JP3125281B2 - Fiber molded article having resin film on surface and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fiber molded article having a resin film on its surface (referred to as a so-called mat-shaped molded article comprising a laminate for thermoforming). The fiber molded article produced by the production method of the present invention can be used, for example, as an interior material for automobiles and the like, particularly as a molded article for ceilings which is heat-shaped along the shape of the ceiling surface in the vehicle compartment and has excellent air permeability. .

[0002]

2. Description of the Related Art Conventionally, there has been provided a fiber molded article which is lightweight and excellent in heat resistance, mechanical strength, sound absorption and heat shaping properties as a ceiling material of an automobile, and a method for producing the same. For example, (1) Japanese Patent Application Laid-Open No. Hei 5-93352 discloses that a conventional fiber molded product and a skin material laminated on the surface of the molded product have air permeability. A mat-like material (fiber aggregate) mainly composed of inorganic fibers and thermoplastic resin fibers, and a thermoplastic resin film and a thermoplastic resin fiber on the surface. There has been proposed a structure in which a heat-resistant resin layer having a high melting point is provided in order, and a method of heating them to obtain a mat-shaped molded body (fibrous molded body). (2) JP-A-64-52862 discloses that a thermoplastic resin (an organic fiber or an organic powder) acting as an adhesive and a mat-like material (fiber aggregate) made of a thermoplastic resin After heating the laminated sheet obtained by laminating the film to a temperature higher than the melting temperature of the thermoplastic resin, compressing and releasing the compression, and heating the sheet to a temperature higher than the melting temperature of the thermoplastic resin to recover the thickness of the mat-like material. And a method for producing a thermoformable composite sheet by cooling.

[0003]

[Problems to be solved by the invention]

(1) However, in the case of the manufacturing method disclosed in JP-A-5-93352, a mat-like material (fiber aggregate)
And, in order to provide a thermoplastic resin film and a heat-resistant resin layer having a higher melting point than the thermoplastic resin fiber on the surface thereof,
It is necessary to use an extra heat-resistant resin layer, which increases the manufacturing cost and product cost.

[0004] Further, since there is a heat-resistant resin layer that is not melted, the heat shapeability is poor. (2) In the case of the manufacturing method disclosed in JP-A-64-52862, the surface of the laminated sheet is formed in order to heat the laminated sheet to a temperature higher than the melting temperature of the thermoplastic resin. The resulting thermoplastic resin film melts and pinhole-shaped holes are opened. For this reason, the manufactured thermoformable composite sheet is
When it is used as a ceiling material of an automobile and has air permeability, ventilation caused by a change in atmospheric pressure causes ventilation dirt.

[0005] If the heating temperature of the laminated sheet is lowered in order to avoid the opening of pinholes during the production, a good bonding state between the inorganic fibers and the thermoplastic resin film cannot be obtained. Further, the strength of the thermoformable composite sheet after production is reduced. Further, if the thickness of the film is increased in order to avoid opening of pinhole-shaped holes, the weight increases, and a lightweight composite sheet cannot be obtained.

According to the present invention, a thermoplastic resin film having a limited flow property is laminated on the surface of a fiber assembly in which a base fiber and a low-melting resin binder are mixed, and formed into a body. In addition to being able to prevent dirt and ventilation,
It is an object of the present invention to provide a fiber molded body which is lightweight, has high strength and high rigidity and has excellent moldability without increasing production cost and product cost, and a method for producing the same.

[0007]

Means for Solving the Problems The present inventors heated a thermoplastic resin film laminated on a fiber assembly (mat-like material) to a temperature not lower than the melting point of the thermoplastic resin, thereby obtaining a base material constituting the fiber assembly. We studied to solve the cause of pinhole-shaped holes in thermoplastic resin film when joining to fiber.

