JPH0570645A - Resin composition and its production - Google Patents

Abstract

PURPOSE:To obtain a resin composition having excellent moldability, flame- retardancy, etc., by mixing an acrylonitrile-styrene copolymer, a fluorinated polyethylene and an organic peroxide, heat-treating the mixture at a specific temperature and mixing a polyvinyl chloride resin to the product. CONSTITUTION:The objective composition having well balanced heat-stability impact resistance and rigidity is produced by mixing (A) an acrylonitrile-styrene copolymer, (B) a chlorinated polyethylene having a chlorine content of 10-45%, (C) an organic peroxide having 10min half-life temperature (Thalf) of >=90 deg.C (e.g. lauroyl peroxide) and (D) an antimony oxide such as antimony trioxide, heat-treating the mixture at a temperature above Thalf and not higher than Thalf+30 deg.C and mixing (E) a polyvinyl chloride resin such as vinyl chloride- ethylene copolymer to the heat-treated mixture.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a flame-retardant styrene resin. More specifically, the present invention relates to a resin composition having excellent moldability, flame retardancy, thermal stability, impact resistance and rigidity.

[0002]

2. Description of the Related Art At present, various flame-retardant resins are used for electric appliance parts, electronic appliance parts, automobile parts, daily commodities and parts. For example, it is used for changing yokes of televisions, their back covers, word processors, various computers, facsimiles, handles for heat appliances such as irons, wiring tubes, and wallpaper. As the flame-retardant resin, a resin composition in which a halogen-based flame retardant is mixed with an impact-resistant resin such as acrylonitrile-butadiene-styrene terpolymer (ABS resin),
A resin composition comprising ABS and a polyvinyl chloride resin,
A composition in which a halogen-based flame retardant is mixed with a resin composition (modified PPO) composed of polyphenylene oxide and a polystyrene resin is widely used. However, A
In order to add a flame retardant to a BS resin, a modified PPO resin, etc. and impart a high degree of flame retardancy, a large amount of a flame retardant must be added (added). Therefore, the mechanical strength (impact strength, tensile strength, etc.) of the composition is low, and there is a problem in weather resistance. Further, a composition comprising an ABS resin and a polyvinyl chloride resin is excellent in flame retardancy and weather resistance, but has problems in thermal stability during molding, moldability, and heat resistance.

As a means for solving these problems, a polyvinyl chloride resin having improved molding heat stability and fluidity and A
Composition with BS resin (JP-A-60-208345, JP-A-63-182364) or AB
A resin composition of an S resin and a polyvinyl chloride resin having a specific composition (JP-A-62-41252) has been proposed. Further, some of the present inventors have already (A) chlorinated polyethylene having a chlorine content of 15 to 45% by weight,
A resin composition comprising (B) a polyvinyl chloride-based resin, (C) a copolymer resin of styrene and acrylonitrile, (D) a copolymer resin of α-methylstyrene and acrylonitrile, and (E) antimony oxide was proposed. Japanese Patent Application No. 2-213836).

[0004]

However, the former ABS resin-based composition can improve some of the various properties to some extent, but is not necessarily satisfactory. Further, the latter resin composition proposed by some of the inventors of the present invention is not always satisfactory in terms of the balance of moldability, impact resistance and rigidity depending on its application. In view of the above situation, it is an object of the present invention to provide a resin composition which has not only excellent flame retardancy and thermal stability but also excellent balance between impact resistance and rigidity and excellent moldability.

[0005]

The present invention provides (A) an acrylonitrile-styrene copolymer and (B) a chlorine content of 1
A composition consisting of 0 to 45% by weight of chlorinated polyethylene, (C) polyvinyl chloride resin, (D) organic peroxide and (E) antimony oxide, which are (A), (B) and (C). ) The composition ratio in the total amount of each component is (B)
The component is 1.0 to 25% by weight, and the component (C) is 5.0.
Is 50% by weight, and the composition ratio of the other components to the total 100 parts by weight of the components (A), (B) and (C) is
In producing the resin composition in which the component (D) is 0.01 to 10 parts by weight and the component (E) is 0.5 to 10 parts by weight, and at least the component (C) is removed in producing the resin composition. After the components (A), (B) and (D) are mixed and heat-treated at a temperature not lower than the 10-minute half-life of the organic peroxide and not exceeding 30 ° C. below the half-life temperature, (C) )
The present invention provides a method for producing the resin composition, which comprises mixing the components. The present invention will be specifically described below.

