WO1998033853A1

WO1998033853A1 - Polystyrenic resin composition, anti-flame composition thereof and methods for the preparation thereof

Info

Publication number: WO1998033853A1
Application number: PCT/KR1997/000137
Authority: WO
Inventors: Young Chul Ha; Dong Kwon Jung; Kyoung Bae Park; Cheol Rim Choi; Yoon Kyu Kim; Sang Wook Park
Original assignee: Dongbu Hannong Chemical Co., Ltd.
Priority date: 1997-01-31
Filing date: 1997-07-11
Publication date: 1998-08-06
Also published as: KR100220617B1; KR19980069770A

Abstract

A polystyrenic resin composition comprising; (A) 30 ∩ 96 wt.% of homo- or co-polymer of styrene and styrene derivatives and/or rubber modified resin thereof; (B) 3.8 ∩ 55 wt.% of a modified olefin copolymer or a mixture of the modified copolymer and other olefin polymers; (C) 0.2 ∩ 15 wt.% of block copolymer of polystyrene and polyolefin, wherein one or more polystyrene block is separated by one or more polyolefin block; and optionally (D) one or more additives selected from the group consisting of anti-flame agents, lubricants, heat resistance improvers, plasticizers, light stabilizers, antioxidants, mold release agents, anti-static agents, conductive additives, impact reinforcing agents, colorants, glass fiber, foaming agents, organic or inorganic fillers.

Description

POLYSTYRENIC RESIN C OMPOSITION.

ANTI-FLAME C OMPOSITION THEREOF

AND METHODS FOR THE PREPARATION THEREOF

Field of the Invention

The present invention relates to a highly functional polystyrenic resin composition, a anti-flame composition thereof and a methods for the preparation thereof. More particularly, the present invention relates to a resin composition comprising homo- or co-polymer of styrene and styrene derivatives and/or rubber modified resin thereof, and modified polyolefin, having excellently balanced properties between stiffness or rigidity and toughness, good resistance to weathering, gloss and chemical resistance, to a anti-flame composition having anti-flammability as well without deteriorating physical properties of the basic composition, and to methods for the preparation thereof.

Background Art

Since thermoplastic polystyrene resin has good processibility, it has been used widely in various industrial fields such as daily necessities, electronics and electric appliances, packaging materials, building materials, etc. Such polystyrene resin includes general purpose polystyrene (GPPS) having good transparency and rigidity, high-impact polystyrene (HIPS) produced to make up for the brittleness of GPPS by adding elastomers such as polybutadiene, styrene-butadiene copolymer rubber, and styrenic resins such as SMA, SAN, ABS,

ABS/PC, ABS/PVC, AES, AAS, etc., each being equiped with other required properties through copolymerization and/or blending. Generally, polystyrene resin refers to general purpose polystyrene (GPPS) and high-impact polystyrene (HIPS). While GPPS has moderate tensile strength but very low impact strength, HIPS has improved impact strength. Such improvement in impact strength, however, sacrifices physical properties such as rigidity, gloss etc., and elastomers and impurities added thereto cause structural deformation, deterioration of other physical properties and yellow change by UV light. Therefore, the application thereof is significantly limited. Several methods have been developed to solve the problem: modifying the structure of main chain and elastomers added thereto, introducing various additives such as UV stabilizers, antioxidants, whiteness improving agents etc., forming copolymer resin with second or third monomers, or blending together with polyolefin, enpra resin etc. To improve gloss, the size of dispersed particles was minimized by selecting type of elastomers added and controlling process variables, etc. In most cases, however, desired balanced physical properties have not been achieved. In case where the physical properties are balanced to some extent, it cannot be manufactured and marketed at a commercially acceptable price.

For example, polystyrene prepared by polymerizing styrene monomer in the presence of an EPDM (ethylene-propylene-diene terpolymer) rubber to improve resistance to weathering and tenacity did not show satisfactory properties as expected due to small graft bonding between EPDM rubber and polystyrene chain. Furthermore, dispersed particles therein become bigger (10 ~ 20 m) and make the surface dull and less glossy. Such approaches as blending or, during the polymerization, adding various structures of styrene-butadiene copolymers wherein butadiene double bonds are hydrogenated completely or partially in order to improve impact strength and other physical properties [EP 4,685; 250,970; DE 2,839,357; US 3,810,957 etc.] are not very effective in terms of cost and processibility, because styrene-butadiene copolymer, which is quite expensive, should be added in large amounts to ensure desired impact strength, and tensile strength and other physical properties drop in proportion to the increase of impact strength.

