JP3468341B2 - Thermal adhesive polyester fiber - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat-bondable polyester fiber. Furthermore, the cushion material made of the fiber obtained by thermoforming using the heat-adhesive fiber of the present invention is a heat-adhesive polyester fiber capable of imparting excellent cushioning property and sag resistance.

[0002]

2. Description of the Related Art Currently, metal springs, urethane foam, polyester fiber stuffed cotton, and resin cotton or polyester hard cotton to which polyester fibers are bonded are known as cushioning materials for furniture and beds.

However, although urethane foam has good durability as a cushion, it has a large feeling of flooring, is poor in moisture permeability and has heat storage property, and is apt to be stuffy, and its calorific value upon combustion is large, and toxic gas is generated. There are problems that the incinerator is seriously damaged and that removal of toxic gas is expensive. Further, in the polyester fiber-stuffed cotton, since the fibers are not fixed, the shape of the cotton is collapsed during use, or the fibers are moved to cause crimping, which causes a problem of a decrease in bulkiness and a decrease in elasticity.

Resin cotton having polyester fibers bonded with an adhesive, for example, rubber latex used as an adhesive, is disclosed in JP-A-60-11352 and JP-A-61-1413.
88, JP-A-61-141391 and the like. In addition, as one using urethane, Japanese Patent Laid-Open No. 61-13
7732 and the like. These cushioning materials have problems that they are inferior in durability, cannot be recycled, and contain harmful components in combustion gas generated during combustion.

Polyester hard cotton, for example, JP-A-58-3
1150, JP-A-2-154050, JP-A-3-220354, etc., but since an amorphous polymer whose adhesive component of the heat-adhesive fiber used is brittle (for example, JP-A-58-58). Japanese Patent No. 136828, JP-A-3-
However, there is a problem that the bonded portion is poor in durability such that the bonded portion is plastically deformed or broken during use to be deformed or the elasticity is lowered. As an improved method, a method of entanglement treatment has been proposed in Japanese Patent Laid-Open No. 4-245965, but there is a problem that the brittleness of the bonded portion is not solved and the elasticity is largely reduced. Further, there is a problem that it is difficult to impart soft cushioning properties. Therefore, a heat-bonded fiber using a polyester elastomer which is soft at the bonded portion and easily recovers even when deformed is disclosed as an improved method in JP-A-4-2402.
No. 19 publication is proposed. The polyester elastomer used for this fiber contains 50 to 80 mol% of terephthalic acid as the acid component of the hard segment and 30% of polyalkylene glycol as the soft segment.
To 50% by weight, and as the other acid component, for example, isophthalic acid or the like is added as in the fiber described in Japanese Patent Publication No. 60-1404 to increase the non-crystallinity so that the melting point is 180 ° C. or less. It has been proposed to keep the heat-bonding molding temperature low and to lower the molecular weight to lower the melt viscosity to improve the fluidity and improve the formation of the heat-bonded portion. However, with such an adhesive composition, it is easy for plastic deformation,
During thermoforming, the flowability of the polyester elastomer is so good that it does not stop on the surface of the heat-bonded fiber and forms a core part, but a beam with only a brittle inelastic component connects between the matrix fiber of the fiber structure and the contact point, and a large force or There is a problem that the brittle inelastic component beam that easily connects the joint points is broken by the deformation, and the cushioning property and durability of the fiber structure are lost. Further, since the polyester elastomer covers the surface of the fiber, the friction coefficient of the fiber becomes too high, and the card passing property is significantly lowered. In order to improve the durability, a proposal of a heat-bonding fiber using a polyester elastomer containing no amorphous component as a heat-bonding component is proposed in JP-A-6-272111, but the friction coefficient becomes high. The card openability was slightly inferior.

[0006]

DISCLOSURE OF THE INVENTION The present invention has improved the above-mentioned problems of the prior art, and thermal bonding capable of producing a comfortable and comfortable cushioning material having excellent cushioning property and durability with good processability. The purpose of the present invention is to provide a functional polyester fiber.

