JPS6341549A - Hot-melt polyester based composition - Google Patents

Abstract

PURPOSE:To obtain the title composition, by blending a specific copolyester, acid-modified polyolefin and epoxy-modified acrylic resin, having excellent adhesive property to polyester fibers and capable of giving a flexible fibrous structure. CONSTITUTION:A composition obtained by blending 100pts.wt. total of (A) 25-75pts.wt. copolyester having 100-150 deg.C softening point with (B) 75-25pts.wt. acid-modified polyolefin having 30-300g equiv./10<6>g acid value with (C) 0-50pts. wt. epoxy-modified acrylic resin having 100-1,000g equiv./10<6>g epoxy value.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polyester composition suitable for producing hot-melt binder fibers.

(Prior art) In recent years, for the purpose of adhering constituent fibers in fiber structures such as padding cotton for futons and padding cotton for quilting,
True melt type binder fibers have come into wide use.

For example, a sheath-core type polyolefin binder fiber with a polyethylene sheath and a polypropylene core (Japanese Patent Laid-Open No. 5
(See No. 8-180614, No. 58-191215, etc.)
and binder fibers made of low softening point copolyester or polyester binder fibers having a low softening point copolyester as a sheath and a high softening point polyester as the core.
U.S. Pat. No. 4,129,675.

(See Japanese Patent Application Laid-Open No. 57-66117, etc.).

(Problems to be Solved by the Invention) The above polyolefin binder fibers are preferable when the fibers constituting the fiber structure (referred to as base fibers) are polyolefin fibers, but they have been widely used in recent years. When polyester fibers, which have become popular, are used as base fibers, they have to be used in large quantities because of their poor adhesive effect.

There was a problem that the properties of the base fiber were impaired.

In addition, the above polyester binder fiber.

When polyester fibers are used as the base fibers, a good adhesive effect is exhibited, but there is a problem that the texture of the fibrous structure after bonding becomes hard due to the characteristics of the polyester constituting the fibers.

The present invention eliminates such drawbacks of conventional binder fibers and is particularly suitable for adhering fiber structures using polyester fibers as heath fibers. It is an object of the present invention to provide a polyester composition suitable for producing a polyester binder fiber that provides a flexible fiber structure.

(Means for solving the problems) The present invention achieves the above two objects, and its gist is as follows:
Copolymerized polyester A with a softening point of 100 to 150°C 25
~75 parts by weight, 875 to 25 parts by weight of acid-modified polyolefin, and epoxy-modified acrylic resin C (total of A and B: 1
00 parts by weight) in a polyester composition consisting of 0 to 50 parts by weight.

As the copolymerized polyester A in the present invention.

A copolymerized polyester having a softening point of 100 to 150° C., which is mainly composed of ethylene terephthalate units and ethylene isophthalate units and exhibits good adhesion to polyester fibers, is preferably used.

In addition, acid-modified polyolefin B is blended to give a soft feel to the fiber structure after bonding, and is added in an amount of 75 to 2 parts by weight to 25 to 75 parts by weight of copolyester A.
It is blended in a proportion of 5 parts by weight. If the proportion of copolymerized polyester A is small, the adhesion with polyester fibers will be insufficient, and if the proportion of acid-modified polyolefin B is small, the texture of the fiber structure after adhesion will be hard.

Acid-modified polyolefin B is propylene.

Olefins such as ethylene and aliphatic monocarboxylic acids such as acrylic acid and methacrylic acid or maleic acid.

Examples include copolymers with aliphatic dicarboxylic acids such as fumaric acid. The purpose of acid modification is to improve spinnability by increasing compatibility with copolymerized polyester A, and the degree of acid modification is such that the acid value is 30 to 300 g eq/106
It is preferable to have a value of g. If the acid value is too low, the effect of improving compatibility will not be sufficient, and if it is too high, gelation will occur easily during blending or spinning, which is not preferable.

In addition, epoxy-modified acrylic resin (polyacrylate or polymethacrylate) C is blended to further improve the compatibility between copolymerized polyester A and acid-modified polyolefin B to further improve spinnability. O to 50 parts by weight are added to a total of 100 parts by weight. If this amount is too large, the proportion of copolymerized polyester A will be relatively reduced, resulting in insufficient adhesion to polyester fibers, so it is desirable to reduce the amount within a range that provides good spinnability. When using binder fibers with a large single filament fineness for spinning, the spinnability is relatively good even without this addition, so the blending amount can be reduced to 0 or extremely small, and the single filament fineness that causes poor spinnability can be reduced. In the case of spinning binder fibers with a fineness of 5 d or less, it is necessary to increase the blending amount comparatively.

Examples of the epoxy-modified acrylic resin C include copolymers of acrylate or methacrylate monomers such as methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate with small amounts of acrylate or methacrylate monomers having epoxy groups such as glycidyl acrylate and glycidyl methacrylate; Examples include copolymers in which copolymer components such as styrene and vinyl acetate are added to the components. The degree of epoxy modification is such that the epoxy value is 100 to 1000 g eq /10'
An appropriate level is g. If the epoxy value is too low, the amount to be blended must be increased; if it is too high, gelation tends to occur during blending or spinning, which is undesirable.

