JPH11279886A - Synthetic fiber code for reinforcing rubber and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a synthetic fiber code for reinforcing a rubber, excellent in adhesion to the rubber, heat resistance in the rubber and degradation resistance against ethylene glycol by twisting a specific p-phenylene sulfide fiber yarn and a polyamide fiber yarn together, and imparting an adhesive treating agent to the twisted yarns. SOLUTION: This synthetic fiber code for reinforcing a rubber is produced by twisting a polyphenylene sulfide fiber yarn having >=4.5 g/de strength, >=60 g/de initial tensile resistivity and <=8% shrinkage in hot air at 180 deg.C, and obtained by attaching 0.3-2.0 wt.% treating agent containing 0.5-5% antioxidant component to the polyphenylene sulfide fiber, and a polyamide fiber yarn in a ratio of the polyphenylene sulfide fiber yarn to the polyamide fiber yarn requlated so as to be (3/7)-(7/3), together, and imparting an adhesive treating agent obtained by mixing a mixture of a resorcin-formalin preconclensate with a rubber latex, with further a chlorophenol compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a synthetic fiber cord for reinforcing rubber and a method for producing the same. More particularly, the present invention relates to a synthetic fiber cord for rubber reinforcement useful as a reinforcing material for rubber products such as tires, rubber hoses and belts. More specifically, it has good adhesion to the adhered rubber, and has significantly improved heat resistance in rubber and deterioration resistance to chemicals such as ethylene glycol and mineral oil, that is, the chemical resistance is significantly improved. The present invention relates to a synthetic fiber cord for rubber reinforcement having excellent durability.

[0002]

2. Description of the Related Art Fiber yarns made of polyamides represented by polycapramide (nylon 6) and polyhexamethylene adipamide (nylon 66) are excellent in high strength, high adhesiveness and durability, so that they can be used in various industries. They are widely used as rubber reinforcing cords such as tire cords, power transmission belts, conveyor belts and rubber hoses.

However, radiator hoses and power steering hoses for automobiles which are continuously used at high temperatures are required to have not only mechanical properties but also better heat resistance and chemical resistance. Conventional general-purpose materials such as yarn cannot solve these problems.

[0004] On the other hand, polyphenylene sulfide is a polymer having excellent heat resistance, chemical resistance, oil resistance, and the like, and is attracting attention as a high-performance engineering plastic utilizing these characteristics.

[0005] Fiber yarns composed of polyphenylene sulfide are disclosed, for example, in JP-A-49-54617, JP-A-61-215715, and JP-A-Hei.
No. 239109, all of which mention the properties of fiber yarns. However, there is no description about adhesiveness to rubber, high strength, and heat shrinkability which are required as a reinforcing material for a rubber hose. Therefore, the polyphenylene sulfide fiber yarn described in these conventional examples does not have sufficient properties as a reinforcing material for a reinforced rubber product, particularly a rubber hose. Was.

As described above, despite the fact that polyphenylene sulfide fiber yarns have excellent heat resistance, chemical resistance and oil resistance, they can be used as reinforcing materials for reinforcing rubber products, especially rubber hoses. Has not been carried out conventionally, and this is thought to be due to the fact that polyphenylene sulfide fiber yarn originally lacks adhesion to rubber and has problems such as poor durability when used as a hose. Can be

[0007]

SUMMARY OF THE INVENTION The present invention has been achieved as a result of studying to solve the problems in the prior art described above.

Accordingly, it is an object of the present invention to have good adhesion to a rubber to be adhered, and to significantly improve heat resistance in rubber and deterioration resistance to chemicals such as ethylene glycol and mineral oil, ie, chemical resistance. Another object of the present invention is to provide a synthetic fiber cord for rubber reinforcement which is excellent in the strength retention and durability of the fiber yarn.

[0009]

In order to solve the above-mentioned problems, the synthetic fiber cord for reinforcing rubber of the present invention mainly has the following constitution. That is, it is a cord in which a polyphenylene sulfide fiber yarn and a polyamide fiber yarn are twisted, and the fineness ratio between the polyphenylene sulfide fiber yarn and the polyamide fiber yarn is 3/7 to 7/3.
It is a synthetic fiber cord for rubber reinforcement characterized by the following.

The method for producing a synthetic fiber cord for rubber reinforcement according to the present invention mainly has the following constitution. That is,
After twisting a polyphenylene sulfide fiber yarn and a polyamide fiber yarn, a synthetic fiber cord for rubber reinforcement characterized by being treated with an adhesive treatment agent containing a mixture of a resorcinol-formalin precondensate and a rubber latex. It is a manufacturing method.

