JP4457839B2 - Heat-fusible fiber - Google Patents

Description

  The present invention relates to a heat-fusible fiber and a cushion material using the same. More specifically, the present invention relates to a heat-fusible fiber and a cushioning material that are suitably used for a cushioning material having heat resistance particularly for applications that are exposed to a relatively high temperature environment such as for vehicles. Is.

  Synthetic fibers, especially polyester fibers, are indispensable in applications such as clothing and industrial materials from the standpoint of their excellent dimensional stability, weather resistance, mechanical properties and durability, and recyclability. Widely used in the field of non-woven fabrics. In a nonwoven fabric fiber structure used as a fiber cushion material used for roofing base materials, automobile ceiling materials, cushioning materials, etc., the purpose of bonding the constituent fibers of the nonwoven fabric fiber structure (hereinafter referred to as base material fibers) to each other Thermally adhesive fibers are widely used.

  As the base material fiber of the fiber cushion material, a relatively inexpensive and excellent polyester fiber is often used, and the heat-fusible fiber that bonds the base material fiber is also made of a polyester-based material because of its ease of recycling. Many things are used. For example, a core-sheath type polyester-based heat-sealing made of polyethylene terephthalate (hereinafter referred to as PET) whose core component is a low melting point copolymerized PET obtained by copolymerizing an isophthalic acid (hereinafter referred to as IPA) component. For the cohesive fiber, the copolymerization rate of the IPA component in the low-melting copolymerized PET is designed in accordance with the temperature at which the heat-fusible fiber is bonded.

  In general, when the copolymerization ratio of IPA increases with respect to PET, the melting temperature measured by a differential scanning calorimeter (hereinafter referred to as DSC) of the copolymerized PET decreases. In this case, the melting temperature means a temperature corresponding to an endothermic peak measured by DSC. For example, when the melting temperature of homo-PET containing no copolymer component is measured by DSC, an endothermic peak is confirmed in the range of 250 to 260 ° C., but the endothermic peak is lowered to about 210 ° C. in IPA 20 mol% copolymerized PET. At the same time, the range in which the endothermic peak is observed tends to widen. Further, in IPA 40 mol% copolymerized PET, the melting temperature is lowered to about 110 ° C., but the melting temperature range becomes too wide, the endothermic amount at the melting temperature is lowered, and the melting peak cannot be observed. In this case, since the melting temperature cannot be measured by DSC, the melting temperature is measured with a melting point microscope or the like.

  On the other hand, for example, when heat-treating a cushion material made of polyester fiber as a base material fiber together with the heat-fusible fiber, the heat treatment is usually performed at a heat bonding temperature of 220 ° C. or less in consideration of the heat resistance of the base material fiber. In order to cope with such a thermal bonding temperature, a method is used in which the melting temperature is reduced to about 110 ° C. by using IPA 40 mol% copolymerized PET as a thermal fusion component (Patent Document 1, (See Patent Document 2 and Patent Document 3). However, when 40 mol% of IPA is copolymerized, the melting temperature is lowered, but the melting temperature is also widened, the melting start temperature is greatly lowered, and melting starts gradually from around 70 ° C. As described above, the polyester heat-fusible fiber can be bonded at a practical bonding temperature, and generally, copolymerized PET obtained by copolymerizing 30 to 50 mol% of IPA is widely used. However, since the melting start temperature of the copolymerized PET, which is the heat-sealing component, is also lowered to 70 to 80 ° C., when the heat-bonded cushion material is exposed to an environment of 90 to 100 ° C., one of the adhesion points. The part is remelted, the bonding point is removed, and the cushion material is deformed. Therefore, for example, in applications that are exposed to an environment of 90 to 100 ° C., such as automotive ceiling materials, the polyester heat-fusible fiber made of IPA copolymerized PET is used in terms of the heat resistance of the cushioning material. could not.

