JPH06264308A - Polyester fiber for reinforcing rubber and rubber molding - Google Patents

Abstract

PURPOSE:To obtain a polyester fiber material for reinforcement of rubber products excellent in adhesion to rubber, suppressed in deterioration in being exposed at high temperature for a long time in rubber moldings and used for various severe uses. CONSTITUTION:The polyester fiber material for reinforcement of rubber contains a copolymer of ethylene and monochlorotrifluoroethylene in an amount of >=0.1wt.% and <=10wt.%. The resultant rubber molding is useful as a tire, a belt, hose, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester fiber and a rubber molding which are used as a rubber reinforcing material to suppress deterioration after being embedded in rubber.

[0002]

2. Description of the Related Art Polyester fibers are widely used as a reinforcing material for rubber products such as tires, belts and hoses because they have excellent mechanical strength and low extensibility. But,
When the obtained rubber product is exposed to a high temperature for a long time, the polyester fiber is liable to deteriorate and the initial strength cannot be fully utilized. Therefore, there are many restrictions on the use of polyester fibers in rubber products that are forced to be used at high temperatures. In order to solve this problem, various proposals have been conventionally made. For example, a polyester fiber for rubber reinforcement in which the amount of terminal carboxyl groups contained in polyester is reduced by adding an epoxy compound, an oxazoline compound, a carbodiimide compound, etc., a polyester fiber for rubber reinforcement in which a copper compound is added, and the like. A rubber-reinforcing polyester fiber (Japanese Patent Application Laid-Open No. 55-166235) to which a polymer made of acrylic acid and / or methacrylic acid has been previously proposed is known.

Although the above-mentioned conventional polyester fibers for rubber reinforcement have a tentative effect of suppressing deterioration in rubber, they do not reach a practical level or the effect of suppressing deterioration in rubber is at a practical level. However, there is a problem that the affinity with an adhesive for adhering to rubber is low and the adhesiveness with rubber tends to be poor.

[0004]

The object of the present invention is to provide a rubber-reinforcing polyester fiber which has a good effect of suppressing deterioration in rubber and which can maintain a high affinity with an adhesive for adhering to rubber. There is provided a rubber molding reinforced with the polyester fiber.

[0005]

The object of the present invention is to provide a polyester fiber for rubber reinforcement, characterized in that it contains 0.1% by weight or more and 10% by weight or less of a copolymer of ethylene and monochlorotrifluoroethylene. , And 0.1% of a copolymer of ethylene and monochlorotrifluoroethylene.
This is achieved by a rubber molded body reinforced with polyester fibers containing at least 10% by weight.

The present invention will be described in detail below. The polyester of the present invention is polyethylene terephthalate (hereinafter referred to as P
(Referred to as ET) and polybutylene terephthalate are preferred, and PET is more preferred. Part of the dicarboxylic acid component is isophthalic acid, 2,6-
It may be replaced with naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, dimer acid, sulfonic acid metal salt-substituted isophthalic acid, etc., and a part of the glycol component is diethylene glycol, neopentyl glycol, 1,4. -Cyclohexanediol, 1,4-cyclohexanedimethanol, polyalkylene glycol and the like may be substituted. Furthermore, a small amount of a chain branching agent such as pentaerythritol, trimethylolpropane, trimellitic acid, trimesic acid and boric acid can be used together. In addition, titanium oxide, silicon oxide, calcium carbonate, silicon nitride, clay, talc, kaolin,
Various inorganic particles such as zirconium acid and crosslinked polymer particles,
In addition to particles such as various metal particles, conventionally known antioxidants,
Metal ion sequestering agents, ion exchangers, anti-coloring agents, light stabilizers, flame retardants, inclusion compounds, antistatic agents, various colorants, waxes, silicone oils, various fluorine-based surfactants, various reinforcing fibers, etc. It may be added. Two or more kinds of the above modified polyester resins may be blended with the polyester of the present invention, and further, a polyamide,
Polyester amide, epoxy resin, silicone resin,
It may be a small amount of a blend of a small amount of a polyolefin resin, various rubbers, resins such as polycarbonate, polyurethane and polyacrylate, and various fluororesins other than the copolymer of ethylene and monochlorotrifluoroethylene. Also,
The polyester used in the present invention may be modified with various modifiers, for example, a terminal carboxyl group blocking agent such as a carbodiimide compound, an epoxy compound, an isocyanate compound and an oxazoline compound. The polyester fiber of the present invention may be in any form such as a spun / stretched yarn, a cord formed by twisting a yarn, a woven fabric obtained by weaving the cord.

