JP2002339167A - Polyurethane-based elastic fiber and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an environmentally friendly polyurethane-based elastic fiber. SOLUTION: This polyurethane-based elastic fiber is characterized by containing a titanium oxide-based pigment substantially free from arsenic.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyurethane-based elastic fiber and a method for producing the same.

More particularly, the present invention relates to an environmentally friendly polyurethane-based elastic fiber and a method for producing the same.

[0003]

2. Description of the Related Art Conventionally, titanium oxide pigments have been used as matting agents in polyurethane elastic fibers.

[0004] The raw materials of such titanium oxide pigments contain very small amounts of arsenic at concentrations far below environmental standards, and titanium oxide pigments as products contain very small amounts of arsenic.

[0005] Polyurethane elastic fibers using titanium oxide pigments may also use very small amounts of titanium oxide pigments, and polyurethane elastic fibers also contain very small amounts of arsenic.

[0006] In recent years, environmental problems have been highlighted, and at present, arsenic is accumulated in industrial waste facilities by continuing its use without affecting the environment, thereby affecting the environment. It is a concern.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an environment-friendly polyurethane elastic fiber and a method for producing the same.

[0008]

The polyurethane elastic fiber of the present invention employs the following means to solve the above-mentioned problems.

That is, a polyurethane-based elastic fiber characterized by containing a titanium oxide-based pigment substantially containing no arsenic.

The method for producing a polyurethane-based elastic fiber of the present invention employs the following means in order to solve the above problems.

That is, there is provided a method for producing a polyurethane-based elastic fiber, which comprises using a titanium oxide-based pigment substantially containing no arsenic.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The polyurethane elastic fiber of the present invention contains a titanium oxide pigment.

The titanium oxide pigments used in the present invention include titanium dioxide pigments, diluted titanium oxide pigments (composite titanium oxide pigments), and titanium oxide solid solution pigments (TiO.sub.2).
₂ -Sb ₂ O ₃ -NiO-based yellow pigment) and the like are preferable. Such a titanium oxide pigment is produced by a chlorine method, a sulfuric acid method, or the like.

The titanium oxide pigment used in the present invention is substantially free of arsenic. "Substantially free of arsenic" means that the content of arsenic in the polyurethane elastic fiber is 1 ppm or less.

A sulfuric acid method and a chlorine method are employed as industrial methods for producing titanium oxide pigments.

In the sulfuric acid method, ilmenite ore or titanium slag is used as a raw material ore, and the raw material ore is reacted with sulfuric acid to convert Ti, Fe, etc. into water-soluble sulfates, and is extracted with water to obtain a main component of Ti, The ore reaction step for preparing a sulfate solution of Fe, the insoluble suspension mainly composed of SiO ₂ or the like is precipitated with a flocculant, and the solution for the purpose of removing the sulfate solution from the sulfate solution. Refining step, hydrolysis step for hydrolyzing titanyl sulfate in the solution to precipitate as insoluble white hydrous titanium oxide, removing coloring metals such as Fe, Cu, Mn, and Cr derived from raw material ores Thereby, the purity of titanium oxide is improved, the deterioration of whiteness due to coloring is suppressed, and H ₂ SO ₄
A washing step aimed at reducing the hardness of the calcined titanium oxide material obtained in the calcining step by reducing the content, calcining the washed hydrous titanium oxide at 900 ° C. or higher using a rotary kiln, Baking process for the purpose of evaporating, decomposing and desorbing water and sulfuric acid contained in and converting it to anhydrous titanium, and pulverization and the purpose of improving the dispersibility of the fired titanium oxide material It consists of a surface treatment step.

