JP2000309716A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition reduced in a load on the screw of an extruder during being plasticized and improved in extrudability by compounding a rubber-modified thermoplastic resin with a paraffin wax. SOLUTION: A rubber-modified thermoplastic resin (100 pts.wt.) containing 5-60 wt.% at least one rubbery polymer selected from among a butadiene rubber, a crosslinked acrylic rubber, and a polyorganosiloxane rubber and comprising 10-50 wt.% vinyl cyanide monomer units, 50-90 wt.% aromatic vinyl monomer units, and, optionally, at most 10 wt.% (meth)acrylic ester monomer units is compounded with 0.1-20 pts.wt. paraffin wax having a number-average molecular weight of 400-2,000, desirably, 800-1,500, and, optionally, additives such as a stabilizer of a hindered phenol, phosphite, or like type, a colorant, a metallic soap, a plasticizer, a reinforcernent, a flame retardant, an antibacterial agent, and an anti-mold agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition used for extrusion molding.

[0002]

2. Description of the Related Art In extrusion molding, vinyl chloride resin is often used because of its good formability. In recent years, the use of vinyl chloride resin has tended to be avoided due to environmental issues such as the generation of dioxin during combustion, and relatively inexpensive materials have been desired instead, and rubber-modified thermoplastic resins such as ABS resins have been used. It is getting.

However, when a rubber-modified thermoplastic resin such as an ABS resin is subjected to extrusion molding, a load applied to a screw of an extruder at the time of plasticization in a cylinder is larger than that of a vinyl chloride resin. Is not raised, that is, productivity is poor.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic resin having good extrusion productivity by reducing the load applied to the screw of an extruder during plasticization.

[0005]

The gist of the present invention is that a paraffin wax (B) having a number average molecular weight of 400 to 2,000 is contained in an amount of 0.1 to 20 per 100 parts by weight of a rubber-modified thermoplastic resin (A). It is in the thermoplastic resin composition blended by weight.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The rubber-modified thermoplastic resin (A) used in the present invention refers to a vinyl cyanide monomer (A-2-1) in the presence of a rubbery polymer (A-1). , An aromatic vinyl monomer (A-2-2) and a monomer (mixture) of at least one selected from (meth) acrylate monomers (A-2-3) (A-2 ) Is obtained by graft polymerization.

As the rubbery polymer (A-1), at least one selected from the group consisting of butadiene rubber, crosslinked acrylic rubber, and polyorganosiloxane rubber is used. Composite rubbers such as polybutadiene / polybutyl acrylate in which polybutadiene is provided on the outer layer of polybutadiene as these rubbery polymers (A-1);
A composite rubber of a polysiloxane rubber and a polyacrylic acid rubber, a composite rubber of the above rubbery polymer components composed of other combinations, or a mixture of two or more thereof can also be used.

Composite rubbers such as crosslinked acrylic rubber, polyorganosiloxane rubber, polybutadiene / polybutyl acrylate in which polybutyl acrylate is provided on the outer layer of polybutadiene, and composite rubber of polysiloxane rubber and polyacrylic rubber are: It is excellent in weather resistance and chemical resistance, and is particularly preferably used outdoors and on windows.

Examples of the vinyl cyanide monomer (A-2-1) include acrylonitrile, methacrylonitrile, ethacrylonitrile fumaronitrile and the like, and these can be used alone or in combination.

Also, an aromatic vinyl monomer (A-2-2)
Styrene, α-methylstyrene, o-methylstyrene, 1,3-dimethylstyrene, p-methylstyrene, t-butylstyrene, halogenated styrene, p-
Ethyl styrene and the like are used, and these can be used alone or in combination.

The (meth) acrylate monomer (A-
Examples of 2-3) include methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, and the like. These can be used alone or in combination.

Also, other vinyl monomers (A-2-4) of (A-2-1) to (A-2-3) can be used. Examples of other vinyl monomers include a maleimide monomer such as N-phenylmaleimide, and a pyridine monomer, but are not particularly limited thereto.

In order to graft-polymerize such a monomer (mixture) (A-2) to the rubbery polymer (A-1), a known graft polymerization method such as emulsion polymerization is used.

The rubber-modified thermoplastic resin (A) preferably contains the rubbery polymer (A-1) in the range of 10 to 90% by weight.

