JPH02206636A - Resin composition for cleaning - Google Patents

Abstract

PURPOSE:To provide the subject resin composition containing a composition prepared by blending PS with a neutral salt of an alkylbenzensulfonic acid and a mold release compound and useful for cleaning a machine in item change of engineering plastics molded at high temperatures. CONSTITUTION:An objective composition containing a composition prepared by blending (A) preferably 50-95wt.% PS [preferably <=7.0 melt flow index (g/10min)] with (B) preferably 2-40wt.% neutral salt of an alkylbenzensulfonic acid and (C) preferably 1.5-15wt.% mold release compound (preferably pentaerythritol tetracarboxylate where carboxylic acid has 10-22C, borate of glycerin monocarboxylate where carboxylic acid has 12-22C, etc.).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cleaning resin composition for use in a thermoplastic resin molding machine when the resin gets sick.

[Conventional technology]

In plastic molding and processing, when changing products, several measures are taken to eliminate the influence of the previous product.

Particularly in the processing of colored products, when switching from dark-colored grades such as blue and black to light-colored grades such as white, complicated work such as disassembling and cleaning the molding machine and cleaning the inside of the molding machine with cleaning resin is required. The reality is that we are forced to suspend production due to this.

For example, when changing extrusion granulation molding, it is necessary to stop the extruder, remove the screw, clean the inside of the screw and cylinder by brushing, etc., and then reinstall the screw. Using resin to replace the preceding product without removing the screw requires multiple layers of resin for cleaning, and the inability to remove dirt from the complex structure inside the extruder may result in coloring of the subsequent resin. There are problems such as the occurrence of One way to solve these problems is to use a cleaning compound to easily remove the residue inside the extruder, and use a small amount of replacement resin to change product types.

The present inventors previously discovered in Japanese Unexamined Patent Publication No. 1985-1950 that a thermosetting resin composition consisting of a thermoplastic resin, a neutral salt of alkylbenzenesulfonic acid, and a water-repellent compound has excellent cleaning ability. Disclosed.

[Problem to be solved by the invention]

When changing types of engineering plastics that are processed at high temperatures, such as polyphenylene oxide, polyphenylene sulfide, polybutyl terephthalate, fluororesin, and nylon, it is necessary to develop compounds with even better cleaning performance than conventional ones.

An object of the present invention is to provide a cleaning resin composition that uses an ecological replacement resin to allow removal of previous products remaining in a molding machine for engineering plastics processed at high temperatures with a simple operation. It is to be.

[Means to solve the problem]

As a result of various studies on cleaning methods for molding machines, the present inventors found that
The present invention was completed based on the discovery that a granulated composition obtained by mixing polystyrene, a neutral salt of alkylbenzenesulfonic acid, and a mold release compound has excellent cleaning ability at high temperatures.

That is, the present invention is a cleaning resin composition containing a composition in which polystyrene is blended with a neutral salt of alkylbenzenesulfonic acid and a mold release compound.

The blending ratio is 50 to 95% by weight of polystyrene,
A cleaning resin composition containing 2 to 40% by weight of a neutral salt of alkylbenzenesulfonic acid and 1.5 to 15% by weight of a releasing compound.

For polystyrene, melt flow index (!
? /10 minutes) (JISK6870) is preferably 7.0 or less. If it exceeds 7.0, the fluidity will be too strong and it will be difficult to peel off the preceding engineering plastic, which is not preferable.

The releasing compound is preferably one that does not decompose or volatilize at a Fi4 temperature of 200°C or higher, such as pentaerythritol tetracarboxylic acid ester in which the carboxylic acid has 10 to 22 carbon atoms, or a carboxylic acid in which the carboxylic acid has 12 to 22 carbon atoms. One or more types selected from the group consisting of boric acid esters of monoglycerides, calcium salts of boric acid esters of carboxylic acid monoglycerides whose carboxylic acid has 12 to 22 carbon atoms, polyethylene wax, and silicone oil can be mentioned.

The neutral salts of alkylbenzenesulfonic acids used in the compositions of the present invention include sodium salts, potassium salts, magnesium salts, and calcium salts. The amount of the neutral salt of alkylbenzenesulfonic acid used is preferably 2 to 40% by weight.

If the ratio is less than 2%, the cleaning ability at high temperatures will be small;
If the amount used exceeds 40% by weight, the fluidity will be too strong and it will be difficult to peel off the preceding engineering plastic, which is not preferable.

