JP2001123334A - Heat bonding fiber and fiber sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a bonding fiber bondable so as to have low repulsion and excellent deformation and a fiber sheet using the bonding fiber. SOLUTION: The heat bonding fiber is a fiber provided with a polyester-based resin comprising a tertiary carbon and/or quaternary carbon-containing diol component. The fiber sheet is bonded by the heat bonding fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat-adhesive fiber and a fiber sheet using the heat-adhesive fiber. in particular,
A heat-adhesive fiber that can be suitably used as a fiber constituting a fiber sheet that can be used to reinforce plastic, concrete, and the like, and reinforcing plastic, concrete, and the like using the heat-adhesive fiber The present invention relates to a fiber sheet that can be suitably used for the above.

[0002]

2. Description of the Related Art For example, plastic alone has low strength and must be thickened to increase strength. Therefore, plastic alone cannot satisfy both strength performance and weight reduction. Therefore, a composite material (a so-called fiber reinforced plastic, FRP) in which a plastic is reinforced with a nonwoven fabric made of high-strength glass fiber, carbon fiber, boron fiber or the like is used.
As the non-woven fabric for reinforcement, the applicant of the present application has reported that the fiber length is 2
A staple fiber group having an opened fiber of 5 to 150 mm and an unopened staple fiber group in which a plurality of fibers are present in a converged state are mixed, and non-glass-based reinforcing fibers are bonded with adhesive fibers between fibers. Sheet material ”(JP-A-63-42952)
No.). This reinforcing nonwoven fabric has an excellent reinforcing effect, but when it has a complicated shape, it may not be possible to reinforce it in a desired shape. For example, when the veranda is covered with a fiber-reinforced plastic, the reinforcing non-woven fabric is laid and then impregnated with an unsaturated polyester resin containing a styrene monomer, for example. In some parts (boundary between the floor surface and the wall surface), the nonwoven fabric for reinforcement did not fit into the corners and sometimes jumped up. Since the plastic cannot be reinforced if the nonwoven fabric for reinforcement jumps up in this way, it has been necessary to impregnate the unsaturated polyester resin repeatedly over and over again, resulting in a reduction in workability.

[0003]

As a result of pursuing the above-mentioned phenomena, the present inventors have found that there is a problem with the adhesive fibers used in the reinforcing nonwoven fabric, and have reached the present invention. An object of the present invention is to provide an adhesive fiber which does not cause the above-described problems, and to provide a fiber sheet using the adhesive fiber.

[0004]

The heat-adhesive fiber of the present invention is a fiber provided with a polyester resin containing a diol component containing tertiary carbon and / or quaternary carbon. The present inventors have found that a fiber sheet bonded with such a thermo-adhesive fiber comprising a polyester resin has low resilience and excellent deformability.

