JPH0688349B2 - Resin pellet and resin object molding method using the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin pellet in which a surface of a pellet is uniformly coated with a filler, and a method for molding a resin object molded article using the resin pellet.

(Prior Art) A resin object is molded and processed as a resin composite material by adding another material such as rubber, another resin, an inorganic or organic filler to a raw material resin according to the purpose of the molding process.
Among these materials, many kinds of inorganic or organic fillers are used in order to improve the properties of the resin object or reduce the cost. It is known that the properties of these fillers greatly change depending on their chemical composition shape, particle size, etc., and have a great influence on the properties of the resin object which can be dispersed in the raw material resin. It is also clarified that the selection of filler is related to the properties of the raw material resin, the compounding method, the molding method, etc., and the optimum conditions exist for the shape and particle size of the filler depending on the compounding composition and molding method. ing. As described above, the selection of the filler and the blending thereof with respect to the raw material resin are important problems in the molding process of the resin object, and various studies are required to obtain the resin object in which the filler is homogeneously dispersed. The method of mixing the filler and the raw material resin varies depending on the properties of the raw material resin. Conventionally, regarding a thermoplastic resin molded product, it is generally practiced to mix a predetermined amount of a raw material resin and a filler, melt and knead the mixture to obtain pellets in which the filler is dispersed, and form a pellet to obtain a resin object. However, since the filler, especially the inorganic filler, has a physical and chemical properties that are significantly different from the raw material resin, it is difficult to uniformly disperse the filler in the raw material resin, and it tends to be localized in the raw material resin. There is. Therefore, various devices have been studied in order to uniformly disperse the inorganic filler in the raw material resin.

Also, as a method of supporting the filler on the surface of the molded object,
Conventionally, a filler is kneaded into a resin to form a molded article, and a thin film containing the filler is adhered to the surface of the molded article. Although methods such as coating the filler have been taken, when the filler is kneaded into the resin, the proportion of the filler that appears on the surface of the molded product is very small, so the effect of the filler does not appear very much. When the proportion of the kneaded filler is increased, the performance of the resin is deteriorated, and it becomes difficult to mold, and the molded product is often cracked or hardened, resulting in a molded product that is difficult to use. If the filler is expensive, the price of the molded product will be high. In order to cover the molded product with a small amount of filler, make a thin film containing a large amount of filler,
Although methods such as adhering to the surface of the molded product or coating a filler have been adopted, the adhesive product and the coated product are easily peeled off, which makes processing difficult.

(Problems to be Solved by the Present Invention) As described above, the filler, particularly the inorganic filler, has a morphology such as a shape and a particle size that greatly change as a filler, so that it is possible to obtain a uniform dispersion in the raw material resin. Thus, selection of its shape and particle size is important, and special equipment is required for its mixing. INDUSTRIAL APPLICABILITY The present invention provides a resin pellet coated with a uniform thin layer of at least one filler selected from silver, hydroxyapatite, and antibacterial zeolite on the surface by a general-purpose device and molding the same with a raw material. The present invention provides a resin object molding method by which a resin object in which a filler is uniformly dispersed can be easily obtained. Furthermore, by molding by a powder molding method such as a compression molding method, a thermoforming method, or a rotary molding method, the surface of the molded product is covered with the filler, and a molded product having a surface exhibiting the function of the filler can be easily formed. The present invention provides a method for molding a resin object, which is obtained with a small amount of filler, and the filler does not peel off from the obtained molded article, so that a resin object having a permanent function is formed.

(Means for Solving the Problem) Pellets of a raw material resin are prepared by a conventional method, and at least one filler selected from silver, hydroxyapatite, and antibacterial zeolite is adhered to the surface of the pellet particles in a uniform thin layer. A resin pellet having a surface coated with a filler is formed, and the pellet is molded into a resin object to uniformly disperse the filler, or a resin object having the surface uniformly loaded with the filler is obtained. The particle size of the raw material pellets used is not particularly limited, but when obtaining an object with a high filler content, use a relatively small particle size, and when obtaining an object with a low filler content, use a relatively large particle size pellet. As described above, it is preferable to select the particle size of the raw material pellet to be used according to the amount of the filler contained in the resin body. A high-speed airstream impact method reformer (for example, a trade name) that applies mechanical thermal energy mainly composed of impact force to particles with a mixture of raw material pellets and a predetermined amount of filler to immobilize and film-forms : Hybridization system
・ Nara Machinery Co., Ltd.) and coat the raw material pellets with filler. The ratio of the raw material pellet and the filler varies depending on the coating amount of the filler. The raw material pellet to be used, the shape of the filler, and the particle diameter are not particularly limited, but the raw material pellet is desired to be as spherical as possible in order to coat the filler uniformly, and the filler is 1 / th of the particle diameter of the raw material pellet. 10 or less is good.

