JPH0598072A - Thermoplastic resin composition for cleaning - Google Patents

Abstract

PURPOSE:To provide the title composition having remarkable capability of cleaning the inside of a molding machine which is difficult to clean since resin used for molding tends to firmly adhere thereto through, e.g., thermal decomposition. CONSTITUTION:(1) The title composition made by mixing a thermoplastic resin with the normal salt of an alkylbenzenesulfonic acid and basic magnesium stearate. (2) The title composition made by mixing 45-95wt.% thermoplastic resin, 2-40wt.% normal salt of an alkylbenzenesulfonic acid, and 1-10wt.% basic magnesium stearate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning thermoplastic resin composition used for cleaning the interior of a thermoplastic resin molding machine. More specifically, it relates to a thermoplastic resin composition for cleaning in which a neutral salt of alkylbenzene sulfonic acid and basic magnesium stearate are mixed with a thermoplastic resin.

[0002]

2. Description of the Related Art Conventionally, in plastic molding, various means have been adopted in order to eliminate the influence of the preceding type when changing the type of resin used. Especially when molding colored resins, when switching from dark-colored products such as blue and black to light-colored products such as white, disassembling and cleaning the molding machine or co-washing the molding machine with cleaning resin. They had to perform complicated work and cleaning work that required a long production stop. As a method for solving these problems, various cleaning resin resin compositions for cleaning the inside of a molding machine have been developed.

For example, in JP-A-62-195045, 2-30% by weight of alkylbenzene sulfonic acid sodium salt is added to a thermoplastic resin, and a water repellent compound (higher fatty acid metal salt, wax, liquid paraffin, synthetic wax, etc.) is used.
A composition containing 5 to 10% by weight is disclosed in JP-A-63-66.
No. 245, a thermoplastic resin having a neutral salt of sulfonic acid of 2 to 30% by weight and an average particle size of 0.005 to 10 [mu] m in the form of a powdered inorganic compound (silicon dioxide, diatomaceous earth, etc.), 0.05 to
A composition containing 5% by weight is disclosed in JP-A-2-206636.
Japanese Patent Application Laid-Open No. 58-58158 discloses a composition in which 50 to 95% by weight of polystyrene is added to 2 to 40% by weight of a neutral salt of alkylbenzenesulfonic acid and 1.5 to 15% by weight of a releasing compound.
No. 149998 discloses 1 to 15 parts by weight of a nonionic surfactant having a decomposition starting temperature of 200 ° C. or higher, 5 to 30 parts by weight of metal soap, 20 to 70 parts by weight of an inorganic filler, and 20 to 70 of an olefin resin. In JP-A-59-124999, a cleaning resin composition consisting of parts by weight comprises a thermoplastic resin, an inorganic filler and a lubricant, wherein the inorganic filler is about 30 to 70% by weight and the lubricant is about 1 to 30% by weight
A cleaning composition for a molding machine, characterized in that

[0004]

DISCLOSURE OF THE INVENTION The present inventors have earnestly studied to develop an in-machine cleaning resin composition having a higher cleaning ability than the above-mentioned known cleaning resin compositions. as a result,
It was found that by adding a neutral salt of alkylbenzene sulfonic acid and basic magnesium stearate to a thermoplastic resin, a cleaning resin composition having excellent cleaning ability can be obtained, and the present invention was completed based on this finding. As is clear from the above description, an object of the present invention is to provide a cleaning thermoplastic resin composition having excellent cleaning ability as compared with conventional cleaning resin compositions.

[0005]

The present invention has the following configuration. (1) A thermoplastic resin composition for cleaning in which a neutral salt of alkylbenzene sulfonic acid and basic magnesium stearate are mixed with a thermoplastic resin. (2) A thermoplastic resin composition for cleaning containing 45 to 95% by weight of a thermoplastic resin, 2 to 40% by weight of a neutral salt of alkylbenzenesulfonic acid, and 1 to 10% by weight of basic magnesium stearate. (3) The thermoplastic resin is polypropylene, polyethylene,
The thermoplastic resin composition for cleaning according to any one of the above items 1 and 2, which is polybutene, poly-4-methylpentene or polystyrene.

The thermoplastic resin used in the present invention includes polyolefins such as polyethylene, polypropylene, polybutene, poly-4-methylpentene, ethylene-vinyl acetate copolymer, polystyrene, polyacrylonitrile,
Polymethylmethacrylate, MBS resin, AS resin, AAS resin, ABS resin, polyamide resin, polyester resin, polycarbonate resin and the like can be used alone or in combination of two or more.

Examples of the neutral salt of alkylbenzenesulfonic acid used in the present invention include sodium salt, potassium salt, magnesium salt and calcium salt of alkylbenzenesulfonic acid having an alkyl group having 6 to 20 carbon atoms. The content ratio of the neutral salt of alkylbenzenesulfonic acid is preferably 2 to 40% by weight based on the composition. If the use ratio is less than 2% by weight, the cleaning ability of the preceding resin remaining in the machine is small, and if it exceeds 40% by weight, the slipperiness becomes too strong and the cleaning ability may be lowered.

The amount of the basic magnesium stearate used in the present invention is preferably 1 to 10% by weight based on the composition. If the usage ratio is less than 1% by weight, the cleaning ability will be insufficient, and if it exceeds 10% by weight, the lubricity will be too strong and the cleaning ability may be lowered.

