TW201516076A - Method for producing fine powder - Google Patents

Abstract

The objective of the present invention is to provide a method for producing a fine polymer powder with which it is possible to easily produce a scaly powder that is thin and has excellent thickness uniformity. This objective is achieved by: a fine powder production method comprising a step for alternately laminating two types of resins (resin A and resin B) and preparing a multi-layer laminate including at least 16 layers, a step for reducing the laminate into a fine powder by pulverization, and a (peeling) step for dividing the interface between the laminated layers; and particularly a fine powder production method in which the pulverization step and the division step are integrated.

Description

Method for producing micro powder

The present invention relates to a method for producing a scaly micropowder having a particle diameter of 1 to 300 μm and a thickness of 0.1 to 50 μm.

Various types of powders are used for cosmetics and the like, for example, powdered clay minerals and/or color materials (for example, dyes, pigments). Clay minerals are mainly represented by talc and mica. Since these powders have been used for a long time as a cosmetic material, such as coating power, ductility, and adhesion, they have been used for a long time. However, due to human sebum and oils contained in cosmetics, it is easy to make the brightness of the fine powder. The chroma is lowered, so it is easy to cause the blackening of the powder or the dullness of the color. On the other hand, the fine powder of the organic substance is softer and softer than the inorganic fine powder. Further, the scaly fine powder is superior in ductility to the spherical clay mineral (Patent Document 1 and Patent Document 2). For the above reasons, it is desirable to provide a scaly fine powder suitable for use as an organic substance, particularly a polymer, for use as a cosmetic or the like.

As a method for producing a scaly fine powder, a liquid layer on a liquid layer which is a liquid at a normal temperature is proposed, and a polymer solution in which a polymer is dissolved in an organic solvent is developed in a film form, and a film is formed by desolvation. And a method of pulverizing the film (Patent Document 2). However, in this method, the drying step is necessary, the productivity is low, and due to the extensive use of organic Solvents and environmental or operator impact have become a problem.

Further, a method of dropping fine droplets of a polymer solution onto a flat plate and curing it has been proposed (Patent Document 3). However, in this method, since it is difficult to cut into a fine powder having a desired thickness, or a film or the like is not easily peeled off from the substrate, it is not easy to obtain a fine powder suitable as a flaky polymer used for cosmetics or the like.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3963635

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2002-308996

[Patent Document 3] JP-A-63-117040

In the conventional production method, it is difficult to pulverize into a scaly fine powder having a desired thickness, or it is difficult to obtain a fine powder having a uniform thickness, and even if a film for producing a fine powder is obtained, productivity is low, and Drainage treatment is required and therefore cannot be easily obtained.

The present invention has been made in view of the above problems, and an object thereof is to provide a method for producing a fine powder of a polymer, wherein the production of a film for producing a fine powder is easy, and a thin thickness and superior thickness uniformity can be easily obtained. A flaky powder; and a micropowder which is useful as a polymer powder for cosmetics or an industrial powder such as a color material.

The method for producing the polymer micropowder of the present invention is provided The following steps are a method for producing a fine powder: a step of alternately laminating two kinds of resins (resin A and resin B) to form a multi-layered body having a laminated number of 16 or more layers; a step of finely pulverizing by pulverization; and dividing The step of laminating the interface (peeling). When the production amount of the fine powder is considered, the number of layers must be 16 or more, preferably 32 or more. Here, the order of the step of finely pulverizing by pulverization and the step of dividing the interface (peeling) of the deposited layers may be front and rear, or two steps may be simultaneously performed.

The case of making a micro-powder of a single material by The resin is formed into a multi-layered body made of a water-soluble resin, and after dissolving the water-soluble material after the pulverization step, a fine powder of a single material can be obtained. Further, a powder of a single material can be obtained by pulverizing the water-soluble material before the pulverization step.