The intrinsic viscosity of the polyester fiber of the present invention is
Usually, it may be 0.6 or more. Here, the intrinsic viscosity is the intrinsic viscosity obtained from the viscosity measured at 25 ° C. in an orthochlorophenol solution and is represented by [η].

The copolymer of ethylene and monochlorotrifluoroethylene (hereinafter referred to as ECTFE) used in the present invention is a random copolymer of ethylene and monochlorotrifluoroethylene, and the copolymerization ratio is about a molar ratio. It is a 1: 1 copolymer. Also, as ECTFE,
Those having different fluidity (hereinafter referred to as MFR) in a molten state are known, and the ECTFE used in the present invention has an MFR of 1 measured at 271.5 ° C. and a total load of 2160 g according to ASTM D-1238. ~ 35g / 10
Minutes can be used, but MFR is 13 to 32
It is preferable to use g / 10 min because the physical properties of the raw yarn tend to be good.

EC contained in the polyester fiber of the present invention
TFE needs to be 0.1% by weight or more and 10% by weight or less, more preferably 0.3% by weight or more and 8% by weight or less, further preferably 0.4% by weight or more and 7% by weight or less. . If it is less than 0.1% by weight, the effect of suppressing deterioration in rubber is insufficient, and if it is more than 10% by weight, the adhesiveness to rubber is impaired, which is not preferable. The ECTFE and polyester are mixed by a method in which ECTFE is added to the molten polyester immediately after the completion of the polycondensation reaction and kneading, or a method in which ECTFE is added and mixed in the polyester chips and then kneaded in a mixing can or an extruder. It can be carried out.

The polyester fiber of the present invention is a core-sheath composite fiber in which the polyester of the core component contains ECTFE,
Alternatively, core-sheath composite fibers in which the ECTFE contents of polyesters constituting the core and the sheath are different may be used. Further, the polyester fiber of the present invention may be a core-sheath composite fiber in which the ratio of the core component is 50% by weight or more, the polyester containing ECTFE is the core component, and the polyamide is the sheath component.

The rubber-reinforcing polyester fiber of the present invention is effective for a composition comprising various vulcanization accelerators, vulcanization aids such as zinc white and rubber. As a vulcanization accelerator,
For example, N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydiethylene-2-benzothiazole sulfenamide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetramethylthiuram monosulfide, dimethyl. Examples thereof include sodium thiocarbamate, sodium diethylthiocarbamate, zinc dimethylthiocarbamate, zinc diethylthiocarbamate, 2-mercaptobenzothiazole, and dibenzothiazole disulfide. Examples of the rubber include natural rubber, styrene-butadiene rubber, isoprene-based rubber, chloroprene-based rubber, ethylene-propylene-based rubber, and the like, and a combination of a plurality of these vulcanization accelerators and rubbers may be used.

The rubber molding of the present invention may be any rubber product reinforced with the polyester fiber for rubber reinforcement of the present invention, and examples thereof include tires, belts and hoses.

