JP2976394B2 - Reinforcing material for foam molded products - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a reinforcing material for a foam molded product, and more particularly to a reinforcing material for a foam molded product capable of imparting sufficient rigidity to the foam molded product.

<Prior Art> Molded products such as polyurethane foam are used as cushioning materials for vehicle seats and the like. A reinforcing material is provided at the bottom of such a foam molded article, and the reinforcing material effectively receives a pressing force from a coil spring mounted on the bottom to impart elasticity to the sheet, and is damaged. There is no stiffness and the rigidity is maintained so that the cushioning properties can be given tension.

Conventionally, cold gauze and slab urethane have been used as such reinforcing materials. For example, a structure in which slab urethane is laminated on the bottom of a foamed polyurethane molded product via a cold gauze is used, and the cold gauze and the slab urethane are used as reinforcing materials.

However, since the conventional cold gauze and slab urethane alone cannot provide sufficient rigidity, there has been a problem that the rigidity must be reinforced by filling a wire. In the production of a foam molded article having such a reinforcing material disposed on the bottom, first, a reinforcing material is attached to a mold surface of a foam molding die, and then urethane is injected to cause foaming. At this time, the urethane is impregnated into the reinforcing material, and a foam molded article in which the foam layer obtained by foam molding and the reinforcing material are integrally joined is obtained. In this molding operation, if the rigidity of the reinforcing material is not sufficient, there is a problem that it is difficult to attach the reinforcing material to the mold surface of the mold.

Therefore, a reinforcing fabric for urethane foam molding using a nonwoven fabric having a two-layer structure of a high-weight layer and a low-weight layer has been proposed (Japanese Utility Model Publication No. 62-26193).

<Problems to be Solved by the Invention> However, a complicated operation is required to form the nonwoven fabric having the two-layer structure, and the resin material for foam molding passes through the nonwoven fabric in this reinforcing material base fabric. Therefore, it is not possible to prevent the resin liquid for foam molding, which has passed through the nonwoven fabric, from reaching the air vent holes of the mold and foaming, thereby blocking the air vent resistance. If an adhesive layer or the like is formed between the two layers in order to prevent the passage of the resin solution, the passage of air is also prevented, so that the nonwoven fabric as a reinforcing material is effectively impregnated with the resin solution. However, there was a problem that the function as a reinforcing material was reduced.

Therefore, an object of the present invention is to provide a foam molded article with sufficient rigidity, to further improve workability in a foam molding operation, and to prevent the resin liquid for foam molding from passing during foam molding and to block air vent holes. It is another object of the present invention to provide a reinforcing material for a foamed molded product that can further improve rigidity by absorbing a resin liquid without performing the method.

<Means for Solving the Problems> In order to solve the problems, the present invention provides a fiber having a fiber diameter of 1 to 20.
a base layer made of a nonwoven fabric having a basis weight of 100 to 800 g / m ² formed of the fibers of d, and a reinforcing covering material formed of a fiber aggregate or a synthetic resin formed on one surface of the base layer And a reinforcing material for a foam molded article having a layer.

Hereinafter, the reinforcing material for a foam molded product of the present invention will be described in detail.

In the reinforcing material for a foamed molded product of the present invention, the material fibers of the nonwoven fabric as the base material layer are polyamide (nylon),
Synthetic fibers such as polypropylene, polyester, high density polyethylene (HDPE), low density polyethylene (LDPE),
Regenerated cellulose fibers such as rayon, natural fibers such as cotton yarn,
Alternatively, any fiber, such as a so-called sheath-core type composite fiber, in which the core portion and the sheath portion are composed of different fibers, respectively, is not particularly limited, and one type thereof alone or a combination of two or more types may be used. It may be something.

The fiber diameter of the material fiber of this high-weight nonwoven fabric is 1 to 20 d in that a nonwoven fabric having good hardness and flexibility is obtained.
And preferably 2 to 15d. Basis weight of the high basis weight non-woven fabric, a thickness is appropriate, the impregnation amount of the urethane foam is often nonwoven obtained, in that the cushioning properties of the impregnated urethane foam becomes good, 100 to 800 g / cm ² And preferably 200 to 400 g / cm ² .

