JP2007045137A - Rubber product, its manufacturing process, wrapped body for wrapping cure and wrapping cloth for wrapping cure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture high quality rubber product by wrapping cure. <P>SOLUTION: A cloth made of polyketone fibers is used as a wrapping cloth employed in the manufacture of a rubber product by wrapping cure in which an uncured rubber-formed body clamped with clamping force applied to it with the wrapping cloth is cured. Since a polyketone fiber has excellent heat resistance and durability, remains unchanged in the properties after repeated use for wrapping cure, does not cause the deterioration of the appearance, such as wrinkles on the surface, of the cured product and thus can be used repeatedly for a long period of time. Since a polyketone fiber has excellent heat shrinkability in the cure temperature region, the wrapping cloth made of polyketone fibers gives pressure sufficient to restrain the foaming of the rubber during curing, to thereby enhance rubber properties. When different materials are bonded together during vulcanization, the use of the wrapping cloth produces a rubber product having the good adhesion between the different materials. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rubber product by lapping vulcanization, a method for producing the same, a wound body for lapping vulcanization, and a fastening cloth for lapping vulcanization.

  When vulcanizing molded products of unvulcanized rubber to produce various rubber products, it is possible to suppress foaming of rubber during vulcanization, improve rubber physical properties, and to bond and integrate dissimilar materials during vulcanization. When performing, it is necessary to give a pressurizing force to the molded body of unvulcanized rubber for the purpose of improving the adhesiveness.

  Conventionally, as a method for applying pressure to a molded body of unvulcanized rubber during vulcanization, a tightening cloth (not limited to a cloth-like material made of fiber woven fabric) may be a twisted cord on the outer periphery of the unvulcanized rubber. Hereinafter, there is a wrapping vulcanization method in which these are referred to as “wrapping cloth” and heated and vulcanized. In this method, a large fastening force can be obtained and the pressurizing effect can be enhanced by wetting the wrapping cloth with water and then winding the wrapping cloth around an unvulcanized rubber molded body.

  With such a lapping vulcanization method, a hot water vulcanization method in a vulcanization can (a vulcanization method in which hot water is immersed in a vulcanization can and pressurized and heated with steam) or a steam vulcanization method (vulcanization) Because it is possible to perform sufficient pressurization and heating only by heating with hot air in the oven, without the need for a vulcanization can as in the case of vulcanization method that directly pressurizes and heats with steam in the can. There is an advantage that equipment costs can be greatly reduced.

  Conventionally, as a wrapping cloth used in this wrapping vulcanization, a fiber fabric made of nylon has been used.

However, the conventional wrapping cloth made of nylon fibers has the following drawbacks.
(1) There is a problem in durability of repeated use. That is, when the nylon fiber is repeatedly used, the fiber characteristics change, and the appearance of the product is impaired due to wrinkles on the surface of the product after vulcanization. For this reason, there is a limit to the number of times it can be used repeatedly.
(2) The tightening force by the wrapping cloth is not sufficient, and the effect of suppressing foaming of rubber during vulcanization, improving the physical properties of rubber, and improving the adhesion between different materials cannot be obtained sufficiently.

  The present invention solves the problems of the above-mentioned conventional nylon fiber wrapping cloth, is excellent in durability, has little change in fiber properties due to repeated use, and therefore has a long repeated use life and is vulcanized with high clamping force. By using a wrapping cloth that gives sufficient pressure to the unvulcanized rubber molded product in the interior to sufficiently suppress foaming, improve physical properties of rubber, and improve adhesion, An object is to provide a method for producing an excellent rubber product.

  Another object of the present invention is to provide a wrapping body for wrapping vulcanization, a rubber product obtained from the wrapping body for wrapping vulcanization, and a fastening cloth for wrapping vulcanization.

  As a result of intensive studies to solve the above problems, the present inventors pay attention to the excellent heat resistance and large heat shrinkage stress of the polyketone fiber, and can solve the above problem by using the polyketone fiber as a wrapping cloth material. I found out.

