JP2001234479A - Treated fiber for reinforcing rubber having tackiness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fabric or a yarn having the surface subjected to a coating treatment with a new resocinol-formalin-formaldehyde(RFL) composition having the tackiness. SOLUTION: This fabric or yarn for reinforcing rubber is characterized in that the surface of a fiber is treated with the RFL composition containing an emulsion of a tackifier. A bead tape or a lapping cord obtained by carrying out the coating treatment of the fiber surface with the RFL composition containing the emulsion of the tackifier has good adhesion while holding excellent tackiness and moderate hardness. When the treated fiber is used as the bead tape, folded back from the inner peripheral side to the outer periphery of bead wires and wound around the bead wires, the bead tape having high operating efficiency due to the moderate hardness without wrinkles due to sufficient tackiness and resultantly without causing unevennesses on the tire inner peripheral surface is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber reinforcing fabric or thread used as a reinforcing material for rubber products such as tires and rubber hoses, and more particularly to a bundled fabric or thread for a bead wire of a pneumatic tire. It is about.

[0002]

2. Description of the Related Art A bead wire for a tire is formed by turning a single wire or a plurality of wire strands a plurality of times together with an unvulcanized coated rubber, and particularly a so-called strand bead is generally used. With these bead wires,
Conventionally referred to as bead tape because of the workability at the time of tire molding, particularly the problem of adhesion at the time of press bonding to the carcass layer, and more importantly, the problem that the bead wire is deformed during vulcanization of the tire and the shape of the bead wire is disturbed. The outer circumference of the bead wire is tightened with a non-vulcanized rubber-coated organic fiber plain cloth to improve the adhesion and prevent the bead wire from being deformed during tire vulcanization. .

[0003] The bead tape is generally composed of a plain woven fabric having a driving density of 10 to 100 threads / 5 cm each for a warp and a weft, and this plain woven fabric is once dipped in an RFL solution and then dried. This dip plain woven fabric further adheres a rubber cement obtained by dissolving unvulcanized rubber in the form of a rubber paste with an organic solvent on the dip plain woven fabric in order to improve adhesiveness, and immediately thereafter, is squeezed by two rollers, Next, it is dried and the warp and the weft are covered with the unvulcanized rubber. The plain woven cloth covered with the rubber layer is cut into a predetermined width and used as a bead tape of a bead wire (for example, see Japanese Unexamined Patent Publication No.
No. 2-121039).

[0004]

The bead tapes for bead wires that have been used conventionally have useful properties, but the following improvements are required. First, the plain woven fabric is once dipped with an RFL solution, and then coated with a rubber cement in which unvulcanized rubber is dissolved in the form of a rubber paste to improve the adhesiveness. It is easy to progress. Secondly, rubber cement dissolves unvulcanized rubber in the form of a rubber paste with an organic solvent, deposits it on a dip plain woven cloth, and immediately thereafter, is squeezed by two rollers and then dried. The economic costs of maintaining health and maintaining a good work environment are extremely high.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that a bead wire and a bead wire can be formed by coating a fiber surface with an RFL composition containing a tackifier emulsion. For the first time, it was found that when winding a bead tape or a wrapping cord with good adhesiveness, it was possible to obtain a fabric or a yarn having good workability, and the present invention was completed.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The cloth or thread for rubber reinforcement of the present invention is obtained by coating the fiber surface with an RFL composition containing a tackifier emulsion to obtain a fiber having excellent tackiness. The fineness of the warp and the weft of the rubber reinforcing fabric of the present invention is preferably from 44 to 1,400 dtex, particularly preferably 78 to 1400 dtex.
The range of -235 dtex is more preferable. The driving density of the rubber reinforcing fabric of the present invention is such that the warp and the weft are each 10 to 10.
100 pieces / 5 cm is preferred, and especially 20-70 pieces / 5c
The range of m is more preferred. The rubber reinforcing fabric of the present invention is
It includes the form of a knit or a woven fabric.

The fineness of the rubber reinforcing yarn of the present invention is 940 to 940.
2100 dtex is preferable, and especially 1200 to 2100
The range of dtex is more preferable, and 0 to 20 times / 10 cm
Is preferred, and a cord form of 4 to 15 times / 10 cm is particularly preferred. The rubber reinforcing fabric or yarn of the present invention is a long fiber made of multifilament yarn such as nylon 6 or nylon 66, vinylon, polyester, rayon, aromatic polyamide, cotton, etc., monofilament yarn and spun yarn, and / or Short fibers may be used alone or in combination of two or more, and may be used in the form of a woven fabric, a knitted fabric, a braid, a thread, a rope, or a mixture thereof, but more preferably excellent in heat resistance and durability. Preferably, it is made of nylon 66 material.