Special copolyesters have been proposed to improve the heat resistance of the above problems, but all of them require special components to be used as copolymerization components, which require raw material costs and complicated production processes for polymers. There exists a problem that cost becomes high (refer patent document 4 and patent document 5).
JP 58-41912 A Japanese Patent Laid-Open No. 2-139466 JP-A-6-280147 JP 7-1119011 A JP 2000-160430 A

  An object of the present invention is to provide a heat-fusible fiber suitably used for a heat-resistant cushioning material that could not be achieved by the above-described prior art and a cushioning material using the heat-fusible fiber. is there.

In order to solve the above problems, the present invention has the following configuration.
That is, the heat-fusible fiber of the present invention is a composite fiber composed of a plurality of polymer components, and at least a part of the polymer component exposed on the fiber surface is terephthalic acid and / or of all acid components. A polybutylene terephthalate copolymer polyester, the derivative of which is composed of 75 to 60 mol%, the other aromatic dicarboxylic acid component is composed of 5 mol% or more, the glycol component is composed only of butylene glycol, and the melting temperature is 140 to 190 ° C. It is a heat-fusible fiber characterized by comprising only .
One of the preferred embodiments is that the fiber is a core-sheath type composite fiber, and the sheath component consists only of the polybutylene terephthalate copolymer polyester.

Moreover, the heat-fusible fiber of the present invention is composed of 75 to 60 mol% of terephthalic acid and / or its derivative, and 5 mol% or more of other aromatic dicarboxylic acid components among all acid components, and a glycol component. Is a heat-fusible fiber characterized by comprising only polybutylene terephthalate copolymer polyester having only a butylene glycol and a melting temperature of 140 to 190 ° C.

The heat-sealing fiber is preferably a short fiber having a fiber length of 3 to 100 mm.

Further, the cushion material of the present invention is a cushion material for the matrix fibers are bonded by heat fusion fiber according to the the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the heat | fever adhesive fiber applied to the use with many opportunities exposed to comparatively high temperature environments, such as an object for vehicles, especially the cushioning material and solid cotton etc. which have the outstanding heat resistance is obtained. In addition, according to the present invention, a heat-adhesive fiber can be applied to a base material fiber to obtain a cushioning material, solid cotton, or the like that is resistant to peeling off of the contact point of the base material fiber and has excellent heat resistance.

  Hereinafter, the heat-fusible fiber of the present invention will be described in detail.

Thermally fusible fibers of the present invention, heat at least partially heat-fusible polymer component which is exposed to the fiber surface, the melting temperature is only port polybutylene terephthalate-based copolyester of 140 to 190 ° C. Adhesive composite fiber or single fiber. In the present invention, the melting temperature refers to a temperature corresponding to an endothermic peak in a melting curve measured by DSC. In the melting curve measured by DSC, the endothermic peak that cannot be confirmed refers to the temperature measured with a melting point microscope.

Used in the present invention, positive polybutylene terephthalate-based copolyester melting temperature 140 to 190 ° C. is mainly serving constituents, a repeating unit of butylene terephthalate. Generally, since the melting temperature of unmodified (copolymerized) polybutylene terephthalate (hereinafter referred to as PBT) is 230 to 235 ° C., the polybutylene terephthalate having a melting temperature of 140 to 190 ° C. used in the present invention is used. Must lower the melting temperature. The melting temperature of PBT can be lowered by copolymerizing the third component as in the case of PET.
Lupo polybutylene terephthalate-based copolyester put the present invention, terephthalic acid and / or derivatives thereof from 75 to 60 mol% of the total acid components, copolymerized other aromatic dicarboxylic acid component not less than 5 mol% It is necessary to become. By copolymerizing an aromatic dicarboxylic acid component other than the terephthalic acid component, the melting temperature is lowered and the glass transition temperature is also lowered. As the glass transition temperature is lowered, the polymer exhibits soft properties. In the present invention, by using other aromatic dicarboxylic acid component as a copolymerization component in an amount of 5 mol% or more, by suppressing the lowering of the glass transition point, the contact at the time of fusion becomes hard, and the contact at high temperature It works to prevent softening due to remelting. Other aromatic dicarboxylic acid components need to be copolymerized in an amount of 5 mol% or more. Particularly, when used for applications such as cotton wool that requires rigidity, among all the acid components, terephthalic acid and / or Or you may use another aromatic dicarboxylic acid component for all the copolymerization components except the derivative (s). That is, terephthalic acid and / or a derivative thereof can be used in an amount of 75 to 60 mol%, and other aromatic dicarboxylic acid components can be used in an amount of 25 to 40 mol%.