[0005] Since the fiber sheet of the present invention is bonded by the above-mentioned heat-adhesive fiber, it has low resilience and excellent deformability. This fiber sheet can be suitably used especially as a molding base for fiber reinforced plastic.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a polyester resin containing a diol component containing tertiary carbon and / or quaternary carbon (hereinafter referred to as "essential diol component") as a heat-adhesive fiber. It has been found that not only the heat bonding property but also the fiber sheet bonded by the heat bonding fiber is excellent in the deformability. Even if this essential diol component is composed of a chain aliphatic compound, it may be composed of a cyclic aliphatic compound, but since it is composed of a chain aliphatic compound, it is more excellent in deformability. ,
It is a more preferred essential diol component. More specific essential diol components include, for example, 1,2-propanediol, neopentyl glycol, pinacol, 1,3
-Use a chain diol component such as butanediol or a cyclic diol component such as cyclopentane-1,2-diol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, or 1,4-cyclohexanediol. can do. Among these, it is preferable to contain a chain diol component, more preferably 1,2-propanediol and / or neopentyl glycol, and even more preferably 1,2-propanediol. . It is sufficient that at least one such essential diol component is contained. The molar ratio of this essential diol component to the whole diol component is 3
It is preferably at least 0 mol%. This molar ratio is 30
When the amount is less than mol%, the deformability of the fiber sheet thermally bonded with the heat-adhesive fiber of the present invention tends to be deteriorated. Therefore, it is more preferably 35% by mol or more, and further preferably 4% or more.
0 mol% or more, and most preferably 45 mol% or more. As the diol component other than the essential diol component (hereinafter, referred to as “addition diol component”), for example,
Ethylene glycol, trimethylene glycol, 1,4
-Butanediol, 1,5-pentanediol, 1,6
-Hexanediol, 1,7-heptanediol, 1,
8-octanediol, 1,9-nonanediol, 1,
One or more kinds of 10-decanediol and the like can be contained. Among them, it is preferable to contain ethylene glycol. The molar ratio of ethylene glycol to the whole diol component is preferably 70 mol% or less, more preferably 65 mol% or less, and 6 mol% or less.
It is more preferably at most 0 mol%, most preferably at most 55 mol%. Therefore, the diol component of the present invention comprises 1,2-propanediol and / or neopentyl glycol (particularly, 1,2-propanediol).
Is preferably 30 mol% or more and ethylene glycol 70 mol% or less, and 1,2-propanediol and / or neopentyl glycol (particularly,
More preferably, the composition is composed of 35 mol% or more of 1,2-propanediol) and 65 mol% or less of ethylene glycol. 1,2-propanediol and / or neopentyl glycol (particularly, 1,2-propanediol) Diol) and at least 40 mol% and ethylene glycol 60 mol%
More preferably, the composition is composed of 45 mol% or more of 1,2-propanediol and / or neopentyl glycol (particularly, 1,2-propane diol) and 55 mol% or less of ethylene glycol. Is most preferred.

On the other hand, the dibasic acids constituting the polyester resin include, for example, aromatic dibasic acids such as terephthalic acid, isophthalic acid, phthalic acid, p-oxybenzoic acid, 5-sodium sulfoisophthalic acid and naphthalenedicarboxylic acid. Acids, oxalic acid, adipic acid, sebacic acid, azelaic acid, aliphatic dibasic acids such as dodecanedicarboxylic acid, or one or more kinds of alicyclic dibasic acids such as 1,2-cyclobutanedicarboxylic acid can be contained. . Of these, isophthalic acid is preferred because it contains a fiber sheet bonded with thermo-adhesive fibers and has excellent deformability. The preferred molar ratio of the isophthalic acid component to the entire dibasic acid component is preferably at least 5 mol%, more preferably at least 10 mol%, and at least 15 mol%. More preferably, 2
Most preferably, it is contained in an amount of 0 mol% or more. Terephthalic acid is suitable as the dibasic acid component to be combined with the isophthalic acid component, and the molar ratio of the terephthalic acid component to the entire dibasic acid component is preferably 95 mol% or less, more preferably 90 mol%. More preferably, it is contained in an amount of at most 85 mol%, most preferably at most 80 mol%. Therefore, the dibasic acid component of the present invention preferably contains isophthalic acid of 5 mol% or more and terephthalic acid of 95 mol% or less, and preferably contains isophthalic acid of 10 mol% or more and terephthalic acid of 90 mol% or less. More preferred,
15% by mole or more of isophthalic acid and 85% by mole of terephthalic acid
More preferably, it is contained in isophthalic acid 20
Most preferably, it is contained in an amount of not less than 80 mol% and not more than 80 mol% of terephthalic acid.