In the synthetic fiber cord for reinforcing rubber of the present invention, the strength of the polyphenylene sulfide fiber is 4.5 g / d or more, the initial tensile resistance is 60 g / d or more,
The dry heat shrinkage at 180 ° C. is 8% or less, and the polyphenylene sulfide fiber yarn has an antioxidant component of 0.5 to
It is a preferable condition that 0.3 to 2% by weight of the treating agent containing 5% by weight is adhered, and by applying these conditions, a more excellent effect can be expected. .

In the method for producing a synthetic fiber cord for rubber reinforcement according to the present invention, a polyphenylene sulfide fiber yarn and a polyamide fiber yarn are twisted and then a mixture of a resorcinol-formalin precondensate and a rubber latex is formed. Further, it is preferable that the treatment is carried out with an adhesive treatment agent containing a chlorophenol compound. By applying these conditions, it is possible to expect a more excellent effect.

[0013] Further, it is a preferable use to use it for reinforcing a radiator hose or a power steering hose of an automobile, and more excellent effects can be expected.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The synthetic fiber cord for rubber reinforcement according to the present invention comprises a cord obtained by twisting a polyphenylene sulfide fiber yarn and a polyamide fiber yarn.

As the polyphenylene sulfide resin which is a raw material polymer of the polyphenylene sulfide fiber used in the present invention, a commercially available product produced by a conventional method can be used. For example, para-dichlorobenzene and sodium disulfide are converted to N-methyl. -In pyrrolidone 200-
The polymer obtained by reacting at 250 ° C. and removing the solvent may be used in the form of pellets.

The polyphenylene sulfide resin used in the present invention has a melt flow rate (MFR) of 10
Preferably, the polymer is a linear polymer from 0 to 600, but trichlorobenzene (TCB) is 0.1% by weight.
The crosslinked polymer contained below may be used.

Melt flow rate (MFR)
Means AS with a measurement temperature of 316 ° C. and a load of 5 kgf.
Means the melt flow of the polymer as measured by the TM D1238-70 method.

The synthetic fiber cord for rubber reinforcement of the present invention is a cord obtained by twisting a polyphenylene sulfide fiber thread and a polyamide fiber thread, and the fineness ratio between the polyphenylene sulfide fiber thread and the polyamide fiber thread. Is set to 3/7 to 7/3. When the ratio of the fineness of the polyphenylene sulfide fiber yarn to the polyamide fiber yarn is less than 3/7, the heat resistance and chemical resistance of the obtained cord become insufficient because the amount of the polyphenylene sulfide fiber is small. On the other hand, when the fineness ratio of the polyphenylene sulfide fiber yarn and the polyamide fiber yarn exceeds 7/3, the adhesiveness of the cord to the rubber tends to decrease.

In the present invention, the obtained reinforced rubber product,
For example, assuming that the rubber hose has excellent pressure resistance, and particularly from the viewpoint of sufficiently exhibiting the performance as a rubber hose reinforcing material, the strength of the polyphenylene sulfide fiber yarn is 4.
It is desirable that the initial tensile resistance be 5 g / d or more and the initial tensile resistance be 65 g / d or more.

Further, from the viewpoint of preventing a defective shape of a reinforcing rubber product, for example, a rubber hose during vulcanization at the time of vulcanization, specifically, the deformation and wrinkling of the rubber hose, the polyphenylene sulfide fiber yarn has a dry heat shrinkage of 180 ° C. of 8%. % Is desirable.

In order to obtain such a polyphenylene sulfide fiber yarn, for example, a powder and / or pellet-like polymer of a polyphenylene sulfide resin having a melt viscosity index (MFR value) of 25 to 300 g / 10 min is prepared by: A method of removing sublimated low molecular weight substances by heating under a vacuum condition of −760 mmHg or lower at a temperature of 100 ° C. or higher and 200 ° C. or lower, and suppressing generation of bubbles and a three-dimensional crosslinking reaction.

From the viewpoint of preventing the strength of the fiber yarn from decreasing and preventing the single fiber from being cut during the drawing of the fiber, the bubbles and the insoluble matter in the polyphenylene sulfide fiber have a size in the fiber axial direction. Is 5 μm or less, the size in the fiber diameter direction is 1 μm or less, and the amount contained in a single fiber is preferably 1 piece / m or less.

Means for effectively removing such bubbles and insoluble matter as micro defects in the polyphenylene sulfide fiber include, for example, a metal filter having fine pores of 5 μm or less as a filter in a spinneret in a melting prevention step. A method using a nonwoven fabric is preferred.

