JPH1180565A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic resin composition excellent in thermal melt-molding processability, and a vinyl chloride resin composition using the same. SOLUTION: This thermoplastic resin composition is obtained by mixing (A) 0.1-50 wt.% of a (co)polymer with (B) 99.9-50 wt.% of another thermoplastic polymer in a latex state and subsequently coagulating the mixture. The (co)polymer is obtained by (co)polymerizing an aromatic vinyl compound with a vinyl cyanide compound and, if necessary, at least one kind of monomer selected from the group of other vinylic monomers capable of being copolymerized with the above compounds, and has an intrinsic viscosity of >=1.5 dl/g and a weight-average mol.wt./number-average mol.wt. ratio of >3.0. A vinyl chloride resin composition contains 0.5-60 wt.% of the thermoplastic resin composition and 99.5-40 wt.% of a vinyl chloride resin as main components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition excellent in heat-melt moldability and a vinyl chloride resin composition using the same.

[0002]

2. Description of the Related Art A conjugated diene rubber is used as a base rubber.
Rubber-reinforced thermoplastic resins obtained by graft polymerization of styrene, acrylonitrile, methyl methacrylate, etc. are known as ABS resins, HIPS resins, MBS resins, etc., and have physical, chemical, mechanical and electrical properties. Because of their excellent properties, molded products are obtained by various molding methods and used in a wide range of fields.

However, when a molded article is obtained by various molding methods using the above-mentioned rubber-reinforced thermoplastic resin, there is a drawback that a molding process-suitable region is narrow depending on a shape, a molding method, and the like. For example, at the time of injection molding, a flow mark or the like is easily generated. Also, in sheet extrusion molding, die lines and eye burrs are likely to occur. Further, at the time of foam extrusion molding, the expansion ratio is hardly increased. Further, at the time of blow molding, problems such as a large drawdown, a failure in blow molding, and a large uneven thickness occur. In some cases, the rubber-reinforced thermoplastic resin is added to the vinyl chloride resin, but the modifying effect cannot be sufficiently exhibited due to poor dispersion.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and is directed to a thermoplastic resin composition excellent in heat-melt moldability and a vinyl chloride resin composition using the same. The purpose is to provide things.

[0005]

The present invention relates to (A) an aromatic vinyl compound, a vinyl cyanide compound and, if necessary, a group of other vinyl monomers copolymerizable therewith. Mw / Mn by gel permeation chromatography (GPC) wherein intrinsic viscosity is at least 1.5 dl / g (where Mw is the weight average molecular weight in terms of polystyrene, Mn (Indicates a number average molecular weight in terms of polystyrene) of from 0.1 to 50% by weight of a (co) polymer having a value of more than 3.0 and 99.9 to 50% by weight of (B) another thermoplastic polymer [where (A ) +
(B) = 100% by weight] in a latex state and then co-coagulated to provide a thermoplastic resin composition (hereinafter also referred to as “thermoplastic resin composition”). Further, the present invention, the thermoplastic resin composition 0.5 ~
A vinyl chloride-based resin composition (hereinafter referred to as "vinyl chloride") having 60% by weight and 99.5 to 40% by weight of a vinyl chloride-based resin (provided that thermoplastic resin composition + vinyl chloride-based resin = 100% by weight). Also, the present invention provides the above-mentioned thermoplastic resin composition and vinyl chloride-based resin composition.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Thermoplastic resin composition The component (A) used in the thermoplastic resin composition of the present invention is an aromatic vinyl compound, a vinyl cyanide compound and, if necessary, copolymerizable therewith. It is a thermoplastic (co) polymer having a high molecular weight and a wide molecular weight distribution, obtained by (co) polymerizing at least one selected from the group of other vinyl monomers. Here, examples of the aromatic vinyl compound include styrene, α-methylstyrene, p-methylstyrene, monobromostyrene, dibromostyrene,
Tribromostyrene, chlorostyrene and the like,
These can be used alone or in combination of two or more. Preferably, it is styrene.

