JP3475225B2 - Core-sheath type composite fiber for binder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core-sheath type composite fiber for a binder, which is used for a cushion, a base cloth and the like and has excellent elasticity and vibration damping properties.

[0002]

2. Description of the Related Art Cushion materials are mainly used for bedding, furniture,
It is used for vehicle seats such as vehicle seats and automobile seats, and polyurethane foam has been commonly used as a cushioning material. However, Freon gas is often used in the production of polyurethane foam, and toxic cyan gas is easily generated when polyurethane foam is burned, and since landfilling is difficult and cannot be recycled, pollution and destruction of the global environment occur. I have a problem. Moreover, since polyurethane foam has a feeling of dryness on the floor and a large amount of stuffiness, when used as a cushioning material, it does not feel comfortable to sit in or sleep on, and it tends to give a sticky and unpleasant feel, resulting in poor comfort. There is.

Therefore, instead of the polyurethane foam having the above-mentioned drawbacks, stuffed cotton made of synthetic fiber such as polyester cotton has been used as a cushioning material and a base cloth. A method is used in which binder fibers are mixed and thermoformed to form a cushion material. However, when a cushioning material is manufactured using polyester fibers, it is possible to impart some stretchability by improving the fiber material, but good cushioning properties, such as elasticity recovery, can be applied to these cushioning materials, base fabrics, etc. It was extremely difficult to impart the property. Attempts have been made to compensate for such drawbacks by using an elastomer such as rubber having good elastic properties as a fiber material.However, it is extremely difficult to fiberize an elastomer such as rubber, and it is possible to spin it. However, there has been a problem that fibers are completely stuck together by winding and the like, and even if an oil agent or the like is applied to the fiber surface to prevent sticking, sticking cannot be prevented sufficiently.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a core-sheath type composite fiber for a binder, which is excellent in elasticity and vibration damping properties.

That is, according to the present invention, in a composite fiber in which two kinds of thermoplastic polymers are arranged in a core-sheath type over the entire length of the fiber, the thermoplastic polymer constituting the core component is a conjugated diene polymer. It is a block copolymer composed of block B and aromatic vinyl polymer block A, and is a heat-sensitive resin that constitutes the sheath component.
The plastic polymer has a melting point of 200 ° C. or less and an acid component
Containing 20 to 50 mol% isophthalic acid
It is a terpolymer and has a composite ratio of core component and sheath component (core /
It is a core-sheath type composite fiber for a binder, characterized in that the sheath is 20/80 to 80/20.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The block copolymer constituting the core component in the core-sheath type composite fiber of the present invention includes a polymer block A mainly containing an aromatic vinyl compound and a polymer mainly containing a conjugated diene compound. A block copolymer composed of block B is hydrogenated so that 70% or more, preferably 80% or more, and particularly preferably 90% or more of the aliphatic double bonds based on the conjugated diene are saturated bonds, preferably ,
It is a block copolymer having a number average molecular weight of 30,000 to 300,000. If the hydrogenation rate (hydrogenation rate) is less than 70%, thermal deterioration is likely to occur during melt spinning, and the weather resistance of the resulting fiber is also poor, such being undesirable. When the molecular weight is less than 30,000, mechanical properties such as strength and elongation of the core component itself are deteriorated and properties of the fiber itself are deteriorated, which is not preferable. On the other hand, when it exceeds 300,000, the viscosity increases, spinning becomes unsatisfactory, and the performance also deteriorates. The range of 50,000 to 250,000 is preferable.

Examples of the aromatic vinyl compound constituting the polymer block A include styrene, α-methylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 3
-Methyl styrene, 4-propyl styrene, 4-cyclohexyl styrene, 4-dodecyl styrene, 2-ethyl-4-benzyl styrene, 4- (phenyl butyl) styrene and the like, but most preferred is styrene. One block of the aromatic vinyl polymer block A is 250
Number average molecular weight of 0 to 50,000, especially 5,000 to 400
It is preferable to have a number average molecular weight of 00, and a molecular weight of 2
If it is less than 500, the cohesive force of the polymer is lowered, and the rubber-like expansion and contraction performance and the vibration damping performance are insufficient, and it tends to be difficult to obtain the target fiber. On the other hand, the molecular weight is 50,000
If it exceeds, the melt viscosity of the block copolymer becomes too high, the thermoplasticity is impaired, and spinning tends to be difficult. The content of the block A is 10 to 50% by weight, preferably 10 to 50% by weight. Styrene content is 1
If it is less than 0%, the moldability and heat resistance will be poor, and the mechanical properties of the target block copolymer will be insufficient. On the other hand, when the content of the block A exceeds 50% by weight, stretchability and flexibility are deteriorated, and the viscosity is remarkably increased, so that the spinning condition is deteriorated and the object of the present invention cannot be achieved.