（（Ｉ）式中、Ｒはエチレン性不飽和化合物由来の連結基であり、各繰り返し単位において、同一であっても異なっていても良い。）
［３］ ［２］において、前記一般式（Ｉ）において、Ｒの８０モル％以上がエチレン由来の連結基であることを特徴とするゴム製品の製造方法。
［４］ ［２］又は［３］において、前記ポリケトンの重合度が、ｍ−クレゾール中、６０℃で測定した溶液粘度が１．０〜１０．０ｄＬ／ｇの範囲となる重合度であることを特徴とするゴム製品の製造方法。
［５］ 未加硫ゴムの成形体と、該未加硫ゴムの成形体の外周に巻き付けられた繊維織物及び／又は繊維の撚りコードとを備えるラッピング加硫用巻付体において、該繊維織物及び／又は繊維の撚りコードがポリケトン繊維を含むことを特徴とするラッピング加硫用巻付体。
［６］ ［５］に記載されるラッピング加硫用巻付体を加熱して未加硫ゴムを加硫した後、前記繊維織物及び／又は繊維の撚りコードを取り去って得られることを特徴とするゴム製品。
［７］ 未加硫ゴムの成形体をラッピング加硫する際に、該未加硫ゴムの成形体の外周に巻き付けるための締め付け布であって、ポリケトン繊維の織物よりなることを特徴とするラッピング加硫用締め付け布（即ち、ラッピングクロス）。 The present invention has been achieved on the basis of such knowledge, and the gist thereof is as follows.
[1] A fiber woven fabric and / or a fiber twist cord is wound around the outer periphery of a molded body of unvulcanized rubber, and the unvulcanized rubber is molded while applying a tightening force by the fiber woven fabric and / or fiber twist cord. A process for producing a rubber product by heating a body to vulcanize the unvulcanized rubber, wherein the fiber fabric and / or the twisted cord of the fiber contains a polyketone fiber.
[2] A method for producing a rubber product according to [1], wherein the polyketone fiber is a polyketone fiber represented by the following general formula (I).

(In the formula (I), R is a linking group derived from an ethylenically unsaturated compound, and each repeating unit may be the same or different.)
[3] A method for producing a rubber product according to [2], wherein in the general formula (I), 80 mol% or more of R is a connecting group derived from ethylene.
[4] In [2] or [3], the polymerization degree of the polyketone is a polymerization degree such that the solution viscosity measured in m-cresol at 60 ° C. is in the range of 1.0 to 10.0 dL / g. A method for producing a rubber product.
[5] A wrapping wrapping body for lapping vulcanization comprising a molded body of unvulcanized rubber and a fiber fabric wound around the outer periphery of the molded body of unvulcanized rubber and / or a twisted cord of the fiber. And / or a wrapping body for lapping vulcanization, wherein the twisted cord of the fiber contains polyketone fiber.
[6] The wrapping wrapping body for wrapping vulcanization described in [5] is heated to vulcanize unvulcanized rubber, and then obtained by removing the fiber woven fabric and / or the fiber twist cord. Rubber products.
[7] A wrapping cloth for wrapping around an outer periphery of a molded body of unvulcanized rubber when wrapping and vulcanizing a molded body of unvulcanized rubber, and comprising a woven fabric of polyketone fibers Tightening cloth for vulcanization (ie wrapping cloth).

  In the present invention, the fiber woven fabric and / or the fiber twisted cord as the wrapping cloth is wound around the outermost periphery of the unvulcanized rubber molded product, and after vulcanization, it is removed as a product. It does not remain in rubber products. Therefore, it is clearly distinguished from fiber fabrics and fiber cords for reinforcing rubber products.

  Since the polyketone fiber is excellent in heat resistance and durability, the fiber characteristics hardly change even when it is repeatedly used for lapping vulcanization. For this reason, it does not cause appearance deterioration such as wrinkles on the surface of the product after vulcanization, and can be used repeatedly over a long period of time.

  Moreover, since the polyketone fiber has a high heat shrinkage stress in the vulcanization temperature region, according to the rubber product production method of the present invention using a polyketone fiber fiber woven fabric and / or a twisted cord as a wrapping cloth, the polyketone fiber is used during vulcanization. By applying sufficient pressure to the unvulcanized rubber molded body with a wrapping cloth made to suppress foaming, improve rubber physical properties, and when integrating different materials during vulcanization, A rubber product having excellent adhesion between different materials can be obtained.

（（Ｉ）式中、Ｒはエチレン性不飽和化合物由来の連結基であり、各繰り返し単位において、同一であっても異なっていても良い。） In the present invention, the polyketone fiber is preferably a polyketone fiber represented by the following general formula (I) (Claim 2). In the general formula (I), 80 mol% or more of R is an ethylene-derived linking group. (Claim 3).