The rubber-modified thermoplastic resin (A) has a copolymer comprising a vinyl cyanide monomer unit (A-2-1) and an aromatic vinyl monomer unit (A-2-2). (A-3), methyl methacrylate-based copolymer (A-
At least one selected from 4) can be arbitrarily added. The addition amount of the copolymers (A-3, A-4) is adjusted so that the content of the rubbery polymer (A-1) contained in the rubber-modified thermoplastic resin (A) is 5 to 60% by weight. Preferably. If it is less than 5% by weight, the impact strength is insufficient, and
Exceeding 0% by weight makes extrusion difficult.

The vinyl cyanide monomer unit (A-2-
As 1), an acrylonitrile unit and an aromatic vinyl monomer unit (A-2-2) are styrene units,
Particularly preferred.

A vinyl cyanide monomer unit (A-2-
1) and a vinyl cyanide monomer unit (A-2-1) and an aromatic vinyl monomer in a copolymer (A-3) comprising the aromatic vinyl monomer unit (A-2-2) The content of the monomer unit (A-2-2) is 10 to 50% by weight, respectively.
And a range of 50 to 90% by weight.

The amount of the (meth) acrylic ester monomer (A-2-3) and / or other vinyls of (A-2-1) to (A-2-3) is less than 10% by weight. The monomer (A-2-4) can be contained in the copolymer (A-3). (Meth) acrylic acid ester monomer (A-
2-3) and other vinyl monomers (A-2-4) are units derived from the same monomers as the above-mentioned monomer (mixture) (A-2).

A vinyl cyanide monomer unit (A-2-
Known methods such as solution polymerization, suspension polymerization and bulk polymerization are used for the production of the copolymer (A-3) composed of 1) and the aromatic vinyl monomer unit (A-2-2).

The methyl methacrylate copolymer (A-
4) can contain vinyl units other than methyl methacrylate. Examples of the vinyl monomer include an alkyl (meth) acrylate other than methyl methacrylate and styrene.

Methyl methacrylate copolymer (A-
For the production of 4), known methods such as solution polymerization, suspension polymerization and bulk polymerization are used.

The paraffin wax (B) used in the present invention is crystalline paraffin separated and refined from petroleum. A compound represented by the general chemical formula CnH2n + 2 and having a number average molecular weight of 400 to 2,000 is preferable.

The number average molecular weight was calculated by investigating the increase in boiling point in a toluene solution. (Ebullioscopic Method) When the number average molecular weight is less than 400, a large amount of gas is generated at the time of extrusion molding, and a die line is generated in eyes and a good molded appearance cannot be obtained. In addition, the number average molecular weight is 20
If it exceeds 00, the effect of reducing the load during extrusion molding is small.
Further, the number average molecular weight is preferably from 800 to 1500.

The paraffin wax (B) is used in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the rubber-modified thermoplastic resin (A). When the amount of the paraffin wax is 0.
When the amount is less than 1 part by weight, the load reducing effect at the time of extrusion molding is small. When the amount exceeds 20 parts by weight, the load reducing effect at the time of extrusion molding is obtained, but the penetration into the cylinder is poor and the discharge amount is low, and the productivity is low. Gets worse.

As a method for preparing the rubber-modified thermoplastic resin (A) and the paraffin wax (B), a high-speed mixer such as a Henschel mixer used for blending ordinary resins,
Mixing devices such as tumblers and pelletizers can be used. For further melt kneading, a single screw extruder, 2
A known device such as a shaft extruder can be used, and there is no particular limitation.

When the rubber-modified thermoplastic resin (A) and the paraffin wax (B) are blended, various stabilizers can be blended if necessary.

As the stabilizer, there may be mentioned antioxidants such as findered phenol, phosphite and thioether, benzotriazole and benzophenone ultraviolet absorbers and hindered amine light stabilizers.

Further, in addition to the stabilizer, various coloring agents, metal soaps, plasticizers and the like can be blended. Examples of the metal soap that can be blended include salts of stearic acid such as magnesium, calcium, barium, and zinc.

Further, a copolymer containing methyl methacrylate unit and alkyl acrylate unit as essential components can be added to the resin composition according to the purpose. By blending them, the molding processability at the time of extrusion molding is improved, and further, the appearance of the obtained molded product is improved.

Here, the methyl methacrylate unit and the alkyl acrylate unit are derived from a methacrylate ester and an alkyl acrylate ester, respectively. To 18 alkyl groups, such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, benzyl acrylate, phenyl acrylate, etc. Is mentioned.

