JP7401089B2 - Purge additives and purging agents - Google Patents

Description

The present invention relates to a purge additive added to a base resin used for cleaning a molding machine, and a purge agent in which this purge additive is added to the base resin.

In resin molding, when changing the color or material of the resin, a purging agent is supplied to the molding machine to clean it. For example, in Patent Document 1, in order to remove a plasticizer, a detergent containing a surfactant, water, and a nonpolar organic solvent is used.

Japanese Patent Application Publication No. 2002-239482

BACKGROUND ART In resin molding, the resin is carbonized by the heat generated during molding, resulting in burnt resin sometimes adhering to the surface of the molding machine (for example, the screw of an injection molding machine). An object of the present invention is to provide a purge additive that facilitates the removal of burnt resin, reduces the amount of purge agent used, and shortens cleaning time while maintaining cleaning performance.

The first invention of the present application is a purge additive added to a colorless base resin used for cleaning a molding machine, which comprises a nonionic surfactant, a cationic surfactant, oil, and borax water. have Here, in addition to the nonionic surfactant and the cationic surfactant, an anionic surfactant can be contained.

The total content of surfactants contained in the purge additive can be 1 to 60% by mass. Further, the content of borax water can be 20 to 80% by mass. The content of borax in the borax water can be 0.001 to 5% by mass.

The purge agent according to the second invention of the present application includes the purge additive according to the first invention of the present application, and a base resin to which the purge additive is added. Here, the amount of the purge additive added can be less than 30% by mass.

According to the present invention, burnt resin attached to the surface of a molding machine can be easily removed, and the amount of purge agent used can be reduced while maintaining cleaning performance, thereby shortening the cleaning time.

In this embodiment, the purge agent is supplied to the molding machine used for molding the resin in order to clean it, and is made by adding a purge additive to the base resin (resin pellets). As the molding machine, for example, an injection molding machine or an extrusion molding machine is used. In this embodiment, an uncolored and transparent resin is used as the base resin, and for example, polycarbonate resin or acrylic resin (polymethyl methacrylate resin (PMMA), etc.) can be used.

The purge additive is a liquid additive and has a surfactant, oil, and borax water. In the present embodiment, the amount of the purge additive added is the ratio of the mass Wpa of the purge additive to the mass Wpt of the purge agent (base resin and purge additive) (=100×Wpa/Wpt). The amount can be determined as appropriate.

Even if the amount of the purge additive added is too large, the performance of removing burnt resin will not change much, so the amount of the purge additive added is preferably less than 30% by mass, and preferably 20% by mass or less. More preferred. On the other hand, if the purge additive of this embodiment is added to the base resin, burnt resin can be removed, so the lower limit of the amount of the purge additive added is not particularly limited, but the purge agent In order to reduce the amount of purge additive used, the amount of purge additive added is preferably 1% by mass or more, and more preferably 3% by mass or more.

Types of surfactants included in the purge additive include anionic surfactants, nonionic surfactants, and cationic surfactants, and a mixture of multiple types of surfactants is used. By using a surfactant, when molding after changing the color of the resin, it is possible to make it easier to remove the coloring material that has adhered to the surface of the molding machine (the coloring material contained in the resin before changing the color) from the molding machine. can. In addition, in order to remove burnt resin attached to the surface of the molding machine, it is preferable to use a nonionic surfactant and a cationic surfactant in combination. Activators can also be used.

Examples of nonionic surfactants include ester types such as glyceryl laurate, glyceryl monostearate, sorbitan fatty acid ester, and sucrose fatty acid ester, polyoxyethylene alkyl ether, pentaethylene glycol monododecyl ether, and octaethylene glycol monododecyl. Ether types such as ether, polyoxyethylene alkylphenyl ether, octylphenol ethoxylate, nonylphenol ethoxylate, polyoxyethylene polyoxypropylene glycol, polyoxyethylene glycerin fatty acid ester, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene Ester ether types such as sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene hexitane fatty acid ester, and sorbitan fatty acid ester polyethylene glycol, and alkanolamides such as lauric acid diethanolamide, oleic acid diethanolamide, stearic acid diethanolamide, and cocamide DEA. and alkyl glycosides such as octyl glucoside, decyl glucoside, and lauryl glucoside (lauryl dimethylamine oxide, etc.).

