JP3121699B2 - Fiber composite - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interior material having excellent heat moldability, and more particularly to a fiber composite suitably used as a ceiling material for automobiles.

[0002]

2. Description of the Related Art In general, automobile ceiling materials are required to be lightweight and have excellent properties such as rigidity, heat resistance, moldability, dimensional stability, and recyclability. 2. Description of the Related Art Conventionally, as a ceiling material for automobiles, for example, as described in Japanese Patent Publication No. 3-52342, a resin-reinforced sheet having a thermoplastic resin foam as a core material and a composite of a thermoplastic resin and inorganic fibers is used as a surface material. And the like are preferably used. This laminate is obtained by laminating a resin-reinforced sheet obtained by impregnating an organic fiber nonwoven fabric with a styrene-based emulsion in which inorganic fibers are dispersed, on both sides of a polystyrene-based resin foam sheet, and has characteristics of light weight and high rigidity. And it was also recyclable.

The above-mentioned laminate is manufactured by a method in which a pre-expanded bead of a polystyrene resin is formed into a foamed sheet using an extrusion foaming method or an in-mold foaming method, and a resin-reinforced sheet is adhered to both surfaces of the foamed sheet. I was

[0004]

However, the above laminate has a disadvantage that the strength of the laminate is slightly inferior because the thermoplastic resin foam of the core material is formed of a uniform high foam.
In some cases, the strength of the laminate in the lateral direction has been required for some applications .

[0005] The fiber composite of the present invention has been made in view of the above problems, and is lightweight and has relatively high lateral strength.
It is an object of the present invention to provide a held fiber composite.

[0008]

Means for Solving the Problems The fiber composite of the present invention comprises:
A core material is made of a thermoplastic resin foam sheet, and a surface material is a fiber composite made of a composite sheet of a thermoplastic resin and an inorganic fiber, wherein the core material is arranged in a wave-like or mesh-like shape.
Foamed thermoplastic resin strands formed by foaming
Also, the high density part with relatively low foaming is the low density part with relatively high foaming
Thermoplastic resin foam sheet formed continuously inside
It is characterized by consisting of .

As the composite sheet used in the fiber composite of the present invention, it is preferable to use a fiber reinforced sheet in which glass fibers spread into monofilaments are dispersed in a thermoplastic resin. Use of such a fiber reinforced sheet has versatility and heat moldability, heat-resistant dimensional stability,
Bending strength and the like can be improved. Examples of the thermoplastic resin include polystyrene, polyethylene, polypropylene, polybutene, nylon, polyester, vinyl polyacetate, and the like. It is preferable to use a polyolefin-based resin in view of its moldability, temperature, price, and the like. As creating a composite sheet, for example, is a suitable commercial glass paper ^{(10g / m 2 ~75g / m} 2 is a thin non-woven fabric obtained the following short fibers 25mm in principal with the so-called paper-making method by weight ), A thermoplastic resin film is laminated, heated to a temperature (melting temperature region) equal to or higher than the melting point of the thermoplastic resin, and then compressed and composited by a press or a roll. The thickness of the thermoplastic resin film is preferably about 50 to 150 μm from the viewpoint of lightness.

Further, as the composite sheet, various glass fiber nonwoven fabrics can be used instead of the glass paper in the above-mentioned production method. For example, a glass fiber nonwoven fabric in which opened fiber is entangled with a mechanical method such as a needle punching method, a chopped strand mat in which cut rovings are bound with a special binder, or a continuous strand made by continuous roving Mats and surfacing mats can be used.

The content of the inorganic fibers in the composite sheet is preferably from 1 to 40 parts by weight, and more preferably from 15 to 30 parts by weight, based on 100 parts by weight of the resin component. Desirable.

As the thermoplastic resin used for the core material, a thermoplastic resin such as polyethylene, polypropylene, and polystyrene is preferably used. As the core material, a thermal decomposition type foaming agent is used in an amount of 1 to 100 parts by weight of the thermoplastic resin.
30 parts, preferably 5 to 15 parts, are kneaded and foamed. In addition, if necessary, inorganic fibers may be added in an amount of
Parts, preferably 15 to 30 parts, an antioxidant, a heat stabilizer,
Additives such as plasticizers and nucleating agents can also be added. As the inorganic fiber, commercially available glass fiber is crushed and the fiber length is 1 mm.
The following milled fibers are suitable, but chopped strands obtained by cutting glass fibers to 1 to 10 mm can also be added.