The bulk density of the high basis weight non-woven fabric, usually in terms of the impregnation amount is proper range of the urethane is 0.01~0.2g / cm ³ or so, preferably from 0.05~0.15g / cm ³ approximately .

The nonwoven fabric with a high mesh weight may be manufactured by any method, for example, any of known methods such as a spun bond method, a thermal bond method, a needle punch method, a water jet method, and a melt blown method. It may be done.

In the reinforcing material for a foam molded article of the present invention, a reinforcing covering material layer made of a fiber assembly or a synthetic resin is formed on one surface of the base material layer.

This reinforcing covering material layer may be formed of an aggregate of synthetic fibers and natural fibers, and an aggregate of at least one fiber selected from natural pulp, or may be a layer made of a synthetic resin.

The aggregate of synthetic fibers and natural fibers, and the aggregate of at least one fiber selected from natural pulp are those in which synthetic fibers or natural fibers are randomly accumulated, or natural pulp that is an aggregate of natural cellulose. And one of these aggregates or a composite of two or more of these aggregates may be used.

The synthetic fiber used is not particularly limited,
Those obtained by preventing thermoplastic resin from yarn are preferred. Examples of the thermoplastic resin include polyolefin, polyester, polyacrylonitrile, and the like. Among these, polyolefins that are polymers or copolymers of at least one selected from ethylene and α-olefins are preferable, and specific examples of the polyolefins include polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene / 1. -Butene copolymer, ethylene-4-methyl-1-pentene copolymer and the like. In particular, a crystalline polyolefin is preferable in that the pulp-like aggregate can be easily produced and the mechanical properties of the obtained pulp-like aggregate are excellent.

Examples of the method of preventing yarn include flash spinning of a solution or an emulsion.

Examples of natural fibers include cotton yarn, wool, hemp yarn, and the like.

The natural pulp is produced using a raw material containing natural cellulose as a raw material, and examples thereof include wood pulp and the like, which can be used after beating treatment.

The length of the fibers constituting the fiber aggregate is usually 1
It is about 50 mm, preferably about 2-20 mm. The fiber diameter is usually about 0.1 to 500 μm, preferably 10 to 100
It is about μm.

The bulk density of the fiber aggregate is not particularly limited, and is preferably adjusted to about 0.02 to 0.2 g / cm ³ .

In the present invention, when an aggregate of these fibers is used as a reinforcing coating material layer, the thickness of the layer is a basis weight, when formed by a wet method described below, about 1 to 100 g / m ² , preferably about 2 to 30 g / m ^2, when formed by a dry method, 1-200 g / m ² approximately, is preferably formed of about 5 to 30 g / m ^2.

In the present invention, the method for producing a reinforcing material for a foam molded article of the present invention using the fiber aggregate as the reinforcing coating material layer is not particularly limited, but, for example, the fiber aggregate is molded or prepared in advance. A method of adhering or fusing it to a nonwoven fabric as a base material layer; dispersing the synthetic fiber, natural fiber and / or natural pulp in an appropriate dispersion medium to prepare a dispersion; A method in which an integrated layer of fibers is formed by papermaking on one surface of a nonwoven fabric as a base material layer, and further subjected to heat treatment to thermally fuse the integrated layer of fibers to the surface of the nonwoven fabric (wet method); A method in which fibers, natural fibers, or pulp fibers obtained by disintegrating natural pulp are sprayed and deposited on a nonwoven fabric by air, and heat-treated to thermally fuse an integrated layer of fibers to the surface of the nonwoven fabric (dry method). And the like.

The heat treatment may be performed by any method such as a method of blowing hot air, a method of passing between heat sources, a method of infrared heating, a method of a heater or the like, and a method of a hot roll.