From the viewpoint of easily obtaining the desired fiber yarn strength, the content of oligomers of hexamer or less among the oligomers in the polyphenylene sulfide resin is preferably 0.2% by weight or less.

As the polyamide fiber yarn used in the present invention, nylon 6 or nylon 66 capable of forming a high-strength raw yarn is used. Among them, the relative viscosity of sulfuric acid is 3 or more, preferably 3.5 or more. Ultrahigh-strength nylon 66 fiber yarns made of fibers made of high-molecular-weight nylon 66 and added with an antioxidant containing a copper compound are preferably used to impart durability against deterioration due to heat, light, oxygen, and the like. Can be

[0027] The method of spinning polyamide fiber yarns is
The stretching may be performed in two stages, or the stretching may be performed in one stage.

The polyphenylene sulfide fiber yarn contains 0.5 to 5% by weight of an antioxidant component from the viewpoint of effectively increasing the frictional force between the polyphenylene sulfide fiber and the roll surface and causing the yarn to break during drawing. It is preferable that 0.3 to 2% by weight of the treating agent is adhered.

The antioxidant contained in the treating agent has a function of preventing a reduction in adhesive strength due to oxidative deterioration with time of a reinforced rubber product, particularly a rubber hose for automobiles.

The treating agent used here is an aqueous emulsion oil or a completely non-hydrated oil, and preferably has a treating agent solid content of 5 to 40% by weight, more preferably 10 to 30% by weight.

The treating agent contains a smoothing agent component A, an emulsifying agent component B, a surfactant component C, and an antioxidant component D as solids, and 50 to 70% by weight of the smoothing agent component A.
It is preferable that a solid content is formed from a total of 100% by weight of 15 to 30% by weight of emulsifier component B, 15 to 30% by weight of surfactant component C, and 0.5 to 5% by weight of antioxidant component D. Is done.

Specific examples of the smoothing agent component A include esters of dihydric alcohols such as neopentyl glycol dilaurate and diethylene glycol dioleate and higher fatty acids, trihydric alcohols such as glycerin triolate and trinetyl roll propane triolate and higher fatty acids. Esters such as pentaerythritol tetraolate
Or higher alcohols and higher fatty acid esters, dioctyl sebacate, dioleyl adipate, esters of higher alcohols such as diisostearyl thiodipropionate and dibasic acid, dioleyl phthalate, trioctyl trimellitate, tetraoctyl pyromellitate Esters of higher alcohols and aromatic carboxylic acids, and esters of higher alcohols and higher fatty acids such as bityl stearate, isostearyl palmitate, oleyl lalate and oleyl oleate.

Specific examples of the emulsifier component B include 2-ethylhexyl alcohol, 2-nonyltridecanol,
Alkylene oxide adducts of alcohols (C6 to C26) such as undecylpentadecanol (n = 1 to
7).

A specific example of the surfactant component C is an ester compound of a polyhydric alcohol alkylene oxide adduct, wherein the number of moles of the alkylene oxide added is 10%.
Reaction products of ４０40 moles of compound with monocarboxylic and / or dicarboxylic acids. Examples of the ester compound include hydrogenated castor oil EO (25), stearic acid and maleic acid ester of hydrogenated castor oil ethylene oxide EO (25), and ethylene oxide EO (20) distearate.

Specific examples of the antioxidant D include a single component such as a phenolic antioxidant, a phosphoric acid antioxidant, an amine antioxidant, a hindered antioxidant, and a sulfur antioxidant. What mixed two or more types is mentioned.

When the synthetic fiber cord for rubber reinforcement is used as a rubber reinforcing material, such a treating agent moderately suppresses rapid penetration of the emulsified adhesive into the inside of the fiber, and allows the adhesive to be thinly and uniformly penetrated. It has the effect of improving the fatigue resistance of reinforced rubber products, especially rubber hoses.

In order to obtain the synthetic fiber cord for rubber reinforcement of the present invention, first, a polyphenylene sulfide fiber yarn and a polyamide fiber yarn are twisted at the above-mentioned fineness ratio.

In the case of twisting the fiber yarn, it is preferable to pre-twist the polyphenylene sulfide fiber yarn and the polyamide fiber yarn in advance. Then, aligning the ply-twisted polyphenylene sulfide fiber yarn and the ply-twisted polyamide fiber yarn, and twisting in the opposite direction to the direction of the ply twist, or in the same direction as the direction of the ply twist A raw cord is obtained by twisting.

The number of twists of the above-mentioned lower twist and upper twist is 4 to
It is preferably in the range of 15 times / 10 cm.

