JP3984111B2 - Method of joining fluororubber fabric, method of manufacturing fluororubber fabric tank seal, and fluororubber fabric tank seal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for joining fluororubber fabrics excellent in strength and solvent resistance, and a fluororubber fabric cloth excellent in strength and solvent resistance by sequentially joining the ends of the fluororubber fabric obtained by this method. The present invention relates to a method for producing a tank seal and a fluororubber-coated fabric tank seal excellent in solvent resistance obtained by this method.
[0002]
[Prior art]
For oil-based rubber fabrics with high aromatic content, general oil-resistant rubber fabrics such as NBR (acrylonitrile-butadiene rubber) fabrics are insufficient in terms of oil resistance, and fluororubber fabrics are used. ing. In general, the joining method of the fluororubber fabric is such that both ends of a pair of fluororubber fabrics are put together, and an unvulcanized unvulcanized fluororubber sheet is sandwiched between them, and press vulcanization is performed at 160 ° C. as primary vulcanization. The vulcanization is carried out for about 30 minutes, followed by secondary vulcanization by heating in a heating chamber at about 200 ° C. for about 10 hours to increase the strength. However, for example, in the case of the soft seal (envelope) used for the floating roof type tank seal shown in FIG. 2, the length in the circumferential direction of the floating roof is about 50 to 200 m and the width is about 1 m to 1.8 m. It is necessary to perform secondary vulcanization of a long fluororubber fabric soft seal (envelope) in a heating chamber that requires 10 hours of vulcanization time. It is practically impossible from a cost perspective.
[0003]
[Problems to be solved by the invention]
The present invention relates to a method for joining a fluororubber fabric having excellent solvent resistance and sufficient strength without using a secondary vulcanization process in joining the fluororubber fabric, a tank seal using the method, and It is an object of the present invention to provide a method for manufacturing the tank seal.
[0004]
[Means for Solving the Problems]
The present inventor polymerizes the fluororubber stretched cloth terminal and fixes it tightly by sewing, and by laminating an unvulcanized fluororubber sheet on this fixing part and press vulcanizing this laminated part. It has been found that strength and solvent resistance equal to or higher than those of secondary vulcanization can be realized without performing secondary vulcanization, and the present invention has been completed based on this finding.
That is, the present invention
(1) In the method of joining the end portions of the fluororubber fabric, the unvulcanized fluororubber sheet is polymerized by sandwiching it between both ends of the fluororubber fabric to form a three-layer structure, and the three-layer structure portion is sewn. A fluororubber fabric bonding method comprising: laminating an unvulcanized fluororubber sheet on both outer surfaces of the fixed part, and then press vulcanizing the laminated part.
(2) A plurality of ends of the long cylindrical body, which are produced by joining the end portions of the fluororubber fabric in order to produce a long joint fabric, and aligning both side edges of the long fabric. In a method for manufacturing a tank seal in which an elastic foam is filled inside a ring-shaped cylindrical body formed by connecting parts to each other, when the ends of the plurality of fluororubber fabrics are sequentially joined, a pair of Both ends of the fluororubber fabric are polymerized by sandwiching an unvulcanized fluororubber sheet between both ends, and the three-layer structure is fixed by sewing. A method for producing a tank seal, characterized by laminating unvulcanized fluororubber sheets and press vulcanizing the laminated portion, and
(3) A ring-shaped cylindrical shape formed by connecting both ends of a long cylindrical body fixed together by aligning both side edges of a plurality of long bonded fabrics obtained by sequentially joining the ends of fluororubber fabrics In the tank seal formed by filling the inside of the body with an elastic foam, the joint portion obtained by sequentially joining the end portions of the plurality of fluororubber fabrics is connected to both ends of the pair of fluororubber fabrics by unvulcanized fluorine. A rubber sheet is sandwiched between both end portions to form a three-layer structure, and the three-layer structure portion is fixed by sewing, and an unvulcanized fluoro rubber sheet is provided on both outer surfaces of the fixed portion. A tank seal formed by press vulcanizing the laminated part,
Is to provide.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The fluororubber fabric used in the present invention is obtained by coating and vulcanizing a fluororubber on both sides of a fiber cloth. If the fluororubber used is an elastic material containing fluorine and is suitable for coating, It can be used without any particular restrictions. For example, polytetrafluoroethylene, polychlorotrifluoroethylene, polytetrafluoroethylene fluoropropylene copolymer, polyvinylidene fluoride, polyvinyl fluoride, and the like can be used. High-aroma oil-resistant fluororubber and high-temperature heat-resistant fluororubber can be particularly preferably used.
The unvulcanized fluororubber sheet used in the present invention is the above-mentioned fluororubber sheet, and the fluororubber is not particularly limited, but the same quality as the fluororubber used for the rubberized cloth is desirable in terms of adhesion. . An unvulcanized fluoro rubber sheet having a thickness of 0.5 to 3.0 mm, preferably 1.0 to 2.0 mm can be used. The size of the unvulcanized fluoro rubber sheet can be selected according to the size of the joint.
In the method of joining the end portions of the fluororubber fabric of the present invention, when an unvulcanized fluororubber sheet is sandwiched and polymerized between both end portions to form a three-layer structure and the three-layer structure portion is sewn, In addition, twisting can be prevented and excellent bonding strength and solvent resistance can be achieved. The sewing of the present invention can be performed by sewing and fixing the joint portions in two dimensions, that is, in two or more rows or in a curved shape such as a vertical and horizontal direction or a spiral shape. Only one row of sewing is insufficient in fixing strength.
The thickness of the sewing thread may be # 0 to # 20, preferably # 0 to # 5 (the sewing thread count). A sewing pitch of 2 to 10 mm, preferably 3 to 8 mm can be used. The sewing row spacing can be 5 to 20 mm, preferably 8 to 15 mm.
FIG. 1 is a cross-sectional view of the joint portion of the present invention. The unvulcanized fluororubber sheet 3 is sandwiched between the fluororubber fabric end 1 and the fluororubber fabric end 2 on both sides, and is sewn firmly with the sewing thread 5, thereby having a close affinity, There is an effect of preventing the penetration of the solvent transmitted between the fluororubber-coated cloth end portions 1 and 2 on both sides. Further, after laminating the unvulcanized fluoro rubber sheet 4 on both outer surfaces of the sewing fixing portion, the laminated portion is press vulcanized to firmly adhere and protect the sewing thread penetrating portion and transmit the sewing thread penetrating portion. It has the effect of preventing the solvent from entering.
[0006]
The sewing thread material used for the sewing of the present invention can be used without particular limitation as long as it can realize a sufficient bond strength. For example, cotton yarn, hemp yarn, wool, silk yarn from natural materials, regenerated fiber, semi-synthetic fiber, viscose rayon, copper anthracite regenerated fiber, synthetic fiber, polyamide (nylon), polyester, polyacrylonitrile, acetate Triacetate, polyimide, polyurethane, fluorinated resin fiber, and the like can be used.
The elastic foam filling the inside of the tank seal ring-shaped cylindrical body of the present invention is such that the floating roof tank seal adheres to the inner wall of the tank, prevents evaporation of the internal liquid, and floats when the liquid level moves up and down. Any material can be used as long as the tank seal gives an appropriate elastic force to smoothly follow the inner surface of the tank. For example, polyurethane rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene can be used as the foam synthetic rubber material. -Styrene rubber (ABS), acrylonitrile-butadiene rubber (NBR), butyl rubber, chloroprene rubber, fluoride rubber, silicon rubber, thiocol rubber, acrylic rubber, isoprene rubber, polybutadiene rubber, ethylene-propylene rubber, polyether type Cork and sponges as elastic foams made from natural materials such as rubber Cotton fibers, can be used foamed natural rubber, a.
The size of the elastic foam filling the inside of the tank seal ring-shaped cylindrical body of the present invention is determined by the size of the gap between the tank inner wall to be equipped and the floating roof body. With the repulsive force of the filled elastic foam, the gap between the tank inner wall and the floating roof body can be reliably sealed, and smooth follow-up action can be performed for the vertical movement of the floating roof. Choose as possible. In order to achieve this function, polyurethane elastic foam is particularly suitable. A block-like polyurethane elastic foam that has been injection-molded into a predetermined shape may be loaded inside the tank seal ring-shaped cylindrical body, and an elastic foam polyurethane raw material liquid is injected into the tank seal ring-shaped cylindrical body, The foam may be filled in a predetermined shape.
[0007]
【The invention's effect】
According to the joining method of the present invention, the joining strength can be maintained by sewing, and the sealing performance of the sewn portion can be maintained with fluoro rubber. As a result, the fluororubber cloth used for tank seals can be joined in any size without using a heating chamber, and without any secondary vulcanization, a fluororubber cloth covering material that can sufficiently withstand the use can be manufactured. In particular, it is possible to provide a long soft seal material coated with a fluororubber fabric suitable for a high oil-resistant floating roof tank for storing oils with a high aromatic content (60% or more).
In addition, the floating roof type tank using the sealing material filled with elastic foam inside the covering material obtained by the present invention can be surely sealed by the repulsive force of the foam, and is smooth against the vertical movement of the floating roof. Follow-up operation is possible.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a joint using the joining method of the present invention.
FIG. 2 is an explanatory view showing a use state of a tank seal manufactured by using the joining method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fluoro-rubber cloth end part 2 Fluoro-rubber cloth end part 3 Unvulcanized fluoro rubber sheet 4 Unvulcanized fluoro rubber sheet 5 Sewing thread