It is desirable that the particle size of the filler used is as uniform and fine as possible, and it is 1/10 of the particle size of the raw material pellets used.
Adjust as follows. The speed of the sprayed filler is adjusted in relation to the rotational speed of the pan, but it is not particularly limited. The amount of the filler to be sprayed varies depending on the particle size of the raw material pellet, but the amount of the filler used is at least 0.1 or more based on the raw material resin pellet used. After spraying the filler, continue blowing the inert gas while rotating the pan, completely distill off the low boiling point solvent, take out the treated product, and screen the product with the filler to coat the filler. Get Further, when the coated resin pellet is molded by the following method, it is possible to increase the coating amount and easily coat a material which is difficult to coat. When coating a filler on a raw material resin pellet, if the coating process is performed by coexisting with resin beads and powder with the same type of resin as the raw material and a particle size smaller than the raw resin pellet, the filler will be the raw resin pellet. In addition to being coated on coexisting small particle size or powder resin, this coated small particle size or powder resin is coated on the raw material resin pellet, so only the raw material resin pellet is coated with the filler. Compared with the case, the coating amount can be easily increased. In this case, the small particle size or the resin particle size of the powder is preferably 1/10 or less of the particle size of the raw resin pellet, and the particle size of the filler is preferably smaller than the small particle size or the resin particle size of the powder. Further, the small particle size to be added and the resin amount of the powder are changed depending on the amount of the filler to be coated, the particle size, the particle size of the raw resin pellet. If it is difficult to coat the filler on the raw material resin pellets, a resin that is easy to coat the filler is selected as a resin having a small particle size or powder, and the filler is easily coated on the resin having this small particle size or powder. Since the raw material resin pellets are coated with the filler through the coated resin, the raw material resin pellets can be easily coated with the filler.

This pellet has a property that it is like a ordered mixture by depositing a filler on the surface of the pellet in a uniform thin layer. When using a slurry for spraying the filler, if a water-containing solvent is used as the low boiling point solvent, adhesion of the fillers will occur and the amount of the filler adhered will increase with the water content, so it is also possible to use a water-containing solvent slurry if necessary. Yes, particularly preferable when molding a resin object having a high filler content. It is possible to obtain a resin object in which the resin pellets obtained by uniformly coating the obtained filler on the surface are molded and processed by a conventional method to uniformly disperse the filler, or on the surface of the molded product. .

(Function) A filler-coated resin pellet obtained by treating a mixture of a raw pellet and a filler with a high-speed air stream impact modifier, or an inert gas having a plasticizing temperature of the raw pellet. Heat to melt only its surface,
The filler-coated resin pellet obtained by adhering the filler to the melting surface allows the filler coating amount on the raw material pellet to be arbitrarily selected, and the resin pellet coated uniformly with filler can be obtained as the raw material pellet or the material of the filler. Anything can be used. By molding the filler-coated resin pellets thus obtained by a conventional method, it is possible to easily obtain a resin object in which the filler is homogeneously dispersed inside, and compression molding of these resin pellets in which the pellets do not flow too much. The resin object molded by powder molding method such as thermoforming method, thermoforming method, rotational molding method, etc. has the function of the filler permanently because the filler is uniformly supported on the surface of the object and the filler does not separate from the surface. It is possible to obtain a resin object having a surface showing.

Hereinafter, the present invention will be specifically described with reference to examples.

Example 1. 390 g of polyethylene beads having a particle diameter of about 1 mm and 10 g of hydroxyapatite having a diameter of about 1 μm were put into a mixer having a diameter of 20 cm,
Run at 1,000 rpm for 5 minutes and remove the mixture. 200g of this mixture was put in a high-speed air stream impact reformer with a diameter of 25 cm,
After operating at 800 rpm for 2 minutes, the contents were taken out to obtain beads in which polyethylene beads were coated with hydroxyapatite. As a result of observing the beads with an electron microscope, it was confirmed that hydroxyapatite was attached to the surface of the beads in a uniform thin layer. The results of electron microscopic observation after the beads were washed off with water were also the same.

Example 2. The beads obtained in Example 1 were thermoformed at 130 ° C to prepare a porous sheet. Electron microscope observation of the molded product showed that the hydroxyapatite adhered to the surface of the molded product almost uniformly.

