JPS5832169B2 - Expandable resin granule composition. The molded object and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a foamable thermoplastic resin particle composition, a foam molded product obtained therefrom, and a method for producing the same.

In more detail, it significantly shortens the maturing time in the production of molded products that require a cell structure, and also significantly shortens the cooling time, which takes up a large amount of time during the molding process, and produces homogeneous molded products. The present invention relates to an invention that can provide antistatic effects as well as antistatic effects.

A typical thermo-ET plastic resin foam is produced by pre-foaming thermoplastic resin particles containing a blowing agent that is liquid or gaseous at room temperature to a desired apparent specific gravity by steam heating in an open or closed container. Leave the grains for about 24 to 48 hours to stabilize the internal conditions such as the blowing agent distribution within the grains,
- After homogeneous foaming, the pre-expanded particles are fused together by heating and secondary foaming in a mold to produce a molded product.

However, in this conventional method, the
Since a very large-capacity aging tank is required for long-term aging of pre-expanded grains expanded to 0 times, it is desired to shorten this aging period.

If the ripening time is forcibly shortened and molded, the molded product will not be homogeneous and will significantly lose its commercial value.

Furthermore, it has been pointed out that during pre-foaming, pre-foamed particles adhere to the walls of the pre-foaming tank due to the moisture of the steam and remain there, becoming waste, resulting in loss of raw materials.

Furthermore, the length of the molding cycle during molding determines immediate productivity, but especially in the case of block molding, about 80 to 85% of one cycle is consumed for cooling the entire molded product in the mold, and Shortening the time has been a long-standing issue.

Furthermore, there is a large difference in specific gravity between the surface and the interior of the molded product, and homogenization is essential for increasing commercial value, but no suitable solution has yet been found.

Already recognizing 2.3 of these shortcomings, JP 50-1
No. 40574 proposes treating expandable particles with unsaturated fatty acids or dimers or trimers of unsaturated fatty acids and esters of these with alcohols.

However, the effect of shortening the cooling time is not fully satisfactory, and there is no mention of shortening the aging time, improving the homogeneity of the foam, or improving the chargeability.

The present invention solves all of these problems at once, and has achieved remarkable productivity improvements by shortening the ripening time to about 1/4 to 115 of the conventional time and the cooling time to about 40 to 50%. In addition to significantly reducing the generation of waste during pre-foaming, the product also improved the homogeneity and chargeability of the product, and succeeded in bringing about tremendous effects.

That is, a foamable resin prepared by mixing 0.05 to 1.5% by weight of a molding improver represented by the following general formula to foamable thermoplastic resin particles impregnated with a foaming agent that is liquid or gaseous at room temperature. Grain composition.

formula X RN<.

Y: C-(CH) m-o-), -Z, X
: Y or H] R' R: C6-24 alkyl or alkenyl R' :
H or C1,3 alkyl Z: residue obtained by removing the OH group from an organic carboxylic acid, provided that m, n
refers to a positive integer of 10 or less, a foam molded product obtained by foaming this resin particle composition, and a method for producing the same.

The expandable thermoplastic resin particles referred to in the present invention are thermoplastic resins, such as polystyrene or styrenic copolymers (random, block, and graft copolymers) obtained by polymerizing with a minor amount of a monomer copolymerizable with styrene. (including combination)
, polyolefins such as polyethylene and polypropylene, or polyolefin copolymers including random, block or graft copolymers formed by copolymerizing with the addition of monomers that can be copolymerized with olefins, as well as blowing agents described below. A known thermoplastic resin that can be impregnated with
These are expandable resin granules obtained by impregnating a known foaming agent in the form of foam or gas at room temperature.

Generally, expandable polystyrene particles or expandable polyethylene are often used and are highly effective.

Examples of blowing agents include ethane, ethylene, propane, propylene, butane, butylene, isobutane, pentane,
Examples include aliphatic hydrocarbons including neopentane, hexane, and mixtures thereof, chlorinated hydrocarbons, fluorinated hydrocarbons, chlorofluorinated hydrocarbons, and inorganic gases such as nitrogen, oxygen, and air.

Furthermore, the molding improver referred to in the present invention is represented by the following general formula.

X: Y or hydrogen R: Ca, 4 alkyl or alkenyl R': H or C1-3 alkyl Z: residue obtained by removing the OH group from an organic carboxylic acid, provided that m, n
is a positive integer of 10 or less The organic carboxylic acids referred to herein include, for example, C6,4 fatty acids, benzoic acid, salicylic acid, phthalic acid, C1,4 alkylbenzoic acids, C1-14 alkenylbenzoic acids, C2,
C6-24 fatty acids are particularly preferred, and C18 fatty acids, that is, stearic acid, are particularly preferred from the viewpoint of cost.

