JPH11279880A - 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, steam resistance and chemical resistance by twisting a specific polyphenylene sulfide fiber yarn and a polyester fiber yarn together and imparting an adhesive treating liquid to the twisted yarns. SOLUTION: This synthetic fiber code for reinforcing a rubber is obtained by twisting a polyphenylene sulfide fiber yarn having >=4.5 g/de strength, >=60 g/de initial tensile resistivity and <=8% shrinkage in dry air at 180 deg.C, and obtained by attaching 0.3-2 wt.% treating liquid containing 0.5-5 wt.% antioxidant component, and a polyester fiber, in a ratio of the sizes of the polyphenylene sulfide fiber yarn to the polyester fiber yarn regulated so as to be (3/7)-(7/3) together, dipping the twisted yarns into the first adhesive treating liquid containing a polyepoxy compound, a blocked isocyanate and/or an ethyleneurea compound, a rubber latex and a silicic acid compound, drying and heat-treating the dipped yarns, further dipping the dried and heat-treated yarns into the second adhesive treating liquid containing a resorcin-formalin precondensate, the rubber latex and a chlorophenol compound, and drying and heat-treating the dipped yarns.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic fiber cord for reinforcing rubber useful as a reinforcing material for rubber products such as tires, rubber hoses and belts, and a method for producing the same. More specifically, it has good adhesion to the adherend rubber, and has significantly improved steam resistance and chemical resistance.
The present invention relates to a synthetic fiber cord for rubber reinforcement having excellent fiber strength retention and durability and a method for producing the same.

[0002]

2. Description of the Related Art Since polyester fiber yarns have excellent mechanical strength and low elongation, taking advantage of these characteristics, they are widely used as reinforcing materials for rubber products such as tires, rubber hoses and belts.

[0003] However, in these reinforced rubber products, the polyester fiber yarn is used by being embedded in the rubber product as a reinforcing material. Will be affected.

[0004] For example, in rubber, thiuram-based, sulfenamide-based or guanidine-based vulcanization accelerators,
Amine-based antioxidants are often added,
For example, these compounded compounds are used during the vulcanization process during the production of automobile tires, during high-speed running, during the vulcanization process during the production of hoses and the like, and during use in a high-temperature atmosphere in an engine room. Induces the deterioration of
There has been a problem that the performance as a fiber thread for rubber reinforcement tends to be remarkably reduced.

[0005] In addition, when vulcanizing rubber using steam, there is also a problem that the polyester fiber yarns in the rubber are affected by the hydrolysis by steam, so that they are significantly deteriorated. .

For this reason, various studies have been made in recent years for the purpose of improving the above-mentioned drawbacks. For example, a technique of compounding a rubber with a vulcanization accelerator or an anti-aging agent which causes less deterioration of the polyester fiber yarns has been proposed. However, in such a method, there is a problem that it is difficult to obtain a vulcanized rubber satisfying the desired properties because the compounding composition of the rubber is significantly restricted.

On the other hand, attempts have been made to improve the above-mentioned drawbacks by improving the polyester fiber itself. For example, it has been proposed to reduce the amount of terminal carboxyl groups contained in the polyester fiber. The effect of sufficiently suppressing the deterioration of fibers in rubber to a practical level has not been obtained.

On the other hand, polyphenylene sulfide is attracting attention as a high-performance engineering plastic having excellent characteristics such as heat resistance, chemical resistance and oil resistance.

[0009] Polyphenylene sulfide fiber yarns are disclosed, for example, in JP-A-49-54617, JP-A-61-215715 and JP-A-Hei.
No. 239109, etc., all of which mention a description of fiber yarn properties. However, in these conventional examples, adhesion to rubber, which is a necessary property as a reinforcing material for rubber hoses, is high. Since no consideration is given to strength and heat shrinkability, the polyphenylene sulfide fiber yarns described in these conventional examples have sufficient properties as a reinforcing material for reinforced rubber products, particularly rubber hoses. I could not say that I was doing it.

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 a reinforcing rubber product, particularly as a reinforcing material for rubber hoses. This has not been done conventionally, and this is because polyphenylene sulfide fiber yarn originally lacks adhesiveness with rubber and is caused by having a problem such as poor durability when used as a rubber hose, for example. Conceivable.

