JPH0730491B2 - Composite molded product - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fiber composite molded article which is three-dimensionally molded on various curved surfaces.

(Prior Art) Conventionally, as this type of technology, as disclosed in Japanese Utility Model Publication No. 435373, a polypropylene composite fiber having a relatively low melting point is used as a base cloth and a pile yarn to form a fiber composite molding by a heat molding process. As disclosed in Japanese Patent Laid-Open No. 51-13126, a web made of high melting point fibers and a web made of low melting point fibers such as polypropylene and polyethylene are superposed on the bottom surface and entangled with a needle punch. A fiber composite molded article obtained by heating and pressurizing at a temperature higher than the melting point of the low-melting point fiber to give the fiber a bundle and a shape-retaining property. An example is a fabric molded article obtained by thermoforming the formed fabric.

(Problem to be Solved by the Invention) A problem to be solved by the present invention is a problem in the technique exemplified in (Prior Art), that is, Jpn.
In the technology disclosed in No. 5373, in the hot molding of a fabric made of polypropylene fiber, a molded product is formed by imparting the converging property of the base fabric and the pile part by welding by melting by heating above the melting point of the base fabric part polypropylene fiber. The fiber cannot follow large deformation due to melting, and if large deformation occurs, blurring and perforation will occur. Further, in the technique disclosed in Japanese Patent Laid-Open No. 51-13126, a web made of high melting point fibers and a bottom portion made of low melting point fibers is heated and pressed at a temperature higher than the melting point of the low melting point fibers to be molded. It is due to melting,
Large deformation cannot be followed, and there is a possibility that holes, tears, etc. will occur.

Furthermore, in the case of molding accompanied by melting, the texture of the molded product becomes coarse and rigid, which is not preferable. In the technique disclosed in Japanese Patent Laid-Open No. 52-15698, which is a molded article composed of highly oriented undrawn yarn, there is no melting, no perforation, no breakage, etc.
As for the surface finish of the molded product, only a highly oriented undrawn yarn is obtained, and it cannot be a product excellent in decorativeness and aesthetics.

The present invention solves the above-mentioned problems and enables molding in a short process,
The present invention relates to a fiber composite molded article having excellent surface decorativeness and aesthetics, which can sufficiently follow large deformation three-dimensional molding.

(Means for Solving Problems) The present invention has a high birefringence (Δn) of 0.05 to 0.140 obtained by melt spinning a fiber-forming polyester in which at least 70% of repeating units are butylene terephthalate. A composite molded article comprising a fiber sheet in which oriented non-stretched yarns are arranged on a base fabric or mainly on the back surface, and fibers having a higher softening point than the fibers are arranged on the pile yarns or mainly on the surface. According to the present invention, by using a sheet containing a highly oriented undrawn yarn obtained by spinning a butylene terephthalate-based polyester under specific spinning conditions, the process operation is simple, and molding can be performed at a relatively low temperature and low pressure, It is possible to obtain a fiber composite molding having an excellent appearance and texture, which is unlikely to tear or peel even in a large molding site. Molding is possible at a lower temperature than when using highly oriented undrawn yarn from ethylene terephthalate polyester,
A high softening point fiber that discolors or deteriorates at a high temperature can also be used for the pile portion and the surface portion, and the selection range can be expanded in terms of aesthetics and decorativeness to obtain a composite molded article. Further, the composite molded article of the present invention, the fiber sheet, by utilizing its large deformation followability and surface decoration,
By integrally molding with a plastic sheet or film and then three-dimensionally molding, it can also be used for a composite molded article composed of a plastic sheet and a fiber sheet, which has excellent shape retention and surface decoration.