Examples of cationic surfactants include tetramethylammonium chloride, tetramethylammonium hydroxide, tetrabutylammonium chloride, dodecyldimethylbenzylammonium chloride, alkyltrimethylammonium chloride, octyltrimethylammonium chloride, decyltrimethylammonium chloride, and dodecyltrimethylammonium chloride. , tetradecyltrimethylammonium chloride, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, alkyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzalkonium chloride, benzalkonium bromide , quaternary ammonium salts such as benzethonium chloride, dialkyldimethylammonium chloride, didecyldimethylammonium chloride, and distearyldimethylammonium chloride, monomethylamine salt, dimethylamine salt, trimethylamine salt, and ethylamine salt (polyoxyethylene laurylamine, etc.) Examples include alkylamine salt types, such as, and substances having a pyridine ring such as butylpyridinium chloride, dodecylpyridinium chloride, and cetylpyridinium chloride.

Examples of anionic surfactants include sodium octoate, sodium decanoate, sodium laurate, sodium myristate, sodium palmitate, sodium stearate, PFOA, perfluorononanoic acid, sodium N-lauroylsarcosine, sodium cocoylglutamate, alpha Carboxylic acid types such as sulfo fatty acid methyl ester salts, sodium 1-hexane sulfonate, sodium 1-octanesulfonate, sodium 1-decanesulfonate, sodium 1-dodecanesulfonate, perfluorobutanesulfonic acid, sodium linear alkylbenzenesulfonate , sodium toluenesulfonate, sodium cumenesulfonate, sodium octylbenzenesulfonate, DBS, sodium naphthalenesulfonate, disodium naphthalene disulfonate, trisodium naphthalenetrisulfonate, sodium butylnaphthalenesulfonate, PFOS, α-olefin sulfonate Sulfonic acid types such as sodium, sulfuric acid ester types such as sodium lauryl sulfate, sodium myristyl sulfate, sodium laureth sulfate, sodium polyoxyethylenealkylphenol sulfonate, and ammonium lauryl sulfate, and phosphoric acid types such as lauryl phosphate, sodium lauryl phosphate, and potassium lauryl phosphate. Examples include acid ester types.

As described above, in the purge additive of this embodiment, at least a nonionic surfactant and a cationic surfactant are used as the surfactant. Here, the content of each surfactant in the purge additive can be determined as appropriate, but is preferably 1 to 30% by mass. Regarding the plurality of types of surfactants, the content of each surfactant may be the same or different from each other. The total content of all surfactants contained in the purge additive is preferably from 1 to 60% by weight. If the content (total) of all surfactants is too high, the purge additive will remain and affect the next resin, so the content (total) of all surfactants should be 60% by mass or less. preferable.

The oil contained in the purge additive is used as an antifoaming agent to suppress foaming of the surfactant. Here, in order to stabilize the cleaning performance of the purging agent, it is preferable to solubilize (disperse) the oil in the purging agent. Considering this point, for example, essential oil or silicone oil can be used as the oil. The oil content in the purge additive can be determined as appropriate, but is preferably 1 to 30% by mass. When the oil content is less than 1% by mass, it becomes difficult to suppress foaming of the surfactant. In addition, since there is no need to use an excessive amount of oil in order to suppress foaming of the surfactant, the oil content is preferably 30% by mass or less.

The borax water contained in the purge additive is a mixture of borax and water as a solvent. As the water, for example, purified water can be used. The content of borax in the borax water can be determined as appropriate, but is preferably 0.001 to 5% by mass, more preferably 0.001 to 1% by mass.

The content of borax water in the purge additive can be determined as appropriate, but is preferably 20 to 80% by mass. If the content of borax water is less than 20% by mass, it becomes difficult to mix the purge additive into the base resin. Furthermore, if the borax water content is 80% by mass or more, the borax may precipitate before use, impairing the cleaning effect.

The content of each component (surfactant, oil, and borax water) constituting the purge additive is, for example, within the range of the content of each component described above, and the total content of all components is 100% by mass. It should be adjusted so that

By cleaning the molding machine using a purge agent obtained by adding the above-mentioned purge additive to the base resin, burnt resin attached to the surface of the molding machine can be easily removed. Furthermore, when cleaning a molding machine using a purge agent, the amount of the purge agent used can be reduced while maintaining cleaning performance. As a result, the time required to clean the molding machine can be shortened, and the work of changing resin types and colors can be done smoothly.

