JP3050774B2 - Cleaning material and cleaning method for heating tower in resin molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning material for a heating tower in a resin molding machine containing a thermoplastic resin and a foaming agent, and a cleaning method. More specifically, the cleaning material can be suitably used for cleaning the inside of a heating tower such as an extrusion molding machine or an injection molding machine, or a screw or a cylinder (barrel).

[0002]

2. Description of the Related Art Conventionally, in the molding of thermoplastic resins, for example, extrusion molding, injection molding and the like, various resins and coloring agents are used according to demand, but subsequently, other resins and coloring agents are used. When molding, the resin used before that (hereinafter also referred to as the preceding resin) and the colorant remain in the heating tower of the molding machine, so that they are removed, that is, without disassembling the heating tower of the molding machine. It is necessary to clean the inside.

[0003] For this purpose, for example, a material of the same or different quality as the material to be subsequently molded or a material containing glass fibers is supplied to a molding machine under the same conditions as in the molding, for example. Cleaning is performed in which the residue is scraped off by the polishing action and then extruded by the extruding action of the resin.

However, in recent years, thermoplastic resin compositions containing various flame retardants have been marketed for the purpose of improving the flame retardancy of thermoplastic resins. For cleaning the inside of the heating tower, the desired effect cannot be obtained only by the cleaning by the extrusion action or the polishing action as described above.

As the flame retardant, for example, a large number of compounds such as an organic halogenated compound, a phosphoric ester compound, and an antimony compound are used. Since the flame retardant is thermally decomposed in a tower portion or the like to generate, for example, an acidic substance or an oxidizing substance, iron used as a material inside the heating tower or the like is corroded.

[0006] In addition to the flame retardant, the thermoplastic resin composition may contain, if necessary, a stabilizer, a lubricant, a plasticizer, an ultraviolet absorber, an antioxidant, an antistatic agent, a pigment, a dye, and the like. Various additives are blended, from which various acidic substances and oxidizing substances are generated by thermal decomposition,
This is the cause of the corrosion.

[0007] Of course, the thermoplastic resin, which accounts for the majority of the composition, also undergoes thermal decomposition, causing the corrosion.

[0008] Further, carbides and the like generated by the above-described thermal decomposition remain without being washed, or additives contained in the thermoplastic resin, such as pigments and dyes, remain. Then, these are mixed into the molding material newly supplied into the heating tower of the molding machine, so that there is a problem of molding defects such as defective color mixing of the obtained molded products and defective foreign materials.

In order to solve these problems, for example, a thermoplastic resin and a metal soap such as zinc stearate,
Phosphates such as sodium phosphate and sodium tripolyphosphate,
A cleaning material (a so-called purge material) comprising a silicate such as sodium metasilicate, glass fiber, or the like is commercially available, but at present it has not yet been able to solve the above-mentioned problems.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide additives (mainly pigments, mainly pigments, etc.) contained in a preceding resin remaining in a heating tower of a resin molding machine, screws, cylinders (barrels) and the like. To provide a cleaning material for a heating tower in a resin molding machine and a cleaning method capable of efficiently removing residues generated by heat molding of the preceding resin, acidic substances, oxidizing substances, carbides and the like. .

[0011]

The present invention comprises 100 parts by weight of a thermoplastic resin and 0.001 to 50 parts by weight of a foaming agent.
The thermoplastic resin is incompatible with the preceding resin and the incompatible resin.
The present invention relates to a cleaning material for a heating tower in a resin molding machine , which is a mixture of soluble resins .

Further, the present invention provides a method for heating a resin molding machine heating tower, wherein the cleaning material is supplied to the molding machine heating tower, and then the cleaning material is physically and / or chemically foamed in the molding machine heating tower. The present invention relates to a method for cleaning the inside of a molding machine heating tower.

[0013]

Operation and Examples Although it is not clear why the cleaning material for a resin molding machine heating tower of the present invention exhibits an excellent cleaning effect, the following may be considered, for example.

When the cleaning material is heated in a heating tower of a molding machine or the like, the foaming agent is thermally decomposed to generate, for example, nitrogen gas, carbon monoxide gas, ammonia gas, formaldehyde gas, water vapor, carbon dioxide and the like. I do.

The thermoplastic resin in the cleaning material foams and expands due to the pressure of these gases, and adheres to, for example, a residue in the inside of the heating tower or takes in the resin. It is conceivable to physically extrude and remove the remaining carbide, for example.