In the chlorine method, synthetic rutile obtained by treating rutile or ilmenite ore is used as a raw ore, and the raw ore is subjected to an exothermic reaction with chlorine gas under a reducing condition using a fluidized bed chlorination furnace. A chlorination step aimed at cooling and condensing the high temperature gas to prepare a crude titanium tetrachloride solution, and removing chlorides such as C, Si, and Sn from the crude titanium tetrachloride solution to achieve high purity. A rectification process aimed at refining titanium tetrachloride, by burning titanium tetrachloride with oxygen to determine the primary particle size and crystal form of titanium oxide, and to suppress the generation of coarse particles and the deterioration of whiteness. It comprises an intended oxidation step and a pulverization and surface treatment step for the purpose of improving the dispersibility and the like of the titanium oxide material obtained in the oxidation step.

In the present invention, in order to obtain a titanium oxide pigment substantially containing no arsenic, for example, in the case of the sulfuric acid method, it can be achieved by sufficiently washing the hydrous titanium oxide precipitated by hydrolysis. Further, the chlorine method can be achieved by sufficiently rectifying the crude titanium tetrachloride solution.

The polyurethane elastic fiber of the present invention is a fiber obtained by spinning a polyurethane spinning stock solution.

The polyurethane polymer in the present invention may be a polyurethane-urea copolymer, or a mixture or a copolymer of polyurethane and polyurethane-urea.

More specifically, the polyurethane polymer of the present invention comprises two types of segments: (a) a long-chain polyether, a soft segment which is a polyester segment, and (b) an organic isocyanate and a diamine chain extender. Or a hard segment that is a relatively short-chain segment derived by reaction with a diol chain extender.

Usually, such a polyurethane polymer may be obtained by a prepolymer method in which a prepolymer product obtained by capping a hydroxyl-terminated soft segment precursor with an organic diisocyanate is chain-extended with a diamine or a diol, or May be obtained by a one-shot method in which all the raw materials are put in the same bath and polymerized,
Also, it may be obtained by other methods.

A typical polyether soft segment is polytetramethylene ether glycol (hereinafter referred to as P
TMG), those derived from 3-methyl-1,5-pentanediol, tetrahydrofuran, 3-methyltetrahydrofuran, and the like, and copolymers thereof. Among them, a polyether derived from polytetramethylene ether glycol is preferred. Typical polyester soft segments include (a) ethylene glycol, polytetramethylene ether glycol, 2,2-dimethyl-1,3-propanediol, and (b) dibasic acids such as adipic acid and succinic acid. And the like.

The soft segment may be from typical polyethers and polyesters, or from polycarbonate diols such as poly- (pentane-1,5-carbonate) diol and poly- (hexane-1,6-carbonate) diol. It may be a copolymer such as a formed polyetherester.

Typical examples of the organic diisocyanate used in the present invention are bis- (p-isocyanatophenyl) -methane (hereinafter abbreviated as MDI), tolylene diisocyanate (hereinafter abbreviated as TDI), bis- (4-isocyanate). Cyclohexyl) -methane (hereinafter abbreviated as PICM),
Hexamethylene diisocyanate, 3,3,5-trimethyl-5-methylenecyclohexyl diisocyanate and the like. Among them, MDI is particularly preferred.

Various diamines, for example, ethylenediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine and the like are suitable as chain extenders for forming polyurethaneurea. Chain terminators can be included in the reaction mixture to help control the final molecular weight of the polyurethaneurea. Usually, it is preferable to use a monofunctional compound having an active hydrogen as the chain terminator, for example, diethylamine.

Further, the chain extender is not limited to the above-mentioned amine, and a diol may be used. For example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,2-propylene glycol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, 4-bis (β-hydroxyethoxy) benzene, bis (β-hydroxyethyl) terephthalate and paraxylylene diol. The diol chain extender is not limited to only one type of diol, and may be composed of a plurality of types of diols. Further, it may be used in combination with a compound containing one hydroxyl group that reacts with an isocyanate group. In this case, as a method for obtaining such a polyurethane, various methods such as a melt polymerization method and a solution polymerization method can be adopted. The formulation of the polymerization is also not particularly limited, for example, polyol and diisocyanate,
A method of synthesizing a polyurethane by simultaneously reacting with a chain extender composed of a diol may be mentioned, and any method may be used.

