JP3552091B2 - Cleaning agent for molding machines - Google Patents

Description

表１中の数字は全て重量部である。なお、（）内の数値はポリエチレンのＭＩ値である。
【００２４】
以上の結果から明らかなように、実施例１〜３に係る成形機用洗浄剤は、洗浄性と焼け・目やにの発生防止効果共に、優秀である。これに対して、無硫黄ファクチスを１．０重量部以上含有させた比較例１及び３〜５に係る成形機用洗浄剤の場合、焼け・目やにの発生防止効果が低下する。また、無硫黄ファクチスを０．５重量部含有させた比較例２に係る成形機用洗浄剤の場合、焼け・目やにの発生防止効果は優秀であるが、熱可塑性樹脂としてＭＩ値１．００のポリエチレンを使用したので、洗浄性が若干低下する。
【００２５】
【発明の効果】
以上説明したように、本発明に係る成形機用洗浄剤を用いて成形機を洗浄すると、ＭＩ値０．１以下の熱可塑性樹脂と、比較的少量のファクチスと、ＭＩ値０．１以下の熱可塑性樹脂の酸化を防止するための酸化防止剤との共働作用で、洗浄性に優れ、且つ焼け・目やにが発生しにくいという効果を奏する。従って、本発明に係る成形機用洗浄剤を用いれば、一台の成形機で、効率良く品種変えを行うことができ、プラスチック成形加工分野において、格別に有益なものである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a detergent for molding machines such as an extrusion molding machine and an injection molding machine. The extruder is a type of extruder, and is included in the extruder according to the present invention.
[0002]
[Prior art]
Molding machines are widely used for molding thermoplastic resins. A molding machine is generally provided with a screw therein, the molten or extruded thermoplastic resin is extruded forward by this screw, and the thermoplastic resin is molded into a predetermined shape through a die or a nozzle. is there. Since such a molding machine produces various molded products by one machine, when changing the product type, the inside of the molding machine is washed and residual resin and pigment etc. of the pre-molded product adhered to a screw, a die and the like are removed. Need to be removed. Various cleaning agents have been proposed as a cleaning agent for removing the residual resin and the like.
[0003]
For example, Japanese Patent Publication No. 6-78557 proposes a detergent comprising a thermoplastic resin, factice, a lubricant and a nonionic surfactant. This is because the factice mainly scrapes or adsorbs the residual resin or the like adhering to the surface of the screw or the like, thereby exhibiting a cleaning effect. Therefore, it is essential that factice be contained in an amount of 1 to 30 parts by weight based on 100 parts by weight of the thermoplastic resin. However, when the amount of factice is at this level, carbide (factice residue) adheres to the screw after washing (such a phenomenon is called “burning”), or the exit of a die or nozzle. There is a case where carbide or the like adheres to the surface (such a phenomenon is referred to as "eyes and eyes").
[0004]
[Problems to be solved by the invention]
In order to prevent the "burn" and "eyeburn", it is only necessary to reduce the amount of factice. However, if the amount of factice is reduced, the cleaning effect is naturally insufficient. Therefore, as a result of various studies conducted by the present inventors, the use of a thermoplastic resin having a specific MI value, and the addition of an antioxidant to prevent oxidation of the thermoplastic resin, the factice It has been found that even if the amount is reduced, a decrease in the cleaning effect can be prevented. The present invention has been made based on such findings.
[0005]
[Means for Solving the Problems]
That is, the present invention contains a thermoplastic resin having an MI value of 0.1 or less, a factice, and an antioxidant, and the factice is present in an amount of 0.05 to 0.9 with respect to 100 parts by weight of the thermoplastic resin. The present invention relates to a cleaning agent for a molding machine, characterized by being contained in parts by weight.
[0006]
Examples of the thermoplastic resin used in the present invention include polyethylene, polypropylene, polystyrene, polyester, and polyamide. Among them, it is particularly preferable to use polyethylene. The MI value of this thermoplastic resin is 0.1 or less. If the MI value exceeds 0.1, the cleaning effect is reduced, which is not preferable. Here, the MI value is measured by the method described in JIS K 7210, and indicates the degree of fluidity of the thermoplastic resin. The higher the MI value, the better the fluidity. In the present invention, a cleaning effect is exerted by synergistic action between a thermoplastic resin having an extremely low fluidity having an MI value of 0.1 or less and factice.
[0007]
As the factice used in the present invention, any conventionally known factice is used. Specifically, sulfur factices such as sulfur vulcanizates of hydrogenated rapeseed oil and sulfur vulcanizates of vegetable oils, sulfur factices such as sulfur vulcanizates of refined rapeseed oils, vegetable oils and modified alkyds, and peroxides and isocyanates. Sulfur-free factice or the like can be used. Among these, it is particularly preferable to use sulfur-free factice. The amount of the factice is 0.05 to 0.9 parts by weight, particularly preferably 0.4 to 0.6 parts by weight, based on 100 parts by weight of the thermoplastic resin. If the amount of factice is less than 0.05 part by weight, the cleaning effect is reduced, which is not preferable. On the other hand, if the amount of the factice exceeds 0.9 parts by weight, "burn" and "eyeburn" occur after washing, which is not preferable.
[0008]
The antioxidant used in the present invention is for preventing oxidation of a thermoplastic resin or factice. That is, many thermoplastic resins and factices having an MI value of 0.1 or less have good cleaning action but are easily oxidized by heating. Therefore, in order to prevent this oxidation, an antioxidant is blended in the present invention. As the antioxidant, any conventionally known one can be used, and particularly, a phenol-based or amine-based one is used. Specifically, 2,6-ditert-butyl-4-methylphenol, n-octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate and the like are used. The compounding amount of the antioxidant is preferably about 0.1 to 1.0 part by weight. If the amount of the antioxidant is less than 0.1 part by weight, the antioxidant tends to be insufficient. If the amount exceeds 1.0 part by weight, the effect is not so much improved.
[0009]
In the present invention, it is also preferable that an ionic surfactant is further contained. Examples of the ionic surfactant include an anionic surfactant, a cationic surfactant, and an amphoteric surfactant. This is because these ionic surfactants enhance the cleaning effect in cooperation with a thermoplastic resin having MI value of 0.1 or less and factice. The compounding amount of the ionic surfactant may be about 0.1 to 3.0 parts by weight. If the amount of the ionic surfactant is less than 0.1 part by weight, the improvement of the cleaning effect tends to be small. If the amount exceeds 3.0 parts by weight, the cleaning effect is not so much improved.
[0010]
