JPH04353525A - Blended yarn for composite and formed product thereof - Google Patents

Abstract

PURPOSE:To provide a forming precursor having rich flexibility and capable of being readily formed into complicated shapes, and to provide a fiber- reinforced formed product having excellent impact and vibration resistances. CONSTITUTION:A forming precursor comprising blended yarns of continuous thermoplastic elastomer fibers with continuous reinforcing fibers and a sheet-like product produced therefrom, and a thermally formed product produced from the precursor.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention has flexibility using a thermoplastic elastomer as a matrix, and has excellent impact resistance.
The present invention also relates to a mixed fiber yarn that provides a composite that also has excellent vibration damping properties, and a molded product thereof.

0002

BACKGROUND OF THE INVENTION Conventionally, a combination of thermosetting resin and reinforcing fibers has been commonly used as a composite, but such a system has a problem of low fracture toughness. Therefore, in order to solve the above-mentioned problems, the use of a thermoplastic resin with high fracture toughness as a matrix has been studied and is being put into practical use. However, prepreg, which is made by impregnating continuous reinforcing fibers with thermoplastic resin, is very stiff and can often be difficult to mold into complex shapes. In order to solve this problem, a blended fiber yarn for composites, in which thermoplastic resin is made into continuous fibers and mixed with continuous reinforcing fibers, was published in Japanese Patent Application Laid-Open No. 60-2090.
33 and Japanese Patent Application Laid-Open No. 60-209034. However, there is no disclosure regarding the use of thermoplastic elastomers. The composite molded article obtained in the above-mentioned publication is still rigid, and still needs to be improved if flexibility and impact resistance are required. On the other hand, in the past, composites using elastomers have often been a combination of vulcanized elastomers and reinforcing fibers. That is, these are products that use a vulcanized elastomer and reinforcing fibers such as polyester fibers, aramid fibers, steel fibers, etc., as typified by belts, tires, and the like. On the other hand, as a composite using a thermoplastic elastomer, a stampable sheet of thermoplastic polyurethane and carbon fiber fabric is known. However, there is no disclosure of a mixed fiber yarn of thermoplastic elastomer fibers and high-strength reinforcing fibers or a molded product using the same.

0003

[Problems to be Solved by the Invention] Conventional thermosetting and thermoplastic composites other than elastomers, when flexibility, impact resistance and vibration damping properties are particularly required,
Unable to obtain satisfactory characteristics. On the other hand, when a vulcanized elastomer having the above characteristics is used, there is a problem in moldability. That is, it is extremely difficult to impregnate reinforcing fibers, vulcanize them, and mold them into a predetermined complex shape. In addition, stampable sheets made by impregnating polyurethane into carbon fiber fabrics are also suitable for forming flat objects.
Depending on the woven structure, it may be very difficult to mold it into a complex shape.

0004

[Means for Solving the Problems] As a result of intensive research to solve the above problems, the present invention has been achieved. That is, the present invention provides a blended yarn of continuous thermoplastic fibers and continuous reinforcing fibers, in which the continuous thermoplastic fibers have a tensile modulus of 10 kg/cm2 or more and 400 kg/cm2 or less in a bulk state, and a tensile elongation of 200 kg/cm2 or less. % or more and 650% or less of thermoplastic elastomer resin spun into continuous thermoplastic elastomer fibers, and a sheet-like product obtained from the mixed fiber yarn,
It is a molded article obtained by heating the mixed yarn or sheet-like material to a temperature equal to or higher than the melting point of the thermoplastic elastomer fibers, applying pressure, and impregnating the reinforcing fibers with the thermoplastic elastomer.

The present invention will be explained in detail below. The thermoplastic fibers used in the present invention are in bulk according to ASTM
Tensile modulus measured by D638 is 10 kg/
It is a continuous multifilament fiber made by melt-spinning a thermoplastic elastomer resin having a weight of 200 kg/cm2 or more and a tensile elongation of 200% or more and 650% or less. The tensile modulus of the above resin is 10kg/cm2
If it is less than 400kg/cm2, it will not become a fiber.
Above this, a composite having flexibility and impact resistance cannot be obtained. In addition, if the tensile elongation is 650% or more, it will stretch well even if it becomes fibrous, so it will not be able to maintain its shape. On the other hand, if it is less than 200%, satisfactory performance cannot be obtained in the composite.

[0006] As this thermoplastic elastomer resin,
There are thermoplastic polyurethane elastomers, polyolefin elastomers, polyester elastomers, polyamide elastomers, etc., but they may be selected depending on the purpose and are not particularly limited. Multifilament fibers obtained by melt-spinning these resins using a conventional method are used. The above-mentioned fibers are preferably wound up without being drawn, and the winding speed is from 50 m/min to 4000 m/min, preferably from 500 m/min to 1000 m/min, and it is preferable to form undrawn yarns. On the other hand, it is preferable that the fiber has a low thermal shrinkage, and the dry shrinkage rate at a temperature 50° C. lower than the melting point is 30% or less, preferably 15% or less. The single yarn denier of the above-mentioned fiber is 1 to 30 denier and the number of filaments is about 5 to 1000, and is not particularly limited. It is preferable to combine these fibers as necessary and align them to a predetermined mixing ratio.