[0007]

Means for Solving the Problems The present invention has been achieved as a result of intensive studies to solve the above problems. The present invention provides a basic backbone units of the polyester, an aromatic dicarboxylic acid der Ru acid component having 1 or 2 benzene rings, - (CH _{2) n}
- Polyester A (elastomer melting point n number polycondensation glycol component of the diol is odd from 3 to 7 methylene groups is 80 ° C. or higher 235 ° C. or less represented by
Except for a sheath component, the basic skeleton unit of the polyester is an acid component whose main component is an aromatic dicarboxylic acid having 1 or 2 benzene rings, and the n number of the methylene group represented by — (CH ₂ ) _n — A composite fiber having a sheath core cross-sectional shape, which comprises a core component of polyester B having a melting point higher than that of polyester A by 30 ° C. or more by polycondensing a glycol component having an even number of diols of 2 to 6 as a main component, Weight ratio of sheath to core is 30:70 to 7
It is a heat-adhesive composite polyester short fiber (hereinafter, may be simply referred to as a heat-adhesive polyester fiber) characterized by being 0:30. More specifically, it is a thermoadhesive composite polyester short fiber characterized by having crimps, or has a hollow portion and a hollow rate of 1% or more and 10% or more.
Thermoadhesive composite polyester characterized in that
It is a short fiber.

Polyester A as the sheath component of the present invention
It is the basic backbone units of the polyester, an aromatic dicarboxylic acid der Ru acid component having 1 or 2 benzene rings, alkylene glycol - (CH _{2) n} - _n number of methylene groups in a straight chain moiety represented by the 3 7 odd and is grayed <br/> melting point recall component polycondensing diols from is a polyester at 80 ° C. or higher 235 ° C. or less. For example, polypropylene terephthalate, polypropylene isophthalate, polypentamethylene terephthalate, polypentamethylene naphthalate, polypentamethylene biphenylate, polyheptamethylene terephthalate, polyheptamethylene naphthalate, polyheptamethylene biphenylate, etc. are used as repeating basic skeleton units. A single component polymerized polyester can be exemplified. The sheath component in the present invention needs to function as a heat-bonding component, and needs to be lower than the melting point of the core component by at least 30 ° C. or more. The appropriate melting point varies depending on the core component, but it is at least 235 ° C or lower and 80 ° C or higher. If the temperature exceeds 235 ° C, a versatile polyester such as polyethylene terephthalate cannot be used as the core component, which is not preferable. If it is less than 80 ° C, the heat resistance is extremely lowered, which is not preferable. The melting point of the range that can be melt-bonded in a temperature range where general equipment can be used due to heat treatment conditions and has durability and heat resistance is 100 ° C. or more and 200 or more.
℃ or less, more preferably 110 ℃ or more 180
It is below ℃. Since the polyester in which the n number of the methylene group forming the skeleton of the glycol component is 2, 4, or 6 is poor in elasticity, when the polyethylene terephthalate / polyethylene isophthalate copolymerized polyester in which the n number is 2 is used, the adhesion point is It becomes brittle and inferior in durability. Since polybutylene terephthalate having an n number of 4 has poor elasticity, when the block copolymerization of polyether is made into an elastomer to give elasticity, the surface friction of the fiber becomes extremely high and the process passability during processing is extremely reduced. However, the quality is not stable and a product with many spots is obtained, which is not preferable. On the other hand, odd-numbered polyesters with n number of 3, 5 and 7 have elasticity, and since the coefficient of friction of the fiber surface does not increase remarkably like an elastomer, good processability is maintained and stable quality is maintained. A cushioning material having excellent durability and cushioning properties can be obtained. As the preferred sheath component of the present invention, a single component having higher crystallinity is more preferable, and a component which becomes amorphous by copolymerization or addition for adjusting the melting point is preferable because it is easily plastically deformed by deformation when formed into a fiber structure. Absent. The polyester A of the present invention may contain an aliphatic acid component, a branched diol, an oligomer, and other components in an amount of less than 30 mol% in order to adjust the melting point, as long as the characteristics are not significantly deteriorated.