Furthermore, in the present invention, it is also preferable to contain inorganic fine particles or inorganic fibers. This is because the inorganic fine particles or the inorganic fibers are excellent in performance of removing "burn" attached to the screw or the like. As the inorganic fine particles, fine particles of glass, talc, calcium carbonate, wollastonite and the like are used. The particle size of the inorganic fine particles is arbitrary, but generally may be about 5 to 100 μm. Glass fibers, carbon fibers, and the like are used as the inorganic fibers. The diameter and fiber length of the inorganic fiber are also arbitrary, but generally the diameter is 5 to 100 μm and the fiber length is about 1 to 10 mm. The compounding amount of the inorganic fine particles or the inorganic fibers is preferably about 10 to 40 parts by weight based on 100 parts by weight of the thermoplastic resin. If the compounding amount of the inorganic fine particles or the inorganic fibers is less than 10 parts by weight, there is a tendency that the performance of removing "burn" attached to a screw or the like becomes insufficient. Further, even when the amount exceeds 40 parts by weight, the performance of removing "burn" attached to the screw or the like does not improve much.
[0011]
Furthermore, in the present invention, it is preferable that a fragrance is contained. This is because if a fragrance is contained, an unpleasant odor generated during washing can be prevented. As the fragrance, a conventionally known natural fragrance or synthetic fragrance is used. In particular, it is preferable to use a mint flavor, a citrus flavor, a lavender flavor, etc. as the flavor. The amount of the fragrance may be about 0.01 to 1 part by weight based on 100 parts by weight of the thermoplastic resin.
[0012]
Furthermore, in the present invention, it is also preferable to include a melt conditioner containing a plasticizer and / or an organic peroxide. As the plasticizer, a phthalate ester-based plasticizer is preferable, for example, dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl phthalate, diheptyl phthalate, di-n-octyl phthalate, di-2-phthalate. Ethylhexyl, diisooctyl phthalate, di-n-octyl phthalate, dinolyl phthalate, diisodecyl phthalate, ditridecyl phthalate, dicyclohexyl phthalate, butyl benzyl phthalate, butyl lauryl phthalate, methyl oleyl phthalate and the like can be used. . Among these, dimethyl phthalate or dibutyl phthalate is preferred. Examples of the organic peroxide include t-butyl hydroperoxide, 1,3-bis (t-butylperoxyisopropyl) benzene, benzoyl peroxide, methyl isobutyl ketone peroxide, t-butyl perbenzoate, and diisopropylperoxy. Dicarbonate, vinyl tris (t-butylperoxy) silane, or the like can be used. All of these are intended to improve the cleaning ability or to reduce the residual cleaning agent in the molding machine by adjusting the fluidity of the thermoplastic resin in the cleaning agent. The blending amount of the melt modifier may be about 0.01 to 1 part by weight based on 100 parts by weight of the thermoplastic resin. If the blending amount of the melt modifier is less than 0.01 part by weight, there is a tendency that the fluidity cannot be adjusted. If the amount exceeds 1 part by weight, the fluidity of the detergent tends to be extremely reduced.
[0013]
The detergent for a molding machine according to the present invention as described above comprises a thermoplastic resin having an MI value of 0.1 or less, a factice, an antioxidant, and, if necessary, an ionic surfactant and / or inorganic fine particles or inorganic fibers. And / or a perfume and / or a melt modifier can be obtained by mixing with a tumbler or a high-speed mixer and kneading with an extruder. The detergent for a molding machine is provided in an arbitrary form, for example, in a powder form, a pellet form, a flake form, or the like. Then, after the molded product is obtained by the molding machine, the residual resin and the like in the molding machine are washed and removed by passing a cleaning agent through the molding machine before changing to a different type from the molded product. .
[0014]
【Example】
Example 1
100 parts by weight of polyethylene having an MI value of 0.05, 0.5 part by weight of sulfur-free factice (manufactured by Tenma Sub Processing Co., Ltd., U-8), and an antioxidant (Sumilyzer BHT, manufactured by Sumitomo Chemical Co., Ltd.) After uniformly mixing with 2 parts by weight, the mixture was pelletized with an extruder to obtain a detergent for a molding machine.
[0015]
Example 2
A cleaning agent for a molding machine was obtained in the same manner as in Example 1, except that 1.0 part by weight of an anionic surfactant (Denone 1886, manufactured by Marubishi Yuka Kogyo Co., Ltd.) was further added.
[0016]
Example 3
A cleaning agent for a molding machine was obtained in the same manner as in Example 2, except that 0.1 part by weight of an organic peroxide (POX-1 manufactured by NOF CORPORATION) was further added.
[0017]
Comparative Example 1
A cleaning agent for a molding machine was obtained in the same manner as in Example 1, except that the amount of the sulfur-free factice was changed to 1.0 part by weight.
[0018]
Comparative Example 2
A cleaning agent for a molding machine was obtained in the same manner as in Example 1, except that polyethylene having an MI value of 1.00 was used instead of polyethylene having an MI value of 0.05.
[0019]
Comparative Example 3
A detergent for a molding machine was obtained in the same manner as in Comparative Example 2, except that the amount of the sulfur-free factice was changed to 1.0 part by weight.
[0020]
Comparative Example 4
A cleaning agent for a molding machine was obtained in the same manner as in Comparative Example 2, except that the amount of sulfur-free factice was changed to 2.0 parts by weight.
[0021]
Comparative Example 5
A molding machine detergent was obtained in the same manner as in Comparative Example 4, except that no antioxidant was added.
[0022]
300 g of the cleaning agent for each molding machine according to Examples 1 to 3 and Comparative Examples 1 to 5 was passed while melting at a temperature of 250 ° C. through the molding machine to which the residual resin and the like were adhered. Washed. Then, after the completion of the washing, the washing property and the scorch / burn were evaluated by the following methods. The results are shown in Table 1.
[Washability]: By visually observing the inside of the molding machine, the degree of removal of residual resin and the like was evaluated in the following four steps.・ ・ ・: Residual resin and the like were almost completely removed.・ ・ ・: Residual resin and the like were generally removed, but partly remained. Δ: Residual resin and the like were partially removed. ×: Residual resin and the like were hardly removed.
[Burning / eyeburn]: Visual observation of whether or not burns have occurred on the screw part and the inner wall of the molding machine and whether or not eyes have occurred on the exit of the die of the molding machine. evaluated.・ ・ ・: Almost no burning or eyes occurred. ○: Burns and eyes were almost not generated, but some burns and eyes were observed. Δ: Burns / eye spots occurred in some places. C: Burns and eyes are noticeable.
[0023]
[Table 1]