The rubber reinforcing synthetic fiber cord of the present invention may be one obtained by applying an adhesive treatment liquid to the above-mentioned raw cord, and by applying this treatment liquid, the adhesiveness of the cord to rubber can be significantly increased. .

In the present invention, as the adhesive treatment liquid, a liquid mainly containing a mixture (RFL) of initial condensation of resorcinol / formaldehyde and rubber latex is preferably used.

In the above RFL, the resorcinol-formaldehyde precondensate is obtained by condensing resorcinol and formaldehyde in the presence of an alkali catalyst or an acid catalyst. Those in the range of 2/3 to 4/3 are particularly preferred.

The above-mentioned RFL is obtained by reacting a compound represented by the following chemical formula (I) with formaldehyde at a ratio of 1/10 to 10/10 (weight ratio) in the presence of an alkali catalyst. The condensate, a rubber latex mixture obtained by mixing rubber latex and ammonia water at a ratio of 10 / 0.1 to 20/1 (weight ratio) are mixed with 1/8
It is preferable that the mixture is a mixture of １ ／ (solid content weight ratio).

[0044]

Embedded image (Where n represents 0 or an integer of 1 to 15) Here, as the compound represented by the chemical formula (I),
A novolak resin obtained by previously reacting dihydroxybenzene with formaldehyde in the absence of a catalyst or under an acidic catalyst is used. Specifically, this compound is, for example, 0.1 mol of formaldehyde per 1 mol of resorcinol.
And a compound condensed with 7 mol or less (for example, trade name “Sumikanol 700” (registered trademark, manufactured by Sumitomo Chemical Co., Ltd.)).

When using a novolak-type condensate of resorcinol and formalin in the RFL,
After dissolving this in an aqueous alkali catalyst dispersion, it is preferable to add formaldehyde to make the molar ratio equivalent to the resorcinol-formalin initial condensate.

The rubber latex in the above RFL includes a vinylpyridine-styrene-butadiene copolymer latex (VP latex) and a styrene-butadiene copolymer latex (S
BR latex), butadiene latex (BR latex), acrylonitrile-butadiene copolymer latex (NBR latex), chloroprene latex (CR latex), chlorosulfonated polyethylene latex (CSM latex), butyl rubber latex (IIR latex), An acrylate rubber latex and a natural rubber latex (NR latex), or a latex obtained by copolymerizing these latexes with an ethylenically unsaturated acid, are used alone or in combination as appropriate.

In the present invention, a treatment liquid containing a resorcinol-formaldehyde precondensate, a rubber latex and a chlorophenol compound may be used as the adhesion treatment liquid.

Examples of the chlorophenol-based compound include “Casabond E” (registered trademark, manufactured by Thomas Swan Company), “Denabond”, “Denabond A”, and “Denabond K” (registered trademark, Nagase Kasei Co., Ltd.) 2) bis (2,4-dihydroxyphenylmethyl)
-4-Chlorophenol is preferred.

Chlorophenolic compounds and resorcinol
Mixing with a formaldehyde precondensate can significantly improve the adhesion between the chloroprene rubber and the cord, which is preferable.

The weight ratio of the resorcinol-formaldehyde precondensate (RF) to the rubber latex (L) in the adhesive treatment solution in terms of the solid content is good, and
While preventing the cord and the knitted fabric from increasing in tackiness,
From the viewpoint of preventing the treated cord and knitted fabric from becoming too hard and deteriorating the adhesion to rubber, 1/15 to 1
/ 1, more preferably 1/10 to 1/2.

When a chlorophenol-based compound is used in combination with the adhesive treatment solution, RFL and a chlorophenol-based compound are used from the viewpoint of preventing the flexibility of the cord and the knitted fabric from deteriorating, while ensuring sufficient adhesiveness. The preferred weight ratio with the compound is 1/2 to 10/1.

The adhesion amount of the adhesive treatment liquid used in the present invention is to obtain a sufficient adhesive strength, to prevent the flexibility of the cord from being impaired and to prevent the cord from becoming too sticky, and to prevent the occurrence of dip scum. From the viewpoint of preventing the process passability at the time of manufacturing a rubber reinforced product from being hindered due to, for example, the polyphenylene sulfide fiber yarn and the polyamide fiber yarn are twisted with each other, and the solid content is 2 to 8% by weight based on the cord. It is preferred that Next, an example of the method for producing the synthetic fiber cord for rubber reinforcement of the present invention will be described.

First, an example of a typical method for producing polyphenylene sulfide fiber will be described.

