JPS6113487B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for easily obtaining a fatty acid cellulose ester resin molded article having an excellent pattern. More specifically, a saponified fatty acid cellulose ester resin is used as a mottled resin for fatty acid cellulose ester resin moldings, and this and a fatty acid cellulose ester resin are mixed and heated to form a fatty acid cellulose with a pattern. The present invention relates to a method for producing an ester resin molded product. Conventionally, there are the following methods for obtaining a fatty acid cellulose ester resin molded product having a pattern. In other words, when two or more types of fatty acid cellulose ester resins with different plasticizer contents are mixed and heat molded, the fatty acid cellulose ester resin, which has a low plasticizer content and a high melting temperature, is not completely melted and becomes a mottled color. This is a method of obtaining a molded product with a pattern by leaving the pattern. However, this method has the following drawbacks and problems. 1. Since the difference in melting temperature cannot be made too large, if the molding temperature is raised, the resin that will form the pattern will also melt and mix, resulting in the pattern disappearing. For this reason, it is necessary to mold at a lower temperature than the normal molding temperature, which results in insufficient filling of resin into the mold, causing sink marks in the molded product, and deterioration of physical properties such as a decrease in impact value due to molding distortion. may cause a decline. 2. In a screw-type thermoplastic resin molding machine, since the screw is used for kneading, shearing force from the screw acts on the resin that has a low plasticizer content and a high melting temperature, which is blended for the mottled color of the pattern.
Therefore, this resin for mottled color is mixed and the desired pattern cannot be obtained. For this reason, resin molded articles having patterns are manufactured using a plunger type injection molding machine or the like. For this reason, the capacity of the molding machine is smaller than that of a screw-type injection molding machine, making it difficult to produce large molded products, and the plasticizing ability is low, resulting in poor work efficiency. Another method is to use a special device to produce the pattern. That is, this is a manufacturing method that involves devising the screw shape of a thermoplastic resin molding machine and using equipment such as special screws, nozzles, adapters, and dies for producing patterns. However, the pattern obtained by this method is constant, and it becomes necessary to manufacture a special device to create a new pattern each time the pattern is updated.
There are major disadvantages in terms of cost. The present inventors have conducted intensive research on a method for obtaining fatty acid cellulose ester resin molded products having arbitrary patterns using any general-purpose thermoplastic resin molding machine without using any special equipment to create patterns. As a result, we arrived at this invention. That is, the present invention was achieved based on the knowledge that when a fatty acid cellulose ester resin is saponified, its behavior when melted under heat is completely different from that of an unsaponified fatty acid cellulose ester resin. The present invention is a method for producing a fatty acid cellulose ester resin molded product, which comprises obtaining a molded product having a pattern by mixing a fatty acid cellulose ester resin and a saponified fatty acid cellulose ester resin and heat-molding the mixture. exists in The fatty acid cellulose ester used in the present invention is obtained by esterifying some or all of the hydroxyl groups of cellulose with an organic acid, and preferred are cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. Particularly preferred are cellulose acetate with 37 to 44% acetyl groups, cellulose acetate propionate with 54 to 57% propionyl groups and 6 to 10% acetyl groups, and cellulose acetate propionate with 34 to 39% butyryl groups and 13 acetyl groups.
~15% cellulose acetate butyrate, etc. The fatty acid cellulose ester resin used in the present invention may be produced by any known method, for example the following method. 1. Mix and stir the fatty acid cellulose ester together with a plasticizer, stabilizer, and colorant in a solvent by a method called a casting method, evaporate the solvent from the dissolved dove, and form it into a film, sheet, fiber, etc. Cut as desired and use as molding resin. 2. The fatty acid cellulose ester is mixed with a plasticizer, a stabilizer, a solvent, and a coloring agent by a method called a wet method or a block method, and then made into a uniform cake shape using a kneading machine such as a milling machine or a roll machine, and then the solvent is evaporated to form a sheet. 3. A plasticizer, stabilizer, and coloring agent were added to the fatty acid cellulose ester by a method called a dry method, and the mixture was mixed using a ribbon blender, Henschel mixer, etc., and dried. After that, uniform pellets, spheres,
It is molded into rods or sheets and cut as needed to make resin for molding. The appropriate blending ratio of the plasticizer in the fatty acid cellulose resin used in the present invention is 5 to 100 parts by weight per 100 parts by weight of the fatty acid cellulose ester. As plasticizers, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, dimethoxyethyl phthalate,
Phthalate esters such as dimethoxyhexyl phthalate, phosphate esters such as triphenyl phosphate and tricresyl phosphate, glycerin derivatives such as triacetin and tributyrin, methyl phthalylethyl glycolate, ethyl phthalylethyl glycolate, butyl phthalyl butyl Glycolic acid derivatives such as glycolate, sulfonic acid derivatives such as p-toluenesulfonamide and toluenesulfone-N-ethylamide, other adipic acid derivatives, azelaic acid derivatives, diglycerin, polyglycerin, pentaerythritol, dipentaerythritol, tolylmethylol Polyhydric alcohol lower fatty acid esters of propane, trimethylolethane, ditriethylolethane, ditrimethylolpropane, sorbitol, mannitol and tris(2-hydroxylethyl)isocyanurate, 1,