[0007] Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile.
These can be used alone or as a mixture of two or more. Preferably, it is acrylonitrile.

Further, other copolymerizable vinyl monomers include methyl acrylate, ethyl acrylate,
Acrylates such as propyl acrylate, butyl acrylate, amino acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, dodecyl acrylate, octadecyl acrylate, phenyl acrylate, and benzyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate;
Butyl methacrylate, amino methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, phenyl methacrylate, benzyl methacrylate and other methacrylic acid esters; maleic anhydride, itaconic anhydride, citraconic anhydride and the like Unsaturated acid anhydrides; unsaturated acids such as acrylic acid and methacrylic acid; maleimide, N-methylmaleimide, N-butylmaleimide;
Α, such as N- (p-methylphenyl) maleimide, N-phenylmaleimide and N-cyclohexylmaleimide;
imide compounds of β-unsaturated dicarboxylic acids; epoxy group-containing unsaturated compounds such as glycidyl methacrylate and allyl glycidyl ether; unsaturated carboxylic acid amides such as acrylamide and methacrylamide;
Amino group-containing unsaturated compounds such as aminomethyl methacrylate, aminoether methacrylate, aminopropyl methacrylate and aminostyrene; 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4-hydroxy-2- Butene, trans-4-hydroxy-2-
Butene, 3-hydroxy-2-methyl-1-propene,
Examples include a hydroxyl group-containing unsaturated compound such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and hydroxystyrene; and an oxazoline group-containing unsaturated compound such as vinyl oxazoline. The other copolymerizable vinyl monomers can be used alone or in combination of two or more.

The use ratio of the aromatic vinyl compound and the vinyl cyanide compound in the (A) (co) polymer of the present invention is preferably from aromatic vinyl compound / vinyl cyanide in view of the balance between coloring property and processability. Compound = 95-50 / 5-5
% By weight, more preferably 75 to 65/25 to 35% by weight, particularly preferably 73 to 69/27 to 31% by weight.
It is. The proportion of the other copolymerizable vinyl monomer in the (A) (co) polymer of the present invention is 0 to 30% by weight, preferably 0 to 20% by weight.

The intrinsic viscosity [η] of the (A) (co) polymer of the present invention is 1.5 dl / g or more, preferably 2.0 dl / g.
/ G or more, more preferably 2.5 to 10.0 dl /
g, particularly preferably 2.5 to 5.5 dl / g. When the intrinsic viscosity is less than 1.5 dl / g, (A) of the present invention
This is not preferable because the effect of improving processability using the (co) polymer is lost. If it exceeds 10.0 dl / g, poor dispersion may occur, which is not preferable. Here, the intrinsic viscosity [η] is determined by completely dissolving the (A) (co) polymer of the present invention in dimethylformamide, making five points having different concentrations, and using an Ubbelohde viscosity tube to measure each concentration at 30 ° C. Is a value obtained from the result of measuring the reduced viscosity of

The (A) (co) polymer of the present invention has a molecular weight distribution, that is, a weight average molecular weight / number average molecular weight ratio (Mw / Mn) in terms of polystyrene determined by gel permeation chromatography (GPC) of 3. It is necessary to exceed 0, preferably 4.0 or more, more preferably 5.0 or more, and particularly preferably 5.0 to 15.0.
When it is 3.0 or less, when obtaining the resin composition of the present invention,
(A) Dispersing the (co) polymer takes a long time, which is not preferable. In the case of short-time melt-kneading, the dispersibility of the component (A) is poor, and not only the effect of improving the desired workability is small, but also the mechanical strength of the obtained resin composition is poor, which is not preferable. Here, the molecular weight distribution (Mw / Mn) of the (A) (co) polymer of the present invention was measured by gel permeation chromatography using dimethylformamide as a solvent, and the weight average obtained by calibrating the molecular weight based on polystyrene. It is a value obtained from the molecular weight (Mw) and the number average molecular weight (Mn).