First, a commercially available polyphenylene sulfide resin is dried in pellet form at a temperature of 100 to 200 ° C. under a vacuum condition of −760 mmHg or less for 2 hours or more, usually 4 to 48 hours.

Next, the polyphenylene sulfide resin is dissolved preferably in an extruder type spinning machine.
After passing through a sintered metal nonwoven fabric filter having fine pores of 0 μ or less, 0.1 to 0.5 mm, preferably 0.2
The fiber is spun from a spinneret having a pore of about 0.3 mm to form a spun yarn.

Next, the spun yarn is usually placed 5 to 5 immediately below the spinneret.
After passing through a high-temperature atmosphere surrounded by a heat retaining cylinder or a heating cylinder in which the atmosphere between 30 cm is 200 to 350 ° C., 1
Cool with hot air of 00 ° C or less.

The high-temperature atmosphere provided directly below the die is appropriately selected in accordance with the melt flow rate (MFR) of the polymer, the fineness of the yarn and the spinning speed.

Subsequently, the spun yarn is uniformly cooled and solidified with hot air or cold air of 100 ° C. or less, preferably 20 ° C. to 80 ° C., and after the oil agent (treatment agent) is attached, it is usually 300 to 10%.
It is picked up by a pick-up roller rotating at 00 m / min.

The undrawn yarn is usually sent to a hot drawing step continuously without being wound, and is usually subjected to multistage drawing of two or more stages. The draw ratio is 3 to 5.5 times, and preferably 3.5 to 5 times, depending on the spinning conditions. 2
When using step stretching, the first step stretching is 70% of the total magnification.
As described above, the content is usually set to 75 to 85%, and the remainder is performed in the second stretching. The stretching temperature is usually set to a maximum temperature of 120 to 180 ° C.

The stretching heat treatment here is generally performed on a heating roller, but a non-contact stretching heat treatment may be performed by providing a heating medium, for example, an infrared heater, between the stretching rollers.

The drawn polyphenylene sulfide fiber yarn is usually wound up after being subjected to relaxation heat treatment with a relax roll. The relaxation rate after the heat treatment is usually in the range of 0 to 10%, preferably 2 to 6%.

Next, the obtained polyphenylene sulfide fiber yarn is passed through an air nozzle in front of a winder, if necessary, to impart confounding.

Then, the obtained polyphenylene sulfide fiber yarns are singly or plurally aligned, and the number of twists is 4
Twisting so as to be about / 10 cm gives a twisted cord.

On the other hand, nylon 66 multifilament having a raw yarn strength of 9.6 g / d and 840 denier obtained by melt-spinning and stretching nylon 66 having 98% sulfuric acid relative viscosity of 3.70 was used 4 times / Twist with a twist number of about 10 cm to obtain a lower twist cord.

Next, the ply-twisted cord of the polyphenylene sulfide fiber yarn and the ply-twisted cord of the nylon 66 fiber yarn are placed in a direction opposite to the direction of the ply twist, for example, 4 times / 1.
Twist with a twist number of about 0 cm to obtain a raw cord.

Then, the obtained raw code is subjected to RFL
Is given.

When the synthetic fiber cord for rubber reinforcement of the present invention is used as a reinforcing material such as a radiator hose or a heater hose, good adhesion to ethylene-propylene-diene terpolymer rubber (hereinafter, EPDM) is obtained. Although necessary, in this case, it is desirable to use the following RFL.

In the presence of an alkali catalyst, resorcinol and formalin are mixed at a molar ratio of about 2/3, and aged for 2 hours to obtain an initial condensate having a solid content of about 10% by weight.
About 100 parts by weight of a mixed latex obtained by mixing vinylpyridine-styrene-butadiene copolymer latex (VP latex) and polybutadiene latex (BR latex) at a solid content weight ratio of about 50/50,
By mixing about 12.5 parts by weight and aging for about 24 hours, an RFL having a solid content of about 30% by weight is prepared.

Next, about 25% by weight of a chlorophenol compound was added thereto, and the solid content was reduced to 15% by weight with water.
Degree.

Next, the raw cord was immersed in the above-mentioned adhesive treatment liquid using a computer treater (manufactured by Ritzler), and dried at about 150 ° C. for about 2 minutes.
After heat treatment at about 0 ° C. for about 1 minute, the resulting treated cord is wound up with a winder, whereby the synthetic fiber cord for rubber reinforcement of the present invention can be obtained.

