JPS58189236A - Production of extruded foam - Google Patents

Abstract

PURPOSE:To obtain inexpensively an extruded foam having natural wood-like appearance, excellent flexural strength, density, etc., by extrusion-expanding a mixture of a styrene resin and hulls of cereals. CONSTITUTION:A styrene resin (A) obtd. by (co)polymerizing a styrene monomer such as styrene, alpha-methylstyrene of vinylstyrene and hulls (B) of cereals such as rice or wheat are mixed in a weight ratio of B/A of 0.5/95.5-20/80. It is preferred to previously impregnate component B with a solvent capable of dissolving component A, such as benzene or toluene, or with a wetting agent capable of swelling component A, such as hexane or octane. The mixture is supplied to an extruder. A blowing agent such as propane or butane is introduced thereinto under pressure. The mixture is kneaded and extruded to obtain the desired extruded foam.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing extruded foam having a wood-like appearance.

Conventionally, extruded styrene resin foam has been called synthetic wood because of its appearance similar to wood, but if you look closely, you can't get over the impression that it is plastic. In order to make the appearance more similar to wood, methods such as ■using colorants and ■pasting woodgrain pattern paper are known, but in method (■), the colorant is expensive, and method It is not economical as it requires an additional process of pasting.

The present invention solves these problems and provides an extruded foam whose appearance more closely resembles that of natural wood.

That is, the present invention relates to a method for producing an extruded foam, which is characterized by extruding and foaming a styrene resin and grain shells.

In the present invention, the styrene resin refers to a polymer or copolymer of a styrene monomer, a copolymer of a styrene monomer and another monomer, and the like.

The shape is arbitrary, but particles such as spherical particles and pellets are preferable.

Examples of the styrene monomer include styrene, α-methylstyrene, and t-butylstyrene.

There are substituted styrenes such as chlorostyrene 5-vinyltoluene, and other monomers include acrylonitrile, butadiene, and the like. The above-mentioned styrene resins include those obtained by graft polymerizing a styrene monomer in the presence of polybutadiene, polybutyl acrylate, or the like. This type of styrene resin has 50 parts of styrene as a polymerization component! i
It is preferable to include 2% or more.

A blowing agent is required to foam styrene resin, and this foaming agent can dissolve styrene resin, such as aliphatic hydrocarbons such as propane, butane, and pentane, and halogenated aliphatic hydrocarbons such as chlorofluorocarbons. No readily volatile compounds are used. The foaming agent may be impregnated into the styrene resin in advance, or the foaming agent may be press-fitted during extrusion of the styrene resin (fat and grains) and kneaded and impregnated with them. In any case, it is preferable that the blowing agent is impregnated with the styrene resin in a proportion of 1 to 10% by weight.

-F styrenic resin may contain other additives.

Examples of the above-mentioned grain husks include rice husks, wheat husks, and peanut husks.

It is preferable to peel it and use it in the form of fibers, or to crush it and use it in the form of powder or granules. It is preferable that the fibrous material has a length of about 1 to 21 m, and the granular material that can pass through an 80-mesh sieve is preferable.

For grain shells, 1 liter of styrene resin can be dissolved in advance.
(For example, benzene, toluene, and quince.

Styrene, ethylbenzene, etc.), styrene thread
+ Swelling agent that does not dissolve but can swell (e.g., hexane, cyclohexane, heptane, octane, etc. with 6 or more carbon atoms)
It is preferable to impregnate the resin with an aliphatic hydrocarbon (e.g., No. 8) in order to increase the affinity with the styrenic camellia fat. The above-mentioned solvent or swelling agent is preferably used in an amount of 0.1 to 20 weight percent, particularly preferably 1 to 10 weight percent, based on the shell.

If it is less than 0.01% by weight, the above effect will be small, and if it exceeds 20% by weight, the properties of the extruded foam will tend to deteriorate.The impregnation method is preferably carried out using a high-speed rotating mixer such as a Henschel mixer.

Grain shell (Al and styrene resin FB+ are (A) / (
Preferably B) is used in a weight ratio of 0.5/95.5 to 20/80. When the ratio is less than 0.5/95.5, the effect of improving the appearance is small, and when it exceeds 20/80, the bending strength of the extruded foam tends to decrease. Considering the bending strength of the extruded foam, it is particularly preferable to use the extruded foam in such a manner that ((B)/(B) is 5/95 to 16/84 (weight ratio).