[0011]

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

Accordingly, an object of the present invention is to provide a rubber reinforcing material which has good adhesion to a rubber to be adhered, has significantly improved steam resistance and chemical resistance, and has excellent fiber strength retention and durability. An object of the present invention is to provide a synthetic fiber cord.

[0013]

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

The method for producing a synthetic fiber cord for rubber reinforcement according to the present invention mainly has the following constitution. That is, a polyphenylene sulfide fiber yarn and a polyester fiber yarn are twisted and treated with a first adhesive treatment liquid containing a polyepoxide compound, and then a second mixture containing a resorcinol-formaldehyde precondensate and a rubber latex is further added. This is a method for producing a synthetic fiber cord for rubber reinforcement, characterized by treating with a bonding treatment liquid.

In the synthetic fiber cord for reinforcing rubber of the present invention, the strength of the polyphenylene sulfide fiber yarn is 4.5 g / d or more, the initial tensile resistance is 60 g / d or more, and the dry heat shrinkage at 180 ° C. is 8 or more. % Or less, and the polyphenylene sulfide fiber yarn contains 0.1% of the antioxidant component.
It is a preferable condition that 0.3 to 2% by weight of a treating agent containing 5 to 5% by weight is adhered, and it is expected that a more excellent effect is exhibited by applying these conditions. Can be.

Further, in the method for producing a synthetic fiber cord for rubber reinforcement according to the present invention, a polyepoxide compound, a blocked isocyanate and / or an ethylene urea compound,
Treating with a first adhesive treatment liquid comprising a rubber latex and a silicate compound as an adhesive matrix component;
Treatment with a second adhesive treatment liquid further containing a chlorophenol compound is a preferable condition. By applying these conditions, it is possible to expect a more excellent effect.

[0017]

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 thread and a polyester fiber thread.

As the polyphenylene sulfide resin which is a 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- 200 to 25 in pyrrolidone
The polymer obtained by reacting at 0 ° C. and removing the solvent can be used by forming the polymer into a pellet.

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 the polyphenylene sulfide fiber thread and the polyester fiber thread, and the fineness of the polyphenylene sulfide fiber thread and the polyester fiber thread Is 3/7 to 7/3.
If the ratio of the fineness of the polyphenylene sulfide fiber yarn to the polyester fiber yarn is less than 3/7, the amount of the polyphenylene sulfide fiber is small, so that the cord has insufficient steam heat resistance and chemical resistance. On the other hand, when the fineness ratio of the polyphenylene sulfide fiber yarn and the polyester fiber yarn exceeds 7/3, the adhesiveness to 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 60 g / d or more.

Further, from the viewpoint of preventing a hose shape defect during vulcanization of a reinforced rubber product, for example, a rubber hose, specifically, 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, for example, a melt viscosity index (M
FR value) of a polyphenylene sulfide resin powder and / or pellet-like polymer having 25 to 300 g / 10 min under a vacuum condition of -760 mmHg or less.
A method in which sublimated low molecular weight substances are removed by heating in a range of 100 ° C. or more and 200 ° C. or less to suppress generation of bubbles and a three-dimensional crosslinking reaction is preferably adopted.

In order to prevent a decrease in the strength of the fiber market and to prevent a single fiber from being cut during drawing of the fiber, bubbles and insolubles in the polyphenylene sulfide fiber have a size of 5 μm or less in the fiber axis direction. It is preferable that the size in the radial direction is 1 μm or less, and the amount contained in the single fiber is 1 piece / m or less.

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

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 0.2%.
% By weight or less.

The polyester fiber used in the present invention is desirably a fiber obtained by melt-spinning a polyester containing terephthalic acid as a main bifunctional carboxylic acid and ethylene glycol as a main glycol component. It is composed entirely of polyesters in which 2,6-naphthalenedicarboxylic acid, 4,4-dicarboxyphenoxyethane, isocyanate groups and the like have been replaced, and polyesters in which part or all of ethylene glycol has been replaced by diethylene glycol, propylene glycol, butanediol, etc. Even fibers can be used.