Component (A) Acrylonitrile-styrene copolymer (hereinafter referred to as AS resin) The AS resin used in the present invention is a copolymer of styrene and acrylonitrile. The copolymerization ratio of styrene in this copolymer is generally 40 to 90% by weight, preferably 50 to 80% by weight. The AS resin can be produced by any of the commonly used methods of aqueous suspension polymerization, emulsion polymerization, solution polymerization, and bulk polymerization, and is industrially produced and widely used. The molecular weight of the AS resin used in the present invention is usually 1,
000 to 500,000, preferably 10,000 to 300,000. When the molecular weight is 1,000 or less, impact resistance and mechanical strength are insufficient. If it is 500,000 or more, the workability is not good. The structures, manufacturing methods, and physical properties of these resins are well known.

Component (B) Chlorinated Polyethylene The chlorinated polyethylene used in the present invention is obtained by chlorinating polyethylene powder or particles described below in an aqueous suspension, or by dissolving polyethylene in an organic solvent.
It can be manufactured by chlorination. Among them, the method of chlorinating in an aqueous suspension is preferable. Chlorinated polyethylene is industrially manufactured and used in various fields, and its manufacturing method and various physical properties are well known. Polyethylene may be homopolymerized with ethylene or at most 20% by weight with ethylene (preferably 10% by weight).
It has at most 12 carbons (preferably 3% by weight or less).
It is obtained by copolymerizing (.about.8) α-olefins. The density of the polyethylene is generally 0.910 to 0.970 g / cm ³ , and particularly preferably 0.920 to 0.970 g / cm ³ .

The chlorine content of the chlorinated polyethylene used in the present invention is 15 to 45% by weight, preferably 18 to 40% by weight, more preferably 20 to 40% by weight. When the chlorine content is less than 15%, the resulting composition has poor impact resistance and flame retardancy. On the other hand, 45% by weight
If it exceeds, not only is the impact resistance poor, but there is a problem in terms of thermal stability. In addition, Mooney viscosity (ML _{1 + 4} , 1
00 ° C) is generally 30 to 150, 40 to 15
0 is preferable and 40 to 130 is particularly preferable.
When the Mooney viscosity (ML _{1 + 4} , 100 ° C.) is less than 30, the resulting composition has low mechanical strength. On the other hand, when it exceeds 150, there is a problem in moldability.

Component (C) Polyvinyl Chloride Resin Further, the polyvinyl chloride resin used in the present invention is obtained by homopolymerizing vinyl chloride or copolymerizing another kind of monomer capable of copolymerizing with vinyl chloride. It is manufactured. Representative examples of the other monomer include vinylidene chloride, ethylene, vinyl acetate, acrylonitrile, acrylic acid, methacrylic acid and maleic anhydride, and esters thereof. The copolymerization ratio of the other type of monomer is usually at most 40% by weight, and particularly preferably 30% by weight or less. These homopolymers and copolymers are generally produced by suspension polymerization, bulk polymerization or emulsion polymerization. The average degree of polymerization of the polyvinyl chloride resin of the present invention is generally 400 to 2,000 from the viewpoint of kneading properties in producing a composition, mechanical properties of the resulting composition, and thermal stability. The range of 400 to 1,800 is preferable, and the range of 400 to 1,600 is particularly preferable. If the degree of polymerization is less than 400, there is a problem in impact resistance of the resulting composition. On the other hand, when the degree of polymerization exceeds 2,000, there is a problem in moldability. These polyvinyl chloride resins are industrially manufactured and used in various fields, and their manufacturing methods and physical properties are well known.

Component (D) Organic Peroxide The organic peroxide used in the present invention includes, for example, ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxy ester, There is peroxycarbonate, which has a decomposition temperature with a half-life of 10 minutes of 90 ° C. or more, preferably 120 ° C. to 200 ° C., and particularly preferably 130 ° C. to 200 ° C.
Those having a decomposition temperature of 10 minutes half-life of less than 90 ° C. have problems in impact strength and moldability of the resulting composition. Typical examples of the organic peroxide used include, for example, lauroyl peroxide, benzoyl peroxide, 1,
1, -bis (t-butylperoxy) 3,5,5-trimethylcyclohexane, t-butylperoxybenzoate, methyl ethyl ketone peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t- Butylperoxy) hexane, di-t-butylperoxide, 2,5-dimethyl-2,5di (t-butylperoxy) hexane-3, and the like. These organic peroxides are industrially produced. It is used in various fields, and its structure, manufacturing method, physical properties, etc. are well known.