(In the formula (I), R is a linking group derived from an ethylenically unsaturated compound, and each repeating unit may be the same or different.)

  Moreover, it is preferable that the polymerization degree of this polyketone is a polymerization degree in which the solution viscosity measured at 60 degreeC in m-cresol becomes the range of 1.0-10.0 dL / g (Claim 4).

  Hereinafter, embodiments of the present invention will be described in detail.

  First, the polyketone fiber used as a constituent material of the wrapping cloth in the present invention will be described.

（（Ｉ）式中、Ｒはエチレン性不飽和化合物由来の連結基であり、各繰り返し単位において、同一であっても異なっていても良い。） The polyketone fiber constituting the wrapping cloth according to the present invention is preferably produced using a polyketone represented by the following general formula (I) as a raw material.

(In the formula (I), R is a linking group derived from an ethylenically unsaturated compound, and each repeating unit may be the same or different.)

  The polyketone is an alternating copolymer in which CO units (carbonyl group) and units derived from an ethylenically unsaturated compound are arranged in the molecule, that is, next to each CO unit in the polymer chain, for example, an ethylene unit, etc. This structure has one olefin unit. The polyketone may be a copolymer of carbon monoxide and one specific ethylenically unsaturated compound, or a copolymer of carbon monoxide and two or more ethylenically unsaturated compounds. Also good.

  Examples of the ethylenically unsaturated compound forming R in the above formula (I) include unsaturated hydrocarbon compounds such as ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, dodecene, styrene, and methyl acrylate. , Methyl methacrylate, vinyl acetate, undecenoic acid and other unsaturated carboxylic acids or derivatives thereof, undecenol, 6-chlorohexene, N-vinylpyrrolidone, and diethyl ester of sulphonylphosphonic acid. These may be used alone or in combination of two or more, but in particular from the viewpoint of the mechanical properties and heat resistance of the polymer, a polyketone using an ethylenically unsaturated compound mainly composed of ethylene Is preferred.

  When ethylene and another ethylenically unsaturated compound are used in combination as the ethylenically unsaturated compound constituting the polyketone, ethylene is preferably used in an amount of 80 mol% or more based on the total ethylenically unsaturated compound. . If this ratio is less than 80 mol%, the melting point of the resulting polymer may be 200 ° C. or lower, and the resulting polyketone fiber may have insufficient heat resistance. In view of the mechanical properties and heat resistance of the polyketone fiber, the amount of ethylene used is preferably 90 mol% or more with respect to the total ethylenically unsaturated compound.

  The polyketone can be produced according to a known method, for example, a method described in European Patent Publication Nos. 121965, 213671, 229408 and US Pat. No. 3,914,391.

  As for the polymerization degree of the polyketone, the solution viscosity measured at 60 ° C. in m-cresol is preferably in the range of 1.0 to 10.0 dL / g. If the solution viscosity is less than 1.0 dL / g, the resulting polyketone fiber may have insufficient mechanical strength. From the viewpoint of the mechanical strength of the polyketone fiber, the solution viscosity is more than 1.2 dL / g. preferable. On the other hand, if the solution viscosity exceeds 10.0 dL / g, the melt viscosity at the time of fiberization and the solution viscosity may become too high, resulting in poor spinnability. From the viewpoint of spinnability, the solution viscosity is 5.0 dL. / G or less is more preferable. In view of the mechanical strength and spinnability of the fiber, the solution viscosity is particularly preferably in the range of 1.3 to 4.0 dL / g.

  The method for fiberizing the polyketone is not particularly limited, but generally a melt spinning method or a solution spinning method is adopted. When adopting the melt spinning method, for example, according to the method described in JP-A-1-124617, the polymer is usually melt-spun at a temperature higher than the melting point by 20 ° C. or more, preferably about 40 ° C. higher than the melting point, Next, it is usually easy to stretch at a temperature lower than the melting point by 10 ° C. or less, preferably about 40 ° C. lower than the melting point, preferably at a stretch ratio of 3 times or more, more preferably at a stretch ratio of 7 times or more. Desired fibers can be obtained.