[0008] Therefore, the polyester resin of the present invention contains, as a diol component, 1,2-propanediol and / or neopentyl glycol (particularly, 1,2-propanediol) at least 30 mol% and ethylene glycol at 70 mol%. Hereinafter, it is preferable to contain 5 mol% or more of isophthalic acid and 95 mol% or less of terephthalic acid as a dibasic acid component, and 1,2-propanediol and / or neopentyl glycol (particularly, 1,2
-Propanediol) More preferably contains 35 mol% or more, ethylene glycol 65 mol% or less, isophthalic acid 10 mol% or more and terephthalic acid 90 mol% or less as a dibasic acid component, and 1,2-propane as a diol component. Diol and / or neopentyl glycol (particularly, 1,2-propanediol) contains at least 40 mol%, at most 60 mol% of ethylene glycol, and at least 15 mol% of isophthalic acid and at most 85 mol% of terephthalic acid as a dibasic acid component. More preferably, the diol component is 1,2-propanediol and / or neopentyl glycol (particularly, 1,2-propanediol) in an amount of 45 mol% or more and ethylene glycol 55 mol% or less, and the dibasic acid component is isophthalic acid. Contains 20 mol% or more of acid and 80 mol% or less of terephthalic acid Most preferably, there. The polyester resin of the present invention may contain other components within a range satisfying the above-described composition conditions. The glass transition temperature of the polyester resin of the present invention is preferably 40 ° C. or higher, and is preferably 50 ° C. or higher so that the polyester resin does not adhere during storage or the like and is easy to handle during production and / or use. The temperature is more preferably 60 ° C. or more, and most preferably 70 ° C. or more. "Glass transition temperature" in the present invention is JIS K 7121.
^Refers to the value obtained from the method for determining the glass transition temperature specified in ^-1987 . The number average molecular weight of the polyester resin of the present invention is suitably about 15,000 to 25,000. The “number average molecular weight” refers to the number average molecular weight in terms of styrene measured by GPC (gel permeation chromatography). Furthermore, it has been found that if the polyester resin of the present invention is non-crystalline, that is, has no melting point, a fiber sheet having low resilience and excellent deformability can be produced. This “no melting point” means that a peak other than the glass transition temperature is found in a DSC curve obtained by a heat flux differential scanning calorimetry (DSC, heating temperature: 10 ° C./min) specified in JIS K ^7121-1987. Is not substantially shown.