Component (E) Antimony Oxide Further, the antimony oxide used in the present invention is widely used as a flame retardant aid for chlorinated polyethylene, polyvinyl chloride resins and general bromine-containing compounds. .. Representative examples are antimony oxides such as antimony trioxide and antimony pentoxide. The average particle size of the antimony oxide is 0.3 to 150 μm.
Further, in the present invention, a dechlorination inhibitor generally used in the field of polyvinyl chloride resins and chlorinated polyethylene is blended (added) in order to improve the thermal stability of the resulting resin composition. To be done. Regarding dehydrochlorination inhibitors, as a stabilizer for vinyl chloride, “Vinyl Chloride Material Handbook” edited by the Vinyl Chloride Products Association (1966,
Published by Industrial Research Institute Co., Ltd.) pp. 171 to 282. Among these antioxidants, organotin compounds are preferable. Typical examples of the organotin compound are dibutyl tin dilaurate, dibutyl tin malate, octyl tin compound, dimethyl tin compound, dibutyl tin laurate malate complex, stannane diol derivative and mercapto.
Examples include tin compounds and mixtures containing these organotin stabilizers as main components.

(F) Composition Ratio The ratio of the chlorinated polyethylene composition ratio to the total amount of the polymeric substances comprising the AS resin, chlorinated polyethylene and polyvinyl chloride resin of the present invention is 1.0 to 25% by weight. %, Preferably from 3.0 to 22% by weight, particularly 3.0
-20% by weight is preferred. If the composition ratio of chlorinated polyethylene in the total amount of the polymer is less than 1.0% by weight, the resulting composition has poor impact resistance. On the other hand, 2
If it exceeds 5% by weight, there is a problem in rigidity and moldability of the resulting composition. In addition, the composition ratio of the polyvinyl chloride resin in the total amount of the polymer substance is 5.0 to 50% by weight.
And is preferably 5.0 to 45% by weight, particularly 5.0 to 45% by weight.
40% by weight is preferred. When the composition ratio of polyvinyl chloride in the total amount of the polymer substances is less than 5.0%, the resulting composition has insufficient impact resistance. On the other hand, when it exceeds 50% by weight, the thermal stability of the obtained composition decreases. The amount of the organic peroxide is 0.01 to 10 parts by weight, and the amount of the organic peroxide is 0.05 to 5.
0 parts by weight is preferable, and 0.1 to 2.0 parts by weight is particularly preferable. When the amount of the organic peroxide is more than 10 parts by weight based on 100 parts by weight of the total amount of the polymer substance, the composition obtained has poor moldability and impact resistance, and there is a risk of explosion and the like. Further, the amount of antimony oxide is 0.5 to 10 parts by weight, and especially 1.0 to 8 parts by weight is preferable with respect to 100 parts by weight of the total amount of the polymer substance. If the proportion of antimony oxide is less than 0.5 part by weight, there is a problem in flame retardancy. On the other hand, if the amount exceeds 10 parts by weight, the mechanical strength of the obtained composition decreases. When a dehydrochlorination inhibitor is added, its composition ratio is 1% of the total amount of the above polymeric substances.
It is at most 15 parts by weight with respect to 00 parts by weight, preferably 12 parts by weight or less, and particularly preferably 10 parts by weight or less. If the amount is more than 15 parts by weight, there is a problem in cost.

(G) Production of the composition, molding method, etc. In producing the composition of the present invention, the AS resin, chlorinated polyethylene and organic peroxide are mixed in advance to obtain a 10-minute half-life of the organic peroxide. After the heat treatment at a temperature equal to or higher than the above and not exceeding 30 ° C. from the half-life temperature, the obtained mixture is mixed with the polyvinyl chloride resin and the remaining composition components. Also, antimony oxide,
The dehydrochlorination inhibitor and the like may be compounded (added) at any stage in the production process of the composition, if necessary. The method of raising the temperature of the polymer substance to a temperature higher than the temperature of the 10-minute half-life of the organic peroxide can be achieved in a mixer described later, but it may be achieved by using an oven or the like after previously mixing at a low temperature. As a mixing method, a method of dry blending using a mixer such as a Henschel mixer which is generally used in the field of synthetic resins, and a mixer such as a tumbler mixer, an open roll, an extrusion mixer, a kneader and a Banbury are used. A method of mixing while melting is used. Among these mixing methods, in order to obtain a more uniform composition, two or more of these mixing methods may be used in combination. (For example, pre-dry blend and then melt mix the mixture). Above all, in the case of using a dry blend in combination or in the case of using one or two or more methods of melt-kneading together, in producing a molded article by the molding method described below, it should be produced into pellets by using a pelletizer and used. Is preferred. In the case of melt kneading among the above mixing methods and in the case of molding by the molding method described later, it must be carried out at a temperature at which the polymer substance used is melted. However, if it is carried out at a high temperature, the polymer substance may cause thermal decomposition or deterioration such as dehydrochlorination, so that it needs to be carried out at 220 ° C. or lower. In addition, additives such as heat, oxygen and light stabilizers, fillers, colorants, lubricants, plasticizers and antistatic agents, which are widely used in the field of synthetic resins, essentially impair the properties of the composition. You may mix (add) in the range which does not exist.

