JP2988969B2 - Method for producing fiber-reinforced foamed phenol molding - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a fiber-reinforced foamed phenol molded article suitably used as an interior material for automobiles, furniture, interior and exterior materials for buildings, and the like.

[Prior art] In automotive interior materials, furniture, interior and exterior materials for construction, etc.,
Light weight, flame retardancy, soundproofing, heat insulation, workability, strength equal to or higher than a predetermined level are required. Molding materials that may meet these various physical properties include fiber reinforced foamed phenolic moldings.

Examples of the conventional fiber-reinforced foamed phenol molded article include a foamed thermosetting resin foam body, and a foamed resin substrate to which non-sublime fibers are added or coated.

However, conventional fiber-reinforced foamed phenolic molded articles composed of thermosetting resin foams have poor elasticity, and are easily crushed particularly by local stress, and are hardened from the surface against scratching and rubbing. Has the major drawback that it becomes powder and drops. It is unsuitable to use materials having such disadvantages for automobile interior materials, furniture, interior and exterior materials for construction, etc., which adversely affects the mental or physical health of the users inside them. .

On the other hand, simply applying non-sublime fibers to the foamed resin and applying the resin to the foamed resin does not sufficiently permeate the resin between the fibers. For this reason, after foaming, the resin layer and the fiber layer are clearly separated, and a sister or a portion where there is no entanglement of fibers occurs when the fiber layer is a multilayer. When the stress applied to such a material, in particular, bending and peeling, acts on the foamed layer (not reinforced by the fiber and is weak in strength), the material is not reinforced by the fiber, so that it is extremely broken. easy. Therefore, there is a problem that the strength of the entire material is reduced.

JP-A-62-148217, JP-A-63-30514,
Japanese Patent Application Laid-Open No. 64-5824 discloses techniques relating to a phenolic resin molded product. However, these techniques do not solve the above-mentioned problems because the mixing uniformity of the resin and the fiber is incomplete.

[Problems to be Solved by the Invention] Accordingly, the present invention addresses the above-mentioned problems of the prior art and has flame retardancy as an automobile interior material, furniture, interior and exterior materials for buildings, and can be suitably used. It is an object of the present invention to provide a method for producing a fiber-reinforced foamed phenol molded product in which the resin and the fiber are not separated or peeled as described above.

[Means for Solving the Problem] The method for producing a fiber-reinforced foamed phenolic molded article of the present invention is characterized in that a mixing ratio of a phenolic resin containing a foaming agent to a thermoplastic foamed resin is 100 parts by weight of phenolic resin. A step of mixing the plastic foaming resin so as to be 3 to 30 parts by weight and spraying the mixture on the upper surface of the noble fiber; and a step of applying vibration to the fiber sprayed with the mixture so as to uniformly penetrate the fiber into the fiber. Heating the mixture and the fibers to perform primary heating in a felt shape, and a temperature and time for the thermoplastic foamed resin to foam the felt-like molded product by the primary heating and to prevent cells from being roughened due to abnormal foaming. The thermoplastic foamed resin and the phenolic resin containing a foaming agent that have entered between the fibers are expanded by heating and pressing at The phenolic resin is characterized by comprising a step of filling between no gap fibers.

In the practice of the present invention, the phenolic resin is preferably a novolak-type or cresol-type phenol resin to which a usual curing agent such as hexamine is added.

In order to foam the phenol resin, it is preferable to use a thermoplastic foaming resin, and to use a usual foaming agent such as sodium hydrogen carbonate, ammonium carbonate, dinitrosopentamethylenetetramine or the like as an auxiliary.

It is preferable that the felt-like material is primarily heated before the step of further heating and pressing. This is because the primary heating greatly facilitates handling of the felt-like material.

In addition, as a sublime fiber, a chemical fiber, a natural fiber, an inorganic fiber, or the like can be used.

[Function] According to the present invention having the above-described structure, the fibers are uniformly distributed throughout the molded product, so that the strength is greatly improved, and there is no possibility that fragile portions are scattered. In the present invention, since a noble material is used as the reinforcing fiber, the foamed resin is sufficiently dispersed in each fiber, and even if the fiber layers are multilayered, the fibers between the fiber layers come into contact with each other. Some confounding. Therefore, there is no possibility that the fibers are cut off and completely separated. Then, when the resin foams, a uniform foaming resin is filled between the fibers, so that the composition of the molded article is homogenized and partially weak portions are eliminated. As a result, the physical properties of the molded product, particularly the bending and peeling strength, are remarkably improved, and a lightweight and durable molded product can be obtained.