As a result, the thermoplastic resin film has a higher melt flow rate at the heating temperature than the melt flow rate of the resin binder mixed and integrated with the base fiber to form the fiber aggregate, and the thermoplastic resin film easily flows at the time of heating and melting. It has been found that a pinhole-shaped hole is opened. A low-melting resin binder having a specified melting point is used as a resin binder mixed and integrated with the base fiber to form a fiber assembly, and the melt flow rate at the heating temperature of the low-melting resin binder and the resin film is specified. The present invention was completed by confirming that a fiber molded body (mat-like molded body) in which the bonding state between the material fiber and the resin film was good and in which no pinhole-shaped holes were formed in the resin film was obtained.

The method for producing a fiber molded article having a resin film on its surface according to the present invention comprises: A surface obtained by heating a resin film laminated on at least the surface side of the fiber assembly, joining the base fibers by melting and solidifying the low-melting resin binder, and joining the resin film to the surface thereof physically. In the method for producing a fiber molded article having a resin film, the melting point of the low-melting resin binder is the same as or higher than the melting point of the resin film, and the melt-flow rate (JIS-JIS) at the heating temperature of the low-melting resin binder is used. K72
10) is characterized in that the relation is larger than the melt flow rate of the resin film.

[0010] The fiber molded article having a resin fill on its surface according to the present invention is composed of a base fiber made of inorganic fiber, high melting point organic fiber or metal fiber, and a low melting point resin binder to which the base fiber is joined. The formed fiber assembly, and a resin film laminated and physically bonded to at least the surface side of the fiber assembly, and the melting point of the low melting point resin binder is the same as the melting point of the resin film. Alternatively, the resin has a high relationship, and the melt flow rate at the heating temperature of the low melting point resin binder is higher than the melt flow rate of the resin film.

The heating temperature may be higher than the softening point of the low melting point resin binder. Preferably, the resin has a melting point or higher in view of the flowability of the resin, and if the heating temperature is too high, resin deterioration or thermal decomposition occurs. The low melting point resin binder can be used at a melting point of 65 ° C. to 260 ° C., and the resin film can be used at a melting point of 65 ° C. to 260 ° C.

For example, when the melting point of the low-melting resin binder is 170 ° C., the melting point of the resin film is 110 ° C. to 17 ° C.
It is preferable to use in the range of 0 ° C. The smaller the melt flow rate (JIS-K7210) of the resin film, the better. As the test conditions, the test temperature was from the melting point of the low-melting resin binder to the melting point + 80 ° C., and the test load was 2.16.
When kgf {21.18N}, the melt flow rate is preferably 0.9 or less. Preferably, it is 0.1 or less.

For example, the melt flow rate (JIS-K7210) of the low-melting-point resin binder is set to 1.0 or more when the melt flow rate (JIS-K7210 condition 14) of the resin film is 0.05. . In addition,
The melt flow rate of the low-melting resin binder and the resin film can be variously set by changing the degree of polymerization and the molecular weight distribution.

As the low melting point resin binder, any of fiber, liquid, and powder can be used. For example, as the pre-low-melting resin binder, a resin powder that is mixed with the base fiber in advance at the time of forming the fiber assembly, and then heated and melted to bind the base fiber, a thermoplastic fiber or the like can be used. By impregnating a fiber aggregate obtained by accumulating base fibers made of inorganic fibers, high-melting organic fibers, or metal fibers, impregnating between the base fibers constituting the fiber assembly, impregnating, and then heating, the base is heated. Emulsions that bind material fibers, aqueous resins, resins containing organic solvents, and the like can be used.

In particular, a fibrous form is preferred from the viewpoint of dispersibility and ease of handling. Examples of the thermoplastic fiber include olefins such as polypropylene and polyethylene, polyesters such as polyethylene terephthalate, polyamides such as nylon 6, nylon 66, polyacrylonitrile, polyvinyl alcohol, polyvinylidene chloride, and the like.
Fibers such as cellulose can be used.

As the emulsion, for example, SB
(Styrene-butadiene resin), acrylic, PVA
(Polyvinyl alcohol), phenol emulsion,
Saturated polyester emulsion, EVA (ethylene / vinyl acetate resin) and the like. Examples of the resin powder include polyethylene powder, polypropylene powder, phenol powder and the like.