The polyester may be a copolymer of a trifunctional compound such as trimesic acid, trimellitic acid, boric acid, phosphoric acid, glycerin and trimethylolpropane in a small amount.

Further, the polyester 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 method of spinning the polyester fiber may be a method in which spinning and drawing are performed in two steps, or a method in which both steps are performed in one step.

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, the polyphenylene sulfide fiber yarn contains 0.5 to 5% by weight of an antioxidant component. It is preferable that 0.3 to 2% by weight of the treating agent is adhered.

The antioxidant contained in the treating agent is as follows:
For example, it has a function of preventing a decrease in adhesive strength due to oxidative deterioration over time in a rubber hose for an automobile.

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

The processing agent contains a smoothing agent component A, an emulsifying agent component B, a surfactant component C, and an antioxidant component D as solids. The smoothing agent component A: 50 to 70% by weight, the emulsifying agent component B: 15 -30% by weight, surfactant component C: 15
What formed the solid content from 100 weight% of antioxidant component D: 0.5-5 weight% in total is preferably used.

Specific examples of the smoothing agent component A include esters of dihydric alcohols such as neopentyl glycol dilaurate and diethylene glycoldiolate 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) and the like.

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%.
A reaction product of ４０40 mol of a compound with a monocarboxylic acid and / or a dicarboxylic acid is included. The ester compound includes hydrogenated castor oil EO (25), stearic acid, maleic acid ester and hydrogenated castor oil ethylene oxide EO (25) and ethylene oxide EO (20).
And distearate.

Specific examples of the antioxidant D include a single component such as a phenolic antioxidant, a phosphoric acid-based antioxidant, an amine-based antioxidant, a hindered antioxidant, and a sulfur-based antioxidant. A mixture of more than one kind is mentioned.

When the synthetic fiber cord for rubber reinforcement is used as a rubber reinforcing material, such a treatment agent moderately suppresses the rapid penetration of the emulsified adhesive treatment agent into the interior of the fiber, and allows it to penetrate thinly and uniformly. It has the effect of improving the fatigue resistance of a rubber hose, for example.

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

In the case of twisting the fiber yarn, it is preferable that the polyphenylene sulfide fiber yarn and the polyester fiber yarn are individually pretwisted in advance. next,
Align the ply-twisted polyphenylene sulfide fiber yarn and the ply-twisted polyester fiber yarn,
A raw cord can be obtained by twisting in a direction opposite to the direction of plying or by plying in the same direction as the direction of plying.

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

Prior to rubber reinforcement, the above raw cord was treated with a two-bath adhesive formulation described below, that is, treated with a first adhesive treatment solution containing a polyepoxide compound, and further treated with a resorcinol-formaldehyde precondensate and rubber latex. By applying the prescription for treating with the second adhesive treatment liquid containing the mixture of the above, the adhesiveness to rubber is significantly enhanced.

The first adhesive treatment liquid may comprise a polyepoxide compound, a blocked isocyanate and / or an ethylene urea compound, a rubber latex and a silicate compound as an adhesive matrix component. More preferably further contains a chlorophenol compound in addition to the mixture of the resorcinol-formaldehyde precondensate and the rubber latex.

The polyepoxide compound used in the first adhesive treatment liquid is a compound containing two or more epoxy groups in one molecule, and specific examples thereof include glycerol, pentaerythritol, sorbitol, ethylene glycol, and polyethylene. Reaction products of polyhydric alcohols such as glycol, propylene glycol and the like with halogen-containing epoxides such as epichlorohydrin, and resorcinol, bis (4-hydroxyphenyl) dimethylmethane, phenol-formaldehyde resin and resorcinol-formaldehyde resin. Reaction products of polyhydric phenols with the halogen-containing epoxides, such as bis- (3,4-epoxy-6-methyl-dicyclohexylmethyl) adipate and 3,4-epoxycyclohexene epoxide; Polyepoxide compounds obtained by oxidizing the unsaturated bond moiety, include bisphenol A-type epoxy compounds and bisphenol A urethane-modified epoxy compound, which may be mixed using one or two or more kinds. Among them, a preferred polyepoxide compound is a reaction product of a polyhydric alcohol and epichlorohydrin (a polyglycidyl ether compound of a polyhydric alcohol).