As the block B of the block copolymer used in the present invention, 1,3-butadiene,
Although there are blocks composed of isoprene, pentadiene, hexadiene, etc., isoprene or isoprene-butadiene is preferably used in combination in the present invention. The block made of isoprene is
It may be mainly composed of 4 bonds, or may have many 1, 2 bonds or 3, 4 bonds. In the present invention, when 1,4 bonds are 70% or more, elastic properties are remarkably exhibited. Also, the content of 3,4 bonds and 1,2 bonds is 4
When it is 0% or more, the peak of the main dispersion of tan δ appears at 0 ° C. or more, and the vibration damping characteristics become remarkable. Further, the form of block B when isoprene-butadiene is used in combination may be random, block or tape. Moreover, one number average molecular weight of the block B is preferably about 10,000 to 200,000, particularly preferably about 15,000 to 130000, and the molecular weight is 1
When it is less than 0000, it is not preferable because the elastic property is deteriorated.
On the other hand, when it exceeds 200,000, the melt viscosity of the block copolymer becomes high, which causes spinning failure.

The block form of the block copolymer in the present invention is represented by A (BA) n and (AB) n. Here, A is a block made of an aromatic vinyl monomer, B is a block made of a conjugated diene monomer, for example, isoprene or isoprene-butadiene, and n is an integer of 1 or more. Of these, the one in the form of ABA is most preferably used.

The copolymer composed of the block A and the block B can be produced by various known methods. For example, first, (a) a method of sequentially polymerizing an aromatic vinyl compound, isoprene or isoprene butadiene using an alkyllithium compound as an initiator, (b) an aromatic vinyl compound, and then isoprene or isoprene-
Examples thereof include a method of polymerizing butadiene and coupling it with a coupling agent, or a method of sequentially polymerizing isoprene or isoprene-butadiene with a dilithium compound as an initiator and then an aromatic vinyl compound. Examples of the alkyl lithium compound include alkyl compounds having an alkyl residue having 1 to 10 carbon raw yarns, and methyl lithium, ethyl lithium, pentyl lithium and butyl lithium are particularly preferable. Dichloromethane, dibromomethane, dichloroethane, dibromoethane, dibromobenzene and the like are used as the coupling agent. Examples of the dilithium compound include naphthalenedilithium and dilithiohexylbenzene. The amount used is determined according to the required molecular weight, but is generally 0.01 to 0.2 parts by weight of the initiator and 0.04 to 0.8 parts by weight of the coupling agent with respect to 100 parts by weight of all the monomers used for the polymerization. Used in the range of parts.

In order to make the content of 3,4 bonds and 1,2 bonds as 40% or more as the microstructure of the isoprene or isoprene-butadiene portion, a Lewis base is used as a cocatalyst during the polymerization of isoprene or isoprene-butadiene. Used. Examples of Lewis bases are ethers such as dimethyl ether, diethyl ether and tetrahydrofuran, glycol ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether, triethylamine, N, N, N ′, N′-tetramethylethylenediamine, N-methylmorpholine. And amine compounds such as The amount of these Lewis bases used is about 0.1 with respect to the number of moles of lithium in the polymerization catalyst.
It is used in the range of 1 to 1000 times. It is preferable to use a solvent for easy control during the polymerization. As the solvent, a Yuki solvent which is inert to the polymerization catalyst is used. In particular, aliphatic, alicyclic and aromatic hydrocarbons having 6 to 12 carbon atoms are preferably used. Examples thereof include hexane, heptane, cyclohexane, methylcyclohexane, benzene and the like. The polymerization is carried out in the temperature range of 0 to 80 ° C. for 0.5 to 50 hours in any polymerization method.

