JPH01280071A - Modification of polyester fiber - Google Patents

Abstract

PURPOSE:To impart a moisture-absorbing property to a polyester fiber without accompanying the lowering of the physical properties, hand feeling and dyeing fastness of the fiber by graft-polymerizing a hydrophilic vinylic monomer to the polyester fiber obtained by spinning the polyester at a specific spinning rate. CONSTITUTION:A polyester is spun at a spinning rate of >=7000m/min to provide a polyester fiber, then an acidic group-having vinylic monomer capable of being converted to a metal salt thereof such a acrylic acid, methacrylic acid or vinyl sulfonic acid is graft-polymerized to the above polyester fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for modifying polyester fibers by graft polymerization.

<Prior Art> Various attempts have been made to graft polymerization as a chemical modification of polyester fibers.

Most conventional methods involve applying a radical initiator to vinyl monomers or performing graft polymerization by high-energy irradiation.

However, when ordinary polyester fibers are used, the utilization rate of monomers, that is, the grafting efficiency, is low;
Therefore, it has drawbacks such as problems in wastewater treatment due to additives and homopolymers.

<Problems to be Solved by the Invention> As a result of repeated research to solve the above-mentioned problems of the prior art, the present inventors have found that by using polyester fibers spun at a spinning speed of 7000 m/min or higher, It has been discovered that the grafting efficiency is better than that of polyester fibers, leading to the present invention.

Means for Solving the Problems> That is, the present invention is a method for modifying polyester fibers, which is characterized by graft polymerizing a vinyl monomer to polyester fibers spun at a spinning speed of 7000 m/min or more.

The polyester fiber referred to in the present invention is obtained by a known polymerization method and consists essentially of polyethylene terephthalate. For example, the manufacturing method is disclosed in Japanese Patent Application Laid-Open No. 57-12161.
3, and its physical properties are as stated in the same publication.It is a fiber consisting essentially of polyethylene terephthalate with an initial modulus of 50 g/d or more, and its physical properties are as follows: Loss tangent (tan δ
) has a peak temperature of 110°C or less, and the peak value (
Disclosed are fibers in which (tan δ) II lax, ) is 0.135 or less. Regarding the fiber form, filament, staple, tow, sliver type, knitted fabric, woven fabric, etc.
Any form may be used, but from the viewpoint of processing operations, fabrics are preferred.

The graft polymerization method referred to in the present invention is an application of a known technique similar to the polymerization method for producing polyethylene terephthalate. That is, the initiator may be benzoyl peroxide and its derivatives, azobisisobutyronitrile and its derivatives, or light energy, and monochlorobenzene, benzyl Lubricants such as, but not limited to, alcohol, tetrachloroethane, and nitrobenzene can be used.

Furthermore, for the graft polymerization process, well-known methods are applied, such as immersion heating method, pad-cure method and/or
Any method can be applied, such as a pad-steam method.

Monomers referred to in the present invention include acrylic esters, methacrylic esters, vinyl pyridine, vinyl acetate, acrylonitrile, etc. Particularly hydrophilic monomers include acrylic acid, methacrylic acid, vinyl sulfonic acid, vinyl pyrrolidone, acrylamide, and methacrylamide. The monomer is not limited to these as long as it contains a vinyl group, and hydrophilic vinyl monomers are preferably used. Particularly preferred are vinyl monomers having acidic groups that can be converted into metal salts, representative examples of which are acrylic acid, methacrylic acid, and vinyl sulfonic acids.

<Example> The present invention will be explained below with reference to Examples.

The moisture absorption rate, grafting rate, and grafting efficiency shown in the examples are based on the following methods.

Moisture absorption rate; Moisture absorption rate (χ) = (humidified weight of sample - bone dry weight of sample) /
Absolute dry weight of sample, left for 2 months under humidity control conditions of 20°C x 65% RH.

Grafting rate; Grafting rate (χ) = (bone dry weight of grafted sample - bone dry weight of unprocessed sample) / bone dry weight of raw sample Grafting efficiency (χ) = (bone dry weight of grafted sample) Bone dry weight - Bone dry weight of unprocessed sample)/Amount of monomer charged All bone dry weights are determined by vacuum drying at 50° C. for 24 hours.

Example A mixture of 1 part by weight of benzoyl peroxide, 8 parts by weight of monochlorobenzene, and 2 parts by weight of a nonionic surfactant (Blysurf A-2172 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
o parts by weight of water to form an emulsion, which was used as a graft polymerization bath.

Regarding the treated fabric, ordinary polyethylene terephthalate was spun at a spinning speed of 7000 m/min and, for comparison, 2000 m/min, and 10 knitted fabrics were obtained.

These 10 knitted fabrics were added to the aforementioned graft polymerization bath at a bath ratio of 1:150.
The mixture was mashed with water, predetermined amounts of acrylic acid and methacrylic acid were added in the same volume ratio, and the mixture was heat-treated at 105° C. for 60 minutes in a stainless steel sealed container. After processing, remove the fabric and
A time clear water treatment was performed. The fabric after the water conduction treatment was treated, if necessary, in a 0.5% Na, CO, aqueous solution at 80° C. for 30 minutes.

The results are shown in Table 1 and graft efficiency after water transfer treatment, and Table 2 shows N a z CO! A comparison of the moisture absorption rate after treatment according to the spinning speed is shown.

Table 1 Table 2 <Effects of the Invention> When polyester fibers are modified by the method of the present invention, the grafting efficiency is improved, so the amount of hexamer used is reduced, and the processing cost is reduced. Furthermore, since homopolymer production is suppressed, the impact on water quality in the wastewater treatment process is reduced. Furthermore, when a hydrophilic vinyl monomer containing an acidic group is used and converted into a metal salt, the hygroscopicity is higher than that of ordinary polyester fibers even at the same grafting rate, so hygroscopicity can be achieved with a lower grafting rate. Therefore, deterioration of physical properties, hardening of hand, and deterioration of color fastness due to reduction in graft ratio can be suppressed.

Patent applicant: Asahi Kasei Industries, Ltd.

Claims (1)

[Claims] A method for modifying polyester fibers, which comprises graft polymerizing a vinyl monomer to polyester fibers spun at a spinning speed of 7,000 m/min or more.