JPS62195045A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:A detergent resin composition, containing a thermoplastic resin, neutralized salt of an alkylbenzenesulfonic acid and water repellent compound and used in a processing and molding machines for thermoplastic resins. CONSTITUTION:A composition obtained by blending (A) a thermoplastic resin, with (B) 2-30wt%, preferably 4-20wt% (based on the composition) neutralized salt of an alkylbenzenesulfonic acid, preferably sodium salt of a 6-16C alkylbenzenesulfonic acid and (C) 0.5-10wt% water repellent compound, preferably at least one selected from a metal salt of a higher fatty acid or composite metal soap thereof, liquid paraffin, synthetic wax, silicone and, as necessary, heat stabilizer, lubricant, plasticizer, etc., for molding. This composition is very effective for cleaning molding machines in changing over grades in plastic processing.

Description

DETAILED DESCRIPTION OF THE INVENTION (Object of the Invention) The present invention relates to a cleaning resin composition used in a thermoplastic resin processing and molding machine.

In plastic molding and processing, several measures are taken to eliminate the influence of previous products when changing products. Particularly in the processing of colored products, when changing the color from a dark-colored previous grade such as blue or black to a light-colored grade such as white, it requires complicated cleaning such as cleaning the inside of the molding machine with cleaning resin and disassembling and cleaning the processing molding machine. The reality is that the work and associated production have been forced to stop. Taking the case of color change in extrusion granulation molding as an example, after stopping the extruder and removing the screw, the screw and the inside of the cylinder must be cleaned by brushing, etc., and then the screw must be reinstalled. is necessary. The procedure of replacing the preceding product with a replacement resin to remove the screw requires a large amount of resin for cleaning, and the complicated structure inside the extruder cannot be cleaned (e.g., the subsequent product may become discolored). There are problems.Cleaning compounds are used to solve these problems.Cleaning compounds are used to help remove the residue in the extruder and complete the grade change using a small amount of replacement resin. There are cleaning compounds that contain lubricants such as stearic acid and those that use acrylic resin with a high melting temperature, but the former have insufficient cleaning effects, and the latter have odor. In addition to being strong, there are disadvantages such as making it difficult to reuse the replacement resin if it mixes with the replacement resin.Furthermore, since the latter has a high melt viscosity, it must be removed after removing the die, breaker plate, wire mesh, etc. The complexity of the work, such as the need to use cleaning compounds, remains unresolved.
Cleaning compounds containing glass fibers and the like still have drawbacks such as the inability to reuse the replacement resin and the wear and tear of the screws and cylinders of the molding machine.

In addition, a blend of powdered sodium alkylbenzene sulfonate and a replacement resin are used to clean the molding machine (two-phase cleaning is also carried out. However, since sodium alkylbenzene sulfonate is hygroscopic, compacted powder blended with this is also used). It is difficult to handle because it easily gets wet, and therefore crosslinks in the hopper of the molding machine, and the absorbed moisture reduces the cleaning effect.

As is clear from the above, the purpose of the present invention is to
It is an object of the present invention to provide a cleaning thermoplastic resin composition that can be used in combination with a small amount of a replacement resin to remove the resin of a previous type remaining in a processing molding machine with a simple operation.

(Structure of the Invention) As a result of various studies on cleaning methods for processing and molding machines, the inventors discovered that a thermoplastic resin composition obtained by mixing a neutral salt of alkylbenzenesulfonic acid and a water-repellent compound with a thermoplastic resin and granulating the mixture. The present invention has been completed based on the discovery that the above objects are excellent. That is, the present invention.

(1) A thermoplastic resin composition characterized by containing a thermoplastic resin, a neutral salt of an alkylbenzenesulfonic acid, and a water-repellent compound, and preferred embodiments thereof include the following items (2) to (4). is shown.

(2) The thermoplastic resin composition set forth in item (1) above, wherein the neutral salt of 1-alkylbenzenesulfonic acid is a sodium salt of an alkylbenzenesulfonic acid whose alkyl group has 6 to 16 carbon atoms.