The heat-bondable fiber of the present invention is provided with at least one kind of the above-mentioned polyester resin (hereinafter referred to as "essential polyester resin"). Good, it may contain a resin other than the essential polyester resin, but so as to maintain the strength of the heat-bondable fiber when thermally bonded, because the essential polyester resin tends to have poor spinnability, It is preferable to include one or more resins other than the essential polyester resin. As a resin other than the essential polyester-based resin, a melt-spinnable thermoplastic resin can be used. For example, a polyester-based resin containing a diol component containing no tertiary carbon and / or quaternary carbon (for example, Polyethylene terephthalate, polybutylene terephthalate, etc.), polyamide resin, polyolefin resin (for example, polyethylene resin, polypropylene resin, etc.), polyvinylidene chloride resin, polyvinyl chloride resin, polystyrene resin, polyacrylonitrile resin, Examples thereof include polyvinyl alcohol-based resins. Among these, a polyester resin or polypropylene containing a diol component not containing a tertiary carbon and / or a quaternary carbon can be preferably used. A polyester resin (particularly, polyethylene terephthalate or polybutylene terephthalate) containing a diol component containing no tertiary carbon and / or quaternary carbon, which is difficult to peel off from the resin, is preferable. When the thermoplastic resin is contained, the essential polyester-based resin is preferably present on the fiber surface so that the essential polyester-based resin easily acts as a heat-adhesive component. However, as long as the essential polyester resin can be exposed on the fiber surface by the action of heat, pressure, or the like, it does not necessarily need to be present on the fiber surface. Examples of the former fiber cross-sectional shape existing on the fiber surface include a core-sheath type (including eccentricity) sheath component, a side-by-side type component, a sea-island type sea component, an orange type component, One component of the multi-bimetal type may be mentioned, and examples of the fiber cross-sectional shape that does not exist on the fiber surface include a core-sheath type (including eccentric type) core component and a sea-island type island component. Can be mentioned. Among these, there are many essential polyester-based resins that can participate in adhesion, as a core-shell type (including eccentricity) sheath component or a sea-island type sea component,
Preferably, an essential polyester resin is present.
In the fiber cross section, the essential polyester resin and the thermoplastic resin are of a core-sheath type (including the case of eccentricity), a side-by-side type, a sea-island type, an orange type, or a multi-bimetal type in the fiber cross section. In the case of being compounded in the essential polyester resin, if a thermoplastic resin similar to the above-mentioned thermoplastic resin is further mixed, spinning properties and fiber properties can be further improved, so that it is preferable to use It is an aspect. For example, when an essential polyester resin and a thermoplastic resin are mixed as a sheath component of the core-sheath type thermoadhesive fiber, spinnability and fiber properties can be further improved. In this case, the thermoplastic resin constituting the core component and the thermoplastic resin mixed in the essential polyester resin may be the same or different. When the essential polyester-based resin and the thermoplastic resin are contained, the mass ratio is not particularly limited, but the thermal adhesion by the essential polyester-based resin, the form stability at the time of the thermal adhesion by the thermoplastic resin, and the spinning (Essential polyester resin) :( thermoplastic resin) =
The ratio is preferably 2: 8 to 8: 2, (essential polyester resin) :( thermoplastic resin) is more preferably 3: 7 to 7: 3, and (essential polyester resin) :( thermoplastic). (Resin) = 4: 6 to 6: 4 is more preferable. Further, the cross-sectional shape of the heat-adhesive fiber is not particularly limited, and may be non-circular (for example, elliptical,
Oval shape, T shape, Y shape, + shape, hollow shape, polygonal shape, etc.). Although the fineness of the heat-adhesive fiber of the present invention is not particularly limited, it is preferable to use 2.
It is preferably from 2 dtex (decitex) to 11 dtex. The heat-adhesive fiber may be a filament or a staple having a length of about 1 to 160 mm. In the essential polyester resin and / or the thermoplastic resin constituting the heat-adhesive fiber, for example, an antioxidant, a fluorescent whitening agent, an ultraviolet absorber, a moisture absorbent, a matting agent,
Pigments, flame retardants, stabilizers, antistatic agents, colorants, dyes,
Various functions may be added by mixing functional substances such as a conductive agent, a heat-resistant agent, a hydrophilic agent, a deodorant, and an antibacterial agent. Such a heat-adhesive fiber of the present invention can be spun by using an ordinary spinning apparatus. For example, 40 mol% or more of 1,2-propanediol and 60 mol% or less of ethylene glycol as a diol component, 20 mol% or more of isophthalic acid and 8% of terephthalic acid as a dibasic acid component.
The core-sheath type thermo-adhesive fiber having an essential polyester resin containing 0 mol% or less as a sheath component and polyethylene terephthalate as a core component is prepared by setting the spinning temperature to 280 to 300 ° C. by a conventional composite spinning apparatus. Can be spun. The unstretched yarn spun in this manner is 2-1 to 2 at a temperature near the glass transition temperature of the essential polyester resin.
The thermoadhesive fiber of the present invention can be manufactured by drawing 0 times. When this heat-adhesive fiber is used as a raw material of a dry nonwoven fabric or as a spun yarn, it is preferable to mechanically or thermally crimp about 5 to 50 pieces / inch.