  On the other hand, when the solution spinning method is adopted, the polymer is added to, for example, hexafluoroisopropanol, m-cresol, etc. in an amount of 0.25 to 20% by mass, preferably 0.5 to Dissolved at a concentration of 10% by mass, extruded from a spinning nozzle to be fiberized, and then removed and washed in a non-solvent bath such as toluene, ethanol, isopropanol, n-hexane, isooctane, acetone, methyl ethyl ketone, preferably in an acetone bath. To obtain a desired filament by drawing at a temperature in the range of (melting point−100 ° C.) to (melting point + 10 ° C.), preferably (melting point−50 ° C.) to (melting point). be able to. In addition, it is preferable to add an antioxidant to the polyketone for the purpose of imparting sufficient durability against heat, oxygen and the like, and if necessary, a matting agent, a pigment, an antistatic agent and the like are also blended. be able to.

  A textile fabric made of such polyketone fibers can be produced with a cord of polyketone fibers. The fineness of the polyketone fiber cord is preferably 150 to 3000 d. If the fineness of the polyketone fiber cord is less than 100 d, the strength is insufficient, and if it exceeds 3000 d, the wrapping cloth becomes so rigid that it is difficult to wind and the cost is also increased.

  The polyketone fiber fabric as the wrapping cloth according to the present invention may be any of plain weave, straight warp weave, twill weave, weave weave, etc., but plain weave or twill weave is usually used.

  The number of cords constituting the polyketone fiber woven fabric varies depending on the thickness of the cord, but usually the warp yarn is 30 to 300/5 cm width, and the weft yarn is 2 to 150/5 cm width. If the number of cords constituting the fiber fabric is too small, it cannot be made a high-strength wrapping cloth that exhibits a sufficient tightening force as a wrapping cloth, and if it is too large, the wrapping cloth has increased rigidity, making it difficult to wind. In addition, the cost increases.

  The textile fabric as a wrapping cloth according to the present invention may be one in which both the warp and the weft are made of polyketone fiber cord, only the warp is made of polyketone fiber cord, and the other is made of other fibers other than polyketone fiber. It may consist of code. The fiber fabric may be composed of a composite fiber cord of polyketone fiber and other fibers, and is a combination of such composite fiber cord and polyketone fiber cord and / or cord of other fibers. There may be. As another fiber, 1 type, or 2 or more types, such as nylon fiber, PET fiber, and aramid fiber, can be used.

  When other fibers are used in combination, it is preferable that 50% by weight or more of the total fiber amount is the polyketone fiber in order to sufficiently obtain the effects of the present invention by using the polyketone fiber.

  The polyketone fiber woven fabric as a wrapping cloth is usually provided as a strip having a width of about 2 to 20 cm.

  In order to produce a rubber product by the wrapping vulcanization method using the wrapping cloth according to the present invention, the wrapping cloth is wound around a molded body of an unvulcanized rubber according to a conventional method and heated to unvulcanized rubber. Can be vulcanized. During this heating, the wrapping body for wrapping vulcanization wrapped with the wrapping cloth may be put in a vulcanizing can and steam vulcanized or hot water vulcanized, but in the present invention, the tightening force by the wrapping cloth is sufficient. Since it is high, hot-air vulcanization in an oven can be performed without using a vulcanizing can.

  The wrapping cloth is preferably wetted in advance before being wound around the unvulcanized rubber molded body, so that a further tightening force can be obtained during vulcanization.

  The vulcanization temperature varies depending on the rubber material used, but is usually about 110 to 160 ° C. The vulcanization time varies depending on the size of the unvulcanized rubber molded product and the vulcanization temperature, but is usually appropriately determined in the range of 20 minutes to 80 hours.

  Such a method for producing a rubber product by lapping vulcanization according to the present invention is effective for producing rubber products such as various hoses, fenders, and rubber dams.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

Examples 1 and 2 and Comparative Examples 1 and 2
As shown in FIG. 1A, an unvulcanized sheet (thickness 3 mm) 2 of SBR (styrene butadiene rubber) 2 is wound around an iron tube 1 having a diameter of 100 mm and a length of 350 mm, and an unvulcanized rubber sheet of natural rubber is wound thereon. (Thickness 3 mm) 3 was wound, and further, as shown in FIG. 1 (b), a wrapping cloth 4 wetted with water was wound spirally while forming an overlap margin.

As wrapping cloth 4,
Warp yarn: 210 denier / 1 piece, number of driven-in 217 pieces / 5 cm width Weft yarn: 210 denier / 1 piece, number of driven-in 90 yarn / 5 cm-wide plain fabric (width 5 cm) is used. The fiber material is as shown in Table 1.

