JPH046908Y2 - - Google Patents

Description

[Detailed explanation of the idea]

<Technical Field of the Invention> The present invention relates to a polyvinyl alcohol fiber-based waterproof fabric that is soft and lightweight, yet has high strength and high elastic modulus. <Conventional technology> Conventionally, waterproof fabrics whose constituent fibers are synthetic fibers have been widely used in large tents, vehicle hoods, marine seats, tent warehouses, etc. Polyester has been used as the constituent fibers of these waterproof fabrics. ,Nylon,
Filaments and spun yarns such as vinylon are used. Waterproof fabrics used for each of these applications are required to have high tensile strength and high tearing strength in addition to waterproof performance, and in addition, lightness is strongly desired as a recent market need. However, conventional synthetic fibers, even high-strength multifilament for industrial materials, have low tensile strength, and in order to obtain the strength required for designing waterproof fabrics, it is necessary to increase the amount of thread in the base cloth of waterproof fabrics. Lightness cannot be achieved. In order to obtain sufficient lightness, it is necessary to reduce the amount of thread in the base cloth, but in this case, the disadvantage is that the strength necessary for the design of the waterproof cloth cannot be obtained. In addition, the tear strength of waterproof fabric is highly dependent on the tensile strength of the fibers used for the base cloth, and in order to obtain high tear strength, it is necessary to use high-strength fibers as the constituent fibers of the base cloth. The conventional ones did not have sufficient tear strength. Furthermore, in applications where the waterproof fabric is used as a structural material for buildings such as large tents, the higher the elastic modulus of the waterproof fabric, the better. In these cases, conventional synthetic fibers were not used as the constituent fibers of waterproof fabrics, but special fibers such as glass fibers or aramid fibers (especially polyparaphenylene terephthalamide fibers) were used. Conventional polyvinyl alcohol (hereinafter abbreviated as PVA) fibers are usually produced using a PVA aqueous solution as the spinning stock solution.
Discharged into a coagulation bath through a spinneret and coagulated,
After the obtained coagulated thread is washed with water, stretched, and dried, it is manufactured through a process of performing a water-insoluble treatment such as acetalization. On the other hand, obtained in such a manufacturing method
Many proposals have been made to improve the mechanical strength of PVA fibers.
Examples include JP-A No. 48-9209 and (b) JP-A-56-128309. Furthermore, recently, a proposal for obtaining fibers with high strength and high modulus of elasticity by applying a gel spinning method to PVA polymers has been described in (c) Japanese Patent Application Laid-Open No. 130314/1983. However, although the PVA fibers obtained in (a) and (b) certainly have improved mechanical properties compared to conventional PVA fibers, the aramid fibers (especially polyparaphenylene terephthalamide fibers)
It did not exhibit a high degree of mechanical properties comparable to that of . In addition, a detailed study of the fibers and manufacturing method described in (c) reveals that the PVA polymer used is obtained by a very special polymerization method, making it difficult to obtain commercially. Also,
low solubility of PVA polymers in solvents;
There are problems such as unavoidable reduction in productivity due to lack of uniformity of the spinning dope. Furthermore, when the present inventors conducted a follow-up test on the invention described in (c), they found that during the process of desolventizing and drying the extruded, cooled, and gelled yarn from a nozzle having multiple holes, there was a significant gap between the single yarns. It was found that sticking occurred and it was not suitable for producing multifilament yarns. The sticking between single yarns that occurs in this way reduces the strength of the yarn itself, and on the other hand, there are problems such as a lack of yarn flexibility and a decrease in strength utilization during twisting and fabric manufacturing processes. It was hot. Therefore, as mentioned above, conventional PVA fibers
The reality is that there are many inconveniences in achieving the required mechanical strength as a waterproof fabric, and furthermore, mass production on an industrial scale has become extremely difficult. <Problems to be Solved by the Invention> The purpose of the invention is to provide a waterproof fabric that is soft and light, yet has high strength, high tear strength, and high modulus of elasticity. <Means for solving the problems> The waterproof fabric according to the present invention is made of a polyvinyl polymer with a degree of polymerization of 1500 or more, and has a tensile strength of 15 g/
d or more, the initial elastic modulus is 250 g/d or more, the multifilament constituent single fiber fineness is 5 d or less, the total number of filaments is 20 or more, no long-period image is observed in small-angle X-ray scattering measurement, and It is made by waterproofing a fabric made of polyvinyl alcohol-based multifilament, which does not cause stickiness between single yarns, with thermoplastic resin or synthetic rubber. PVA, which is the constituent fiber of the waterproof fabric related to this invention
The PVA polymer constituting the multifilament yarn is not particularly limited as long as it has a degree of polymerization of 1,500 or more, preferably 2,500 or more and has fiber-forming properties, such as partially saponified PVA,
Fully saponified PVA and a small amount of vinyl monomer copolymerizable with vinyl alcohol were polymerized.
Examples include PVA copolymer. The method for turning such PVA polymer into threads is as follows:
There is a method in which a solution of the polymer is spun through a nozzle with multiple holes (20 or more holes) and solidified by dry-wet spinning or gel spinning, or solidified by cooling. The dry-wet spinning method is a spinning method in which a solution containing the polymer is once discharged into an inert atmosphere such as air, and then the discharged thread is formed into a thread in a coagulation bath or a cooling liquid. Here, the distance that the discharged yarn travels in the inert atmosphere (distance from the mouth surface to the coagulation bath surface) is not particularly limited, but is suitably 3 mm to 50 mm. As solvents for PVA-based polymers in the dry-wet spinning method, organic solvents such as dimethyl sulfoxide (DMSO), glycerin, ethylene glycol, diethylene triamine, ethylene diamine, and phenol, and inorganic solvents such as water, zinc chloride, rhodan soda, calcium chloride, and aluminum chloride are used. Examples include aqueous salt solutions and mixed solvents thereof, but DMSO, diethylenetriamine, and ethylenediamine are particularly preferred, and DMSO is more preferred. In addition, coagulants include alcohols such as methanol, ethanol, butanol, acetone,
