JP2774922B2 - Cleaning composition for plastic processing machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cleaning composition for a plastic processing machine.

[0002]

2. Description of the Related Art Thermoplastic resins are widely used in injection-molded products, extruded products, films and the like, utilizing their excellent moldability. Since these plastic molded articles tend to be produced in a large number of kinds and in a small quantity, and the frequency of changing the kinds is increasing, cleaning in the molding machine at the time of changing the kinds is becoming important in quality control. In the molding of plastics, the following several measures have conventionally been taken at the time of product type change in order to eliminate the influence of the preceding product type. (1) There is a method of disassembling and cleaning the processing and molding machine, but this method is very time-consuming, and in a large-sized molding machine, there is a danger because large parts are lifted and lowered. For example, in the case of color change in extrusion granulation, for example, it is necessary to stop the extruder, pull out the screw, wash the inside of the screw and cylinder by brushing, etc., and then install the screw again It is. (2) Next, there is a method of washing with a resin to be used subsequently, that is, a preceding product is replaced with a replacement resin without removing a screw. In this treatment, a large amount of resin needs to be flown for washing, and there is a problem that coloring of a succeeding product is caused because dirt on a complicated structural portion in the extruder cannot be removed. (3) There is a method of using a cleaning compound to solve these problems. The purpose of the present invention is to make it easy to remove the residue in the extruder by using a washing compound, and to complete the grade switching by using a small amount of a replacement resin. Cleaning compounds include those containing lubricants such as stearic acid, and those using hard acrylic resin.
The former has an insufficient cleaning effect, and the latter has a strong odor.In addition, since it is used in a semi-molten state, the load increases and the dies, breaker plates, wire mesh, etc. must be removed before using the cleaning compound. The complexity of the workplace, such as the need to work, remains unresolved.

(4) Japanese Patent Application Laid-Open No. 62-62
JP 195045 discloses a composition comprising a thermoplastic resin, sodium alkylbenzenesulfonate and a water-repellent compound. JP-A-63-66245 discloses a thermoplastic resin, a sulfonic acid neutral salt and a particle size of 0.1. 05-10
A composition comprising a μm powdery inorganic compound is disclosed as a cleaning composition. There is also U.S. Pat. No. 4,838,945 in which these are combined. Further, U.S. Pat. No. 4,838,948 discloses a method for cleaning resin processing equipment with polyethylene, calcium carbonate and a sulfonate activator. However, these methods increase the amount of subsequent resin used to completely discharge the detergent depending on the type of resin and the method of use,
After all, there is an example that is not much different from the method (2). Many of these compositions are obtained by adding a detergent to a thermoplastic resin, and there are many problems in adding a large amount of the detergent. For example, many of these compositions are usually pelletized in an extruder, but cannot be extruded earlier due to low shear friction with the extruder screw. Extruders with vents have problems such as the fact that the strands cannot be pulled out due to the so-called vent-up phenomenon, which blows out from the vent port, making pelletization impossible. Further, in a cooling method using water such as an underwater cut method, the cleaning agent dissolves in the water, and a large amount of the cleaning agent flows into the drainage to cause a drainage problem.

[0004] In the field of use where the prior art is weak, the preceding resin is an opaque resin or a dark-colored resin, and the following resin is required to have transparency, and the cleaning agent hinders the transparency of the subsequent resin. And it remains as a white streak forever. Extrusion blown films, T-die films, and injection molded hot runner molds are fields in which cleaning is difficult, and in practice, the above-mentioned composition (4) is rarely used in these fields. JP-A-4-978 by the present applicant
No. 05 discloses a composition for solving the above-mentioned problems. However, when the composition is used for cleaning, ABS
When an aromatic resin such as a resin, a flame-retardant ABS resin, or a polycarbonate is the subsequent resin, it remains in the subsequent resin and impairs the appearance of the product.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems of the prior art, and it is an object of the present invention to provide a plastic processing method which does not remain in a resin to be subsequently used and does not impair the appearance of a subsequent product. It is to provide a mechanical cleaning composition.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a specific resin, a detergent comprising a surfactant and an inorganic substance,
The inventors have found that a specific composition of polyphenols achieves the object, and have completed the present invention. That is,

The cleaning composition for a plastic processing machine of the present invention comprises an acrylonitrile-styrene resin (hereinafter, referred to as an AS resin), an acrylonitrile-butadiene-styrene resin (hereinafter, referred to as an ABS resin), a methacryl-styrene resin (hereinafter, an MS resin). At least one resin selected from the group consisting of methacryl-butadiene-styrene resin (hereinafter, referred to as MBS resin) and a detergent consisting of a surfactant and an inorganic substance.
% By weight and 1 to 10% by weight of polyphenol. Further, those further processed in the form of pellets are preferable.

