JP2004025522A - Nonwoven fabric sheet for ceiling upholstery for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester nonwoven fabric sheet which exhibits excellent heat resistance, flexibility and sound absorbing qualities, and excellent moldability, and is especially suitable for a ceiling upholstery for a vehicle. <P>SOLUTION: This nonwoven fabric sheet which exhibits excellent heat resistance, flexibility and sound absorbing properties and excellent moldability, can be formed by laminating a polybutylene terephthalate resin with an intrinsic viscosity [η] in a range of 0.6-1.8 on at least one face of a spun lace nonwoven fabric comprising a polyethylene terephthalate resin fiber with an intrinsic viscosity [η] in a range of 0.4-1.5, and it is especially suitably used as a ceiling upholstery for an automobile. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a nonwoven fabric sheet used as a ceiling interior material for covering an indoor side of a roof of an automobile body.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as interior materials for ceilings of automobiles, 1) A glass fiber mat is adhered to both sides of a sheet-shaped urethane foam for thermoforming with a hot melt film interposed therebetween, and a hot melt film is further interposed on the surface of the glass fiber mat. 2) A polycarbonate film is laminated on both sides of a plate-like urethane foam for thermoforming, and the polyester nonwoven fabric is bonded by melting the polycarbonate film. 3) A styrenic copolymer resin film is laminated on both sides of a semi-rigid plate-like urethane foam for thermoforming, and polyester is melted by melting the styrenic copolymer resin film. Ceiling interior material to which a non-woven fabric is bonded (Japanese Patent Laid-Open No. 11-4887) Publication) it is known items.
As this polyester nonwoven fabric, a polyester nonwoven fabric laminated with low-density polyethylene or high-density polyethylene is used.
[0003]
[Problems to be solved by the invention]
By the way, in general, a ceiling interior material of an automobile is required to simultaneously have good heat resistance, heat insulation, sound absorption, good shape stability, and the like. However, the above-mentioned polyester non-woven fabric is obtained by laminating low-density polyethylene or high-density polyethylene on a polyester non-woven fabric, and is insufficient from the viewpoint of heat resistance, flexibility and sound absorption. As a method for improving this problem, it is conceivable to laminate polyethylene terephthalate on a polyester nonwoven fabric by using polyethylene terephthalate instead of low-density polyethylene or high-density polyethylene used for the laminate layer. However, the resulting laminate layer was hard and poor in flexibility and was not practical, and had problems in molding.
The present invention has been made in view of the above problems, and provides a polyester nonwoven fabric sheet which is excellent in heat resistance, flexibility and sound absorbing properties, and excellent in moldability, particularly suitable for a car interior material for ceilings. The purpose is to do.
[0004]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above-described problems, and as a result, have found that the above object can be achieved by laminating a polyester nonwoven fabric using a specific polybutylene terephthalate resin. It was completed.
That is, the gist of the present invention resides in a nonwoven fabric sheet for a car ceiling interior material, which is obtained by laminating a polybutylene terephthalate resin on at least one surface of a nonwoven fabric made of a polyester resin fiber.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
In the present invention, polyethylene terephthalate resin fibers are suitable as the polyester resin fibers used for the nonwoven fabric.
The polyethylene terephthalate resin (hereinafter referred to as PET) is a polymer obtained by polycondensing terephthalic acid or a terephthalic acid derivative as an acid component and ethylene glycol as a glycol component, and the terephthalic acid component and / or Alternatively, a copolymer in which a part of the ethylene glycol component is replaced with a copolymer component is also included. As the PET, virgin PET, recycled PET, and the like are preferably used. Recycled PET is generally used by crushing a polyethylene terephthalate beverage container (commonly known as a PET bottle) and repelleting it. In the repelletization step, the intrinsic viscosity (η value) decreased due to water absorption, heat history, etc. ) Can be used after being adjusted by solid phase polymerization. Further, the recycled PET can be used by being appropriately mixed with the virgin PET.
[0006]
The intrinsic viscosity [η] of the PET is in the range of 0.4 to 1.5, and preferably in the range of 0.6 to 1.1. When [η] is less than 0.4, the tensile strength of the multifilament, which is a PET resin fiber, is low, and longitudinal cracks are easily generated. When [η] exceeds 1.5, the fluidity is poor at the time of melt extrusion and the yarn breaks. Is not preferred.