[0010] Since the fiber sheet of the present invention is bonded by the above-mentioned heat-adhesive fiber, it has low resilience and excellent deformability. Examples of the fiber sheet include a woven fabric, a knitted fabric, a nonwoven fabric, and a composite thereof.
When this fiber sheet is used as a molding substrate for fiber-reinforced plastic, it is preferable that the fiber sheet is a nonwoven fabric capable of easily removing bubbles that are mixed in when impregnating the plastic. The mass ratio of the heat-adhesive fiber of the present invention in the fiber sheet is preferably 10% by mass or more, more preferably 20% by mass or more, and more preferably 30% by mass or more so that the heat adhesion is excellent. More preferably, it is included. When the heat-adhesive fiber of the present invention is used as a fiber sheet of a molding substrate for fiber-reinforced plastic, the heat-adhesive fiber should be heat-bonded without lowering the reinforcing effect of the high-strength fiber as described below. , 3-20 mass
%, More preferably 5 to 15 mass%. Normal fibers can be used as the fibers other than the heat-adhesive fibers, for example,
Inorganic fibers such as glass fiber and carbon fiber, silk, wool, cotton,
Natural fiber such as hemp, regenerated fiber such as rayon fiber, semi-synthetic fiber such as acetate fiber, polyamide fiber, polyvinyl alcohol fiber, acrylic fiber, polyester fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber,
Synthetic fibers such as polyurethane fibers, polyethylene fibers, polypropylene fibers, polymethylpentene fibers, aromatic polyamide fibers, or composite fibers composed of two or more resin components and exhibiting crimping or splitting properties can be used. When the fiber sheet of the present invention is used as a molding base for fiber-reinforced plastic, it preferably contains fibers having higher tensile strength and tensile modulus than plastic, and has a single fiber strength (JIS L 1015 (chemical fiber The tensile strength specified in the staple test method) is 8.3 cN
It is preferable to use a high-strength fiber of / dtex or more.
Examples of the high-strength fiber include a polyacrylate fiber, an ultrahigh-molecular-weight polyethylene fiber, a polyarylate fiber, a high-strength vinylon fiber, a para-aramid fiber, a copolyamide fiber, and a polyparaphenylenebenzobisoxazole fiber. The high-strength fiber may be composed of a single fiber. However, it is preferable that a plurality of single fibers exist in a converged state because the fiber is superior in strength.

[0011] The fiber sheet of the present invention can be produced by a conventional method. For example, the nonwoven fabric containing the heat-adhesive fiber of the present invention can be manufactured as follows. First, a fiber web containing the above-mentioned heat-adhesive fiber is formed. As a method of forming the fiber web, for example, there are a dry method such as a card method, an air lay method, a spun bond method and a melt blow method, and a wet method. The fiber length varies depending on the method of forming the fiber web, and when the fiber web is formed by the dry method (excluding the spun bond method and the melt blow method), 20
When a fiber having a length of about 160 mm is used and the latter is formed by a wet method, a fiber having a length of about 1 to 30 mm is used. Further, after forming these fiber webs, different types of fiber webs may be laminated, such as laminating fiber webs having different production methods or laminating fiber webs having different fiber compositions. When the fiber sheet of the present invention is used as a molding substrate for fiber-reinforced plastic, it is preferably a nonwoven fabric in which a plurality of single fibers are present in a converged state as described above. The fibrous web is, for example, (1) a method of using a non-crimped single fiber to cause poor opening by a well-known card method or the like, and (2) fixing a tow with an adhesive or the like, and then cutting the tow to a predetermined length. Then, a method of forming a fiber web from the fibers containing the tow in the converged state by a card method or the like (the opening of the tow is insufficient and a plurality of single fibers are present in a converged state); A method of forming a fiber web containing unspread fibers (a plurality of single fibers are present in a converged state) by, for example, increasing the clearance; and (4) a fiber web (preferably including a heat-adhesive fiber). Fiber web) After spraying the window, (present in a single fiber state of convergence plurality of insufficient opening of the tow) a method of forming a fiber web by a card method, can be produced by such. Among them, the method (4) is preferable because the fiber web (fiber web containing heat-adhesive fibers) and the tow can be uniformly mixed. In addition, the orientation direction of the fiber constituting the fiber web may be one direction, or the orientation may be non-direction by a cross layer or the like, but if the orientation is non-direction, This is suitable because it can be used as a molding base for fiber-reinforced plastics having excellent strength.
Then, by heat-bonding the heat-bondable fibers contained in the fiber web manufactured as described above,
Nonwoven fabrics can be manufactured. The heat treatment for thermally bonding the heat-bondable fibers is preferably performed at a temperature higher than the glass transition temperature of the essential polyester resin by 20 ° C. or more. Such heat treatment, for example, dryer,
It can be carried out by a hot air dryer, a dryer with suction or the like. In addition, it is preferable to apply the pressure simultaneously with the heat treatment or to apply the pressure after the heat treatment so that the essential polyester resin is sufficiently bonded. This pressure treatment can be performed by, for example, a calender roll, a flat press machine, or the like. In addition to the heat treatment as described above, other bonding methods such as entanglement with a needle punch or a fluid stream (particularly a water stream) or adhesion with a binder such as emulsion or latex may be used in combination. For example, when the fiber sheet of the present invention is used as a molding substrate for a fiber-reinforced plastic, it is preferable that the fiber sheet is entangled with a needle punch before heat treatment, because delamination of the nonwoven fabric can be prevented. This preferred needle punch is preferably carried out at a needle density of about 5 to 10 needles / cm ² so that delamination of the nonwoven fabric can be prevented and the formability of the nonwoven fabric is not impaired. The areal density of the nonwoven fabric of the present invention that can be produced in this manner is 50 to 500 g /
Suitably, it is about m ² . For example, when used as a molding substrate for fiber-reinforced plastics,
About 250 g / m ² is appropriate.