The polyester used in the present invention is a polyester containing terephthalic acid as a main acid component and butylene glycol as a main glycol component, and is a fiber-forming polyester in which at least 70 mol% of repeating units are butylene terephthalate. A particularly preferred polyester in the present invention is polybutylene terephthalate consisting only of butylene terephthalate units, but other than that, a copolymerized polybutylene terephthalate obtained by copolymerizing a conventionally known dicarboxylic acid component, dioxy component and oxycarboxylic acid component. Alternatively, other homopolyester of polybutylene terephthalate or copolymerized polybutylene terephthalate, a mixed polyester obtained by melt-mixing a copolymerized polyester, polybutylene terephthalate,
An amide bond in the copolymerized polybutylene terephthalate,
It also includes a copolymer having an ether bond, a carbonate bond, and the like, and a polybutylene terephthalate containing a small amount of polyester, polyether ester, and the like having a fiber-forming ability.

Birefringence (Δn) of 0.05 to 0.140 from the above polyester
In order to produce the highly oriented unstretched butylene terephthalate-based polyester fiber, it is necessary to appropriately set the spinning conditions. Usually, it is convenient to obtain it by high-speed spinning at 500 to 3000 m / min. The birefringence (Δn) is calculated by the following formula, using sodium D line (wavelength 589 mμ) as a light source and arranging the filaments diagonally.

Here, n: the number of interference fringes depending on the degree of orientation of the polymer molecular chain γ: retardation obtained by Berek compensator for an orientation that does not lead to interference fringes λ: wavelength of sodium D line α: fiber diameter birefringence (△ n) The physical property range of the fiber of 0.05 to 0.140 is
At the same time, it is preferable to arbitrarily select within the range depending on the type, thickness, molding method, and molding temperature of the composite molded product that is molded as a composite material. When Δn is less than 0.05, it is unstable with respect to the temperature during molding, and the resistance as a base fabric as a molded product is too small. Further, if it is 0.140 or more, the elongation at the time of molding is small, which is not preferable in terms of large deformation followability.

The softening point of the fiber means a temperature at which the fiber is apt to be rapidly deformed when heated at a constant rate, and the measurement is performed by the following method. When a load of 0.01 g / d is applied to a bundle of one or several fibers and the temperature is raised in air at a rate of 1 ° C / min, contraction occurs when a certain temperature range is reached, but the load Shrink so that is constant. The relationship between the dimensional change of the sample fiber and the temperature at this time is graphed and the temperature at which the change abruptly occurs is determined as the softening point.

It is preferable that the fibers having a high softening point or the yarns composed of these fibers are arranged in a bent shape in the tissue, and as such an example, for example, pile yarns of pile tissue, floating yarns of floating tissue, etc. A fiber sheet in which fibers are mainly arranged on the front surface and highly oriented unstretched butylene terephthalate-based polyester fibers are arranged on the back surface can be mentioned. The fiber sheet may be colored or printed in advance, or may be subjected to treatments such as flame retardancy, stain resistance, water and oil repellency, and polyurethane elastic finish.

As a method of thermoforming the fiber sheet, press molding,
There is vacuum forming and the like, and an appropriate forming temperature is used depending on the type of the high softening point fiber, the value of the birefringence index of the highly oriented undrawn yarn, and the like. Since the fiber composite molded article of the present invention uses the highly oriented undrawn yarn of the polybutylene terephthalate-based polyester for the presence of the high softening point of the surface and the base fabric portion, it is free from eye-catching, perforation, and largely deformed. It has excellent surface decoration and aesthetics. It can be effectively used for women's underwear and brassiere cups.

Furthermore, the fiber sheet for obtaining the fiber composite molded article of the present invention is a composite sheet having excellent surface aesthetics and shape retention by thermoforming after being integrally laminated with a plastic sheet or a plate or film. It can be used for molded products.

On the other hand, as the plastic sheet or plate, all commonly used thermoplastic materials such as vinyl chloride resin, ABS resin and polyolefin resin are used. If desired, a plasticizer, a flame retardant, an antistatic agent, an inorganic filler, a nucleating agent, a stabilizer, etc. may be blended and used in the material of the plastic sheet. Further, as an adhesive for adhering this plastic sheet or plate to the fiber sheet, it has a high affinity for the fiber and the plastics and has sufficient adhesive strength, and also has an appropriate thermoplasticity after curing. It is preferable to have one.