The aqueous resin is, for example, an aqueous phenol. The type of resin is preferably an olefin resin from the viewpoint of heating conditions and cost. The base fiber refers to a fiber that does not melt even when heated to a temperature at which the low-melting resin binder melts, and inorganic fibers, high-melting organic fibers, metal fibers, and the like are used. As the inorganic fiber, glass fiber, alumina fiber, carbon fiber, ceramic fiber, rock fiber and the like can be used.

As the high-melting organic fiber, the temperature at which it is heated and melted is higher than the temperature at which the low-melting resin binder melts.
High resin fiber. As the high melting point organic fibers, resin fibers such as polyester fibers, nylon fibers, aramid fibers, phenol fibers and fluorine fibers can be used.
As the resin film, the same films as those listed as the thermoplastic resin forming the thermoplastic fiber are used. A homogeneous material is preferable from the viewpoint of recycling and joining.

In the fiber aggregate formed during the production of the fiber molded body (mat molded body), it is desirable that each fiber constituting the fiber aggregate be in a good entangled and dispersed state. For this reason, for example, a card web can be laminated and subjected to needle punching or the like to form a nonwoven fabric-shaped fiber aggregate. After heating the fiber assembly and the resin film, by applying pressure in the direction of compressing the thickness, the softened resin with the low-melting-point resin binder penetrates into the gaps between the base fibers almost uniformly to every corner. The fibers can be bonded together, and the resin film can be more firmly bonded to the fiber assembly.
After releasing the pressure, the material was heated above the softening point of the low-melting resin binder, the thickness was recovered by using the spring-back function of the base fiber, the bulk was increased, and the material was cooled and held at the specified thickness. Obtain a fiber molding.

The fibrous formed body has a resin film physically bonded on its surface, that is, on both sides or one side.

[0021]

According to the fiber molded article having a resin film on its surface and the method of manufacturing the same according to the present invention, the fiber assembly prepared in advance is made of inorganic fiber, high melting point organic fiber or metal fiber prior to carrying out the manufacturing method. A base fiber comprising
A low-melting resin binder is mixed and accumulated, and the fiber assembly has a resin film laminated on at least the surface side.

The melting point of the low melting point resin binder is the same as or higher than the melting point of the resin film, and the melt flow rate at the heating temperature of the low melting point resin binder is higher than the melt flow rate of the resin film. Therefore, when the fiber assembly and the resin film laminated on at least the surface side of the fiber assembly are heated to the melting point of the low-melting resin binder or higher, the resin film becomes a low-melting resin binder contained in the fiber assembly. Melts earlier or simultaneously.

When the resin film and the low-melting-point resin binder are melted, the molten low-melting-point resin binder flows in the thickness direction and the surface direction of the fiber assembly due to the difference in the melt flow rate, and the melt of the respective base fibers is reduced. Fill gaps. However, even if the resin film is melted, the amount of the resin film flowing in the thickness direction is greatly reduced, so that a pinhole is not formed unlike the related art.

Then, by cooling the fiber assembly and the resin film, the molten portion is solidified and joined, and a resin film is formed on the surface of the fiber molded body having the resin film bonded to the surface thereof. Obtainable.

[0025]

【Example】

Example 1 Example 1 of a fiber molded article having a resin film on its surface and a method for producing the same according to the present invention will be described below. In carrying out the method for manufacturing a fiber molded body having a resin film on the surface in Example 1, a fiber assembly is prepared in advance.

The fiber assembly is composed of glass fiber (Φ10 μm × fiber length 67 mm) used as a base fiber and polypropylene fiber (denier 6 d / f × fiber length 64 mm) used as a low melting point resin binder. Fiber 300
g / m ² : polypropylene fiber mixed at a mixing ratio of 300 g / m ² , formed into a predetermined shape and size by a card machine, and a polyethylene film (thickness 150 μm) laminated as a resin film on one side. It is. The fiber assembly is in a state where glass fibers and polypropylene fibers are intricately intertwined.