The composition of the present invention includes MS resin, MBS resin, ABSs
It can contain soubrene-based copolymers such as L resin, As resin, and BS resin. Also calcium carbonate, talc,
Inorganic fillers such as silica, alumina, glass fiber, etc. can be added. Furthermore, metal soaps such as magnesium stearate, calcium stearate, and zinc stearate,
Heat stabilizers such as bisphinol A, dibutyltin malate,
Alkyl ether 1iXBI! Anionic surfactants such as sodium ester and sodium alpha olefin sulfonate can also be added.

141 of the composition of the present invention! This can be done in the following way.

A hopper of an extruder is filled with the premixed composition, the molten composition is discharged from the heated extruder, and the strands are cut to obtain a pelletized composition.

For mixing, a conventional mixer such as a Henschel type high-speed mixer, a ribbon blender, or a tumbler can be used depending on the type and shape of the resin.

The shape of the resin used may be powder, beads, flakes, pellets, etc. For extrusion, a single screw extruder, twin screw extruder, co-kneader, etc. can be used. The cutting method for granulation may be underwater cutting, mist cutting, or aerial cutting.

(Example) 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 effects of the compositions are evaluated by the amount of displacing resin consumed and the time required for cleaning in a cleaning test using the following method.

Cleaning Test A 35 ton injection molding machine is used to feed precursor resin 3009 containing 1% by weight carbon black. Next, 100 g of a composition for cleaning is supplied, and a replacement resin is further supplied, and injection molding is repeated until the discharged resin disappears in color. The amount of the replacement resin consumed and the time from supplying the composition until it disappears is measured.

(Example 1) Polystyrene (melt flow index (JISK6
870: 200℃, 5? (fff)1. Of/lo
Is gin homopoly? -) 3.90Kg, sodium dodecylbenzenesulfonate 0.5ONy, boric acid ester of stearic acid monoglyceride 0.40Kg, polyethylene wax (number average molecule f! 11500) 0.10
Phantom, magnesium stearate 0.10 at 5F in a high speed mixer with an internal volume of 20Jl at a rotation speed of 50Orpm.
Mix by stirring for a minute.

This mixture was supplied to a two-wheel screw extruder with a cylinder L/D of 30 and a cylinder diameter of 30 m, and the strands were extruded at a cylinder temperature of 220°C and a die temperature of 230°C, cooled in a water tank, and cut with a pelletizer. A milky white, granular composition was obtained. This composition was used in a cleaning test on an injection molding machine contaminated with polyphenylene oxide containing 1% carbon black.

The cylinder temperature of the injection molding machine was 280°C, and polyethylene terephthalate was used as the replacement resin. The amount of polyethylene terephthalate consumed was 140 g, and the time required for washing was 12 minutes.

(Example 2) Polystyrene [melt flow index (J l5K
6870: 200℃, 5Kyf) 1.0g/10a
iin homopoly'? -) 4.55 Ny, magnesium dodecylbenzenesulfonate 0.25 Kg, silicone oil (viscosity (25°C) 500 centistokes > 0.
15kg, 1-lium dodecylsulfonate 0.05N
y, were mixed in the same manner as in Example 1.

A composition was obtained in the same manner as in Example 1 except that the cylinder temperature was 230°C and the die temperature was 240°C. This composition was used in a cleaning test on an injection molding machine contaminated with polycarbonate containing 1% by weight of carbon black. The cylinder temperature of the injection molding machine was 260° C., and polystyrene was used as the replacement resin. The consumed layer of polystyrene was 1809, and the time required for washing was 14 minutes.

(Example 3) Polystyrene (melt flow index (JISK6)
870: 200℃, 5kgf)i, 89/10w1
In the same manner as in Example 1, 3.1 ONp (homopolymer of n), 1.60 Kg of potassium dodecylbenvinsulfonate, 0.20 Kg of polyethylene wax (number average molecule 11,500), and 0.10 Kg of magnesium stearate were mixed. A composition was obtained in the same manner as in Example 1 except that the cylinder temperature was 190°C and the die temperature was 200°C. This composition was used to perform a cleaning test on an injection molding machine contaminated with polyphenylene sulfide containing 1% carbon black. The cylinder temperature of the injection molding machine is 300℃,
In addition, polyacetal was used as the substitution resin. The amount of polyacetal consumed was 260, and the time required for cleaning was @i! l
was 18 minutes.

(Example 4) Polystyrene [melt flow index (J l5K
6870: 200℃, 5Kyf) 5.2SF/10
Homopoly of m1n? -) 4.50! g, calcium dodecylbenzenesulfonate 0.15Ny, calcium borate of palmitic acid monoglyceride F0
．． 15Kg, polyethylene wax (number average molecule ff1
l 500) 0.1 ONy, alumina (Sumitomo Chemical ■
AL-32) 0.1 ONg was mixed in the same manner as in Example 1. A composition was obtained in the same manner as in Example 1 except that the cylinder temperature was 190°C and the die temperature was 200°C. Using this composition, a cleaning test was carried out on an injection molding machine contaminated with polyphenylene oxide containing 1 mm% of carbon black. The cylinder temperature of the injection molding machine was 280° C., and ABS resin was used as the replacement resin.