Similarly, the blocked polyisocyanate compound used in the first adhesive treatment liquid is a compound which releases an blocking agent by heat to produce an active isocyanate compound. Phenylene diisocyanate, diphenylmethane diisocyanate, polyisocyanate compounds such as hexamethylene diisocyanate and triphenyl methane triisocyanate, phenols such as phenol, cresol, resorcinol, ε-caprolactam, lactams such as valerolactam, acetoxime,
Preferable examples include a reaction product with a blocking agent selected from oximes such as methyl ethyl ketone oxime and cyclohexane oxime, and ethyleneimine.

Among these blocked polyisocyanate compounds, the use of an aromatic polyisocyanate compound blocked with ε-caprolactam and an aromatic compound of diphenylmethane diisocyanate give good results.

Similarly, the ethylene urea compound used in the first adhesive treatment liquid is one which, when heated, causes the ethylene imine ring to open and reacts to improve the adhesiveness. A typical example thereof is hexamethylene diisocyanate. Reaction products of aromatic and aliphatic isocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and triphenylmethane diisocyanate with ethyleneimine.

Among these ethylene urea compounds, the use of an aromatic ethylene urea compound of diphenylmethane diethylene urea gives good results.

Incidentally, the first adhesive treatment liquid can contain either or both of the above-mentioned blocked polyisocyanate compound and ethylene urea compound.

Similarly, preferred rubber latexes contained in the first adhesive treatment liquid include vinyl pyridine-styrene-butadiene copolymer latex (VP latex) and styrene-butadiene rubber latex (SBR latex) according to the rubber to be adhered. ), Acrylonitrile-butadiene rubber latex (NBR latex), chloroprene rubber latex (CR latex), chlorosulfonated polyethylene latex (CSM latex), acrylate rubber latex and natural rubber latex (NR latex) or ethylene in these latexes Latex or the like obtained by copolymerizing a system unsaturated acid is used singly or as a mixture.

Similarly, silicate compounds preferably used in the first adhesive treatment liquid include silicon, magnesium,
An inorganic compound containing sodium and lithium as constituent elements and further containing or not containing fluorine and / or aluminum as constituent elements, and is a synthetic inorganic compound generally called smectite.

The above-mentioned silicate compounds, especially synthetic smectite, become a thixotropic dispersion when dispersed in water, have a stable viscosity, and have a function of increasing the specific surface area.

Accordingly, the silicate compound acts as a penetration inhibitor and a softening agent, and the rubber / fiber adhesive composition containing the silicate compound is stable even when the amount of adhesion to synthetic fibers is reduced. In addition to obtaining excellent adhesion to rubber, the treated cord becomes flexible, and a reduction in cord strength is effectively prevented.

Further, by the addition of the silicate compound, aggregation of the adhesive matrix component such as rubber latex in the adhesive composition is suppressed, and the adhesive matrix components are uniformly mixed and stabilized. Is uniformly adhered to the fiber surface under excellent cohesive force, so that even with a small amount of adhesion, excellent adhesion to rubber can be obtained.

From the viewpoint of preventing the initial adhesive strength of the treated synthetic fiber from decreasing, the compounding ratio of the polyepoxide compound in the first adhesive treatment liquid is preferably 10 to 25% by weight, more preferably 10 to 20% by weight. . The mixing ratio of the blocked polyisocyanate compound and / or the ethylene urea compound is preferably 20 to 35% by weight, more preferably 20 to 30% by weight. The compounding ratio of the rubber latex is preferably 0 to 70% by weight, more preferably 0 to 65% by weight.

The first adhesive treatment liquid is preferably used as a solution (including a dispersion) having a total solid content of the adhesive matrix component of 2 to 10% by weight, particularly 4 to 7% by weight.

[0060] From the viewpoint of sufficiently suppressing the decrease in the strength of the treated fiber cord and preventing the tendency of the adhesive strength of the treated fiber cord to rubber to decrease, the compounding amount of the silicate compound is set in the first adhesive treatment liquid. 1 to 15% by weight, and more preferably 3 to 10% by weight, based on the contained adhesive matrix component
Is preferable.