On the other hand, since the carbon monoxide and formaldehyde have a reducing property, for example, the oxidizing substance generated by the decomposition of the flame retardant or the like is reduced to lose its oxidizing power, so that it remains. It is conceivable to chemically remove oxidizing substances and prevent corrosion of iron, which is a material of the molding machine.

Further, since the ammonia has a neutralizing action, for example, it neutralizes acidic substances generated by the decomposition of the flame retardant or the like, so that the remaining acidic substances are chemically removed. At the same time, it is conceivable to prevent the corrosion of iron as described above.

Some of the foaming agents, such as sodium bicarbonate, contain an alkaline substance in the residue after being decomposed to generate gas, and this has a neutralizing effect.

Some of the foaming agents contain a reducing substance in the residue after being decomposed to generate gas, and this has a reducing action.

The foaming agent used in the present invention may be any one commercially available as an organic or inorganic foaming agent. In addition to those commercially available as organic or inorganic foaming agents, for example, It is also conceivable to use water, ammonium carbonate, sodium hydrogen carbonate and the like. Actually, any foam may be used as long as the foam is generated by physical or chemical change in the heating tower of the molding machine, and the cleaning effect is enhanced by the foaming power. Some inorganic foaming agents generate an alkaline substance or a reducing substance.

Examples of the organic foaming agent include organic physical foaming agents such as aliphatic hydrocarbons such as pentane and hexane, chlorinated hydrocarbons such as dichloroethane and methylene chloride, and fluorinated chlorohydrocarbons such as chlorofluorocarbon. , Azodicarbonamide (ADCA), azobisisobutyronitrile (AIBN), barium azodicarboxylate, hydrazine derivatives such as diazoaminobenzene, p, p'-oxybis (benzenesulfonyl hydrazide) (OBSH), paratoluene Sulfonyl hydrazide (TSH), acetone-p-toluenesulfonyl hydrazone, 2,4-toluenedisulfonyl hydrazide, p-methylurethanebenzenesulfonyl hydrazide, oxalyl hydrazide, trihydrazinotriazine (triaminomelamine Semicarbazide compounds such as (THT), azides such as p-toluenesulfonyl semicarbazide, nitroso compounds such as p-toluenesulfonylazide, N, N'-dimethyl-N, N'-dinitrosoterephthalamide, dinitrosopentamethylenetetramine Organic chemical blowing agents such as (DPT), triazole compounds such as trinitrosotrimethylenetriamine, nitro compounds such as nitrourea and nitroguanidine, and hydrazo compounds such as hydrazodicarbonamide (HDCA).

Among these organic chemical blowing agents, ADC
A, trihydrazinotriazine, and the like also have a function of neutralizing acids because the decomposition gas contains alkaline ammonia. In addition, since the decomposition gas of DPT contains formaldehyde, it has a reducing property and ADC
Since the decomposition gas of A contains carbon monoxide, it also has a reducing property.

In addition, microballoons in which low-boiling compounds such as the above-mentioned aliphatic hydrocarbons are included in microcapsules are also examples of organic physical foaming agents.

Further, the reaction with water generates carbon dioxide gas, and is mainly used for urethane foaming, for example, tolylene diisocyanate, isophorone diisocyanate,
Isocyanate compounds such as diphenylmethane diisocyanate are also examples of organic chemical blowing agents.

Among the above-mentioned organic foaming agents, the gas generated by foaming has low toxicity, is inexpensive, has a high foaming power (pressure), and has an alkaline property as a neutralizing agent for acidic substances in the generated gas. ADCA, DP from the viewpoints that substances as substances and oxidizing substances as a reducing agent are generated, decomposition residues are small, and decomposition products do not corrode iron.
T, HDCA, barium azodicarboxylate and trihydrazinotriazine are preferred, and ADCA and DPT are more preferred.