Moreover, since the main foaming agent of the molded article produced by the present invention is a thermoplastic foamed resin, the foamed cells become uniform, and the foam molded article is given elasticity. And
Since the mixing ratio is 3 to 30 parts by weight of the thermoplastic foamed resin with respect to 100 parts by weight of the phenol resin, the flame retardancy of the phenol resin is maintained, and the molded product also has the flame retardancy. In addition, simply mixing a foaming agent into the phenolic resin,
After foaming, the surface of the molded article becomes very brittle, resulting in a so-called "ragged state". However, according to the production method of the present invention having the above mixing ratio, since the thermoplastic foamed resin acts as a binder, the molded product is homogenized, and powder dripping from the surface of the foamed molded product, which is a major drawback in the prior art. Fall is prevented.

As described above, according to the production method of the present invention, a molded article having various characteristics such as light weight, flame retardancy, soundproofing, heat insulation, workability, and strength can be obtained, and automobile interior materials, furniture, It is suitably used for building interior and exterior materials.

In addition to this, according to the production method of the present invention, a plurality of types of foaming agents are contained in the molded product, whereby the range of foam molding conditions is widened, and a fiber-reinforced foamed phenol molded product having various properties is provided. It will be.

[Example] Hereinafter, an example of the present invention will be described.

First, various steps in the manufacturing method of the present invention will be described with reference to the drawings.

First, as shown in FIG.
Lay. Then, as shown in FIG. 2, a mixture 2 in which a foaming agent and a thermoplastic foamed resin are mixed in a phenol resin is sprinkled on the fiber 1 in an appropriate amount.

Here, the composition of the mixture 2 is such that the foaming agent is 3 to 10 parts by weight, the thermoplastic foamed resin is 3 to 30 parts by weight with respect to 100 parts by weight of the phenol resin.
It is preferred to mix parts by weight. It is preferred that the blowing agent is mixed in an amount of 3 to 10 parts by weight. If the amount of the foaming agent is 3 to 10 parts by weight, a molded product can be obtained in good balance with the thermoplastic foamed resin. Also, when the amount of the thermoplastic foamed resin is small, the molded product becomes ragged, and when the amount is large, flame retardancy cannot be obtained.

Subsequently, when a vibration is applied to the table T, the mixture 2 penetrates into the fiber 1 and distributes in the fiber 1 as shown in FIG. The vibration applied to the table T may be horizontal vibration as indicated by an arrow H or vertical vibration as indicated by an arrow V.

When the mixture 2 is substantially uniformly distributed in the fiber 1, primary heating is performed by a heating means such as a heating coil 3 as shown in FIG. The mixture 2 is melted by the primary heating, and a primary molded product 4 in which the fibers 1 are uniformly distributed is completed. The primary molded product 4 is in a felt shape, and is moved from the table T to the heating and pressurizing means HP, and is heated and pressurized to complete the molded product (FIG. 5). In this heating and pressurizing step, uniform foaming is performed. (Note that the step of performing primary heating shown in FIG. 3 can be omitted.) A plate made of a material such as paper or high-density glass fiber is laminated on the primary molded product 4 and heated and pressed. Then, the strength of the molded product is improved.

Here, the heating temperature and heating time in the heating and pressurizing step are such that the thermoplastic foamed resin does not foam and the cells do not become rough due to abnormal foaming, specifically, 140 ° C. to 200 ° C. Set from 1 minute to 10 minutes. The pressure is set in a range such that the mold is not lifted by the generation of gas.

When it is desired to increase the thickness of the molded product, the fibers 1 may be superposed in a plurality of layers as shown in FIG. 6, and the mixture 2 may be mixed and superimposed. In FIG. 6, voids are shown between the layers of the fibers 1, but this is for realizing that a plurality of the fibers 1 are superimposed, and in fact, voids are formed between the layers of the fibers 1. There is no need to do it.

Although long fibers are used in the illustrated example, relatively short glass fibers or the like may be used.

Hereinafter, examples in which materials and numerical values are more specifically limited will be described.

Example 1 Glass fiber, especially Asahi Fiberglass, trade name "CSM" (continuous strand mat) or trade name "CM" (chopped strand mat) as a sublime fiber 1 and a thermoplastic foam resin Matsumoto Resin Pharmaceutical product name "Matsumoto Microfair F-50"
It was used. This thermoplastic foamed resin is obtained by adding a foaming gas to a vinylidene chloride or acrylonitrile-based resin and inflating the resin.