The mixture of the resorcinol-formaldehyde initial condensate and the rubber latex contained in the second adhesive treatment liquid is generally called RFL.
Abbreviated as FL.

In the above-mentioned RFL, the resorcinol-formaldehyde precondensate is obtained by condensing resorcinol and formaldehyde under an alkali catalyst or an acid catalyst, and the molar ratio of resorcinol to formaldehyde is 1/3.
Those having a range of from 〜１０ to 、, particularly from ／ to ／ are preferably used.

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).

[0064]

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, 0.7 mol of formaldehyde to 1 mol of resorcinol.
It is a compound condensed at a ratio of not more than mol (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 above-mentioned RFL, this is dissolved in an aqueous dispersion of an alkali catalyst, formaldehyde is added thereto, and the same molar amount as the resorcinol-formalin initial condensate is used. It is preferred to make the ratio.

The rubber latex in the 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 addition, the second adhesive treatment liquid is the same as the RFL
And a mixture of ethylene urea compound. Examples of the ethylene urea compound include reaction products of aromatic and aliphatic isocyanates such as hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and triphenylmethane diisocyanate with ethylene imine. In this case, the amount of the ethylene urea compound added for improving the adhesion is RFL from the viewpoint of ensuring that the effect of improving the adhesion is sufficient and preventing the cord from becoming hard and causing a decrease in strength.
3 to 30% by weight, further 10 to 20% by weight
Is preferable.

The second adhesive treatment liquid may be one obtained by adding a chlorophenol compound to RFL.

The chlorophenol compounds to be used include "Casabond E" (registered trademark, manufactured by Thomas Swan Co., Ltd.), "Denabond", "Denabond A", and "Denabond K" (registered trademark, Nagase Chemicals Co., Ltd.) 2) bis (2,4-dihydroxyphenylmethyl)
-4-chlorophenol.

Also in this case, the precondensate of resorcinol and formaldehyde is usually reacted in the presence of an alkali catalyst. The preferred molar ratio of resorcinol to formaldehyde is 1/1 to 3/1.

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

When a chlorophenol-based compound is used in combination with the second adhesive treatment liquid, while preventing the flexibility of the cord and the knitted fabric from decreasing, the RFL and the RFL are combined with each other from the viewpoint of ensuring sufficient adhesiveness. The preferred weight ratio with the chlorophenol compound is 1/2 to 10/1. The second bonding solution is usually used at a solid content concentration of 5 to 20% by weight.

Next, an example of a 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 was pelletized under vacuum conditions of -760 mmHg or less for 100
Dry at a temperature of 200C for 2 hours or more, usually 4 to 48 hours.

Next, the polyphenylene sulfide resin is dissolved, preferably by 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 insulation tube or a heating tube in which the atmosphere between 30 cm is 200 to 350 ° C., 10
Cool with warm air of 0 ° C or less.

As the high-temperature atmosphere provided immediately below the die, appropriate conditions are selected according to the melt flow rate (MFR) of the polymer, the fiber of the yarn and the spinning speed.

Subsequently, the spun yarn is uniformly cooled and solidified with hot air or cold air at a temperature of 100 ° C. or less, preferably 20 to 80 ° C., and after the oil agent (treatment agent) is attached, the spun yarn 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 the hot drawing step continuously without being wound, and is usually subjected to multistage drawing of two or more stages. The draw ratio depends on the spinning conditions,
It is 3-5.5 times, preferably 3.5-5 times. In the case of using two-stage stretching, the first-stage stretching is performed at 70% or more of the total magnification, usually 75 to 85%, and the rest is performed in the second-stage 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. However, 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 subjected to a relaxation heat treatment with a relaxation roll and then wound up. 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.

On the other hand, for example, the intrinsic viscosity (IV) obtained by high-speed melt-spinning and drawing of polyethylene terephthalate
A raw cord is obtained by twisting a polyester fiber thread having a denier of 1.05, a strength of 8.5 g / d and a denier of 1000 with a twist of about 8 times / 10 cm.

Next, the above-mentioned twisted cord of the above-mentioned polyphenylene sulfide fiber yarn and the above-mentioned twisted cord of the polyester fiber yarn are twisted, for example, in a direction opposite to the direction of the twisting by about 8 times / 10 cm. By twisting with
Get the raw code.