In other approaches, polyolefins such as polyethylene or polypropylene are blended with polystyrene in the presence of compatibilizing agent. (US 3,810, 957; 4,429,323; 4,560,727; 5,278,232; 5,344,869; EP 60, 524; 125,227; 310,015; 329,283; 402,340; 421 ,359; DE 2,839,357 etc.) The main purpose of these methods is to improve overall physical properties of the resulting blends along with resistance to weathering. The improvement, however, is not so well balanced that increase in impact strength often accompanies decrease in rigidity, and it is not easy to control the gloss or the melt flow rate of the blends. Furthermore, the physical properties are not stable upon introducing other special additives, which limits various application of the blends. Considering such deterioration of physical properties, most of the blends have been developed as film/sheet (US 902,718; 5,344,714; 5,258,463 etc.) or as adhesive. Molding products made of these blends (US 4,560,727; 5,278,232; 5,344,869 etc.) show significantly lowered mechanical strength, i.e. tensile strength and flexural strength (Yield Stress of the blend is 1 1.5 to 26.9 N/mm², while that of polystyrene itself is 25 to 55 N/mm²), little increase in impact strength, and there are no characteristics such as gloss, anti-flammability, etc. In the history of development of the polystyrenic resin composition, general purpose polystyrene (GPPS), which is transparent, glossy and has good rigidity but low impact strength, has been changed to opaque high impact polystyrene (HIPS) having improved impact resistance and elastic property provided by adding elastomers such as various rubbers, which is still not sufficient in resistance to weathering, rigidity and gloss. To overcome the drawbacks in high impact polystyrene such as loss of transparency, low rigidity and low resistance to heat and weathering, several methods have been proposed: reducing the diameter or the content of dispersed particles to improve gloss; introducing monomer for copolymerization such as MMA, BA to improve transparency; introducing other specific elastomers or blending with polyolefin derivatives in the presence of various compatability agent to improve rigidity or resistance to weathering. However, none of the methods can make satisfactory and commercially available processes to effectively overcome the shortcomings without deteriorating well established other physical properties thereof until now.

Therefore, there have been needs for polystyrenic resin compositions having both the rigidity of general purpose polystyrene and the impact resistance of high impact polystyrene at the same time, said resin composition being easily processed and handled, controllable in other specific physical properties such as gloss, weatherability, chemical resistance and flammability with little or no dropping other good physical properties, which often occurred in prior methods, and still remaining competitive in manufacturing cost that it could be commercialized.

Under the circumstances, the inventors have investigated various combinations of matrix phase, dispersion phase and compatibility agent, and prepared low price blends of polystyrenic resin composition having effectively dispersed phase and high stability, by using dispersion phase of modified polyolefin copolymer produced in the presence of metallocene catalyst, compatibility agents comprising a certain amount of styrene-olefin block copolymer and suitable polystyrene resin matrix phase. The inventors also found that the polystyrenic resin composition having substantially same physical properties can be prepared through mass or mass-suspension polymerization by using conventional facilities which have been used for manufacturing HIPS . Further, the inventors found that adding various additives such as anti-flame agent to the composition hardly deteriorates other physical properties thereof, and the resulting anti-flame composition showed even better physical properties than ABS resin.

Brief Description of the Drawings Figure 1 shows the change of Izod impact strength of the composition according to the present invention and conventional resin with the lapse of time; and

Figure 2 shows the change of tensile impact strength of the composition according to the present invention and conventional resin with the lapse of time.

