JPH10158981A - Hard cotton structure improved in its fatigue resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hard cotton structure that improves fatigue resistance, solves the bottoming feel and can be effectively used as a pillow, cushion, sleeping pad. SOLUTION: As a matrix, (A) non-elastic polyester crimped staple fibers and (B) non-elastic, hot melting staple fibers comprising a polyester copolymer melting at a temperature 30-150 deg.C lower than the melting point of the polyester of the staple fiber (A) and another polyester polymer melting at a higher temperature than the melting point of the polyester copolymer are formulated at a weight ratio A/B of 90/10-50/50. At least a part of the stable fibers are fused to form a fiber structure having solidly stuck points. This fiber structure is treated with a surface treatment agent made of a polyether-ester block copolymer in an amount of 0.02-5.0wt.% based on the total weight of the crimped staple fibers (A) and composite staple fibers (B).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard cotton structure (here, a hard cotton structure is a fibrous structure using inelastic crimped short fibers as a matrix and inelastic heat-adhesive short fibers as a binder component). More specifically, in comparison with the conventional hard cotton structure, the structure of the hard cotton structure has rigidity (so-called hardness), is hard to set, and is made of a polyester fiber having no sense of bottoming. A hard cotton structure.

[0002]

2. Description of the Related Art A hard cotton structure made of synthetic fiber such as polyester is generally widely used as a core material for pillows, cushions, mattresses and the like.

[0003] The reason for this is that cotton, which has been widely used, is inferior in bulkiness and settling resistance (bulk), and generates cotton dust during web molding or when using products. This is because of poor environmental hygiene such as germination of bacteria due to excessive water absorption.

A hard cotton structure made of synthetic fibers, especially a hard cotton structure made of polyester, is
Various improvements have been made, such as adding a hydrophilic surface treatment agent to the fiber surface or imparting functions that are not found in natural fibers, in order to eliminate the disadvantages of moisture absorption and sweat absorption. (Tokuhei 1-1528
9, JP-B-5-12470, etc.).

[0005] Generally, the required property required as a hard cotton structure is settling resistance. In the present invention, the term “set” means a phenomenon in which properties such as bulkiness, rebound resilience, and compression elasticity decrease after a long-term load or repeated load is applied to a hard cotton structure, and the superiority or inferiority of a hard cotton structure product Is known as one of the important performance. In the first place, a hard cotton structure made of synthetic fibers is a three-dimensional structure obtained by heat-treating a mixed cotton web of synthetic fibers serving as a matrix and inelastic thermo-adhesive fibers serving as a binder and fusing and fixing at intersections between the fibers. The set resistance is superior to that of a mere fiber aggregate such as a natural fiber.

[0006]

However, the hard cotton structure made of polyester fiber has an excellent bulkiness immediately after the production, but the settling increases with time as it is used, so that the feeling of bottoming out is increased. However, the performance is not sufficiently satisfactory. For example, when used for the purpose of interlining of a mattress, there are problems such as local dent, floor feeling, and sinking feeling.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the surface of both the matrix and the inelastic thermoadhesive short fibers constituting the fibrous structure can be obtained. By adhering a specific amount of a surface treating agent mainly composed of a polyetherester-based block copolymer, the flow (wettability) of the polymer of the binder component is improved, and the crimping performance, especially the crimping ratio, is usually improved. By increasing the entanglement between the fibers by increasing the height of the polyester short fiber, and improving the rigidity and elasticity of the structure, compared with the conventional polyester hard cotton structure,
In terms of the settling resistance, the inventors have found that they are extremely excellent, and have completed the present invention.

That is, according to the present invention, the inelastic polyester crimped short fibers (A) as a matrix and the melting point of the polymer constituting the short fibers (A) are 30 to 150 ° C.
The inelastic thermoadhesive short fibers (B) in which the copolymerized polyester polymer having a lower melting point and the polyester polymer having a higher melting point than the copolymerized polyester polymer are arranged in a weight ratio of (A: B) = ( 90:10)-
(50:50), wherein at least a part of the short fibers are fused to each other to form a fixing point. On the fiber surface of the fiber (B), a surface treating agent containing a polyether / ester-based block copolymer as a main component is based on the total weight of the crimped staple fiber (A) and the conjugate staple fiber (B). Thus, a hard cotton structure having improved set resistance can be provided, characterized in that 0.02 to 5.0% by weight is attached.

