JP2007021765A - Washing resin composition for molding machine and washing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a washing resin composition capable of simply performing the substitution with a post-resin and the removal of foreign matter with respect to a resin easy remaining in a molding machine, enhanced in purging/washing effect even if the use amount of a detergent is little, suppressing the adhesion to the inner surface of the molding machine at a washing temperature and capable of rapidly performing the substitution with the post-resin by easily discharging the detergent itself from the molding machine. <P>SOLUTION: The washing resin composition of the molding machine comprises 0.1-100 pts.wt. of a polyalkylene oxide or polyalkylene glycol (C) with a viscosity average molecular weight of 10,000-1,500,000 and 0.1-10 pts.wt. of an anionic surfactant being a sulfate or sulfonate having a 8-20 C alkyl group and/or a metal salt of a 6-22C fatty acid (D) based on the 100 pts.wt. of a mixture of 20-99 wt.% of an olefinic thermoplastic resin (A) and 1-80 wt.% of an unsaturated group-containing carboxylic acid modified olefinic resin (B). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a resin composition for washing a molding machine, and a method used for purging or washing away residual resin or foreign matters and quickly replacing them with a post-resin. In more detail, it is possible to prevent the occurrence of flaws during molding, or to reduce the occurrence of flaws by using a small amount when a flaw occurs. When discharging the cleaning agent itself during cleaning, The present invention relates to a molding resin cleaning resin composition having excellent substitution and low contamination, and a molding machine cleaning method using the same.

General-purpose thermoplastic resins such as polyvinyl chloride resin, styrene resin, olefin resin, etc., thermoplastic elastomers such as ethylene / vinyl acetate copolymer, ethylene / acrylic acid ester copolymer, ionomer, and PET, PBT, PC, etc. General-purpose engineering plastics are used in many fields by taking advantage of their characteristics. These resins are excellent in moldability and are used in various applications. When replacing these resins, it takes time to replace the resin, a large amount of resin is required for replacement, and further, the resin replacement takes a long time and remains in the next resin as contamination, etc. There was a problem that cost and time were wasted. In particular, thermoplastic elastomers such as ethylene / vinyl acetate copolymers, ethylene / acrylic acid ester copolymers, and ionomers are extremely sticking to the screw, and a large amount of purge resin is required at present. There is a demand for a method of easily replacing the resin with a small amount of resin after use.
Moreover, these resin which adheres easily accumulates and stays in a molding machine, and they cause a flaw. Once these irregularities are generated, it is necessary to stop the extruder and remove the causative agent, or to clean the molding machine with a solvent. Productivity declined.
For this reason, the molding machine is cleaned by melting a thermoplastic resin containing an abrasive and removing foreign matter adhering to the cylinder or screw (Patent Document 1), and by melting a resin containing a surfactant and an inorganic compound. Or the method (patent documents 2 and 3) of removing the foreign material adhering to a screw, the resin composition for washing | cleaning (patent document 4) which consists of resin containing an inorganic filler and a foaming agent are known.
That is, the conventional cleaning method is mainly a method of mechanically scraping the molding machine surface using a glass fiber or alumina kneaded into a resin with high viscosity.
Since these methods mechanically scrape off the adhered resin, the foreign matter prevention effect is poor unless the conditions in the molding machine are uniform, and the cleaning agent itself has a high viscosity, so that it tends to remain in the molding machine after washing. It sometimes hurt the molding machine.
Further, a cleaning material composed of a thermoplastic resin and a foaming agent is also known. For example, in a cleaning material for a resin molding machine heating tower (Patent Document 5), a thermoplastic resin having an appropriate compatibility with the resin to be cleaned is a residue. It is thought to be washed by adhering to or extruding. In addition, the cleaning agent (Patent Document 6) describes that the cleaning effect is improved by adjusting the meltability of the resin. Further, a molding machine cleaner made of a specific thermoplastic resin and water (Patent Documents 7 and 8) is also known, but in these methods, the type and meltability of the thermoplastic resin must be changed depending on the type of resin to be cleaned. There is a problem that the cleaning effect is not improved, especially when a very small amount of foreign matter or resin components of the previous use remain, such as extrusion sheet molding, even if foreign matter and contamination are clearly recognized, a large amount of cleaning agent If a thermoplastic resin base having a low melt viscosity is used in order to improve the cleaning effect, the resin tends to remain in the molding machine, and the remaining resin causes contamination as a cause.
In particular, it can be used during sheet molding, which was not possible with resins containing abrasives or high-viscosity resins, and it can be used for extrusion molding of engineering plastics such as PET resin, so it does not take a lot of time and effort. In addition, there has been a demand for a method for preventing the occurrence of irregularities and removing foreign matters that cause the irregularities.
JP-A-9-225963 No. 2795451 No. 2774922 JP-A-5-69446 No. 3050774 Japanese Patent Laid-Open No. 10-81898 No. 2501218 No. 2676549