On the other hand, examples of continuous reinforcing fibers include glass fiber, carbon fiber, aramid fiber, high-strength polyethylene fiber,
Examples include high-strength polyester fibers, but there are no particular limitations as long as they have a melting point higher than the melting point of the thermoplastic elastomer fibers used. These reinforcing fibers are continuous multifilaments, and each may be used alone, or two or more types may be used in combination. These reinforcing fibers are preferably treated to improve adhesion to the thermoplastic elastomer.

[0008] As a method for mixing the continuous thermoplastic elastomer fibers and the continuous reinforcing fibers, a known method of turbulence agitation using air is simple and efficient, but the method is not particularly limited to this. isn't it. On the other hand, the blending ratio of continuous reinforcing fibers and continuous thermoplastic elastomer may be selected depending on the purpose, but it is not recommended to increase the blending ratio too high because increasing the blending ratio of reinforcing fibers will impair the flexibility of the molded product. do not have. Preferably, the mixing ratio of reinforcing fibers is 5 to 60% by volume.
Good. The mixed fiber yarn obtained by mixing both of the above-mentioned fibers is knitted and woven to form a sheet-like material, that is, a cloth-like material, particularly preferably into a multiaxial laminated cloth, or it is cut into 5-200 mm pieces to form a mat-like material, or Use the blended yarn as a molding material. For example, when using mixed yarn as is, filament winding, pultrusion molding, and sheet-like products,
Taking advantage of its flexibility, it is possible to press mold into complex shapes, autoclave mold, etc. Moreover, the mat-like material can also be applied to stamping molding. However, the molding method is not limited to these, and it is necessary to select a method that suits the shape of the desired molded product.

[0009] The molding conditions at this time include a temperature above the melting point of the continuous thermoplastic elastomer, preferably 20°C to 50°C below the melting point, and a pressure of 1 to 50 kg/cm2, preferably 1 to 10 kg/cm2, Mold for 1 to 60 minutes, preferably 1 to 10 minutes. Since the molding material is a mixed yarn of reinforcing fibers and thermoplastic fibers, it can be impregnated and molded at relatively low pressure and in a short time, but it is necessary to select molding conditions suitable for the molding method. In this case, since the molding material is in a fibrous state, it can be applied to complex shapes and molded products of various shapes can be obtained. The molded article thus formed becomes a thermoplastic elastomer composite reinforced with various reinforcing fibers as described above. This molded product has the flexibility of an elastomer and has excellent impact resistance. In addition, the use of elastomer has an effect on vibration damping, which can be applied to timing belts, drive belts, shoe soles, etc.
Applicable to sports equipment.

0010

【Example】

(Example 1) Pelprene P-15, a polyester elastomer manufactured by Toyobo Co., Ltd., was used as a continuous thermoplastic fiber.
0B (tensile modulus measured by ASTM D638 in bulk state: 181 kg/cm 2 , tensile elongation: 500%) was melt spun at a nozzle temperature of 236°C. An undrawn yarn was obtained at a winding speed of 1000 m/min. The single yarn denier was 350 denier and the number of filaments was 48. Three of these thermoplastic elastomer fibers and one 3K carbon fiber (single fiber diameter 6.8 μm) were mixed using an interlacer. The carbon fiber content was 53% by volume (62% by weight). A plain woven fabric was produced using the above mixed yarns at a rate of 20 yarns/inch for both warp and warp. The fabric was pressed in a mold at 230° C. for 3 minutes at a pressure of 10 kg/cm 2 to obtain a composite flat plate with a thickness of 3 mm. The Izod impact strength of this flat plate was measured to be 75 kg-f.
-cm/cm.

(Comparative Example) Nylon 6 was used instead of pelprene in Example 1. This nylon 6 has a tensile modulus of 33,000 kg/cm 2 and a tensile elongation of 30% as measured by ASTM D638 in a bulk state. This nylon 6 was melt-spun at a nozzle temperature of 260°C. POY was obtained at a winding speed of 4000 m/min. The single yarn denier was 350 denier and the number of filaments was 48. Thereafter, a composite flat plate was obtained in the same manner as in Example 1. However, the mold temperature was 245°C. When the Izod impact strength of the obtained flat plate was measured, it was 55
kgfcm/cm. Carbon fiber content is 52
% by volume (62% by weight).

0012

[Effects of the Invention] According to the present invention, a molding precursor (mixed fiber yarn, sheet-like material obtained from the mixed fiber yarn) having a complicated shape and suitable for molding is provided, and The molded body is suitable for applications requiring flexibility, impact resistance and vibration damping properties.

Claims (3)

[Claims] 1. A mixed fiber yarn of thermoplastic continuous fibers and continuous reinforcing fibers, wherein the thermoplastic fibers have a tensile modulus of 10 kg/cm2 or more in a bulk state and 400 kg.
/cm2 or less, tensile elongation is 200% or more, 650%
A mixed fiber yarn for composites, which is characterized by being a thermoplastic continuous elastic fiber spun from the following thermoplastic elastomer resin, and a sheet-like article obtained from the mixed fiber yarn. 2. A sheet-like product obtained from a mixed yarn of thermoplastic continuous fibers and continuous reinforcing fibers, wherein the thermoplastic fibers have a tensile modulus of 10 kg/c in a bulk state.
A composite sheet material obtained from thermoplastic continuous elastic fibers spun from thermoplastic elastomer resin having a tensile elongation of 200% or more and 650% or less. 3. Comprised of reinforcing fibers obtained by thermoforming a sheet-like product obtained from the mixed yarn according to claim 1 or the mixed yarn according to claim 2, and a thermoplastic elastic resin. Molded object.