The composition of the present invention is molded into a desired shape by applying a molding method such as an injection molding method, an extrusion molding method, a compression molding method and a hollow molding method which are generally used in the field of synthetic resins. You may let me. Further, after being formed into a sheet using an extrusion molding machine, this sheet may be formed into a desired shape by a secondary processing method such as a vacuum forming method or a compression forming method.

[0015]

EXAMPLES The present invention will be described in more detail below with reference to examples. In Examples and Comparative Examples, the melt flow index (hereinafter referred to as MFR) is JIS K.
According to 7210, the temperature was 200 ° C. and the load was 5 kg. The Izod impact strength (hereinafter referred to as IZOD) was measured with a notch at a temperature of 23 ° C. according to ASTM D256. The flexural modulus is ASTM D79
According to 0, it measured at 23 degreeC. Further, the flame retardancy test was performed according to the combustion test method defined in UL Standard 94 of the United States. The thermal stability test was carried out by visually observing the appearance change after leaving the sample for 15 minutes at a pressure of 100 kg / cm ² G between the press plates set at a temperature of 220 ° C. Some are represented by Δ and those with significant changes are represented by X. Furthermore, the spiral flow is performed by an injection molding machine in which the cylinder temperature is set to 180 ° C., the shape of the spiral part of the mold is 12.7 mm × 3.7 mm thick, the mold temperature is 50 ° C., and the injection pressure is 90 kg / c
It was measured with an m ² gauge. In addition, the AS resin, chlorinated polyethylene, polyvinyl chloride resin, organic peroxide and antimony oxide, and the method for producing the dehydrochlorination inhibitor used in Examples and Comparative Examples are described below.

(A) AS Resin As AS resin, the copolymerization ratio of acrylonitrile is 23
An acrylonitrile-styrene copolymer having a weight average molecular weight of 120,000 was used.

(B) Chlorinated Polyethylene As chlorinated polyethylene, ethylene having a copolymerization ratio of butene-1 of 3.0% by weight, a density of 0.940 g / cm 3 and an average molecular weight of about 150,000. Butene-1
Residual crystals of polyethylene produced by chlorinating the copolymer in an aqueous suspension, having a chlorine content of 30.5% by weight, a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 110. Chlorinated polyethylene (hereinafter referred to as "CPE") having an amount of 7.15% by weight was used.

(C) Polyvinyl chloride resin Further, as the polyvinyl chloride resin, the copolymerization ratio of ethylene is 1.5% by weight and the average degree of polymerization is about 65.
0 vinyl chloride-ethylene copolymer (hereinafter referred to as "PV
C ") was used.

(D) Organic peroxide Further, as the organic peroxide, the 10-minute half-life temperature is 93.
Lauroyl peroxide (hereinafter referred to as "PO-1")
Dicumyl peroxide having a 10-minute half-life temperature of 149 ° C. (hereinafter referred to as “PO-2”) and 10
2,5-dimethyl-2, which has a minute half-life temperature of 154 ° C.
5, di (t-butylperoxy) hexane (hereinafter "PO
-3 ”) was used.

(E) Antimony Oxide Antimony trioxide (hereinafter referred to as "Sb ₂ O ₃ ") was used as antimony oxide.

(F) Dehydrochlorination inhibitor As a dehydrochlorination inhibitor, dibutyl tin malate (hereinafter referred to as "StBM") was used.

Example 1 Each composition component (AS resin, CPE, organic peroxide, Sb ₂ O) except PVC whose kind and blending amount are shown in Table 1 is shown.
₃ and a dehydrochlorination inhibitor) were dry-blended with a Henschel mixer for 5 minutes and then heat-treated at 100 ° C. for 10 minutes, and a predetermined amount of PVC was added (added) to the obtained mixture. After that, the mixture was dry-blended again with a Henschel mixer, and a single screw extruder with a vent (diameter 40
mm), and pelletized the composition using a pelletizer.