Disclosure of the Invention

Therefore, it is an object of the present invention to provide a highly functional polystyrenic resin composition solving the problems of conventional polystyrene resin and the improvement thereof, having remarkably balanced rigidity and impact resistance, excellent resistance to weathering and high gloss, which are controllable, being easily processed, handled and equipped with additional characteristics such as anti-flam m ability, etc., and methods for the preparation thereof

Another object of the present invention, is to provide a polystyrenic resin composition having anti-flame characteristic as well as other good physical properties described above and methods for the preparation thereof. Further, the object of the present invention is to use a polystyrenic resin composition according to the invention to manufacture various molding products in a cost effective way, replacing ABS or blends thereof which have been used in the fields where conventional general purpose polystyrene and high impact polystyrene could not make use. Thus, in the first aspect of the invention, there is provided a polystyrenic resin composition comprising; (A) 30 — 96 wt% of homo- or co-polymer of styrene and styrene derivatives and/or rubber modified resin thereof; (B) 3.8 — 55 wt% of a modified olefin copolymer produced in the presence of metallocene catalyst, or a mixture of the modified copolymer and other olefin polymers; (C) 0.2 — 15 wt% of block copolymer of polystyrene and polyolefin, wherein one or more polystyrene block is separated by one or more polyolefin block.

Besides (A), (B) and (C), the polystyrenic resin composition of the second aspect of the invention further comprises (D) one or more additives selected from the group consisting of anti-flame agents, lubricants, heat resistance improvers, plasticizers, light stabilizers, antioxidants, mold release agents, anti-static agents, conductive additives, impact reinforcing agents, colorants such as dyes and pigments, glass fiber, foaming agents, organic or inorganic fillers.

In the third aspect of the invention, there is provided a method for preparing blends of the polystyrenic resin composition comprising said (A), (B) and (C) components and optionally one or more additives of (D) by using a known melting extruder. In the forth aspect, there is provided a method for preparing polymerized reaction products of the polystyrenic resin composition comprising said (A), (B) and (C) components and/or optionally one or more additives of (D) by using known polymerizing facilities. In the fifth aspect, there are provided various molding products such as injection molding products, extrusion molding products made of the polystyrenic resin composition.

Suitable polystyrene of the invention includes homo- or co-polymer of styrene and styrene derivatives, and/or rubber modified resin thereof, having average molecular weight of from 100,000 to 500,000, preferably from 150,000 to 350,000. The amount of polystyrene in the composition is preferably from 30 to 96 wt% , more preferably from 60 to 85 wt% .

As a dispersion phase, a modified olefin copolymer prepared through polymerization using metallocene based single site catalyst, having general formula (I) :

-τ CH₂— CH+_m-pCH₂— CH+n (I)

X Y wherein n and m are integers of from 1 to 500,

X is hydrogen, aromatic or aliphatic hydrocarbon, or copolymer thereof having from C l to C950, Y is (CH₂)_WCH₃, is an integer of from 0 to 1000. or a mixture of the modified copolymer and other olefin polymers is used in an amount of 3.8 — 55 wt% , preferably 7 — 30 wt% . The average molecular weight is from 40,000 to 300,000.

The other olefin copolymers to be mixed with the modified olefin copolymer may be, for example, polyethylene (HDPE, LDPE, LLDPE, VLDPE, ULDPE etc.), polypropylene, ethyl-vinyl based copolymer (EVA), polyethylene-propylene (EPM) and polyethylene-propylene-diene copolymer (EPDM), and acryl based copolymer (EAA), etc. The copolymer of ethylene and other alkene compound produced in the presence of metallocene catalyst, containing alkene from 5 to 50 wt% is most preferable.

Styrene-olefin block copolymer is added as compatibility agent, and has one or more polystyrene block(S) separated by one or more polyolefin block(O). Suitable block copolymers have general formulae (II) or (III):

S i— O i— (S₂)„ (II) wherein n is 0 or 1 ,

S t— O i— O₂— (S₂)_m (III) wherein m is an integer not less than 0.

The polystyrene block is 13 — 70 wt% of the total block copolymer, and molecular weight thereof is from 5,000 to 500,000. Block copolymers represented by general formulae (Ilia) or (Illb) are particularly preferable.

S_m-f-E„— B_w^-yS_x (Illb) wherein S is polystyrene block, EP is polyethylene-polypropylene block, EB is polyethylene-polybutylene block, m is from 30 to 350, n and w are independently from 200 to 900, x is from 0 to 350, and y is an integer of from 1 to 100. The content of polystyrene block is 13 — 70 wt% in each case. The amount of styrene-olefin block copolymer is 0.2- 15 wt% , preferably 2 — 10 wt% by the total composition.

