JPH01139807A - Synthetic fiber having excellent alkali and heat resistance and production thereof - Google Patents

Abstract

PURPOSE:To obtain a synthetic fiber, having excellent alkali and heat resistance at high temperatures and specific boiling-water shrinkage, dissolving or dispersing PVC and poly(ether)sulfone at a specific ratio in a solvent and forming the resultant solution or dispersion into a fiber by a wet spinning method. CONSTITUTION:85-30wt.% PVC (preferably 1000-1800 polymerization degree) and 15-70wt.% polysulfone and/or polyether sulfone are solved or dispersed in a solvent (preferably dimethylacetamide, etc.) and the resultant solution or dispersion is wet spun into a fiber, having <=25% boiling water shrinkage and suitable as a battery separator paper of alkaline storage batteries.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The invention relates to a synthetic fiber with excellent alkali resistance and a method for producing the same.

Conventional technology> Conventionally, polyvinyl chloride fibers have excellent properties such as chemical resistance and self-extinguishing properties, and are widely used in the clothing and industrial fields, such as blankets, fishing nets, rosettes, and underwear. There was a gap in the quality of the product, and improvements were desired.

As an improvement of such heat resistance, a method of improving the heat resistance of polyvinyl chloride-based MS by mixing post-chlorinated polyvinyl chloride with polyvinyl chloride (% 1986-65422)
No. 2) has been proposed. However, post-chlorinated polyvinyl chloride has inferior alkali resistance at high temperatures compared to polyvinyl chloride, making it unsuitable for industrial material applications that require alkali resistance at high temperatures, such as battery separators. A method to improve sex was desired.

<Problems to be solved by the invention> The purpose of the present invention is to solve the disadvantages of polyvinyl chloride fibers,
In other words, the heat resistance is improved without impairing the excellent alkali resistance inherent to polyvinyl chloride fibers, and it can be effectively used as a fiber material for paper, nonwoven fabrics, and knitted fabrics in the clothing and industrial materials fields. An object of the present invention is to provide a novel synthetic fiber having alkali resistance and heat resistance, and a method for producing the same.

Means for solving the problems〉 The non-invention is tl) The polymer composition in the fiber is polyvinyl chloride 85
~30% by weight and 70% by weight to polysulfone and/or polyethersulfone 15, with boiling water shrinkage of 25%
A synthetic fiber with excellent alkali resistance and heat resistance, characterized by the following properties: and (2) 50% by weight of polyvinyl chloride 85S and polysulfone and/or polyethersulfone 15-50% by weight
This synthetic fiber has excellent alkali resistance and heat resistance, and is characterized by dissolving and dispersing the composition in a solvent and forming the fiber by a wet spinning method.

The polymer composition of the fibers of the present invention is polyvinyl chloride (PVG).
) 50% by weight to 85 and 70% by weight to polysulfone and/or polyethersulfone 15.

If the PVC content exceeds 85% by weight, the heat resistance of the fibers will be insufficient and the shrinkage rate will exceed 25%. Also pvc is 3
If it is less than 0% by weight, it is difficult to produce fibers with practically sufficient physical properties because the stretchability of the undrawn system obtained by the wet spinning method is insufficient.

The degree of polymerization of PVC used in the invention is preferably 800.
~2500, more preferably 1000-180
S at 0. If the pvco polymerization degree is less than 800, the strength of the obtained fiber is poor and it is difficult to say that it is sufficient for practical use. Furthermore, if the degree of polymerization of PVC exceeds 2500 t-, the spinning dope tends to gel in a short period of time. Here, the degree of polymerization of pvc is JZSK
-672).

The polysulfone and polyethersulfone used in the invention have the following chemical structure (tl t ([l), and the degree of polymerization is not particularly defined, and is usually made of molding material such as glasstic. The range used for this is sufficient.

polysulfone; Oh.

Polyethersulfone; The polymer composition of the fibers of the present invention includes, but is not limited to, PVC and polysulfone and/or polyethersulfone mixed or dispersed in a solvent. It is possible to add any polymer that can be used to form fibers, and the amount added is preferably less than 5% by weight.

