JPS59222318A - Forming method of flame-retardant foam plastic formed product - Google Patents

Abstract

PURPOSE:To obtain a formed product which is not inferior to others in smoothness and shape reproducibility and also is excellent in hardness, wear proofness and flame resistance by causing a foaming resin of which foam generative solution contains glass fibers, mica, etc. to impregnate in a glass fiber mat or nonwoven fabric arranged on the surface of a metal mold. CONSTITUTION:At the time of foam genertive forming, a foam generative resin to be obtained from undiluted solution containing mica and/or glass fibers is caused to impregnate in a sheet of nonwoven fabric or a mat of glass fibers. It is preferable to use mica flakes or mica powder of which average grain diameter is about 0.03-1.0mm. and short glass fibers measuring 0.002-0.01mm. in diameter and 0.5-5.0mm. in length, since they are excellent in dispersion in undiluted solution, collectability on glass fiber mat or nonwoven fabric and they are well entangled by a mixer at the time of mixing in undiluted solution. It is also preferable to keep the percentage of mica and (or) glass fiber occupied in undiluted solution less than about 5-60% in view of workability, ensemble property on the surface layer, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molding method for forming a surface layer made of a composite of a low-density foamed plastic and a noncombustible material in order to improve the flame resistance of a low-density foamed plastic molded article.

Low-density foamed plastics such as foamed polyurethane have lower flame resistance than resins or high-density foams because the resin portion has a larger air contact area. Therefore, the flame resistance of ordinary low-density foamed plastic molded products is determined by adding flame retardance to the molded product itself using raw materials containing flame retardants, or
They are trained by methods such as coating the surface of molded products with other flame-retardant materials. However, the former method has drawbacks such as components such as chlorine contained in flame retardants impairing the properties of plastics and corroding metals used as surface coating materials and insert parts. Even if a flame retardant is used, it is extremely difficult to maintain sufficient flame retardance for a long time. In the latter method, inorganic materials are mainly used as other flame-retardant components, and after the inorganic materials are molded to have the same shape as the molded product, the parts are bonded to the foam molded product, etc. There are many problems in manufacturing, such as the number of man-hours required for fixing.

In order to solve the problems of the conventional method in manufacturing low-density foamed plastic molded products with flame resistance as described above, the present inventor formed a layer containing a large amount of non-combustible material on the surface of the molded product. As a result of extensive research with the aim of improving By manufacturing a flame-retardant foamed plastic molded product that has a surface layer with excellent flame resistance even at low density, which can be obtained by impregnating it with a foamed resin obtained from When flame retardants are used, the properties of plastics may be damaged, metals used as surface coating materials or insert parts may be damaged, and it may be difficult to maintain flame retardancy permanently. It is remarkable that flame-retardant foamed plastic molded products can be replaced without causing defects and without causing manufacturing problems such as increasing the number of man-hours required to coat the surface of the molded product with other flame-retardant materials. The present invention was completed based on these results.

There are no particular limitations on the nonwoven fabric or glass fiber mat used in the present invention, but in order to obtain low-density foamed plastic molded products, it is necessary to faithfully reproduce the shape of the mold, and to do so, it is necessary to It is necessary that the resulting foamed resin be easily impregnated into the nonwoven fabric or glass fiber mat and reach the mold surface. Therefore, it is preferable to use a nonwoven fabric or glass fiber mat with a wide interfiber distance of about 10 to 5 [1i'%/m2] as the surface composite material. However, using such a nonwoven fabric or glass fiber mat alone does not provide the desired flame resistance because the content of nonflammable inorganic substances in the surface layer is insufficient. Therefore, in the present invention, another noncombustible material is contained in the stock solution, and the other noncombustible material is concentrated in the surface layer when impregnated into a surface material such as a nonwoven fabric or a glass fiber mat that is accompanied by the foaming of the foamed resin. As a result, the content of nonflammable substances in the surface layer is increased, and the flame resistance of the foamed plastic molded product is dramatically improved without impairing the reproducibility and smoothness of the mold shape on the surface.

The mica and/or glass fibers used in the present invention are used as other nonflammable substances added to the stock solution, such as mica flakes or mica powder with an average particle size of about 0.03 to 1.0 mm. Diameter 0.00
Short glass fibers with a diameter of 2 to 0.01 mm and a length of 0.5 to 5.0 mm can be easily dispersed in the stock solution, aggregated on glass fiber mats or nonwoven fabrics, and tangled in the mixer when mixing the stock solution. It is preferable from the point of view.