330 g / m overlapping sublime base material formed of glass fibers of a continuous having a surface density of 300 g / m ² in a mat shape on the chopped mat glass fibers having a ^second surface density, thermoplastic foam thereon A phenol resin in which 20% of the resin and 5% of dinitropentamethylenediamine are mixed is applied at a rate of 800 g / m ² . When vibration is applied, the resin is sufficiently dispersed among the noble fibers. Thereafter, the mixture was thermoformed at 150 ° C. for 2 minutes at a pressure of 10 kg / cm ² while keeping an interval of 5 mm to produce a fiber-reinforced foamed phenol molded product.

The density of the fiber-reinforced foamed phenol molded product thus obtained is 0.2. For bending strength, see JIS K-69
The measurement was performed with the chopped top strand mat on the upper side in accordance with the general thermosetting plastic test method of No. 11. As a result, the flexural strength is 0.7-0.8 kg / mm ^2, which is a 20-30% improvement over molded articles reinforced with non-sublime glass fibers of equivalent areal density.

The bending and disconnection rate is 60 kg / mm ² , and 40 with a load of 0.5 kg / mm ²
It did not break even when the load of the bending external force was repeated repeatedly. However, a molded article reinforced with a non-sublime glass fiber having the same areal density was destroyed by one bending (destruction of the foamed resin layer).

No dripping of resin powder is seen on the surface of the molded product. In addition, the condition of the foam layer is uniform without any roughness.

Example 2 on the mat natural palm rock fiber having a surface density of 500 g / m ^2, the thermoplastic foam resin 10% phenolic resin 700 g / m ² comprising dinitrosopentamethylene diamine 50%
Apply at the ratio of When vibrated, the applied resin is well dispersed among the noble fibers. Thereafter, the fiber-reinforced foamed phenol molded article is manufactured by heating and pressing at 150 ° C. for 2 minutes at a pressure of 10 kg / cm ² while maintaining an interval of 5 mm as the thickness dimension.

The density of this molded product is 0.2. The flexural strength was measured in accordance with JIS K-6911 general thermosetting plastic test method. As a result, the bending strength is 0.6-0.7kg
a / mm ^2. The flexural modulus was a strength of 40 kg / mm ² . And it did not break even after repeating bending 40 times at a strength of 0.4 kg / mm ² . Furthermore, on the surface of the molded product,
No resin powder dripping was seen. In addition to this, the condition of the foamed layer is uniform without any roughness.

[Curing of the Invention] The curing of the present invention described above is enumerated below.

(A) Since the fibers are uniformly distributed over the entire molded product, the strength is greatly improved, and the composition of the molded product is uniform, so that there are no partially weak portions. As a result, the physical properties of the molded article, particularly the bending / peeling strength, are remarkably improved, and a lightweight and durable molded article is obtained.

(B) Since the thermoplastic foam resin acts as a binder, it is possible to prevent the cloud from dropping from the surface of the foam molded article.

(C) Since the mixing ratio of the thermoplastic foamed resin is appropriate, a molded article having flame retardancy and excellent properties such as light weight, soundproofing properties, heat insulation properties, workability, and strength can be obtained. Thus, it can be suitably used for interior materials of automobiles, furniture, interior and exterior materials for buildings, and the like.

(D) The range of conditions for foam molding is expanded, and a fiber-reinforced foamed phenol molded article having various properties can be provided.

(E) The strength of the molded article can be improved by laminating a plate made of a material such as paper or high-density glass fiber on the surface of the molded article by primary heating.

[Brief description of the drawings]

1 to 5 are side views in which various steps in one embodiment of the present invention are arranged in time series, and FIG. 6 is a side view showing another embodiment of the present invention. 1 ... fiber, 2 ... mixture, 3 ... primary heating means 4 ... primary molded product, HP ... heating and pressurizing means T ... table

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29L 31:44 31:58

Claims (1)

(57) [Claims] 1. A phenolic resin containing a foaming agent and a thermoplastic foaming resin are mixed so that the mixing ratio thereof is 3 to 30 parts by weight of the thermoplastic foaming resin with respect to 100 parts by weight of the phenolic resin. A step of spraying the mixture on the upper surface of the sublime fibers, a step of applying vibration to the fibers sprayed with the mixture to uniformly penetrate the mixture into the fibers, and a step of heating the mixture and the fibers to primarily heat the felt. The thermoplastic resin which has entered between the fibers by heating and pressing the felt-like molded product by the primary heating at a temperature and for a time such that the thermoplastic foamed resin foams and the cells do not become rough due to abnormal foaming. A step of expanding the foamed resin and the phenolic resin containing the foaming agent, and filling the foamed thermoplastic foamed resin and the phenolic resin between the fibers without gaps. Method for producing a fiber-reinforced foamed phenolic molding to.