The amount of ABS resin consumed was 320g, and the time required for cleaning was 2
It was 1 minute.

(Example 5) Polystyrene C melt flow index (J l5K
6870: 200℃, 5Kgf) 5.2g/10m
1n homopoly? -) 4.10 kg, sodium dodecylbenzene sulfonate 0.7589, pentaerythritol tetrastearate 0.10 kg, and magnesium stearate 0.05 kg were mixed in the same manner as in Example 1.

A composition was obtained in the same manner as in Example 1 except that the cylinder temperature was 190°C and the die temperature was 200°C. This composition was used in a cleaning test on an injection molding machine contaminated with polyphenylene oxide containing 1% by weight of carbon black. The cylinder temperature of the injection molding machine was 280° C., and polyethylene terephthalate was used as the substitute @4 resin. The consumption amount for polyethylene terephthalate 1 is 300g,
The time required for cleaning was 20 minutes.

(Comparative Example 1) Polystyrene (melt flow index (J l5K)
687 (5: 200℃, 5/(gf)5.2g/10
m1n homopolymer] 4.80 Kg, sodium dodecylbenzenesulfonate 0.057 (9, pentaerythritol tetrastearate 0.101'i9, magnesium stearate 0.058 y) were mixed in the same manner as in Example 1. Cylinder temperature 1 meal 190℃, dice temperature 20
A composition was obtained in the same manner as in Example 1 except for the temperature of 0°C. Using this composition, a cleaning test was carried out on an injection molding machine contaminated with polyphenylene oxide containing 1% carbon black 1f4ff. Injection molding machine cylinder temperature 2
The temperature was 80° C. and polyethylene prephthalate was used as the replacement resin. The amount of polyethylene terephthalate consumed was 1220 g, and the time required for washing was 66 minutes.

(Comparative Example 2) Polystyrene [melt flow index (J l5K
6870: 200℃, 5/(yf>23.09/1
0+tn ho [poly? -) 4.10 to 9, sodium dodecylbenzenesulfonate 0.75Kg, pentaerythritol tetrastearate 0. IC1 and 0.05 kg of magnesium stearate were mixed in the same manner as in Example 1. A composition was obtained in the same manner as in Example 1 except that the cylinder temperature was 190°C and the die temperature was 200°C.This composition was used in an injection molding machine contaminated with polyphenylene oxide containing 1% by weight of carbon black. A cleaning test was conducted at an injection molding machine cylinder temperature of 280°C.
Moreover, poly(1-ethylene terephthalate) was used as a substitute resin. The consumption of polyethylene terephthalate is 920
g. The time required for washing was 51 minutes.

The conditions and results of Examples 1 to 5 and Comparative Examples 1 to 2 are summarized in Table 1.

〔Effect of the invention〕

By using the composition of the present invention for cleaning, it was possible to realize a very effective method for changing types of engineering plus books that are molded at high temperatures.

That is, by using a small amount of the resin composition of the present invention, the amount of subsequent replacement resin can be significantly reduced and the cleaning time can be shortened, compared to the use of conventional cleaning compositions. Table 1
For example, when switching from polyphenylene oxide to polyethylene terephthalate, the amount of replacement resin used was reduced to less than one-third, and the cleaning time was also shortened to less than 215%.

Claims (1)

[Claims] 1. A cleaning resin composition containing a composition prepared by blending polystyrene with a neutral salt of alkylbenzenesulfonic acid and a mold release compound. 2. A cleaning resin composition comprising 50 to 95% by weight of polystyrene, 2 to 40% by weight of a neutral salt of alkylbenzenesulfonic acid, and 1.5 to 15% by weight of a releasing compound. 3. Polystyrene has a melt flow index (g/1
3. The cleaning resin composition according to claim 1 or 2, wherein the cleaning resin composition has a water resistance of 7.0 (JIS K6870) or less. 4. The mold release compound has a carboxylic acid having 10 to 22 carbon atoms.
Pentaerythritol tetracarboxylic acid ester, boric acid ester of carboxylic acid monoglyceride with carboxylic acid having 12 to 22 carbon atoms, carboxylic acid having 12 to 22 carbon atoms
Claim 1: One or more selected from the group consisting of calcium salt of boric acid ester of carboxylic acid monoglyceride No. 22, polyethylene wax, and silicone oil.
Or the cleaning resin composition according to 2.