[0012] Since the fiber sheet of the present invention contains the above-mentioned heat-adhesive fiber, it has low resilience and excellent deformability. Therefore, the fiber sheet of the present invention can be used for various applications such as a molding substrate for fiber-reinforced plastic and a molding substrate for fiber-reinforced concrete, which do not require resilience. In addition, dyeing, buffing, pigment coloring with a binder,
Post-processing such as kneading, electret processing, and hydrophilization may be performed so as to be suitable for various uses.

An embodiment of the present invention will be described below, but the present invention is not limited to the following embodiment.

[0014]

(Example 1) In a conventional composite melt spinning apparatus.
The diol component is ethylene glycol 5 as the sheath component.
From 2 mol% and 48 mol% of 1,2-propanediol
The dibasic acid component contains 76 mole% of terephthalic acid and
Amorphous essential polyester consisting of 24 mol% of tallic acid
Ter-based resin (glass transition temperature: 79 ° C, number average molecular weight:
19,000), and polyethylene core as the core component.
Using phthalate (intrinsic viscosity = 0.65)
The ratio (mass ratio) is 1: 1, the spinning temperature is 285 ° C, and the discharge amount is
Composite melt spinning under the condition of 1.4 g / min per hole
The yarn was implemented. After cooling the spun yarn, take-off speed
Takes at 788 m / min and has a fineness of 17.8 dtex
An undrawn core-sheath type thermoadhesive fiber was obtained. Then, this unstretched
The core-sheath type thermo-adhesive fibers are bundled to form a 17.8 ktex tow.
And then stretched 4 times at a stretching temperature of 80 ° C.
A heat-adhesive fiber was obtained. Then, use the push-in crimper
To give a crimp to the stretched core-sheath type thermoadhesive fiber (1).
5 pieces / inch) and then cut to a fineness of 4.4 dte
x, stretched core-sheath type thermo-adhesive fiber having a fiber length of 51 mm (tensile
Strength: 2.7 cN / dtex, elongation: 35%, cross section
(Shape: circular). Next, the stretched core-sheath type heat-adhesive fiber
Open 100% of the fiber using a carding machine, and then
The direction of fiber orientation is set to non-direction by ear,
60g / m ^TwoWas formed. Then
A plurality of single fibers (fineness:
1.67 dtex, single fiber strength: 9.8 cN / dte
x) converged fineness 250 tex, high strength 50 mm long
Power vinylon fiber tow (unitilica, vinylon AB)
1m^Two540g per unit to form a scattered fiber web
Done. Next, this scattered fiber web is
After opening, the orientation direction of the fiber is
An oriented, scattered cross lay web was formed. Next
Then, the needle density is 5 needles / c for this scattered cloth lay web.
m^TwoThe needle density is 130g /
m^TwoEntangled nonwoven fabric ((stretched core-sheath type
Amount): (mass of high strength vinylon fiber) = 1: 9)
did. This entangled nonwoven fabric contains multiple high-strength vinylon fibers.
The book was in convergence. Then, this entangled nonwoven
The Reliant Press Machine (Asahi Textile Machinery Co., Ltd., J
R-1000LTS-E), heated at 125 ° C
And then pressurized at a surface pressure of 19.6 kPa and stretched
Sheath component of thermo-adhesive fiber, that is, essential polyester resin
Is thermally bonded to form an adhesive entangled nonwoven fabric of the present invention (area density: 13
0 g / m^Two, Thickness: 1 mm).