The amount of the (A) (co) polymer used in the thermoplastic resin composition of the present invention is 50 to 50 in terms of solid content.
It is 0.1% by weight, preferably 40 to 0.3% by weight, more preferably 30 to 0.5% by weight. If the content exceeds 50% by weight, the viscosity of the molten resin increases, causing poor appearance. On the other hand, if it is less than 0.1% by weight, the effect of improving the resin cannot be obtained.

The intrinsic viscosity, weight average molecular weight and number average molecular weight of the (A) (co) polymer of the present invention are controlled by changing the type and amount of a polymerization initiator, a chain transfer agent, an emulsifier, a solvent and the like. be able to. Also, a method for adding a monomer component,
It can be controlled by changing the addition time, the polymerization time, the polymerization temperature and the like. Here, as the polymerization method, known polymerization methods such as emulsion polymerization, solution polymerization, suspension polymerization, bulk polymerization, or a polymerization method combining these can be used. In particular, the intrinsic viscosity of the (A) (co) polymer of the present invention can be adjusted by adding a chain transfer agent, but is preferably adjusted by the amount of the polymerization initiator used. In order to obtain the (A) (co) polymer of the present invention, particularly in emulsion polymerization using an emulsifier having a low CMC (critical micelle concentration), a small amount of a water-soluble polymerization initiator is used without using a chain transfer agent, It is preferable to employ a polymerization method in which the monomer components are added in multiple stages and the polymerization temperature is controlled to a relatively low polymerization temperature.

The (A) (co) polymer used in the present invention has a considerably higher molecular weight than a commonly used styrene resin, but a preferred polymerization method for obtaining such a high molecular weight resin. Is an emulsion polymerization. A more preferred polymerization method is a method in which emulsion polymerization is used as the polymerization method, and the monomer components are added all at once or dividedly and polymerized. For the emulsion polymerization, a radical polymerization initiator, an emulsifier, a chain transfer agent and the like are used. Examples of the radical polymerization initiator include an oxidizing agent composed of organic hydroperoxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, t-butylperoxylaurate, and sugar-containing iron pyrophosphate. Redox initiators in combination with reducing agents such as formulations, sulfoxylate formulations, and mixed formulations of sugar-containing iron pyrophosphate formulation / sulfoxylate formulation; persulfates such as potassium persulfate and ammonium persulfate; azobisiso Azo compounds such as butyronitrile, dimethyl-2,2'-azobisisobutyrate, and 2-carbamoylazaisobutyronitrile; organic peroxides such as benzoyl peroxide and lauroyl peroxide; Preferably persulfate Umm is a water-soluble initiator such as. The amount of these radical polymerization initiators used is
Usually, 0.1 part by weight per 100 parts by weight of the monomer component used.
It is about 0.5 to 5 parts by weight, preferably about 0.1 to 3 parts by weight.

Examples of the emulsifier include sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium diphenylether disulfonate, sodium dialkali ester succinate, sodium or potassium salts of aliphatic carboxylic acids having 10 to 20 carbon atoms, and rosin acid. Anionic emulsifiers such as sodium salt or potassium salt, or nonionic emulsifiers such as polyoxyethylene alkyl ester and polyoxyethylene alkyl allyl ether. These may be used alone or in combination of two or more. Can also be used as a mixture. As the emulsifier, a method using a low critical micelle concentration is preferable. Here, the critical micelle concentration is preferably 30 mmol / L or less, more preferably 15 mmol / L or less. The amount of the emulsifier to be used is usually 0.5 to 5 parts by weight based on 100 parts by weight of the monomer component.

Examples of the chain transfer agent include mercaptans such as octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-hexyl mercaptan, n-hexadecyl mercaptan, n-tetradecyl mercaptan, t-tetradecyl mercaptan, and tetraethyl. Thiuram sulfide, carbon tetrachloride, ethylene bromide,
Examples thereof include hydrocarbon salts such as pentanephenylethane, terpenes, acrolein, methacrolein, allyl alcohol, 2-ethylhexylthioglycol, and α-methylstyrene dimer. These chain transfer agents can be used alone or in combination of two or more. The amount of the chain transfer agent to be used is generally 0 to 1 part by weight based on 100 parts by weight of the monomer component.