The micropowder of the present invention has an average thickness (t) of 0.1 μm or more. In the range of 50 μm or less, the particle diameter (d) represented by the center value of the particle diameter distribution is in the range of 1 μm or more to 300 μm or less, and the aspect ratio (d/t) of the ratio of the particle diameter (d) to the thickness (t) ) is 6 or more and 300 or less.

From the point of view of the separation of the laminate interface, as a tree for layering The fat is preferably polymethyl methacrylate resin (PMMA) and polystyrene resin (PS), polymethyl methacrylate resin (PMMA) and alicyclic olefin resin (COP) or alicyclic olefin. A copolymer (COC), or a combination of a polymethyl methacrylate resin (PMMA) and a polyamide resin (PA).

According to the present invention, it is possible to provide a thickness which can be easily obtained A method for producing a polymer micropowder of a flaky powder having a small thickness and uniformity of thickness, and a fine powder of a polymer which is useful as an industrial powder such as a cosmetic powder or a color material.

D1‧‧‧ particle size

T1‧‧‧ thickness

Fig. 1 is a process chart showing an example of a method for producing a laminate according to the present invention.

Fig. 2 is a laser micrograph showing an example of a cross-sectional structure of a laminated film produced in Example 1 of the present invention.

Fig. 3 is an electron micrograph of a laminated film pulverized product produced in Example 1 of the present invention.

Fig. 4 is a view showing an example of the measurement result of the particle size distribution of the fine powder produced in Example 1 of the present invention.

Fig. 5 is an electron micrograph of the PMMA/PC film pulverized product shown in Reference Example 2.

Fig. 6 is a perspective view showing an example of the fine powder of the present invention.

[Formation of the Invention] <Method of Manufacturing Laminates>

As shown in Fig. 1, the method for producing a laminate of the present invention is produced by laminating at least two molten resins into two kinds of resins called feed blocks, and is formed in the horizontal direction and adjacent to each other. Laminated flow (2 types of 2 layers or 2 types of 3 layers); 2 steps left and right in step 2; steps of expanding in the width direction and steps of compressing in the thickness direction are simultaneously performed in step 3; The respective layers overlap; thereby making 17 layers of alternating laminates. By repeating the steps 2 to 4 in one group, the number of layers can be increased. As described above, starting from two kinds of three-layer laminar flow, one group can produce five layers, two groups can produce nine layers, and three groups can produce 17 layers of laminated bodies, and the number of layers can be 2 ^{(N+1). )} +1 (here, N is the number of groups of steps 2 to 4). Starting from two kinds of two-layer laminar flow, one group can produce four layers, two groups can produce eight layers, and three groups can produce 16 layers of laminated bodies, and the number of layers can be 2 ^(N+1). , N is the number of steps 2 to 4).

After the steps of forming the laminated body, the resin C is laminated on the outermost layer side, and then formed into a film shape in the lateral direction by a die. Here, the outermost layer (resin C) is used to prevent the structure of the laminate (B/A/...A/B) from collapsing inside the film die and to laminate. The thickness of each layer formed into a film shape can be appropriately determined by blending the thickness of the particles obtained by the pulverization step described later.

As a method of efficiently producing a film, a melt extrusion method can be mentioned. However, in the case where a single-layer film having a thickness of 1 to 50 μm is produced by the same method, the strength of the material is insufficient and there is a problem that the film is broken during the step of drawing or winding, and it is difficult to manufacture stably. The film thickness which can be stably produced is empirically 50 to 60 μm or more. The resulting film can also be stretched thereafter.

Then, a resin having a low adhesion property is produced by a melt extrusion method to produce a multilayer film having a thin thickness and alternately laminated, and the layer is peeled off while being pulverized, whereby a scaly fine powder of a film can be produced.