Examples of the present invention will be described below, but the present invention is not limited to the following examples.

(Example 1)
There are three types of surfactants included in the purge additive: sodium α-olefin sulfonate (anionic surfactant), lauryldimethylamine oxide (nonionic surfactant), and polyoxyethylene laurylamine (cationic surfactant). was used. Essential oil (turpentine oil) was used as the oil contained in the purge additive. The borax water contained in the purge additive was prepared by mixing 5% by mass of borax and 95% by mass of purified water. The content of each component (each surfactant, oil, and borax water) in the purge additive is shown in Table 1 below.

A purge agent was prepared by adding the above-mentioned purge additive to a base resin (polycarbonate resin; PC), and the injection molding machine was cleaned by supplying this purge agent to the injection molding machine. In this example, the amount of the purge additive added was 3% by mass.

(Example 2)
In this example, a purge additive having the same components and content as in Example 1 was used, and the amount of the purge additive added was 5% by mass. Other conditions (for example, cleaning conditions) were the same as in Example 1.

(Example 3)
In this example, a purge additive having the same components and content as in Example 1 was used, and the amount of the purge additive added was 20% by mass. Other conditions (for example, cleaning conditions) were the same as in Example 1.

(Example 4)
In this example, a purge additive having the same components and content as in Example 1 was used, and the amount of the purge additive added was 30% by mass. Other conditions (for example, cleaning conditions) were the same as in Example 1.

(Example 5)
In this example, two types of surfactants, a nonionic surfactant (lauryl dimethylamine oxide) and a cationic surfactant (polyoxyethylene laurylamine), were used, and the content of the nonionic surfactant was 5% by mass. %, and the content of the cationic surfactant was 15% by mass. Except for the surfactant, each component and content of the purge additive, the amount of the purge additive added, and the cleaning conditions were the same as in Example 1.

(Example 6)
In this example, the content of borax in the borax water was 0.25% by mass. Other conditions were the same as in Example 1.

(Example 7)
In this example, the content of borax in the borax water was 0.30% by mass. Other conditions were the same as in Example 1.

(Example 8)
In this example, the content of borax in the borax water was 1.00% by mass. Other conditions were the same as in Example 1.

(Example 9)
In this example, the content of borax in the borax water was 3.50% by mass. Other conditions were the same as in Example 1.

(Comparative example 1)
In this comparative example, only an anionic surfactant (sodium α-olefin sulfonate) was used as the surfactant, and the content of the anionic surfactant was 20% by mass. The other components (oil and borax water) and content of the purge additive, the amount of the purge additive added, and the cleaning conditions were the same as in Example 1.

(Comparative example 2)
In this comparative example, an anionic surfactant (sodium α-olefin sulfonate) and a nonionic surfactant (lauryl dimethylamine oxide) were used as surfactants, and the content of each surfactant was 15% by mass. . The other components (oil and borax water) and content of the purge additive, the amount of the purge additive added, and the cleaning conditions were the same as in Example 1.

(Comparative example 3)
In this comparative example, an anionic surfactant (sodium α-olefin sulfonate) and a cationic surfactant (polyoxyethylene laurylamine) were used as surfactants, and the content of each surfactant was 15% by mass. . The other components (oil and borax water) and content of the purge additive, the amount of the purge additive added, and the cleaning conditions were the same as in Example 1.

(Comparative example 4)
In this comparative example, water not containing borax (purified water used in Example 1) was used instead of the borax water described in Example 1. Other than this point, it was the same as Example 1.

(Evaluation of burnt resin removal performance)
Burnt resin was previously attached to the surface of a screw used in an injection molding machine, and a purging agent was supplied to the injection molding machine including this screw to clean the injection molding machine. In order to attach burnt resin to the surface of the screw, injection molding was performed using polyethylene resin colored wine red in an injection molding machine, and burnt resin was attached to the entire surface of the screw.

A purge agent was supplied to the injection molding machine, and the purge agent was discharged from the injection molding machine. Here, the temperature of the injection molding machine is the same in all Examples and Comparative Examples, and the purging agent is supplied to the injection molding machine until the color of the purging agent discharged from the injection molding machine changes from wine red to colorless. I continued to do so. That is, the supply of the purge agent was stopped when the color of the purge agent changed from wine red to colorless.