(A) In the polymerization of the (co) polymer, in addition to a radical polymerization initiator, an emulsifier, a chain transfer agent, and the like,
If necessary, use various electrolytes, pH adjusters, etc.
Usually, water is added in an amount of 100 to 100 parts by weight of the monomer component.
500 parts by weight and the above radical polymerization initiator, emulsifier, chain transfer agent and the like are used in an amount within the above range, and the polymerization temperature is usually 40 to 100 ° C, preferably 50 to 90 ° C, and the polymerization time is 1
Emulsion polymerization is carried out for 10 hours to 10 hours.

Next, as the other thermoplastic polymer (B) used in the thermoplastic resin composition of the present invention, acrylic rubber, silicone rubber, fluorine rubber, butyl rubber, butadiene rubber, ethylene-α-olefin rubber Rubber, NB
R, SBR, SIS, SEPS, SEBS, rubbery polymers such as thermoplastic polyurethanes; at least one selected from the group consisting of the above-mentioned aromatic vinyl compounds, vinyl cyanide compounds and other copolymerizable vinyl monomers. A (co) polymer comprising a seed having an intrinsic viscosity of 0.2 to 1.0 dl
/ G of (co) polymer, preferably styrene-acrylonitrile copolymer, polymethyl methacrylate, styrene-
Examples include a methyl methacrylate copolymer and a styrene-N-phenylmaleimide copolymer.

Further, (B) the other thermoplastic polymer includes, in the presence of the above rubbery polymer, the above aromatic vinyl compound, vinyl cyanide compound and other copolymerizable vinyl monomer. Rubber-reinforced thermoplastic resin obtained by graft-polymerizing at least one monomer selected from the group, preferably ABS resin, MBS resin, acrylic rubber-based graft copolymer, silicone rubber-based graft copolymer, AES resin, water And a grafted rubber-based graft copolymer. The above (B) other thermoplastic polymers can be used alone or in combination of two or more.

The amount of the other thermoplastic polymer (B) used in the thermoplastic resin composition of the present invention is from 50 to 99.9.
% By weight, preferably 60 to 99.7% by weight, and more preferably 70 to 99.5% by weight, and if it is less than 50% by weight, the viscosity of the molten resin becomes high, causing poor appearance. On the other hand, if it exceeds 99.9% by weight, the effect of adding the (A) (co) polymer cannot be obtained.

The thermoplastic resin composition of the present invention is obtained by mixing the above (A) (co) polymer latex and (B) a latex of another thermoplastic resin obtained by emulsion polymerization. After a collection process such as coagulation and washing,
After drying, a powder is obtained. As the coagulant used in the coagulation step, sulfuric acid, magnesium sulfate, calcium chloride, aluminum sulfate or the like is used as an aqueous solution. Further, the mixed latex can be spray-dried with a spray dryer. The thermoplastic resin composition of the present invention comprises the above (A) (co) polymer and (B) another thermoplastic polymer,
By mixing in the latex state and then co-coagulating, the dispersion state of the component (A) with respect to the component (B) becomes better as compared with the case of blending those coagulated individually. Therefore, the entanglement effect of the component (A) is enhanced, and an effect is obtained in which drawdown properties when heated and melted and flow marks during molding are improved.

Vinyl Chloride Resin Composition By blending the above thermoplastic resin composition with a vinyl chloride resin, a vinyl chloride resin composition having improved heat melt processability of the vinyl chloride resin can be obtained. . The vinyl chloride resin used in the present invention is a vinyl chloride homopolymer or a copolymer of not less than 80% by weight of vinyl chloride and not more than 20% by weight of another monomer copolymerizable therewith. is there. Here, other copolymerizable monomers include ethylene, propylene, vinyl bromide, vinylidene chloride, vinyl acetate, acrylic esters, methacrylic esters, and the like. The average degree of polymerization of the vinyl chloride resin used in the present invention is usually 700 to
It is 1,400, preferably 700-1,200.