The obtained multilayer film was pulverized by a pulverizer to prepare a fine powder. Examples of the pulverization method include dry pulverization and wet pulverization. , frozen crushing, etc. Examples of the pulverizer include a hammer mill pulverizer, a pin crusher, an impact pulverizer, a jet mill crusher, a ball mill pulverizer, an impact pulverizer, and an air flow pulverizer. Machine, jet mill, etc. Among them, the dry pulverization method is preferred because it does not require a drying step.

In the pulverizing step, the pulverizing device may be due to frictional heat, etc. In addition, as a high-temperature, a liquefied gas such as a liquefied carbon dioxide gas or a liquid nitrogen gas is used as a coolant, and the multilayer film is cooled and pulverized while being cooled, or a cooling medium is introduced into the apparatus to be cooled. Thereby, even if the shearing heat, the frictional heat, or the like at the time of pulverization does not cause the multilayer film to be melt-bonded or the like, the film can be finely pulverized without impairing the thickness of the film. As a micro-pulverization method, in consideration of the production cost, a method in which a cooling medium is introduced into the apparatus and cooled is preferred.

In the pulverization process, it can be divided into the surface of cutting solid materials. The surface is pulverized and pulverized in a volume which gradually becomes large and the solid is gradually broken. In reality, it can be considered that the pulverization is carried out under combined surface pulverization and volume pulverization. Resins with alternating layers of low affinity to each other may seem to be easy to peel off at first glance. The pulverization force occurring in the pulverization process of the laminated film is an inducement, and the peeling between the layers is also promoted.

As a resin having low affinity, for example, with polymethacryl Examples of the acid methyl ester resin combination include a polystyrene resin (PS), an alicyclic olefin resin (COP), an alicyclic olefin copolymer (COC), and a polyamide resin (PA). Alternating laminated films are likely to cause interlayer peeling.

Figure 6 shows the magnifying powder obtained by the above method. An oblique view of the appearance of an example. In addition to the narrow "plate shape", the fine powder includes polymer particles of a shape such as "flaky" or "scaly" which are produced according to the method of pulverization.

When a water-soluble resin is used for one of the resins, Exceval (registered trademark of Kuraray Co., Ltd.) or an aqueous PVA resin containing water in a polyvinyl alcohol resin. After the obtained multilayer film is pulverized, the water-soluble resin component is completely eluted by treatment in hot water at 98 ° C for 60 minutes, and a water-insoluble resin component can be obtained (processing conditions are as follows: Patent Application No.: Japanese Patent Application No. 11- 247061, invention name: easy to split polyamide type composite fiber).

In the fine powder used in the present invention, generally, the sixth The thickness shown by t1 in the figure, that is, the thickness in one powder can be adjusted according to the discharge amount, the drawing speed, and the pulverization conditions at the time of extrusion molding. Further, the particle diameter shown by d1 in the figure can also be adjusted in accordance with the degree of pulverization obtained. In addition, the thickness is a thickness (t) representing t1 based on the arithmetic mean of the individual t1 obtained by observation with an electron microscope, and it is difficult to individually measure d1 for the particle diameter, and is obtained by the light diffraction method. The particle size distribution center value is set to represent the particle diameter (d) of d1. Further, by the above adjustment, various aspect ratio (d/t) of the plate-like polymer powder can be obtained.

The micropowder of the present invention is blended into a cosmetic material In the case of the fine powder, the thickness (t) is preferably from 0.1 μm to 50 μm, more preferably from about 0.1 μm to 30 μm, particularly preferably from 0.5 μm to 20 μm. Further, the fine powder has a particle diameter of from 1 μm to 300 μm, more preferably from 1 μm to 200 μm. Further, the aspect ratio (d/t) of the fine powder is about 6 or more and 300 or less, more preferably about 10 or more and 200 or less. . In general, adhesion is considered to depend on the thickness of the fine powder, and the thinner it is, the easier it is to adhere. If the thickness of the fine powder is too thin, there is a tendency that the dispersibility or the ductility is poor, and it is not preferable because it aggregates or condenses in the pores or the furrow. Further, when the thickness of the powder is too thick, the ductility is impaired, and the adhesion to the skin or the adhesion between the particles is lowered, which is not preferable.