The synthetic synthetic fiber cord for rubber reinforcement of the present invention is
In particular, when used as a reinforcing material for brake hoses and cooler hoses, adhesion to ethylene / propylene / diene terpolymer rubber (hereinafter, EPDM) is important.
By applying the following first treatment liquid and second treatment liquid to the raw cord, it is possible to particularly improve the adhesiveness to EPDM.

As the first adhesive treatment liquid, for example, a polyepoxide compound / blocked isocyanate compound / vinylpyridine-styrene-butadiene copolymer latex in a solid content ratio of 11.0% by weight / 23% by weight / 66.0% is used.
A silicate compound (SiO ₂ / Al ₂ O ₃ / M
_{gO / Na 2 0 / Li 2} O / F ( weight ratio) = 54.5 /
0.19 / 27.2 / 5.8 / 1.1 / 2.9, about 95 parts by weight of an aqueous solution having a transmittance of 95% and a thixotropy index of 8.9) were added thereto. 6% by weight
Use the one that has been adjusted.

As the second adhesive treatment liquid, for example, the following R
FL is used.

In the presence of an alkali catalyst, resorcinol and formalin are mixed at a molar ratio of about 2/3, and aged for about 2 hours to obtain an initial condensate having a solid content of about 10% by weight. A styrene-butadiene copolymer latex (VP latex) and a polybutadiene latex (BR latex) are mixed at a ratio of about 50/50 solids weight, and about 12.5 parts by weight are mixed with about 100 parts by weight of a mixed latex. After 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 first bonding solution using a computer treater (manufactured by Ritzler), dried at about 150 ° C. for about 2 minutes, and subsequently at about 240 ° C. for about 1 minute. After the heat treatment, it is further immersed in the second adhesive treatment liquid, dried at about 150 ° C. for about 2 minutes, and subsequently heat-treated at about 240 ° C. for about 1 minute, and then the obtained processing cord is wound up by a winder. Thereby, the synthetic fiber cord for rubber reinforcement of the present invention can be obtained.

Here, it is possible to prevent the RFL from adhering to the roller without solidifying and to reduce the amount of adhering to the cord, and also to prevent the adhesion to the rubber from being deteriorated due to the uneven adhesion and the blister. From the viewpoint of preventing generation of (scum), the drying temperature after the treatment with the first bonding treatment liquid is 70.
Temperatures of １５０150 ° C. are preferred. From the viewpoint of preventing RFL from deteriorating while lowering the adhesiveness with rubber while preventing the RFL from deteriorating, the heat treatment temperature after the treatment with the first adhesive treatment liquid and drying is performed. A range from 200 to 255 ° C is preferred.

From the same viewpoint, the drying temperature after the treatment with the second adhesive treatment liquid is preferably 70 to 150 ° C., and the heat treatment temperature is preferably 200 to 255 ° C.

On the other hand, if the heat treatment temperature is lower than 200 ° C., it is not preferable because the adhesion to rubber is reduced.

The amount of the first adhesive treatment liquid attached to the synthetic fiber cord is in the range of 1.0 to 3.5% by weight, more preferably 1.2 to 2.5% by weight in terms of solid content. (2) The adhesion amount of the adhesive treatment liquid is preferably in the range of 1.0 to 3.5% by weight, more preferably 1.2 to 2.5% by weight. It is preferable that the sum of the solid content of the second adhesive treatment liquid is 2.0 to 4.0% by weight.

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

The rubber reinforced with the synthetic fiber cord for rubber reinforcement 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 when applied to rubber hoses for automobiles, especially brake hoses, cooler hoses, radiator hoses or power steering hoses.

[0097]

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

The 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.

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

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

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

[Code 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.

[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.

[Treatment liquid adhesion amount] JIS L 1017
(1995) by the dip pickup-mass method.

[Treatment Cord Adhesion] <Rubber 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 Tetramethylthiuram disulfide 1.0 A test piece having a width of 25 mm was prepared using the compounded rubber and the treated cord, and the treated cord / rubber peeling force was measured according to the peeling test method described in JISK 6328 (1995). . That is, after unvulcanized rubber is pasted on an aluminum pipe having a diameter of 10 cm and a length of 6 cm, a wrapping cloth (35 mm, manufactured by Toray Industries, Inc.) is wound and vulcanized at 150 ° C. for 30 minutes using an autoclave. , JIS
Treatment code according to the peel test method described in K 6328
The rubber peeling force was measured.