The object of the present invention is to easily replace the resin that is likely to remain in the molding machine with a post-resin and to remove foreign matter. The purging / cleaning effect is high even when a small amount of cleaning agent is used, and the cleaning temperature is high. To provide a cleaning resin composition that can be quickly and quickly replaced with a post-resin by suppressing adhesion to the inner surface of the molding machine and easily discharging the cleaning agent itself from the molding machine. is there.

The inventors of the present invention have completed the present invention as a result of intensive studies to solve such problems. That is, the present invention
(1) (C) Viscosity average with respect to 100 parts by weight of (A) olefin-based thermoplastic resin 20 to 99% by weight and (B) 1 to 80% by weight of unsaturated group-containing carboxylic acid derivative-modified olefin resin An anionic surfactant (0.1 to 100 parts by weight of a polyalkylene oxide or polyalkylene glycol having a molecular weight of 10,000 to 1,500,000, (D) a sulfate or sulfonate having an alkyl group having 8 to 20 carbon atoms) Sulfates or sulfonates selected from K, Na, NH4) and / or metal salts of fatty acids having 6 to 22 carbon atoms (metal salts selected from K, Na, Ca, Mg, Zn) ) In an amount of 0.1 to 10 parts by weight.
(2) (A) The olefin-based thermoplastic resin has a melt flow rate of 0.01 to 60 g / 10 min (190 ° C., 2.16 kg load), and the molding machine cleaning resin according to (1) Composition.
(3) (A) The resin composition for cleaning a molding machine according to (1) or (2), wherein the olefinic thermoplastic resin is polyethylene.
(4) Provided is a molding machine cleaning method in which the resin composition according to (1) to (3) is supplied to a molding machine.

The cleaning resin composition for a molding machine according to the present invention can easily replace a resin that is likely to remain in the molding machine with a post-resin and remove foreign substances. The cleaning effect is high, the adhesion to the inner surface of the molding machine is suppressed at the cleaning temperature, and the cleaning agent itself can be easily discharged from the molding machine, so that the replacement with the post-resin can be performed quickly and rapidly.

The (A) olefinic thermoplastic resin in the present invention typically includes resins such as high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, polybutene, and ethylene-propylene copolymer. In particular, various polyethylenes are preferable because of their excellent cleaning effect. For these polyolefin-based thermoplastic resins, the melt flow rate is 0.01 to 60 g / 10 min (190 ° C., 2.16 kg load), more preferably the melt flow rate is 0.05 to 10 g / 10 min (190 ° C., A high-viscosity thermoplastic resin having a load of 2.16 kg) is preferable.

