JPH05269908A - Fiber composite - Google Patents

Abstract

(57) [Summary] [Purpose] An object is to provide a fiber composite having excellent product strength and capable of achieving uniform product strength. [Structure] An inner layer formed in a state having a large number of voids by a glass fiber and a polypropylene that bonds the intersections of the glass fibers, and a thermoplastic resin that bonds the glass fibers and the pulp fibers and the intersections of the glass fibers and the pulp fibers. A fiber composite comprising a surface layer formed of a resin so as to have a large number of voids.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is mainly used for automobile interior materials,
For example, the present invention relates to a fiber composite suitably used as a ceiling core material, a door core material, or an interior material for construction.

[0002]

2. Description of the Related Art Generally, an automobile interior material is lightweight,
Materials with excellent properties such as rigidity, heat resistance, sound absorption, and moldability are required. Conventionally, as this type of material, for example, a porous fiber composite as disclosed in JP-A-64-77664 is known. That is, this fibrous composite exhibits strength by impregnating a thermoplastic resin in a mat-like material mainly composed of inorganic fibers and adhering and fixing the mutually adjacent inorganic fibers. Usually, the mat-like material used here has a large number of inorganic fibers oriented in the thickness direction by a needle punching process in order to develop strength in the thickness direction of the product. Therefore, the surface of the fiber composite is rough due to needle punching holes, local depressions, and the like.

[0003]

By the way, the interior materials for automobiles and the interior materials for construction are required to have strength enough to withstand the mounting process.

However, in the case of the above-mentioned conventional fiber composite, since the surface is formed rough due to the needle punching holes, the local depressions, etc., the variation in bending strength becomes large due to the surface roughness. As a result, the product strength is non-uniform, and there arises such a disadvantage that the product is broken at a particularly weak portion.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a fiber composite having excellent product strength and capable of achieving uniform product strength.

[0006]

The fiber composite of the present invention for solving the above-mentioned problems has an inner layer having a large number of voids formed by inorganic fibers and a thermoplastic resin that adheres at least the intersections of the inorganic fibers. Formed on both sides of the inner layer,
A surface layer having a large number of voids is formed by inorganic fibers and pulp fibers and a thermoplastic resin that adheres at least the intersections of these inorganic fibers and pulp fibers.

The internal layer is formed, for example, by melt-impregnating a mat-like material mainly composed of inorganic fibers with a thermoplastic resin, then increasing the thickness as described later, and adhering and fixing the inorganic fibers together. It

The inorganic fibers used in the present invention include, for example, glass fibers and rock wool, and the length thereof is preferably 5 to 200 mm from the viewpoint of moldability of the mat-like material. Further, as for the thickness, if the thickness becomes thin, the mechanical strength decreases, and if the thickness becomes thick, it easily breaks during mat formation.
˜30 μm is preferable, and more preferably 7 to 20 μm.

Any method may be adopted as the method for producing the mat-like material, for example, inorganic fibers are supplied to a card machine, defibrated, mixed, and needle punched to produce a mat-like material. There is a method. The needle punching treatment is preferably performed with a punch density of 30 to 100 places per cm ² .

Thermoplastic organic fibers such as polyethylene, polypropylene, saturated polyester, polyamide, and polyacrylonitrile may be added for adhering the inorganic fibers or for making the mat-like material bulky.

In the present invention, examples of the thermoplastic resin forming the inner layer include polyethylene, polypropylene, saturated polyester, polyamide, polyvinyl chloride,
Examples thereof include polyacrylonitrile.

The surface layer is obtained, for example, by placing a paper-like material composed of pulp fibers, a thermoplastic resin, a binder and the like on the surface of the mat-like material via the thermoplastic resin film for forming the inner layer. It is formed by melt impregnation and increasing the thickness as described later.

This paper-like material is manufactured by a usual papermaking method using a thermoplastic resin, pulp fibers, a binder and the like. That is, the raw material liquid in which the binder is dissolved or dispersed in water is dehydrated on a wire (mesh) to form a wet paper, and then mechanical dehydration and heating are performed to dry the paper-like material. Is obtained.

The pulp fiber is not particularly limited as long as it is used for ordinary papermaking, and various types can be used. The amount used is preferably about 2 to 20% by weight of the fiber composite of the present invention. If the amount is too small, the effect of making the surface dense and reducing the variation in strength becomes difficult to appear, and if the amount is too large, the amount of inorganic fibers decreases and the overall strength decreases.

As the thermoplastic resin added to the paper-like material, for example, polyethylene, polypropylene, saturated polyester, polyamide, vinyl chloride and the like can be used as in the thermoplastic resin impregnated in the inner layer.