The wrapping body 5 for wrapping vulcanization was vulcanized by the vulcanization method A or B below, and various properties were evaluated by the methods described later. The results are shown in Table 1.
Vulcanization method A: Steam vulcanization at 140 ° C. for 60 minutes in a vulcanizing can Vulcanization method B: Hot air vulcanization at 140 ° C. for 60 minutes in an oven

[Evaluation methods]
Vulcanized rubber properties: Cut out 2mm thick sheets for natural rubber layer and SBR layer.
And tensile strength was measured by the method based on JISK6251.
Interlayer adhesion state: in a state where a natural rubber layer and an SBR layer are laminated, a width of 25 mm and a length of 150
Cut out a strip test piece of mm and peel speed between the natural rubber layer and the SBR layer
Peeled at a rate of 50 mm / min, presence or absence of delamination (rubber failure), delamination
The ratio of the peeled area in the case of
Ratio).
Repeat durability: The wrapping cloth is repeatedly used 10 times for the above wrapping vulcanization.
0th vulcanized rubber surface appearance (wrinkle occurrence) and foaming occurrence
It was observed visually.

From Table 1, the following is clear.
In Comparative Examples 1 and 2 using a nylon fiber wrapping cloth, since the tightening force is not sufficient, the hot air vulcanization is inferior in rubber physical properties compared to steam vulcanization. In addition, the interlayer adhesion is not sufficient, and particularly in the case of hot air drying, the interlayer adhesion is very poor. In addition, the repeated durability is poor, and there are problems of deterioration in surface appearance and foaming.
On the other hand, in Examples 1 and 2 using the polyketone fiber wrapping cloth, a sufficient tightening force can be obtained, so that the natural rubber layer is used not only in the case of steam vulcanization but also in the case of hot air vulcanization. In addition, the tensile strength of the SBR layer is high, and the interlayer adhesion is also high. Moreover, the wrapping cloth made of polyketone fiber is excellent in repeated durability, and after repeated use, a product having good appearance without foaming can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of the lapping vulcanization method in Example 1, 2 and Comparative Example 1, 2, Comprising: Fig.1 (a) is sectional drawing which shows the wound body for lapping vulcanization, FIG.1 (b) It is a perspective view which shows the winding method of a wrapping cloth.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Iron pipe 2 SBR unvulcanized sheet 3 Natural rubber unvulcanized sheet 4 Wrapping cloth 5 Wrapping body for lapping vulcanization

Claims (7)

  A fiber woven fabric and / or fiber twist cord is wound around the outer periphery of the unvulcanized rubber molded body, and the unvulcanized rubber molded body is heated while applying a tightening force by the fiber woven fabric and / or fiber twist cord. Then, in the method for producing a rubber product by vulcanizing the unvulcanized rubber, the fiber fabric and / or the twist cord of the fiber contains polyketone fiber. 2. The method for producing a rubber product according to claim 1, wherein the polyketone fiber is a polyketone fiber represented by the following general formula (I).

(In the formula (I), R is a linking group derived from an ethylenically unsaturated compound, and each repeating unit may be the same or different.)   The method for producing a rubber product according to claim 2, wherein in the general formula (I), 80 mol% or more of R is a connecting group derived from ethylene.   4. The rubber according to claim 2, wherein the polymerization degree of the polyketone is a polymerization degree in which the solution viscosity measured in m-cresol at 60 ° C. is in the range of 1.0 to 10.0 dL / g. Product manufacturing method.   In a wrapping wrapping body for lapping vulcanization comprising a molded body of unvulcanized rubber and a fiber fabric and / or a fiber twisted cord wound around the outer periphery of the molded body of unvulcanized rubber, the fiber fabric and / or A wound body for lapping vulcanization, wherein the twisted cord of the fiber contains polyketone fiber.   A rubber product obtained by heating the wrapped body for wrapping vulcanization according to claim 5 to vulcanize unvulcanized rubber, and then removing the fiber woven fabric and / or the twisted cord of the fiber. .   A lapping cloth for wrapping an unvulcanized rubber molded body around the outer periphery of the unvulcanized rubber molded body, comprising a polyketone fiber woven fabric for wrapping vulcanization Tightening cloth.

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