In the present invention, the polyurethane polymer is preferably used as a polyurethane solution using a solvent, is preferably used as a polyurethane dispersion using a dispersion medium, and further, a mixture of these may be used. preferable.

In the present invention, these solutions, dispersions, and mixtures thereof are collectively referred to as a polyurethane spinning stock solution (hereinafter abbreviated as stock solution). In the present invention, a solvent, a dispersion medium, and a mixture thereof are collectively referred to as a medium.

A medium such as a solvent or a dispersion medium used for dissolving or dispersing the polyurethane polymer includes:
Any material may be used as long as it is inert to the polyurethane, but N, N-
It is preferable to use dimethylacetamide (hereinafter abbreviated as DMAc), dimethylformamide, dimethylsulfoxide, vinylpyrrolidone, or the like.

Although the concentration of the stock solution is not particularly limited, it is usually preferably in the range of 25% by weight to 80% by weight.

More preferably, 30% by weight to 60% by weight.
The range is as follows, and more preferably 35% by weight or more.
The range is 5% by weight or less.

If the amount is less than 25% by weight, the amount of heat required for evaporation of a solvent or the like during dry spinning increases, and spinning tends to be difficult.

On the other hand, if the content exceeds 80% by weight, the stability of the stock solution deteriorates, as a result, the spinnability deteriorates, and if the degree of polymerization of the polymer is reduced to improve the stability of the stock solution, the yarn quality tends to deteriorate. There is.

The viscosity of the stock solution is 2500 poise or more and 5500
It is preferably equal to or less than poise. If the viscosity is 2500 poise or more, the yarn breakage due to a decrease in the viscosity during dry spinning is small, and the spinnability is good. If the viscosity is 5500 poise or less, the pressure loss at the die portion can be suppressed to some extent. Yarn quality can be improved.

The value of the viscosity is based on a steel ball drop type viscosity measurement method at 40 ° C.

In the present invention, the stock solution contains a titanium oxide pigment coated with the above-mentioned poorly water-soluble coating agent.

Further, a benzotriazole-based ultraviolet absorber, a hindered amine-based weathering agent, a hindered phenol-based antioxidant, various pigments such as iron oxide, barium sulfate, zinc oxide, cesium oxide, silver It is also preferable to include a functional additive containing ions and the like.

The polyurethane-based elastic fiber of the present invention can be obtained by spinning a stock solution. As a spinning method that can be adopted, any method such as a dry spinning method, a melt spinning method, and a wet spinning method may be used.

In the present invention, in particular, a dry spinning method can be preferably employed. Spinning conditions such as the temperature of the stock solution, the ambient temperature, the discharge speed, the shape of the die, and the yarn take-up speed during dry spinning can be appropriately selected. The number of holes in the die is preferably one or more to form one or more single yarns.

The fineness, number of filaments, cross-sectional shape and the like of the polyurethane-based elastic fiber of the present invention can be appropriately determined according to the application.

It is preferable that the treatment agent is applied to the polyurethane elastic fiber mainly in a manufacturing process such as spinning.

As the application method, a roller method, a nozzle method, a spray method and the like can be selected.

The setting property and the stress relaxation of the polyurethane-based elastic fiber of the present invention are particularly susceptible to the speed ratio between the godet roller and the winder. Therefore, it is preferable to appropriately determine the setting property according to the purpose of use of the yarn.

That is, from the viewpoint of obtaining a polyurethane-based elastic fiber having desired setting properties and stress relaxation, it is preferable that the speed ratio between the godet roller and the winder be in the range of 1.15 or more and 1.65 or less. When a polyurethane yarn having particularly high setting property and low stress relaxation is obtained, the speed ratio between the godet roller and the winder is more preferably in the range of 1.15 to 1.4, and more preferably in the range of 1.15 to 1.15. 3
A range of 5 or less is more preferred.