By subjecting the resulting block copolymer to a hydrogenation reaction, if necessary, a part or all of the carbon-carbon double bonds in the block composed of isoprene or isoprene-butadiene are hydrogenated. For the hydrogenation reaction, a method of reacting hydrogen in a molecular state with a known hydrogenation catalyst in a state of being dissolved in a solvent inert to the reaction and the catalyst is preferably used. As the catalyst used, a heterogeneous catalyst such as Raney nickel, or a metal such as Pt, Pd, Ru, Rh, or Ni supported on a simple substance such as carbon, alumina, or diatomaceous earth, or a transition metal and an alkylaluminum compound A Ziegler type catalyst comprising a combination of an alkyl lithium compound and the like is used. The reaction is carried out at a hydrogen pressure of normal pressure to 200 kg / cm ² , a reaction temperature of normal temperature to 250 ° C., and a reaction time of 0.1 to 100 hours. After the reaction, the block copolymer may be obtained by coagulating the reaction solution with methanol or the like and then heating or drying under reduced pressure, or by pouring the reaction solution into boiling water to azeotropically remove the solvent and then heating or drying under reduced pressure. Is obtained by

In the present invention, it is important not to separate the core component and the sheath component. Therefore, an olefin compound may be contained in the sheath and core components, or may be contained in both the core and sheath components. However, in view of migration of the olefin compound to the fiber surface, heat resistance, etc. More preferably, it is contained in the coalescence (core component).

The sheath component constituting the core-sheath type composite fiber of the present invention is required to prevent separation from the block copolymer. Further, when forming a cushion or the like, a thermoplastic polymer having a melting point of 200 ° C. or less, which is easy to melt, is preferable in order to enhance the adhesiveness with other fiber-forming thermoplastic polymers.

[0015]

Examples include polyethylene terephthalate and polybutylene terephthalate, which use a polyester polymer containing isophthalic acid as an acid component, and ethylene terephthalate polyester is preferable. It is generally known that when polyethylene terephthalate is copolymerized with isophthalic acid as a third component, the melting point and melt viscosity are lowered.

Isophthalic acid must be contained in the acid component of the polyester polymer in an amount of 20 to 50 mol%, preferably 25 to 45 mol%. When it is less than 20 mol%, the melting point and melt viscosity are less likely to be reduced, peeling from the core component is likely to occur, and when forming a cushion or the like, the adhesiveness to other fiber-forming thermoplastic polymer is poor. Become. When it is 50 mol% or more, the melt viscosity is excessively lowered and the yarn is inclined during melt spinning, which makes fiber formation difficult.

The polyester polymer of the sheath component may optionally contain a small amount of one or more other dicarboxylic acid components, oxycarboxylic acid components, and other diol components as copolymerized units. Good. In that case, other dicarboxylic acid components include aromatic dicarboxylic acids such as diphenyldicarboxylic acid and naphthalenedicarboxylic acid, or their ester-forming derivatives; dimethyl 5-sodium sulfoisophthalate, bis 5-sodium sulfoisophthalate (2 -Hydroxyethyl) and other metal sulfonate group-containing aromatic carboxylic acid derivatives; and aliphatic dicarboxylic acids such as oxalic acid, adipic acid, sebacic acid and dodecanedioic acid, or ester-forming derivatives thereof. In addition, examples of the oxycarboxylic acid component include p-oxybenzoic acid, p-β-oxyethoxybenzoic acid, and their ester-forming derivatives. As the diol component, diethylene glycol, 1,
Aliphatic diols such as 3-propanediol, 1,6-hexanediol and neopentyl glycol; 1,4-
Examples thereof include bis (β-oxyethoxy) benzene, polyethylene glycol and polybutylene glycol.

The weight ratio (core / sheath) of the core component and the sheath component in the core-sheath type composite fiber of the present invention is 80/20 to 20.
/ 80 is preferable, and the block copolymer is 80
If it exceeds the weight%, the processability of spinning, drawing and the like is significantly deteriorated. On the other hand, if the amount of the polymer is less than 20% by weight, elastic performance and vibration damping performance cannot be sufficiently obtained. In addition, the cooling may be insufficient and the spun raw yarn may stick. Therefore, it is desirable that the weight ratio of these is 70/30 to 40/60.