Examples of the inorganic foaming agent include water,
Inorganic physical blowing agents such as nitrogen and air, hydrogen carbonates such as sodium hydrogen carbonate and ammonium hydrogen carbonate, carbonates such as sodium carbonate and ammonium carbonate, nitrites such as ammonium nitrite, and hydrides such as sodium borohydride , Calcium azide and other azide compounds, light metals such as magnesium and aluminum, sodium bicarbonate and acid, hydrogen peroxide and yeast, and aluminum powder and acid. Can be

Among these inorganic chemical blowing agents, the decomposition gas of ammonium carbonate, ammonium bicarbonate, and ammonium nitrite contains ammonia, which has the effect of neutralizing acids and sodium bicarbonate has the effect of neutralizing acids. Since sodium carbonate itself is an alkaline substance and sodium carbonate generated by decomposition is also an alkaline substance, each of them has an action of neutralizing an acid. Further, ammonium nitrite has a reducing property of a nitrite group.

Among the inorganic foaming agents, the gas generated by foaming has low toxicity, is inexpensive and economical, is easy to handle, has a high foaming force (pressure), and has a low Contains alkaline substances as neutralizing agents for acidic substances and substances as reducing agents for oxidizing substances, does not corrode iron, and contains residues of alkaline substances and reducing substances after decomposition. Sodium bicarbonate, ammonium bicarbonate, ammonium carbonate and ammonium nitrite are preferred from the point of view that they are alkaline substances and their decomposition products are also alkaline substances. Ammonium nitrite in which the product contains an alkaline substance is more preferred.

The thermoplastic resin used in the cleaning material of the present invention generally includes a resin which is well compatible with the preceding resin and additives such as dyes, pigments or carbides which are foreign substances, and the above-mentioned dyes and pigments. Alternatively, a resin that is compatible with the carbide but not compatible with the preceding resin is also included.

In practice, it is sometimes necessary to use a thermoplastic resin which may or may not be compatible with the preceding resin. It is used properly depending on the state of contamination inside the heating tower of the molding machine.

However, the important points of the thermoplastic resin used here are: 1) inexpensiveness; 2) well compatible with the preceding resin, pigment, dye or carbide;
Or have the effect of adsorbing them and pushing out the dirt in the heating tower to the outside of the heating tower. 3) It is not compatible with the preceding resin, pigment, dye or carbide, but adsorbs them and removes the dirt in the heating tower. 4) The resin has a function to extrude outside the heating tower. 4) It is a resin that does not easily adhere to the surface of the screw and cylinder (barrel) in the molding machine heating tower. 5) The screw and cylinder (barrel) in the molding machine heating tower. Does not corrode iron. 6) Does not easily remain in the heating tower of the molding machine. (Polyvinyl chloride and the like decompose to generate chlorine gas and cannot be used because it corrodes the iron.) 7) Non-toxic and non-reactive 8) Consider the global environment, such as biodegradable thermoplastic resin synthesized from starch such as corn starch. (Lumps of cleaning material used for cleaning operations must be soild for disposal purposes.) When filling in, etc. It prevent environmental pollution) it is requested by biodegradation.

From the above, for example, ABS is used as the preceding resin.
When using, ABS, as a compatible resin,
AS, PC, PMMA (acrylic resin) and the like, and incompatible resins such as HDPE, LDPE, PP,
GPPS (General Purpose Polystyrene), HIP
S (high impact polystyrene) and the like.

Table 1 shows the compatibility of the preceding resin with the thermoplastic resin used for the cleaning material of the present invention.

In Table 1, ○ indicates that the compatibility is good, Δ indicates that the compatibility is poor, and x indicates that there is no compatibility.

In Table 1, abbreviations as types of resins indicate the following resins.

ABS: acrylonitrile-butadiene-
Styrene copolymer ASA: acrylonitrile-acrylic rubber-styrene copolymer CA: cellulose acetate resin EVA: ethylene-vinyl acetate copolymer PA6: nylon 6 PA6-6: nylon 6-6 PC: polycarbonate HDPE: high-density polyethylene LDPE: Low density polyethylene PMMA: Polymethyl methacrylate (acrylic resin) POM: Polyoxymethylene PP: Polypropylene Modified PPO (E): Modified polyphenylene oxide (ether) GPPS: General purpose polystyrene HIPS: High impact polystyrene PBT: Polybutylene terephthalate TPU: thermoplastic polyurethane PVC: polyvinyl chloride SAN: styrene-acrylonitrile copolymer resin PET: polyethylene terephthalate PVAC: PO Vinyl acetate PPS: Polyphenylene sulfide Blend PC / PBT: polycarbonate and polybutylene terephthalate and the polymer blend Blend PC / ABS: polycarbonate and acrylonitrile - butadiene - polymer blends with styrene copolymer

[0037]

[Table 1]

In the present invention, if necessary, additives such as inorganic fibers, inorganic powders, organic fibers, organic powders, metal fibers, metal powders, alkaline substances, reducing agents, cleaning aids and the like may be appropriately used. it can.