benzene, toluene, etc., or a mixed solvent of one or more of these and DMSO, a saturated inorganic salt aqueous solution,
Examples include a caustic soda aqueous solution, but methanol, ethanol, and acetone are preferable. On the other hand, in the gel spinning method, as a solvent for the PVA-based polymer, a solvent is used that is heated and dissolved at a high temperature, turns into a gel when the resulting solution is cooled, and is nonvolatile under the spinning conditions. be done. The cooling liquid that gels the fibrous solution extruded from a multi-hole nozzle includes decalin, trichlorethylene, carbon tetrachloride, paraffin oil,
Kerosene etc. are used. Note that the distance between the multi-hole nozzle and the liquid surface of the cooling medium bath is the same as in the case of the wet-dry spinning method. The yarn coagulated by the dry-wet spinning method is subsequently subjected to solvent removal. On the other hand, the gelled thread cooled by the gel spinning method is subsequently subjected to solvent removal, and finally the solvent is replaced by the extractant used for solvent removal. The yarn thus obtained is sent to a drying process. During drying, the yarn is Turbulent gas is blown onto the yarn to spread out the individual filaments that make up the yarn, and the yarn is dried while being vibrated. The dry yarn thus obtained is subsequently hot drawn. The stretching temperature is lower than the melting point of the PVA polymer, and is preferably in the range of 160°C to 250°C. For stretching, the total stretching ratio throughout the entire process is as high as possible, for example, 85% or more of the stretching ratio that involves cutting the yarn, and when the stretched yarn is subjected to small-angle X-ray scattering measurement, a long-period image is observed. Stretch until it runs out. At this time, if the single filament fineness of the multifilament yarn exceeds 5d, it becomes difficult to obtain the multifilament yarn of the present invention with high physical properties. The thus obtained polyvinyl alcohol multifilament yarn of the present invention has a fineness of the constituent single yarns of 5 d or less, a total number of filaments of 20 or more, a tensile strength of 15 g/d, and an initial elastic modulus of 250.
g/d or more. Such polyvinyl alcohol-based multifilament yarns are insoluble in water (including boiling water) and have higher strength and higher initial elastic modulus than conventional PVA-based fibers. In addition, conventional polyester,
It has superior mechanical properties compared to industrial fibers such as nylon. The waterproof fabric of the present invention is produced by treating a fabric made of such PVA-based fibers with a thermoplastic resin or synthetic rubber. Fabrics include regular woven fabrics, tricots, etc. As the thermoplastic resin, polyvinyl chloride, polyurethane, polyvinyl acetate, polyacrylic ester, etc. are used. Further, as the synthetic rubber, polychloroprene rubber, nitrile rubber, chlorosulfonated polyethylene, etc. are used. Waterproofing methods using these thermoplastic resins or synthetic rubbers include a coating method in which the thermoplastic resin or synthetic rubber is coated in a fluid solution state and dried by heating, and a plastisol solution of the thermoplastic resin or synthetic rubber is coated with a fabric. Dipping method, in which the resin or synthetic rubber is gelled by dipping and heat treatment; topping method, in which a melt of thermoplastic resin or synthetic rubber is thermally fused to the surface of the fabric; or lamination of thermoplastic resin or synthetic rubber film. The method will be adopted. FIG. 1 shows a waterproof fabric made by knife-coating a thermoplastic resin or synthetic rubber 2 on a fabric 1 made of a polyvinyl alcohol multifilament yarn having high strength and high modulus of elasticity. <Effects of the invention> The waterproof fabric according to the invention has high strength and tear strength, a high initial elastic modulus, little dimensional change due to external force, and excellent weather resistance and fatigue resistance. Furthermore, due to the excellent adhesive properties unique to polyvinyl alcohol fibers, it is easy to bond thermoplastic resins or synthetic rubbers to fabrics during waterproofing. The waterproof fabric according to the present invention has such excellent properties and can be effectively used for large tents, vehicle hoods, boat seats, tent warehouses, etc. Hereinafter, the present invention will be specifically explained with reference to Examples. Examples 1 to 3, Comparative Examples 1 to 2 Completely saponified PVA with a degree of polymerization of 1500, 1900, and 3100 (saponification degree of 99.5% or more) was melted in DMSO to prepare a spinning stock solution, and these three spinning stock solutions were prepared. 10% by weight from a spinneret with a pore size of 0.06 mm and a number of holes of 100.
extruded into a methanol coagulation bath containing DMSO;
Wet-dry spinning. The distance between the spinneret surface and the coagulation bath liquid level was set to 7 mm. The obtained coagulated threads were each washed with methanol to remove DMSO, and then stretched four times in methanol, and dried while stirring and vibrating the threads with air turbulence. Next, the obtained dry yarns were each hot-stretched in a dry heat tube set at 235°C to 200 denier,
100 filament high strength, high initial modulus PVA
A multifilament yarn was produced. The properties of such fibers are shown in Table 1. On the other hand, for comparison, when drying a yarn that has gone through the coagulation and methanol drawing process without being vibrated by air turbulence, inter-filament adhesion occurs in the dried yarn, resulting in poor spreadability. It was significantly inferior. In addition, the drawing ratio is low in the hot drawing process, and the tensile strength is low.
It does not exceed 15 g/d, and long-period images appear even in small-angle X-ray scattering measurements.