The stock solution used in the present invention is a stock solution in which mica and/or glass fibers are added to a usual stock solution of incyanurate foam, a foaming stock solution such as BORIURESO/YOYO, or a composition thereof. Mica and/or in stock solution
The proportion of glass fiber is preferably about 5% or more and about 60% or less from the viewpoint of workability, ability to aggregate in the surface layer, etc.

When the stock solution used in the present invention is an incyanurate 7 ohm stock solution, the rotation speed is several thousand 1 PM after adding mica and/or glass fiber to the P solution, which is one of the stock solutions of incyanurate foam. Stir with a mixer to uniformly disperse, then add the other R solution of the incyanurate 7 ohm stock solution, add other ingredients as necessary, stir quickly, make uniform, and then quickly It is necessary that it be used. This is because normally prepared stock solutions start foaming in a few seconds, so they must be poured into the mold quickly. Filling the mold is usually 20 to 4
Although the reaction is completed in about 0 seconds, it is preferable to leave the reaction at 40 to 80 degrees for about 0.3 to 20 minutes until the reaction is completed and the molded product is taken out, in order to obtain a molded product with a more stable shape. The foamed resin that has reached the nonwoven fabric or glass fiber mat during the filling process is impregnated with the nonwoven fabric or glass fiber mat as it passes through the gaps in the nonwoven fabric or glass fiber mat, destroying the bubbles and turning them into resin.

However, since mica and/or glass fiber particles do not pass through this glass fiber mat, a high-density layer impregnated with a high concentration of incombustibles is formed on the surface layer, and the foaming pressure of the isocyanurate foam allows this layer to be molded into the mold. It is pressed tightly against the surface and accurately reproduces the mold shape.

FIG. 1 shows a schematic partial cross-sectional view of an example of a flame-retardant foamed plastic molded article obtained by the method of the present invention as described above. In Figure 1, (1) is glass fiber pine),
(2) is glass fiber, (3) is bubble, (4) is resin, (
5) is the surface layer, and (6) is the inner layer.

Next, the method of the present invention will be explained based on Examples and Comparative Examples.

Example 1 P Engineering R-01-P (isocyanurate 7 ohm stock solution
Add 40 parts of tin olide mica 200HK (mica flakes, manufactured by Kuraray) to 100 parts (parts by weight, same applies hereinafter) of P liquid (manufactured by Narita Pharmaceutical Co., Ltd.), and mix for 6 seconds with a mixer at 600 RPM as a premix. After stirring, 20 parts of P-Ko R-01-R (isocyanurate foam stock solution R, manufactured by Narita Pharmaceutical Co., Ltd. (Ichita)) was added and stirred rapidly for 6 seconds to prepare a stock solution (hereinafter referred to as stock solution 1).

50 parts A glass fiber mat (
After installing a 23%/m 2 chop mat (manufactured by Asahi Fiberglass ■), stock solution 1 was poured into the mold and completely filled in about 30 seconds. Since foaming of stock solution 1 starts after 5 to 6 seconds, it was necessary to quickly pour it into the mold.

After filling, a molded article having a stable shape was obtained by leaving it for about 6 minutes in an atmosphere of about 80°0.

The surface layer and internal layer of the obtained molded product are heated respectively,
Each composition ratio was determined based on the residual heating. The results are shown in Table 1.

On the other hand, in order to evaluate the flame resistance of the molded product according to the present invention in 1 various flame resistance test methods, samples used in the tests shown in Table 2 were molded using a mold for making flame resistant samples, and the flame resistance was evaluated. I did it.

The results are shown in Table 2. The outline of the test method shown in Table 2 is as follows. UL-94 is a horizontal combustion test for predetermined molded products, JIS K 7201 is a measurement of oxygen index, and a flame retardant test for materials for railway vehicles is an ignition test on an inclined surface.

Example 2 In place of the mica in stock solution 1 used in Example 1, length 2.
A stock solution was prepared in the same manner as in Example 1 except that 0an glass fiber was used, a molded article was produced, and the components of the surface layer and inner layer of the molded article were analyzed.

The results are shown in Table 1. In addition, flame resistance was measured in the same manner as in Example 1. The results are shown in Table 2.