The inorganic fibers have the function of physically and mechanically removing foreign substances such as carbides, rust, and residues of the preceding resin (eg, pigments and dyes) attached to the inside of a heating tower of a molding machine. Specific examples thereof include glass fiber, potassium titanate fiber, carbon fiber, rock wool, asbestos, and the like, and glass fiber is preferable in terms of low cost and non-toxicity.

The inorganic powder has the function of physically and mechanically removing foreign substances such as carbides, rust, and residues of the preceding resin (eg, pigments and dyes) attached to the inside of a heating tower of a molding machine. Specific examples thereof include, for example, alumina, magnesia, glass beads, corundum,
Examples include carborundum, mica, stone powder, glass chips, sodium hydroxide, sodium bicarbonate, sodium carbonate, calcium hydroxide, calcium oxide, zinc oxide, sodium oxide, etc. Mica, glass chips, and glass beads are preferred in that they do not easily damage the barrel.

The organic fibers have the function of physically and mechanically removing foreign substances such as carbides, rust, and residues of the preceding resin (eg, pigments and dyes) attached to the inside of a heating tower of a molding machine. Specific examples thereof include, for example, nylon fiber, polyester fiber, cellulose fiber,
Wool and the like can be mentioned, but cellulose fibers are preferred in that they are inexpensive and are not melted by heat in the heating tower.

The organic powder has an action of physically and mechanically removing foreign substances such as carbides, rust, and residues (eg, pigments and dyes) of the preceding resin adhered to the inside of a heating tower of a molding machine. Specific examples thereof include sawdust, paper powder, and cellulose powder. Of these, sawdust and paper powder are preferred from the viewpoint of low cost and inability to dissolve due to heat in the heating tower.

The metal fibers have the function of physically and mechanically removing foreign substances such as carbides, rust, and residues of the preceding resin (eg, pigments and dyes) attached to the inside of the heating tower of the molding machine. Specific examples thereof include, for example, steel fiber, copper fiber, aluminum fiber, magnesium fiber, zinc fiber, nickel fiber, chromium fiber, manganese fiber, stainless steel fiber as a titanium fiber or an alloy thereof, brass fiber, and the like. Copper fiber, steel fiber, stainless steel fiber or brass fiber as an alloy of these materials because they are inexpensive, hard to damage the screw and cylinder (barrel) of the heating tower, and safe (fire) Is preferred.

The metal powder has the function of physically and mechanically removing foreign substances such as carbides, rust, and residues of the preceding resin (eg, pigments and dyes) attached to the inside of a heating tower of a molding machine. Specific examples thereof include, for example, iron powder, copper powder, aluminum powder, magnesium powder, nickel powder, chromium powder, manganese powder, and stainless steel powder and brass powder as their alloys. In addition, iron powder, copper powder, zinc powder, or stainless steel powder or brass powder as an alloy of these are preferable because they are hard to damage the screw and cylinder (barrel) of the heating tower and are safe (fire). .

Among these metal powders, for example, magnesium, aluminum, and alloys thereof are reductive because they react with water to generate hydrogen gas. In addition, magnesium and aluminum are metals that are more noble than iron (the material of the screw and cylinder (barrel) of the molding machine heating tower), so if iron and magnesium or aluminum coexist, magnesium or aluminum corrodes. , Iron is corrosion protected. Such a function is called a sacrificial anode. The oxidation reaction of the metal takes place at the anode and the reduction reaction takes place at the cathode. As a result, magnesium or aluminum acts as a reducing agent for iron and has reducing properties.

The alkaline substance has a function of neutralizing an acidic substance generated by thermal decomposition in the heating tower, and specific examples thereof include sodium hydroxide, sodium hydrogen carbonate, sodium carbonate, and the like. Calcium hydroxide, calcium oxide, zinc oxide, in addition to those mentioned as the inorganic powder such as sodium oxide, monoethanolamine, triethanolamine, amines such as aniline and salts thereof,
Calcium oxide, zinc oxide, sodium hydrogen carbonate, and sodium carbonate are preferred from the viewpoints of being inexpensive, easy to handle, less irritating to the human body, and safe.