The usage amount Ws of the purge agent supplied to the injection molding machine was measured from when the purge agent started being supplied to the injection molding machine until the color of the purge agent changed from wine red to colorless. Then, the purge amount PA was calculated based on this usage amount Ws. Purge amount PA is the amount of base resin used when cleaning an injection molding machine using only base resin (polycarbonate resin; PC) to which no purge additive is added (hereinafter referred to as "standard example"). Wr is used as a reference (100%), and is defined by the following formula (1). The usage amount Wr is the usage amount of the base resin until the color of the base resin changes from wine red to colorless, and was measured in advance.

PA=(100×Ws)/Wr...(1)

After cleaning the injection molding machine using a purging agent, the surface of the screw was visually observed, and the burnt resin removal performance was evaluated based on the adhesion state of the burnt resin. Here, the evaluation is given as "〇" when the adhesion of burnt resin cannot be confirmed, and the evaluation is given as "x" when the adhesion state of burnt resin does not change much between before and after cleaning. When the evaluation did not reach "〇" even though it could be removed, the evaluation was set as "△".

The results of the above evaluation are shown in Tables 2 to 4 below. Table 2 below shows the results of evaluating the burnt resin removal performance of Examples 1 to 4 and the reference example described above. Table 2 below considers the influence of the amount of purge additive added on burnt resin removal performance and purge amount PA.

According to the results shown in Table 2 above, it was found that burnt resin could be removed by using the purge additives of Examples 1 to 4. Further, the purge amount PA of Examples 1 to 4 was approximately half of the purge amount (100%) of the reference example, and it was found that the amount of the purge agent to which the purge additive was added could be reduced. Here, as in Example 1, even if the amount of the purge additive added was 3% by mass, the burnt resin could be removed and the purge amount PA could be reduced to 57%. On the other hand, as shown in Examples 2 to 4, even if the amount of purge additive added was increased to 5, 20, and 30% by mass, the purge amount PA remained constant. It was found that it had no effect on

However, it was found that when the amount of the purge additive added was 30% by mass as in Example 4, the transparency of the purge agent discharged from the injection molding machine was slightly reduced. Considering this point, it is preferable that the amount of the purge additive added is less than 30% by mass.

Table 3 below shows the results of evaluating the burnt resin removal performance of Examples 1 and 5 and Comparative Examples 1 to 3 described above. Table 3 below considers the influence of the type of surfactant on the burnt resin removal performance.

According to the results shown in Table 3 above, it was found that burnt resin adhering to the surface of the screw could be removed by using at least a nonionic surfactant and a cationic surfactant as the surfactant contained in the purge additive. . On the other hand, in Comparative Examples 1 to 3 in which a nonionic surfactant and a cationic surfactant were not used in combination, it was found that burnt resin could not be removed. For this reason, as the surfactant contained in the purge additive, a nonionic surfactant and a cationic surfactant may be used in combination, or a nonionic surfactant, a cationic surfactant, and an anionic surfactant may be used in combination. By doing so, the burnt resin can be removed.

Table 4 below shows the purge amounts in Examples 6 to 9 and Comparative Example 4 described above. Table 4 below considers the effect of the borax content in the borax water on the purge amount.

According to the results shown in Table 4 above, using water containing borax (borax water) reduces the purge amount PA more than using water that does not contain borax (simply purified water). was completed. That is, the amount of the purge agent to which the purge additive is added can be reduced, the time for cleaning the molding machine can be shortened, and the work of changing the type or color of resin can be performed smoothly. Here, in order to further reduce the purge amount PA, it is preferable that the content of borax is 0.30 or less.

Claims (7)

A purge additive added to a colorless base resin used for cleaning molding machines,
a nonionic surfactant and a cationic surfactant;
oil and
Borax water and
A purge additive comprising: The purge additive according to claim 1, further comprising an anionic surfactant in addition to the nonionic surfactant and the cationic surfactant. The purge additive according to claim 1 or 2, wherein the total content of surfactants contained in the purge additive is 1 to 60% by mass. The purge additive according to any one of claims 1 to 3, characterized in that the content of the borax water is 20 to 80% by mass. The purge additive according to any one of claims 1 to 4, wherein the borax content in the borax water is 0.001 to 5% by mass. a purge additive according to any one of claims 1 to 5;
a base resin to which the purge additive is added;
A purging agent characterized by having the following. The purge agent according to claim 6, wherein the amount of the purge additive added is less than 30% by mass.