As the polyester B constituting the core component of the present invention, the basic skeleton unit of the polyester is an acid component containing an aromatic dicarboxylic acid having 1 or 2 benzene rings as a main component and-(CH ₂ ) _n- . The melting point obtained by polycondensation of a glycol component whose main component is a diol in which the n number of the methylene group shown is an even number of 2 to 6 is 30 ° C higher than that of polyester A.
This is a polyester having a high melting point. If the melting point difference with the sheath component is less than 30 ° C., the sheath melting temperature at the time of thermal bonding is melted at a temperature higher by 10 to 30 ° C. than the melting point of the sheath portion, and the core portion is also melted due to temperature unevenness or variation, which is not preferable. Preferred melting point difference is 50 ° C or higher, 200 ° C
The temperature is below, more preferably below 80 ° C and below 150 ° C.
If the melting point difference exceeds 200 ° C., the sheath component is decomposed during spinning, which is not preferable. Although it depends on the sheath component used, the polyester B used in the present invention includes, for example, polyethylene terephthalate, polyethylene 2.6 naphthalate, polyethylene 2.7 naphthalate, polyethylene biphenyl, polybutylene terephthalate, polybutylene 2.6 naphthalate, polybutylene 2 -Single or multi-components such as 7 naphthalate, polybutylene biphenyl, polyhexamethylene terephthalate, polyhexamethylene 2.6 naphthalate, polyhexamethylene biphenyl, polycyclohexylene terephthalate, polycyclohexylene 2.4 naphthalate, polycyclohexylene biphenyl, etc. The thing which has a copolyester as a main component can be illustrated. Polyester B has a high melting point because it has the function of a beam connecting fiber structures as a core component function, and a highly crystalline one has high modulus and heat resistance and is difficult to plastically deform. It is particularly preferable because the hardness is improved. On the contrary, it is not preferable that it is easily plastically deformed and has poor heat resistance. Also, when an elastic elastomer with excellent heat resistance and durability is used as the core component, the function of a beam with elasticity can be expressed to give heat resistance and excellent cushioning property to the cushioning material. preferable. A preferred polyester elastomer is, for example, a hard segment of the above polyester, and a soft segment having an average molecular weight of 3
An example is a ternary block copolymerized polyester obtained by block copolymerizing 00 to 5000 (preferably 500 to 3000, more preferably 1000 to 2000) polyether glycol, polyester glycol, polycarbonate glycol and the like. When the content of the soft segment in the present invention is too large, the melting point is lowered, so that the content is preferably 50 mol% or less. The preferred content is 5 mol%
It is above 30 mol%.

The polyester A and the polyester B constituting the heat-adhesive polyester fiber of the present invention may optionally contain an antioxidant, a light-proofing agent, an ultraviolet absorber, a flame retardant, an antibacterial agent, a mildew-proofing agent, inorganic particles, and coloring. A function can be added by containing an agent or the like.

The constituent weight ratio of polyester A: polyester B constituting the heat-adhesive polyester fiber of the present invention is 3
It is from 0:70 to 70:30. When the content of the sheath component is less than 30% by weight, the amount of the molten polymer supplied to the bonding points decreases, the bonding point strength decreases, and the durability decreases, which is not preferable. Furthermore, the core cannot be completely wrapped during the composite spinning, the number of bonding points is reduced, and the durability of the fiber structure is reduced, which is not preferable. When the sheath component is 70% by weight or more, the beam function of the core component deteriorates and becomes too soft, so that it becomes difficult to adjust the hardness. The preferred weight ratio of polyester A: polyester B is 40:60 to 60: 4.
It is 0, more preferably 45:55 to 55:45.

The heat-adhesive fiber of the present invention may be used in a filament form when it is made into a fiber structure, but it is usually cut by application of mechanical crimp and then cut into short fibers, which are mixed with matrix fibers to open a card. A method of forming a cushion material by thermoforming after fiber is the mainstream, and the fiber of the present invention is also used in the same manner. For that purpose, it is necessary to give crimp and cut it into short fibers. The crimping is generally performed by applying a mechanical crimp by indenting crimping after spinning and drawing. In order to maintain the card opening property and the entanglement property of the opening web, the mechanical crimping form has a crimping degree of 10% to 30% and a crimping number of 10
Peaks / inch to 25 peaks / inch are preferred. The cut length is adjusted to an appropriate length in relation to the cut length of the matrix fiber to be mixed. Usually, the length is 20 mm to 185 mm, preferably 28 mm to 65 mm, which is suitable for polyester used as a general-purpose matrix. On the other hand, when the air-through method is used as the opening method, it is preferably 10 mm to 65 mm. In the case of the air through method, it can be used without crimping, and the fiber of the present invention can be selected from crimped and non-crimped fibers. When it is used for papermaking where crimping is not required, it is preferably 5 mm to 20 mm in consideration of dispersibility.