If the above range is used as a blending material In the case of fine powder, it is thin and large in transparency, and it is excellent in transparency. It can obtain excellent dispersibility in cosmetic materials, soft touch and good slidability, adhesion to skin, and no color over time. It is dull and the transparency of the coating film is continuous, and the high quality of the makeup effect is good.

The acrylic resin used in the present invention means methacrylic acid A copolymer of a single polymer of methyl ester or a monomer mixture containing methyl methacrylate as a main component and containing other copolymerized monomers is preferably used in a polymerization degree of 3,000 or less. Further, in the case where transparency is required, it is preferably a polymerization degree of about 300 to 1,000, more preferably a polymerization degree of 400 to 600, and a melt flow rate of 25 to 34 g/10 minutes (200 ° C - 3.8). Kg).

As a monomer copolymerized with methyl methacrylate, For example, acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; ethyl methacrylate, butyl methacrylate, and 2-hydroxy methacrylate may be mentioned. Ethyl acrylate, glycidyl methacrylate, methacrylate such as cyclohexyl methacrylate; acetate such as vinyl acetate; aromatic vinyl compound such as styrene or α-methyl styrene; Maleic anhydride, maleic acid mono- and dialkyl esters, and N-phenyl maleimide, such as maleimide, Acrylic acid, methacrylic acid, metal acrylate, metal methacrylate, and the like. These may be used alone or in combination, and the copolymerization ratio with methyl methacrylate is usually preferably in the range of about 1 to 30% by weight.

The styrene resin is composed of a styrene monomer unit. Examples of the styrene-based monomer include styrene, α-methylstyrene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, and 4-dodecylbenzene. Ethylene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, and the like. These can be used in combination of two or more types. Among these, a styrene resin styrene resin is preferable.

Further, the styrene resin may also contain a rubbery polymer. Rubber-containing polystyrene resin. Here, the rubber-based polymer-based glass transition temperature is preferably 0° C. or lower, more preferably -20° C. or lower, and preferred examples thereof include polybutadiene and a styrene-butadiene copolymer. Up to 30% by weight of a styrene-butadiene copolymer of a lower alkyl (meth)acrylate, a diene rubber such as polyisoprene or polychloroprene. Examples of other suitable rubbery polymers include C1 to C8 alkyl acrylates, and particularly alkyl acrylate rubbers mainly composed of ethyl acrylate, butyl ester and ethylcyclohexyl ester. The alkyl acrylate rubber may copolymerize up to 30% by weight of vinyl acetate, methyl methacrylate, styrene, acrylonitrile, vinyl ether, etc., and may further copolymerize less than 5% by weight of alkylene glycol ( A crosslinkable unsaturated monomer such as methyl acrylate, divinyl benzene or triallyl isocyanurate.

Preferred examples of the styrene resin include a specific example. Polystyrene, rubber-containing polystyrene, acrylonitrile-styrene copolymer, rubber-containing acrylonitrile-styrene copolymer, styrene-methacrylic acid Ester copolymer, rubber-containing styrene-methyl methacrylate copolymer, styrene-butyl acrylate copolymer, rubber-containing styrene-butyl acrylate copolymer, styrene-butadiene block copolymer, A styrene-diene block copolymer of a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, and the like thereof and a hydride thereof. These resins may be used alone or in combination of two or more. Among these, from the viewpoint of various physical property equalization surfaces, polystyrene and a rubber-containing polystyrene resin are preferable.

As the alicyclic polyolefin resin, JSR (preferably) can be used. Arton (registered trademark), Zeonor (registered trademark) and Zeonex of Zeon (Japan), Apel (registered trademark) of Mitsui Chemicals Co., Ltd., Topas of POLYPLASTICS (share), etc.