Here, the fiber assembly used in the production method of Example 1 is characterized by the relationship between the melting points of the polypropylene fiber and the polyethylene film and the relationship between the melt flow rate (MFR). That is, as a polypropylene fiber, the melting point is 173 ° C. and the melt flow rate (JI
A polyethylene film having a melting point of 140 ° C. and a melt flow rate (JIS-K7210 condition 14) of 0.0 was used, with S-K7210 condition 14) set to 20.
7 has been used.

The production method of Example 1 is carried out using a fiber assembly having a polyethylene film laminated on the other surface. In this fiber assembly, when heated, first, the polyethylene film melts before the polypropylene fiber, and its part joins the glass fiber and the polypropylene fiber present in the surface region of the fiber assembly, and then the polypropylene fiber melts. The glass fibers existing in the thickness direction of the fiber assembly and the direction perpendicular to the thickness direction are joined.

That is, when the fiber assembly is heated to 190 ° C., which is higher than the melting point of polypropylene fiber at 173 ° C.,
A polyethylene film having a melting point as low as 140 ° C. melts before polypropylene fibers having a melting point as high as 173 ° C., and thereafter, the polypropylene fibers melt. However, the polyethylene film is made of melt flow rate (JI
S-K7210 condition 14) is 0.07, which is much smaller than 20 of the melt flow rate of polypropylene fiber (JIS-K7210 condition 14).
The melt flow is much slower and slower than the melt flow of the polypropylene fibers. That is, when the polyethylene film and the polypropylene fiber are in a molten state with each other,
The larger the melt flow rate is, the easier the flow is, and the smaller the melt flow rate is, the less the flow is.

Accordingly, since the polyethylene film is difficult to flow even when it is melted, the diffusion of the melt flow is slow, and the glass fiber and the polypropylene fiber in a narrow area facing the polyethylene film (an area very close to the polyethylene film) are removed. Stays secure. As a result, the flow rate of the molten and flowing stream is smaller than that of the polyethylene film, and pinholes are not generated in the polyethylene film during heating and melting.

On the other hand, when the polypropylene fiber is melted, the melt flow rate (JIS-K721)
0 condition 14) is 20 and 0.0 of the melt flow rate (JIS-K7210 condition 14) of the polyethylene film.
Since the flow is much larger than that of 07, the diffusion by the flow is fast, and the diffusion is performed over a wide area. Penetrates into every corner to enhance the bonding effect of the glass fibers.

Then, after the pressure applied to the fiber assembly is released, the fiber is heated to a temperature higher than the softening point of the polypropylene, utilizing the springback function of the glass fiber, recovering the crush by pressurization, increasing the bulk, and cooling. Maintain the specified thickness. The pressing force at this time may be 0.1 kgf / cm ² {9.8 kPa} or more to allow the resin binder to penetrate. Since it protrudes, the pressure is preferably 200 kgf / cm ² {19.6 MPa} or less. Preferably, 1 kgf / cm ² @ 98 kP
It is preferably from 50% to 50 kgf / cm ² {4.9 MPa}.

In this manner, the fiber molded body 1 shown in FIG. 1 is manufactured. The fiber molded body 1 is cooled by the cooling.
The molten polypropylene adhered to the entanglement points of the glass fibers 10 solidifies and acts as the binder 11. On the other surface 12, the polyethylene in a molten state is solidified between the laminated polyethylene film 13 and the surface 12, and acts as a binder 14.

The fiber molded article 1 obtained by the production method of Example 1 and having the polyethylene film 13 bonded to the opposite surface 12 has a structure in which the entanglement points of the glass fibers 10 can be firmly bonded by the binder 11, Also, no pinholes were formed in the polyethylene film 13. In addition, when the polyethylene film 13 is heated to a melting point of a polypropylene fiber (not shown) of the fiber assembly 1 or higher, it does not form a pinhole even if it is melted. Bonding to the fiber 10 can be ensured.

For this reason, the manufactured fiber molded body 1 can improve the strength and has no pinholes in the polyethylene film 13. In addition, the two parts of the resin film having the adhesive action and the resin layer having heat resistance do not have to be constituent parts, and the production cost and product cost do not increase.

