JPH0443092B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Field of industrial application The present invention relates to a method for producing a thermoplastic resin masterbatch containing a high concentration of a surfactant. This invention relates to a method for producing a thermoplastic resin masterbatch containing a high concentration of (B) Prior Art Conventionally, thermoplastic resin molded products have been given an antistatic effect to prevent stains due to adsorption of dust and the like. In order to impart an antistatic effect, a method of mixing an antistatic agent into a thermoplastic resin is adopted. A thermoplastic resin molded product containing an antistatic agent is produced by purchasing a thermoplastic resin containing an antistatic agent and molding it into a predetermined shape. However, the current situation is that thermoplastic resins containing antistatic agents are more expensive than raw resins that do not contain antistatic agents, and therefore the final molded product must also be more expensive. Therefore, recently, the price of molded products has been reduced by using a mixture of a masterbatch containing a high concentration of antistatic agent and a raw material resin (also called diluted resin). Conventionally, it is preferable that the amount of antistatic agent contained in a masterbatch is as large as possible. but,
Generally, the amount of antistatic agent that can be contained is less than 20% by weight, and it has not been possible to obtain more than 20% by weight. This is achieved by putting a large amount of antistatic agent and thermoplastic resin into an extruder separately, and extruding them while applying heat and pressure to melt and mix them. Because slipping and surging occur, stable discharge cannot be obtained, and as a result, granules cannot be granulated into a uniform shape and cannot be used as a masterbatch.
That is, the advantage of a masterbatch, that is, the ability to mix the antistatic agent with the raw material resin to accurately mix the antistatic agent, cannot be achieved, and it becomes impossible to use it as a masterbatch. For this reason, various methods have been attempted to obtain a masterbatch containing a higher concentration of antistatic agent. For example, in JP-A No. 57-30746, a highly fluid thermoplastic resin was used as the masterbatch, and an antistatic agent was added in a higher concentration to prevent slippage in the extruder. A method of manufacturing a masterbatch is disclosed. However, the masterbatch obtained by this manufacturing method has a negative impact on the final molded product because the thermoplastic resin blended into the masterbatch is extremely fluid compared to commonly used raw material resins.
It has the disadvantage that it is difficult to obtain molded products with physical properties (for example, strength, etc.) equivalent to those of the raw resin. (c) Problems to be Solved by the Invention Therefore, the present invention aims to prevent slippage in an extruder while using a thermoplastic resin that has fluidity equivalent to that commonly used as a raw material resin. The object of the present invention is to provide a method for producing a masterbatch containing a higher concentration of surfactant. (d) Means and operation for solving the problems That is, the present invention does not separately charge the thermoplastic resin and the surfactant into the extruder and mix them in the extruder, but instead charge the thermoplastic resin and the surfactant into the extruder. The present invention relates to a method for producing a surfactant-containing thermoplastic resin masterbatch by preparing a composition in which a thermoplastic resin and a surfactant are uniformly mixed in advance and feeding the composition into an extruder. . The surfactants used in the present invention include anionic surfactants such as fatty acid salts, higher alcohol sulfate ester salts, alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkyl sulfonates, and higher alcohol phosphate ester salts;
Cationic surfactants such as primary amine salts, ethanolamine ester salts, tetraalkylammonium salts, and pyridium salts; amphoteric surfactants such as betaine and aminoalkyl sulfate ester salts; higher alcohol ethylene oxide adducts; fatty acid ethylene oxide adducts; Nonionic surfactants such as alkylamine ethylene oxide adducts, glycerin monofatty acid esters, pentaerythritol fatty acid esters, and sorbitol fatty acid esters are used. In the present invention, thermoplastic resins include polypropylene, polyethylene, ethylene-vinyl acetate copolymer, polystyrene, acrylonitrilo-styrene copolymer, acrylonitrilo-butadiene-styrene copolymer, polymethyl methacrylate,
Polyacrylic acid ester, polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol, polyvinyl acetal, polyvinylidene acetate, polyurethane, polyamide, polycarbonate, saturated polyester, polyacetal, polyphenylene oxide, polyphenylene ether, polysulfone,
Polyether sulfone, polyphenylene sulfide, etc. are used. In the present invention, the fluidity (melt flow index) of the thermoplastic resin may be any level, but especially the melt flow index (JIS
K7210A method, temperature 220℃, load 10Kg) is 80g/10
minutes, more preferably 50 g/10 minutes or less. The melt flow index