The polyamine-based resin can use a lining of 3 or more rings. An amine, a polymerizable ω-amino acid, a polyamine resin obtained by polycondensation of a dibasic acid with a diamine or the like. Specifically, ε-caprolactam, aminocaproic acid, heptanolactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid, α-pyrrolidone, α a polymer such as piperidone or the like; a diamine such as hexamethylenediamine, 9-methylenediamine, undecylenediamine, dodecylenediamine or meta-xylenediamine A polymer or copolymer obtained by polycondensation of a dicarboxylic acid such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecanedioic acid or glutaric acid, for example, resistant to Lun 4, 6, 7, 8, 11, 12, 6‧6, 6‧10, 6‧11, 6‧12, 6T, 6/6‧6, 6/12, 6/6T, 6I/6T, etc.

Among them, from the surface of the heat and mechanical properties of the obtained film, Nylon 6 Nylon 6/6‧6 copolymer resin is particularly suitable.

The above resins used in the present invention may be used individually or individually. It is also possible to mix two or more types and use it.

[Examples] <Method for producing scaly micro powder>

A twin-pump impeller (Twin Impeller) was used to carry out a dry air pulverizer (Dry Burst model DB-180W, manufactured by Sugino Machine). The pulverization method is carried out by adjusting the number of revolutions of the impeller on the feed side of the material and the number of revolutions of the impeller on the material discharge side. The pulverization conditions are shown in Table 1.

<Measurement of the shape of scaly fine powder> [Measurement of particle size (d)]

The particle diameter was measured by using a laser diffraction type particle size distribution measuring apparatus (Model: LA-910) manufactured by Horiba, Ltd., by pulverizing the obtained fine powder. In the present invention, the particle diameter is set to the particle diameter (d) at the center value (D50) of the particle diameter distribution obtained by the particle size distribution measuring device.

[Measurement of average thickness (t)]

The thickness of the fine powder obtained by the pulverization was measured using a scanning electron microscope (Model: S-2150) manufactured by Hitachi. The thickness measurement system is an average value of the measurement results of five randomly selected powders.

<Example 1>

As a resin used for the material A, polymethyl methacrylate (PMMA resin, Parapet (registered trademark) HR-L, manufactured by Kuraray) was used as the resin A, and polystyrene (PS resin, MT5D/G100C=50/50wt). %, made by Toyo Styrol) as Resin B. Each of the resin A and the resin B was made into a molten state at a temperature of 230 ° C by a uniaxial extruder (PSV 22 mm: manufactured by PLAENGI Co., Ltd.), and was measured and introduced by a gear pump so that the discharge ratio became resin A/resin B = 1/5. Step 1 of the mold. A 17-layer laminate was produced by repeating three sets of steps 2 to 4. Next, low-density polyethylene (LDPE resin, Novatec LC600, manufactured by Japan Polyethylene) was coated on the outermost layer of the laminate, and then spun through a 300 mm-wide film die (gap of the die: about 1 mm). Three metal mirror rolls having a temperature of 6 m/min and a temperature of 40 ° C were cooled and a total of 19 layers of the film were produced. The LDPE resin layer of the obtained film was placed in a pulverizer by a peeling machine of 30 g, and a fine powder was produced under the conditions of a number of revolutions of 8000 × 9000 min ^-1 (in × ×) and a treatment time of 2 minutes and 30 seconds. A laser microscope photograph of the laminate before pulverization is shown in Fig. 2. A scanning electron micrograph of the pulverized product is shown in Fig. 3. The results of measuring the particle size of the fine powder are shown in Fig. 4.

<Example 2>

A fine powder was produced under the same conditions as in Example 1 except for the amount of the resin, the number of revolutions, and the treatment time. The fine powder was produced under the conditions of an input amount of 30 g, a number of revolutions of 8000 × 10000 min ^-1 (IN × OUT), and a treatment time of 2 minutes and 50 seconds.

