JPH0762306B2 - Thermoformable composite sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a composite sheet having excellent thermoformability, particularly to a composite sheet suitably used as a ceiling material for automobiles.

[Conventional technology]

Conventionally, cardboard, glass fiber reinforced thermosetting resin sheet, etc. have been used as the base material of molded ceiling material, which is one of the interior materials of automobiles, but cardboard has poor heat shaping properties and no sound absorption. Also, since it is hygroscopic, it has a drawback that it absorbs moisture and becomes heavy when used for a long time, and the thermosetting resin sheet has low sheet productivity,
It had the drawbacks of poor heat shaping and being heavy.

Various proposals have been made to solve these drawbacks. For example, Japanese Utility Model Publication No. 58-15035 discloses a laminated pair in which a glass fiber reinforced thermoplastic resin film is laminated on both sides of a styrene resin foam sheet. An automobile interior material in which a soft synthetic resin foam and vinyl chloride leather are sequentially laminated on one surface is described.

The interior material has excellent heat resistance and mechanical strength,
It was relatively heavy, had no sound absorption, was expensive, and still lacked heat shaping properties. Japanese Unexamined Patent Publication (Kokai) No. 60-83832 describes an automobile ceiling material in which a foam layer and a skin are laminated on a resin layer on a base material in which a thermoplastic resin layer is laminated on both sides of a glass fiber layer.

The base material is thin and has high mechanical strength and excellent heat formability, but it does not have sound absorbing properties, heat insulating properties, etc., and it is necessary to laminate a foam layer as an automobile ceiling material, and as a whole, Has poor heat shapeability.

[Problems to be Solved by the Present Invention]

In view of the above drawbacks, the present invention has excellent heat resistance, mechanical strength, sound absorption, heat shaping properties, and the like, is lightweight, has high productivity, is low in cost, and can be suitably used as a ceiling material for automobiles. The purpose is to provide.

[Means for solving problems]

The mat-like material used in the present invention is made of glass fiber, and the length of the glass fiber is 5 from the viewpoint of forming the mat-like material.
˜200 mm is preferable, and it is more preferable that the content of 50 mm or more is 70% by weight or more. Further, the thickness is preferably 2 to 50 μm, more preferably 7 to 20 μm because the mechanical strength decreases as the thickness becomes thinner and the bulk density becomes smaller as the thickness increases.

When the density of the mat-like material increases, it becomes heavier, and when it decreases, the mechanical strength decreases, so that it is preferably 0.01 to 0.2 g / cm ³ , and more preferably 0.03 to 0.07 g / cm ³ .

Any method may be adopted as the method for producing the mat-like material, and for example, there is a method for producing a mat-like material by supplying glass fiber to a card machine.

The thermoplastic resin binder used in the present invention may be one that can bind glass fibers to each other and that can adhere to the thermoplastic resin film, such as polyethylene, polypropylene, polystyrene, saturated polyester, polyamide, etc. Can be given.

The thermoplastic resin binder can be used in any form, and examples thereof include powder, pellets, fibers, emulsions and suspensions.

Any method may be adopted as the method of forming the columnar reinforcing portion with the thermoplastic resin binder. For example, in the case of powder, pellets, fibers, etc., it is placed on the portion to be reinforced, vibrated and dropped to the lower part. There is a method of needle-punching and then heating to integrally bond them. In the case of emulsion, suspension, etc., they may be supplied to the portion to be reinforced and impregnated and then dried.

When the addition amount of the thermoplastic resin binder is small, the reinforcing effect is lost, and when the addition amount is large, the amount becomes heavy, so 50 g / m ² to 50
It is preferably added at 0 g / m ² . The shape of the reinforcing portion viewed from the side of the thermoplastic film may be appropriately tested, and examples thereof include a dot shape, a linear shape, a curved shape, a lattice shape, a hexagonal shape (honeycomb shape), and a ring shape.

Examples of the thermoplastic film used in the present invention include films of thermoplastic resins such as polyethylene, polypropylene, polystyrene, saturated polyester and polyamide.

The thickness of the thermoplastic resin film is preferably 20 to 300 μm, more preferably 50 to 200 μm, since the mechanical strength decreases as the thickness decreases and the thickness increases as the thickness increases.

Any method may be adopted as the method for laminating the thermoplastic resin film, and examples thereof include a method of heating on a mat-like material and then heat-bonding by pressurizing if necessary, a method of extrusion laminating on the mat-like material, and the like. To be

Since at least one of the thermoplastic resin film and the reinforcing portion need to be adhered, the thermoplastic resin film is laminated on the mat-like material in which the thermoplastic resin binder is dispersed, and heating is performed if necessary. The shape of the reinforcing part, a method of simultaneously adhering the reinforcing part and the thermoplastic resin film, and extruding and laminating the thermoplastic resin on both sides of the mat-shaped object on which the reinforcing part is formed and pressing the thermoplastic film to form the mat-shaped object. Examples of such a method include a method of stacking the same on a substrate and adhering it to the reinforcing portion.