When a thermoplastic resin exceeding 80 g/10 minutes is used, the surfactant can be contained at a high concentration by a known method of charging the thermoplastic resin and the surfactant separately into an extruder. This is because you can obtain a master batch. In order to obtain a molten composition in which a surfactant and a thermoplastic resin are uniformly mixed, the surfactant may be made into a liquid state and the thermoplastic resin may be made into a molten state and kneaded together. To make a surfactant into a liquid state, one that is liquid at room temperature can be used as is, but one that is solid at room temperature in the form of powder or flakes may be heated.
To melt the thermoplastic resin, heating may be performed at the melting temperature of the thermoplastic resin. Therefore, various heating temperatures must be set depending on the type of thermoplastic resin, but it is usually in the range of 150 to 280°C. In order to uniformly mix the surfactant and thermoplastic resin, a conventionally known kneading machine such as a kneader or a ribbon blender may be used. Surfactants and thermoplastic resins may be in a liquid or molten state when being added to a kneader or other kneading machine, or they may be added to a kneader or other kneader in a solid state by installing a heating device. It may be put into a liquid or molten state in a kneader or the like. When a surfactant is mixed with a molten thermoplastic resin, it is heated to about the melting temperature of the thermoplastic resin, and if the temperature exceeds 240°C, there is a risk of ignition, so the mixing should not be done in an inert atmosphere. There is a need to do. To create an inert atmosphere, the kneader may be filled with nitrogen gas, argon gas, or the like. The molten composition thus obtained may be cooled and solidified, if desired, to form a solid composition.
The solid composition may be in the form of a rod, or may be in the form of powder or granules so that it can be easily fed into an extruder. Melt compositions and solid compositions contain surfactants 20 to 95
A blending ratio of 80 to 5% by weight of the thermoplastic resin and the thermoplastic resin is optimal in the present invention. This fully demonstrates the feature of the present invention that if the blending ratio of surfactant is less than 20% by weight, only a masterbatch containing a low concentration of surfactant can be obtained, but a masterbatch containing a high concentration of surfactant can be obtained. This is because it cannot be done. However, it goes without saying that the present invention can also be applied to the production of a masterbatch containing a surfactant at a low concentration. After preparing a molten composition or a solid composition, it is put into an extruder, and in the extruder, pressure and, if necessary, heat are applied to make it fluid and extrusion processing is performed. When charging the molten composition into an extruder, heat may not be applied if the molten composition does not lose desired fluidity in the extruder. Pressure and heat may need to be applied when the solid composition is introduced into the extruder or when the molten composition loses its desired fluidity in the extruder. The extruder used in the present invention refers to one equipped with a pressure section such as a screw, plunger, or gear, and a molding section such as a die. Typically, it consists of a heating section that heats a molten composition or a solid composition, a screw section that advances the composition under pressure, and a die that molds the composition into a predetermined shape. In the present invention, since a composition in which a thermoplastic resin and a surfactant are uniformly mixed is prepared in advance before being charged into the extruder, the thermoplastic resin and surfactant are mixed together in the extruder, especially in the screw section. does not cause slips. For example, if a solid thermoplastic resin and a powder or liquid surfactant are separately charged into an extruder, the thermoplastic resin and surfactant may slip in the extruder, especially in the screw section, causing the die to die. The discharge from the mold becomes unstable, making it impossible to obtain a molded product with a constant shape. The composition introduced into the extruder is given a certain shape by a die, and is formed into a filament having a circular or square cross section, for example. Then, it is immediately cooled and then cut into a predetermined length for granulation (obtaining granules of a predetermined shape) to obtain a masterbatch. (e) Example Using a surfactant as an antistatic agent and a thermoplastic resin shown in Table 1, both were brought into a liquid state and a molten state at respective mixing temperatures, and mixed uniformly to prepare a molten composition. did. Thereafter, the molten composition was cooled and solidified to obtain a solid composition. By putting this solid composition into a single-screw extruder (equipped with one screw) and extruding it, the mixing ratio of the antistatic agent and thermoplastic resin and the kneading properties as shown in Table 1 can be adjusted. Obtained master badge. Furthermore, an attempt was made to extrude the molten composition by putting it into an extruder in its molten state without converting it into a solid composition, but the same results as those shown in Table 1 were obtained.