In the present invention, a surface treating agent mainly comprising a polyetherester-based block copolymer is applied to the surface of the inelastic polyester-based crimped short fibers (A) and the inelastic heat-adhesive short fibers (B). 0.02 to 5.0% by weight based on the total weight of the crimped short fibers (A) and the composite short fibers (B) is required.

The surface treatment agent is an adhesive component at the time of thermoforming because it is present on both fiber surfaces of the inelastic polyester crimped staple fiber (A) and the inelastic thermoadhesive staple fiber (B). When the copolymerized polyester is in a molten state, compatibility with the crimped short fibers (A), flowability, and wettability are remarkably improved, and the strength of a fusion bonding point is remarkably improved.

[0011] When the adhesion amount is less than 0.02% by weight,
The above effects cannot be obtained. On the other hand, if it exceeds 5.0% by weight, there is a problem that an effect corresponding to the amount of adhesion cannot be expected and the cost is disadvantageous. When the surface treating agent is attached to only one of the inelastic polyester-based crimped staple fibers (A) or the conjugate staple fibers (B) as a matrix, the object of the present invention is to obtain a fusion bond strength. No improvement occurs.

Examples of the surface treating agent include terephthalic acid, isophthalic acid, methasdium sulfoisophthalic acid, or a polyether ester block comprising a lower alkyl ester thereof and a lower alkylene glycol, polyalkylene glycol, or polyalkylene glycol monoether. It is a copolymer and dispersed using a surfactant such as an alkali metal salt of polyoxyethylene alkyl phenyl ether phosphate, an alkali metal of polyoxyethylene alkyl phenyl ether sulfate and / or an ammonium salt or alkanolamine salt thereof. Things can be mentioned.

The above-mentioned surface treating agent is mainly used for imparting hygroscopicity and water absorbency to synthetic fibers, and is used for inelastic polyester crimp short fibers (A) and inelastic heat-adhesive short fibers (B). As described above, the compatibility of the copolymerized polyester polymer in the molten state with the crimped short fibers (A) is remarkably improved, and the strength of the fusion bonding point is remarkably increased. Furthermore, it is insufficient to attach this agent to either the crimped staple fiber (A) or the conjugate staple fiber (B). This is because it is clear that it is more advantageous that all the fibers that come into contact with the copolyester polymer in the molten state are coated with this surface treatment agent.

In the present invention, the crimp ratio of the inelastic polyester crimped short fibers (A) is preferably in the range of 30 to 40%. This is because, by increasing the number of entanglements between fibers, the number of fiber bonding points is increased, and dimensional stability (settling resistance) for maintaining a three-dimensional structure is imparted even when a load is repeatedly applied for a long period of time. Therefore, for such purposes, it is considered that other crimping performance (number of crimps), fiber length, and the like have a small effect, but a remarkable effect is particularly observed in the case of fibers having a crimping ratio in the above range.

The cross-sectional shape of the inelastic polyester crimped short fiber (A) of the present invention may be any of a circle, a flat, an irregular shape and a hollow shape. It preferably has a cross section. This means that even with the same denier, the hollow cross section has a substantially larger fiber diameter, a larger contact area with the binder component, and a bending moment (rigidity) of the fiber itself.
As a result, a structure that is harder and more resilient than when a main fiber having a solid cross section is used can be obtained.
The hollow ratio of the hollow section is preferably in the range of 15 to 40%. When the hollow ratio is less than 15%, the advantage of being hollow is hardly exhibited. On the other hand, if it exceeds 40%, there is a problem that the crimps are elongated during the thermoforming treatment and the crimped short fibers (A) themselves are sagged.