[Steam resistance] A treated cord was placed in an autoclave and heat-treated with steam at 150 ° C. for 24 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 wet heat treatment / cord strength before wet heat treatment) × 100.

[Steam Heat Resistance in Rubber] A rubber having the following composition is vulcanized to produce a rubber sheet having a thickness of 1.0 mm. Next, the treatment cord is sandwiched between the rubber sheets, and treated with steam at 150 ° C. for 15 hours in an autoclave. Next, the cord was taken out from the rubber, the cord strength before and after the treatment was measured, and the strength retention obtained by the following equation was defined as the steam heat resistance in the rubber. Strength retention (%) = (cord strength after wet heat treatment / cord strength before wet heat treatment) × 100.

[Brake fluid resistance (DOT # 3)] 120
Commercially available automotive brake fluid heated to ℃ (DOT # 3)
The treated cord was immersed in the bath for 264 hours, and the strength before and after the treatment was measured. Strength retention (%) = (cord strength after immersion / cord strength before immersion) × 100 [Brake fluid resistance (DOT # 4)] A commercially available automotive brake fluid (DOT # 4) heated to 120 ° C. The treated cord was immersed in a bath for 72 hours, and the strength before and after the treatment was measured.
T # 4). Strength retention (%) = (cord strength after immersion / cord 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, 1.6% of a non-aqueous treating agent containing 3.5% by weight of an antioxidant was applied to the yarn passed through the cooling zone, and the yarn was taken up at 700 m / min. The heat treatment was performed on a heating roller, and the film was stretched in three stages at a total stretching ratio of 4.3 times.

Then, the yarn was continuously heat-treated at a relaxation rate of 3% and wound up to obtain a denier 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 74.8 g. / D, 180 ° C dry heat shrinkage 5.8
%, A polyphenylene sulfide filament fiber yarn having hardly any oligomers of less than hexamer, insoluble matter and bubbles in the fiber was obtained.

Four polyphenylene sulfide fiber yarns (hereinafter referred to as PPS fiber yarns) thus obtained were aligned and twisted with a twisting machine so that the number of twists was 8 T / 10 cm, to obtain a sub-twisted cord. .

On the other hand, an intrinsic viscosity (IV) of 1.0 obtained by high-speed melt spinning and stretching of polyethylene terephthalate was obtained.
5. Eighteen / 10 polyester fiber yarns (hereinafter referred to as PET fiber yarns) having a raw yarn strength of 8.5 g / d and a denier of 1000
The raw cord was obtained by twisting with a twist number of cm.

Next, the ply-twisted cord of the polyphenylene sulfide fiber yarn and the ply-twisted cord of the polyester fiber yarn are mixed-twisted in a direction opposite to the direction of the ply twist at a twist number of 8/10 cm. , Got the raw code.

The first adhesive treatment liquid was obtained by dissolving the polyepoxide compound in water and adjusting the solid content to 6%.

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. Butadiene copolymer latex (VP latex) and polybutadiene latex (B
R latex) and 100 parts of a mixed latex mixed at a solids weight ratio of 50/50, and 12.4 parts were mixed and aged for 24 hours to obtain a 30% solids RF.
L was prepared. Next, a chlorophenol-based compound “Denabond” (manufactured by Nagase Kasei Co., Ltd.) was added to the RFL.
5% was added, and the solid content was adjusted to 15% with water. Further, by diluting this with water, the second solid having a solid concentration of 10% can be obtained.
An adhesive treatment liquid was prepared.

Next, the first adhesive treatment liquid was applied to the raw cord using a computer treater (manufactured by Ritzler), and draining was performed with an air wiper.
Drying was performed at 20 ° C. for 100 seconds, followed by heat treatment at 240 ° C. for 60 seconds.

Further, the second adhesive treatment liquid was applied in the same manner as described above, dried at 120 ° C. for 100 seconds, and subsequently heat-treated at 240 ° C. for 60 seconds.