The fiber of the present invention can form a hollow portion as a means for reducing the weight. It is preferable that the hollow portion is formed in the core portion so that when the fiber structure is formed, it acts as a beam having a hollow cross section to cause the second moment of area effect. The hollow ratio is preferably 1% or more and less than 10%. If it is less than 1%, the hollow effect cannot be expected. When it is 10% or more, the hollow structure of the core component is ruptured, the hollow effect is lost, the core is easily twisted, and the rigidity of the beam function deteriorates. A preferable hollow ratio is 3% or more and 8% or less.

The fineness of the fiber of the present invention is not particularly limited, but if the fineness is too large, the number of constituents in the case of a fiber structure decreases, the network structure becomes coarse and it becomes difficult to disperse the force. On the other hand, when the fineness of the matrix fiber is large, if the fineness of the heat-adhesive polyester fiber is too thin, it is difficult to mix and it becomes difficult to form a uniform network structure. Preferably, the fineness compatible with the matrix fiber is 1 denier or more and 100 denier or less. Moreover, the cross-sectional shape of the fiber is not particularly limited, but a round cross-section or a modified cross-section can be selected according to the application or purpose. Since the oil agent of the fiber of the present invention is exposed to high temperature due to the heat-bonding treatment, it is preferable that the oil agent has good heat resistance. For example, it is preferable to use a phosphate salt such as potassium lauryl phosphate or potassium cetyl phosphate.

The heat-adhesive polyester fiber of the present invention may be used alone as a fiber aggregate such as a non-woven fabric or a cushioning material, but the heat-adhesive polyester fiber is 5% by weight or more, preferably 30% by weight or more and 60% by weight. A preferred cushioning material can be obtained by blending with the matrix fiber to form a fiber aggregate. Examples of preferable composition of the matrix fiber include high melting point and highly crystalline polyester such as polyethylene terephthalate, polyethylene naphthalate, polycyclohexylene dimethyl terephthalate, and polyethylene biphenyl, and polybutylene terephthalate. Since a fiber structure in which a network structure is formed by using such a matrix fiber and the fiber of the present invention as a heat-bonding fiber, the bonding point has elasticity and little plastic deformation, it recovers even when subjected to a large deformation and usually has sag resistance. It is much better than that of the non-elastomer type heat-bonding component. Further, it exhibits the same settling resistance as the one using the elastomer-based heat-adhesive component, and the one using the elastomer as the core component of the present invention causes a large deformation of the entire network structure, resulting in the deformation of the heat-adhesion component and the core component. Then, since the deformation of the structure is absorbed, the sag resistance is remarkably improved.

[0016]

Examples (Examples 1 to 3 and Comparative Examples 1 to 3) Dimethyl terephthalate (DMT) or acid dimethyl terephthalate (DMI) or naphthalene 2.6 dicarboxylic acid (DMN) and ethylene glycol as a glycol component. (EG), propylene glycol (PG), butanediol (BD), pentamethylene glycol (P
D) was charged together with a small amount of a catalyst and a stabilizer, and transesterification reaction was carried out by a known method, followed by polycondensation while heating and decompressing to obtain polyester A and polyester B. The characteristics of the obtained polyester are shown in Table 1.

[0017]

[Table 1]

Using the obtained polyester A as the sheath component and polyester B as the core component, the spinning temperature is from 275 ° C. to 295 at a sheath / core weight ratio of 50/50 by a conventional method.
Unstretched yarn was obtained by spinning at 0 ° C. Then stretching temperature 70 ℃
After stretching from 3 to 3.5 times at 120 ° C and converging, mechanical crimping is applied with a crimper, and the mechanical crimping is supplied to the cutter with a tension that does not extend and cut into 51 mm and 4 denier to 4 A thermally bonded fibrous polyester fiber of 0.5 denier was obtained. The properties of the fibers obtained are shown in Table 2.

[0019]

[Table 2]

30% of the heat-adhesive polyester fiber obtained was used.
PET having a hollow density of 13% by weight and a standard weight of 3 denier and three protrusions on the outside and having a three-dimensional crimp
70% by weight of short fibers (fiber length 51 mm, number of crimps 18 threads / inch, crimping degree 23%) was mixed with a card, and the web obtained by opening the fibers had a density of 0.04 g / lippo centimeter. It was compressed so that hot air at 150 ° C. to 240 ° C. was forcibly penetrated and heat-treated for 10 minutes to obtain a flat cushion material having a thickness of 5 cm. The characteristics of the obtained cushion material are shown in Table 3. In addition, compressive residual strain of 70 ℃ (70 ℃
Strain) and cyclic compression residual strain (repetitive strain) at room temperature are J
According to the method of IS-K-6401. The card passability is indicated by good: ◯, slightly bad: Δ, and bad: × by visual judgment. The cushioning property was sensory-evaluated by allowing 10 panelists to sit, and evaluated as good: ◯, slightly poor: Δ, poor: ×.