Further, the fiber molded body 1 produced by the production method of Example 1 is heat-shaped, for example, in accordance with the shape of the ceiling surface in an automobile interior, mounted on the ceiling surface, and used as a molding material for the ceiling. In this case, since it is excellent in air permeability, it does not generate ventilation dirt. In the method of manufacturing the fiber molded body 1 of Example 1, polypropylene fiber is used as the low-melting point binder. However, the present invention is not limited to this, and liquid (emulsion) and powder can be used.

(Example 2) According to the method for producing a fiber molded article having a resin film on the surface thereof in Example 2, glass fiber (Φ10 μm × fiber length 50 mm) was used as a fiber assembly.
And polyethylene fiber (denier 6 d / f × fiber length 51 mm) used as a low-melting resin binder, glass fiber 300 g / m ² : polyethylene fiber 300 g / m ²
, And formed into a predetermined shape and size by a carding machine. A polyethylene film (thickness: 130 μm) is formed as a resin film on one surface and the other surface.
m) are laminated.

Here, the fiber assembly used in the production method of Example 2 is made up of the relationship between the melting points of the polyethylene fiber and the polyethylene film and the melt flow rate (M
FR). That is, the polyethylene fiber has a melting point of 130 ° C. and a melt flow rate (JIS-K
That is, a film having a melting point of 130 ° C. and a melt flow rate (JIS-K7210 condition 14) of 0.1 was used as the polyethylene film.

Table 1 shows the relationship between the melt flow rate and the thickness of the polyethylene film.

[0040]

[Table 1] (* JIS-K7210 condition 14) Except for the above, a fiber molded body having a resin film on the surface is manufactured in the same manner as in the manufacturing method of Example 1.

Example 3 According to the method for producing a fiber molded product having a resin film on the surface thereof in Example 3, glass fibers (Φ13 μm × fiber length 25 mm) were used as a fiber assembly.
And polypropylene fiber (denier 9 d / f x fiber length 76 mm) used as a low-melting resin binder, glass fiber 200 g / m ² : polypropylene fiber 300 g /
m ² , mixed into a predetermined shape and size by a carding machine, and a polyethylene film (thickness: 100 μm) was laminated as a resin film on the other surface.

Here, the fiber assembly used in the production method of Example 3 is characterized by the relationship between the melting points of the polypropylene fiber and the polyethylene film and the relationship between the melt flow rate (MFR). That is, as a polypropylene fiber, the melting point is 167 ° C. and the melt flow rate (JI
S-K7210 The condition 14) was set to 15 and a polyethylene film having a melting point of 135 ° C. and a melt flow rate of 0.01 was used.

Except for the above, a fiber molded body having a resin film on the surface is manufactured in the same manner as in the manufacturing method of the first embodiment. (Embodiment 4) According to the method for producing a fiber molded body having a resin film on the surface thereof in Embodiment 4, the same fiber assembly having the same structure as that shown in Embodiment 3 is used, and the other surface and the other side are used. The polyethylene film shown in Example 3 was laminated on the surface.

Except for the above, in the same manner as in the case of the manufacturing method of Example 3, as shown in FIG. 2, polyethylene films 13 and 13a laminated on one surface 12 and the other surface 12a, respectively. Fiber molded body 1 having
A is manufactured. In the fiber molded body 1A, the polypropylene in a molten state attached to the interlace points of the glass fibers 10 solidifies and acts as a binder 11. On the other surface 12 and the other surface 12a, the laminated polyethylene films 13 and 13a are solidified with polyethylene in a molten state between the one surface 12 and the other surface 12a, and the binders 14 and 14a. Acts as. For this reason, the fiber molded product 1A obtained by the production method of Example 4 is reinforced and reinforced in a sandwich shape by the laminated polyethylene films 13 and 13a.

(Embodiment 5) According to the method for manufacturing a fiber molded body having a resin film on the surface thereof in Embodiment 5, the fiber aggregate having the same structure as in Embodiment 3 is used, and the fiber aggregate is blended with a blender. This is the same as the production method of Example 3, except that a glass fiber and a polypropylene fiber are mixed and defibrated using a mixer such as a card machine or a defibrating machine.