While preventing the RFL from solidifying and adhering to the roller to reduce the amount of adhering to the braid, it also prevents adhesion unevenness from occurring and deterioration in adhesion to rubber, while preventing blister (waste). From the viewpoint of preventing the occurrence of cracks, the drying temperature of the raw cord to which the above-mentioned adhesive treatment liquid is attached is 70 to 150
C. is preferred.

Further, from the viewpoint of preventing RFL from deteriorating and lowering the adhesiveness with rubber while preventing the adhesiveness with rubber from lowering, the temperature of the heat treatment after drying is from 170 to 170.
A range of 250 ° C. is preferred.

Further, the synthetic fiber cord for rubber reinforcement of the present invention may be subjected to a wet heat treatment, for example, at 145 ° C. for 30 minutes in an autoclave, if necessary, after the above heat treatment.

The rubber reinforced using the synthetic fiber cord for reinforcing rubber of the present invention includes natural rubber (NR), styrene-butadiene rubber (SBR), and isoprene rubber (I).
R), butyl rubber (IIR), halogenated butyl rubber (X-IIR), chloroprene rubber (CR), EPD
M, nitrile rubber (NBR), hydrogenated nitrile rubber (H
NBR), chlorosulfonated polyethylene rubber (CS
M), acrylic rubber (ACM), hydrin rubber (CH
C), chlorinated polyethylene rubber (CPE) or a mixture of these various rubbers, etc., and may be any rubber type.
EPDM is mainly used.

The synthetic fiber cord for reinforcing rubber of the present invention can be used for reinforcing various reinforcing rubber products such as tire cords, power transmission belts, conveyor belts and rubber hoses by taking advantage of its excellent properties. It exhibits ideal performance especially when applied to rubber hoses for automobiles, especially hoses for radiators or power steering hoses.

[0076]

EXAMPLES Hereinafter, the structure and effects of the present invention will be described more specifically with reference to examples.

The respective measured values in the following examples were obtained by the following methods. In addition, parts and% in Examples all show parts by weight and% by weight.

[Melt Viscosity Index] Measured according to the standard of ASTM-D-1238-70 using a melt flow tester manufactured by Shimadzu Corporation.

[Original yarn fineness] JIS L 1013 (19
92) was measured according to 7.3.

[Original yarn strength and elongation] JIS L 1013
(1992) 7.5.

[Initial Tensile Resistance of Raw Yarn] JIS L 1
013 (1992) at 7.10.

[Dry Heat Shrinkage of Raw Yarn] After the fibers were freely shrunk in a dry heat open at 180 ° C. for 30 minutes, JIS L
It was measured according to the standard of No. 1013.

[Adhesion Treatment Adhering Amount] Filament 100
g was immersed in trichlorethylene, and the treating agent was separated and extracted, and calculated by a gravimetric method.

[Cord Strength] A sample was heated at 20 ° C. and 65% RT.
After being left in a temperature control room for 24 hours or more, a sample length of 25 was measured using a Tensilon tensile tester manufactured by Orientec Co., Ltd.
cm, taking the SS curve at a take-off speed of 30 cm / min,
The strength per denier was sought.

[Treatment Cord Adhesive Strength] Rubber Compounding Formulation (Parts) EPDM 100 Zinc White 5.0 Stearic Acid 1.0 Carbon Black 80.0 Processing Oil 0.3 Sulfur 1.5 2-Mercaptobenzothiazole 0.5 Tetra Methylthiuram disulfide 1.0 A test piece having a width of 25 mm was prepared using the above-mentioned compounded rubber and the treated cord, and the treated cord / rubber peeling force was measured by a peeling test method described in JISK 6328 (1995). That is, after unvulcanized rubber was pasted on an aluminum pipe having a diameter of 10 cm and a length of 6 cm, cords were arranged without gaps, and after unvulcanized rubber was pasted, a wrapping cloth (35 mm, manufactured by Toray Industries, Inc.) was used. After winding and vulcanizing at 150 ° C. for 30 minutes using an autoclave, JIS
According to the peel test method described in K 6328,
The rubber peeling force was measured.

[Heat resistance] The treated cord was placed in an oven heated to 150 ° C. and heat-treated for 750 hours. After taking out the cord, the cord strength was measured by the above method, and the heat resistant strength retention was determined by the following equation. Strength retention (%) = (cord strength after heat treatment / cord strength before heat treatment) × 100.

[Glycol (LLC) Resistance] The treated cord was immersed in a bath of a commercially available LLC (long life coolant) for automotive radiators heated to 150 ° C. for 250 hours, and the strength before and after the treatment was measured. The strength retention was determined by the following formula, and was used as a measure of durability.