Various additives can be added to polystyrenic resin composition according to the invention without dropping impact strength, tensile strength and other physical properties of the basic composition. Such additives include anti-flame agents, lubricants, heat resistance improvers, plasticizers, light stabilizers, antioxidants, mold release agent, anti-static agents, conductive additives, impact reinforcing agents, colorants such as dyes and pigments, glass fiber, foaming agents, organic or inorganic fillers. Anti-flame agents, even added in a large amount, do not cause any substantial deterioration of physical properties. The anti-flame agents may be added up to 5 — 35 wt% , depending on anti-flam m ability required in the final molding products. The term "anti-flame agent" used herein has the widest meaning including anti-flame supporting agents such as antimony trioxide, chlorinated polyethylene, as well as halogen-based and non-halogen-based anti-flame agent.

Blends of the polystyrenic resin composition according to the present invention can be prepared by mixing the components in a mixing device equipped with rotating means, such as ribbon blender, V-shaped blender and Henchel mixer under the condition of hundreds or thousands rpm at room temperature, and then melt-extruding by using a melting extruder such as conventional extruder, Brabender plasticorder, Banbury mixer, mixing roll, kneader, etc. Preferably, the melt-extruding is carried out at 170 — 260 °C , and rotating velocity of screw is 180 — 350rpm.

The polystyrenic resin composition of the invention may be prepared by using polymerization facilities conventionally employed in manufacturing polystyrene-based resin. In this case, the mixture of styrene and/or the derivatives thereof, if necessary, other monomers which may be incorporated into copolymer, modified polyolefins, rubbers, additives, etc is subjected to mass or mass-suspension polymerization as in HIPS production.

The physical properties of resulting polymerization products are substantially same with those of blending products, and may be controlled as in HIPS production. Thus, the physical properties of the final products vary depending on property control of HIPS such as the average molecular weight of matrix phase PS, existence of initiator, type and amount of additives, stirring speed in processing steps, etc. Therefore, general factors relating to conventional HIPS production may be considered in polymerization of the composition according to the invention.

The polystyrenic resin composition of the present invention may be injection molded to injection molding products, being anti-flame or not, or extrusion molded with suitable additives to extrusion molding products such as film, sheet, etc.

The following non-limiting examples are given to illustrate the present invention.

EXAMPLE 1

The following components are used for the preparation of blends of polystyrenic resin composition (DH 1 — DH22) in amounts as indicated in Table la :

Component (A) : Solarene polystyrene grade, pellet type Component (B) : polyolefin copolymer grade modified by metallocene based single site catalyst Component (C) : Styrene-poly(ethylene-propylene)-styrene block copolymer and

Styrene-poly(ethylene-butylene)-styrene block copolymer The components were mechanically mixed in a Henchel mixer at a room temperature, under 1000 rpm for 5 minutes. Then, the mixture was melt and mixed in a twin-screw extruder (L/D=25) at a temperature ranging from 170 to 250 °C under 200 to 300 rpm of the screw, pelletized in a strand cutting way. To measure mechanical properties thereof, test samples were prepared from the resulting polystyrene blends by using a injection molding machine under the conditions as follows: Temperature of the injection molding machine = 210 T ; Temperature of the metallic mold = 50 °C ; Molding cycle = 35 sec.

Tensile strength, Izod impact strength and flexural strength of each test sample were measured in accordance with ASTM D638 and ASTM D256. Measurement of gloss was effected on a test sample of 56.0mm in diameter and 1.6mm in thickness in accordance with ASTM D523 by using Gloss meter (angle of incident = 60° ) The results are shown in Table 1. Table 1A

Table IB

Table IC

Table ID

A l , A2, A3 : Polymer of styrene monomer

Dongbu Hannong Chemical Co., Ltd., Solarene® GPPS grade 144, 126, 1 16

A4, A5, A6 : Copolymer of styrene monomer and rubber Dongbu Hannong Chemical Co., Ltd., Solarene® HIPS grade 616, 724, 334

B l , B2, B3 : metallocene-based polyethylene octene copolymer Engage grade (Dupont Dow), Densities are 0.870, 0.868, 0.902, respectively

B4 : metallocene-based polyethylene hexene copolymer Exact grade (Exxon), density is 0.880

B5, B6, B7 : metallocene-based alpha-olefin copolymer

Tafmer grade (Mitsui sekiyu Kagaku, Japan), A0586X, PO480, PO775 grade, respectively