[0013]

The present invention will be described in more detail with reference to the following examples. (Adhesive treatment conditions) 13% by weight of 1% aqueous sodium hydroxide solution, 16.6 parts by weight of resorcin, 37% formalin 1
5 parts by weight of water and 205 parts by weight of water were mixed and aged at 25 ° C. for 4 hours, and then Piratex (manufactured by Sumitomo Nogatak Co., 41
% Styrene-butadiene-vinylpyridine copolymer latex) 100 parts by weight, and aged at 25 ° C. for 30 hours.
FL aqueous solution was obtained. To this RFL aqueous liquid, VALQUABOND E
(Valnax product, 20% P-chlorophenol
Ammonia solution of resorcin-formalin condensate) 1
The cord was immersed in an adhesive solution obtained by adding 10 parts by weight for 5 seconds, dried at 100 ° C. for 3 minutes, and then heat-treated at 250 ° C. for 1 minute.

Example 1, Comparative Example 1 PET dried chips (hereinafter referred to as PET chips) having an intrinsic viscosity of 1.01 and an ECT with an MFR of 18 g / 10 min.
An FE chip (hereinafter referred to as ECTFE chip) was prepared. The ECTFE chip was mixed at 4% by weight with respect to the mixed chip of the PET chip and the ECTFE chip. This mixed chip is melt-spun and drawn by an extruder type melt-spinning machine equipped with a gear pump, a filtration layer, and a spinneret to obtain 1000
A denier / 192 filament polyester fiber was obtained. The polyester fiber was twisted 40 times / 10 cm, twisted into two, and further twisted 40 times / 10 cm to obtain a cord. The cord was treated with an adhesive and embedded in an unvulcanized rubber composition shown below, and the temperature was maintained at 170 ° C. for 5
After vulcanization at 0 kg / cm ² for 3 hours, the cord was taken out of the rubber and the strength was measured. The results are shown in Table 1 together with the strength of the blank cord not treated in the rubber. Unvulcanized rubber composition Natural rubber 70 parts by weight SBR (styrene-butadiene rubber) 30 parts by weight Zinc white 3.5 parts by weight Stearic acid 1.5 parts by weight Carbon black 35 parts by weight Process oil 3.5 parts by weight Sulfur 2. 5 parts by weight Dibenzothiazole / disulfide 1 part by weight For comparison, in Example 1, the same procedure as in Example 1 except that the ECTFE chip was not added is shown in Table 1 (Comparative Example 1). .

Examples 2 to 8 and Comparative Examples 2 to 3 Codes were obtained in the same manner as in Example 1 except that the mixing ratio of the ECTFE chips in Example 1 was changed as shown in Table 1. Then, the cord treated with the adhesive was embedded in the rubber composition shown in Example 1 by using a vulcanization mold and vulcanized at 140 ° C. for 40 minutes at 50 kg / cm ² ,
The block consisting of rubber and cord was taken out from the mold, allowed to cool, and then the cord was pulled out from the rubber. The load at this time was measured and the initial adhesive strength is shown in Table 1.

The rubber-reinforcing polyester fiber material of the present invention suppresses deterioration when exposed to a high temperature in rubber for a long time, and has excellent adhesiveness with rubber. Turns out to be excellent.

[0017]

[Table 1]

[0018]

EFFECT OF THE INVENTION A polyester fiber material for rubber reinforcement containing 0.1% by weight or more and 10% by weight or less of the copolymer of ethylene and monochlorotrifluoroethylene of the present invention is
The rubber molded article using the polyester fiber material for rubber reinforcement of the present invention is excellent in adhesiveness with rubber, can suppress deterioration when exposed to high temperature in rubber for a long time, and is stable. It is useful as a tire, belt, hose, etc.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location C08J 5/04 CEQ 7310-4F C08L 21/00 7211-4J D01F 6/62 302 A 7199-3B F16G 1/08

Claims (2)

[Claims] 1. A rubber-reinforcing polyester fiber comprising 0.1% by weight or more and 10% by weight or less of a copolymer of ethylene and monochlorotrifluoroethylene. 2. A rubber molding reinforced with a polyester fiber containing 0.1% by weight or more and 10% by weight or less of a copolymer of ethylene and monochlorotrifluoroethylene.