JP2002363825A - Polyurethane elastic fiber and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve dispersibility of a titanium oxide pigment in a polyurethane spinning solution and reduce spinning trouble such as yarn breakage. SOLUTION: This polyurethane elastic fiber is characterized as comprising the titanium oxide pigment coated with a sparingly water-soluble coating agent.

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 a polyurethane-based elastic fiber capable of improving the dispersibility of a titanium oxide-based pigment in a polymer and improving spinnability, 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] Titanium oxide pigments are generally classified, dried and pulverized in the final production process to produce products. During drying, solid solutions and aggregated particles are formed, and such coarse particles remain to form a dispersion medium. It deteriorates dispersibility.

[0005] In order to improve dispersibility, attempts have been made to mechanically pulverize with a ball mill, colloid mill, zet mill or the like.

However, the dispersibility of the titanium oxide pigment in the undiluted polyurethane spinning solution is not satisfactory, and spinning problems such as thread breakage have been a problem.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyurethane-based elastic fiber having good spinnability despite containing a titanium oxide-based pigment, 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, the present invention is a polyurethane-based elastic fiber comprising a titanium oxide-based pigment coated with a poorly water-soluble coating agent.

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

That is, the present invention provides a method for producing a polyurethane elastic fiber, comprising spinning a stock solution containing a titanium oxide pigment coated with a poorly water-soluble coating agent.

[0012]

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

In the present invention, as the titanium oxide pigment,
Titanium dioxide pigment, diluted titanium oxide pigment (composite titanium oxide pigment), titanium oxide-based solid solution pigment (TiO ₂ −
Sb ₂ O ₃ —NiO-based yellow pigment) and the like are preferable.

In the present invention, as a poorly water-soluble coating agent, a carboxylic acid having 8 or more carbon atoms and a polyhydric alcohol leave at least one hydroxyl group of the polyhydric alcohol from the viewpoint of improving dispersibility in a raw polyurethane spinning solution. -Linked alcoholic ester and higher 1 having 10 or more carbon atoms
At least one selected from the group consisting of polyhydric alcohols is preferred.

As the alcoholic ester, monoesters of glycols such as ethylene glycol monomyristyl ester and propylene glycol monolauryl ester; monoesters of glycerin such as monolaurin, monobalminan, monolinolein, distearin, 1-myristo-2-stearin, Erislit monoester, diester, triester, pentaerythritol monooleyl ester, pentaerythritol caprylauryl ester, pentaerythritol tristearyl, etc. Monoesters, diesters and triesters of pentaerythritol, such as esters, and arabbit monostearyl ester A rabbit di Val Michiru ester,
Arabic monoesters, diesters, triesters, tetraesters and the like, such as arabic trivalmicyl ester and arabic tetralauryl ester, are preferably used.

As the higher monohydric alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, dodecanol-2, oleyl alcohol, linolenyl alcohol and the like are preferably used.

In the present invention, as a method of coating a titanium oxide pigment with a poorly water-soluble coating agent, the pigment is immersed in a solution of the poorly water-soluble coating agent in a solvent, and then the solvent is evaporated and dried. A method in which a solution of the poorly water-soluble coating agent is sprayed on the titanium oxide pigment and then the solvent is removed and dried, or a method in which the poorly water-soluble coating agent is formed into fine particles in a liquid state and mixed with the titanium oxide pigment is preferably employed. ,
In particular, after stirring and mixing the titanium oxide pigment and the liquid poorly water-soluble coating agent in an aqueous medium, the titanium oxide pigment is separated,
A drying method is preferably employed.

In the present invention, from the viewpoint of completely removing the coarse particles and further improving the dispersibility in the polyurethane spinning stock solution, the titanium oxide pigment coated with the poorly water-soluble coating agent is subjected to a high-speed gas injection method. Pulverization with a pulverizer is preferably performed.

Such a high-speed gas-jet-type pulverizer is characterized in that a high-speed jet of high-pressure air, steam or other gas jetted from a nozzle is applied to a titanium oxide-based pigment, and between the pigment particles, between the pigment particles and the machine wall. It refers to one that is finely pulverized by the action of collision or friction between them.

In the present invention, from the viewpoint of preventing the color of the titanium oxide pigment from being stained as compared with before the pulverization, the frictional portion of the high-speed gas-jet pulverizer has metal oxides, carbides, nitrides and the like. It is preferable to use a structural material mainly composed of a material, boride or silicide.