B8 : EPDM 520P (Kumho Petrochemical) grade

B9 : metallocene based EPDM Elastomer Nodel IP® 4725P grade (Dupont Dow) C l , C2, C3 : styrene-ethylene-propylene or styrene-ethylene-propylene-styrene block copolymer content of styrene is 35, 65, 13 wt% , respectively (Kuraray, Septon®) C l , C2, C3 : styrene-ethylene-propylene-styrene block copolymer melt flow indexes are 3.5, 0.7, 9.5g/10min, respectively (Asahi, Tuftec ) D I , D2, D3 : Impact modifier (Rubber or elastomer), styrene-butadiene copolymer, T-168 (Enichem, Europrene®), Tufprene 125 (Asahi), Stereon 840A

(Firestone) grade 1 ,2 : Polymer of styrene monomer

Jeil Industries Inc. (Korea) HF-2660 grade and Asahi Chem. (Japan) 666R grade 3,4 : Copolymer of styrene monomer and rubber,

Jeil Worsted (Korea) HR-1360 grade and Hyosung BASF (Korea) 432 grade 5,6 : ABS(Acrylonitrile-butadiene-styrene) ter-polymer LG Chem. (Korea) HF380 grade and Hyosung BASF (Korea) 857N grade

7,8 : Blends of linear low density polyethylene(LLDPE) and polystyrene (KR Patent 95-2888)

EXAMPLE 2

Anti-flame agents (D) are further added to the composition of Example 1 as shown in Table 2 and test samples were prepared according to the process of Example 1. Halogen-based and non-halogen-based anti-flame agents, and anti-flame supporting agents such as antimony trioxide, chlorinated polyethylene are used herein as the components (D).

Flammability and other physical properties of the test samples were measured and shown in Table 2. Table 2 shows that impact strength and tensile strength are not dropped by adding the anti-flame agents. Table 2A

Table 2B

D4, D6, D7 : Halogen-based anti-flame agent

Brome contents are 67.2, 83, 69.5 - 70.5% , respectively (Albemarle, Saytex®) D5 : Brome-based low toxic anti-flame agent S8010 Grade

(Albemarle, Saytex ) D8 : Halogen-based anti-flame agent

Brome content is 66 — 68% (Flamecut 121k) D9 : Chlorinated polyethylene (CPE) D 10 : Antimony trioxide(Sb₂O₃)

EXAMPLE 3

Styrenes were subjected to mass polymerization in the presence of components (B), (C) and (D) by using conventional HIPS polymerization facilities. The overall characteristics containing average molecular weight, melt flow rate, etc., of the matrix polystyrene were controlled just as each Solarene GPPS grade. From the resulting products [the compostions thereof are shown in Table 1 ; DH23, DH24, DH25], test samples were prepared and the mechanical properties thereof were measured according to the process of Example 1. The results are shown in Table 1 (DH23, DH24, DH25).

Therefore, the polystyrenic resin composition according to the invention can be prepared by using conventional polystyrene polymerization facilities as well as melting extruder.

COMPARATIVE EXAMPLE

Blends of

Component (A) : Solarene polystyrene grade (Dongbu Hannong

Chemical Co., Ltd, Korea), pellet type Component (B) : A high density polyethylene (HDPE) and a linear low density polyethylene(LLDPE); and Component (C) : Olefin grafted polystyrene copolymer shown in Table 3 were prepared and the physical properties thereof were measured according to the process of Example 1. The results are shown in Table 3. In contrast to the blends of the present invention, the blends of the comparative examples did not show balanced physical properties. Table 3A

Table 3B

A l , A2 : Polymer of styrene monomer,

Dongbu Hannong Chemical Co., Ltd., Solarene® GPPS grade 144, 126 A3 : Copolymer of styrene monomer and rubber Dongbu Hannong Chemical Co., Ltd., Solarene® HIPS grade 616 B l : High density polyethylene(HDPE),

Korea Petrochemical Ind., Co., Ltd., E308 grade, density 0.956 B2 : Linear low density polyethylene(LLDPE) Hyundai Petrochemical Co., Ltd.