On the other hand, in order to obtain a polyurethane-based elastic fiber having low setting property and high stress relaxation, it is preferable that the speed ratio between the godet roller and the winder be in the range of 1.25 to 1.65. , 1.35 or more and 1.65
The following ranges are more preferable.

The spinning speed is preferably 450 m / min or more from the viewpoint of improving the strength of the obtained polyurethane elastic fiber.

[0048]

The present invention will be described in more detail by way of examples.

The arsenic content analysis method of the present invention will be described below. [Arsenic content in titanium oxide pigment] Nitric acid, sulfuric acid, hydrofluoric acid, and 2% potassium permanganate solution are added to the sample for thermal decomposition, a saturated ammonium oxalate solution is added, and the mixture is heated and allowed to cool. Add 40% potassium iodide, heat on a hot plate, allow to cool, add 10% ascorbic acid, add 1%
Add sodium borohydride, 0.5% sodium hydroxide solution, hydrochloric acid, and water to constant volume to generate arsenic hydride,
The measurement was performed using an atomic absorption spectrophotometer at a wavelength of 193.7 nm and a quartz heating cell temperature of 1000 ° C. [Arsenic content in polyurethane elastic fiber] To a sample, add nitric acid and sulfuric acid and decompose by heating, add a saturated ammonium oxalate solution, heat and cool, add 40% potassium iodide, and heat on a water bath , Allowed to cool, added 10% ascorbic acid, added 1% sodium borohydride, 0.5% sodium hydroxide solution, hydrochloric acid, water and made up to constant volume to generate arsenic hydride. Used, wavelength 193.7n
m, measured at a quartz heating cell temperature of 1000 ° C.

[Example 1] As a titanium oxide pigment, "Taipaque" (registered trademark) PF-711 manufactured by Ishihara Sangyo Co., Ltd. which was sufficiently rectified from a crude titanium tetrachloride solution was used.

The arsenic content was found to be 3 p by elemental analysis.
pm, and contained substantially no arsenic.

Bis- (p-isocyanatophenyl)-
A mixture of methane / tetramethylene ether glycol (number average molecular weight 1800) = 1.58 / 1 (molar ratio) was reacted in a conventional manner at 90 ° C. for about 3 hours to obtain a capped graphate containing 2.22% of an isocyanate moiety. Equol was prepared. This capped glycol was diluted with N, N-dimethylacetamide (DMAc). Next, a DMAc solution containing ethylenediamine and diethyleneamine was added to the DMAc solution of capped glycol, mixed at room temperature using a commercially available high-speed stirrer, chain-extended, and DMAc having a solid content of 35% by weight in the polymer was added. A solution was obtained.

To this DMAc solution, a titanium oxide-based pigment was added so as to have a content of 1.6% by weight to prepare a polyurethane spinning stock solution.

This polyurethane spinning stock solution was subjected to a polyurethane elastic fiber (44 dte) by a usual dry spinning method.
x, 4 filaments).

The spinning property of the obtained polyurethane elastic fiber was good, and no trouble such as thread breakage occurred.

Arsenic in the polyurethane-based elastic fiber was below the detection limit of 0.5 ppm, and was not detected.

Comparative Example 1 A polyurethane elastic fiber (44 dtex, 4 filaments) was wound in the same manner as in Example 1 by using a titanium oxide pigment having an arsenic content of 54 ppm by elemental analysis. Was.

The content of arsenic in the obtained polyurethane elastic fiber was as high as 2.4 ppm.

[0059]

According to the present invention, the dispersibility of a titanium oxide pigment in a stock solution for spinning polyurethane can be improved, and spinning troubles such as thread breakage can be reduced.

Claims (2)

[Claims] 1. A polyurethane elastic fiber comprising a titanium oxide pigment substantially free of arsenic. 2. A process for producing a polyurethane-based elastic fiber, comprising using a titanium oxide-based pigment substantially containing no arsenic.