Examples of such a structural material include oxides such as aluminum, magnesium, silicon, zirconium, beryllium, thorium, lithium and titanium, zirconium, titanium, thorium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, uranium. Preferred are those mainly composed of carbides, nitrides, borides or silicides, such as hard porcelain, alumina-silica-based porcelain, zirconia-silica-based porcelain, and magnesia, which are fired at a high temperature from feldspar, quartz or the like. -Special ceramics such as alumina-silica porcelain, magnesia-alumina porcelain, lithium oxide-alumina-silica porcelain,
Heat-resistant porcelain such as viroceram obtained by microcrystallization of glass, and those having high hardness such as garnet, rhodolite and agate are preferably used. These structural materials preferably have a hardness of 7 Mohs or more.

The polyurethane-based elastic fiber of the present invention refers to 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 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, etc., 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, 4-butanediol, neopentyl glycol,
1,2-propylene glycol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol,
1,4-bis (β-hydroxyethoxy) benzene, bis (β-hydroxyethyl) terephthalate and paraxylylene diol. The diol chain extender is 1
The diol is not limited to only one kind of diol, and may be composed of plural kinds 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. No particular limitation is imposed on the formulation of the polymerization.For example, a method of synthesizing a polyurethane by simultaneously reacting a polyol and a diisocyanate with a chain extender composed of a diol, and the like, may be used. Good.

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

If the content 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, such a stock solution contains a titanium oxide pigment coated with the poorly water-soluble coating agent.

Further, a benzotriazole-based UV 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 are added to the stock solution. It is also preferable to include a functional additive containing ions and the like.

The polyurethane 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, a dry spinning method can be particularly 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 also preferable to add a silicone-based or mineral oil-based fiber treatment agent to impart smoothness and antistatic properties.

It is preferable that the application of the fiber treating agent to the polyurethane-based elastic fiber is performed mainly in a production process such as spinning.

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

The setting properties and stress relaxation of the polyurethane elastic fiber of the present invention are particularly susceptible to the speed ratio between the godet roller and the winder, and thus are preferably determined appropriately according to the intended 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 to 1.65. 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 is 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.

[0052]

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

Example 1 42% of rutile titanium dioxide
5 m ³ of the aqueous slurry dispersed and contained at a concentration of 0 g / l was placed in a tank equipped with a turbine stirrer, and while sufficiently stirring, the erythrit dimyristyl ester (about 39% by weight of the erythrit dimyristyl ester, about 10 wt.
% By weight and about 25% by weight of a triester).
5 kg was added, and this was further heated to 60 ° C. for about 3
Stir well for 0 minutes.

After filtering and drying the titanium dioxide treated with the coating agent, the frictional portion is finely pulverized by using a high-speed gas overflow pulverizer, which is a structural material whose surface is baked and coated with alumina-magnesia porcelain, using heated steam as a high-speed gas. Then, a titanium oxide pigment having an average particle diameter of 0.25 μm was prepared.

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 wound up with a polyurethane elastic fiber (44 dtex, 4 filaments) by a usual dry spinning method.

The number of yarn breaks during spinning is 0,0 per hour.
The number was as low as 01 times, and the spinnability was good.

[Comparative Example 1] A high-speed gas overflow, which is a structural material in which the rutile-type titanium dioxide used in Example 1 was filtered without being coated and dried, and then the friction portion was baked and coated with alumina-magnesia porcelain. Finely pulverized using heated steam as a high-speed gas with a pulverizer, and has an average
It was prepared as a 5 μm titanium oxide pigment.

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.

The polyurethane spinning solution was wound up with polyurethane-based elastic fibers (44 dtex, 4 filaments) by a usual dry spinning method.

The number of yarn breaks during the spinning is 0.
More than three times, the spinnability was poor.

[0064]

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.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Nishikawa 1-2-1 Sonoyama, Otsu City, Shiga Prefecture Toray Dupont Co., Ltd. Shiga Plant F-term (reference) 4L035 BB02 BB06 BB11 GG04 JJ05 KK01 KK03 KK05 MH03

Claims (3)

[Claims] 1. A polyurethane elastic fiber comprising a titanium oxide pigment coated with a poorly water-soluble coating agent. 2. The hardly water-soluble coating agent is an alcoholic ester in which a carboxylic acid having 8 or more carbon atoms and a polyhydric alcohol are bonded to each other while leaving at least one hydroxyl group of the polyhydric alcohol, and a higher alcohol having 10 or more carbon atoms. The polyurethane-based elastic fiber according to claim 1, wherein the polyurethane-based elastic fiber is at least one selected from the group consisting of polyhydric alcohols. 3. A method for producing a polyurethane-based elastic fiber, comprising spinning a stock solution containing a titanium oxide-based pigment coated with a poorly water-soluble coating agent.