In the reinforcing material for a foamed molded article of the present invention, when the fiber assembly is used as a reinforcing coating material layer, if the fibers used for the fiber assembly are appropriately selected, a reinforcing coating having a desired air permeability or airflow resistance can be obtained. A material layer can be obtained. For example, as a nonwoven fabric, a polypropylene nonwoven fabric (basis weight: 200 g /
m ² , bulk density: 0.1 g / cm ³ )
The ventilation resistance of the reinforcing material made of E fiber (average fiber length: 0.8 mm) is 0.06 kPa · sec / m. Further, the ventilation resistance of the reinforcing material composed of the same nonwoven fabric and synthetic fiber (HDPE) / natural pulp: 7/3 as described above is 0.15 kPa · sec / m.

As the reinforcing covering material layer, when the fiber aggregate is formed, a preferable combination of the nonwoven fabric as the base material layer and the fiber covering as the reinforcing covering material layer has a fiber diameter of 2 to 15 d and a basis weight of 2.
00~400g / m ^2, and the nonwoven fabric bulk density 0.05~0.15g / cm ^3, average fiber length 10 to 100 [mu] m, a combination of the aggregate of synthetic fibers having a bulk density of 0.02~0.2g / cm ³ (HDPE) is No. The reinforcing material for a foamed molded product formed by such a combination can impart sufficient rigidity to the foamed molded product, the workability in attaching to a mold becomes good, and the spinning of the air vent hole can be spun,
Moreover, it is preferable in that the rigidity can be further improved by absorbing the resin liquid.

In the case where a synthetic resin layer is formed as the reinforcing coating material layer in the reinforcing material for a foam molded article of the present invention, examples of the synthetic resin include urethane resins, acrylic resins, epoxy resins, and melamine resins.

This synthetic resin layer, for example, on one side of the non-woven fabric, the coating amount of a coating solution obtained by dissolving or dispersing this synthetic resin in an appropriate solvent is about 1 to 40 g / m ² , preferably 5 to 30 g / m ²
It is formed by coating to a degree. The concentration of the synthetic resin in the coating solution is usually about 5 to 50% by weight, preferably 10 to 50% by weight.
It may be adjusted to about 30% by weight.

As the solvent used for the coating liquid, those usually used in this kind of field are used as they are.

The application of the coating solution may be performed according to a conventional method, for example, according to a method such as a spray method, a roll coater method, and a brush coating method.

The reinforcing material of the present invention can be applied to any foamed molded article, and can be applied to a foamed molded article made of urethane or the like, for example, to impart good rigidity. For example, the present invention can be applied to molding of foamed products for various uses such as automobile seats, furniture, office chairs, and beds.

Hereinafter, the reinforcing material for a foamed molded product of the present invention using the fiber assembly as a reinforcing coating material layer and a process of manufacturing a foamed molded product using the same will be described with reference to FIGS. 1 to 3.

A reinforcing material 1 for a foam molded article shown in FIG. 1 has a base layer 2 made of a high-weight nonwoven fabric and a reinforcing coating layer 3 made of a fiber assembly formed on the lower surface of the base layer 2. Things.

As shown in FIG. 2, the reinforcing material 1 for a foamed molded product is
The cavity 7 is formed by arranging the reinforcing coating material layer 3 in the mold 4 so that the mold surface 5 of the mold 4 for foam molding is in contact with the mold surface 5. At this time, since the reinforcing material 1 for a foamed molded product of the present invention has the reinforcing coating material layer 3, the rigidity is higher than that of the nonwoven fabric alone. Excellent in nature.

Next, the resin liquid for foam molding is poured into the cavity 7 formed in the mold, and heated and pressurized to foam, so that the foam molding layer 8 corresponding to the cavity 7 is formed as shown in FIG. Is done. At this time, the nonwoven fabric as the base layer 2 is impregnated with the resin liquid for foam molding, and is also foamed at the same time to form a layer 2a into which the foamed resin has penetrated into the nonwoven fabric. A foam molded article joined to the layer 8 is obtained.

As described above, a foam molded article having a reinforcing material on one side is obtained.