Strength retention (%) = (strength after immersion / strength before immersion) × 100 (Example 1) Melt viscosity index (MFR value) is 54 g / 10
The min. polyphenylene sulfide resin pellets were left in a vacuum heater at -760 mmHg (gauge pressure, the same applies hereinafter) at a temperature of 150 ° C. for 16 hR or more. After allowing to cool, feed into the extruder of the spinning machine,
After melting at a temperature of 335 ° C. under a vacuum of mHg and filtering through a metal non-woven fabric filter having fine pores of 5 μm or less, the atmosphere of 100 mm immediately below the spinneret having a spinneret diameter of 0.50 mm and 50 holes was heated to 300 ° C. Discharged into the maintained slow cooling zone.

Further, a non-aqueous treating agent containing 3.5% of an antioxidant was applied to the yarn passed through the cooling zone,
After drawing at m / min, the film was continuously stretched and heat-treated on a heating roller, and stretched in three stages at a total stretching ratio of 4.3 times.

Then, it was heat-treated at a relaxation rate of 3% and wound up to obtain a yarn fineness of 250 denier, a treatment agent adhesion amount of 1.6%, a yarn strength of 5.75 g / d and an initial tensile resistance of 7%.
A polyphenylene sulfide filament fiber yarn having 4.8 g / d, a dry heat shrinkage of 180 ° C. of 5.8%, and hexamer or less oligomers, insolubles and almost no bubbles inside the fiber was obtained.

The 250-denier polyphenylene sulfide filament fiber yarn thus obtained was
The main thread was aligned and twisted with a twisting machine so that the number of twists was 4 T / 10 cm, and a twisted cord was obtained.

On the other hand, nylon 66 having 98% sulfuric acid relative viscosity of 3.70 was melt spun and stretched to obtain a raw yarn strength of 9.
6 g / d, 840 denier nylon 66 fiber yarn
Twisting was performed with a twist number of times / 10 cm to obtain a twisted cord.

Next, the ply twisted cord made of polyphenylene sulfide fiber yarn and the ply twisted cord made of nylon 66 fiber yarn are turned four times / 1 in the direction opposite to the direction of the ply twist.
The upper cord was twisted with a twist number of 0 cm to obtain a raw cord.

On the other hand, in the presence of an alkali catalyst, resorcinol and formalin were mixed at a molar ratio of 2/3, and the mixture was aged for 2 hours to obtain an initial condensate having a solid content of 10% by weight. 12.5 parts of butadiene copolymer latex (VP latex) and 100 parts of mixed latex in which polybutadiene latex (BR latex) is mixed at a solid content weight ratio of 50/50 are mixed and aged for 24 hours. Thus, RFL having a solid content of 30% was prepared.

Next, a chlorophenol-based compound “Denabond” (registered trademark, manufactured by Nagase Kasei Co., Ltd.)
Was added, and the solid content concentration was adjusted to 15% with water.

Next, the raw cord was immersed in the above-mentioned treatment solution using a computer treater (manufactured by Ritzler), dried at 150 ° C. for 120 seconds, and subsequently heat-treated at 240 ° C. for 60 seconds. The processing code was wound up with a winder.

Further, this dip cord is subjected to a wet heat treatment at 150 ° C. for 30 minutes in an autoclave,
A synthetic fiber cord for rubber reinforcement of the present invention was obtained.

Next, after wrapping the unprocessed code with a shackle,
After being removed from the shackles, it was put into an autoclave, treated with steam at 145 ° C. for 30 minutes, and then dried at room temperature to obtain a treated code.

The strength, adhesion, heat resistance and LLC resistance of the treated cord were evaluated. The results are shown in Table 1.

As is clear from the results shown in Table 1 and Table 2 described later, the synthetic fiber cord for rubber reinforcement of the present invention (Examples 1 to 5) is equivalent to the conventional nylon 66 fiber cord (Comparative Example 4). It has high adhesiveness, and has higher heat resistance and resistance than conventional nylon 66 fiber cord, polyphenylene sulfide fiber cord (Comparative Example 3) and synthetic fiber cords (Comparative Examples 1 and 2) which do not satisfy the conditions of the present invention. Chemical resistance such as ethylene glycol property was remarkably improved.

[0101]

[Table 1] (Examples 2 to 5) The same operation as in Example 1 was performed except that the mixing ratio of the polyphenylene sulfide fiber yarn and the nylon 66 fiber yarn and the adhesion amount of the adhesive treatment liquid were changed as described in Table 1. The treatment cord was evaluated for strength, adhesive strength, heat resistance and LLC resistance, and the results are shown in Table 1.