The reducing agent has a function of reducing an oxidizing substance generated in the decomposition of the flame retardant, and specific examples thereof include thiosulfates such as sodium thiosulfate, sodium nitrite, and ammonium nitrite. And nitrites such as potassium nitrite, inorganic reducing agents such as oxygen scavengers such as reduced iron (ageless), organic reducing agents such as formaldehyde, oxalate, hydrazine and its derivatives, and hydroquinone. Nitrite, thiosulfate, or formaldehyde generated by decomposition of solids (generated by decomposition of DPT) is preferable from the viewpoints of low cost, easy handling of solids, and the like.

The cleaning aid has a function of further improving the cleaning effect of the additive, and also has a function of removing (cleaning) carbides and the like present in the heating tower. Specific examples include wax components such as stearic acid, sodium stearate,
Examples include metal soaps such as zinc stearate, phosphates such as sodium phosphate and sodium tripolyphosphate, and silicates such as sodium metasilicate, which are inexpensive, have a high cleaning effect, and prevent corrosion of metals. Thus, a mixture of zinc stearate and sodium tripolyphosphate is preferred.

The mixing ratio of the thermoplastic resin and the foaming agent is, for example, 100 parts of the thermoplastic resin (parts by weight,
The same applies hereinafter) to the foaming agent in an amount of 0.001 to 50 parts,
The amount is preferably from 0.1 to 10 parts, more preferably from 0.5 to 5 parts. When the amount of the foaming agent is less than 0.001 part, the cleaning effect by the foaming force (pressure) cannot be increased. If the amount exceeds 50 parts, the foaming power is too strong and there is a danger (there is a danger of burns due to scattering of the molten resin during purging).

When the inorganic fibers are used, the mixing ratio of the thermoplastic resin and the inorganic fibers is, for example, 50 parts or less of the inorganic fibers with respect to 100 parts of the thermoplastic resin.
It is preferably from 15 to 50 parts, more preferably from 20 to 40 parts. When the amount of inorganic fiber is reduced, a sufficient washing effect and an effect of removing dirt in the heating tower (polishing effect) tend to be hardly obtained. Yes, a sufficient amount tends to provide a sufficient cleaning effect, but an amount exceeding 50 parts is not economical.

When the inorganic powder is used, the mixing ratio of the thermoplastic resin and the inorganic powder is, for example, 50 parts or less of the inorganic powder with respect to 100 parts of the thermoplastic resin.
The amount is preferably 5 to 50 parts, more preferably 20 to 40 parts. When the amount of the inorganic powder is small, a sufficient cleaning effect and a polishing effect tend to be hardly obtained, and when the amount is large, a sufficient cleaning effect is more obtained. However, if it exceeds 50 parts, it is not economical.

When the organic fibers are used, the mixing ratio of the thermoplastic resin and the organic fibers is, for example, 50 parts or less of the organic fibers with respect to 100 parts of the thermoplastic resin.
The amount is preferably from 5 to 50 parts, more preferably from 20 to 40 parts. When the amount of the organic fibers decreases, the cleaning effect and the polishing effect tend to decrease, and when the amount increases, the sufficient cleaning effect is more easily obtained. There is a tendency, but if it exceeds 50 parts, it is not economical.

When the organic powder is used, the mixing ratio of the thermoplastic resin and the organic powder is, for example, 50 parts or less of the organic powder with respect to 100 parts of the thermoplastic resin.
The amount is preferably 5 to 50 parts, more preferably 20 to 40 parts. When the amount of the organic powder is small, a sufficient cleaning effect and a polishing effect tend to be hardly obtained, and when the amount is large, a sufficient cleaning effect is more obtained. However, if it exceeds 50 parts, it is not economical.

When the metal fiber is used, the mixing ratio of the thermoplastic resin and the metal fiber is, for example, 25 parts or less of the metal fiber with respect to 100 parts of the thermoplastic resin.
The amount is preferably from 10 to 25 parts, more preferably from 15 to 25 parts. When the amount of metal fibers is small, sufficient cleaning and polishing effects tend to be hardly obtained, and when the amount is large, sufficient cleaning and polishing effects are obtained. However, it is not economical to use more than 25 parts.