<Example 3>

As the resin used in the material A, polymethyl methacrylate (PMMA resin, Parapet (registered trademark) HR-L, manufactured by Kuraray) was used as the resin A, and a cycloolefin copolymer (COP resin, Topas 6013S, manufactured by Ticona) was used as the resin A. Resin B. Each of the resin A and the resin B was made into a molten state at a temperature of 250 ° C by a uniaxial extruder (PSV 22 mm: manufactured by PLAENGI Co., Ltd.), and was measured and introduced by a gear pump so that the discharge ratio became resin A/resin B = 1/5. Step 1 of the mold. Made by repeating 3 sets of steps 2 to 4 A layer of 17 layers.

Next, low-density polyethylene (LDPE resin, Novatec LC600, manufactured by Japan Polyethylene) was coated on the outermost layer of the laminate, and then spun through a 300 mm-wide film die (gap of the die: about 1 mm). Three metal mirror rolls having a temperature of 6 m/min and a temperature of 40 ° C were cooled and a total of 19 layers of the film were produced.

The LDPE resin layer of the obtained film was placed in a pulverizer by a peeling machine of 30 g, and a fine powder was produced under the conditions of a number of revolutions of 8000 × 9000 min ^-1 (IN × OUT) and a treatment time of 2 minutes and 30 seconds.

<Example 4>

The resin used for the material A is a polymethyl methacrylate (PMMA resin, Parapet (registered trademark) GF, manufactured by Kuraray), and a polymethyl methacrylate-polystyrene copolymer resin (MS resin, Estyrene MS‧200, Nippon Steel & Sumitomo Chemical Co., Ltd.) as Resin B. Each of the resin A and the resin B was made into a molten state at a temperature of 230 ° C by a uniaxial extruder (PSV 22 mm: manufactured by PLAENGI Co., Ltd.), and was measured and introduced by a gear pump so that the discharge ratio became resin A/resin B = 4/1. Step 1 of the mold. A 17-layer laminate was produced by repeating three sets of steps 2 to 4. Next, low-density polyethylene (LDPE resin, Novatec LC600, manufactured by Japan Polyethylene) was coated on the outermost layer of the laminate, and the film was discharged through a 300 mm-thick film die (gap of the die: about 1 mm). A three-metal mirror roll having a speed of 3.6 m/min and a temperature of 40 ° C was cooled to prepare a film of a total of 19 layers.

The LDPE resin layer of the obtained film was placed in a pulverizer by 268 g of a peeling, and a fine powder was produced under the conditions of a number of revolutions of 8000 × 10000 min ^-1 (IN × OUT) and a treatment time of 12 minutes and 12 seconds.

<Reference Example 1>

As the resin used in the material A, polymethyl methacrylate (PMMA resin, Parapet (registered trademark) GF, manufactured by Kuraray) was used as the resin A, and polypropylene (PP resin, Novatec MA3, manufactured by Japan Polypropylene) was used as the resin B. . Each of the resin A and the resin B was made into a molten state at a temperature of 230 ° C by a uniaxial extruder (PSV 22 mm: manufactured by PLAENGI Co., Ltd.), and was measured and introduced by a gear pump so that the discharge ratio became resin A/resin B = 1/2. Step 1 of the mold. A 17-layer laminate was produced by repeating three sets of steps 2 to 4. Next, low-density polyethylene (LDPE resin, Novatec LC600, manufactured by Japan Polyethylene) was coated on the outermost layer of the laminate, and the film was discharged through a 300 mm-thick film die (gap of the die: about 1 mm). Three metal mirror rolls having a temperature of 6 m/min and a temperature control of 40 ° C were cooled to prepare a film of a total of 19 layers. 30 g was placed in a pulverizer, and fine powder was produced under the conditions of a number of revolutions of 8000 × 9000 min ^-1 (IN × OUT) and a treatment time of 2 minutes and 30 seconds. As a result of observing the layer peeling state of the ground product by a scanning electron microscope photograph, the melt of the polypropylene and the ground product of polymethyl methacrylate were mixed, and a good fine powder could not be obtained.