[0007]
The nonwoven fabric made of the polyethylene terephthalate resin fiber is not particularly limited, and can be appropriately selected from known nonwoven fabrics such as spunbonded nonwoven fabric, spunlace nonwoven fabric, hot air guard nonwoven fabric, hot embossed guard nonwoven fabric, and melt blown nonwoven fabric. However, a spun-lace nonwoven fabric is preferably used because it has an advantage of being easily extended in the lateral direction.
[0008]
As the spunlace nonwoven fabric (fiber entangled nonwoven fabric), any spunlace nonwoven fabric manufactured by a wet method or a dry method can be used. As the polyethylene terephthalate resin fiber, a multifilament formed by melt-extruding a polyethylene terephthalate resin from a die and performing uniaxial stretching is preferably used. The fiber length is in the range of 10 to 100 mm, preferably 20 to 70 mm, and the fineness is 0.1 to 3 dtex (hereinafter abbreviated as dt), preferably 0.5. ２2 dt. The basis weight of the spunlace nonwoven fabric is in the range of 10 to 200 g / m2, preferably 20 to 150 g / m2.
[0009]
As a spunlaced nonwoven fabric by a wet method, in a wet forming process, a polyethylene terephthalate resin fiber as a raw material is provided together with water on a mesh-shaped wire transporting band of a predetermined mesh to form a fiber web. The felt comes into contact with the wire transport band, and due to the difference in surface roughness between the wire transport band and the felt, the fiber web on the wire transport band is once transferred onto the felt, and the fiber web is moved to the fiber entanglement step by the felt. Be transported. In the fiber entanglement step, a wire transport band that circulates between a plurality of rolls is provided, and the fiber web is transferred from the felt to the wire transport band. Then, a water jet is applied to the fiber web conveyed by the wire conveyance band, and the fibers of the fiber web are entangled to form a nonwoven fabric. From the fiber entanglement step, a nonwoven fabric made of polyethylene terephthalate resin is further transferred to a drying step and dried.
[0010]
In addition, as a spunlace nonwoven fabric by a dry method, a fiber web is formed by a card machine provided in one or more stages, and the fiber web is conveyed and sent to a fiber entanglement step. In this fiber entanglement step, a fiber web is conveyed by a wire conveyance band of a predetermined mesh, and a water jet is applied to the fiber web to entangle the fibers to form a nonwoven fabric. The nonwoven fabric of polyethylene terephthalate resin formed in the fiber entanglement step is further transferred to a drying step and dried.
[0011]
The polyethylene terephthalate resin fiber may contain rayon fiber in an amount of 30 wt% or less, preferably 5 to 20 wt%. If the content of the rayon fiber is more than 30% by weight, the weather resistance decreases, which is not desirable.
[0012]
In the present invention, a laminated sheet is formed by laminating a polybutylene terephthalate resin film having a specific intrinsic viscosity on at least one surface of the nonwoven fabric made of the polyester resin fiber. As a method for laminating the above polybutylene terephthalate resin film, an extrusion lamination method, a dry lamination method, a thermocompression lamination method, or the like can be used, but the extrusion lamination method is preferable in terms of moldability. The thickness of the laminate layer is usually in the range of 10 to 100 μm, preferably in the range of 10 to 50 μm.
[0013]
The polybutylene terephthalate resin (hereinafter sometimes abbreviated as PBT) used for the laminate layer is a polymer obtained by polycondensing terephthalic acid or a terephthalic acid derivative as an acid component and tetramethylene glycol as a glycol component. And a copolymer in which a part of the terephthalic acid component and / or the tetramethylene glycol component is replaced with a copolymer component.
[0014]
The intrinsic viscosity [η] of the PBT used in the present invention is 0.6 or more, preferably in the range of 0.6 to 1.8, and more preferably in the range of 0.8 to 1.5. When the intrinsic viscosity [η] of the PBT is less than 0.6, the PBT has high crystallinity, so that the film forming stability is deteriorated. When the intrinsic viscosity [η] exceeds 1.8, the processability is inferior. Absent.