In the present invention, the inelastic polyester polymer constituting the inelastic polyester crimped short fiber (A) is a polymer of terephthalic acid or an ester-forming derivative thereof and ethylene glycol or 1,4-butanediol. That is, polyethylene terephthalate, polybutylene terephthalate, or a copolymer based on them is preferably used. Examples of the acid component to be copolymerized include aromatic dicarboxylic acids such as isophthalic acid, sulfoisophthalic acid, 5-sodium sulfoisophthalic acid, diphenyldicarboxylic acid, and naphthalenedicarboxylic acid, and aliphatic acids such as oxalic acid, adipic acid, sebacic acid, and dodecanoic acid. Oxycarboxylic acids such as dicarboxylic acid, p-oxybenzoic acid and p-β-oxyethoxybenzoic acid can be mentioned. Further, as the diol component to be copolymerized,
Aliphatic diols such as 3-propanediol, 1,6-hexanediol and neopentyl glycol;
Examples thereof include aromatic diols such as bis (β-oxyethoxy) benzene, and polyalkylene glycols such as polyalkylene glycol such as polyethylene glycol and polybutylene glycol. The third component to be copolymerized may be a single component or a copolymer of two or more types simultaneously.

On the other hand, the inelastic thermoadhesive short fibers (B) used for forming the fusion bonding points are 30 to 150 ° C. lower than the melting point of the polyester polymer constituting the crimped short fibers (A). It is necessary to provide a copolymerized polyester polymer having a low melting point and a high melting point polyester polymer represented by the polyester-based polymer constituting the crimped short fibers (A). When the above melting point difference is less than 30 ° C., the heat treatment temperature of the fusing process becomes too high during the production of the hard cotton structure, causing crimping of the inelastic crimped short fibers,
In addition, the mechanical properties of the crimped short fibers are reduced. On the other hand, if the melting point difference exceeds 150 ° C., there is a problem in maintaining the shape of the hard cotton structure when left at a high temperature. Furthermore,
The former copolymerized polyester polymer as a fusing component,
It is necessary that it is exposed at least on the surface of the composite short fiber.

If the fusion component is not exposed on the fiber surface, no heat fixation point is formed in the structure. In particular, it is preferable that the fiber is exposed so as to occupy 1/2 or more of the fiber surface. As for the ratio of the copolymerized polyester polymer and the high-melting polyester polymer in terms of weight ratio, the former and the latter are in a composite ratio of (30:70) to (70:30).
Is suitably in the range. When the melting point of the thermoplastic polymer is not clearly observed, the thermoplastic polymer is replaced with the softening point.

The cross-sectional shape of the composite short fiber (B) is as follows.
Any of a side-by-side type and a sheath core type may be used, but the latter is preferable. This sheath
In the core type, a copolyester is disposed in a sheath (sheath) portion, and a polyester polymer having a melting point higher than that of the copolyester is disposed so as to form a core (core) portion. It may be arranged in any eccentric shape. In particular, eccentric ones are more preferable because they prevent the fibers from sticking together at the spinning stage and exhibit coiled elastic crimps during stretching.

In the present invention, the weight ratio of the inelastic polyester crimped short fibers (A) and the inelastic heat-adhesive short fibers (B) constituting the hard cotton structure is expressed by weight ratio: (A: B)
= (90:10) to (50:50). If the mixing ratio of the conjugate short fiber (B) is too low, the number of fusion bonding points formed in the structure decreases, and the hard cotton structure is easily deformed. Poor properties, that is, inferior settling resistance.

On the other hand, if the mixing ratio of the conjugate short fibers is too high, the number of constituent matrix fibers giving resilience decreases, and the resilience of the structure becomes insufficient.