The (B) unsaturated group-containing carboxylic acid derivative-modified olefin resin in the present invention (hereinafter referred to as a modified olefin resin) is ethylene, propylene, or α, β-unsaturated olefin and α, β-unsaturated. Α, β-unsaturated carboxylic acid derivative or carboxylic acid for copolymer resin made of carboxylic acid derivative or vinyl carboxylate or olefinic (co) polymer made of ethylene, propylene, or α, β-unsaturated olefin It is a graft copolymer resin obtained by grafting vinyl acetate.
Here, the α, β-unsaturated olefin includes 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene and the like.
In addition, α, β-unsaturated carboxylic acid derivatives include α, β-unsaturated carboxylic acid, α, β-unsaturated carboxylic acid anhydride, α, β-unsaturated carboxylic acid ester, or α, β-unsaturated. Specific examples include carboxylic acid amides, and specifically acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, anicotic anhydride, methyl acrylate, Examples include ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, monoethyl maleate, diethyl maleate, acrylic acid dimethylamide, acrylic acid diethylamide, methacrylic acid dimethylamide, and methacrylic acid diethylamide. The above can be used.
Specific examples of vinyl carboxylate include vinyl acetate, vinyl propionate, and vinyl butyrate.
The proportion of α, β-unsaturated carboxylic acid derivative or vinyl carboxylate used is 100 parts by weight of ethylene, propylene, or α, β-unsaturated olefin in total or 100 parts by weight of these olefinic (co) polymers. Is in the range of 0.01 to 60 parts by weight, more preferably 0.1 to 30 parts by weight.
In particular, the production method by graft polymerization of the modified olefin resin is not limited at all. For example, an olefin (co) polymer, an α, β-unsaturated carboxylic acid derivative and a small amount of an organic peroxide are added to a Henschel mixer. The mixed mixture is fed to a single or twin screw extruder and melt kneaded at a temperature of 180 to 250 ° C. The olefinic (co) polymer is dissolved in an appropriate solvent, and α, β -A method of adding an unsaturated carboxylic acid derivative and an organic peroxide and causing a graft reaction in a solution state.

Examples of (C) polyalkylene oxide or polyalkylene glycol used in the present invention include polyethylene oxide, poly (1,2-propylene oxide), poly (1,3-propylene glycol), polytetramethylene glycol, and polyhexamethylene. A block or random copolymer of glycol, ethylene oxide and propylene oxide, a block or random copolymer of ethylene oxide and tetrahydrofuran, or the like is used. Of these, polyethylene oxide is particularly preferable. The amount of polyalkylene oxide or polyalkylene glycol used is 0.1 to 100 parts by weight, preferably 1 to 70 parts by weight, based on 100 parts by weight of (A) olefin-based thermoplastic resin. When the polyalkylene oxide or the polyalkylene glycol is less than 0.1 parts by weight, the foreign matter preventing effect of the resin, which is the object of the present invention, cannot be obtained. On the other hand, when the amount exceeds 100 parts by weight, the polyalkylene oxide or the polyalkylene glycol has a high water absorption rate, which causes a problem in terms of safety and workability. Moreover, the weight average molecular weight of polyalkylene oxide or polyalkylene glycol needs to be 10,000 to 1,500,000. When the weight average molecular weight is less than 10,000, the melt viscosity is remarkably lowered, the resin stays in the extruder, and when the weight average molecular weight exceeds 1,500,000, gelation is caused by heat. The foreign matter prevention effect of the resin which is the object of the invention cannot be obtained.