The conjugate fiber of the present invention can be spun by using an ordinary melt-spinning apparatus for core-sheath type conjugate fiber. However, in the vicinity of the spinning temperature condition, for example, at 280 ° C. It is important to use a combination of both components or a combination of spinning temperatures such that the melt viscosity is 280 poise or more higher than the melt viscosity of the thermoplastic polymer of the sheath component. When there is almost no difference in melt viscosity or when the magnitude relationship is reversed, the fibers stick together during spinning and winding, which is not preferable. Further, it is preferable that the difference in melt viscosity is large. However, if the difference is too large, kneeing during spinning becomes intense and stable spinning becomes difficult. Therefore, it is preferable to suppress the difference in melt viscosity to 1500 poises or less. .

The core-sheath form may be single-core or multi-core. In addition, the cross-sectional shape of the fiber may be circular, elliptical, dog-bone, tri-octagonal, multi-lobal, T-shaped, or any other modified cross-section, and the single yarn denier is not particularly limited and may be selected according to the intended product. Good enough, generally about 1
~ 50 denier, preferably about 1.5-30 denier.

If desired, various additives may be added to the conjugate fiber of the present invention. For example, catalyst, anti-coloring agent, heat-resistant agent, flame retardant, antibacterial agent, deodorant, optical brightener, matting agent, colorant, gloss improver, antistatic agent, aromatic agent,
Inorganic fine particles may be included.

[0023]

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited thereto. In the following examples, the peel strength, hardness, and repeated compression strain of the cushion material obtained by using the core-sheath type composite fiber were measured as follows. In the examples, the number average molecular weight was determined by the GPC method, and the microcoupling was measured by an NMR spectrum to obtain 4.8 ppm and 5.8 pp.
The content ratio of 3,4 bonds and 1,2 bonds was calculated from the ratio of the peaks of 3,4 bonds and 1,2 bonds of m and the peak of 1,4 bonds of 5.3 ppm, and the peak temperature of tan δ was It was determined by measuring the viscoelastic spectrum with Rheovibron (Oriental).

[Measurement of Peeling Strength of Cushion Material] (1) 30 parts by weight of the core-sheath type composite fiber for binder (fiber length 51 mm) produced in each of the following examples and hollow polyester fiber (6 denier; fiber length 64 mm) ) 70 parts by weight were mixed, and a web having a thickness of 20 mm was produced by using a card by a conventional method. From this web, length x width = 100 mm
A piece of × 100 mm is cut out, 10 pieces of the piece are stacked and placed in a flat plate mold, pressure 0.5 kg / cm ² , temperature 1
The cushion material was manufactured by heat treatment at 90 ° C. for 10 minutes. (2) For the cushion material obtained in (1) above, an Instron type universal testing machine (“Autograph D” manufactured by Shimadzu Corporation)
"CS type" to use JASO-M
The peel strength was measured according to 304.

[Measurement of Hardness of Cushion Material] Above (1)
In the same manner as above, a cushion material is used to obtain a hysteresis curve (strain amount-load curve) by an Instron type universal testing machine ("Autograph DCS type" manufactured by Shimadzu Corporation), and when the strain amounts are 25% and 50%. The hardness of the cushion material was determined by the load required for compression. The hardness value of the cushion material means a repulsive force (hardness) when the cushion material is depressed by compression, and is a value according to JIS-K6401.

[Measurement of Repeated Compressive Strain of Cushion Material] A cushion material was manufactured in the same manner as in the above (1), and the obtained cushion material had the original thickness (thickness before the compression test). And a device capable of compression that repeats the range of 50% thickness ("DF-10" manufactured by Kobunshi Keiki Co., Ltd.)
Was used to measure the thickness after 80,000 repeated compressions, and the ratio of the thickness to the original thickness (thickness before compression test) was expressed as a percentage. The value of compressive strain obtained by this method is a value according to JIS-K6401.

