JPS59187620A - Formed product of modified polyester - Google Patents

Abstract

PURPOSE:A formed product of modified polyester that is produced by introducing a specific amount of carboxyl group substituted with an alkali metal into the formed product composed of polyalkylene terephthalate and polyethylene terephthalate, thus showing cotton-like properties. CONSTITUTION:The objective modified polyester formed product is obtained by introducing more than 5X10<-4> gramequivalent/gram of the product of carboxyl groups substituted with an alkali metal into each filament composed of (i) polyalkylene terephthalate whose alkylene has 4 or more carbon atoms such as polybutylene terephthalate and (ii) polyethylene terephthalate. The content of the carboxyl groups is higher in the component i than in the component ii and, more preferably, the component i occupies over 30% of the surface of the formed product.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a modified polyester fiber, and more particularly to an improved polyester fiber having cotton-like properties by introducing carboxyl groups substituted with an alkali metal into the fiber.

Polyester fibers are widely recognized for their excellent wash and wear properties and other physical properties, and are being used in a wide range of outerwear fields.

Shi7 or Shi2. - Because the fiber itself is too hydrophobic, it has hardly been applied to the innerwear field that requires moisture absorption and permeability, the sanitary field such as towels and sheets, and the sports field such as sweatshirts and under sportswear. This is the reality. For this reason, the industry is making various efforts to improve the performance of polynisder fibers. For example, in Japanese Patent Publication No. 45-502 and Japanese Patent Publication No. 48-10186, a method for imparting hygroscopic properties to polyethylene fibers is described. Also! Mochikai 58-18
No. 414 proposes a method of adding moisture absorption performance to polybutylene ethylene oxide fibers. However, [7] The former has the disadvantage that the hygroscopic performance is improved, but the tenacity is greatly reduced.On the other hand, the latter can provide the hygroscopic performance with a relatively small decrease in tenacity, but the The problem is that the essential drawback of poor dimensional stability cannot be improved, but rather tends to be exacerbated.

Therefore, the inventors of the present invention have conducted intensive studies on the development of a polyester molded product having excellent moisture absorption and permeability with excellent dimensional stability, and have arrived at the present invention.

That is, one aspect of the present invention has the following configuration in order to achieve the above-mentioned object.

(1) In a molded product made of polyalkylene terephthalate and polyethylene terephthalate whose alkylene chain has 4 or more carbon atoms, the carboxyl group substituted with an alkaline earth metal is 5×10 gram equivalent/gram molded product or more. Introduced modified polyester molded products.

(2) The amount of alkali metal-substituted carboxyl groups introduced into the polyalkylene terephthalate component whose alkylene chain has 4 or more carbon atoms than the polyethylene terephthalate component of the molded product (gram equivalent/gram molded product)
The modified polyester molded article according to claim 1, characterized in that the modified polyester molded article has a large amount of.

(3) The modified polyester molding according to claim 1, wherein the polyalkylene terephthalate component whose alkylene chain has 4 or more carbon atoms occupies 30 or more parts of the surface of the molded product. Goods.

By adopting such a structure, we have succeeded in providing a cotton-like polyester molded product that has moisture absorption and permeability, has good W&W dimensional stability, and has less loss of strength than was previously possible. This is what I did.

Here, the content of the present invention will be described in more detail.

Polyalkylene terephthalate (A) in which the number of carbon atoms in the alkylene chain is 4 or more as used in the present invention, such as polybutylene terephthalate, polyhexamethylene terephthalate, etc.
．． Ester reaction products with 6-hexanediol, etc., and furthermore, 20 mol% t of these polyalkylene terephthalate structural repeating units also include those in which one unit of another chemical structural monomer is copolymerized. For example, a polymer copolymerized with several molar sulfoiphthalic acid units such as di(4-hydroxybutyl 5-sodium sulfoisophthalate) may be used as the dyeing seat.

In addition, polyethylene terephthalate (8) as used in the present invention means an ester reaction product of terephthalic acid and ethylene glycol, and like the above-mentioned polyalkylene terephthalate in which the number of carbon atoms in the alkylene chain is 4 or more, it has a repeating structure. Up to 20 mol% of the units may be copolymerized with one unit of another chemical structural monomer.