The copolymer containing methyl methacrylate unit and alkyl acrylate unit as essential components is not particularly limited. However, in order to improve the appearance, a copolymer such as Metablen L-1000 manufactured by Mitsubishi Rayon Co., Ltd. may be used. For example, if the purpose is to achieve uniform cells during drawdown and foam extrusion, Mitsubishi Rayon Co., Ltd.
Examples thereof include Metablen P531A and P551.

Further, a reinforcing material, a twist-resistant agent and an antibacterial / spinning agent can be added.

The reinforcing material to be mixed here is at least one selected from inorganic fibers such as glass fibers and carbon fibers, and inorganic fillers such as wollastonite, talc, mica powder, glass foil and potassium titanate. The amount of the reinforcing material is from 0 to 60 with respect to (A) + (B) = 100 parts by weight.
Parts by weight, preferably 1 to 50 parts by weight.

[0034] As the flame retardant, inorganic flame retardants such as halogen compounds and antimony compounds, which are usually used for flame retardation of ABS resins and thermoplastic polyester resins, and phosphorus flame retardants such as phosphorus flame retardants are used. Examples of the halogen compound include halogenated diphenyl ethers such as degabromodiphenyl ether and octabromodiphenyl ether, and halogenated compounds such as halogenated polycarbonate.

Examples of the inorganic flame retardant include antimony trioxide, antimony tetroxide, antimony pentoxide, sodium pyroantimonate, aluminum hydroxide, and the like. Absent.
The compounding amount of the halogen compound is 0 to 35 parts by weight, preferably 1 to 30 parts by weight based on 100 parts by weight of (A) + (B), and that of the antimony compound is 0 to 25 parts by weight, preferably 1 to 25 parts by weight. It is in the range of 20 parts by weight.

Further, a compound such as tetrafluoroethylene can be added as a flame retardant aid to prevent drip.

Examples of the antibacterial and antifungal agents include organic agents such as imidazole, thiazole, nitrile, haloalkyl and pyridine, and inorganic agents such as silver, zinc, copper and titanium. Is mentioned. Of these, it is preferable to use a silver-based material that is thermally stable and has high performance. Silver-based antibacterial agents include zeolite, silica gel,
There are porous structures such as zirconium phosphate, calcium phosphate, hydrotalcite, hydroxyapatite, calcium silicate, etc. in which silver, silver ions, silver complexes, silver compounds are supported, and other silver salts of fatty acids. And silver salts of phosphoric acid alkyl esters.

[0038]

EXAMPLES Examples will be specifically described below. The present invention is not limited to these examples. Further, “parts” and “%” in the examples mean “parts by weight” and “% by weight”, respectively.

(Production of rubbery polymer A-1-) 96 parts of octamethyltetracyclosiloxane, 2 parts of γ-methacryloxypropyldimethoxymethylsilane and 2 parts of ethyl orthosilicate were mixed to obtain 100 parts of a siloxane-based mixture. Was. To this, 300 parts of distilled water in which 0.67 part of sodium dodecylbenzenesulfonate was dissolved was added, and the mixture was stirred with a homomixer at 10,000 rpm for 2 minutes, and then passed through a homogenizer once at a pressure of 300 kg / cm ² . A stable premixed organosiloxane latex was obtained.

On the other hand, 2 parts of dodecylbenzenesulfonic acid and 98 parts of distilled water were injected into a reactor equipped with a reagent injection container, a cooling pipe, a jacket heater and a stirrer.
Of dodecylbenzenesulfonic acid was prepared.

While this aqueous solution was heated to 85 ° C., the premixed organosiloxane latex was added dropwise over 4 hours, and after completion of the addition, the temperature was maintained for 1 hour and the system was cooled. The reaction solution was left at room temperature for 48 hours, and then neutralized with an aqueous solution of sodium hydroxide.

The latex thus obtained (L-
1) was dried at 170 ° C. for 30 minutes to obtain a solid content, which was 17.3%. The weight average particle diameter of the polyorganosiloxane in the latex was 0.08 μm. The gel content of the polyorganosiloxane is 85%,
The degree of swelling measured in a toluene solvent was 14.5.

119.5 parts of polyorganosiloxane latex (L-1) and sodium polyoxyethylene alkylphenyl ether sulfate (Kao Co., Ltd.) were placed in a reactor equipped with a reagent injection vessel, a cooling pipe, a jacket heater and a stirrer. 0.8) Emar NC-35)
After adding and mixing 203 parts of distilled water, 53.2 parts of n-butyl acrylate, 0.21 part of allyl methacrylate,
0.11 part of 3-butylene glycol dimethacrylate and tert-butyl hydroperoxide 0.1
A mixture of 3 parts was added.