(Example 2) As a sheath component, a diol component was ethylene glycol 47 mol% and neopentyl glycol 5
3 mol%, and the dibasic acid component is terephthalic acid 54
Mol% and 46 mol% of isophthalic acid, a non-crystalline essential polyester resin (glass transition temperature: 70 ° C.,
Number average molecular weight: 16,000),
Exactly in the same manner as in Example 1, a stretched core-sheath type thermoadhesive fiber having a fineness of 4.4 dtex and a fiber length of 51 mm (tensile strength:
2.9 cN / dtex, elongation: 40%, cross-sectional shape: circular). Then, in exactly the same manner as in Example 1, an entangled nonwoven fabric (a plurality of high-strength vinylon fibers are present in a converged state,
(Mass of stretched core-sheath type thermo-adhesive fiber) :( mass of high-strength vinylon fiber) = 1: 9), and then the sheath component of the stretched core-sheath-type thermo-adhesive fiber is heat-bonded. (Areal density: 130 g / m ² , thickness: 1 mm).

Example 3 As a sheath component, a diol component is composed of 69 mol% of ethylene glycol and 31 mol% of 1,4-cyclohexanedimethanol, and a dibasic acid component is composed of 100 mol% of terephthalic acid. Except for using the essential polyester resin (glass transition temperature: 81 ° C.), the fineness was 2 dte in the same manner as in Example 1.
x, a stretched core-sheath type thermoadhesive fiber having a fiber length of 38 mm (tensile strength: 3.1 cN / dtex, elongation: 51%, cross-sectional shape: circular). Then, in exactly the same manner as in Example 1, an entangled nonwoven fabric (a plurality of high-strength vinylon fibers are present in a converged state, (mass of stretched core-sheath type thermoadhesive fiber): (mass of high-strength vinylon fiber) = 1) : 9), the sheath component of the stretched core-sheath type heat-adhesive fiber is heat-bonded, and the bonded entangled nonwoven fabric of the present invention (area density: 130 g / m ² , thickness: 1 mm)
Was manufactured.

(Comparative Example 1) The sheath component is made of a polyester resin containing 100 mol% of ethylene glycol as a diol component (containing no tertiary carbon and / or quaternary carbon as the diol component), and the core component is Thermal adhesive fibers made of polyethylene terephthalate (Unitika 4080,
Fineness: 4.4 dtex, fiber length: 51 mm, tensile strength: 3.2 cN / dtex, elongation: 55%, cross-sectional shape:
(Circle) was prepared. Then, in exactly the same manner as in Example 1, an entangled nonwoven fabric (a plurality of high-strength vinylon fibers are present in a converged state, (mass of stretched core-sheath type thermoadhesive fiber): (mass of high-strength vinylon fiber) = 1) : 9), the sheath component of the heat-adhesive fiber was thermally bonded to produce an adhesively entangled nonwoven fabric (area density: 130 g / m ² , thickness: 1 mm).