When the metal powder is used, the mixing ratio of the thermoplastic resin and the metal powder is, for example, 25 parts or less of the metal powder with respect to 100 parts of the thermoplastic resin.
The amount is preferably from 10 to 25 parts, more preferably from 15 to 25 parts. When the amount of the metal powder is small, a sufficient cleaning effect and a polishing effect tend to be hardly obtained. However, it is not economical to use more than 25 parts.

When the alkaline substance is used, the mixing ratio of the thermoplastic resin and the alkaline substance is as follows:
For example, alkali is 30 parts or less, preferably 0.1 to 20 parts, and more preferably 100 parts of thermoplastic resin.
The content is more preferably from 10 to 10 parts, and when the amount of the alkaline substance is reduced, the acidic substance in the molding machine heating tower tends to be hardly neutralized, and when the amount is increased, the remaining acidic substance tends to be easily neutralized. However, if it exceeds 30 parts, it is not economical.

When the reducing agent is used, the mixing ratio of the thermoplastic resin and the reducing agent is, for example, 30 parts or less of the reducing agent with respect to 100 parts of the thermoplastic resin.
The amount is preferably 0 part, more preferably 0.1 to 10 parts, and when the reducing agent decreases, the oxidizing substance in the molding machine heating tower tends to be difficult to be reduced. Oxidizing substances tend to be easily reduced, but if it exceeds 30 parts, it is not economical.

When the cleaning aid is used, the mixing ratio of the thermoplastic resin and the cleaning aid is, for example, 30 parts or less of the cleaning aid with respect to 100 parts of the thermoplastic resin.
The amount is preferably from 5 to 20 parts, more preferably from 5 to 15 parts. When the amount of the cleaning aid decreases, the cleaning effect of the additive becomes more difficult to improve, and carbides and the like tend to be less likely to be removed. Yes, even if a large amount is added, the cleaning effect of the additive tends to be further improved, and carbides and the like tend to be easily removed. However, if it exceeds 30 parts, it is not economical.

In order to obtain the cleaning material for the inside of the heating tower of the resin molding machine of the present invention, a thermoplastic resin and a foaming agent may be mixed by a known method, and if necessary, the above additives may be mixed. For example, the following method can be used.

Method (1) As the simplest method, the necessary raw materials (thermoplastic resin, inorganic fibers and / or inorganic powder, foaming agent, cleaning aid such as stearic acid, etc.) are placed in a sturdy bag and shaken. It is sufficient to mix them alone, but it is not necessary to mix them completely (there is no difference in the cleaning effect even if each component slightly varies).

Here, since the foaming agent, stearic acid and the like are powders and do not easily adhere to the resin pellets, it is preferable that a small amount of liquid paraffin is added and adhered.

Method (2) Instead of a primitive method as in method (1), as a slightly advanced method, inorganic fiber and / or inorganic powder,
The foaming agent and stearic acid are difficult to handle because their shape is fibrous or powdery, so they are kneaded in advance with a resin that is the same as or different from the thermoplastic resin to be used and pelletized (such as After mixing (called a master batch), handling is easy.

As a method for mixing the pelletized raw materials, it is only necessary to put each pelletized raw material in a bag and shake it as in the above method (1), or to mix each pelletized raw material in a polybucket. You can just add the raw ingredients and stir by hand.

However, in such a method, it takes time and effort to produce a cleaning agent. Therefore, it is generally preferable to use a production apparatus called a tumbler. That is, if the pelletized raw material is put into the tumbler from above, the lid is placed on the tumbler, and the mixture is rotated to sufficiently mix (about 10 μm).
Stop rotation and take out product from below.

Thus, a product can be manufactured in a batch system. Considering the easiness of the work, it is good in terms of productivity and cost to work with the tumbler using the master batch as described above.

Method (3) The following method is also conceivable if necessary. This is a method of kneading all or a part of the materials into a thermoplastic resin, and is performed using an extruder called a ruder as a manufacturing apparatus.

Specifically, a glass fiber, a foaming agent and the like are supplied from a hopper to a ruder using a thermoplastic resin as a binder, kneaded and pelletized. At this time,
Since the foaming agent is decomposed (foamed) by the heat of the heating tower of the extruder, it is necessary to use a thermoplastic resin that melts at a temperature lower than the decomposition temperature of the foaming agent when kneading. Although there are many restrictions, the effect of using the cleaning agent obtained by this method (3) is as follows.
Or it is equivalent to that obtained by (2).

Among these methods, the method (1) or the method (2) in that they can be easily and inexpensively manufactured.
Is preferable, and the method (2) is more preferable.