These polyalkylene terephthalates (A), (
In B), a carboxyl group substituted with an alkali metal is introduced into the single fiber in an amount of 5 x 10 gram equivalent/gram molded product or more, preferably 1.7 x 10 gram equivalent/gram molded product or more. In particular, the polyalkylene thirephthalate is used to provide cotton-like moisture absorption and permeability, but in order to prevent a decrease in tenacity and provide excellent W&W properties and dimensional stability. -b (A)
, (B) at the same time.

In such polyalkylene terephthalate molded products,
The content of carboxyl groups substituted with alkali metal is
From the viewpoint of strong retention, it is preferable to introduce more carboxyl groups substituted with alkali metals into the polyalkylene terephthalate component (A) whose alkylene chain has 4 or more carbon atoms than the polyethylene terephthalate component (B) from the viewpoint of strong retention. The introduction ratio (gram equivalent/gram molded product ratio) is
(A)/(B) -1,'5 or more is preferable from the viewpoint of achieving the object of the present invention.

Next, the molded article referred to in the present invention is a type in which a polyalkylene terephthalate component (x) whose alkylene chain has 4 or more carbon atoms and a polyethylene terephthalate component (B) are contained in a single fiber as shown in FIGS. 1 to 4. It may be a composite molded product having a structure, or it may be a blend, blend, or interweaving of independent molded products such as polyalkylene terephthalate fiber (A) and polyethylene terephthalate fiber (B), each having 4 or more carbon atoms in the alkylene chain. .

Alternate knitted fabrics may also be used. At that time, Ike's fIk fibers are mixed within the range where the effects of the present invention can be exerted (blending, mixed fibers, mixed weaving).

There is no problem even if the material is knitted with alternating knitting, etc. That is, some natural fibers such as wool and cotton may be mixed with synthetic fibers such as ordinary polyamide and polyester fibers.

On the other hand, the forms of the molded products include staple, tow, filament 9 spun yarn, force[]'T yarn 1 knitted fabric, and woven fabric.

Fiber molded products such as non-woven fabrics and sheets, and films.

Any plastic molded product is possible.

Both dyed and undyed products are suitable, and there are no particular limitations.

In addition, in the molded article of the present invention, the above-mentioned alkali metal-substituted carboxyl group was introduced inside the single fiber (A)
When component (B) is present, it is better to manufacture the product so that component (A) occupies more than 60% of the surface of the single fiber silk. It is preferable to obtain a cotton-like polyester molded article having the following properties. The second method for introducing a carboxyl group substituted with an alkali metal into a molded product is when manufacturing a molded product such as fiber.

When polymerizing a polymer, a method is used in which a polymer such as acrylic acid or methacrylic acid is blended and then spun, or after a molded article such as a fiber that has not been introduced with an alkali metal-substituted carboxyl group is manufactured in advance. By graft polymerizing monomers such as acrylic acid and methacrylic acid,
There are methods such as replacing it with an alkali metal after that.
The former method has problems such as gelation and is difficult to industrialize, so the latter method using graft polymerization is preferred. However, since the molded product will be graft-polymerized later, if there is more polyethylene terephthalate component (B) on the surface of the molded product, the 9 strength and low F will be large, making it difficult to achieve the object of the present invention. Therefore, in the molded article of the present invention, the polyalkylene terephthalate component (A) whose alkylene chain has 4 or more carbon atoms must occupy at least 30 parts, preferably 50 parts or more, of the surface of the molded product.

In addition, two graphs referred to in the present invention!・Polymerization refers to cases where a polymer of monomers having vinyl groups and carboxyl groups is chemically bonded to the polyester molded product (A), (J3) as a graft polymer chain, and when the polymer is a polyester-based molded product (A) or (J3). This includes both cases where the polymer enters the amorphous part of the molded product (A) or (B) and is homopolymerized there.

Examples of the organic carboxylic acid having a vinyl group in the present invention include the aforementioned hydrophilic monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, butenetricarboxylic acid, and these monomers may be used alone or Two or more types may be mixed. Furthermore, acrylamide, methacrylamide, N-methylol acrylamide, 2-hydroxyethyl acrylate, 2-
It may be used in combination with monomers such as hydroxyethyl methacrylate-1., 3-hydroxypropyl methacrylate.