  Examples of terephthalic acid derivatives include dimethyl terephthalate, diethyl terephthalate, and methyl ethyl terephthalate.

  As other aromatic dicarboxylic acid components, isophthalic acid (hereinafter referred to as IPA), phthalic acid, and the like can be used, but considering the production cost and the heat resistance of the polymer, IPA may be used as a copolymerization component. preferable.

Further, the glycol component for constituting a reportage polybutylene terephthalate-based copolyester used in the present invention is butylene glycol.

As other copolymer components, bifunctional carboxylic acids such as adipic acid and sebacic acid may be used as long as the performance of the present invention is not impaired.

The heat-fusible fiber according to the present invention is composed of 75 to 60 mol% of terephthalic acid and / or its derivative among all acid components, and 5 mol% or more of other aromatic dicarboxylic acid components, and a glycol component only butylene glycol, polybutylene terephthalate-based copolyester melting temperature is 140 to 190 ° C., either alone melt spinning, or to other polymers and a double combined and melt spinning, stretching, requires It can be manufactured by cutting to a predetermined length according to.

Heat fusible fibers used in the present invention, it is important that heat sealing polymer component consisting of only the above port polybutylene terephthalate-based copolyester is exposed to at least a portion the fiber surface. To expose the terms of strength properties of the cushion material on the fiber surface, alone or melt spinning and multi combined and melt-spinning with other polymers. As one of suitable forms, concentric or eccentric core-sheath type, side-by-side type, sea-island type, etc. can be used. When the concentric core-sheath type is used, the yarn forming property is good, and when the eccentric type is used, the latent crimping property is obtained. Therefore, an appropriate composite form can be selected according to the application.

When a sheath-core form, in terms of the strength properties of the cushion material, using only port polybutylene terephthalate-based copolyester as the heat fusing polymer component as the sheath component, the melting temperature in the core component 220 It is preferable to use other polymers such as polyester having a temperature of at least ° C. As the polyester of the core component, polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate are preferably used. Further, from the viewpoint of resource reuse and environmental protection, recycled polyester can be used as the core component. Furthermore, the core component may be a mixture of two or more types of polymers as long as the effects of the present invention are not impaired, and the core component may be in a bimetallic composite form. Moreover, you may add additives, such as matting materials, such as titanium dioxide, and a lubricant, to a core component. The composite ratio of the core-sheath is preferably 20/80 to 80/20 from the viewpoint of yarn production, and the composite ratio of the core-sheath is more preferably 40/60 to 60/20 from the viewpoint of adhesion and high-order processability. 40.

  The cross-sectional shape of the heat-bondable fiber of the present invention may be circular or irregular. The heat-bondable fiber of the present invention may be used without being stretched after spinning, or may be used after being stretched, or may be crimped as desired. Moreover, although the heat bondable fiber of this invention can be used with a long fiber, it can be cut | disconnected to desired fiber length and can be used as a short fiber.

  The fiber length is preferably in the range of 3 mm to 100 mm. When the fiber length is less than 3 mm, the ratio of cross-linking with the base cotton is reduced, and the rigidity as the structure is inferior. On the other hand, if the fiber length exceeds 100 mm, the carding property and the like are deteriorated, resulting in problems in product processing. The fiber length is preferably in the range of 20 to 70 mm from the viewpoint of improving the carding property at the time of product processing and the formation of the nonwoven fabric.