The copolymerized polyester A, the acid-modified polyolefin B, and the epoxy-modified acrylic resin C can be blended by tri-blending them in a mixer and subjecting them to melt-spinning, or by melt-kneading them in advance to form blended polymer chips and subjecting them to melt-spinning. This can be done by any means such as.

The polyester composition of the present invention is suitable as an adhesive component for binder fibers, and may be used as a monocomponent fiber consisting only of this composition, or as a fiber with this composition forming all or part of the fiber surface. It may also be a sheath-core type, side-by-side type, sea-island type, etc. composite fiber. However, in terms of spinnability and #i fiber property, it is most preferable to use a sheath-core type composite fiber.

In that case, the core component is polyethylene terephthalate,
It is preferable to use polyesters such as polybutylene terephthalate and polyesters mainly composed of polybutylene terephthalate, and it is particularly preferable to use polyesters containing 90 mol % or more of ethylene terephthalate units in terms of one strength property.

(Function) In the polyester composition of the present invention, the acid-modified polyolefin that is compatible with the copolymerized polyester is intimately mixed with the polyester, and the copolymerized polyester and the acid-modified polyolefin are bonded together by the epoxy group of the epoxy-modified acrylic resin. It exhibits good spinnability because it is partially crosslinked to increase the tightness of the mixture.

Also, binder fibers using this composition.

Since the copolymerized polyester in the composition has good adhesion to polyester fibers and the acid-modified polyolefin is soft, the binder fiber provides a fiber structure with a soft feel.

(Example) Next, the present invention will be specifically explained with reference to Examples.

The method of measuring characteristic values, etc. in the two examples is as follows.

Intrinsic viscosity Measured at a temperature of 20°C using an equal weight mixture of phenol and tetrachloroethane as a solvent.

soft decoy point Yanagimoto automatic melting point measuring device AMP-1 type was used.

The needle insertion temperature in the silicone bath was determined.

The non-woven fabric was cut to a width of 25n and tested using a constant speed extension type tensile tester.
Measured at a sample length of 1001 m and a tensile speed of 1001 m/min.

Measured according to the dish soft skin JIS L 109645 degree cantilever method.

A sensory test conducted by 10 panelists was conducted on a five-point scale.

1: Soft, 2: Slightly soft, 3: Average.

4: Slightly hard, 5: Hard.

Examples and Comparative Examples A copolymer polyester consisting of 60 mol% of ethylene terephthalate units and 40 mol% of ethylene isophthalate units (softening point: 110°C, intrinsic viscosity: 0.626).

The polyolefins and modified acrylic resins shown in Table 1 were mixed in the proportions shown in Table 1 in a two-screw single-type melt-kneader.
The mixture was melt-kneaded at 240°C, discharged into strands, and cut to obtain blended polymer chips.

After drying this blended polymer chip and polyethylene terephthalate (intrinsic viscosity 0.633) chip under reduced pressure,
Using a normal sheath-core type composite fiber melt-spinning device, from a spinneret with 265 spinning holes, the spinning temperature was 270°C, the output rate was 347 g/min, and the composite ratio was 1:1, so that the former would become the sheath. After cooling, it was taken off at a speed of 1000 m/min.

The obtained yarn was bundled into a 100,000 d tow and stretched at a drawing temperature of 60
It was stretched at a stretching ratio of 3.1° C., crimped using a push-in crimper, and then cut into lengths of 5111 mm.

Binder fibers with a fineness of 4d were obtained.

This binder fiber and polyethylene terephthalate crimped fiber with a fineness of 2d and a length of 51 mm were mixed in a ratio of 40:60, and passed through a card to obtain a fiber with a basis weight of 40 g/rtr.
= A web was heat-treated for 1 minute in a rotary dryer at 140°C to obtain a nonwoven fabric.

Table 1 shows the characteristic values of the obtained nonwoven fabric.

In Table 1, polyolefin ■ is maleic acid copolymerized low-density polyethylene manufactured by Mitsubishi Yuka Co., Ltd.; Mitsubishi Modisok L
-400F (softening point 116°C), and the polyolefin @ is a low-density polyethylene homopolymer manufactured by Mitsubishi Yuka;
Shows Mitsubishi Nohati Sok L-M420.

In addition, the modified acrylic resin is methyl methacrylate 59
mol%, copolymer of 38 mol% styrene and 3 mol% glycidyl methacrylate, average molecular weight approximately 30.0
00. x Phoxy value 300eq/106g (D Epoxy modified polymethacrylate (softening point 120''c).

Note that spinnability indicates the number of yarn breakages per 5 hours using 8 spindles.

Table 1 (Effects of the Invention) According to the present invention, polyester binder fibers that have good adhesion to polyester fibers and provide soft fiber structures can be produced with good spinnability. A polyester-based composition is provided.

Claims (1)

[Claims] (1) Copolymerized polyester A with a softening point of 100 to 150°C
25-75 parts by weight, acid-modified polyolefin B75-25
A polyester composition comprising 0 to 50 parts by weight of epoxy-modified acrylic resin C (based on 100 parts by weight in total of A and B).