JPS5844767B2 - Manufacturing method of polyurethane elastic yarn - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyurethane elastic yarn with improved unwinding properties, running smoothness and resistance to chlorine deterioration.

Originally, polyurethane elastic thread has poor unwinding properties when wound onto a bobbin due to its adhesiveness, making it difficult to unwind, and it also causes a lot of friction with guides etc. during use.
Does not run easily.

In order to improve such unwinding properties and running smoothness, it is common practice to apply an oil agent.

Various ideas have been made regarding the oil agent used, but the definitive one has not yet been known.

Particularly in recent years, due to improved productivity in the processing field, the traveling speed of elastic yarn has increased significantly, often reaching 300 m/min.

When the running speed is 100 m/min or less, it is possible to solve problems such as unwinding property and running smoothness to a large extent by selecting an appropriate lubricant even with highly sticky elastic yarn, but especially at 100 m/min.
When running at high speeds of more than 1 minute, current lubricants cause yarn sway due to the ease with which the elastic yarn stretches even with slight tension fluctuations.
For example, in the warping process, threads come into close contact with neighboring threads, causing frequent thread breakage during passage of liquid.

In order to solve this problem, there have been attempts to increase the amount of oil applied, but this not only increases costs but also causes various problems such as the oil seeping out after warping and staining the case and the product. There is.

The present inventors have conducted extensive research to solve these problems, and as a result, have arrived at the present invention.

That is, the present invention is a method for producing polyurethane elastic thread by dry spinning a solution of polyurethane obtained by reacting a polymer diol with a molecular weight of 600 or more and a melting point of 60° C. or less, an organic diisocyanate, and a bifunctional active hydrogen compound with a molecular weight of 400 or less. In Japanese Patent Publication No. 40-5557, which is characterized in that 0.005 to 5 parts by weight of metal soap is blended with respect to polyurethane in the solution at a stage before spinning, fatty acids containing about 8 to 22 carbon atoms are used. and metals of Group Ia of the Periodic Table with an atomic weight of between about 7 and 133, metals of Group I of the Periodic Table with an atomic weight of between about 24 and 137, and metals of Group Ia of the Periodic Table with an atomic weight of about 27. A method has been proposed in which a salt of a metal selected from the group consisting of metals of the genus genus is blended into an oil solution in the form of a fine powder with an average radius of 0.5 to 2% by weight in the range of 0.05 to 5μ. However, this method is not sufficiently effective, and scum is significantly generated at the guide and other contact parts of the yarn during use.

According to the present invention, since the unwinding property and running smoothness are significantly improved by adding it to the polyurethane solution, there is no problem even when running at high speed.

Of course, there are no drawbacks such as generation of scum on guides or contamination by products.

What is even more surprising is that an elastic yarn with excellent resistance to chlorine deterioration can be obtained.

It is also characteristic that these effects cannot be obtained by wet spinning, but can only be obtained by dry spinning.

The polyurethane referred to in the present invention includes polymer diols, organic diisocyanates, and organic diisocyanates having a molecular weight of 600 or more, preferably 1000 to 8000, and a melting point of 60°C or less.
It is obtained by reacting a difunctional active hydrogen compound of 0 or less.

Examples of polymer diols include polyether glycols such as polytetramethylene ether glycol and polyethylene/propylene ether glycol, and glycols such as ethylene glycol, 4-butanediol, neopentyl glycol, and 1,6-hexanediol.
Polyester glycols, polycaprolactone glycol, polyhexamethylene, which contain one or more species and one or more dicarboxylic acids such as adipic acid, superric acid, azelaic acid, sebacic acid, β-methyladipic acid, and isophthalic acid. Examples include dicarbonate glycol and the like, or a mixture or copolymer of two or more thereof.

In addition, examples of organic diisocyanates include 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-phenylene diisocyanate,
Examples include 2.4-h lylene diisocyanate, hexamethylene diisocyanate, 1°4-cyclohexane diisocyanate, 4j4'-dicyclohexylmethane diisocyanate, inphorone diisocyanate, or a mixture of two or more thereof.

Examples of difunctional active hydrogen compounds include ethylenediamine, l,
2-propylene diamine, hexamethylene diamine, xylylene diamine, 4,4'-diphenylmethane diamine, hydrazine, 1,4-diaminopiperazine, ethylene glycol, 1°4-i tanediol, 1,6-hexanediol, water, etc. or a mixture of two or more thereof.