(Comparative Example 2) The sheath component is made of a polyester resin comprising ethylene glycol and 1,4-butanediol as diol components (containing no tertiary carbon and / or quaternary carbon as diol components). , A heat-adhesive fiber whose core component is made of polyethylene terephthalate (Unitika 7080, fineness: 4.4 dtex, fiber length: 51 m)
m, tensile strength: 3.3 cN / dtex, elongation: 60
%, Cross-sectional shape: circular). Then, in exactly the same manner as in Example 1, an entangled nonwoven fabric (a plurality of high-strength vinylon fibers are present in a converged state, (mass of stretched core-sheath type thermoadhesive fiber): (mass of high-strength vinylon fiber) = 1) : 9), the sheath component of the heat-adhesive fiber was thermally bonded to produce an adhesively entangled nonwoven fabric (area density: 130 g / m ² , thickness: 1 mm).

(Evaluation of the adhesively entangled nonwoven fabric) First, Examples 1 to 3
And each of the adhesive entangled nonwoven fabrics of Comparative Examples 1 and 2
The sample was cut into a rectangle of 0 cm and a width of 20 cm to prepare a sample. Next, an unsaturated polyester containing 1% of a curing agent (Polyoxide RM, manufactured by Kayaku Akzo Co., Ltd.) (Corotect CT-100-RS, Dainippon Ink and Chemicals, Inc.)
Was impregnated in each sample, and each sample was folded in an S-shape (see FIG. 1) by a defoaming roll. The time required for this operation and the state of the sample after folding were observed. The results were as shown in Table 1.

[0020]

【table 1】

As apparent from Table 1, a fiber sheet (adhesive entanglement) heat-bonded with a heat-bonding fiber having an essential polyester resin containing a diol component containing a tertiary carbon and / or a quaternary carbon. Nonwoven fabric) had low resilience and excellent deformability. Therefore, it was found that this adhesively entangled nonwoven fabric can be suitably used as a molding base for fiber reinforced plastic. Further, from the results of Examples 1 to 3, it was found that when the diol component containing tertiary carbon and / or quaternary carbon was composed of a chain aliphatic compound, the resilience was lower and the deformability was excellent.

[0022]

As described above, the heat-adhesive fiber of the present invention can be bonded so as to have low resilience and excellent deformability. for that reason,
The fiber sheet bonded with the heat-adhesive fibers has low resilience and excellent deformability. The fiber sheet of the present invention can be suitably used as a molding base for fiber reinforced plastic.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a folded state of a sample.

[Explanation of symbols]

 1 sample (fused and entangled nonwoven fabric)

Continued on the front page F term (reference) 4F205 AD05 AD16 HA14 HC06 HC13 4L035 BB32 BB40 BB89 BB91 CC20 DD19 EE01 FF05 4L041 AA07 AA15 AA20 BA02 BA05 BA21 BA49 BA59 BC04 BD01 BD03 BD11 BD20 CA06 CA14 DD01 DD05 A15A02A BA09 BB09 CB01 CB10 CC13

Claims (6)

[Claims] 1. A thermo-adhesive fiber comprising a polyester resin containing a diol component containing tertiary carbon and / or quaternary carbon. 2. The heat-adhesive fiber according to claim 1, wherein the diol component containing a tertiary carbon and / or a quaternary carbon comprises a chain aliphatic compound. 3. The heat according to claim 1, wherein the content of the diol component containing tertiary carbon and / or quaternary carbon is 30 mol% or more in the diol component. Adhesive fiber. 4. A polyester resin containing isophthalic acid as a dibasic acid component.
4. The heat-bondable fiber according to any one of items 1 to 3. A fiber sheet, which is bonded by the heat-bondable fiber according to any one of claims 1 to 4. 6. The fiber sheet according to claim 5, wherein the fiber sheet is used as a molding substrate for fiber reinforced plastic.