Example 2 Pellets were produced in the same manner as in Example 1 except that 0.5 part by weight of PO-2 was used as the organic peroxide and the heat treatment was carried out at 160 ° C. for 10 minutes.

Examples 3 to 5 Pellets were produced in the same manner as in Example 1 except that PO-3 was used as the organic peroxide and the heat treatment was performed at 180 ° C. for 10 minutes.

Example 6 A mixture containing each composition component except PVC was dry blended for 5 minutes using a Henschel mixer, and then a vented single-screw extruder (diameter 40 mm) in which the cylinder temperature was set to 180 ° C. The mixture was kneaded by using a pelletizer and mixed with a pelletizer in a predetermined amount of PVC, and the mixture was dry-blended with a tumbler mixer. The mixture was again mixed with a ventilated single-screw extruder (cylinder temperature was set to 180 ° C). (Diameter 40 mm) was used for kneading, and pellets of the composition were obtained using a pelletizer.

Comparative Example 1 Pellets were produced in the same manner as in Example 3 except that all the composition components (AS resin, CPE, PVC, organic peroxide, Sb ₂ O ₃ and dehydrochlorination inhibitor) were simultaneously added. did.

Comparative Example 2 Pellets were produced in the same manner as in Example 3 except that the organic peroxide was not added (added).

Comparative Example 3 Pellets were produced in the same manner as in Example 3 except that the heat treatment temperature was 160 ° C.

Comparative Example 4 Pellets were produced in the same manner as in Example 3 except that the heat treatment temperature was 220 ° C.

The MFR of each obtained pellet was measured.
The results are shown in Table 2. Further, each pellet was injection-molded to prepare a test piece (thickness: 1.6 mm) for IZOD (with notch), bending strength and flame retardancy test. The results of measuring them are shown in Table 2. Table 2 shows the results of thermal stability evaluation and fluidity evaluation by spiral flow.
Shown in.

[0031]

[Table 1]

[0032]

[Table 2]

From the results of the above Examples and Comparative Examples, the resin composition obtained by the present invention is not only excellent in flame retardancy but also excellent in impact resistance and thermal stability, and particularly good in moldability. Moreover, it is clear that the balance between impact resistance and rigidity is also excellent.

[0034]

The composition obtained by the present invention is not only excellent in flame retardancy, impact resistance, thermal stability, moldability and balance between impact resistance and rigidity, but also exhibits the following effects. It is a composition. 1) It is excellent in mold release. 2) There is little contamination during continuous molding. 3) There is little discoloration in the injection molding of large molded products and thin molded products. 4) Good surface scratch resistance. 5) Good heat resistance. 6) Resin exchange molding is easy. The resin composition obtained by the present invention can be used in various fields as described below in order to exert good effects as described above. 1) Television, especially large television receiver housing 2) Computer equipment housing 3) Electric and electronic equipment such as facsimile and audio equipment 4) Home appliance housing

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08L 27/06 LEQ 9166-4J LER 9166-4J LEW 9166-4J 33/20 LJN 7921-4J (72 ) Inventor Mitsunobu Machida 3-2, Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Awakawa Electric Co., Ltd. Kawasaki Plastics Research Laboratory (72) Kenji Takemura 3-2, Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Sho-wa Denko Co., Ltd. Kawasaki Plastic Research Institute

Claims (2)

[Claims] 1. An (A) acrylonitrile-styrene copolymer, (B) a chlorinated polyethylene having a chlorine content of 10 to 45% by weight, (C) a polyvinyl chloride resin, (D).
A composition comprising an organic peroxide having a 10-minute half-life temperature of 90 ° C. or higher and (E) antimony oxide, (A),
The composition ratio of the total amount of each of the components (B) and (C) is 1.0 to 25% by weight for the component (B), 5.0 to 50% by weight for the component (C), and ), (B) and (C), the composition ratio of the other components to the total of 100 parts by weight is 0.01 to 10 parts by weight of the (D) component,
A resin composition in which the component (E) is 0.5 to 10 parts by weight. 2. Excluding at least component (C) (A),
The components (B) and (D) are mixed to form an organic peroxide 10
2. The method for producing a resin composition according to claim 1, wherein the component (C) is mixed after heat treatment at a temperature not lower than the half-life temperature and not higher than 30 ° C. from the half-life temperature.