In the cleaning method of the present invention, the cleaning material is supplied into a molding machine heating tower, and a purging operation (replacement work of a preceding resin or the like) is performed. This is a method in which heating and melting are performed in a tower, and washing is performed by the above-described action mechanism, and a method in which residues can be efficiently removed.

In the cleaning method of the present invention, there is a case where only one of the cleaning materials is used, and more efficient cleaning is performed by using a cleaning material having a different composition during the cleaning. Can be.

Next, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

Example 1 Using an acrylonitrile-butadiene-styrene copolymer (ABS) colored black with carbon black as a molding material, a 450-ton injection molding machine (heating tower temperature: 240 ° C., injection capacity: 1500 cc) was used in total. After about 6000 molded articles (0.4 kg per one) were produced, they were cleaned using 10 kg of the cleaning material of the present invention, which was manufactured in the mixing ratio shown in Table 2.

Next, using transparent ABS as a molding material, 8000 pieces (0.4 pieces per piece) were formed in the same manner as described above.
kg).

Of the 8000 molded products, the first 5
The occurrence rate of defective products (color mixture defects and foreign particle defects due to carbon black) out of 00 pieces was 5%.

Further, from the time when 10 kg of transparent ABS was molded, no defective product (poor color mixture) caused by the components of the cleaning material was observed at all.

Example 2 As a molding material, class VO in the UL94 standard was used.
45 with flame-retardant ABS (648 kg / day) corresponding to
A molded article is produced for 5 days by a 0-ton injection molding machine (heating tower temperature: about 240 ° C.), washed with 10 kg of the cleaning material of the present invention manufactured at the compounding ratio shown in Table 2, and washed for 2 days. After the production is suspended, the production is resumed for 5 days.

This production pattern was repeated for three months, but almost no corrosion was observed inside the heating tower or the nozzle of the molding machine. This will be described below with reference to FIG.

FIG. 1 is a schematic diagram for explaining the vicinity of a heating tower of an injection molding machine used in Example 2.

In FIG. 1, the heating tower is generally 3 to
It consists of eight temperature control zones (corresponding to zones 1 to 3 in FIG. 1), and the molding material supplied to the molding machine moves toward the tip of the heating tower. Since it is set higher as it is closer to the tip, the molding material is heated and melted as it moves.

Since the vicinity of the tip of the heating tower is particularly high in temperature, the molding material is usually partially decomposed in these zones, and the decomposition product starts to corrode. Screws and cylinders (barrels) in the heating tower of the molding machine for the inside of the heating tower when the production for three months according to the pattern is completed
JIS D0201 (metal surface treatment, 1
993, p. 578), it can be seen that when the molding machine is cleaned using the cleaning material of the present invention, almost no corrosion is observed.

Zone 1: Corrosion area 0.00% Zone 2: Corrosion area 0.00% Example 3 A colored red with a red iron oxide (pigment) as a molding material
BS (HB grade in UL94 standard) 3840
kg of a 650 ton injection molding machine (heating tower temperature 2
After producing a molded product (800 g per piece) at 50 to 210 ° C. and an injection capacity of 2000 cc, the product was washed with 15 kg of the cleaning material of the present invention manufactured at the compounding ratio shown in Table 2.

Subsequently, a molded article (800 g per piece) was produced using 3,840 kg of ABS colored white with titanium oxide (titanium white), but no defective article (color mixing defect) was found.

[0083]

[Table 2]

Comparative Example 1 In Example 1, instead of cleaning with the cleaning material of the present invention, a commercially available cleaning agent (Asaclean E manufactured by Asahi Chemical Industry Co., Ltd.) was used.
X) Washing with 25 kg, and further high density polyethylene 25
A transparent ABS molded product was produced in the same manner as in Example 1 except that the molded product was washed with kg.

The first 500 out of 8000 molded articles
The incidence of defective products (color mixture defects and foreign particle defects due to carbon black) was 30%.

Further, from the time when 10 kg of transparent ABS was molded, no defective product (poor color mixture) caused by a commercially available cleaning agent was observed at all.

Comparative Example 2 Production was carried out in the same manner as in Example 2 except that 25 kg of high-density polyethylene was used instead of using the cleaning material of the present invention. went. The results are shown below.