Plasticizers commonly used in fatty acid cellulose ester resins, such as 2,3-butane tricarboxylic acid triester and bisphenol A type epoxy resin, can be used. In addition, various stabilizers are added to the fatty acid cellulose ester resin to prevent thermal deterioration and heat discoloration during hot molding, but the fatty acid cellulose ester resin used in the present invention also contains phosphorous ester, A necessary amount of general commercially available stabilizers such as epoxidized oil, epoxy resin, hindered phenol, thioether, etc. is added to prevent thermal deterioration and thermal discoloration. Furthermore, in order to color it to a desired color, known dyes and pigments may be used. Furthermore, various fillers may be added depending on the purpose. The saponification treatment of the fatty acid cellulose ester resin may be performed by a known method. Usually, a method is used in which a fatty acid cellulose ester resin is immersed in a heated alkaline water solution. As the alkali, preferably an aqueous caustic alkali solution such as sodium hydroxide or potassium hydroxide is used. Lower alcohols, such as methanol and ethanol, and salts such as sodium sulfate can also be used as saponification promoters. In the present invention, the preferable range of the mixing ratio of the fatty acid cellulose ester resin and the saponified fatty acid cellulose ester resin to be mixed to form a pattern is as follows in terms of weight ratio: saponified fatty acid cellulose ester resin/fatty acid cellulose Ester resin = 0.1/100 to 100/100, particularly preferably 1/100 to 40/100. If the mixing ratio of the saponified fatty acid cellulose ester resin is too low, the pattern will not be effective. Also, if there is too much, the colors will be mixed throughout and the pattern will not be as effective. The combination of fatty acid cellulose ester resins is preferably the same type of fatty acid cellulose ester resins, but a combination of two or more types of different types of fatty acid cellulose ester resins may also be used. The fatty acid cellulose ester resin and the saponified fatty acid cellulose ester resin may be mixed by a known method using a tumbler, ribbon mixer, Henschel mixer, or the like. The molding conditions for obtaining a molded article according to the present invention may be the molding conditions normally used for molding the fatty acid cellulose ester resin used. According to the present invention, a screw type injection molding machine,
By using a saponified fatty acid cellulose ester resin as the mottled coloring resin, the pattern does not disappear even when using a thermoplastic resin molding machine that generates shear, such as an extrusion molding machine, and has an excellent pattern. A fatty acid cellulose resin molded article can be obtained. Alkali concentration of treatment solution during saponification treatment,
By changing the temperature and treatment time, and by changing the plasticizer content of the fatty acid cellulose ester resin to be saponified, it is possible to change the pattern from a very sharp pattern such as a veneer pattern to other patterns such as a melting pattern or a marble pattern. Even colors can be melted and even patterns can be easily created arbitrarily. The shape of the saponified fatty acid cellulose ester resin used as the mottled coloring resin can be any shape or size such as pellets, ellipses, semicircles, squares, spheres, films, and fibers. This makes it possible to obtain molded products with new and excellent patterns. The molded products of the present invention include miscellaneous goods such as combs, brush handles, shoelaces, grip-related parts such as screwdriver handles, knobs, handles, and handbag handles, accessories such as glasses, chains, net dresses, brooches, and buttons, pencil cases,
It can be applied to a variety of applications such as boxes such as cases, stationery, automobile-related parts such as automobile handles and change lever grips, other furniture knobs, and juice balls. The following examples specifically illustrate the method of manufacturing a molded article having a novel and excellent pattern according to the present invention, but the present invention is not limited to these examples. Examples 1 to 4, Comparative Example 1 Cellulose acetate resin compounds having the proportions shown in the table were mixed using a universal mixer and then dried and aged at about 80°C for 5 hours. This compound was melt-kneaded and extruded using a 30 m/m extruder at a cylinder temperature of 230°C to obtain pellet-shaped cellulose acetate resin. Next, 80 g of sodium hydroxide and 46 g of sodium sulfate were dissolved in pure water to form an aqueous solution of 2, and then heated to 40°C. The previously obtained cellulose acetate resin was immersed in this heated aqueous sodium hydroxide solution for a predetermined period of time shown in the table for saponification treatment. Thereafter, these saponified cellulose acetate resins (A) were thoroughly washed with water and then dried to remove moisture. Next, cellulose acetate resin compounds having the proportions shown in the table were mixed using a universal mixer (manufactured by Sanei Seisakusho), and then dried and aged at about 80° C. for 5 hours. This compound was melt-kneaded in a 30 m/m extruder at a cylinder temperature of 200°C to obtain pellet-shaped cellulose acetate resin. Next, the saponified cellulose acetate resin (A) and cellulose acetate resin (B) produced by the above method were mixed at a saponified cellulose acetate resin (A)/cellulose acetate resin (B) = 1/20. After mixing in a tumbler and drying at 80℃ for 3 hours, the cylinder temperature was adjusted using a screw type vertical injection molding machine (Sanjo Seiki Seisakusho SAV-30).
It was molded into a plate of 70 m/m x 40 m/m x 3 m/m at 200°C. The results for the pattern patterns of the color plates obtained in Examples 1 to 4 and Comparative Example 1 are shown in the table, and as is clear from the table, cellulose acetate resin that has not been saponified was used for mottled color. In the pattern pattern of the color plate obtained in Comparative Example 1 used, the mottled color resin and the ground color resin were almost uniformly mixed, and no pattern effect was produced at all, whereas in Example 1 , 2, 3, and 4, cellulose acetate resin molded products with various patterns could be obtained by using the saponified cellulose acetate resin as the mottled resin. In particular, a cellulose acetate resin molded product having any desired pattern from a mellow pattern to a rose pattern could be easily obtained by simply changing the saponification treatment time.