[0008] The cleaning resin mixture for a plastic processing machine of the present invention comprises an AS resin, an ABS resin, an MS resin and an MBS.
At least one resin 15 selected from the group consisting of resins
Detergent consisting of a surfactant and an inorganic substance of up to 40% by weight 8
4-50% by weight and 1-10% by weight of polyphenol
3 to 30% by weight of pellets of the above-mentioned cleaning composition containing
And 97 to 70% by weight of general-purpose pellets of AS resin, ABS resin, MS resin or MBS resin.

The resin used in the composition of the present invention is at least one selected from the group consisting of AS resin, ABS resin, MS resin and MBS resin. The content ratio of the resin in the composition is 15 to 40% by weight. When the content is less than 15% by weight, the compound does not become entangled with the rotor and cannot be pelletized because a uniform mixed state cannot be obtained.
If the amount is more than 100% by weight, the amount of the cleaning composition must be increased when cleaning the plastic processing machine due to a decrease in the amount of the cleaning component.

The detergent used in the composition of the present invention comprises a surfactant and an inorganic substance.
A commercially available product mixed with 0% by weight can be used, and may be separately measured and added. The content of the cleaning agent in the cleaning composition is 84 to 50% by weight. If the amount is more than 84% by weight, the resin cannot be entangled due to a small amount of the resin, and a uniform mixing state cannot be obtained. If the amount is less than 50% by weight, the amount of the cleaning composition used in cleaning the plastic processing machine must be increased, which is not preferable.

As the surfactant, a neutral salt of dodecylbenzenesulfonic acid which is an anionic surfactant, a neutral salt of α-olefinsulfonic acid having 8 to 20 carbon atoms, or
Examples thereof include alkyl sulfate neutral salts having 6 to 20 carbon atoms and fatty acid salts having 12 to 20 carbon atoms, and these may be used as a mixture.

As inorganic substances, sodium sulfate, bentonite, zeolite, calcium silicate, kaolin, diatomaceous earth, silicon dioxide, white carbon, pumice powder,
Examples include volcanic ash and aluminum silicate, and two or more of these may be used as a mixture. The content of the inorganic substance in the detergent is preferably 10 to 40% by weight. These minerals are
Enhance the bulking and cleaning effect.

The polyphenols used in the composition of the present invention include hydrolyzable tannins and condensed tannins.
1 to 10% by weight is added. When the polyphenol is used as a cleaning composition with an addition amount of 1% by weight or less, it is not preferable to use the cleaning composition since it adheres to the screw and remains. Conversely, if the content is 10% by weight or more, the lubricating property is too strong, and when used as a component of the cleaning composition, the resin is extruded from the cylinder without removing the preceding resin, which is not preferable.

In the production of the composition of the present invention, it is preferable to knead the resin, the detergent and the polyphenol with a Banbury mixer or a pressure kneader. It is convenient that the mass compound after kneading is processed into a sheet by a roll and then pelletized by a sheet cutting method, an air-cooled conveyor method, or the like. 1. MFR after kneading of the cleaning composition (230 ° C. 2.
16 kg) is preferably from 0.5 to 15, and if it is too low, the cleaning composition remains when washing the plastic processing machine and comes out to the subsequent resin, which is a problem. If it is too high, stickiness becomes a problem.

[0015] The composition of the present invention can be used in the same molding machine such as an injection molding machine when exchanging resins or changing colors.
3 ~ for general purpose pellets of BS resin, MS resin and MBS resin
Even if it is mixed (dry-blended) by about 30% as a cleaning resin mixture, sufficient cleaning performance is exhibited. If the addition amount is less than 3%, the cleaning effect is small, and if the mixing amount exceeds 30%, the lubricity during cleaning is so strong that the adhered dirt cannot be removed. In addition, the dry blend mixture of the present invention can change the blend ratio according to the hardness and coloring state of the preceding resin, so that the economic effect can be enhanced.