Examples of the pyrolytic foaming agent include azodicarbonamide, azobisisobutyronitrile, N, N'-dinitrosopentamethylenetetramine, pp'-oxybisbenzenesulfonyl humanazimide, barium azodicarboxylate, Trihydrazinotriazine and the like can be used.

If the gel fraction is not high (insoluble matter is not generated even when immersed in a solvent for a long time), foaming can be stabilized by adding a crosslinking agent such as a peroxide. . As the peroxide to be used, a dialkyl peroxide having a relatively high decomposition temperature and being chemically stable is preferable. For example,
Ditertiary butyl peroxide, 2,5 dimethyl 2,5 ditertiary butyl peroxyhexyne-3. It is also useful to add an unsaturated acid such as maleic anhydride to make the foaming reaction mild or to make the resin have glass fiber adhesion.

The total weight of the fiber composite is desirably less than 600 g / m ² from the viewpoint of light weight required for applications such as ceiling materials for automobiles. Therefore, the weight of the composite sheet of the surface material is 200 g / m ^2. less than m ^2, preferably less than 120 g / m ^2, the weight of the core material is preferably a ^{200g / m 2 ~400g / m 2} . The weight ratio between the composite sheet of the surface material and the core material is preferably in the range of 1: 1 to 4. The specific gravity of the fiber composite is preferably from 0.2 to 0.7. Also, as the thickness of the core foam, it is not preferable that the thickness is too thin from the viewpoint of rigidity, and it is preferable to set the thickness between 2 mm and 5 mm. This thickness corresponds to a range of 5 to 15 times the expansion ratio.

Further, in order to shape the fiber composite, it is sufficient to reheat the resin to a temperature higher than the melting temperature of the resin and to perform cold pressing. What is necessary is just to laminate | stack and form cosmetic skin materials, such as a vinyl chloride leather and a nonwoven fabric.

In the fiber composite of the present invention, the method of arranging the expandable thermoplastic resin strands is as follows.
In order to increase the degree of efficiency,
Arrange the strands.

In order to arrange the foamable thermoplastic resin strands in a pattern such as a corrugated shape or a mesh shape, a separating comb for separating the strands extruded from the strand die is provided between the strand die and the composite sheet, and a cam or the like is provided. Thus, it can be performed by a method such as giving a regular periodic motion to the separation comb. If all the separation combs are reciprocated synchronously, the foamable thermoplastic resin strands can be arranged in a wavy pattern on the composite sheet. For example, the expandable thermoplastic resin strands can be arranged in a mesh pattern on the composite sheet.

Next , an example of the method for producing the fiber composite of the present invention will be described. After kneading the above-mentioned compound for the core material with an extruder set at a temperature not higher than the decomposition temperature of the foaming agent, a foamable thermoplastic resin strand having a diameter of 2 mm is extruded from a strand die. This strand is then combined with the composite
After being arranged on the sheet, the composite sheet is further laminated thereon. Next, this laminate is set between hot plates having a gap set to about 3 to 5 mm and left until foaming starts, foaming starts, the strands expand laterally, gaps between the strands are eliminated, and the strands melt. After confirming that they are bonded together, quickly remove them from the hot plate and quench. As the set temperature of the hot platen, the temperature is calculated from the decomposition temperature of the foaming agent to the decomposition temperature +
It is desirable to set the temperature to 20 ° C. Decomposition temperature 20
If the temperature exceeds 100 ° C. or more, the structure after foaming is disturbed by rapid foaming, which is not desirable.