【table】

【table】

[Table] Example 5 Cellulose acetate resin colored burnt brown in the proportions shown in the table was added to an acetone solution and dissolved with stirring to obtain a solution with a concentration of 20%. Next, this mixed solution was cast onto a metal support with a thickness of 200μ
The film was formed to a thickness of . The cellulose acetate resin film thus obtained was made into a size of 6 m/m square, and 240 g of sodium hydroxide and 138 g of sodium sulfate were added to the film.
After dissolving in 138g of sodium sulfate pure water to make an aqueous solution of 2, 200c.c. of methanol was added and saponified in a solution heated to 40℃ for 6 hours, washed thoroughly with water and dried to obtain cellulose for mottled color. Acetate resin (A) was obtained. Next, a cellulose acetate resin compound colored pale yellow and transparent in the same proportion as this saponified cellulose acetate resin (A) was melt-kneaded and extruded at a cylinder temperature of 200°C by the method shown in Examples 1 to 4. A pellet-like cellulose acetate resin (B) was obtained. Next, the saponified cellulose acetate resin (A) produced by the above method and the cellulose acetate resin (B) were saponified at a mixing ratio of cellulose acetate resin (A)/cellulose acetate resin (B) = 1/30. After mixing in a tumbler and drying at 80℃ for 3 hours, a 30m/m extruder (manufactured by Takayasu Iron Works)
It was extruded into a 2 m/m sheet at a cylinder temperature of 170°C. The sheet obtained here had a pattern pattern similar to that of a shell. As is clear from this example, by saponifying cellulose acetate resin, which has the same component, the melting behavior during thermoforming can be changed to a unique state, making it extremely easy to create excellent patterns. A cellulose acetate resin molded product having the following properties could be obtained.

【table】

Claims (1)

[Claims] 1. A method for producing a fatty acid cellulose ester resin molded article, which comprises obtaining a molded article having a pattern by mixing a fatty acid cellulose ester resin and an oxidized fatty acid cellulose ester resin and heat-molding the mixture.