JPH0136600Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a waterproof fabric exhibiting significantly improved tear strength.

[Conventional technology]

Conventionally, for open pile sheets, freight car seats, vehicle tops, etc., canvas made of spun yarns such as cotton, hemp, and polyvinyl acetal fibers are treated with paraffin or coated with synthetic resin on one or both sides. Waterproof laminated fabrics that retain their waterproof function have been used. However, this material has a large weight per unit area, relatively high water absorption, and relatively low strength per unit weight, resulting in poor durability. Since a spinning process is required, the cost of the yarn is high, and therefore the product is also expensive.

On the other hand, in recent years, there has been a demand for high-strength, lightweight, and low-cost canvas, and filament yarns of various synthetic fibers with high single-filament strength have come to be used. This type of filament yarn is a continuous yarn, so it has high efficiency in utilizing the strength of single fibers.
Therefore, the tensile strength of the knitted canvas is high, and the amount of yarn used can be reduced, making it possible to reduce the weight of the product. Furthermore, since filament yarns do not require a spinning process, they can be produced at a lower cost, making it possible to reduce the cost of waterproof fabrics, and have the various advantages mentioned above.

However, even waterproof fabrics manufactured using base fabrics made of these synthetic fiber filament yarns are not completely free from drawbacks, and if the base fabric has a high density or If the degree of freedom of fiber movement is significantly reduced by resin processing, the tear strength will be relatively low even if the tensile strength is excellent. For example, in the case of waterproof fabric for truck tops, which is obtained by waterproofing a base fabric woven using regular polyester filament yarn, if a small hook crack occurs in the top, an L-shaped tear will occur from that part. However, within a short period of time, it becomes a major rift.

As a countermeasure to the above-mentioned drawbacks, attempts have been made to weave thick threads into the base fabric to increase the tear strength of the base fabric. In this case, it is thought that thick threads will strongly resist tearing, but in reality, even if thick threads are woven, there will only be more fibers in that area, which will prevent tearing. Under accelerated conditions, tearing, including thick threads, progresses in an impactful manner, making it difficult to expect much effect in preventing tearing. In addition, since the woven thick yarns rise up on the surface of the fabric, when a waterproof coating is formed on them, the top of the coating breaks off in this area, which reduces the waterproofing effect.

In order to prevent this drawback, it is necessary to make the resin layer sufficiently thick and to make its surface smooth.
This not only increases the number of resin layers used, increasing manufacturing costs, but also causes the disadvantage that the resulting product is excessively heavy and thick.

[Problem that the idea is trying to solve]

An object of the present invention is to provide a waterproof fabric with excellent tear strength.

[Means and effects for solving the problem] The waterproof fabric of the present invention has a base made of a fabric made of high-strength yarns made of para-aramid aromatic polyamide filaments and different organic fiber yarns. It is characterized by comprising a cloth and a waterproof coating bonded to at least one surface of the base cloth.

The base fabric used in the waterproof fabric of the present invention may be either a filament yarn fabric or, in some cases, a filament yarn/spun yarn mixed fabric, and there are no particular limitations on its structure or fabric weight. In general, woven fabrics such as plain weave, twill weave, satin weave, and leno weave are preferred, and the void ratio is 20%.
The effects of the present invention are particularly exhibited in the following cases where the fabric has a high density.

The base fabric used in the present invention is a woven fabric composed of high-strength yarns made of aromatic polyamide filaments and different organic fiber yarns. The aromatic polyamide filament high-strength yarn used in the present invention is a Kevlar type, that is, a para-aramid type, which has a high breaking strength of 15 g/d or more, and has a breaking strength higher than that of a different type of yarn. have. but,
The elongation at break of a different type of yarn is higher than that of a high-strength yarn, and is generally 1.1 times or more the elongation at break of a high-strength yarn. The waterproof fabric obtained using the above-mentioned base fabric can exhibit extremely high tear strength due to the synergistic effect of the high strength of the high-strength yarn and the high elongation of the different organic fiber yarn.

