50 mm extruder (with a vent) was set from the remainder of the rubber composition to a head / cylinder 1 / cylinder 2 / screw temperature = 60 ° C./50° C./40° C./40° C., and a hose having an outer diameter of 13 mm and an inner diameter of 10 mm Was extruded. After cooling, an L-shaped mandrel having an outer diameter of 10.1 mm was inserted in an unvulcanized state, and military hand marks when the mandrel was inserted were examined. Next, after measuring the inner angle of the hose into which the mandrel was inserted, the hose was vulcanized for 7.5 minutes in a hot air vulcanization tank set at 230 ° C. so that the temperature of the hose became 180 ° C. A sulfuric hose was made. The vulcanized hose was immediately removed from the mandrel, and allowed to stand at room temperature for one day, and then the crosslink density and the shaping ratio were determined by the above-described methods. Tables 8 and 9 show these results.

Comparative Example 5 In Example 2, except that the rubber composition not containing a shape-imparting resin of Comparative Example 4 was used instead of the rubber composition for a hose,
Performed in the same manner as in Example 2. The results are shown in Tables 8 and 9.

Comparative Example 6 Example 2 was repeated, except that the rubber composition for a hose of Comparative Example 4 was used instead of the rubber composition for a hose, and the primary vulcanization time was changed to 7.5 minutes. Performed in the same manner as in Example 2. The results are shown in Tables 8 and 9.

[0077]

[Table 1]

[0078]

[Table 2]

[0079]

[Table 3]

[0080]

[Table 4] Note) Vulcanization for 7.5 minutes in primary vulcanization results in an appropriate crosslink density. * 1 Percentage of crosslink density to proper crosslink density

[0081]

[Table 5] Note) Vulcanization for 7.5 minutes for primary vulcanization will result in an appropriate crosslinking density

[0082]

[Table 6] Note) Vulcanization for 7.5 minutes in primary vulcanization results in an appropriate crosslink density. * 1 Percentage of crosslink density to proper crosslink density

[0083]

[Table 7] Note) Vulcanization for 7.5 minutes for primary vulcanization will result in an appropriate crosslinking density

[0084]

[Table 8] Note) Vulcanization for 7.5 minutes in primary vulcanization results in an appropriate crosslink density. * 1 Percentage of crosslink density to proper crosslink density

[0085]

[Table 9] Note) Vulcanization for 7.5 minutes for primary vulcanization will result in an appropriate crosslinking density

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kotaro Ichino 3 Chikusa Beach, Ichihara-shi, Chiba Mitsui Chemicals Co., Ltd. Terms (reference) 3H111 AA02 BA13 BA25 BA28 BA34 CB02 EA04 4F213 AA03 AA09 AA09A AA29 AA46 AB18 AB25 AD12 AG08 AL18 AR06 WA06 WA54 WA72 WA87 WB02 WE16

Claims (7)

[Claims] An ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) comprising ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated polyene, and a polyolefin resin (B). The vulcanizable rubber composition for a hose is molded into a straight hose, and simultaneously with or after this molding, primary vulcanization is performed at a temperature equal to or higher than the Vicat softening point of the polyolefin resin (B). After cross-linking to 90% and then inserting the mandrel of the desired shape into the hollow portion of the hose that has been primary vulcanized, or inserting the hose that has been primarily vulcanized into the mold of the desired shape, the vicat of the polyolefin resin (B) A method for producing a hose that undergoes secondary vulcanization at a temperature equal to or higher than the softening point to crosslink to an appropriate crosslinking density. 2. The method according to claim 1, wherein the hose retains its shape even after the mandrel or the mold is removed. 3. A rubber composition for a hose, comprising ethylene-α-
Olefin / non-conjugated polyene copolymer rubber (A) 100
The method according to claim 1 or 2, wherein the polyolefin resin (B) is contained in an amount of 3 to 50 parts by weight based on part by weight. 4. The method according to claim 1, wherein the ethylene / α-olefin / non-conjugated polyene copolymer rubber (A) is an ethylene / propylene / non-conjugated diene copolymer rubber. 5. The production method according to claim 1, wherein the polyolefin resin (B) is a polyolefin resin having a Vicat softening point of 110 ° C. or higher. 6. The production method according to claim 1, wherein the polyolefin resin (B) is polypropylene. 7. The method according to claim 1, wherein the rubber composition for a hose contains polyamide fiber (C), carbon black (D) or softener (E).