Further, a large number of through holes may be provided in the thermoplastic resin film in order to improve the sound absorbing property.

The thermoformable composite sheet of the present invention can be easily shaped by heating and pressing. Further, a foamed sheet or a skin material for makeup may be laminated and shaped.

〔Example〕

 Next, examples of the present invention will be described.

Example 1 Glass fibers having a length of 50 to 100 mm and a diameter of 10 μm were supplied to a card machine to obtain 400 g / m ² of glass fiber mat.
Polyethylene powder (melting point 135
℃, diameter 100-200μm) 100g / m at 10cm intervals both vertically and horizontally
² is placed is fed to 200 ° C. dryer after needle punching (100 points / m ²⁾ at a felt needle 1 mm in diameter, to bond the glass fibers with polyethylene powder was heated for 3 minutes to create a reinforcing part did. Next, polyethylene (melting point 135 ° C) is extrusion-laminated at 150 g / m ^{2 on} both sides of the mat-like material on which the reinforcing part is formed, pressed through a roll with a clearance of 10 mm, and has a thickness of 10 mm and a weight of 800 g / m ² A thermoformable composite sheet of was obtained.

The obtained composite sheet (length 1400mm, width 1150mm) is 200 ℃
After heating for 2 minutes with a dryer, supply it to a mold at 30 ° C, 1kg /
Compression molding was performed at a pressure of cm ² to obtain a molded body. The mold had a minimum thickness part of 3.0 mm and a maximum thickness part of 8.0 mm, and the obtained molded product was shaped according to the shape of the mold and had good heat shaping properties. The obtained molded product was heated in a hot air dryer at 95 ° C for 20
After keeping horizontal for a time, the amount of displacement (dripping) was measured. or,
A sample with a thickness of 6 mm, a width of 100 mm, and a length of 150 mm is created from the molded body, placed on a pair of supports placed 100 mm wide, and a load is applied to the center of the sample at a speed of 50 mm / min. The bending weight of the sample was measured (flexural strength). Also, the thickness is 8m from the molded body.
A sample with m, a width of 500 mm and a length of 500 mm was prepared, and the sound absorption coefficient at 500 Hg was measured by the normal incident sound absorption coefficient measuring method. The results are shown in Table 1.

Example 2 The same as Example 1 except that polyethylene powder was placed in a continuous regular hexagon (honeycomb shape) having a side of 5 cm and needle punched (about 170 points / m ² ) at both ends and the center of each side. A thermoformable composite sheet was obtained, and then a molded body was obtained, and the displacement amount, bending strength and sound absorption coefficient were measured, and the results are shown in Table 1. The molded body was shaped according to the shape of the mold, and was heat-formed well.

Comparative example Glass fiber with a length of 50 to 100 mm and a diameter of 10 μm and a length of 50 to 100
1: 1 mm polyethylene fiber with a diameter of 13 μm (melting point: 135 ° C)
(Weight ratio) is supplied to the card machine and mixed to obtain a mat-like material, then 100 points / m ² needle haunch is performed, then heated in a dryer at 200 ° C for 3 minutes to obtain a thickness. A composite sheet having a size of 10 mm and a weight of 800 g / m ² was obtained.

Using the obtained composite sheet, a molded body was obtained in the same manner as in Example 1, and the displacement amount, bending strength and sound absorption coefficient were measured, and the results are shown in Table 1. In addition, the molded body was shaped corresponding to the shape of the mold, and the heat shaping property was good.

[Effect of the invention] The constitution of the thermoformable composite sheet of the present invention is as described above, and since the thermoformability is excellent, it can be easily shaped by heating and pressing. Is heat resistant,
It has excellent mechanical strength, sound absorption, etc., is lightweight, and is low in cost, so it can be suitably used as a molded ceiling material for automobiles, a building material, and a packaging material for electronic equipment.

Claims (1)

[Claims] 1. A thermoplastic resin film laminated on both sides of a glass fiber mat-like material, and a glass between a part of one thermoplastic resin film and a part of the other thermoplastic resin film corresponding to the thermoplastic resin film. A thermoformable composite sheet characterized in that a substantially columnar reinforcing portion is formed by integrally binding fibers with a thermoplastic resin binder, and the reinforcing portion is bonded to at least one of the thermoplastic resin films. .