In addition, the Kevlar type, that is, the para-aramid type aromatic polyamide filament, is the meta-aramid type (relatively low strength (5 to 6 g/d) and high elongation (20
~45%))).

The proportion of high-strength yarn in the base fabric is preferably in the range of 5 to 95% by weight, more preferably in the range of 15 to 85% by weight.

The high-strength yarns used in the base fabric may be either twisted yarns or untwisted yarns, and are preferably regularly mixed and arranged with different types of yarns according to a predetermined structure. , or may be aligned with different organic fiber yarns, may be twisted together, or may be entwined.

There are no particular limitations on the different organic fiber yarns, but preferably polyester fiber yarns, nylon fiber yarns, polyvinyl acetal fiber yarns, etc., which have a breaking elongation of 1.1 times or more the breaking elongation of high-strength yarns. You can choose from.

The waterproof coating formed on one or both sides of the base fabric is made of natural rubber, synthetic rubber such as neoprene, Hypalon, etc., or synthetic resin such as polyvinyl chloride, ethylene-vinyl acetate copolymer, polyacrylic resin, It is made of one or more selected from polyurethane resins, etc.

The waterproof fabric of the present invention has a structure as shown in FIG. 1, for example. In FIG. 1, waterproof coatings 2a and 2b are formed on both sides of a base fabric 1. The waterproof coating may be formed on only one side of the base fabric.

Formation of the above-mentioned waterproof coating is performed by a conventional method. For example, a solution or emulsion (latex) of the above-mentioned rubber or resin may be applied to the desired surface of the base fabric (coating, topping), or the base fabric may be impregnated (dipping), or the above-mentioned rubber,
Alternatively, a resin film may be laminated onto the desired surface of the base fabric for adhesion.

The waterproof coating may contain pigments, fillers, and other adhesion agents as long as they do not adversely affect its waterproof properties.

The present invention will be further explained below with reference to Examples.

〔Example〕

Every sixth polyester filament yarn (breaking strength: 8 g/d, breaking elongation: 12%, total denier: 500) for both warp and weft, aromatic polyamide filament yarn (breaking strength: 20 g/d, breaking elongation: 4) %, total denier: 500, product name: Kevlar 29, manufactured by Dupont) were woven into plain weave fabrics with warp and warp densities of 28 threads/25.4 mm each.

A waterproofing agent consisting of a mixture of 90% by weight polyvinyl chloride and 10% by weight ethylene/vinyl acetate copolymer is applied to both sides of the base fabric, and the average thickness is
A 0.3mm waterproof film was formed.

The tear strength of the obtained waterproof fabric was 12.3 kg. For comparison, similar waterproof fabrics were made using only polyester filament yarns and only aromatic polyamide filament yarns. The tear strength of the obtained waterproof fabrics is 4.5, respectively.
Kg and 8.7 Kg, which was significantly inferior to the tear strength of the waterproof fabric of the present invention.

[Effect of idea]

By arranging high-strength para-aramid aromatic polyamide filament yarns and high-elongation heterogeneous yarns in the base fabric, the waterproof fabric of the present invention can exhibit unexpectedly excellent tear strength. .

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view showing the structure of the waterproof fabric of the present invention. 1...Base fabric, 2a, 2b...Waterproof coating.

Claims (1)

[Claims for Utility Model Registration] 1. A base fabric made of a woven fabric composed of a high-strength yarn made of para-aramid type aromatic polyamide filament and a different type of organic fiber yarn, and at least one of the base fabrics. and a waterproof coating formed from natural rubber, synthetic rubber, or synthetic resin, and the elongation of the dissimilar organic fiber yarn is greater than the elongation of the high-strength yarn. Improved waterproof fabric characterized by high tear strength. 2 Utility model registration claim No. 1 in which the dissimilar organic fiber yarn is a polyester filament yarn
Waterproof fabric as described in section.