Stearyl is also advantageous for R in the general formula from the viewpoint of cost and other considerations.

Among these, for example, ethane 331P (Marubishi Yuka Kogyo KK
) is polyoxyethylene stearylamine stearate, a pale yellow powder with an acid value of 5, m, p, 41°C,
It is a substance that is insoluble in water but soluble in organic solvents such as propatool, benzene, chloroform, and ether.

In order to mix the molding improver with the expandable thermoplastic resin particles described above, there is no need to use any special method, and it is sufficient to simply mix the two, and it is preferable to use a stirring device to mix uniformly.

Alternatively, the molding improver can be heated above its melting point and added in the form of a liquid.

The mixing ratio of the molding improver is 100% foamable thermoplastic resin particles.
Approximately 0.05 to 1.5 parts by weight are suitable.

If the amount is less than about 0.05 parts, the effect of the present invention will be weak, and if it is more than about 1.5 parts by weight, the molded article will shrink, which is not preferable.

Further, the mixing ratio is more preferably 0.1 to 1.0 parts by weight.

The foamable resin particle composition thus obtained is heated in a pre-foaming tank to pre-foam it to a desired expansion ratio.

The molding improver added in solid form is melted in this pre-foaming process, and is pre-foamed in a state in which it is uniformly adhered to the surface of the expandable thermoplastic resin particles.

In the case of foaming polystyrene, if the molding improver is added after the preliminary foaming is completed, its effect will not be exhibited.

Next, the pre-expanded grains are transferred to a maturing step, where they are uniformly expanded in secondary foaming and left at room temperature or its vicinity until a uniform molded product is obtained.

Furthermore, the pre-expanded grains that have been aged are filled into a mold that can be closed but cannot be sealed, and subjected to secondary foaming by heating with steam, etc.
A molded body as a final product is obtained.

However, the foaming process described above is mainly for foamed polystyrene, and various foaming operations may be performed for materials other than foamed polystyrene, and accordingly, changes may be made as appropriate without departing from the gist of the present invention. It is possible.

The effects of the present invention are listed below.

1. Since the cooling time can be greatly reduced, the residence time in the mold is shortened, and the production volume can be greatly increased.

2゜Dust does not adhere to the product surface due to its antistatic effect.

3. There is extremely little variation in the specific gravity distribution inside the large block molded product.

4. The ripening time is greatly shortened.

5. There is little waste generated during pre-foaming, and uniform foamed grains can be obtained.

6. The air flow inside the pipe is good and the mold filling effect is good.

7. Improved surface hardness of molded products.

Example 1 Polyoxyethylene stearylamine stearate, ie, amine 33, was added as a molding improver to expanded styrene beads (Kanepal KO beads, manufactured by Kanebuchi Kagaku Kogyo KK).
1P (manufactured by Marubishi Yuka Kogyo KK) was added in an amount of 0.5 parts by weight, stirred in a ribbon blender for 5 to 10 minutes, and pre-foamed by steam heating in a pre-foamer for about 2 minutes. Since the molding improver is melted and adhered to the bead surface, it has extremely good fluidity and does not adhere to the walls of the pre-foaming tank, so there is no blocking phenomenon due to overheating and no loss due to generation of debris is observed.

Furthermore, since it has excellent fluidity, it does not get clogged in the transport pipe due to blocking and flows as a complete single grain.

The pre-expanded pellets were aged at room temperature for 5 hours, then filled into a flock molding mold (300 x 400 x 140 mm) and foamed using a normal heating method. After cooling to a state where it could be taken out (this cooling time was 67 seconds), it was released from the mold to obtain a product with a molded body density of 14.

Despite the short aging time of 5 hours, the obtained molded product was not deformed after molding (had sufficient commercial value), and the cooling time was short (it was highly economical (it had low chargeability).

The results are shown in Table 1.

Comparative Example 1 Pre-foaming in the same manner as in Example 1 without using a molding improver, 5
After aging for an hour, foaming and cooling for 295 seconds, which can be released from the mold.
The obtained molded product having a density of 14 was unsuitable as a commercial product because of the insufficient aging time, resulting in severe formation after release from the mold, and was easily charged with electricity.

In addition, beads adhering to the tank wall during pre-foaming become debris, resulting in loss, and the transport of the pre-foamed grains to the aging tank and molding machine also has poor fluidity and tends to cause blocking phenomena.

The results are summarized in Table 1. Example 2, Comparative Row 2 An experiment was carried out in accordance with Example 1 and Comparative Example 1, except that Kanepal KM beads were used.

Example 2 is a case in which the same long aging time as required for the conventional product was taken, and good molding was possible in this case as well, and the specific gravity distribution between the inside and outside of the product of the present invention was small and uniform. Good quality and short cooling time.