FIGS. 1 and 2 are views for explaining an example of a method for producing a fiber composite according to the present invention . FIG. 1 shows that a large number of expandable thermoplastic resin strands are laminated in a corrugated pattern on a composite sheet. FIG. 2 is a plan view showing a state in which foamable thermoplastic resin strands are stacked in a mesh pattern on a composite sheet. FIG. 1 and FIG.
In 2, reference numeral 10 denotes a composite sheet, 11 denotes an expandable thermoplastic resin strand, and 12 denotes a separation comb for separating the strand 11. In FIG. 1, the strands 11 are arranged in a waveform pattern, and in FIG. 2, the strands 11 are arranged in a mesh pattern. The composite sheet 10 is transported in the direction of arrow X, and the separation comb 12 is provided between a strand die (not shown) and the composite sheet 10 to be transported, and the arrow Y
Reciprocating in the direction.

A plurality of expandable thermoplastic resin strands 11 are extruded downward from a strand die, and are placed and laminated on the composite sheet 10 being conveyed, and are extruded downward by reciprocating the separating comb 12. A periodic force is applied to the strand 11. It is performed by synchronizing the reciprocating, FIG
As shown in FIG. 1 , the strands 11 are arranged on the composite sheet 10 in a wavy pattern. If the reciprocation is delayed by a half cycle, as shown in FIG.
It is arranged in a mesh pattern on 0. Next, the composite sheet is further laminated on the strand 11 thus laminated on the composite sheet 10 .

FIG . 3 is a front view of an example of an apparatus for producing a fiber composite which can be used in the method for producing a fiber composite of the present invention . Reference numeral 20 denotes an extruder, 21 denotes a strand die provided at the tip of the extruder 20, and 22 denotes a foamable thermoplastic resin strand extruded downward from the strand die 21. Reference numerals 23 and 24 denote composite sheets of a thermoplastic resin and inorganic fibers, which are wound in rolls around feeding portions 25 and 26, respectively. Reference numerals 27 and 28 denote endless conveyor belts provided below and above, respectively, which are driven in the directions of the arrows. 30 and 31 are thickness-regulated hot plates, 32 is a cooling plate,
The laminated body conveyed while being sandwiched between the transfer belt conveyors 27 and 28 is heated and foamed while the thickness is regulated by the thickness-regulating hot plates 30 and 31 and the cooling plate 32 and cooled.
In addition, 35 is a press roll.

The extruder 20 extrudes the expandable thermoplastic resin strand 22 from the strand die 21, and the composite sheet 23, which is one of the surface materials, is fed from the feeder 25.
Laminate on top. The strands 22 stacked on the composite sheet 23 are transported while being pressed by the pressing roll 35, and the composite sheet 24 serving as the other surface material fed from the feeding section 26 is stacked thereon. A laminate in which the strands 22 are laminated between the composite sheets 23 and 24 is transferred to a transfer belt conveyor 27 or 2.
While being conveyed while being pinched and continuously transferred at 8, the thickness-regulating hot plates 30 and 31 are heated while the overall thickness is regulated. By this heating, the foamable thermoplastic resin strand 22 foams, and a core made of a thermoplastic resin foam sheet is formed. Next, it is cooled by the cooling plate 32 and continuously taken out. Thereby, a fiber composite in which the composite sheet is laminated on both surfaces of the core material of the thermoplastic resin foam sheet is continuously manufactured in a single step. In addition, if a separating comb for separating the strand extruded from the strand die is provided between the strand die and the composite sheet and a regular periodic motion is given to the separating comb by a cam or the like, the foaming thermoplastic resin can be used. The strands can be arranged on the composite sheet in a corrugated or mesh-like pattern.

[0028]

In the fiber composite of the present invention , the core material is made of a foamed thermoplastic resin sheet formed by foaming a plurality of foamable thermoplastic resin strands arranged in a wave-like or mesh-like manner. Are formed in a zigzag pattern, thereby relatively maintaining the lateral strength of the fiber composite.

[0031]

Next, examples of the fiber composite of the present invention and comparative examples of conventional fiber composites will be described.

Example 1 is an example of a fiber composite made of a thermoplastic resin foam sheet formed by foaming a strand in which a core material is arranged in a corrugated pattern, and Example 2 is an example in which the core material has a mesh shape. It is an example of a fiber composite comprising a thermoplastic resin foam sheet formed by foaming strands arranged in a pattern.