  In view of the influence of the number of contact points of the base fiber on the strength characteristics when the heat-adhesive fiber of the present invention is used as a cushioning material, the single-fiber fineness of the heat-adhesive fiber is preferably 50 dtex or less and serves as a base. In consideration of the blendability with the base material fibers and higher processability, it is more preferably 10 dtex or less.

  On the other hand, if the single fiber fineness is in the range of 0.5 d or less, the contact itself after melting becomes small, so that the target rigidity becomes inferior, which is not preferable. The single fiber fineness is preferably 2 dtex or more from the viewpoint of obtaining sufficient rigidity of the contact.

  The cushion material according to the present invention is formed by bonding base material fibers with the above-described heat-bondable fibers of the present invention. The weight ratio of the heat-bondable fibers contained in the cushion material can be selected depending on the use, and is used in combination with the heat-bonded fibers other than the heat-bonded fibers of the present invention as long as the effects of the present invention are not impaired. May be.

  The cushion material of the present invention is obtained by blending the short fibers made of the heat-adhesive fibers of the present invention with short fibers (base material fibers) such as ordinary polyester fibers and applying them to a card machine or an air lay apparatus to form a non-woven web. If necessary, it can be obtained by performing needle punching or hydroentanglement and then heat-treating at a predetermined temperature to melt and bond the heat-fusible fiber.

  The heat treatment temperature is preferably about a melting temperature of about 10 to 30 ° C. from the viewpoint of improving the crystallinity of the adhesive component after cooling and solidification, that is, maintaining a contact in a high temperature atmosphere.

  The base fiber used in the cushion material of the present invention is preferably a polyester fiber in terms of cost and recyclability. Although the base material fiber differs depending on the application, generally, for example, if a cushion material or bulkiness is required, a polyester fiber of 6 to 30 dtex is used, or a soft texture is required. If so, polyester fibers of 1 to 6 dtex are used as the base material fibers. In addition, recycled polyester fibers may be used as the base material fibers from the viewpoint of resource reuse and environmental protection. Further, two or more kinds of base material fibers may be used. These base material fibers are preferably mixed in a range of 20/80 to 80/20% by weight of a base material fiber / thermoadhesive fiber from the balance between the rigidity of the base material and the degree of adhesion.

  Hereinafter, the details of the heat-bondable fiber of the present invention will be described using examples. Each characteristic value defined in the present invention is obtained by the following method.

(1) Melting temperature A differential scanning calorimeter (DSC) was measured at a heating rate of 10 ° C./min under a nitrogen stream.
B. When the melting temperature could not be confirmed by the above DSC, the melting start temperature and the melting completion temperature were observed at a heating rate of 10 ° C./min using a melting point microscope, and the melting temperature was determined by the following equation.
Melting temperature (° C.) = (Melting start temperature + melting completion temperature) / 2
(2) Evaluation of heat-resistant stickiness From a cushion material prepared under appropriate conditions, a region of 20 mm from one end in the longitudinal direction (130 mm) of a sample obtained by cutting into a shape of 130 mm × 25 mm × 10 mm is fixed on a table, The remaining 110 mm was protruded from the table. Next, while maintaining this state, the sample was left in a thermostatic bath set at a temperature of 90 ° C. for 8 hours, and the amount of sag (mm) at the tip of the portion protruding from the base of the rectangular parallelepiped was measured. The determination is as follows. Those with a sag of 12 mm or less can be evaluated as having excellent heat resistance.
◎; Very good (sag amount 9mm or less)
○: Good (The amount of sag is larger than 9mm and 12mm or less)
X: Poor (sagging amount is larger than 12 mm).

(3) Single fiber fineness The single fiber fineness was measured by the method shown in JIS L-1015 (1999) -8-5-1.