[0015]
In the present invention, it is desirable to mix a small amount of low-density polyethylene with the above-mentioned PBT because the molding stability of the PBT can be improved. The amount of the low-density polyethylene is in the range of 5 to 20 parts by weight of the low-density polyethylene based on 100 parts by weight of the PBT. If the amount of the low-density polyethylene is less than 5 parts by weight, the effect of the addition of the polyethylene is not exhibited. If the amount is more than 20 parts by weight, the dispersibility deteriorates and the heat resistance of the PBT decreases, which is not desirable. As the low-density polyethylene, a linear low-density polyethylene, a branched low-density polyethylene, or the like is used. The low-density polyethylene has a melt flow rate (hereinafter abbreviated as MFR) in the range of 0.5 to 20 g / 10 minutes.
[0016]
The polyethylene terephthalate resin and the polybutylene terephthalate resin used in the present invention include an antioxidant, an ultraviolet absorber, a light stabilizer, a lubricant, an antistatic agent, a pigment, a flame retardant, and an inorganic material without departing from the spirit of the present invention. Commonly used additives such as a filler, a nucleating agent, a foaming agent and a dispersant may be blended.
[0017]
【Example】
Example 1
An intrinsic viscosity [η] is formed on one side of a spunlace nonwoven fabric (basis weight: 30 g / m2) composed of polyethylene terephthalate resin fiber having an intrinsic viscosity [η] of 0.65 (melting point = 254 ° C., fiber length: 30 mm, fineness: 2 dt). Using a polybutylene terephthalate resin having a melting point of 1.30 (melting point = 220 ° C.), a polybutylene terephthalate laminate layer (30 μm) was laminated at 265 ° C. by an extrusion lamination method to obtain a nonwoven fabric sheet.
The moldability of the laminate layer of polybutylene terephthalate was good, and the obtained nonwoven fabric sheet had good heat resistance, flexibility and sound absorbing effects.
[0018]
Comparative Example 1
Example 1 was repeated in the same manner as in Example 1, except that a polyethylene low-density polyethylene (30 µm) was laminated at 240 ° C by extrusion lamination using a branched low-density polyethylene instead of the polybutylene terephthalate resin.
The obtained nonwoven fabric sheet had insufficient heat resistance, flexibility and sound absorbing effect as compared with the nonwoven fabric sheet of Example 1.
[0019]
Comparative Example 2
Example 1 was repeated in the same manner as in Example 1 except that a polyethylene terephthalate laminate layer (30 µm) was laminated at 285 ° C by extrusion lamination using polyethylene terephthalate instead of the polybutylene terephthalate resin. Polyethylene terephthalate had poor film moldability, and the resulting laminate layer was hard and poor in flexibility, and a sufficiently satisfactory laminate layer could not be obtained.
The obtained nonwoven fabric sheet had an insufficient flexibility effect as compared with the nonwoven fabric sheet of Example 1.
[0020]
【The invention's effect】
As described above, the nonwoven fabric sheet of the present invention is excellent in heat resistance, flexibility and sound absorption by laminating a polybutylene terephthalate resin having a specific intrinsic viscosity on at least one surface of a nonwoven fabric made of polyester resin fibers. A nonwoven fabric sheet having excellent moldability can be formed, and it is particularly suitably used as a ceiling interior material for automobiles.

Claims (5)

What is claimed is: 1. A nonwoven fabric sheet for car ceiling interior materials, comprising a nonwoven fabric made of polyester resin fibers and a polybutylene terephthalate resin laminated on at least one surface. The nonwoven fabric sheet for a car interior according to claim 1, wherein the nonwoven fabric is made of polyethylene terephthalate resin fiber. 3. The nonwoven fabric sheet for a car ceiling interior material according to claim 1, wherein the polybutylene terephthalate resin has an intrinsic viscosity of 0.6 or more. The nonwoven fabric sheet for a car interior according to claim 1 or 2, wherein the polybutylene terephthalate resin has an intrinsic viscosity in a range of 0.6 to 1.8. 3. The nonwoven fabric sheet for a car ceiling interior material according to claim 1, wherein the polybutylene terephthalate resin is a composition comprising 100 parts by weight of the polybutylene terephthalate resin and 5 to 20 parts by weight of a low-density polyethylene.