Example 1 Glass Paper (45 g / m ² ) (FVP manufactured by Olivet Co., Ltd.)
-045) on the high-density polyethylene resin film (8
6 g / m ² and a thickness of 90 μm) were laminated and compressed with a hot plate heated to a temperature of 200 ° C. at a pressure of 30 kg / cm ² . Thereafter, the whole was cooled to prepare a composite sheet. 5 parts of azodicarbonamide are blended with 100 parts by weight of a high density polyethylene resin having a melt index of 20, and 50 m
m, and was extruded downward from a strand die at a temperature of 150 ° C. from a strand die at intervals of approximately 8 mm in the width direction. Next, separation combs for separating the strands one by one were installed, and the separation combs were caused to reciprocate periodically by synchronizing each one. The amplitude of the periodic motion was approximately 8 mm, and the period was 3 seconds. Next, the above-mentioned composite sheet was moved under the strand die at a speed of 32 cm / min. The strands laminated on the composite sheet having undergone this operation had a waveform pattern as shown in FIG. 1, and had a sinusoidal waveform having an amplitude of about 8 mm and a wavelength of about 16 mm. Then, after further stacking the composite sheet thereon, the whole is a thin stainless steel box having a thickness of 1 mm (length and width, inner dimensions 250 × 250 mm, thickness 3 mm, thickness can be arbitrarily changed, airtightness of the side surface is Without foaming during the foaming), the box was sandwiched between hot plates heated to 220 ° C. Then, after confirming that the strand started foaming after about 2 minutes, the thickness of the box was reduced from 3 mm to 5 mm.
mm, and the whole was taken out after about 2 minutes and 30 seconds, was sandwiched between water-cooled cooling presses, and after cooling, the fiber composite was taken out. The obtained fiber composite had a thickness of about 4.5 mm, the adhesion between the composite sheet of the surface material and the core material formed from the strands was complete, and it could be called a sandwich structure. (Specific gravity: about 0.55) A sample having a size of 50 mm × 150 mm was cut out from the fiber composite, the bending strength and the bending elastic modulus were measured, and an average value of five measurements was obtained. The direction of the sample is set such that the traveling direction of the wave (X direction) is vertical. Table 1 shows the results.

Example 2 Example 1 was carried out in the same manner as in Example 1 except that the reciprocating periodic motion of the adjacent separating combs was delayed by half a cycle. At this time, the pattern of the strand is as shown in FIG.
It had a mesh-like pattern.

[0039]

[Table 1]

As a result, in both the first embodiment of the waveform pattern and the second embodiment of the mesh pattern , as shown in Table 1.
In addition, the bending strength and the flexural modulus in the transverse direction were slightly lower than those in the longitudinal direction.

[0041]

According to the fiber composite of the present invention , the core material is made of a foamed thermoplastic resin sheet formed by foaming a plurality of foamable thermoplastic resin strands arranged in a wavy or mesh pattern. The density portion is formed in a zigzag shape, whereby the strength in the lateral direction of the fiber composite can be improved, and a fiber composite having light weight and relatively high lateral strength can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a fiber composite of the present invention;
Are stacked in a corrugated pattern on the composite sheet.
FIG.

FIG. 2 is an explanatory view of a fiber composite of the present invention, wherein
Is stacked in a mesh pattern on the composite sheet
FIG.

FIG. 3 is suitable for use in the method for producing a fiber composite of the present invention .
The front view of an example of the manufacturing apparatus of a fiber composite .

[Explanation of symbols]

 11, 22 Strand 10, 23, 24 Composite sheet 12 Separating comb 21 Strand die 27, 28 Transfer belt conveyor 30, 31, Thickness regulation hot platen 32 Cooling plate

Claims (1)

(57) [Claims] 1. A fiber composite comprising a core material comprising a thermoplastic resin foam sheet and a surface material comprising a composite sheet of a thermoplastic resin and inorganic fibers, wherein the core material has a wavy or mesh-like shape.
From multiple foamable thermoplastic resin strands
Relatively low foaming high density part formed by foaming is relatively high
Thermoplastic formed continuously in low density part of foam
A fiber composite comprising a resin foam sheet .