The results are shown in Table 2.

Example 3, Comparative Example 3 Same as Example 2, except that large block (1800X900
An experiment was conducted as shown in Table 3 using a molding machine (x400 mm).

In the present invention, an excellent product with a short cooling time and a small specific gravity distribution was obtained.

Example 4, Comparative Example 4 The same flock was molded according to Example 1.

However, 0.64 parts of molding improver and 0.16 parts of glyceride
A mixture of parts was used.

The results are shown in Table 4, and it can be seen that the effects of the present invention were maintained even when a small amount of additives were added in addition to the molding improver, demonstrating the superiority of the effect of shortening the curing time and cooling time.

Example 5, Comparative Example 5 1.0% by weight of the same molding improver as in Examples 1 to 4 was added to foamed polyethylene pre-expanded beads (Eperan raw particles: manufactured by Kanekabuchi Chemical Industry KK) to produce a 1-nopon blender. 5~
The mixture was stirred for 10 minutes, heated with steam for about 2 minutes to uniformly adhere to the particle surface, then filled into the same mold as in Example 1, and immediately heated with steam to give a foaming ratio of 30 times. A molded body was obtained.

Claims (1)

[Scope of Claims] 1. About 0.05 to 1.5 parts by weight of a molding improver represented by the following general formula is added to 100 parts by weight of expandable thermoplastic resin particles impregnated with a liquid or gaseous blowing agent at room temperature. A foamable resin granule composition formed by mixing parts by weight. Formula % Formula %: R: Ca, 4 alkyl or alkenyl R: H or C1-3 alkyl Z: Residue obtained by removing the OH group from an organic carboxylic acid, provided that m, n
is a positive integer of 10 or less 2 The foamability according to claim 1, wherein the molding improver is N-N-di (or N-mono) polyoxyalkylene alkylamine di (or mono) fatty acid ester Resin particle composition. 3. The expandable resin granule composition according to claim 2, wherein the molding improver is N-N-di (or N-mono) polyoxyethylene stearylamine di (or mono) stearate. 4. The expandable resin particle composition according to claim 1, 2, or 3, wherein the expandable thermoplastic resin particles are polystyrene-based or polyolefin-based. 5. The expandable resin granule composition according to claim 4, wherein the mixing ratio of the molding improver is 0.1 to 1.0 parts by weight. 6. About 0.05 to 1.5 parts by weight of a molding improver represented by the following general formula is mixed with 100 parts by weight of expandable thermoplastic resin particles impregnated with a liquid or gaseous blowing agent at room temperature, A thermoplastic resin foam molded product is then foamed. Formula % Formula %: R: C6,4 alkyl or alkenyl R': H or C1-3 alkyl 2: Residue obtained by removing the OH group from an organic carboxylic acid, provided that m, n
is a positive integer γ of 10 or less. The thermoplastic according to claim 6, wherein the molding improver is N-N-di (or N-mono) polyoxyalkylene alkylamine di (or mono) fatty acid ester Resin foam molding. 8. The thermoplastic resin foam molded product according to claim 7, wherein the molding improver is N-N-di (or N-mono) polyoxyethylene stearylamine di (or mono) stearate. 9. The thermoplastic resin foam molded product according to claim 6, 7, or 8, wherein the expandable thermoplastic resin particles are polystyrene-based or polyolefin-based. 10. The thermoplastic resin foam molded product according to claim 9, wherein the mixing ratio of the molding improver is 0.1 to 1.0 parts by weight. 11 About 0.05 to 1.5 parts by weight of a molding improver represented by the following general formula is mixed with 100 parts by weight of expandable thermoplastic resin particles impregnated with a liquid or gaseous blowing agent at room temperature. A method for producing a thermoplastic resin foam molded product, which comprises pre-foaming, aging in air, and molding in a mold. Formula % Formula %: R: C6,4 alkyl or alkenyl R': H or C1-3 alkyl Z: Residue obtained by removing the OH group from an organic carboxylic acid, provided that m, n
is a positive integer of 10 or less 12 The heat 1 according to claim 11, wherein the molding improver is N-N-di (or N-mono) polyoxyalkylene alkylamine di (or mono) fatty acid ester
8iT plastic resin foam molded product manufacturing method. 13. The method for producing a thermoplastic resin foam molded product according to claim 12, wherein the molding improver is N-N-di (or N-mono) polyoxyethylene stearylamine di (or mono) stearate. . 14. Claims 11 and 12, wherein the expandable thermoplastic resin particles are polystyrene-based or polyolefin-based.
The method for producing a thermoplastic resin foam molded product according to item 1 or 13. 15. The method for producing a thermoplastic resin foam molded product according to claim 14, wherein the mixing ratio of the molding improver is 0.1 to 1.0 parts by weight.