As the binder, PVA (polyvinyl alcohol), CMC (carboxymethyl cellulose), HEC (hydroxymethyl cellulose) or the like can be used.

As a method for producing this fiber composite, for example, first, a thermoplastic resin film is laminated on both surfaces of the mat-like material formed mainly of inorganic fibers, and pulp fibers and a thermoplastic resin are further provided on the outside thereof. The above-mentioned paper-like materials that have been included are laminated to form a laminate.

Next, the laminate is preheated at a temperature not lower than the melting temperature of the thermoplastic resin used for this lamination and the binder in the paper-like material.

Then, the preheated laminate is pressed and compressed by a press or a roll to impregnate the resin film into the mat-like material. At this time, the pressing pressure is 0.1 to
The compression time may be 20 kg / cm ² and the compression time may be 1 to 10 seconds. Moreover, when compressing with a roll, it is preferable to set between the rolls to 5 to 20% of the material thickness. When both the press and the roll are compressed, it is preferable that they are heated to a temperature equal to or higher than the melting temperature of the resin used.

When compressed under pressure in this way, the molten thermoplastic resin and binder are impregnated in the inorganic fibers, and the pulp fibers penetrate into the inorganic fibers to some extent, and finally the surface is A layer will be formed. After that, when the pressure is released, the material tries to recover the original thickness, but the inorganic fiber is bonded to the impregnated resin, so that the material thickness is not sufficiently recovered.

Therefore, it is preferable to go through the step of expanding the material thickness (expansion step) by means such as vacuum suction from above and below.

In the present invention, the thermoplastic resin is adhered to the intersections of the inorganic fibers of the inner layer, the intersections of the inorganic fibers of the surface layer, the intersections of the inorganic fibers and the pulp fibers or the intersections of the pulp fibers, and a large number of voids are formed. have.

Such a structure is preferably obtained by the expanding step.

Finally, the fiber composite is obtained by cooling the whole while maintaining this thickness.

In the fiber composite thus obtained, the entire interior is impregnated with the thermoplastic resin, so that the intersection of the inorganic fibers constituting the mat-like material is the inner layer adhered and fixed by the thermoplastic resin. Will be configured.

Further, the mat-like material is roughened due to needle punching holes and local depressions formed on its surface by the needle-punching treatment performed in advance. By impregnating the pulp fibers and the thermoplastic resin in the particulate matter to fill this surface defect, the intersection of the inorganic fiber and the pulp fiber is adhesively fixed by the thermoplastic resin, and the surface layer whose surface roughness has been eliminated is formed. Will be configured.

The boundary between the inner layer and the surface layer in the fiber composite of the present invention may not be clearly divided.

In order to use the obtained fiber composite as an automobile interior material or a building member, the resin is melted by heating, compressed, shaped and cooled to obtain a predetermined component. At the time of compression molding, a cosmetic skin material such as vinyl chloride leather, non-woven fabric or woven fabric may be laminated and shaped.

[0029]

According to the present invention, the inner layer having a large number of voids is formed by the inorganic fiber and the thermoplastic resin that adheres at least the intersections of the inorganic fiber, and both sides of the inner layer are formed.
Since the surface layer having a large number of voids is formed by the inorganic fiber and the pulp fiber and the thermoplastic resin that bonds at least the intersections of these inorganic fiber and the pulp fiber, the surface layer is made lighter and the surface is dense due to the presence of the pulp fiber. The result is a fiber composite with no needle punching holes or local depressions.

[0030]

[Examples] Examples of the present invention and comparative examples for comparison will be shown below to clarify the reason why the present invention is excellent.

The pulp fibers in each of the examples are ordinary mechanical pulp (manufactured from crushed wood).
The recycled product used in tissue paper, toilet paper, etc. was used.

[0032]

Example 1 Glass fiber having a length of 50 mm and a diameter of 13 μm
And a polypropylene fiber with a length of 50 mm and a diameter of 10 μm
After feeding and to the card machine in a weight ratio of 3: 1 and weaving
1 cm²Needle punching at 60 points per thickness 6
mm, average weight 400 g / m ²To obtain a mat-like product.

Next, MI5 having a thickness of 120 μm is formed on both surfaces.
The high-density polyethylene film of 1 was laminated, and paper was further laminated on both sides. However, the paper used was 50 g / m ² and consisted of 70% by weight of pulp fiber, 25% by weight of polypropylene fiber and 5% by weight of polyvinyl alcohol.