As a method of adhesion, a method such as dry laminating or wet laminating can be considered, and a heat-melt type film-like or powder-like adhesive can also be used. It is also possible to carry out adhesive lamination with a fiber sheet at the time of molding and manufacturing a plastic sheet or plate. Further, as a method for thermoforming the laminated sheet obtained as described above,
There are press molding, vacuum molding, etc., and an appropriate molding temperature is used depending on the type of plastics.

The heating means may be either wet heat or dry heat. The three-dimensional structure molded by the method of the present invention is a product having excellent appearance and texture due to the presence of the fiber layer on the surface, and in the molding step, excessive pressure is not required, and the fiber sheet after molding is Since the force to return to the original shape is almost zero, it does not deform or peel off between each layer, and it is possible to obtain a beautiful molded product that is faithful to the original mold of molding, automobile interior parts, decorative panels for furniture Good results are obtained as toys, toys and other molded products.

(Example) 1. Bibutylene terephthalate having an intrinsic viscosity of 0.91 was melt-spun at a melting temperature of 260 ° C and a spinning speed of 2000 m / min to obtain a birefringence index.
A multifilament yarn of 0.12 75 denier 36 filaments was obtained. This yarn is used as the ground part, and wool is used for the pile part to knit a velor structure and have a basis weight of 300 g / m ²
I got the knitted fabric. The fabric was heated to 120 ° C. and three-dimensionally molded into a hemisphere having a radius of 10 cm. It was possible to obtain a hemispherical shape-retaining composite product in which there is no misalignment of surface wool and no dripping of the surface condition.

2. Polybutylene terephthalate having an intrinsic viscosity of 0.91 is melt-spun at a melting temperature of 260 ° C and a spinning speed of 1500 m / min to obtain a birefringence index.
A 0.95 75 denier / 36 filament multifilament yarn was obtained. Use this yarn as the ground part,
A velor structure was knitted with a single circular knitting machine using a 75 denier / 36 filament polyester calcined yarn in which the pile portion was dyed in a yarn state to obtain a pile knitted fabric having a basis weight of 300 g / m ² . A commercially available two-component reactive urethane adhesive (Diabond 3U07) was applied to this knitted fabric to a solid content of 40 g / m ² , and a polyolefin foam resin plate (Toray Pef; polypropylene 30 times foam plate, 3 mm thickness) was applied. Was laminated and then dried to obtain a laminated plate. After heating this laminated plate to 130 ° C., vacuum forming was performed using a vacuum forming die having a curved shape.

Polybutylene terephthalate fiber expands three times or more under this molding temperature, and the stress at that time is extremely small, and even if it has a curved surface shape, it can be reasonably molded, and there is no distortion after molding and a beautiful finished three-dimensional molding. Goods have been obtained. This molded product is sufficiently durable as an automobile interior product, has an excellent appearance and texture, and can be used for an instrument panel, a door rim pillar, a ceiling and the like.

(Effect of the invention) As described above, a highly oriented undrawn yarn having a birefringence of 0.05 to 0.140 is formed on a base fabric or mainly on the back surface, which is made of a fiber-forming polyester in which at least 70 mol% of repeating units are butylene terephthalate. By placing a fiber sheet having a softening point higher than that of the pile yarn or a fiber sheet mainly on the surface, a three-dimensionally molded composite article is formed by thermoforming, which is excellent in surface decoration, misalignment, It will be a molded product with no blinding.

Claims (2)

[Claims] 1. A highly oriented undrawn yarn having a birefringence (Δn) of 0.05 to 0.140 obtained by melt spinning a fiber-forming polyester having at least 70% of repeating units consisting of butylene terephthalate, as a base fabric, Alternatively, a composite molded article mainly composed of pile fibers or a fiber sheet, which is arranged on the back surface and has a softening point higher than that of the fibers, is mainly arranged on the front surface. 2. A birefringence index (Δn) of a highly oriented undrawn yarn obtained by melt spinning a fiber-forming polyester having at least 70% of repeating units consisting of butylene terephthalate.
The composite molded article according to claim 1, which is 0.10 to 0.140.