Claims (3)

In the method of joining the end portions of the fluororubber fabric, the unvulcanized fluororubber sheet is sandwiched between both ends of the fluororubber fabric to form a three-layer structure, and the three-layer structure portion is fixed by sewing. Then, after laminating an unvulcanized fluororubber sheet on both outer surfaces of the fixed part, the laminated part is press vulcanized, and the fluororubber fabric bonding method is characterized. A plurality of ends of the fluororubber fabric are joined together in order to produce a long joint fabric, and both ends of the long cylindrical body fixed with the side edges of the long joint fabric are fixed together. In a method for manufacturing a tank seal in which an elastic foam is filled inside a ring-shaped cylindrical body formed by joining together, a pair of fluororubber pulling members are used when sequentially joining the ends of the plurality of fluororubber pulling cloths. Both ends of the cloth are polymerized by sandwiching an unvulcanized fluoro rubber sheet between the ends, and the three-layer structure is fixed by sewing, and then the unexposed portions are respectively applied to both outer surfaces of the fixing portion. A method for producing a tank seal, comprising laminating a fluorinated rubber sheet and then press vulcanizing the laminated portion. The inside of a ring-shaped tubular body formed by connecting both ends of a long tubular body, which are fixed together by aligning both side edges of a plurality of long-sized joined cloths that are joined together in sequence, the ends of fluororubber fabrics In addition, in the tank seal formed by filling the elastic foam, the joint portions obtained by sequentially joining the end portions of the plurality of fluororubber fabrics are connected to the both ends of the pair of fluororubber fabrics by using an unvulcanized fluororubber sheet. A three-layer structure is formed by sandwiching between both end portions, and the three-layer structure portion is fixed by sewing, and is a laminate in which uncured fluororubber sheets are laminated on both outer surfaces of the fixed portion, respectively. A tank seal formed by press vulcanizing the part.

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