(4) Intrinsic viscosity It calculated from the solution viscosity measured at 25 degreeC in the o-chlorophenol solution.

Example 1
The intrinsic viscosity [η] obtained by transesterification using 65 mol% of dimethyl terephthalate and 35 mol% of isophthalic acid as the acid component, 100 mol% of butylene glycol as the glycol component, and then polycondensation reaction is 0.62. A copolyester (A component, melting point 160 ° C.) and a separately prepared polyethylene terephthalate (PET, B component) having an intrinsic viscosity [η] of 0.64 and a melting point of 260 ° C. at a spinning temperature of 280 ° C. Core-sheath-type composite unstretched with a core-sheath composite ratio of 50:50, wherein the core component is composed of the B component and the sheath component is composed of the A component. I got a thread.

  Subsequently, the obtained core-sheath composite undrawn yarn was drawn three times in warm water at a temperature of 80 ° C. to obtain a 4.4 dtex drawn yarn, and the oil agent (anionic surfactant) was used as the active ingredient of the oil agent. After applying so as to adhere a ratio of 0.15 wt%, crimping (crimp number: 10 ridges / 25 mm) was applied, and then cut to a fiber length of 38 mm to obtain a heat-fusible fiber having a short fiber shape.

The obtained heat-fusible fiber 70% by weight and a fiber length of 38 mm and a polyethylene terephthalate fiber with a fineness of 14.4 dtex, 30% by weight, obtained by separately opening with a spreader, are mixed, and the thickness is 30 mm with a card machine. A web having a basis weight of 800 g / m ² was formed. The web was sandwiched between iron plates with a surface temperature of 180 ° C., compressed to a thickness of 10 mm, and heat treated at 180 ° C. for 2 minutes in a hot air dryer to obtain a nonwoven fabric. . Next, the obtained non-woven fabric was sandwiched between iron plates having a surface temperature of 220 ° C., compressed to a thickness of 10 mm, and heat-treated at a temperature of 220 ° C. for 3 minutes in a hot air dryer to obtain a cushion material. Table 1 shows the heat resistance of the obtained cushion material. The heat resistance was very good at 7 mm.

(Example 2)
A copolyester (component A, melting point 160 ° C.) having an intrinsic viscosity [η] of 0.62 was obtained by the same production method as in Example 1. Using this copolymer polyester, it was discharged from a spinneret at a spinning temperature of 280 ° C., and melt-spun at a take-up speed of 1500 m / min to obtain an undrawn yarn.

  Next, the obtained undrawn yarn was drawn 3 times in warm water at a temperature of 80 ° C. to obtain a 4.4 dtex drawn yarn, and the oil agent (anionic surfactant) was used as the oil agent active ingredient with a fiber weight ratio of 0.15 wt. %, And then crimped (crimp number: 10 peaks / 25 mm), and then cut into a fiber length of 38 mm to obtain a heat-fusible fiber having a short fiber shape.

70% by weight of the heat-fusible fiber obtained was mixed with 30% by weight of a polyethylene terephthalate fiber having a fiber length of 38 mm and a fineness of 14.4 dtex obtained by opening with a separate opening machine, and the web was laminated with a card machine. , A web having a thickness of 30 mm and a basis weight of 800 g / m ² is formed. The web is sandwiched between iron plates having a surface temperature of 180 ° C., compressed to a thickness of 10 mm, and heated in a hot air dryer at a temperature of 180 ° C. for 2 minutes. A non-woven fabric was obtained by heat treatment. Next, the obtained non-woven fabric was sandwiched between iron plates having a surface temperature of 220 ° C., compressed to a thickness of 10 mm, and heat-treated at a temperature of 220 ° C. for 3 minutes in a hot air dryer to obtain a cushion material. Table 1 shows the heat resistance of the obtained cushion material. The heat resistance was as very good as 9 mm.