At this time, the resin liquid for foam molding is impregnated into the base material layer, ie, the nonwoven fabric, but does not reach the mold surface after passing through the reinforcing coating material layer. (Not shown) is not blocked. Moreover, since the reinforcing material and the foam molding layer are bonded as described above in the nonwoven fabric which is the base material layer of the reinforcing material, the rigidity can be improved.

In addition, the reinforcing material 11 for a foam molded article shown in FIG. 4 includes a base layer 12 made of a nonwoven fabric with a high weight and a reinforcing coating layer 13 made of a synthetic resin formed on the lower surface of the base layer 12. Have In the same manner as in the step shown in FIG. 2, the foam-molded product reinforcing material 11 is placed in a mold so that the reinforcing coating material layer is in contact with the mold surface of the foam-molding mold. A foam molding product can be manufactured by injecting a foam molding resin liquid into a mold, heating and pressurizing to foam.

In this way, as shown in FIG.
On one side of the base material layer 12 having a layer 12a in which the foamed resin has penetrated
And a reinforcing material having a reinforcing covering material layer 13 made of a synthetic resin
A foam molded article to which 11 is joined is obtained.

The reinforcing material 11 for a foam molded article having the structure shown in FIG. 4 and the foam molded article shown in FIG.
Similar to FIG. 3, similar effects can be obtained in improving rigidity, improving workability, preventing air vent holes from being closed, and the like.

<Effect of the Invention> Since the base material layer of the reinforcing material for a foamed molded product of the present invention is made of a nonwoven fabric with a high basis weight, the air vent hole of the molding die in the foaming molding operation is not blocked, and uniform foaming can be performed. It is possible to obtain a foam molded article having improved surface rigidity.

In addition, since the reinforcing coating material layer as described above is provided on one side of the high-grain nonwoven fabric, the impregnation of the foam molding resin liquid is stopped halfway, the degree of impregnation of the resin liquid is adjusted, and a dense foam layer is formed. It is effective for improving rigidity. Further, by improving the rigidity, the reinforcing material of the present invention facilitates the work of attaching the reinforcing material to the mold surface of the mold, and greatly improves workability. Further, even if a non-woven fabric having a low bulk density (about 0.02 to 0.05 g / cm ³ ) is used for the base layer, the workability does not decrease. Further, by using the reinforcing material of the present invention, it has become possible to simplify the work conventionally required for low rigidity, for example,
In the case of an automobile seat, the number of wires used for imparting rigidity can be reduced, which is effective for simplifying the work of attaching the wires.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view for explaining one embodiment of a reinforcing material for a foam molded article of the present invention. FIG. 2 and FIG. 3 are views for explaining a method of manufacturing a foam molded article using the reinforcing material for a foam molded article shown in FIG. FIG. 4 is a schematic cross-sectional view illustrating another embodiment of the reinforcing material for a foam molded article of the present invention. FIG. 5 is a view for explaining a foam molded article manufactured using the reinforcing material for a foam molded article shown in FIG. DESCRIPTION OF REFERENCE NUMBERS 1, 11 ... reinforcing material for foam molded article, 2, 12 ... base material layer, 3, 13 ... reinforcing coating material layer, 4 ... mold, 5 ... mold surface of mold

Continuation of the front page (56) References JP-A-2-47349 (JP, A) JP-A 1-299009 (JP, A) JP-A-63-189757 (JP, U) (58) Fields investigated (Int) .Cl. ⁶ , DB name) B29C 39/00-39/44 B32B 1/00-35/00

Claims (3)

(57) [Claims] 1. A base layer made of a nonwoven fabric having a basis weight of 100 to 800 g / m ² , formed of fibers having a fiber diameter of 1 to 20 d, and a fiber accumulation formed on one surface of the base layer. A reinforcing material for a foam molded article having a reinforcing coating material layer made of a body or a synthetic resin. 2. The foamed molded article according to claim 1, wherein the reinforcing covering material layer comprises an aggregate of synthetic fibers and natural fibers, and an aggregate of at least one fiber selected from natural pulp. Reinforcement. 3. The reinforcing material for a foam molded article according to claim 1, wherein the reinforcing coating material layer is made of a synthetic resin.