The fiber molded product obtained in Example 5 can equalize the surface weight in the entire region in the surface direction, and can reduce the variation in the surface weight. (Embodiment 6) According to the method for producing a fiber molded body having a resin film on the surface thereof in Embodiment 6, the same structure as shown in Embodiment 3 or 5 is used as the fiber aggregate, and the fiber aggregate is used. Example 3 or Example 5 except that needle punching was performed with a needle punching machine to form a nonwoven fabric.
Is the same as the manufacturing method.

The strength of the fiber molded product obtained in Example 6 is improved because the glass fibers are also oriented in the thickness direction of the fiber molded product.

[0048]

According to the present invention, when a resin film laminated on at least one side of a fiber assembly is heated at the time of production, the fiber The low melting point resin binder contained in the body melts before or simultaneously with the resin film.

When the low-melting-point resin binder and the resin film are melted, the molten low-melting-point resin binder flows in the thickness direction and the surface direction of the fiber assembly due to the difference in the melt flow rate, and the gap between the base fibers is reduced. Fill up. However, even if the resin film is melted, the amount of the resin film flowing in the thickness direction is greatly reduced, so that a pinhole is not formed unlike the related art.

Further, since the resin film does not form pinholes even when it is melted, it can be heated to a higher temperature.
In addition, it is possible to surely join the base fiber to the base fiber.
For this reason, the manufactured fiber molded body can improve the strength,
In addition, since there is no pinhole in the resin film, in order to prevent pinholes as in the prior art, at least one side of the fiber assembly has a resin film having an adhesive action and a resin layer having heat resistance. One part does not need to be a component part, and the manufacturing cost and the product cost do not increase.

Accordingly, it can be used as an interior material for automobiles and the like, particularly a molding material for ceilings which is heat-shaped along with the shape of the ceiling surface in the passenger compartment and has excellent air-permeability, and this ceiling molding material has a temperature change. There is no ventilation caused by the above, and no ventilation contamination occurs.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a fiber molded body (mat-like molded body) obtained by the production method of Example 1.

FIG. 2 is a cross-sectional view showing a cross-section of a fiber molded product obtained by the production method of Example 4.

[Explanation of symbols]

1, 1A: Fiber molded body (mat-like molded body) 1
0: Glass fiber 11: Low melting point resin binder bound to the entanglement point of glass fiber 12: One surface 12a: The other surface 13, 13a: Polyethylene film 14, 14a: Polyethylene film bound to glass fiber

Continued on the front page (72) Inventor Masakazu Isogai 1-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Boshoku Corporation (72) Inventor Tsugumi Sannomiya 1 Toyota-cho, Toyota-shi, Aichi Prefecture Inside Toyota Motor Corporation (72 ) Inventor Masaki Fujiwara 1 Toyota Town, Toyota City, Aichi Prefecture Within Toyota Motor Corporation (56) References JP-A-1-165431 (JP, A) JP-A-5-16138 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) B32B 1/00-35/00

Claims (2)

(57) [Claims] 1. A fiber assembly obtained by mixing and integrating a base fiber made of an inorganic fiber, a high melting point organic fiber or a metal fiber and a low melting point resin binder, and a resin film laminated on at least one side of the fiber assembly. The method for producing a fibrous molded article having a resin film on the surface thereof by heating and joining the base fibers by melting and solidifying the low melting point resin binder and bonding the resin film to the surface thereof, The melting point of the melting point resin binder is the same as or higher than the melting point of the resin film, and the melt flow rate at the heating temperature of the low melting point resin binder is larger than the melt flow rate of the resin film. A method for producing a fiber molded article having a resin film on the surface. 2. A fiber assembly formed of a base fiber made of an inorganic fiber, a high-melting organic fiber, or a metal fiber, and a low-melting resin binder to which the base fibers are joined; And a resin film laminated and physically bonded to at least the surface side of the low melting point resin binder, wherein the melting point of the low melting point resin binder is in the same or higher relationship as the melting point of the resin film. A fiber molded article having a resin fill on a surface, wherein a melt flow rate at a heating temperature is larger than a melt flow rate of the resin film.