In the above-mentioned RFL composition, the molar ratio (R / F) of resorcinol (R) to formaldehyde (F) is preferably from 1: 1 to 3, particularly preferably about 1: 2.
Examples of the RFL rubber latex include vinylpyridine-styrene-butadiene copolymer latex (VP latex), styrene-butadiene copolymer latex (SBR latex), butadiene latex (BR latex), and acrylonitrile-butadiene copolymer latex. Coalescing latex (NBR latex), chlorobrene latex (CR latex), chlorosulfonated polyethylene latex (CSM latex), butyl rubber latex (IR latex), acrylate rubber latex and natural rubber latex (NR latex); These can be used alone or in combination of two or more depending on the type of rubber to be adhered.

In particular, NR latex and a mixed latex system of SBR latex and VP latex are preferred. In this case, the solid content of NR latex is 70% or more,
More preferably, the solid content of BR latex is 15% or less, and the solid concentration of VP latex is 15% or less. In the above RFL, the compounding ratio (R) of the resorcinol-formaldehyde precondensate (RF) and the rubber latex (L)
(F / L) preferably has a solid content weight ratio of 1:10 to 80, and more preferably 1:10 to 40. When the solid content weight ratio of the rubber latex is less than 1:10, the treated fabric or yarn tends to be hard and the processability tends to be deteriorated. The fabric or yarn is too soft, and the processability tends to be poor, and the adhesiveness to the adhered rubber tends to be poor, which is not preferable.

In the present invention, the surface of the fiber is coated with a composition containing a tackifier emulsion in addition to the RFL solution, so that a fabric or thread having excellent tackiness can be obtained. Examples of the tackifier emulsion include an alkyl petroleum resin, a terpene phenolic resin, a hydrogenated rosin ester, a polymerized rosin ester, a t-butyl phenol resin, and the like. Can be

[0011] The tackifier emulsion in the RFL composition is preferably 2 to 15% by weight based on the solid content of the RFL, and particularly 4 to 10% by weight of the treated fabric or yarn in the tackiness and softness. Good adhesiveness and adhesion to rubber to be adhered. The amount of adhesion of the RFL composition of the present invention is 5 to 70% by weight in terms of solid content based on the fabric or yarn before treatment.
It is particularly preferable in terms of tackiness, flexibility and quality of the fabric treated in the range of 10 to 55% by weight or the yarn treated in the range of 5 to 8% by weight. 5 by solids weight
When the amount is less than 70% by weight, the adhesiveness of the fabric or the yarn is remarkably poor. When the amount exceeds 70% by weight of the solid content, the RFL composition does not adhere and adheres to the rollers in the processing step, and the fabric or the yarn is removed. Adhesion of the strips tends to occur, and the adhesiveness to the adhered rubber tends to deteriorate.

The method for coating the surface of the bead tape of the present invention will be described with reference to examples. Nylon 66 fineness 78dtex / 2 for warp and nylon 66 fineness 78d for weft
warp density using tex / 2 threads 26 threads / 2.54 cm ×
A warp knit having a weft density of 32 yarns / 2.54 cm is immersed in the composition containing the tackifier emulsion, and
After drying at a temperature of ~ 130 ° C for 20 ~ 50 seconds, 170 ~ 2
Heat set at a temperature of 10 ° C. for 60-90 seconds.

When the drying temperature is lower than 90 ° C., the RFL composition does not adhere and adheres to the rollers during the processing step, and the amount of the adhesion decreases and the adhesion unevenness of the fabric or the yarn occurs. Tends to have poor adhesion. When the temperature exceeds 130 ° C., blisters are easily generated, which is not preferable. When the heat setting treatment temperature is lower than 170 ° C., the tackiness is hardly developed, and the adhesion to the adhered rubber tends to be deteriorated. 210 ° C
If it exceeds, the adhesiveness of the fabric or yarn is too strong, so that post-processing such as slitting becomes difficult, and moderate flexibility tends to be impaired.

The rubber reinforcing cloth or yarn treated with the RFL liquid composition containing the tackifier emulsion of the present invention may be, for example, natural rubber (NR), styrene-butadiene rubber (SBR), chlorobrene rubber (CR) , Ethylene propylene rubber (EPDM), nitrile rubber (NBR),
Hydrogenated nitrile rubber (HNBR), chlorosulfonated polyethylene rubber (CSM), butyl rubber (IIR), acrylic rubber (ACM), chlorinated polyethylene rubber (CP
When E) and a mixture of these various rubbers are used as the adhered rubber, the effect is exhibited, but the type of the rubber is not particularly limited.