Next, the whole was sandwiched between Teflon sheets, heated at 200 ° C. for 3 minutes, compressed at a pressure of 5 Kg / cm ² by a press heated to 200 ° C., and then at 200 ° C.
Keep the Teflon sheet vacuumed from both sides and keep it at 3.5.
After expanding to mm, it was cooled.

In the obtained sample, pulp fibers were introduced from both sides by about 0.3 mm, the intersections of the glass fibers and the pulp fibers were adhered by a thermoplastic resin to form a surface layer, and a thickness of 3 was obtained. An internal layer of 0.2 mm was formed. The bending strength of this sample was measured according to JIS K 72
21 was measured.

The number of measurements was 30, and the average value of the strength and the standard deviation of the variation of the strength were calculated. The results are shown in Table 1.

[0037]

Example 2 Glass fiber having a length of 50 mm and a diameter of 13 μm
And a polypropylene fiber with a length of 50 mm and a diameter of 10 μm
After feeding and to the card machine in a weight ratio of 3: 1 and weaving
1 cm²Needle punching at 60 points per thickness 6
mm, average weight 400 g / m ²To obtain a mat-like product.

Next, MI5 with a thickness of 150 μm is formed on both surfaces.
The high-density polyethylene film of 1 was laminated, and paper was further laminated on both sides. However, the paper used was 20 g / m ² and consisted of 70% by weight of pulp fiber, 25% by weight of polyethylene fiber and 5% by weight of polyvinyl alcohol.

Then, the whole is sandwiched between Teflon sheets, heated at 200 ° C. for 3 minutes, compressed at a pressure of 5 Kg / cm ² with a press heated to 200 ° C., and then at 200 ° C.
Keep the Teflon sheet vacuumed from both sides and keep it at 3.5.
After expanding to mm, it was cooled.

The obtained sample had the surface layer and the inner layer formed as in Example 1. The bending strength of this sample was measured according to JIS K7221.

The number of measurements was 30, and the average value of strength and the standard deviation of strength variation were calculated. The results are shown in Table 1.

[0042]

Example 3 Glass fiber having a length of 50 mm and a diameter of 13 μm
And a polypropylene fiber with a length of 50 mm and a diameter of 10 μm
After feeding and to the card machine in a weight ratio of 3: 1 and weaving
1 cm²Needle punching at 60 points per thickness 6
mm, average weight 400 g / m ²To obtain a mat-like product.

Next, a high density polyethylene film of MI5 having a thickness of 90 μm was laminated on both sides, and paper was further laminated on both sides. However, the paper used was 80 g / m ² and consisted of 70% by weight of pulp fiber, 25% by weight of polyethylene fiber and 5% by weight of polyvinyl alcohol.

Next, the whole is sandwiched between Teflon sheets, heated at 200 ° C. for 3 minutes, compressed at a pressure of 5 Kg / cm ² by a press heated to 200 ° C., and then at 200 ° C.
Keep the Teflon sheet vacuumed from both sides and keep it at 3.5.
After expanding to mm, it was cooled.

The obtained sample had the surface layer and the inner layer formed in the same manner as in Example 1. The bending strength of this sample was measured according to JIS K7221.

The number of measurements was 30, and the average value of the strength and the standard deviation of the variation of the strength were calculated. The results are shown in Table 1.

[0047]

Comparative Example 1 A sample was prepared in the same manner as in Example 1 except that no paper was used. The bending strength was also measured in the same manner. The results are shown in Table 1.

[0048]

[Comparative Example 2] A film laminated on both sides of a mat-like material
A sample was prepared in the same manner as in Example 1 except that the thickness was 70 μm and the paper was not used (the weight was the same except the paper). The bending strength was also measured in the same manner. The results are shown in Table 1.

[0049]

Comparative Example 3 A sample was prepared in the same manner as in Example 1 except that the mat-like material was 600 g / m ² and no paper was used (the weight was the same except for the paper). The bending strength was also measured in the same manner. The results are shown in Table 1.

[0050]

[Table 1]

[0051]

As described above, according to the present invention, since a fiber composite having a light weight and a dense surface and having no needle punching holes or local dents is obtained, variations in strength and strength caused by surface roughness can be obtained. The shortage can be eliminated, and the product can be made lighter and the product strength can be improved and the product strength can be made uniform.

Claims (1)

[Claims] 1. An inner layer having a large number of voids is formed by an inorganic fiber and a thermoplastic resin that adheres at least the intersections of the inorganic fiber, and the inorganic fiber and the pulp fiber and these inorganic fibers are formed on both sides of the inner layer. A fiber composite comprising a surface layer having a large number of voids formed by a thermoplastic resin that adheres at least intersections of pulp fibers.