To perform extrusion foaming, an extruder is used to charge the foamable styrene resin and grain shells through the extruder's hopper, the foamable styrene resin is melted in the extruder, and the mixture is kneaded with the grains and extruded. Sane Ru. In addition, the styrene resin and the grain husks are all kneaded in an extruder in the same manner as above, and a blowing agent is press-fitted from the middle of the extruder cylinder, and the mixture is further kneaded and extruded. in this case.

of expandable styrenic resin or styrenic resin and grain,
Preferably, the ingredients are mixed before being charged to the extruder hopper. At the tip of the extruder is a T-die and irregular-shaped die.

A die such as a circular die is attached, and a sizing die is used as appropriate to form the desired shape.

After the molded product is extruded from the die, it is cooled by air cooling, water cooling, or the like. The cylinder temperature of the extruder is approximately 90-15
The temperature is 0°C, the feed section is low and the compression section is high. Note: 1. When press-fitting the foaming agent in the middle.

1 pa Preferably, this compression chamber is used. To dice temperature Preferably, the temperature is about 100-120°C.

In the extrusion foaming process, cell conditioners such as calcium carbonate, Merck, calcium stearate, zinc stearate, etc.
Inorganic pigments such as red iron oxide and titanium white, organic dyes, etc. may be added. The cell conditioner is 0.0% relative to the styrene resin.
It is preferable to use the inorganic pigment and organic dye in an amount of 0.05 to 5.0 by weight, and the inorganic pigment and organic dye are usually used in an amount of 0.2 to 12 or less per styrene resin.

The present invention will be explained in detail with reference to Examples, but is not limited thereto.

K) Grain shell A: Bean nut shells were defibrated to 60 mesh or less using a defibrator and dried. 100 parts by weight of this shell fiber was placed in a Hensiel mixer, and while stirring at room temperature at 200 rpm, 5 parts of styrene was added over 2 minutes.
Mix by stirring for a minute. The obtained flour is referred to as grain shell A.

6-(2) Grain husk B 5 parts of dicyclohexane was stirred and mixed with a Hennel mixer under the same conditions as in Example 1 to 100 layers of wheat husks of 100 mesh or less. The obtained flour is referred to as grain shell B.

Examples 1 to 6 and Comparative Example 1 Expandable polystyrene beads (...Ibeez 8B.

Hitachi Chemical ■Product name (contains butane 3-11-4).

Grain husk A, 100 ψ of talc, and 10 y of calcium stearate were thoroughly mixed in a mixer. The use of expandable Boris tyreno beads and grain ah was varied as shown in Table 1. This mixture was extruded and foamed using an extruder. What is the temperature of the extruder cylinder?

Supply section 90℃, compression section front section (supply section 1 rule) 130℃.

The central part of the compression part is 135°C and the metering part is 140°C.

The die temperature was set at 130° C. at the center of the die and 120° C. at the tip of the die. The cylinder diameter was 50 mm, the screw rotation speed was 30 times/min, a circular die with an inner diameter of 50 mm was used, and the material was pressed with a sizing die (roller) to obtain a plate with a thickness of 1 m and a width of 10 (7). .

The resulting boards were colored to give a wood appearance when grain husks were used.

Table 1 Blend The results of measuring the bending strength and density of the plate obtained above are shown in FIG. In Figure 1, ■ indicates the bending strength of the example.
indicates the bending strength of the comparative example, Δ indicates the density of the example, and M indicates the density of the comparative example.

Examples 7 to 12 In Example 1, instead of grain husks (A), grain f
1.The number of expandable polystyrene beads and grain shells (B) used was varied as shown in Table 2,
A plate material was manufactured according to Example 1. The obtained board material was colored and had a wood-like appearance.

The bending strength and density of the plate material obtained above are shown in FIG. 2 together with the results of Comparative Example 1. In Figure 2, (=).

Δ, . . , and Mu are the same as above.

Examples 13 to 15 Board materials were manufactured using 100 meshes or less of wheat husks by changing the blending ratio of the swelling agent and solvent styrene beads to the wheat husks as shown in Table 3. The board was colored and had a wood-like appearance.

−〇− Table 3 Formula The bending strength of the obtained plate material is indicated by * in FIG.

According to the present invention, it is possible to obtain an extruded foam whose appearance more closely resembles wood.

[Brief explanation of the drawing]

Figure 1 is a graph showing the bending strength and density of the plates obtained in Examples 7 to 12 and Comparative Example 1, and Figure 2 is a graph showing the bending strength and density of the plates obtained in Examples 7 to 12 and Comparative Example 1. In addition, the curves of the pseudophases obtained in Examples 13 to 15 are 10-

Claims (1)

[Claims] 1. A method for producing an extruded foam, which comprises extruding and foaming a styrene resin and grain mixture. 2. Grain husks are styrene-based resin solvent 3. Grain husks (the ratio of Al and styrene resin fBl used is (A)
/(B) from 0.5/95.5 to 20/80 (weight