The atmosphere was replaced with nitrogen by passing a nitrogen stream through the reactor, and the temperature was raised to 60 ° C. When the internal liquid temperature reaches 60 ° C., ferrous sulfate 0.00
01 parts, ethylenediaminetetraacetic acid disodium salt 0.0
An aqueous solution in which 003 parts and 0.24 parts of Rongalid were dissolved in 10 parts of distilled water was added to initiate radical polymerization. The liquid temperature rose to 78 ° C. due to the polymerization of the acrylate component. This state was maintained for 1 hour to complete the polymerization of the acrylate component, thereby obtaining a composite rubber latex of polyorganosiloxane and butyl acrylate rubber.

After the liquid temperature inside the reactor dropped to 60 ° C.,
An aqueous solution obtained by dissolving 0.4 part of Rongalid in 10 parts of distilled water is added, and then a mixed solution of 11.1 parts of acrylonitrile, 33.2 parts of styrene and 0.2 part of tertiary butyl hydroperoxide is added for about 1 hour. The mixture was dropped and polymerized. After holding for 1 hour after the completion of the dropwise addition, ferrous sulfate was added to a solution containing 0.1 mg of ferrous sulfate.
0002 parts, 0.0006 part of ethylenediaminetetraacetic acid disodium salt and 0.25 part of Rongalide in 10 parts of distilled water were added, and then 7.4 parts of acrylonitrile, 22.2 parts of styrene and tert-butylhydrogen were added. A mixture of 0.1 part of peroxide was added dropwise over about 40 minutes to carry out polymerization. After holding for 1 hour after the completion of the dropping, the mixture was cooled and a latex of a graft copolymer obtained by grafting an acrylonitrile-styrene copolymer on a composite rubber comprising a polyorganosiloxane and a butyl acrylate rubber was obtained. The weight average particle size of the graft copolymer in the latex determined by the dynamic light scattering method was 0.13 μm.
m.

Next, 150 parts of an aqueous solution containing 5% calcium acetate dissolved therein was heated to 60 ° C. and stirred. 100 parts of the latex of the graft copolymer was gradually dropped into this, and solidified. Next, the precipitate was separated, washed, and dried to obtain a rubbery polymer A-1-.

(Production of Rubbery Polymer A-1-) 20 parts (as solid content) of polybutadiene latex having a solid content of 35% and an average particle size of 0.08 μm were mixed with n-acrylic acid.
0.4 parts (as a solid content) of a copolymer latex having an average particle diameter of 0.08 μm composed of 85% of butyl units and 15% of methacrylic acid units are added with stirring, and stirring is continued for 30 minutes to obtain an average particle diameter of 0.28 μm. Was obtained. Transfer 20 parts (solid content) of the resulting enlarged diene rubber latex to a reaction vessel, add 1 part of disproportionated potassium rosinate and 150 parts of ion-exchanged water, perform nitrogen replacement, and bring the temperature to 70 ° C. (internal temperature). The temperature rose. A solution prepared by dissolving 0.12 parts of potassium persulfate in 10 parts of ion-exchanged water was added thereto, and the following nitrogen-substituted monomer mixture was continuously dropped over 2 hours.

N-Butyl acrylate 80 parts Allyl methacrylate 0.32 parts Ethylene glycol dimethacrylate 0.16 parts At the end of the dropping, the internal temperature does not rise, but is further increased by 80.
C. and the reaction was continued for 1 hour.
%, Thereby obtaining a multi-layer acrylic rubber containing an enlarged diene rubber inside. The swelling degree of this multi-layer acrylic rubber (ratio of swelling weight after immersion in methyl ethyl ketone for 24 hours at 30 ° C. to standing dry weight) is 6.4, gel content is 93.0%, and particle diameter is 0. It was 28 μm.

50 parts (solid content) of a multi-layer acrylic rubber latex was placed in a reaction vessel, and 140 parts of ion-exchanged water was added for dilution, and the temperature was raised to 70 ° C. Acrylonitrile /
50 parts of a graft polymer mixture composed of styrene = 29/71 (weight ratio) was adjusted, and 0.35 parts of benzoyl peroxide was dissolved, followed by purging with nitrogen. This monomer mixture was added to the above reaction system at a rate of 15 parts / hour using a metering pump. After the completion of the injection of all the monomers, the temperature in the system was raised to 80 ° C., and stirring was continued for 30 minutes to obtain a graft polymer latex. The conversion was 99%.