Particularly preferred are diamines. Examples of solvents for polyurethane include N,N-dimethylformamide, N,N-dimethylacetamide, tetramethylurea, and hexamethylphosphonamide.

Usually 1.5 to 3.0 per mole of polymer diol
Moles of organic diisocyanate are reacted in the presence or absence of a solvent to obtain a prepolymer having incyanate groups at both ends.

In this case, a catalyst that promotes the reaction, such as a tertiary amine or a tin compound, or an acidic negative catalyst may also be used.

Next, a chain extension reaction is performed in the solution state using a bifunctional active hydrogen compound to obtain a polyurethane solution.

The method for obtaining these polymers is not essential to the present invention, and the polymer diol, organic diisocyanate, and bifunctional active hydrogen compound may be reacted simultaneously, or each may be divided and reacted in several stages. You can also do it.

The metal soap used in the present invention is an aliphatic carboxylic acid salt having 8 to 30 carbon atoms of a metal from Group 1 and/or Group 2 of the periodic table. at least 0.1 g/dl
It is preferable that the solubility is .

Specifically preferred metals include magnesium, zinc, and aluminum, and preferred fatty acids include lauric acid, myristic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, and arachidic acid.

All metal soaps have good unraveling properties, but group II metal salts in particular have excellent smoothness when running at high speeds, and group II metal salts have somewhat excellent smoothness when running at low speeds, so they are used over a wide range of applications. In order to provide excellent running smoothness, it may be preferable to use both in combination.

The amount used is usually 0.005 to 5 parts by weight, preferably 0.05 to 1 part by weight, based on the polyurethane.

Below this range, the improvement effect on unwinding property and running smoothness is sufficient; on the other hand, when it exceeds the above range, not only the excellent physical properties of the elastic yarn such as elongation, strength, stress, etc. are reduced, but also Scum accumulates on guide reeds, knitting needles, etc. during running, causing problems in subsequent processes.

The timing of adding the metal soap is not particularly limited as long as it is at a stage before spinning, but it is preferably added after the prepolymer reaction or after the polymerization is completed.

Further, the form of the metal soap is not particularly limited, but since it hardly dissolves in a solvent at room temperature, in order to obtain uniformity, the particle size is usually 30 μm or less, preferably 10 μm or less.

In the present invention, addition of hindered phenols, hindered amines, ultraviolet absorbers, tertiary amine compounds, gas discoloration inhibitors, pigments such as titanium oxide, etc., which are usually added to polyurethane, is not hindered. Can be used together.

The present invention provides significant effects only in dry spinning.

The reason for this is not clear, but it is effective for metal soaps that are soluble in the polyurethane solvent at least at a temperature below the spinning temperature. During spinning, the metal soaps move with the solvent to the surface or near the surface, resulting in polyurethane elastic threads. This is thought to be due to the formation of a film or highly concentrated layer of metal soap on the surface of the metal soap.

Dry spinning of polyurethane is usually carried out at 180°C to 280°C, preferably 200°C to 250°C.

The spun yarn is false twisted and coated with an oil agent.

The type of oil agent is not particularly limited, but in addition to commonly used dimethylpolysiloxane, diorganopolysiloxane in which a portion of the methyl group is substituted with other alkyl groups or phenyl groups, epoxy groups, amine groups, vinyl groups, etc. Preferably, an oil agent containing an organopolysiloxane such as the modified polysiloxane introduced therein or mineral oil as a main component is preferable.

In particular, a straight oil mainly composed of organopolysiloxane is particularly suitable for polyurethane using polyester diol as a soft component.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

In addition, the evaluation of unwinding property, running smoothness, and chlorine deterioration resistance in the present invention was carried out by the following method.

(1) Put the cheese wrapped with elastic thread on the unwinding feed roller, put the thread on the take-up roller, fix the rotation speed of the feed roller, and vary the rotation of the pick-up roller so that the filament rolls onto the feed roller. If the rotational speed of the pick-up roller at that time is A1 and the feed roller speed is B, then it is expressed by the following equation.

(2) Running smoothness (running friction coefficient) The smoothness of a filament when running can be evaluated by the friction coefficient of the yarn against the friction surface of the knitting needle.

The measurement was performed using F-Meter R-1182 manufactured by Keizoku Kogyo Co., Ltd., and the measurement principle is as follows.

That is, as shown in FIG.
When the thread is moved at a constant speed in the direction of ■, the tensile tension t
1 becomes larger than t2.