(3) Item (1) or Item (2) (-), the content of the neutral salt of alkylbenzenesulfonic acid is 2 to 30% by weight, and the content of the water-repellent compound is 0.5 to 10% by weight. %
A thermoplastic resin composition.

(4) In any one of paragraphs (1) to (3) above, the water-repellent compound is selected from all groups of higher fatty acids or composite metal soaps thereof, wax-liquid paraffin, synthetic wax, and silicone. At least one thermoplastic resin composition.

Thermoplastic resins used in the composition of the present invention include polyolefins such as polyethylene, polypropylene/polybutene, and polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polystyrene, polyacrylonitrile, or copolymers thereof. Resin, ABS resin, MB8 resin, polyester resin, polyamide resin, etc. can be used alone or in combination of two or more.

As the neutral salt of alkylbenzenesulfonic acid, neutral salts of alkylbenzenesulfonic acid whose alkyl group has 6 to 16 carbon atoms can be used alone or in combination of two or more. Na salt is particularly preferably used as the neutral salt.

In addition, water-repellent compounds include fatty acids having 10 to 18 carbon atoms and their sodium salts, potassium salts, lithium salts, calcium salts, zinc compounds, or composite metal soaps thereof, waxes, liquid paraffin, synthetic waxes such as polyethylene wax, etc. , silicone, etc. can be used alone or in combination.

The content of alkylbenzene sulfonate in the composition is 2-
Preferably 30% by weight, more preferably 4 to 20% by weight
It is. Compositions with an alkylbenzene sulfonate content of less than 2% have a small cleaning effect, and compositions with an alkylbenzene sulfonate content of more than 30% result in significant foaming during the preparation and granulation stage. Both are unsuitable because they are extremely difficult to mold.

The content of the water repellent compound is preferably 0.5 to 10%. The water-repellent compound acts as a lubricant in the extruder when producing the thermoplastic resin composition of the present invention, but if the content is less than 0.5 inches, the lubricating effect will be small and foaming will become intense, making granulation impossible. . Furthermore, if the content of the water-repellent compound exceeds 10%, the lubricity is too strong, making it difficult to discharge a sufficiently blended compound during granulation, which is also not suitable.

The thermoplastic resin composition of the present invention may contain, in addition to the above-mentioned components, a heat stabilizer for molding, a lubricant, a plasticizer, etc. as necessary.

The thermoplastic resin composition of the present invention can be prepared by a conventional method for producing thermoplastic resin compositions.

- To give an example, a premixed composition is filled into the hopper of an extruder, the heated extruder (secondary extruder) discharges the molten composition, and strands are cut to obtain composition particles.

For mixing, a conventional mixer such as a Henschel type high-speed mixer, ribbon blender, tumbler, or gate mixer can be used depending on the type and shape of the resin. The thermoplastic resin used can be in the form of powder, beads, flakes, or pellets. The neutral salt of alkylbenzenesulfonic acid and the water-repellent compound can be in the form of powder, paste, liquid, or the like. The extruder is not particularly limited, and may include a single screw extruder, a twin screw extruder, a co-kneader, and the like.

The strands for granulation may be cut underwater or in the air.

(Example) Hereinafter, the present invention will be explained with reference to an example, but the present invention is not limited to these examples.

In Examples and Comparative Examples, the cleaning effect of the cleaning thermoplastic resin composition was determined by the amount of replacement resin consumed in the cleaning test conducted according to the following method and the amount of replacement resin dispensed after starting to supply the cleaning thermoplastic resin composition. Evaluation is based on the time it takes for the resin to fade (2).

Cleaning Test Method A contaminated thermoplastic resin composition containing phthalocyanine blue 2 as a coloring agent with an L/D of 3
0, feed 250ml of cleaning thermoplastic resin into a single screw extrusion molding machine with a cylinder diameter of 35mm, rotate the screw, and stop the rotation of the screw when the thermoplastic resin starts to be discharged from the die of the extruder. Pause briefly (1-5 minutes). Next, the same type of thermoplastic resin as that used in the cleaning resin composition is supplied for replacement, and the rotation of the screw is restarted, and the amount of replacement resin consumed until the discharged strand becomes colorless and the amount of color removed are determined. Measure the time it takes.