The mixing ratio of the thermoplastic resin composition and the vinyl chloride resin in the vinyl chloride resin composition of the present invention is such that the thermoplastic resin composition is 0.5 to 60% by weight, preferably 3 to 40% by weight. The amount of the vinyl chloride resin is 99.5% by weight to 40% by weight, preferably 97 to 60% by weight.
When the amount of the thermoplastic resin composition used is less than 0.5% by weight (the vinyl chloride-based resin exceeds 99.5% by weight), the effect of improving the processability of the vinyl chloride-based resin is small. If the amount is too large (the vinyl chloride-based resin is less than 40% by weight), the processability is good, but it is not economical and thus not preferable.

The mixing of the thermoplastic resin composition of the present invention with a vinyl chloride resin is generally carried out by a known kneading machine, for example, a known extruder, a Banbury mixer, a kneader, a calender roll, a ribbon blender, a Henschel mixer or the like. Using a mixer, kneader, preferably 120 to
It is obtained by kneading at a melting temperature of 220 ° C.

In the resin composition of the present invention, if necessary,
Dyes, pigments, heat stabilizers, antioxidants, weathering (light) agents, organic and inorganic reinforcing materials, flame retardants, antibacterial and antifungal agents, processing aids such as ultra-high molecular weight PTFE, foaming agents, plasticizers, lubricants And the like.

The resin composition of the present invention thus obtained can be used for sheet / film extrusion molding, foam extrusion molding, profile extrusion molding, blow molding, inflation molding, injection molding, vacuum molding, compression molding, rotational molding and the like. A product can be obtained by a molding method. Products obtained by the molding method can be widely used as parts in various fields such as a building material field, a vehicle field, an OA / home electric appliance field, a sanitary field, and miscellaneous goods.

[0027]

EXAMPLES The present invention will now be described more specifically with reference to examples. Parts and% in Examples are parts by weight and% by weight unless otherwise specified. During the implementation, various measurement items were as described below.

The limiting viscosity copolymer is completely dissolved in dimethylformamide,
Five points with different concentrations were made, and using an Ubbelohde viscosity tube,
From the result of measuring the reduced viscosity at each concentration of 0 ° C., the intrinsic viscosity [η] was determined. Graft rate The graft rate (Gf) was calculated from the acetone-insoluble component [gel component (g)] and the rubber content (b) by the following formula. Gf = [(g−b) / b] × 100 (%)

Weight average molecular weight (Mw), number average molecular weight
(Mn) and molecular weight distribution (Mw / Mn) manufactured by Waters Co., Ltd., gel permeation chromatography (GPC-244), Tosoh Corporation as a column
TSK-gel-GMH x 1 (2), dimethylformamide as solvent, flow rate 0.8 ml / min, temperature 23 ° C
And calibrated against polystyrene standards.

The mixture was kneaded at 180 ° C. with a draw-down twin screw extruder to obtain pellets. The pellets were heated at 170 ° C. by the following method.
, The drawdown time (second) was measured. That is,
2 g of the obtained pellet was weighed, packed in an elevated flow tester cylinder, heated for 10 minutes, then subjected to a load of 50 kg, extruded 0.5 cc, and removed the load.
The start time was set. While measuring the diameter of the resin rod extruded from the bottom of the flow test, keep the temperature constant,
The time (sec) required to reach 80% of the diameter of the resin rod at the start time was measured.