[Table] Five types of fibers A to E shown in Table 1 above were combined to form a 600D multifilament yarn, which was twisted at 200T/M to obtain a raw yarn for weaving. Next, plain weaving was carried out at a weave density of 35 yarns/inch in the warp and 33 yarns/inch in the width to obtain a fabric. This fabric was coated with polyvinyl chloride paste and then baked to produce a waterproof fabric weighing approximately 340 g/m ² . The tensile strength, tear strength, and initial tensile modulus of this waterproof fabric were measured. The results are shown in Table 2.

[Table] As shown in Table 2, the waterproof fabric according to the present invention whose constituent fibers are polyvinyl alcohol multifilament yarns with high strength and high initial elastic modulus,
It can be seen that both tensile strength and tear strength are high, and the initial tensile modulus is high.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention. 1... Fabric made of multifilament yarn, 2... Thermoplastic resin or synthetic rubber, 3...
Waterproof cloth.

Claims (1)

[Scope of utility model registration request] It is made of a polyvinyl alcohol polymer with a degree of polymerization of 1500 or more, a tensile strength of 15 g/d or more, and an initial elastic modulus of 250 g/d or more, and no long-period image is observed in small-angle X-ray scattering measurements, making it virtually simple. A waterproof fabric comprising a thermoplastic resin or synthetic rubber layer provided on at least one side of a fabric made of multifilament yarn, which is free from inter-yarn sticking, has a fineness of constituent single yarns of 5d or less, and has a total number of filaments of 20 or more.