In addition, it is preferable to add a dibutyltin malate-based polymer composition, which is usually used as a stabilizer for PVO, and it is preferable to add 0.5% by weight or more to the spinning dope in the wet spinning method. provides long-term stability.

A specific guideline for alkali resistance at high temperatures in the present invention is that the fiber loss after being immersed in a 50% KO3 aqueous solution and left at normal pressure boiling for 1 hour is 20% by weight or less. The same method was used to evaluate the prophylaxis of shiboripropylene, and it corresponds to the value.

The inventive fiber is produced by a wet spinning process. As the solvent for wet spinning, any single solvent or mixed solvent can be used as long as it has the ability to dissolve and disperse PVC, polysulfone, and/or polyethersulfone, and dimethyl is preferably used as the solvent. Dimethylacetamide, dimethylformamide, which includes acetamide, dimethylformamide, dimethylsulfoxide, acetone, etc., is more preferably used as a solvent. A stock solution for spinning is prepared by mixing and dispersing PVC, polysulfone, and/or polyethersulfone in these solvents.The spinning stock solution can be prepared by mixing all of the polymers in advance and dissolving them in a solvent, or by individually mixing the above-mentioned polymers. obtained by mixing a polymer solution dissolved in The viscosity of the spinning stock solution at 50°C is preferably 10,052,000 voids, more preferably 150 to 1,000 voids, and the solid content concentration of the stock solution is adjusted to these values.
The solid content concentration is preferably 50% by weight or less in order to prevent gelation.

The obtained spinning dope is discharged from a spinneret into a coagulating liquid and shaped into fibers. The size of the spinneret is appropriately selected depending on the target thickness of the fiber. As a coagulant for the coagulation liquid, water, alcohol, etc., which are non-solvents for the polymer, are used, and water is preferably used industrially. The ratio of coagulant and solvent in the coagulation liquid is #solid agent 20S60''ILt%, solvent 80-4
A composition of 0% to 1% by weight is desirable. When the coagulant ratio is less than 20wt2, the fibers discharged into the coagulation liquid will adhere. On the other hand, if the proportion of the coagulant exceeds 60% by weight, the coagulated fibers will not adhere, but a large amount of voids will be generated in the coagulated fibers, impairing the stretchability necessary to impart appropriate strength and elongation to the fibers.

The obtained coagulated thread has a temperature of 80°C or lower, preferably 50 to 70°C.
Washed in warm water at °C and stretched if necessary. After being washed in warm water or washed and stretched, the fibers are further washed in water or stretched as necessary to impart appropriate physical properties as a fiber.

<Effects of the Invention> As described above, the #l fiber of the present invention has excellent alkali resistance at high temperatures and also has excellent heat resistance, so it can be used in the field of industrial materials that require alkali resistance, such as paper for battery separators of alkaline storage batteries. It is effectively used as a raw material for non-woven fabrics, knitted fabrics, clothing, and interior applications.

<Example> Hereinafter, the present invention will be explained by way of examples.

To Example 1 4 Using dimethylacetamide as a solvent, the degree of polymerization was 11.
A spinning stock solution with different mixing ratios of PVA 00 and polysulfone was prepared, and 30% by weight of water and dimethyl 7adamide 7a were prepared.
road iijkg6, into the coagulation liquid at a temperature of 30℃, o, oss
The coagulated thread discharged through a mφ nozzle and taken out was washed in hot water at 70°C, stretched 4 times, and further washed in water, applied with an oil agent, and dried to produce the fibers shown in Table 1. Obtained.

Alkali resistance is determined by immersion in a KOH 30% aqueous solution for 12 hours.
Fiber loss was measured after being left at 0°C for 1 hr.

As is clear from Table 1, the physical properties of the fibers spun into PVC 85 with a composition of 50% by weight and 70% by weight of polysulfone 15S had a water production shrinkage rate of 253 or less and excellent alkali resistance at high temperatures.