Example 3. 360 g of polyethylene beads having a particle size of about 500 μm and 40 g of tribasic calcium phosphate of 200 mesh pass are put into a mixer having a diameter of 20 cm, operated at 1,000 rpm for 3 minutes, and the mixture is taken out.
200 g of this mixture was put in a high-speed air impact modifier with a diameter of 25 cm, and after operating at 6,000 rpm for 2 minutes, the contents were taken out to obtain beads in which polyethylene beads were coated with tricalcium phosphate. This was compression molded at 120 ° C. and 20 kg / cm ² to prepare a sheet. Electron microscopic observation of the molded product showed that tricalcium phosphate was almost uniformly attached to the surface of the molded product.

Example 4. 100g of nylon beads with a particle size of about 100μm and 100g of silver powder with a particle size of about 1μm or less were put into a high speed impact reformer and 8,000rpm.
After operating for 3 minutes, the contents were taken out to obtain coated beads. As a result of observing the beads with an electron microscope, it was confirmed that silver adhered to the surface of the beads in a uniform thin layer.
The results of electron microscopic observation after the beads were washed off with water were also the same. Also, beads at 220 ℃, 30kg /
A sheet was prepared by compression molding at cm ² . Electron microscopic observation of the molded product showed that silver was almost uniformly attached to the surface of the molded product. Also, this nylon sheet became a conductive sheet.

Example 5. 380 g of polyethylene beads having a particle size of about 1 mm and 20 g of antibacterial zeolite having a particle size of 10 μm or less are put into a mixer having a diameter of 20 cm,
Run at 1,000 rpm for 5 minutes and remove the mixture. 150 g of this mixture was put into a high-speed air stream impact reformer with a diameter of 25 cm,
After operating at 000 rpm for 1 minute, the contents were taken out to obtain beads in which polyethylene beads were coated with antibacterial zeolite. This was compression-molded at 120 ° C. and 1 kg / cm ² to prepare a porous sheet. Electron microscopic observation of the molded product showed that the antibacterial zeolite adhered to the surface of the molded product almost uniformly.

Example 6 The polyethylene beads of Example 5 were changed to acrylic beads and a coating operation was carried out by a high-speed air current impact modifier to obtain acrylic beads coated with antibacterial zeolite. This was thermoformed at 140 ° C. to form a porous sheet. Electron microscopic observation of the molded product showed that the antibacterial zeolite adhered to the surface of the molded product almost uniformly.

Example 7 The polyethylene beads of Example 5 were replaced with polystyrene beads, and a coating operation was performed by a high-speed air current impact modifier to obtain polystyrene beads coated with antibacterial zeolite. This was injection-molded at 180 ° C. and 30 kg / cm ² to prepare a porous molded body. Electron microscopic observation of this molded product showed that the antibacterial zeolite adhered to the surface of the molded product almost uniformly.

Example 8. Polyethylene beads having a particle size of about 1 mm were replaced with expandable polystyrene beads having a particle size of 0.5 to 2 mm, and antibacterial zeolite and a deodorant were coated by a high-speed impact modifier to obtain coated beads. This was put into a mold and heated to 120 ° C. to obtain a foamed molded article having antibacterial and deodorizing effects.

(Effects of the Invention) At least one filler selected from the group consisting of silver, hydroxyapatite and antibacterial zeolite of predetermined particles was uniformly adhered to the surface of the raw material pellet of the predetermined particles by a high-speed air current impact modifier. Resin pellets or raw material pellets and filler are treated with a pan to form a resin pellet with the filler evenly attached to the surface. It is possible to obtain a resin object in which the filler is homogeneously dispersed in any amount of filler regardless of the nature of the filler, and it is possible to use a powder molding method such as compression molding, thermoforming or rotational molding as a molding method. When molded, the filler is uniformly supported on the surface of the molded product, and the supported filler is not peeled off, so that the function of the filler is achieved. Permanently retained on the surface of a shaped object. Therefore, a resin object suitable for use such as a conductive sheet, an antibacterial molded body, a porous sheet, etc. can be obtained by a simple method.

Claims (2)

[Claims] 1. The surface of the pellet is uniformly coated with at least one filler selected from silver, hydroxyapatite, and antibacterial zeolite using a high-speed air impact modifier. Resin pellets. 2. A resin pellet in which at least one filler selected from silver, hydroxyapatite, and antibacterial zeolite is uniformly coated on the surface of the pellet using a high-speed impact modifier, and resin pellets are used. Resin object molding method for molding resin objects.