Blow molding characteristics A blow molded product having an average thickness of 1.5 mm was obtained using the resin composition. The upper part of the mold was cut off, and the minimum thickness (mm) was measured. Using a resin composition having injection molding characteristics , a flat plate having a direct gate at the center of the molded product was injection molded. The state of the flow mark on the surface of the molded product was evaluated according to the following evaluation criteria. ；: No flow mark, good appearance ×: flow mark, poor appearance

Preparation of Component (A) Potassium stearate is used as an emulsifier, potassium persulfate is used as a polymerization initiator, styrene and acrylonitrile are used as monomer components, and if necessary, methyl methacrylate or n-butyl acrylate is used. According to the emulsion polymerization method, copolymers A-1 to 1 having a composition shown in Table 1, an intrinsic viscosity [η], and a weight average molecular weight / number average molecular weight ratio (Mw / Mn).
8 was obtained. [Η] and Mw / Mn were obtained as desired by changing the amounts of the emulsifier and the polymerization initiator and the method of adding the monomer.

[0033]

[Table 1]

Preparation of Component (B) Conjugated diene-based rubbery polymer; the conjugated diene-based rubbery polymer shown in Table 2 was used as the base rubber of the rubber-reinforced thermoplastic resin as the component (B). Was.

[0035]

[Table 2]

(Rubber reinforced) thermoplastic resin; reflux condenser,
In a reaction vessel equipped with a thermometer and a stirrer, in the presence or absence of the conjugated diene-based rubbery polymer (solid content conversion) of Table 2 previously produced by emulsion polymerization, 3 parts of potassium rosinate and Table 3 A monomer component was charged, and 0.25 part of sodium pyrophosphate, 0.35 part of glucose, 0.005 part of ferrous sulfate and 0.6 part of cumene hydroperoxide were added to initiate polymerization, and the reaction was carried out for 6 hours. Was done.
The obtained copolymer latex is coagulated by adding sulfuric acid,
The resin was washed with water and dried to obtain a (rubber-reinforced) thermoplastic resin shown in Table 3.

[0037]

[Table 3]

*) In the monomer components, ST is styrene, AN
Is acrylonitrile, MMA is methyl methacrylate,
MA is methacrylic acid. Preparation of Vinyl Chloride Resin Polyvinyl chloride (PVC) having a polymerization degree of 700 was used.

Examples 1 to 9 and Comparative Examples 1 to 5 The above components were mixed at the mixing ratios shown in Tables 4 and 5 using a Henschel mixer, kneaded with a Banbury mixer, and pelletized. Was.

[0040]

[Table 4]

[0041]

[Table 5]

As is clear from Table 4, the compositions of the present invention (Examples 1 to 9) are excellent in drawdown resistance, blow moldability, and molded appearance. On the other hand, in Comparative Examples 1 and 2 in Table 5, the intrinsic viscosity or Mw / Mn of the component (A) is out of the range of the present invention, and the drawdown time is reduced. The appearance of Comparative Example 3 is deteriorated because the use ratio of (A) / (B) is out of the range of the present invention. Comparative Examples 4 and 5
Has a low appearance due to the small amount of the vinyl chloride resin used.

[0043]

The thermoplastic resin composition of the present invention and the vinyl chloride-based resin composition using the same have excellent heat-melt moldability.

Claims (2)

[Claims] (A) at least one member selected from the group consisting of (A) an aromatic vinyl compound, a vinyl cyanide compound, and, if necessary, another vinyl monomer copolymerizable therewith; It is obtained by polymerization and has an intrinsic viscosity of 1.5 dl / g or more and gel permeation chromatography (GP
C) Mw / Mn (where Mw represents a weight average molecular weight in terms of polystyrene and Mn represents a number average molecular weight in terms of polystyrene) of more than 3.0 (co) polymer 0.1 to
50% by weight and (B) 99.9-50 other thermoplastic polymers
A thermoplastic resin composition obtained by mixing in a latex state with (A) + (B) = 100% by weight, followed by co-coagulation. 2. The thermoplastic resin composition according to claim 1,
5 to 60% by weight, and 99.5 to 4% of vinyl chloride resin
A vinyl chloride resin composition containing 0% by weight (however, thermoplastic resin composition + vinyl chloride resin = 100% by weight) as a main component.