Next, the configuration and effects of the present invention will be described more specifically with reference to examples. Each measurement result in the following examples was obtained by the following method.

(1) Adhesiveness <In the case of cloth> The treated cloth is 35 mm wide and 150 mm long.
Prepared 6 sheets, cut and stacked, and pressed 1.96
Pressure was applied at 2 MPa for 2 minutes to determine the maximum stress at the time of peeling between the third and fourth sheets, and the value was regarded as the adhesiveness of the treated cloth. <In the case of yarn> Width 10 of 40 processed yarns aligned
4 samples of 150 mm in length and 150 mm in length are prepared, stacked and pressed by a press at 0.96 MPa for 2 minutes, and the maximum stress at the time of peeling between the second and third sheets is determined. The adhesiveness of the strip.

(2) Hardness <In the case of cloth> The treated cloth is 2.54 cm wide and 5 cm long.
When placing the treated cloth at right angles on a bridge (3 mmφ wire placed in parallel at 3 cm intervals) on a bridge of a tensile tester, hooking a hook bar (3 mmφ) at the center, and pulling out vertically between the bridges Was determined and the value was taken as the hardness of the treated cloth. The speed at which the hook bar is moved is 100 mm / min. <In the case of yarn> A treated yarn having a length of 3.81 cm is prepared, and its bending resistance is measured using a Gurley tester according to the bending resistance (Gurley method) described in JIS L 1096 (1999). It was measured.

(3) Adhesive force <In the case of cloth>
A test piece of 4 cm was prepared and subjected to JIS K6404-5.
The peeling force between the treated cloth and the rubber to be adhered was measured according to the adhesion test (adhesion strength ... test method B) described in (1999). Vulcanization was performed at 150 ° C. for 20 minutes using a vulcanizing press. <In the case of yarn> Using the adhered rubber and treated yarn, JIS
The pull-out adhesive force between the treated yarn and the adhered rubber was measured according to the adhesive force-T test (Method A) described in L-1017 (1995). Vulcanization was performed at 150 ° C using a vulcanizing press.
Performed for 0 minutes.

(4) Suitability of bead tape and wrapping cord The above measurement results were comprehensively evaluated, and the most suitable bead tape and wrapping cord in terms of adhesion and workability were evaluated as ◎, and the most suitable as ○. , And unsuitable ones were marked x.

[0020]

Example 1 Resorcinol and formalin were mixed at a molar ratio of 1/2 in the presence of an alkali catalyst and aged for 20 minutes to obtain an RF solution having a solid content of 8%. NR latex and S
BR latex and VP latex were added at a solid content weight ratio of 87:
The mixed latex (L) mixed at a ratio of 2:11 is RF
The RF solution and water were mixed so that the / L solid content weight ratio was 1:39, and after aging for 18 hours, ammonia was added,
An RFL solution having a solid content of 30% was prepared. An alkyl petroleum resin “Cerosol A-43-C” (manufactured by Chukyo Yushi Co., Ltd.) was added to this RFL solution as a tackifier emulsion.
An FL solid content ratio of 6.5% was used. On the other hand, fineness 7
Using a Russell knitting machine, a nylon 66 yarn of 8 dtex is used with a warp density of 36 courses / 2.54 cm and a weft density of 12 wales /
Knitting was performed at 2.54 cm to obtain a marquisette knitted fabric.

Next, the RFL liquid composition was immersed in a Marquisette knitted fabric using a non-touch drier,
At 32 ° C. for 32 seconds, followed by 7 minutes at 190 ° C. using a clip tenter at an overfeed rate of 10%.
After heat setting for 2 seconds, the resulting treated cloth was wound up on a winder. Table 1 shows the results of evaluating the tackiness, hardness, adhesiveness, and the like of the treated cloth.

[0022]

Example 2 The same treatment as in Example 1 was performed except that the amount of the tackifier was changed as shown in Table 1, and the resulting treated cloth was evaluated for tackiness, hardness, adhesiveness, and the like. The results are shown in Table 1.

[0023]

Examples 3 to 6 Resorcinol and formalin were mixed at a molar ratio of 1/2 in the presence of an alkali catalyst and aged for 6 hours to obtain an RF solution having a solid content of 6.5%. Table 1 shows RF / L solid content weight ratio, latex compounding ratio, and tackifier addition amount.
Table 1 and Table 2 also show the results of evaluating the tackiness, hardness, adhesiveness, and the like of the obtained treated cloth, except that the treatment was performed as described in Example 1.