(D) An anionic surfactant which is a sulfate or sulfonate having an alkyl group having 8 to 20 carbon atoms (sulfate or sulfonate is selected from K, Na and NH4). In general, examples of sulfates include sodium octyl sulfate, sodium ethylhexyl sulfate, sodium undecyl sulfate, sodium dodecyl sulfate, potassium dodecyl sulfate, ammonium dodecyl sulfate, sodium hexadecyl sulfate, and ammonium octadecyl sulfate. it can. The sulfonates include sodium octyl sulfonate, sodium ethyl hexyl sulfonate, sodium undecyl sulfonate, sodium dodecyl sulfonate, potassium dodecyl sulfonate, sodium hexadecyl sulfonate, sodium octadecyl sulfonate, sodium octyl benzene sulfonate. And sodium undecylbenzenesulfonate, sodium dodecylbenzenesulfonate, potassium dodecylbenzenesulfonate, sodium hexadecylbenzenesulfonate, sodium octadecylbenzenesulfonate, and the like. As the anionic surfactant, sulfates or sulfonates can be used alone or in admixture of two or more. Moreover, as a metal salt of a fatty acid having 6 to 22 carbon atoms, magnesium caproate, magnesium caprylate, magnesium caprate, magnesium laurate, magnesium myristate, magnesium palmitate, magnesium stearate, zinc stearate, Examples thereof include sodium stearate, calcium stearate, aluminum stearate, magnesium behenate, magnesium oleate and the like, and these can be used alone or in admixture of two or more. The amount of the anionic surfactant and / or the fatty acid metal salt (D) used is 0.1 to 10 parts by weight per 100 parts by weight of the thermoplastic resin. (D) When a component is less than 0.1 weight part, the foreign material prevention effect becomes low. On the other hand, when the amount exceeds 10 parts by weight, the inside of the extruder and the inside of the molding machine are contaminated, and the effect of preventing foreign matter is lowered, which is not preferable.

Although there is no restriction | limiting in particular in the manufacturing method of the resin composition for washing | cleaning of this invention, (A) Olefin type thermoplastic resin, (B) Modified olefin type resin, (C) Polyalkylene oxide or polyalkylene glycol, (D) An anionic surfactant that is an alkyl group-containing sulfate or a sulfonate and a metal salt of a fatty acid are melt-mixed by a kneader such as a single screw extruder or a twin screw extruder. Further, in the present invention, a foaming agent may be used as necessary. At that time, the foaming agent may be added at the time of kneading and melt-mixed. If it is powder, it can be made into a composition by the method of apply | coating.
Examples of such blowing agents include hydrocarbon compounds such as butane, pentane, hexane, and dimethyl ether, halogenated hydrocarbon compounds such as ethylene dichloride, methylene chloride, and chlorotetrafluoroethane, azodicarbonamide, and azobisisobutyrate. Hydrazine derivatives such as rhonitrile, oxybis (benzenesulfonylhydrazide), trihydrazide triazine, p-toluenesulfonyl semicarbazide, p-toluenesulfonyl azide, dinitrosopentamethylenetetramine, nitrourea, hydrazodicarbonamide, semicarbazide compound, azide compound, Examples thereof include nitroso compounds, triazole compounds, nitro compounds, hydrazo compounds and the like, or two or more organic compound (composite) foaming agents. Examples of the inorganic foaming agent include physically foaming compounds such as water, air, and nitrogen, and ammonium carbonate, sodium bicarbonate, sodium nitrite, sodium borohydride, calcium azide, and the like.

The foreign matter cleaning resin composition of the present invention can be used in known molding machines such as extrusion molding machines and injection molding machines.
Further, as one of the preferred embodiments of the present invention, a small amount of the resin composition for cleaning according to the present invention is supplied to a molding machine to replace it with a post-resin, to clean the molding machine foreign matter, or to prevent foreign matter. Even with the use of this cleaning agent, the purging and cleaning effect is high, and adhesion to the inner surface of the molding machine is suppressed at the cleaning temperature, and the cleaning agent itself can be easily discharged from the molding machine to quickly and quickly replace the resin. Is something that can be done.

〔Example〕
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not restrict | limited at all by these.

[Olefinic thermoplastic resin]
A-1: Linear low density polyethylene Evolue SP3010 manufactured by Mitsui Chemicals, Inc.
A-2: Linear low-density polyethylene Ultzex 2023L manufactured by Mitsui Chemicals, Inc.
A-3: Low density polyethylene Mirason 102 manufactured by Mitsui Chemicals, Inc.
A-4: High density polyethylene Mitsui Chemicals, Inc. Hi-Zex 7000F