In producing the hard cotton structure of the present invention, first, a short fiber mass mixed at the above-mentioned weight ratio is passed through a card to obtain a uniform cotton web. In this way, innumerable fiber crossing points are formed between the inelastic polyester-based crimped staple fiber (A) and the inelastic thermoadhesive staple fiber (B) and between the conjugate staple fibers (B). Next, the web is placed in a mold so as to have a predetermined density, and the melting point of the non-elastic thermo-adhesive short fibers is lower than the melting point of the polyester polymer constituting the non-elastic polyester crimp short fibers (A). The thermoforming treatment is performed at a temperature 10 to 80 ° C. higher than the melting point of the copolymerized polyester polymer disposed as one component in (B). As a result, the copolymerized polyester polymer melts and flows and fuses at the fiber crossing point.

The conjugate short fiber (B) can be spun by a usual spinning method. At this time, the short fiber (B) is spun at a take-off speed of 500 to 1500 m / min after spinning.
It is preferable that the film is stretched twice or more. By this stretching treatment, the amorphous portion in the fiber is randomized in the process of becoming a short fiber and in a relaxed state, resulting in a fiber structure having excellent elasticity, which is easily maintained even after being melted and solidified. It has an excellent effect on settling resistance when it becomes.

[0024]

According to the present invention, the hard cotton structure made of polyester fiber has a larger number of fusion bonding points formed in the structure and has a stronger bonding point than the conventional hard cotton structure. The rigidity of the structure of the hard cotton structure is rigid since it is adhered to the surface of the body, so that the set resistance is improved and the feeling of bottoming is eliminated, so that the structure can be effectively used as a pillow, cushion, mattress or the like.

[0025]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. In addition, each value in an Example was measured by the following method.

(1) Crimp ratio: Measured according to the method described in JIS L-1015.

(2) Amount of oil applied to raw cotton: JIS L-1
According to the method described in No. 015, the measurement was carried out by an alcohol / benzene extraction method.

(3) Hardness: A 25% compression hardness according to JIS K-6401 was used. For ordinary cushion material use, there is no practical problem if the weight is 20 to 30 kg.

(4) Compression residual strain: JIS K-6401
It was measured according to the method described.

(5) 80,000 times constant strain compression durability: JIS K
According to the method described in -6401, when a constant strain is repeatedly applied 80,000 times so as to have a thickness of 50% based on the thickness under no load, and then becomes 75% of the initial thickness. Was measured for residual strain (C) and hardness retention (D).

(6) Durability under constant load compression: JIS K-6
According to the method described in No. 401, a constant load of 0.5 kg / cm ² was repeatedly applied to the sample 360 times, and then the residual strain (C) and the hardness retention (D) when the thickness became 75% of the initial thickness were applied. ) Was measured.

Reference Example 1 Production of a surface treating agent: 50 parts of polyoxyalkylene glycol having a molecular weight of 3,000 to 8,000, terephthalic acid 30
2.7 parts of polyoxyethylene lauryl ether was mixed with 10 parts of a copolyester consisting of 20 parts of ethylene glycol and 20 parts of ethylene glycol, and melted at 250 ° C. in a nitrogen stream. The mixture was adjusted with stirring to 90 parts of the aqueous solution to obtain a copolymerized polyester emulsion dispersion (surface treatment agent).

Reference Example 2 Production of inelastic thermoadhesive short fibers (B): Polymerization of an acid component obtained by mixing dimethyl terephthalate and dimethyl isophthalate at a predetermined ratio and a glycol component obtained by mixing ethylene glycol and diethyl glycol. The obtained copolyester-based polymer is disposed in a sheath component in a core-sheath type fiber, and a normal polyethylene terephthalate polymer is disposed in a core component, and the inelastic heat is adjusted so that a sheath-core ratio becomes 50:50. Adhesive fiber is taken off by a conventional method at a speed of 1100
It was manufactured at m / min. After stretching this undrawn yarn about 3.7 times, about 0.16% by weight of the surface treating agent obtained by the operation of Reference Example 1 was adhered to the fiber surface, and the fiber length was 51 mm.
Inelastic thermo-adhesive short fibers (B)
I got