[0024]

Example 7 An RFL liquid composition containing the same tackifier emulsion as in Example 1 was prepared. On the other hand, fineness 23
One 5dtex nylon 66 thread 15 times / 1 in the S direction
Using a warp yarn twisted with a twist of 0 cm and a non-twisted weft yarn of one nylon 66 yarn having a fineness of 235 dtex, a plain fabric having a driving density of 52.5 yarns / 5 cm was obtained. Next, the RFL liquid composition is immersed in the plain fabric using a non-touch drier and dried at 100 ° C. for 32 seconds, and subsequently at 190 ° C. for 72 seconds under a condition of an overfeed rate of 5% using a clip tenter. After heat setting, the obtained treated cloth was wound up on a winder. The tackiness of this treated cloth,
Table 3 shows the results of evaluation of hardness, adhesiveness, and the like.

[0025]

Example 8 An RFL liquid composition containing the same tackifier emulsion as in Example 1 was prepared. On the other hand, fineness 14
One nylon 66 thread of 00dtex 10 times / 10cm
To obtain a twisted yarn. Next, the RFL liquid composition was immersed in the yarn using a computer treater (manufactured by Ritzler), dried at 120 ° C. for 129 seconds, and subsequently heat-treated at 200 ° C. for 61 seconds. Table 4 shows the results of evaluating the tackiness, hardness, adhesiveness, and the like of the treated yarn.

[0026]

Comparative Example 1 Resorcin and formalin were mixed at a molar ratio of 1/2 in the presence of an alkali catalyst and aged for 6 hours to obtain an RF solution having a solid content of 6.5%. NR latex, SBR latex and VP latex were mixed at a solid content weight ratio of 5:
The mixed latex (L) mixed at a ratio of 15:80
The RF solution and water are mixed so that the F / L solid content weight ratio is 1: 5, and after aging for 30 minutes, ammonia is added.
An RFL solution having a solid content of 16% was prepared. This RFL solution was immersed in the same marquisette knitted fabric as in Example 1, and thereafter the same treatment as in Example 1 was performed. The results of evaluating the tackiness, hardness, adhesiveness, and the like of the obtained treated cloth are shown in Table 5. It was shown to.

As is evident from the measurement results in Table 5, the treatment cloth using the RFL solution of Comparative Example 1 which is generally used had low adhesiveness and was unsuitable as a bead tape. RF / L solid content weight ratio of Examples 1 to 6 1/39 to 1
As shown in Tables 1 and 2, the treated cloth using the RFL liquid composition of No. 0 was suitable as a bead tape in terms of hardness, tackiness and adhesive strength. Example 7 in Table 3 shows the hardness, adhesiveness, and the like of the plain-woven cloth using the same RFL liquid composition as in Example 1.
The adhesive strength was suitable as a bead tape. In Example 8, the hardness, adhesiveness and adhesive strength of the treated cord using the same RFL liquid composition as in Example 1 were suitable as a wrapping cord.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

[0031]

[Table 4]

[0032]

[Table 5]

[0033]

As described above, the bead tape or the wrapping cord (Examples 1 to 8) obtained by coating the fiber surface with the RFL liquid composition containing the tackifier emulsion of the present invention, Compared to a conventional vinylon plain woven fabric obtained by rubber cementing unvulcanized rubber, it has good adhesive strength while maintaining excellent tackiness and moderate hardness.

When the treated cloth of the RFL composition containing the tackifier emulsion of the present invention is used as a bead tape of a bead wire and is wound from the inner peripheral side to the outer peripheral side of the bead wire, the adhesiveness is sufficient. There is no unevenness on the inner peripheral surface of the tire as a result, and a bead tape having high workability can be obtained because of appropriate hardness.

Claims (5)

[Claims] 1. A rubber-reinforcing fabric comprising a mixture of a resorcinol-formaldehyde precondensate and a rubber latex (hereinafter referred to as RFL) as a main component and a surface coated with an RFL composition containing a tackifier emulsion, or Thread. 2. The rubber reinforcing cloth or yarn according to claim 1, wherein the tackifier emulsion in the RFL composition is 2 to 15% by weight based on the solid content of the RFL. 3. The R / F molar ratio of the RFL composition is 1:
3. The rubber reinforcing cloth or yarn according to claim 1, wherein the weight ratio of RF / L solids is 1:10 to 80. 4. The rubber reinforcement according to claim 1, wherein the amount of the RFL composition adhered to the cloth is 5 to 70% based on the weight of the base cloth. Fabric or yarn. 5. The rubber reinforcing fabric or thread according to claim 4, which is used as a bead tape or a wrapping cord for a bead wire of a pneumatic tire.