JPH0657086A - Rubber-reinforced styrenic resin composition - Google Patents

Abstract

PURPOSE:To provide a rubber-reinforced styrenic resin composition having well-balanced moldability, heat-resistance, strength and rigidity. CONSTITUTION:The rubber-reinforced styrenic resin composition is composed of a rubber-reinforced styrenic resin and a terpenic resin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a rubber-reinforced styrene resin composition containing a terpene resin in a rubber-reinforced styrene resin. More specifically, the present invention provides a rubber-reinforced styrene resin composition having an excellent balance of heat resistance, moldability, strength and rigidity.

[0002]

2. Description of the Related Art Rubber-reinforced styrene resin (HIPS resin) has been widely used as a molding material for household products, electric appliances, etc. since it is a resin excellent in moldability, strength and rigidity. Recently, due to soaring raw materials, there is a tendency to switch to other low-grade resins from other high-grade resins, and the demand for rubber-reinforced styrene-based resins is further increasing. At the same time, in order to expand the field of use and to enhance the productivity of products, there is an increasing demand for improvement in the strength and moldability of the rubber-reinforced styrene resin.

[0003]

Heretofore, in order to obtain a rubber-reinforced styrenic resin having high strength, it is necessary to increase the amount of rubber, increase the diameter of rubber particles, or increase the molecular weight of polystyrene as a continuous phase. The method of doing was used. However, such a method inevitably reduces the fluidity of the rubber-reinforced styrene resin. Further, an increase in the amount of rubber and an increase in the diameter of rubber particles lead to a decrease in the rigidity of the rubber-reinforced styrene resin and a decrease in the appearance.

Further, it is a known method to use a plasticizer in order to supplement the moldability, but the addition of the plasticizer lowers the heat resistance and rigidity and also the strength. Further, it is well known that a plasticizer, for example, a rubber-reinforced styrene resin to which white mineral oil is added causes a plasticizing agent to bleed out at the time of molding to exhibit a sweating phenomenon, resulting in a decrease in productivity and a decrease in quality of a molded product. It is a fact.

[0005]

Means for Solving the Problems In view of the present situation, the present inventors have conducted extensive studies, and as a result, by combining a terpene resin with a rubber-reinforced styrene resin, moldability, heat resistance, strength and rigidity are improved. It was found that a rubber-reinforced styrene resin composition having an excellent balance was obtained, and the present invention was completed. That is, the present invention is a rubber-reinforced styrene-based resin composition comprising a rubber-reinforced styrene-based resin and a terpene-based resin.

The present invention will be described below. The rubber-reinforced styrenic resin referred to in the present invention comprises rubber-like elastic particles as dispersed particles, and is made from styrene-based monomers such as styrene, p-methylstyrene, pt-butylstyrene and α-methylstyrene, either alone or in a mixture. It is a resin having a polymer as a continuous phase.
The production method can be carried out by a known method, for example, a method in which a rubber-like elastic material is dissolved in a styrene monomer and / or a solvent and polymerized in a reactor equipped with a stirrer.

The terpene resin is a Friedel-Crafts type catalyst (for example, aluminum chloride) containing dipentene and aromatic hydrocarbons obtained by isomerization of d-limonene obtained from citrus cortex or α-pinene obtained from raw pine resin. , Boron trifluoride, etc.).
The resin obtained by hydrogenating this polymer is also the terpene resin referred to in the present invention. There is no particular restriction on the hydrogenation rate.

Aromatic hydrocarbons include styrene and α-
Methylstyrene, vinyltoluene and the like are preferably used. The degree of polymerization of the terpene resin is not particularly limited, but the degree of polymerization is 1000 or less, preferably 500 or less, more preferably 200 or less. If the degree of polymerization exceeds 1000, the compatibility with the rubber-reinforced styrene resin is lowered, which is not preferable.

Examples of the terpene-based resin include YS resin TO-125 and TO- manufactured by Yasuhara Chemical Co., Ltd.
115, TO-105, TO-85; CLEARON M-1
15, M-105, P-125, P-115, P-10
5, P-85 and the like can be used. The content of the terpene resin is 0.530 parts by weight based on 100 parts by weight of the rubber-reinforced styrene resin. Preferably 1 to 20 parts by weight,
More preferably, it is 1 to 12 parts by weight. When the content of the terpene resin is less than 0.5 part by weight, the effects of improving fluidity and strength are not exhibited. If it exceeds 30 parts by weight, the effect is saturated and the compatibility with the rubber-reinforced styrene resin is lowered, which is not preferable. In addition, the cost is increased, which is not preferable.

The terpene-based resin may be added by dissolving it in a raw material solution prepared by dissolving a rubber-like elastic material in a styrene-based monomer and polymerizing it, or by changing the terpene-based resin to a styrene-based monomer or a solvent during the polymerization. It is possible to use a method in which the terpene resin is added after being dissolved or added, or before the unreacted styrene-based monomer, the polymerization solvent and the like are removed after the polymerization is completed.