(Comparative Examples 1-2) The same as in Example 1 except that the mixing ratio of the polyphenylene sulfide fiber yarn and the nylon 66 fiber yarn and the amount of adhesion of the adhesive treatment liquid were changed as shown in Table 2. , And the strength, adhesion, heat resistance and LLC resistance of the treated cord were evaluated. The results are shown in Table 2.

[0103]

[Table 2] (Comparative Example 3) Eighty 250 denier polyphenylene sulfide filament fiber yarns obtained in Example 1 were aligned and twisted with a twisting machine so that the number of twists was 4 T / 10 cm. Got the code. Otherwise, the same operation as in Example 1 was performed, and the obtained treated cord was evaluated for strength, adhesive strength, heat resistance and LLC resistance, and the results are shown in Table 2.

(Comparative Example 4) 98% sulfuric acid relative viscosity 3.00
Of nylon 66 is melt-spun and stretched, and two nylon 66 fiber yarns having a raw yarn strength of 9.4 g / d and 1260 denier are aligned and twisted at a twist of 4 times / 10 cm to obtain polyphenylene sulfide. A raw cord containing no filament yarn was obtained. Otherwise, the same operation as in Example 1 was performed, and the obtained treated cord was evaluated for strength, adhesive strength, heat resistance and LLC resistance, and the results are shown in Table 2.

(Example 5) Resorcin and formalin were mixed at a molar ratio of 2/3 in the presence of an alkali catalyst.
The initial condensate having a solid content of 10% obtained by aging for 2 hours is
Chloroprene-based latex (2,3-dichloro-1,3
(Butadiene / 2-chloro-1,3-butadiene ratio is 1/9 in terms of solids weight ratio) 1100 parts was mixed with 100 parts and aged for 24 hours to obtain an R of 30% solids.
FL was prepared.

Next, a chlorophenol-based compound “Denabond” (registered trademark, manufactured by Nagase Kasei Co., Ltd.)
Was added, and the solid content was adjusted to 20% with water.

This RFL was diluted with water to obtain a solid content of 1%.
A treatment solution of 5% was used.

Next, the above-mentioned treatment liquid was applied to the raw cord obtained in Example 1 using a computer treater (manufactured by Ritzler), drained with an air wiper, and kept at 120 ° C. for 100 seconds. It was dried and subsequently heat treated at 210 ° C. for 60 seconds.

The strength, adhesive strength, heat resistance and LLC resistance of the treated cord were evaluated, and the results are shown in Table 1.

[0110]

The synthetic fiber cord for rubber reinforcement of the present invention is
It has good adhesion to the rubber to be adhered, and has significantly improved heat resistance in rubber and deterioration resistance to chemicals such as ethylene glycol and mineral oil, that is, chemical resistance, and has excellent fiber strength retention and durability. Taking advantage of these excellent properties, it can be widely applied to reinforcement of various reinforcing rubber products such as tire cords, power transmission belts, conveyor belts and rubber hoses. It exhibits ideal performance especially when applied to automotive rubber hoses, especially brake hoses, cooler hoses, radiator hoses or power steering hoses.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI D06M 15/693 D06M 15/693 // D06M 101: 34

Claims (6)

[Claims] 1. A cord obtained by twisting a polyphenylene sulfide fiber yarn and a polyamide fiber yarn, wherein the polyphenylene sulfide fiber yarn and the polyamide fiber yarn have a fineness ratio of 3/7 to 7/3. A synthetic fiber cord for rubber reinforcement, characterized in that there is a cord. 2. The polyphenylene sulfide fiber yarn has a strength of 4.5 g / d or more, an initial tensile resistance of 60 g / d or more, and a dry heat shrinkage of 180 ° C. of 8% or less. The synthetic fiber cord for rubber reinforcement according to 1. 3. A polyphenylene sulfide fiber yarn containing 0.5 to 5% by weight of a treatment agent containing an antioxidant component.
2. The method according to claim 1, wherein the coating is applied in an amount of 3 to 2% by weight.
Or the synthetic fiber cord for rubber reinforcement according to 2. 4. A rubber reinforcement comprising: twisting a polyphenylene sulfide fiber yarn and a polyamide fiber yarn, and then treating with a bonding agent containing a mixture of a resorcinol-formalin precondensate and a rubber latex. Manufacturing method of synthetic fiber cord for use. 5. The method for producing a synthetic fiber cord for reinforcing rubber according to claim 4, further comprising treating with a bonding agent containing a chlorophenol compound. 6. The synthetic fiber cord for reinforcing rubber according to claim 1, which is used for reinforcing a radiator hose or a power steering hose of an automobile.