Example 1 A polyethylene terephthalate polymer having an intrinsic viscosity of 0.64 was used.
A spinning temperature of 30 mm from a spinneret having 5 mm and 192 holes.
0 ° C., discharge rate 724 g / min, take-up speed 565 m / m
The melt spinning was performed by using a normal melt spinning machine with setting to be in. After stretching the obtained unstretched yarn about 4.1 times in warm water at 70 ° C., the copolyester emulsified dispersion obtained by the operation of Reference Example 1 was added to the fiber surface of the stretched yarn by about 0.1 times. After being attached at 16% by weight, a crimp is applied, and then subjected to a relaxation heat treatment at 140 ° C. for about 80 minutes, and then cut so as to have a fiber length of 64 mm to obtain an inelastic polyester-based crimped short fiber (A) of about 18 de. Was.

The crimped staple fiber (A) obtained by the above operation and the conjugate staple fiber (B) obtained by the operation of Reference Example 2 consist of 7
A web was prepared by blending cotton so as to have a weight ratio of 0:30 and a raw cotton lump was hung on a card to blend the web. The web was placed in a mold so that the density was about 30 kg / m ^3, and was placed at 160 ° C. A thermoforming treatment was performed for 20 minutes to obtain a hard cotton structure. Table 1 shows the results
And Table 2.

Example 2 In Example 1, when producing the inelastic polyester-based crimped short fibers (A), 14
A hard cotton structure was obtained by performing the same operation except that the crimped short fiber (A) having a hollow cross section (hollow ratio of 25%) was used. The results are shown in Tables 1 and 2.

[Comparative Example 1] In Example 1, a lauryl phosphate-based oil was used instead of the emulsified dispersion of the copolymerized polyester instead of the surface treatment agent to be adhered to the inelastic polyester-based crimped short fibers (A). The same operation was performed to obtain a hard cotton structure. The results are shown in Tables 1 and 2.

[Comparative Examples 2, 3, 4]
The surface treatment agent to be attached to the inelastic thermo-adhesive staple fiber (B) was changed from a copolymerized polyester emulsified dispersion to a lauryl phosphate-based oil agent, and the physical properties of the inelastic polyester crimped staple fiber (A) were shown. A hard cotton structure was obtained by performing the same operation except for changing as described in 1. The results are shown in Tables 1 and 2.

Comparative Example 5 The same procedure as in Comparative Example 2 was carried out except that the emulsified dispersion of the copolymerized polyester was replaced with a lauryl phosphate oil instead of the surface treatment agent to be attached to the inelastic thermoadhesive short fibers (B). Was performed to obtain a hard cotton structure. The results are shown in Tables 1 and 2.

[0040]

[Table 1]

[0041]

[Table 2]

In the measurement of constant strain compression and constant load compression of 80,000 times in Table 2, C represents residual strain (%) and D represents hardness retention (%).

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // D01F 6/62 301 D01F 6/62 301A

Claims (3)

[Claims] 1. A non-elastic polyester crimped short fiber (A) as a matrix, a copolymerized polyester polymer having a melting point lower by 30 to 150 ° C. than a melting point of a polymer constituting the short fiber (A), and the copolymerized polyester The inelastic thermoadhesive short fibers (B) in which a polyester polymer having a melting point higher than that of the polymer is disposed are used in a weight ratio of (A: B) = (90:10) to (50:50). In a fibrous structure which is blended and at least a part of the short fibers are fused together to form a fixing point, the fiber surface of the crimped short fiber (A) and the composite short fiber (B) Is a surface treatment agent containing a polyether / ester-based block copolymer as a main component, having a surface treatment agent of 0.02 to 0.02 based on the total weight of the crimped staple fiber (A) and the conjugate staple fiber (B).
A hard cotton structure having improved set resistance, characterized by being attached by 5.0% by weight. 2. Inelastic polyester crimped short fibers (A)
The hard cotton structure according to claim 1, wherein a crimp ratio of the hard cotton is in a range of 30% to 40%. 3. Inelastic polyester crimped short fibers (A)
Has a hollow cross-section, and the hollow ratio is in the range of 15 to 40%.