In another example, maleic anhydride is used instead of phthalocyanine blue as a contamination source, and the evaluation is based on the amount of replacement resin consumed and the time required until the characteristic pungent odor disappears.

Example 1 Polypropylene resin (Chissopolypro (registered trademark) K
1016) 4.5~, sodium decylbenzenesulfonate 0.45Kf, calcium stearate 0.05
V4 has an internal volume of 20I! Rotation speed 50 in a high speed mixer
Stirred for 3 minutes at Qrpm. This mixture has an L/D of 20
The strands are then fed to an extrusion granulator with a cylinder diameter of 20 cm. The strands are extruded under the conditions of a cylinder temperature of 200°C, a die temperature of 190°C, and a screw rotation speed of 5 Qrpn, cooled in a water bath, and cut with a pelletizer to form milky white granules. A thermoplastic resin composition was obtained.

Using the composition 4 days after granulation, a cleaning test was carried out on an extruder contaminated with the same type of polypropylene resin containing 2% phthalocyanine blue.

The temperature of the extruder cylinder was 220° C. After supplying the cleaning resin composition, the rotation of the extruder screw was temporarily stopped and the cleaning composition was left in the extruder for 5 minutes. The amount of replacement resin required was 0.5~.The time required for color change was 11 minutes.

Example 2 The cleaning composition granulated in Example 1 was left in a three-layer paper bag for 90 days, and then the same cleaning test as in Example 1 was conducted. The amount of replacement resin required to change the color was 0.5 mm, and the time required was 12 minutes.

Example 3 Maleic anhydride 2.5% instead of phthalocyanine blue
A cleaning test of an extruder contaminated in the same manner as in Example 2 was carried out in the same manner as in Example 2, except that the cylinder temperature was 190°C.

The amount of replacement resin required to extrude a discharge without a pungent odor was 0.3 kg, and the required time was 8 minutes.

Example 4 Polyethylene resin (Chisso Polyethylene (registered trademark) Ma2
O) 3.8 Kp,) Sodium lidenebenzenesulfonate 0.9 Kg, zinc stearate 0.2 kg, polyethylene wax (number average molecular weight 1500) O, 1 Kg
After mixing in the same manner as in Example 1, the cylinder temperature was set to 220
℃, die temperature 210℃, screw rotation speed 6 Orp
The mixture was fed to an extruder of 1.0 m to obtain milky white pellets.

25 of the cleaning resin composition 5 days after granulation was supplied to an extruder contaminated with a polyethylene resin containing phthalonanine blue 2, and the cylinder temperature was 230°C.
A cleaning test was conducted at 30°C and with the screw temporarily stopped for 3 minutes. The required amount of polyethylene resin for replacement was 0.3 to 7 minutes, and the required time was 7 minutes.

Example 5 Polystyrene resin (Non-chemical Styron 666)
4.7 Kf-) Sodium rifanbenzenesulfonate 0.2, zinc stearate 0.05, temperature 210°C, die temperature 200°C, screw rotation speed 6
Granulation was carried out in the same manner as in M1 1 at Orpm to obtain transparent pellets.

The above cleaning composition 33 days after granulation was fed into a cleaning test extruder contaminated with polystyrene resin containing phthalocyanine blue 20%, and cylinder salt iff 20
A cleaning test was conducted at 0°C and a screw pause time of 5 minutes. The required amount of replacement polystyrene resin is 1. OK
p. The time required for washing was 18 minutes.

Example 6 ABS resin (Stylac 200 made by non-chemical) 4.2
1'g, sodium tesilbenzenesulfonate 0.6h
s Liquid paraffin (ISOVG100 applicable product) 0. I
Kf and stearic acid 0. Example 3 using IKt
Granulation was carried out under the same extruder operating conditions as above to obtain milky white pellets. After 15 days, the pellets were used to perform a cleaning test on an extruder contaminated with the same type of ABS resin containing Phthalocyanine Blue 2. The results are shown in Table 1 together with the results of Examples 1 to 5.