SF318 grade, density 0.920 C l : low density polyethylene grafted polystyrene (LDPE-g-PS,70/30 wt% ) (Japan oil and fat) C2 : polypropylene grafted polystyrene (PP-g-PS, 70/30 wt% )

(Japan oil and fat) C3 : ethyleneglycol metacrylate grafted polystyrene (EGMA-g-PS, 70/30 wt% ) (Japan oil and fat)

PHYSICAL PROPERTY TEST

The resistance to weathering of the samples prepared in Example 1 (DH4, DH9, DH 12) is evaluated. The test was carried out according to ASTM D 1435-85 through outdoor exposure in 15 weeks, and the change of impact strength and tensile strength in ABS, HIPS and the test samples of Example 1 were measured and shown in Figs. 1 and 2. The ABS test sample was HF 380 grade (Kumho Chem., Korea), and the HIPS test sample was Solarene H724 grade (Dongbu Hannong Chemical Co., Ltd.).

Claims

What is claimed is:

1. A polystyrenic resin composition comprising;

(A) 30 ΓÇö 96 wt% of homo- or co-polymer of styrene and styrene derivatives and/or rubber modified resin thereof; (B) 3.8 ΓÇö 55 wt% of a modified olefin copolymer or a mixture of the modified copolymer and other olefin polymers; and

(C) 0.2 ΓÇö 15 wt% of block copolymer of polystyrene and polyolefin, wherein one or more polystyrene block is separated by one or more polyolefin block.

2. The polystyrenic resin composition according to claim 1 further comprising (D) one or more additives selected from the group consisting of anti-flame agents, lubricants, heat resistance improvers, plasticizers, light stabilizers, antioxidants, mold release agents, anti-static agents, conductive additives, impact reinforcing agents, colorants, glass fiber, foaming agents, organic or inorganic fillers.

3. The polystyrenic resin composition according to claim 1 wherein the component (C) is replaced with one or more additives selected from the group consisting of anti-flame agents, lubricants, heat resistance improvers, plasticizers, light stabilizers, antioxidants, mold release agents, anti-static agents, conductive additives, impact reinforcing agents, colorants, glass fiber, foaming agents, organic or inorganic fillers.

4. The polystyrenic resin composition according to any one of claims 1 to 3, wherein said modified olefin copolymer is prepared through polymerization using metallocene based single site catalyst, and has general formula (I) :

-╧ä>CH₂ΓÇö CH-╧ä-_m- CH₂ΓÇö CH-hn (I)

X Y wherein n and m are integers of from 1 to 500,

X is hydrogen, aromatic or aliphatic hydrocarbon, or copolymer thereof having from C l to C950,

W is an integer of from 0 to 1000 with the average molecular weight being from 40,000 to 300,000.

5. The polystyrenic resin composition according to claim 1 , wherein said modified olefin copolymer is a polymer prepared by polymerizing ethylene and other alkene compounds using metallocene based single site catalyst.

6. The polystyrenic resin composition according to any one of claims 1 to 3, wherein said other olefin polymers are selected from the group consisting of polyethylene, polypropylene, ethyl-vinyl based copolymer, polyethylene-propylene and polyethylene-propylene-diene copolymer, and acryl based copolymer.

7. The polystyrenic resin composition according to claims 1 or 2, wherein said block copolymer has general formulae (II) or (III)

S iΓÇö O iΓÇö O₂ΓÇö (S₂)_m (III) wherein

S is polystyrene block, O is olefin block, m is an integer not less than 0, and n is 0 or 1.

8. The polystyrenic resin composition according to claim 7, wherein said polystyrene block is 13 ΓÇö 70 wt% of the total block copolymer.

9. The polystyrenic resin composition according to claims 1 or 2, wherein said block copolymer has general formulae (Ilia) or (Illb)

wherein

S is polystyrene block, EP is polyethylene-polypropylene block, EB is polyethylene-polybutylene block, m is from 30 to 350, n and w are independently from 200 to 900, x is from 0 to 350, and y is an integer of from 1 to 100.

10. The polystyrenic resin composition according to claim 9, wherein said polystyrene block is 13 ΓÇö 70 wt% of the total block copolymer.

1 1. A method for preparing the polystyrenic resin composition according to claims 1 or 2, characterized in that all components are blended by using conventional melting extruder.

12. A method for preparing the polystyrenic resin composition according to any one of claims 1 to 3, characterized in that the mixture of styrene and/or the derivatives thereof, optionally other monomers are subject to mass or mass-suspension polymerization together with (B) and, (C) and/or (D) components by using conventional HIPS polymerization facilities.

13. A molding product made of the polystyrenic resin composition according to anyone of the preceding claims.