Inorganic fillers such as calcium carbonate, magnesium carbonate, talc, silica, alumina and glass fibers can be added to the composition of the present invention, if necessary. Further, metal soaps such as calcium stearate, magnesium stearate and zinc stearate, and waxes such as carbane wax and polyethylene wax can be added.

The composition of the present invention can be obtained and is obtained by mixing the desired amounts of the thermoplastic resin, the neutral salt of alkylbenzene sulfonic acid and the basic magnesium stearate using a stir mixer. The mixture may be melt-kneaded at a temperature of 180 to 300 ° C., melt-kneaded and extruded to obtain pellets. Henschel mixer (trade name), super mixer,
A normal stirring and mixing device such as a tumbler or a ribbon blender may be used. As the extruder, a single screw extruder, a twin screw extruder, a cokneader, or the like can be used. Pelletization may be performed by cutting the extruded strand underwater, in the mist or in the air.

[0011]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited thereto.
In Examples and Comparative Examples, the cleaning ability of the cleaning thermoplastic resin composition was evaluated by the amount of the cleaning resin consumed and the time required for cleaning in the following cleaning test.

Cleaning Test A black flame-retardant polypropylene resin containing a halogen compound and antimony trioxide was extrusion-molded, and the flame-retardant polypropylene resin remained in the vessel in a single-screw extruder (cylinder diameter 35 mm, L The inside of the machine with / D of 30) was washed with 1 kg of the cleaning thermoplastic resin compositions obtained in Examples and Comparative Examples, respectively, and subsequently, a colorless polypropylene resin was used as a subsequent cleaning resin. A cleaning test is carried out by melt-kneading and extruding until the cleaning resin is no longer colored. The amount of the cleaning resin required until the cleaning resin is not colored and the time from the supply of the cleaning thermoplastic resin composition until the subsequent cleaning resin is not colored (hereinafter,
It is called cleaning time. ) To evaluate cleaning performance.

Example 1 Polypropylene resin (melt flow rate 5 g / 10 minutes)
4.1 kg (82% by weight), sodium dodecylbenzenesulfonate 0.7 kg (14% by weight), and basic magnesium stearate 0.2 kg (4% by weight) were put into a Henschel mixer with an internal volume of 20 liters, and stirring blades were added. Number of rotations of 50
Stir-mix for 3 minutes at 0 rpm. The obtained mixture is supplied to a twin-screw extruder (cylinder diameter 30 mm, L / D is 30), melt-kneaded and extruded at a cylinder temperature of 190 to 200 ° C. and a die temperature of 200 ° C., cooled in a water tank and cut with a pelletizer. To obtain a cleaning thermoplastic resin composition. A cleaning test was conducted using the obtained thermoplastic resin composition for cleaning. The amount of subsequent cleaning resin required was 2.5 kg and the cleaning time was 0.7 hours.

Comparative Example 1 Polypropylene resin (melt flow rate 5 g / 10 minutes)
Thermoplastic resin composition for cleaning 4.1 kg (82% by weight), 0.7 kg (14% by weight) of sodium dodecylbenzenesulfonate and 0.2 kg of polyethylene wax were melt-kneaded and extruded according to Example 1 and pelletized. Got A cleaning test was performed using the cleaning thermoplastic resin composition.
The amount of subsequent cleaning resin required was 8.0 kg and the cleaning time was 1.
It was 8 hours.

Example 2 Polystyrene resin (melt flow index 0.5 g /
10 minutes of homopolymer) 3.3 kg (66% by weight), potassium dodecylbenzene sulfonate 1.3 kg (26% by weight), basic magnesium stearate 0.4 kg (8% by weight) according to Example 1. Melt-kneading, extrusion, and pelletization were performed to obtain a cleaning thermoplastic resin composition. A cleaning test was conducted using the obtained thermoplastic resin composition for cleaning. The amount of subsequent cleaning resin required was 3.0 kg and the cleaning time was 0.8 hours.

Example 3 High density polyethylene resin (melt index 0.5 g /
According to Example 1, 4.5 kg (90% by weight) of 10 minutes homopolymer, 0.4 kg (8% by weight) of sodium dodecylbenzenesulfonate and 0.1 kg (2% by weight) of basic magnesium stearate were used. Melt-kneading, extrusion, and pelletization were performed to obtain a cleaning thermoplastic resin composition. A cleaning test was conducted using the obtained thermoplastic resin composition for cleaning. The amount of subsequent cleaning resin required was 4.0 kg and the cleaning time was 1.0 hour.

[0017]

The cleaning thermoplastic resin composition of the present invention comprises:
The resin used for molding adheres to the inside of the machine due to thermal decomposition or the like and is difficult to clean. This is a cleaning thermoplastic resin composition having extremely excellent cleaning ability for cleaning inside the molding machine. The use of a small amount of the cleaning thermoplastic resin composition of the present invention can significantly reduce the amount of subsequent cleaning resin used as compared with the conventional cleaning resin composition, and also shortens the cleaning time. can do.

Claims (3)

[Claims] 1. A cleaning thermoplastic resin composition comprising a thermoplastic resin, a neutral salt of alkylbenzene sulfonic acid and basic magnesium stearate. 2. A cleaning thermoplastic resin composition containing 45 to 95% by weight of a thermoplastic resin, 2 to 40% by weight of a neutral salt of alkylbenzene sulfonic acid, and 1 to 10% by weight of basic magnesium stearate. 3. The cleaning thermoplastic resin composition according to claim 1 or 2, wherein the thermoplastic resin is polypropylene, polyethylene, polybutene, poly-4-methylpentene or polystyrene.