The adhesiveness of the cord thus obtained,
Evaluates steam resistance, steam resistance in rubber, and brake fluid resistance,
The results are shown in Table 1. As is evident from the results in Table 1, the synthetic fiber cord for rubber reinforcement of the present invention has good adhesiveness with the rubber to be adhered, and furthermore, has resistance to steam heat, steam heat resistance in rubber, brake fluid and the like. The durability is remarkably improved, and it is useful as a reinforcing material for brake hoses and cooler hoses.

[0121]

[Table 1] (Example 2) A polyepoxide compound / blocked isocyanate compound / vinylpyridine-styrene-butadiene copolymer latex having a solid content ratio of 11.0% / 23
% Of a mixture obtained by mixing at a ratio of 66.0% with respect to 100 parts of a silicate compound (SiO2 / Al203 / MgO).
/ Na2 0 / Li2 O / F = 54.5 / 0.19 / 2
6 parts of an aqueous solution of 7.2 / 5.8 / 1.1 / 2.9, transmittance: 95%, thixotropic index: 8.9) were added,
By setting the solid content of the mixed solution to 6%, a first adhesive treatment liquid was obtained.

The same operation as in Example 1 was performed except that this second adhesive treatment liquid was used, and the evaluation results of the obtained codes are also shown in Table 1.

(Examples 3 and 4) All operations were carried out in the same manner as in Example 2 except that the twist ratio of the polyphenylene sulfide fiber yarn and the polyester fiber yarn was changed as shown in Table 1. Table 1 also shows the evaluation results of the codes.

(Comparative Examples 1 to 4) The same operation as in Example 2 was carried out except that the twist ratio of the polyphenylene sulfide fiber yarn and the polyester fiber yarn was changed as shown in Table 2, and the results were obtained. Table 2 shows the evaluation results of the codes.

[0125]

[Table 2] As is evident from the results in Table 2, the synthetic fiber cord for rubber reinforcement of the present invention has good adhesiveness with the rubber to be adhered, and furthermore, has a steam heat resistance, a steam heat resistance in rubber, a brake fluid and the like. The durability is remarkably improved, and it is useful as a reinforcing material for brake hoses and cooler hoses.

[0126]

The synthetic fiber cord for rubber reinforcement of the present invention is
It has good adhesion to rubber, significantly improved steam resistance and chemical resistance, and is excellent in fiber strength retention and durability.

Therefore, the synthetic fiber cord for rubber reinforcement of the present invention makes use of its excellent properties to provide a tire cord,
Can be used to reinforce various reinforcing rubber products such as power transmission belts, conveyor belts and rubber hoses, especially when applied to automotive rubber hoses, especially brake hoses, cooler hoses, radiator hoses or power steering hoses. Demonstrate the ideal performance.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI D06M 15/41 D06M 15/41 15/693 15/693 // C08J 5/06 CEQ C08J 5/06 CEQ D01F 6/76 D01F 6/76 D D06M 101: 32

Claims (6)

[Claims] 1. A cord in which a polyphenylene sulfide fiber yarn and a polyester fiber yarn are twisted,
A synthetic fiber cord for rubber reinforcement, wherein the fineness ratio between the polyphenylene sulfide fiber yarn and the polyester fiber yarn is 3/7 to 7/3. 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 rubber-reinforced synthetic fiber cord according to 2. 4. A polyphenylene sulfide fiber yarn and a polyester fiber yarn are twisted and treated with a first adhesive treatment solution containing a polyepoxide compound, and then a mixture of a resorcinol-formaldehyde precondensate and a rubber latex is further contained. A method for producing a synthetic fiber cord for rubber reinforcement, characterized by treating with a second bonding treatment liquid. 5. The method according to claim 4, wherein the treatment is carried out using a first adhesive treatment liquid containing a polyepoxide compound, a blocked isocyanate and / or an ethylene urea compound, a rubber latex and a silicate compound as an adhesive component. A method for producing the synthetic fiber cord for rubber reinforcement according to the above. 6. The process for producing a synthetic fiber cord for rubber reinforcement according to claim 4, wherein the treatment is carried out using a second adhesive treatment solution containing a chlorophenol compound.