Example 6 + 100 parts of 1904-231 liquid (manufactured by Toyo Com Industries H) 86 parts of Niszuolite Mica 200) IK were added and stirred for 6 seconds with a mixer at 6000 rotations as a premix, and then +1904-26 P Liquid (manufactured by Toyo Rubber Industries)
102 parts were added and rapidly stirred for 6 seconds to prepare a stock solution (hereinafter referred to as stock solution 2). A glass fiber mat (10%/m
After attaching the Surf Acing Mat No. 2 (manufactured by Asahi Fiberglass ■), stock solution 2 was poured into the mold and filled in the same manner as in Example 1. Immediately after filling, the mold was sealed, and the molded product was taken out after being left for 5 minutes.

Flame resistance was measured in the same manner as in Example 1 using the obtained molded article as a flame resistance test sample. The results are shown in Table 2.

Example 4 The glass fiber mat used in Example 6 was made of Soflon 1017.
Example 6 except that the material was changed to (non-woven fabric, made by Daio Paper 01)
A flame resistance test sample was prepared in the same manner as above, and the flame resistance was measured. The results are shown in Table 2.

Example 5 Mytic 7 ohm (free form density 30 kp/m
A glass fiber mat was prepared as a surface material in the same manner as in Example 6 using the incyanurate foam stock solution of No. 3 (manufactured by Kasei Upjohn ■) and adding tin olide mica 200HK so that the stock solution contained 10%. A molded article was produced, and its flame resistance was measured in the same manner as in Example 1. The results are shown in Table 2.

Example 6 A molded article was produced in the same manner as in Example 5, except that the concentration of tin olide mica 200HK used in Example 5 was changed from 10% to 40%, and the flame resistance was measured. The results are shown in Table 2.

Comparative Example 1 A sample was prepared in the same manner as in Example 1 except that the tin olide mica 200HK and glass fiber mat used in Example 1 were not used, and the flame resistance was measured. The results are shown in Table 2.

Comparative Example 2 A sample was prepared in the same manner as in Example 6, except that the tin olide, mica 200EK, and glass fiber mat used in Example 3 were not used, and the flame resistance was measured.

The results are shown in Table 2.

Comparative Example 6 A sample was prepared in the same manner as in Example 6 except that the tin olide mica 200 HK used in Example 5 and the glass fiber mat were not used, and the flame resistance was measured.

The results are shown in Table 2.

Table 2 As shown in Table 1, the surface layer contains about 7.5 times more incombustibles (mica and glass) than the inner layer of the molded product. The flame resistance of the molded article according to the invention is improved. The effects of using non-combustible materials on the flame resistance of molded products are as follows: Comparison of resistance when using isocyanurate foam between Example 1 or 2 and Comparative Example 1, and Bourethane 7 between Example 3 or 4 and Comparative Example 2. It is clear from the comparison of the flame resistance ratio when using ohmic or Example 5 or 6 and Comparative Example 3 when using another type of isocyanurate foam. When a molded article is produced using a non-combustible material by the method of the present invention, its flame resistance is improved by 1 to 2 classes compared to when no non-combustible material is used.

The low-density flame-retardant plastic molded product of the present invention is produced by impregnating a glass fiber mat or nonwoven fabric placed on the mold surface with a foamed resin containing glass fiber, mica, etc. in a foamable stock solution such as a polyurethane stock solution. be done. The obtained surface layer is comparable in smoothness and mold shape reproducibility to surface layers obtained from foamed resins that do not contain glass fiber or mica, and has excellent mechanical properties such as hardness and abrasion resistance. Therefore, the molded product according to the present invention is also suitable as a member for air passages or waterways.

As mentioned above, according to the method of the present invention, the surface layer of the foamed plastic molded product has a structure containing a high concentration of incombustible materials, so it is possible to produce a molded product with extremely excellent flame resistance.

[Brief explanation of drawings]

FIG. 1 shows a schematic partial sectional view of an example of a flame-retardant foamed plastic molded article obtained by the method of the present invention. (Main symbols on the drawings) (1) Glass fiber mat (2): Mica and/or glass fiber (3): Air bubbles (4): Resin agent Masuo Oiwa (and 2 others) No. 1 Same

Claims (1)

[Claims] (1) Flame resistance is achieved even at low density by impregnating the nonwoven fabric or glass fiber mat attached to the mold during foam molding with foamed resin obtained from a stock solution containing mica and/or glass fiber at 5% by weight or more. A method of molding a flame-retardant foamed plastic molded product characterized by having an excellent surface layer.