It is also possible to mix the rubber-reinforced styrene resin and the terpene resin and knead them with an extruder or a molding machine. The rubber-reinforced styrenic resin of the present invention includes various additives that are frequently used in conventional rubber-reinforced styrenic resins, such as stearic acid, behenic acid, their metal salts (calcium, magnesium, zinc, etc.), ethylenebisstearo. An amide or the like can also be added. Further, an antioxidant, a colorant, an antistatic agent, etc. can be added.

[0012]

EXAMPLES The present invention will be described in more detail below. However,
The invention is in no way limited by these examples. (Production of rubber-reinforced styrene resin-1) 10 with stirrer
0.4 kg of rubber-like elastic material in a liter autoclave
(NF-35 from Asahi Kasei Corporation), 5 kg of styrene,
0.6 kg of ethylbenzene and 1.8 g of 1,1 bis (t-butylperoxy) cyclohexane were charged, and the temperature was 120 ° C.
After 3 hours at 130 ° C. for 2 hours and at 150 ° C. for 2 hours, unreacted styrene and ethylbenzene were recovered by an extruder to obtain a rubber-reinforced styrene resin-1.

(Production of Rubber Reinforced Styrene Resin-2) In a 10 liter autoclave equipped with a stirrer, 0.4 kg of rubber-like elastic material (NF-35 of Asahi Kasei Corporation), 4.7 kg of styrene, 0.6 kg of ethylbenzene, 1.8 g of 1,1 bis (t-butylperoxy) cyclohexane was charged, and the temperature was 125 ° C. for 3 hours, the temperature was 135 ° C. for 2 hours, and the temperature was 155 ° C.
After polymerization for 2 hours, unreacted styrene and ethylbenzene were recovered by an extruder to obtain a rubber-reinforced styrene resin-2.

[0014]

[Examples 1 to 4] 100% of rubber-reinforced styrene resin-1
2,4,6,12 parts by weight of the terpene resin was mixed per parts by weight and granulated with a 20 mm twin-screw extruder to obtain a rubber-reinforced styrene resin composition. The physical properties of the obtained composition are shown in Table 1.
Shown in. The physical properties were measured by the following methods. (1) MFR: Complies with ISO R1133. (2) VICA softening point: According to ASTM D1525. (3) Tensile strength: According to ASTM D638. (4) IZOD impact strength: According to ASTM D256. (5) Impact strength: 15 cm x 15 c with injection molding machine
Create a m × 3mm test piece, attach a cylindrical weight to the R = 3/4 inch missile, drop it from a height of 50 cm, and load at which 50% of the test piece breaks (N: Newton)
Then, the impact strength is calculated.

The terpene resin used is YS resin TO-115 manufactured by Yasuhara Chemical Co., Ltd.

[0016]

Example 5 A rubber-reinforced styrene resin composition was obtained in the same manner as in Example 1 except that 4 parts by weight of CLEARON M115 manufactured by Yasuhara Chemical Co., Ltd. was used as the terpene resin. The physical properties are shown in Table 1.

[0017]

Examples 6 to 8 A rubber-reinforced styrene-based resin composition was obtained in the same manner as in Example 1 except that the rubber-reinforced styrene-based resin-2 was used. The physical properties are shown in Table 1.

[0018]

Example 9 A rubber-reinforced styrene resin composition was obtained in the same manner as in Example 6 except that 4 parts by weight of CLEARON M115 manufactured by Yasuhara Chemical Co., Ltd. was used as the terpene resin. The physical properties are shown in Table 1.

[0019]

[Comparative Examples 1 to 3] Instead of terpene resin, mineral
A rubber-reinforced styrene resin composition was obtained in the same manner as in Examples 1 to 3 except that oil was used. Table 1 for physical properties
Shown in.

[0020]

[Comparative Examples 4 to 6] Instead of terpene resin, mineral
A rubber-reinforced styrene resin composition was obtained in the same manner as in Examples 6 to 8 except that oil was used. The physical properties are shown in Table 1.

[0021]

Comparative Examples 7 to 8 Table 1 shows the physical properties of the rubber-reinforced styrene resin-1 and the rubber-reinforced styrene resin-2.

[0022]

[Table 1]

The rubber-reinforced styrene-based resin composition of the present invention has almost no change in heat resistance and rigidity, and as shown in FIGS. 1 and 2, mineral-added rubber-reinforced styrene-based resin composition. It has a better balance of fluidity and strength.

[0024]

The rubber-reinforced styrene-based resin composition of the present invention has a remarkably excellent balance of moldability, heat resistance, strength and rigidity, as compared with the rubber-reinforced styrene-based resin composition containing a plasticizer which has been frequently used. .

[Brief description of drawings]

FIG. 1 shows MFR and I of a rubber-reinforced styrene resin composition of the present invention and a conventional rubber-reinforced styrene resin composition.
The relationship with ZOD IMPACT is shown.

FIG. 2 shows the relationship between MFR and one-shot impact strength for a rubber-reinforced styrene-based resin composition of the present invention and a conventional rubber-reinforced styrene-based resin composition.

Claims (1)

[Claims] 1. A rubber-reinforced styrene-based resin composition comprising a rubber-reinforced styrene-based resin and a terpene-based resin.