[Unsaturated group-containing carboxylic acid derivative-modified olefin resin]
B-1: Ethylene / ethyl acrylate copolymer EVAFLEX-EEA A-710 manufactured by Mitsui DuPont Polychemical Co., Ltd.
B-2: Ethylene / methacrylic acid copolymer Nucleel AN4214C manufactured by Mitsui DuPont Polychemical Co., Ltd.
B-3: Ethylene / vinyl acetate copolymer Everflex EV280 manufactured by Mitsui DuPont Polychemical Co., Ltd.
B-4: Maleic anhydride modified polypropylene Sanyo Chemical Industries, Ltd. Yumex 1010
B-5: Maleic anhydride-modified ethylene / 1-butene copolymer Mitsui Chemicals, Inc. Tafmer MA8510

[Polyalkylene oxide glycol]
C-1: Polyethylene oxide Alcox R-1000 manufactured by Meisei Chemical Co., Ltd.

[Anionic surfactant or fatty acid metal salt]
D-1: Sodium alkyl sulfonate Chemistat 3033 manufactured by Sanyo Chemical Co., Ltd.
D-2: Sodium alkyl sulfate manufactured by Kanto Chemical Co., Inc.

[Production of cleaning resin composition]
Olefin-based thermoplastic resins A-1 to 4, unsaturated group-containing carboxylic acid derivative-modified olefin resins B-1 to 5 and polyethylene oxide C-1, anionic surfactants D-1 to 2, magnesium stearate, organic A foaming agent (azodicarbonamide: “Uniform AZ-H” manufactured by Otsuka Chemical Co., Ltd.) was extruded with the composition shown in Table 1 to obtain cleaning resin compositions E-1 to 10 and e-1 to 5.

[Example 1]
Black material (ethylene-vinyl acetate copolymer, Evaflex EV170 manufactured by Mitsui DuPont Polychemical Co., Ltd.) is used in a 150t injection molding machine (J-150EP manufactured by Nippon Steel), and the back pressure is sufficient. In the state in which the screw is advanced, it is melt-extruded and filled in the molding machine, and then the above-mentioned cleaning agent resin composition E-1 is extruded and the amount of cleaning agent necessary for complete replacement is measured. . The amount is shown in Table 1.
Further, after confirming that the replacement was completed, the back pressure was reduced and the screw was turned back, and the resin in the cylinder was discharged all at once by injection, and the hue of the discharged injection was confirmed. The presence or absence of the discoloration is shown in Table 1.

[Examples 2 to 10]
It implemented similarly to Example 1 except having changed to cleaning agent resin composition E-1 and using E-2-10.

[Comparative Examples 1-5]
It implemented similarly to Example 1 except having changed to cleaning agent resin composition E-1 and using e-1-5.

As is clear from the above results, the cleaning resin composition of the present invention has an excellent resin purging and foreign matter cleaning effect for the molding machine, and can be replaced with a post-resin with a small amount of use. , Its industrial value is high.

Claims (4)

(C) Viscosity average molecular weight 10,000 with respect to 100 parts by weight of a mixture of 20 to 99% by weight of olefinic thermoplastic resin and 1 to 80% by weight of (B) unsaturated group-containing carboxylic acid derivative-modified olefinic resin 0.1 to 100 parts by weight of polyalkylene oxide or polyalkylene glycol of ˜1.5 million, (D) a sulfate having an alkyl group having 8 to 20 carbon atoms, or an anionic surfactant (sulfate, sulfonate) Or a sulfonate salt selected from K, Na, NH4) and / or a metal salt of a fatty acid having 6 to 22 carbon atoms (a metal salt selected from K, Na, Ca, Mg, Zn). 1. A resin composition for cleaning a molding machine, containing 1 to 10 parts by weight. (A) The olefin-based thermoplastic resin has a melt flow rate of 0.01 to 60 g / 10 min (190 ° C., 2.16 kg load). (A) The resin composition for cleaning a molding machine according to claim 1 or 2, wherein the olefinic thermoplastic resin is polyethylene. A cleaning method for a molding machine, wherein the resin composition according to claim 1 is supplied to the molding machine.