Zone 1: Corrosion area 0.07%, rating number 9.3-6 Zone 2: Corrosion area 0.07%, rating number 9.3-4 Comparative example 3 In Example 2, the cleaning material of the present invention Instead of using a cleaner, a cleaning agent dedicated to flame retardants (Z Clean S
29) Production was performed in the same manner as in Example 2 except that washing was performed using 10 kg and further washing was performed using 10 kg of high-density polyethylene, and the same comparison as in Example 2 was performed. The results are shown below.

Zone 1: Corrosion area 0.02%, rating number 9.8-6 Zone 2: Corrosion area 0.02%, rating number 9.8-4 Comparative example 4 In Example 3, the cleaning material of the present invention A molded article was produced in the same manner as in Example 1 except that 30 kg of ABS containing 20% of glass fiber was used instead of using, but the rate of occurrence of defective products (defective color mixture) among the first 100 pieces was 100%. %Met.

[0090]

The cleaning material for the heating tower of a resin molding machine according to the present invention is used for removing residues such as acidic substances, oxidizing substances, carbides, pigments and dyes remaining inside the heating tower of the molding machine. When it is efficiently removed and when an inorganic substance such as glass fiber or glass beads is blended, it has an action of removing rust generated by corrosion, but this effect is further enhanced by the foaming force (pressure).

Further, the cleaning method using the cleaning material for a heating tower in a resin molding machine according to the present invention is characterized in that an acid substance, an oxidizing substance, a carbide, a pigment,
This is a method that can efficiently remove residues such as dyes and remove rust.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining the vicinity of a heating tower of an injection molding machine used in Example 2.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification code FI C11D 3/37 C08L 101/00 (58) Field surveyed (Int.Cl. ⁷ , DB name) C08L 1/00-101/16 C08K 3/00-13/08 B29C 33/72 C11D 3/37

Claims (14)

(57) [Claims] 1. 100 parts by weight of a thermoplastic resin and 0.1 parts of a foaming agent.
And 001-50 parts by weight seen including, thermoplastic resin is preceded tree
A cleaning material for a heating tower in a resin molding machine, which is a mixture of a resin incompatible with fat and a resin compatible with fat . 2. The foaming agent is an inorganic compound, and
The gas generated by foaming is reducing and / or
The cleaning material according to claim 1, which exhibits potash. 3. The foaming agent is an inorganic compound, and
The residue generated by foaming is reduced and / or
The cleaning material according to claim 1, which exhibits potash. 4. The foaming agent is an organic compound, and
The gas generated by foaming is reducing and / or alkaline
The cleaning material according to claim 1, which exhibits resiliency. 5. The foaming agent is an organic compound, and
The residue generated by foaming is reduced and / or
The cleaning material according to claim 1, which exhibits potash. 6. Inorganic fibers and / or inorganic powders 0 to 5
The cleaning material according to any one of claims 1 to 5 , comprising 0 parts by weight. 7. Organic fibers and / or organic powders 0 to 5
The cleaning material according to any one of claims 1 to 6 , comprising 0 parts by weight. 8. Metal fibers and / or metal powders 0 to 2
The cleaning material according to any one of claims 1 to 7 , comprising 5 parts by weight. 9. The cleaning material according to any one of claims 1-8 comprising 0 to 30 parts by weight alkaline material. 10. The method according to claim 1, comprising 0 to 30 parts by weight of a reducing agent.
The cleaning material according to any one of claims 9 to 9 . 11. The cleaning material according to any one of claims 1 to 10 including a cleaning aid 0-30 parts by weight. 12. A thermoplastic resin which is incompatible with the preceding resin.
100 parts by weight of a compatible thermoplastic resin mixture, 0.001 to 50 parts by weight of a foaming agent, 50 parts by weight or less of inorganic fiber and / or inorganic powder, 50 parts by weight or less of organic fiber and / or organic powder, metal fiber and / Or metal powder 25
A cleaning material for a heating tower in a resin molding machine, containing not more than 30 parts by weight of a cleaning aid and not more than 30 parts by weight. 13. The cleaning material according to claim 12 , comprising 30 parts by weight or less of an alkaline substance and 30 parts by weight or less of a reducing agent. 14. After supplying the cleaning material for a resin molding machine heating tower according to any one of claims 1 to 13 into the molding machine heating tower, the cleaning material is physically separated in the heating tower of the molding machine. And / or washing the inside of the heating tower of the molding machine by chemically foaming.