The content of the carboxyl group substituted with the alkali metal salt is preferably 5 x 10 gram equivalent/gram molded product or more, preferably 17 x 10'', in order to achieve cotton-like moisture absorption and permeability.
It is necessary to introduce more than "gram equivalent/gram molded article, but if it is less than that, good moisture absorption and permeability cannot be achieved.

2 Examples of the step of introducing a carboxyl group substituted with an alkali metal into the polyester molded article according to the present invention by graft polymerization include staple, tow, filament l-, spun yarn, and processed yarn.

Fabrics may be produced at any stage, but polyalkylene terephthalate molded products (A) in which the number of carbon atoms in the alkylene chain is 4 or more and polyethylene terephthalate molded products (B)
), when compounding them using mixed fibers, blended yarns, two-way knitting and weaving, graft polymerization is performed on each molded product in advance.
Mixed knitting or knitting may be used. After forming a 1-dimensional mixed fiber, blended, or mixed or knitted fabric, graft polymerization may be performed to control the carboxyl group content of the 9-color component."It's better.

2.The cotton-like properties mentioned in the present invention9 For example, polybutylene terephthalate fiber has an official moisture content of 04 and has no groove absorbing properties, whereas cotton has an official moisture content of 8.5 and has antistatic properties. Polybutylene terephthalate fiber has the general physical and chemical properties of cotton that it does not have, such as having no problem with practical properties or combustibility being of the carbonized type, or it has been modified to have properties similar to it. However, the most characteristic feature is that it has thermoabsorption properties.

Any method can be used to graft polymerize the organic carboxylic acid monomer. That is, a dipping method in which polybutylene terephthalate fibers are immersed in an aqueous solution containing the organic carboxylic acid monomer and heated in a bath, and a method in which the polybutylene terephthalate fibers are pulled up after dipping and squeezed to a desired liquid content, and then heated with steam or dry heat. Patching method.

Radiation methods using gamma rays and electron beams, electricity, and ozone oxidation methods are used.

Among the treatment methods described in 1., the dipping method is recommended as the most desirable method in order to best exhibit the effects of the present invention such as graft polymerization efficiency. That is, in the immersion method, the object to be treated is immersed in an aqueous solution containing a monomer at a bath ratio of 1:200 or less and heated to 70 to 120°C. Generally, polymerization can be carried out without using a polymerization initiator, but if necessary, a radical polymerization initiator such as benzoyl peroxide or azobisbutyronitrile can be dispersed with a surfactant in a treatment bath containing an organic carboxylic acid monomer. Alternatively, a two-bath method may be used in which the initiator is pretreated and activated, and then treated with an aqueous organic carboxylic acid monomer solution.

Here, the desired content of carboxyl groups can be obtained by appropriately increasing or decreasing the amount of the organic carboxylic acid monomer used.

Next, after graft polymerization, the grafted carboxyl group is subjected to a substitution treatment with a metal salt. Examples of the metal salts include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, thorium carbonate, sodium bicarbonate, potassium carbonate,
Examples include alkali metal salts of inorganic weak acids such as 2-sodium phosphate, and alkali metal salts of organic acids such as sodium acetate and sodium propionate. Particularly preferred are sodium carbonate and sodium hydrogen carbonate, which may be used alone or in combination of 92 or more.

The amount of the metal salt used is usually in the range of 0.1 to 10 g/7.
This is achieved by heat treatment for 10-30 minutes in a ~80°0 bath.

The present invention will be specifically explained below with reference to Examples.

Note that each measurement value used in the examples is measured using the following method.) Sample fibers are heated and dissolved in benzyl alcohol, purified chloroform is added, and the fibers are cooled. Next, add the phenol red-alcohol solution and immediately add the alkaline solution for titration with the sodium hydroxide-alcohol solution.
--Standardized using trobenzoic acid.

(2) Moisture absorption rate (related) The sample fiber was placed in a weighing bottle, and after being left at 110°C for 2 hours and 24 hours, the weight was accurately measured again and calculated using the following 13-general formula. It is good if the moisture absorption rate is 30I) or more.