All numbers in Table 1 are parts by weight. The numerical values in parentheses are the MI values of polyethylene.
[0024]
As is clear from the above results, the detergents for molding machines according to Examples 1 to 3 are excellent in both the detergency and the effect of preventing the occurrence of burns and burns. On the other hand, in the case of the cleaning agents for molding machines according to Comparative Examples 1 and 3 to 5 containing at least 1.0 part by weight of sulfur-free factice, the effect of preventing burning and burning is reduced. Further, in the case of the detergent for a molding machine according to Comparative Example 2 containing 0.5 parts by weight of sulfur-free factice, the effect of preventing burning and fogging is excellent, but the MI value of the thermoplastic resin is 1.00. Since polyethylene is used, detergency is slightly reduced.
[0025]
【The invention's effect】
As described above, when the molding machine is cleaned using the cleaning agent for a molding machine according to the present invention, a thermoplastic resin having an MI value of 0.1 or less, a relatively small amount of factice, and an MI value of 0.1 or less are used. By synergistic action with an antioxidant for preventing oxidation of the thermoplastic resin, it has an effect of being excellent in detergency and less likely to cause burning and eyes. Therefore, if the cleaning agent for a molding machine according to the present invention is used, the type can be changed efficiently with one molding machine, which is particularly useful in the plastic molding and processing field.

Claims (5)

It contains a thermoplastic resin having an MI value of 0.1 or less, factice, and an antioxidant, and the factice is contained in an amount of 0.05 to 0.9 parts by weight based on 100 parts by weight of the thermoplastic resin. A cleaning agent for molding machines. The cleaning agent for a molding machine according to claim 1, further comprising an ionic surfactant. The cleaning agent for a molding machine according to claim 1 or 2, further comprising inorganic fine particles or inorganic fibers. The cleaning agent for a molding machine according to any one of claims 1 to 3, further comprising a fragrance. The cleaning agent for a molding machine according to any one of claims 1 to 4, further comprising a melt conditioner containing a plasticizer and / or an organic peroxide.