【table】

【table】

[Table] Next, as comparative examples, Examples 1, 3, 7, 12,
Extrusion processing was attempted using surfactants and thermoplastic resins corresponding to Nos. 14 and 15, which were separately charged into a twin-screw extruder (equipped with two screws). The results are shown in Table 2. Further, when a single screw extruder similar to that in the example is used, the kneading property is further reduced by about 50%.

【table】

[Table] As is clear from the above examples and comparative examples,
According to the examples, a masterbatch containing a high concentration of surfactant (20% by weight or more) is obtained, whereas in the comparative example, a masterbatch having a surfactant content of about 20% by weight at most is obtained, If the content is higher than that, it becomes impossible to obtain a masterbatch of a certain shape using an extruder. Next, as an application example, using the masterbatch obtained in the example, the same type of resin was used as the raw material resin,
The mixture was diluted at the weight ratio shown in Table 3 to obtain a molded product. Table 3 shows the physical properties of the molded product obtained.

【table】

[Table] As is clear from the above examples and application examples,
The masterbatch according to the example can be used in the same manner as a conventional masterbatch containing a low concentration of antistatic agent, and the physical properties of the obtained molded product were also satisfactory. (F) Effects of the Invention According to the method for producing a masterbatch according to the present invention, a masterbatch containing a high concentration (20 to 95% by weight) of a surfactant can be easily produced using a conventional extruder. Furthermore, since the surfactant that was conventionally mixed during extrusion processing is mixed in advance with the thermoplastic resin before extrusion processing, even surfactants that cannot be mixed during extrusion processing can be mixed and used. be able to. In addition, the method according to the specific invention of the present application, after adjusting the molten composition, maintains it as it is (i.e., molten state).
Since the method of the second invention is such that the molten composition is solidified to obtain a solid composition and then charged into the extruder, the process is streamlined. Although the above description has mainly focused on the case where a surfactant with an antistatic effect (antistatic agent) is used, the present invention also applies to the use of other surfactants, such as a surfactant with a lubricating effect (a lubricant). ) can also be suitably used.

Claims (1)

[Claims] 1 A molten composition is prepared by uniformly mixing a liquid surfactant and a molten thermoplastic resin, and then the molten composition is fed into an extruder in a molten state. 1. A method for producing a thermoplastic resin masterbatch containing a surfactant, which comprises molding by extrusion under pressure and then granulating it into a predetermined shape. 2 Melt flow index of thermoplastic resin (JIS K7210A method, temperature 220℃, load 10Kg) is 80
A method for producing a thermoplastic resin masterbatch containing a surfactant according to claim 1, wherein the thermoplastic resin masterbatch has a heating rate of 1 g/10 minutes or less. 3 Melt flow index of thermoplastic resin (JIS K7210A method, temperature 220℃, load 10Kg) is 50
3. The method for producing a thermoplastic resin masterbatch containing a surfactant according to claim 2, wherein the thermoplastic resin masterbatch has a surfactant content of 1 g/10 minutes or less. 4 The melt composition contains 20 to 95% by weight of surfactant and 80% by weight of surfactant.
A method for producing a surfactant-containing thermoplastic resin masterbatch according to claim 1, which comprises 5% by weight of a thermoplastic resin. 5 After uniformly mixing the liquid surfactant and the molten thermoplastic resin to prepare a molten composition, the molten composition is solidified by cooling to form a solid composition, and then the solid composition is Manufacture of a surfactant-containing thermoplastic resin masterbatch, which is characterized in that the material is put into an extruder in a solid state, extruded under the action of heat and pressure, and then granulated into a predetermined shape. Method. 6 Melt flow index of thermoplastic resin (JIS K7210A method, temperature 220℃, load 10Kg) is 80
The method for producing a thermoplastic resin masterbatch containing a surfactant according to claim 5, wherein the thermoplastic resin masterbatch has a melting rate of 1 g/10 minutes or less. 7 Melt flow index of thermoplastic resin (JIS K7210A method, temperature 220℃, load 10Kg) is 50
7. The method for producing a thermoplastic resin masterbatch containing a surfactant according to claim 6, wherein the thermoplastic resin masterbatch has a melting rate of 1 g/10 minutes or less. 8 The solid composition contains 20 to 95% by weight of surfactant and 80
6. A method for producing a surfactant-containing thermoplastic resin masterbatch according to claim 5, comprising ~5% by weight of a thermoplastic resin.