[0016]

EXAMPLES Hereinafter, the cleaning composition and the cleaning resin mixture of the present invention will be described with reference to Examples and Comparative Examples. The obtained composition was evaluated by the following test method. Granulation (pellet forming performance): The cleaning composition was formed into a sheet with a roll, cooled to about 40 ° C., pelletized with a square pelletizer, and evaluated next. ◎ = Sheet can be rolled and square pellets can be formed with a sheet cutter. ○ = Sheets can be rolled, and the pellets are slightly crushed by the sheet cutter. × = Sheet rolls can be managed, but square pellets cannot be obtained with a sheet cutter. Cleaning performance: Using an M150II type injection molding machine manufactured by Meiki Seisakusho Co., Ltd., the cylinder temperature was set to 250 ° C., and ABS resin [MFR = 9: Nippon Synthetic Rubber Co., Ltd. “JSR ABS45”] After flowing 3 kg of the black-colored product (carbon black concentration: 1%), and then using ABS resin [manufactured by Nippon Synthetic Rubber Co., Ltd .: "JSR ABS"
The injection molding machine was washed with 500 g (for 5 shots) of a washing resin mixture obtained by dry-blending 59 ”] and a predetermined amount of cleaning composition (see the table). Then, the subsequent ABS resin [manufactured by Nippon Synthetic Rubber Co., Ltd.] : "JSR ABS59"]
And injection molding was performed, and the following rank was evaluated according to the amount of the ABS resin used until the black color of the molded product disappeared and a good product was obtained. ◎ = 1 kg or less ○ = 1.1 to 2 kg △ = 2.1 to 3 kg × = 3.1 kg or more XX = (blank 5.2 kg)

The abbreviations in the tables of the resins, surfactants and inorganic substances used in the compositions of the examples and comparative examples are as follows. AS: “Sanlex SAN-H” manufactured by Mitsubishi Kasei Corporation MFR = 6.
5 (J-K7210) ABS: Nippon Synthetic Rubber Co., Ltd. “JSR ABS59” MFR = 5.0 MS: Nippon Steel Chemical Co., Ltd. “Estyrene MS300” MF
R = 1.3 MBS: "METABLEN C-201" manufactured by Mitsubishi Rayon Co., Ltd. Polyphenol: "Hi tannic acid" manufactured by Dainippon Pharmaceutical Co., Ltd. Surfactant A: Sodium dodecylbenzenesulfonate B: Sodium α-olefin sulfonate C: Lauric sulfate D: Sodium stearate Inorganic a: Sodium sulfate b: Zeolite c: Diatomaceous earth d: Kaolin

Example 1 The rotor and jacket of an MS-type pressurized kneader (Moriyama Seisakusho Co., Ltd.) having an internal volume of 3 liters were heated to 130 to 145 ° C. by oil heating, and MBS resin [Mitsubishi Rayon Co., Ltd.] "METABLEN C201"] 1.2 kg, sodium dodecylbenzenesulfonate 60 parts by weight and sodium sulfate 40 parts by weight 2.4 kg, polyphenol 0.4 kg
Is charged into the pressure lid to 500 kg with air, and the kneader rotor is rotated to knead. After about 10 minutes, the pressure lid was raised to remove water, and the pressure was again applied with the pressure lid and kneaded for 2 to 3 minutes to obtain a cleaning composition for a plastic processing machine. This was formed into a sheet with a roll, cooled to about 40 ° C., and a cleaning composition for a plastic processing machine pelletized by a square pelletizer was obtained. 10 parts by weight of this cleaning composition and an ABS resin to be used subsequently [manufactured by Nippon Synthetic Rubber Co., Ltd .: “JSR
ABS59 ″] was dry blended to obtain a cleaning resin mixture. The test results are shown in Table 1.

Examples 2 to 5 The same procedures as in Example 1 were carried out except that the composition was changed as shown in Table 1. Table 1 shows the test results.