This force difference (1, -12) is the force used to overcome the friction force, and the friction coefficient is expressed by the following equation.

The speed can be changed from Om/min to 500m/min.

Example 1 Polyester glycol (adipic acid: ethylene glycol: 1,4-
A prepolymer reaction is performed by adding 50% dimethylformamide to a polymer produced by copolymerizing butanediol (copolymer with a molar ratio of 10:6:4) and 4,4'-diphenylmethane diisocyanate with a molar ratio of 1:2.5. followed by a chain extension reaction with 1°2-propylene diamine,
A polyurethane solution having a viscosity of 2000 poise at a polymer concentration of 30 parts was obtained.

To this solution was added the metal soap shown in Table 1 in a weight ratio of 10 to the polyurethane, and the mixture was stirred for 90 minutes to obtain a spinning dope.

After degassing the spinning stock solution under vacuum, it was extruded into a spinning tube in which heated air at 220°C was flowed through a nozzle with a diameter of 0.2 mrn and 25 holes, and false twisting was performed at a rotation speed of 1000 r, P, m, and the mineral A polyurethane elastic thread was obtained by applying oil and dimethylpolysiloxane-based oil to the thread at a density of 4070, and then winding the thread at a spinning speed of 300 m/min.

In addition, as a comparison sample, a polyurethane elastic yarn without the addition of metal soap was produced in the same manner.

The unwinding property and running smoothness of the obtained elastic yarn were measured, and the results shown in Table 1 were obtained.

As is clear from the table, the unwinding property and running smoothness can be significantly improved by adding metal soap.

Example 2 A prepolymer reaction was performed with polytetramethylene ether glycol having a molecular weight of 1300 having hydroxyl groups at both ends and 4,4'-diphenylmethane diisocyanate in a molar ratio of 1:2, and then with 1,2-propylene diamine. The chain extension reaction was carried out at 2000 at a polymer concentration of 30%.
A polyurethane solution with a viscosity of Poise was obtained.

In this solution, the ratio of magnesium stearate O to polyurethane, 0.05, 0.1, 0.5, 1.0,
5.0 and 10 parts were added and stirred to obtain a spinning dope.

After vacuum debinding, the spinning stock solution was extruded into a spinning cylinder with 180°C heated air flowing through a nozzle with a diameter of 0.2 mm and 25 holes, and false-twisted at a rotation speed of 11,000 rpm. A polyurethane elastic yarn was obtained by applying four coats of oil to the yarn and then winding it at a spinning speed of 500 m/min.

A scum test was conducted to examine the unwinding properties and running smoothness of the obtained polyurethane elastic yarn.

What is the scum test? Rotate the feed roller at 50 m/min and the pick-up roller at 200 m/min, thread the polyurethane elastic thread, and place a safety razor blade at right angles to the thread between the feed roller and the pick-up roller. The purpose of this test is to compare the amount of adhesive that sticks to a razor blade when rubbed for a certain period of time.

Table 2 shows the evaluation results.

Metallic soap has a remarkable effect on unwinding properties and running smoothness, but if the amount is too small, it will not be effective, and if it is too good, it will cause the disadvantage that a large amount of scum will be generated.

Example 3 140 d polyurethane elastic yarns with different amounts of magnesium stearate were produced in the same manner as in Example 1, and their chlorine resistance was evaluated.

The results are shown in Table 3.

The chlorine resistance was evaluated by measuring the tensile strength after treatment in a sodium hypochlorite aqueous solution containing 1600 ppm of available chlorine at pH 11 at 30°C for 17 hours, and expressing the tensile strength as a strength retention rate.

It is clear from Table 3 that the addition of magnesium stearate also significantly improves the chlorine resistance.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a test method for measuring the running friction coefficient of the polyurethane elastic yarn used in the present invention.

Claims (1)

[Claims] 1. Polyurethane elastic yarn is produced by dry spinning a solution of polyurethane obtained by reacting a polymer diol with a molecular weight of 600 or more and a melting point of 60° C. or less, an organic diisocyanate, and a bifunctional active hydrogen compound with a molecular weight of 400 or less. 1. A method for producing polyurethane elastic yarn, characterized in that 0.005 to 5 weight ratio of metal soap to Polyturekne is blended into the solution at a stage before spinning. 2 Metallic soap is at least 0.17 to polyurethane solvent at spinning temperature! The method for producing a polyurethane elastic thread according to claim 1, which is a metal soap having a solubility of /dl.