[0021]

[Table 3]

Examples 1 to 3 satisfying the requirements of the present invention show excellent durability and good cushioning properties. In Comparative Example 1 which is out of the present invention, the core portion of the heat-adhesive fiber is melted and the cushioning property is inferior, and in Comparative Examples 2 and 3 in which the heat-adhesive component is out of the present invention, the durability is inferior.

(Examples 4, 5 and Comparative Examples 4, 5) A1 was used as the sheath component, B1 was used as the core component, and the sheath core ratio (weight ratio) was changed to obtain the heat obtained under the same conditions as the above method. The properties of the adhesive polyester fiber are shown in Table 4.

[0024]

[Table 4]

A cushion material was prepared in the same manner as in Example 1 and the evaluation results are shown in Table 5.

[0026]

[Table 5]

In Comparative Examples 4 and 5 in which the sheath score ratio is out of the range of the present invention, durability and cushioning property are poor.

Comparative Example 6 DMT as an acid component, BD as a glycol component, and polytetramethylene glycol (PTMG) as a soft segment were charged together with a small amount of a catalyst and a stabilizer and polycondensed by a conventional method to give a soft segment content of 56% by weight. %, And the melting point was 181 ° C. to obtain a polyether ester block copolymer. The obtained copolymer was used as a sheath component and PET as a core component (sheath / core weight ratio: 5
(0/50) Spun at 280 ° C., stretched at 75 ° C., then crimped and cut into 51 mm, 4 denier, 18 crimps / inch, 13% crimp Got An attempt was made to webbing the obtained fiber with a card in the same manner, but the friction coefficient was high and it was not possible to successfully open the web. Therefore, an open web was prepared by air through and treated with hot air at 200 ° C. to obtain a flat cushion material having a thickness of 5 cm. The cushioning material thus obtained had a good cushioning property with a strain at 70 ° C. of 18% and a cyclic strain of 5%. However, the passability of the card is extremely poor and the productivity is poor. The cushion material obtained by using the heat-adhesive polyester fiber of the present invention is suitable for vehicles, ships, furniture, beds, mattresses, cushions, etc., but is particularly suitable for vehicle seats such as automobiles and railways. . Further, as other uses, it can be widely applied to non-woven fabrics utilizing stretchability, such as sanitary materials, shoulder pads, base fabrics of synthetic leather and napped fabrics, stretchable knitted fabrics and the like.

[0029]

EFFECTS OF THE INVENTION According to the present invention, when another fiber is used as a matrix and heat-bonded to a cushioning material or the like, a three-dimensional network structure is formed at the bonding points having stretchability between the matrix fibers, resulting in excellent durability. It becomes possible to provide cushioning properties. Further, the productivity is remarkably good as compared with the case of using the thermoplastic elastomer, so that it becomes possible to provide the heat-adhesive polyester fiber having excellent versatility.

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Claims (3)

(57) [Claims] 1. A basic backbone units of the polyester, an aromatic dicarboxylic acid der Ru acid component having 1 or 2 benzene _{rings, - (CH 2) n -} n number of methylene groups represented by the 3
To Polyester A (excluding elastomer) having a melting point of 80 ° C. or higher and 235 ° C. or lower, which is obtained by polycondensing a glycol component of an diol that is an odd number of 7 to 7, and the basic skeleton unit of polyester has 1 or 2 benzene rings An acid component containing an aromatic dicarboxylic acid as a main component, and-(C
Polyester B having a melting point obtained by polycondensing a glycol component containing, as a main component, a diol in which the number of methylene groups represented by H ₂ ) _n- is an even number from 2 to 6 is 30 ° C. or more higher than that of the polyester A as a core. A thermoadhesive conjugate polyester staple fiber, which is a conjugate fiber having a sheath core cross-sectional shape as a component, wherein a weight ratio of a sheath portion to a core portion is 30:70 to 70:30. 2. A crimped product having a crimp.
The heat-bondable composite polyester staple fiber described. 3. The thermoadhesive composite polyester short fiber according to claim 1, which has a hollow portion and a hollow ratio of 1% or more and 10% or less.