(Example 3)
Copolyester having 65 mol% dimethyl terephthalate and 35 mol% phthalic acid as the acid component, transesterification using 100 mol% of butylene glycol as the glycol component, followed by polycondensation reaction and an intrinsic viscosity [η] of 0.65 (Melting point 160 ° C.) was obtained. A core-sheath composite fiber was obtained in the same manner as in Example 1 except that the obtained copolymer polyester was used as the component A, and then a cushion material was obtained in the same manner as in Example 1. Table 1 shows the heat resistance of the obtained cushion material. The heat resistance was as good as 10 mm.

(Comparative Example 1)
Copolyester having an intrinsic viscosity [η] of 0.66 by transesterification using 100 mol% of dimethyl terephthalate as the acid component and 33 mol% of butylene glycol and 67 mol% of ethylene glycol as the glycol component, followed by polycondensation reaction (Melting point 178 ° C.). A core-sheath type composite fiber was obtained in the same manner as in Example 1 except that the obtained copolyester was used instead of the component A, and then a cushion material was obtained in the same manner as in Example 1. Table 1 shows the heat resistance of the obtained cushion material. The heat resistance was inferior in heat resistance with a large amount of sag of 15 mm.

(Comparative Example 2)
A copolyester having an intrinsic viscosity [η] of 0.60 by transesterification using 60 mol% of dimethyl terephthalate and 40 mol% of isophthalic acid as the acid component and 100 mol% of ethylene glycol as the glycol component, followed by a polycondensation reaction. Melting point 110 ° C.). A core-sheath type composite fiber was obtained in the same manner as in Example 1 except that the obtained copolyester was used instead of the component A, and then a cushion material was obtained in the same manner as in Example 1. Table 1 shows the heat resistance of the obtained cushion material. The heat resistance was 27 mm and the amount of drooping was very large, and the heat resistance was inferior.

(Comparative Example 3)
Copolyester having 60 mol% dimethyl terephthalate and 40 mol% isophthalic acid as the acid component, transesterification reaction using 100 mol% ethylene glycol as the glycol component, and then polycondensation reaction and having an intrinsic viscosity [η] of 0.60 (Melting point 110 ° C.) was obtained. A fiber was obtained in the same manner as in Example 2 except that the obtained copolyester was used instead of the component A, and then a cushion material was obtained in the same manner as in Example 1. Table 1 shows the heat resistance of the obtained cushion material. The heat resistance was 30 mm and the amount of drooping was very large, and the heat resistance was inferior.

  According to the present invention, a heat-adhesive fiber capable of obtaining a cushioning material or solid cotton having excellent heat resistance and a cushioning material or solid cotton using the same can be obtained, which is industrially useful.

Claims (5)

A composite fiber comprising a plurality of polymeric components, polymeric components, at least a part is exposed on the fiber surface, of the total acid components, terephthalic acid and / or derivatives thereof from 75 to 60 mol%, other aromatic Heat fusion, characterized in that the aliphatic dicarboxylic acid component is composed of 5 mol% or more, the glycol component is composed only of butylene glycol , and is composed only of a polybutylene terephthalate copolymer polyester having a melting temperature of 140 to 190 ° C. fiber. Fibers are core-sheath type composite fibers, heat-fusible fibers according to claim 1, wherein the sheath component is composed of only the polybutylene terephthalate-based copolyester. Among all the acid components, terephthalic acid and / or its derivative is composed of 75 to 60 mol%, the other aromatic dicarboxylic acid component is composed of 5 mol% or more, the glycol component consists of butylene glycol only, and the melting temperature is 140 to A heat-fusible fiber comprising only a polybutylene terephthalate copolymer polyester at 190 ° C. The heat-fusible fiber according to any one of claims 1 to 3, wherein the fiber is a short fiber having a fiber length of 3 to 100 mm. Matrix fibers, cushioning material, characterized in that it is bonded by heat fusion fiber according to any one of claims 1 to 4.