Example 7 Polyvinyl chloride (Nipolit manufactured by Chisso ■ (Registered part m)
S'') 4.3 Kf-denrubenzenesulfonate sodium 0.4 Kf, caruncum stearate 0,
15 Kf and zinc stearate 0.15 KF, in the same manner as in Example 1. Cylinder temperature 180°C.
A slightly yellow pellet was obtained at a die temperature of 170°C. A cleaning test of an extruder contaminated with polyvinyl chloride containing 2% phthalocyanine blue was conducted using pellets aged 20 days. The washing operation conditions and results are shown in Table 1.

Example 8 The same cleaning test as in Example 2 was repeated and the discharged resin strands were cut to obtain pellets 560f. A cleaning test was conducted under the same extruder operating conditions as in Example 1 using a mixture of 150 t of these pellets and 100 f of cleaning pellets prepared in Example 2 and aged 90 days. The consumption amount of the replacement polypropylene resin was 0.6 kg, and the required time was 13 minutes.

Comparative Example 1 A cleaning test was conducted under the same conditions as in Example 1 except that the thermoplastic resin composition of the present invention was not used. As a result, the amount of replacement resin required for color change was 13. OK4, time was 1 hour 28 minutes.

Comparative Example 2 A cleaning resin mixture prepared using a high-speed mixer in the same manner as in Example 1 was packed into a three-layer paper bag without granulation and left indoors for 90 days.

A cleaning test was conducted using this mixture in place of the cleaning composition in Example 1. The amount of replacement resin required for the color change was 7.2 Kf, and the time required was 48 minutes.

Comparative Example 3 A cleaning test was conducted under the same conditions as in Example 3 except that the thermoplastic resin composition of the present invention was not used. The amount of replacement resin required for the color change was 5.2 Kf and the time was 30 minutes.

The results of the comparative example are shown in Table 1 as in the example.

(Effects of the Invention) By using the thermoplastic resin composition provided by the present invention, an extremely effective method for cleaning a molding machine during grade switching in plastic processing has been realized. That is, by using a small amount of the resin composition of the present invention, the amount consumed can be significantly reduced compared to the case where the molding machine is cleaned only by replacing it with resin supplied later. Taking the cleaning of an extrusion molding machine as an example, if the composition of the present invention is used in combination with the color change, compared to color change only by substitution,
The required amount of replacement resin can be reduced to 1/10 or less,
Further, the time required for color change can be reduced to 175 or less.

The composition of the present invention has water repellency, and its cleaning effect hardly decreases even after storage for 3 months, making it a cleaning composition with good storage stability that can withstand long-term storage.

In addition, when used to clean extruders contaminated with maleic anhydride-containing thermoplastic resins that emit specific odors, the amount of discharged material with strong odors can be greatly reduced, and the time required for grade changeover can also be shortened. This has the ripple effect of improving the work environment.

Furthermore, the replacement resin that has been used once can be used as a part of the cleaning resin, and the possibility of reusing the replacement resin can be expected.

Patent applicant Chisso Co., Ltd. Company agent Patent attorney Yatabe Sasai Same as above Katsuhiko Nonaka

Claims (4)

[Claims] (1) A thermoplastic resin composition comprising a thermoplastic resin, a neutral salt of an alkylbenzenesulfonic acid, and a water-repellent compound. (2) In claim (1), the neutral salt of an alkylbenzenesulfonic acid has an alkyl group having 6 carbon atoms.
A thermoplastic resin composition which is a sodium alkylbenzenesulfonate having a formula of 16 to 16. (3) In claim (1) or (2), the content of the neutral salt of alkylbenzenesulfonic acid is 2.
~30% by weight, and the content of water repellent compound is 0.5~1
0% by weight of a thermoplastic resin composition. (4) In any one of claims (1) to (3), the water-repellent compound is selected from higher fatty acid metal salts or composite metal soaps thereof, waxes, liquid paraffins, synthetic waxes, and silicones. at least one thermoplastic resin composition.