Most preferably, it has a coefficient of 8.5 or higher, which is comparable to cotton fiber.

Example 1. Comparative Example 1.2 Using a temporarily twisted yarn of a mixed yarn (150 denier, 48 filament drawn yarn) consisting of 50% polybutylene terephthalate and 50% polyethylene terephthalate,
A 28-gauge circular knit jersey (interlock structure, basis weight 150 g/m') was knitted, scoured and dried by a conventional method, and then heat set.

This jersey contains 10 g/l of acrylic acid and 1 g/l of methacrylic acid.
0 [! ;/'l monochlorobenzene 5 g/l,,, / immersed in an emulsified dispersion consisting of benzoyl peroxide 2 g/l as an agent so that the bath ratio was 1=25, and heated at 100°
The temperature was raised to C and heat treatment was performed for 60 minutes. Next, after washing with water, 60
°09 Filtered for 0 minutes, washed with water and dried. This chassis had moisture absorption properties comparable to those of cotton based on carboxyl groups. In addition, the strength of this jersey was 87% lower than before graft polymerization, making it a highly practical knitted fabric.

Furthermore, we calculated the shrinkage rate when this chassis was washed 95 times using normal household washing (neutral detergent Zabu 2g/)', bath ratio 1 knee 50, 40°C x 5 minutes, 9 rinses 5 minutes x 2 times). I checked and found that the vertical direction is 17 and the horizontal direction is 2.
It was found that the chassis is small with 7 sections and has high dimensional stability.

Next, as a comparison, nine 150 tenier, 4B filament drawn yarns made only of polybutylene terephthalate were knitted, knitted, grafted, and treated with alkali in the same manner as in this example (Comparative Example 1).

Each of the products consisting only of polyethylene terephthalate 1 (Comparative Example 2) had the characteristics evaluated in the same manner as in Example 1, and '! Also, the strength is 90% compared to before graft polymerization.
Although the degree of decrease was low, the shrinkage during washing was 52% in the vertical direction and 11% in the horizontal direction, making it impractical.

A value close to that was obtained, and the washing shrinkage was 15% in the vertical direction and 22% in the horizontal direction, resulting in a product with good dimensional stability, but the strength was significantly reduced by 52% compared to before graft polymerization. It became sexless.

Example 2 A multifilament drawn yarn (1
50 tenier, 48 filaments) was woven into a twill fabric (grain size 220 g/m').9
After scouring and drying by a conventional method, heat setting was performed.

This fabric was subjected to graft polymerization and alkali treatment under the same conditions as in Example 1 to obtain a fabric with a moisture absorption rate of 84%. The degree of decrease in strength of this fabric before and after grafting was as low as 85%, and the shrinkage after 5 times of trench washing was 20% in the vertical direction and 29% in the horizontal direction, making it highly practical.

Further, as a reference, when the cross section of the fiber after grafting was dyed with a cationic dye, the 9-sheath component was dyed very darkly, but the core component was dyed lightly, clearly proving that the sheath component contained a large amount of carboxyl groups.

[Brief explanation of drawings]

FIGS. 1 to 4 are cross-sectional views of polyester single fibers that are an example of the molded product of the present invention. In the figure, 1 indicates a polyenalene terephthalate component, and 2 indicates a polyalkylene terephthalate component in which the alkyl group has 4 or more carbon atoms. Figure 4

Claims (2)

[Claims] (1) In a molded product made of polyalkylene terephthalate-I, whose alkylene chain has 4 or more carbon atoms, and polyethylene terephthalate, 5×10 gram equivalents/gram of alkali metal-substituted carboxyl groups are molded. Modified polyester molded products introduced above. (2) The amount of alkali metal-substituted A-nicarboxyl groups introduced into the polyalkylene terephthalate component whose alkylene chain has 4 or more carbon atoms than the polyethylene terephthalate component of the molded product (gram equivalent/gram molded product) The modified polyester molded article according to claim 1, characterized in that the modified polyester molded article has a large amount of. (The modified polyester according to claim 1, characterized in that the polyano 1-kylene derephthalate 1-1 component whose alkylene chain has 4 or more carbon atoms occupies the surface of the molded product north of the 50th column. molded products.