Examples 5-6 The weight ratio of PVC with a polymerization degree of 1100 and polysulfone is 7
The composition of =3 was bound in dimethylacetamide, and a spinning stock solution having a solid content of 28 weight ftX of dibutyltin malate-based polymer was prepared. These spinning stock solutions were allowed to stand at -70°C for one week. As a result, as shown in Table 2, in order to keep the spinning dope stable, dibutyltin malate polymer must be added at 0.00%.
It can be seen that it is preferable to add 5% bop or more.

Table 2 Examples 7 to B PVA having a degree of polymerization of 1100 and folysulfone were dissolved in dimethylacetamide at a composition ratio of 70750 to obtain a spinning material g. This spinning stock solution was trap-spun in a mixed coagulation solution of dimethylacetamide and water, and a spinning experiment was conducted in the same manner as in Example 1, with the mixing ratio of the coagulation solution changed as shown in Table 3.

Table 5 From the results in Table 5, when the proportion of water exceeds 60% by weight,
Since yarn breakage and eyelids occur in the spinneret, spinning becomes impossible, and if the water content is less than 20% by weight, the fibers will undergo welding in the coagulation bath. Water is 20S601t%,
Within the range of composition ratio of 80% dimethylacetamide to 40% t5A, fibers with practically sufficient physical properties can be produced.

Examples 9 to 12 PVC polymers with different degrees of polymerization and polysulfone were each dissolved in dimethylacetamide at a composition ratio of 70,750 to obtain a spinning stock solution.

From the spinneret containing this stock solution t-o, os φ, the fiber was spun into a coagulation solution containing 50% by weight of water and 0% by weight of dimethyl acedobate at a temperature of 50°C, and the fiber was drawn in the same manner as in Example 1. Washing was performed to obtain fibers with d/f shown in Table 4.

As is clear from Table 5, in order to maintain the physical properties of the fibers, especially the strength, it is necessary to appropriately select the degree of polymerization of PVA. In addition, although PVC with a polymerization degree of 2900 was used, it gelled within several hours, making it impossible to spin it using a spinning nozzle.

Example 15 When the undrawn yarn, which was spun in the same manner as in Example 1 and taken from the coagulation solution, was washed and stretched in water, the fibers were fused and became tape-shaped. Nine.

On the other hand, when the undrawn yarn f taken from the coagulation liquid was washed in warm water at 0° C. and stretched 4 times, and then washed in boiling water, no fusion of the fibers was observed.

Comparative Example PVC with a polymerization degree of 1100 and post-chlorinated PVC with a polymerization degree of 1100 and a chlorine content of 67% by weight were dissolved in dimethylacetamide Km at a weight ratio of 70150 to obtain a spinning stock solution. This spinning solution was wet-spun in the same manner as in Example 1, and the fineness was 1.5 denier, the strength was 1.717a, the elongation was 18%, and the water shrinkage rate was 2.
0% fiber was obtained. When the alkali resistance loss of this fiber was measured by the method described in the text, it was 5.4% by weight, which did not have sufficient alkali resistance performance.

Patent applicant: Mitsubishi Rayon Co., Ltd.

Claims (5)

[Claims] (1) The polymer composition in the fiber is polyvinyl chloride 85-3
0% by weight and 15-70% by weight of polysulfone and/or polyethersulfone, and has a boiling water shrinkage rate of 25% or less, and has excellent alkali resistance and heat resistance. (2) Alkali-resistant and heat-resistant, characterized by dissolving and dispersing a composition of 85 to 30% by weight of polyvinyl chloride and 15 to 70% by weight of polysulfone and/or polyethersulfone in a solvent and forming the fiber by a wet spinning method. A method for producing synthetic fibers with excellent properties. (3) The method according to claim 2, which uses a polymer having a polyvinyl chloride polymerization degree of 800 to 2,500. (4) The method according to claim 2, wherein at least one solvent selected from the group of dimethylacetamide, dimethylformamide, dimethylsulfoxide, and acetone is used as the solvent. (5) The method according to claim 2, wherein the coagulating liquid is a mixture of a solvent and a coagulant, and the proportion of the coagulant is 20 to 60% by weight.