Dilute sulfuric acid was added to a part of the latex, and the solidified and dried powder was extracted under reflux of methyl ethyl ketone.
The ηsp / C of the extracted portion was measured at 25 ° C. using dimethylformamide as a solvent and found to be 0.67.

The latex produced as described above is
Aluminum chloride (A1Cl3) three times the total latex
. (6H2 O) into a 0.15% aqueous solution (90 DEG C.) with stirring to coagulate. After the addition of all the latex was completed, the temperature in the coagulation bath was raised to 93 ° C., and left as it was for 5 minutes. After cooling, it was drained and washed by a centrifugal dehydrator and dried to obtain a dry powder of a rubbery polymer A-1-.

(Production of rubbery polymer A-1-) 50 parts (as solid content) of polybutadiene latex having a solid content of 35% and an average particle size of 0.08 μm were added with n-acrylic acid.
One part (as solid content) of a copolymer latex having an average particle diameter of 0.08 μm consisting of 85% of butyl units and 15% of methacrylic acid units is added with stirring, and stirring is continued for 30 minutes to enlarge the average particle diameter of 0.28 μm. A rubber latex was obtained.

The obtained enlarged rubber latex was added to the reaction vessel, and 50 parts of distilled water and wood rosin emulsifier 2 were added.
Parts, Demol N (trade name, manufactured by Kao Corporation, 0.2 part of naphthalenesulfonic acid formalin condensate), 0.02 part of sodium hydroxide, and 0.35 part of dextrose were added, and the mixture was heated while stirring. After the addition of 0.05 parts of ferrous sulfate, 0.2 parts of sodium pyrophosphate and 0.03 parts of sodium dithionite at an internal temperature of 60 ° C., 15 parts of acrylonitrile, 35 parts of styrene, A mixture of 0.2 part of peroxide and 0.5 part of tert-dodecyl mercaptan was continuously added dropwise over 90 minutes, and then cooled for 1 hour. The resulting graft polymer latex was coagulated with dilute sulfuric acid, washed, filtered, and dried to obtain a rubbery polymer A-1-.

(Production of copolymer (A-3-)) A copolymer having a composition of acrylonitrile unit 29% and styrene unit 71% was obtained by a suspension polymerization method. 25 of this copolymer
The reduced viscosity at ℃ (ηsp / C) was 0.62 (measured value in a 0.2% dimethylformamide solution).

(Acrypet VH manufactured by Mitsubishi Rayon Co., Ltd.) was used as the copolymer (A-4-) polymethyl methacrylate resin.

(Paraffin wax (B)) A commercially available paraffin wax was used. These number average molecular weights are 300 (B-1), 600 (B-2),
1000 (B-3), 1700 (B-5), 2200
(B-5).

(Others) Mitsubishi Rayon Co., Ltd., which is a commercially available copolymer containing methyl methacrylate units and alkyl acrylate units as essential components
Metablen L-1000 (C-1), Metablen P-
530A (C-2) was used.

As a reinforcing material, talc (C-3), which is generally commercially available and has an average particle size of 2.8 μm, was used.

As the foaming agent, azodicarbonamide (C-4) which is generally commercially available was used.

Compounded according to the composition shown in Tables 1, 2, 3, and 4, mixed with a Henschel mixer for 5 minutes, and pelletized with a 40 mm single screw extruder (with vent) to obtain a thermoplastic resin composition (A + B). Was.

(Load, Sheet Appearance) The pelletized thermoplastic resin composition has a cylinder temperature and a die temperature of 180 ° C.
The sheet was produced using a 40 mm single screw extruder set in the above, and the load applied to the screw of the extruder at that time was determined by the current value. Further, the appearance of the prepared sheet was visually observed.

[0062]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[0063]

According to the present invention, it is possible to provide a thermoplastic resin excellent in extrusion productivity by blending paraffin wax with a rubber-modified thermoplastic resin. .

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B29K 55:02 91:00 F term (Reference) 4F071 AA11X AA22X AA33X AA34X AA67X AA71 AA77 AH19 BA01 BB06 BC01 4F207 AA13 AA45 AA49 AB11 AR15 KA01 KA17 KF01 KF02 KF12 KK12 4J002 AA011 AE052 BN121 BN141 BN171 FD022 GT00

Claims (1)

[Claims] A thermoplastic resin for extrusion molding comprising 0.1 to 20 parts by weight of a paraffin wax (B) having a number average molecular weight of 400 to 2,000 per 100 parts by weight of a rubber-modified thermoplastic resin (A). Resin composition.