Examples 1 to 6 and Comparative Examples 1 to 6 As block copolymers, the content of styrene block A was 30% by weight, the content of 1,4 bonds in isoprene block was 95%, and the hydrogenation rate was 98%. Consists of block B,
A core component was prepared by using an ABA triblock type polymer having a number average molecular weight of 155,000 and a melt viscosity at 285 ° C. of 1500 poise. On the other hand, [η] containing 45 mol% of isophthalic acid as an acid component and 9 mol% of diethylene glycol as a diol component was 0.67.
Copolymerized polyethylene terephthalate of dl / g was used as a sheath component, and a conventional composite melt spinning device was used to form a concentric circular shape with a composite ratio of 50/50 at a circular cross-section spinneret hole of 285 ° C., and a discharge amount of 600 g / min and 1000 m / min. It was wound at a speed to obtain an undrawn yarn. The unstretched yarn was bundled, stretched at a draw ratio of 3 times, stretched at a stretching temperature of 65 ° C., mechanically crimped by an indentation type crimping device, and then cut into 51 mm to obtain a short fiber having a denier of 2 denier. (Example 1).

When the weight ratio of the block A and the block B in the core component was changed, when the content of isophthalic acid in the sheath component was changed, and when the weight ratio of the core component and the sheath component was changed. Physical properties of the core-sheath composite fibers produced in the same manner as in Example 1 and using the various binder fibers obtained as cushion materials: Examples 1 to 6 and Comparative Examples 1 to 6 are shown in Table 1. . However, Comparative Examples 4 to 6 are not shown in Table 1 for the following reason. Comparative Example 4 No data is available for the sheath component ratio (55/45) because the yarn is oblique during melt spinning and it is difficult to form a fiber. Comparative Example 5 The core-sheath weight ratio (85/15) is not available because it is difficult to wind the yarn during melt spinning. Comparative Example 6 The core-sheath weight ratio (15/85) is not available because it is difficult to wind the yarn during melt spinning.

[0029]

[Table 1]

[0030]

[0031]

[0032]

Examples 7 to 11 As a block copolymer, a block B having a styrene block A content of 30% by weight, an isoprene block content of 1,4 bonds of 70%, and a hydrogenation ratio of 98% is prepared.
A core component was prepared by using an ABA triblock type polymer having a number average molecular weight of 155,000 and a melt viscosity at 285 ° C. of 1300 poise. On the other hand, [η] containing 45 mol% of isophthalic acid as an acid component and 9 mol% of diethylene glycol as a diol component was 0.67.
Using polyethylene terephthalate of dl / g as a sheath component, a conventional composite melt spinning apparatus was used to form a concentric circle with a composite ratio of 50/50 from a round cross section spinneret hole at 285 ° C.
An undrawn yarn was obtained by winding at a discharge rate of 0 g / min and a speed of 1000 m / min. After this unstretched yarn was bundled, it was stretched at a draw ratio of 3 times and at a stretching temperature of 65 ° C., mechanical crimps were applied by a press-type crimping device, and then cut into 51 mm to obtain short fibers having a single denier of 2 denier. It was

In the following, the weight ratio of the block A and the block B in the core component is constant (30/70), the weight ratio of the core component and the sheath component is constant (50/50), and the hydrogenation rate is 98%. , Physical properties when a core-sheath type composite fiber was produced by changing the 1,4 bond content of the block B, and the obtained binder fiber was used as a cushioning material; Examples 1, 7 to 11
Is shown in Table 2.

[0035]

[Table 2]

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-2220 (JP, A) JP-A-5-51823 (JP, A) JP-A-5-230716 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) D01F 8/00-8/18

Claims (3)

(57) [Claims] 1. In a composite fiber in which two kinds of thermoplastic polymers are arranged in a core-sheath type over the entire length of the fiber, the thermoplastic polymer constituting the core component is a conjugated diene polymer block B.
And the aromatic vinyl polymer block A, wherein the thermoplastic polymer constituting the sheath component is a block copolymer.
The point is 200 ° C. or lower, and 20 to 50 mol in the acid component
Is a polyester polymer containing 100% of isophthalic acid.
Ri, composite ratio of the core component and the sheath component (core / sheath) of 20/80
A core-sheath type composite fiber for a binder, characterized in that it is 80/20. 2. The thermoplastic polymer constituting the core component, wherein the conjugated diene polymer block B is made of isoprene or isoprene-butadiene mixture, and the 1,4 bond content is 70% or more. A core-sheath type composite fiber for a binder as described above. 3. Among the thermoplastic polymers constituting the core component, the conjugated diene polymer block B is made of isoprene or isoprene-butadiene mixture, and the content of 3,4 bonds and 1,2 bonds is 40% or more. The core-sheath type composite fiber for a binder according to claim 1.