Examples 6 and 7 The same procedure as in Example 1 was carried out except that the content of the composition in the cleaning mixture was changed. Table 1 shows the results.

Comparative Examples 1 and 2 Compositions containing detergents and polyphenols outside the scope of the present invention were obtained in the same manner as in Example 1. Table 1 shows the test results.

Comparative Example 3 No cleaning composition was used, and only "JSR ABS59" was used as a cleaning resin mixture. It took 5.2 kg to obtain a good non-defective resin as a result of the test.

[0023]

[Table 1]

Comparative Example 4 MBS resin (manufactured by Mitsubishi Rayon Co., Ltd .: Metablen C20)
1) 4.0 kg, 0.8 kg of a mixture of sodium dodecylbenzenesulfonate and disodium sulfate, tannin 0.2
kg in a 20L high-speed mixer with 500 rpm
For 3 minutes. The mixture was fed to an extruder having an L / D of 20 and a cylinder diameter of 20 mm, and a cylinder temperature of 19 mm.
0 ° C, die temperature 180 ° C, screw rotation speed 60rpm
The strand was extruded under the conditions described above, cooled in a water bath and cut with a pelletizer to obtain a milky white pellet composition.
The composition was tested as such as a cleaning resin mixture. It took 2.5 kg of the succeeding resin until a good product was obtained.
(Table 2)

[0025]

[Table 2]

As shown in the examples, ABS having good transparency
When the resin was flowed as the subsequent resin, a non-defective product was obtained at a stage where the amount of the resin was reduced to 1/2 to 1/4 of the conventional method (Comparative Example 4). As described above, the composition of the present invention can be used as a cleaning resin mixture by mixing with the resin to be used subsequently, and the mixing of 3 to 30% of the subsequent resin can sufficiently clean the molding machine. The sum of the amount of the product and the subsequent resin, that is, the cleaning resin mixture is 1/2 to 1/1 / that of the conventional processing machine cleaning agent.
It becomes 4. If it is performed by the conventional disassembly and cleaning method, it takes 10 to 15 times as long. As described above, by flowing a small amount of the cleaning resin mixture obtained by mixing 3 to 30% of the cleaning composition with the subsequent resin, the time required for cleaning is reduced,
The effect was obtained that the amount of subsequent resin flowing until a good product was obtained could be reduced. Add the composition of the present invention to a general-purpose resin in 3 to 3
By mixing 0% by weight, better cleaning performance was obtained than the composition obtained by the processing method according to the prior art shown in Comparative Example 2. In addition, the composition of the present invention can be added to a general-purpose resin according to the ease with which the resin used in advance to be cleaned adheres to the screw and the coloring concentration. That is, in the case of a precedent resin which is easy to wash, such as a light gray color, the addition amount may be small. In addition, when washing a pre-colored resin which is difficult to remove such as phthalocyanine blue, the amount of addition may be increased.

[0027]

The cleaning composition of the present invention can be mixed with a resin for subsequent use to clean the molding machine, so that the time required for cleaning and the amount of subsequent resin used for cleaning can be reduced.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C08L 55/02 C08L 55/02 C11D 3/20 C11D 3/20 17/00 17/00 (58) Investigated field (Int.Cl. . ^6, DB name) C11D 3/14 - 3/38 C08K 5/13 C08L 25/14 C08L 33/12 C08L 33/20 C08L 55/02 C11D 3/20 CA (STN)

Claims (3)

(57) [Claims] At least one resin selected from the group consisting of acrylonitrile-styrene resin, acrylonitrile-butadiene-styrene resin, methacryl-styrene resin and methacryl-butadiene-styrene resin.
A cleaning composition for a plastic processing machine, comprising 5 to 40% by weight, 84 to 50% by weight of a detergent comprising a surfactant and an inorganic substance, and 1 to 10% by weight of a polyphenol. 2. The cleaning composition for a plastic processing machine according to claim 1, which is processed into pellets. 3. A general-purpose pellet of acrylonitrile-styrene resin, acrylonitrile-butadiene-styrene resin, methacryl-styrene resin or methacryl-butadiene-styrene resin in an amount of 97 to 70% by weight and a pellet of the composition according to claim 2 in an amount of 3 to 30% by weight. % Cleaning resin mixture for plastic processing machines.