<Reference Example 2>

As the resin used in the material A, polymethyl methacrylate (PMMA resin, Parapet (registered trademark) GF, manufactured by Kuraray) was used as the resin A, and polycarbonate (PC resin, Lexan 121R, manufactured by SABIC) was used as the resin B. . Each of the resin A and the resin B was made into a molten state at a temperature of 250 ° C by a uniaxial extruder (PSV 22 mm: manufactured by PLAENGI Co., Ltd.), and was measured and introduced by a gear pump so that the discharge ratio became resin A/resin B = 1/2. Step 1 of the mold. A 17-layer laminate was produced by repeating three sets of steps 2 to 4. Next, low-density polyethylene (LDPE resin, Novatec LC600, manufactured by Japan Polyethylene) was coated on the outermost layer of the laminate, and the film was discharged through a 300 mm-thick film die (gap of the die: about 1 mm). Three metal mirror rolls having a temperature of 6 m/min and a temperature control of 40 ° C were cooled to prepare a film of a total of 19 layers. 30 g was placed in a pulverizer, and fine powder was produced under the conditions of a number of revolutions of 8000 × 9000 min ^-1 (IN × OUT) and a treatment time of 2 minutes and 30 seconds. As a result of observing the layer peeling state of the pulverized product by a scanning electron microscope photograph, although some of the peeling was observed, most of the peeling was not observed. The observation result of the pulverized product is shown in Fig. 5.

<Reference Example 3>

As a resin used for the material A, polymethyl methacrylate (PMMA resin, Parapet (registered trademark) HR-L, manufactured by Kuraray) was used as the resin A, and amorphous polyethylene terephthalate (PET resin) was used. SKYGREEN PETG S2008 SK Chemicals) as Resin B. Each of the resin A and the resin B was made into a molten state at a temperature of 230 ° C by a uniaxial extruder (PSV 22 mm: manufactured by PLAENGI Co., Ltd.), and was measured and introduced by a gear pump so that the discharge ratio became resin A/resin B = 1/1. Step 1 of the mold. A 17-layer laminate was produced by repeating three sets of steps 2 to 4. Next, low-density polyethylene (LDPE resin, Novatec LC600, manufactured by Japan Polyethylene) was coated on the outermost layer of the laminate, and the film was discharged through a 300 mm-thick film die (gap of the die: about 1 mm). 3 metal mirror rollers with a speed of 6m/min and a temperature control of 40°C The film was cooled to produce a film of a total of 19 layers.

30 g was placed in a pulverizer, and fine powder was produced under the conditions of a number of revolutions of 8000 × 9000 min ^-1 (IN × OUT) and a treatment time of 3 minutes and 16 seconds. As a result of observing the layer peeling state of the pulverized product by a scanning electron microscope photograph, although some of the peeling was observed, most of the peeling was not observed.

<Example 5>

As a resin used for the material A, polymethyl methacrylate (PMMA resin, Parapet (registered trademark) GF, manufactured by Kuraray) and polystyrene (PS resin, MT5D/G100C=50) were mixed at a weight ratio of 20/80. As the resin A, the resin used in the material B was made of polymethyl methacrylate (PMMA resin, Parapet (registered trademark) GH-S, manufactured by Kuraray) as the resin B. Each of the resin A and the resin B was made into a molten state at a temperature of 230 ° C by a uniaxial extruder (PSV 22 mm: manufactured by PLAENGI Co., Ltd.), and was measured and introduced by a gear pump so that the discharge ratio became resin A/resin B = 4/1. Step 1 of the mold. A 17-layer laminate was produced by repeating three sets of steps 2 to 4.

Next, low-density polyethylene (LDPE resin, Novatec LC600, manufactured by Japan Polyethylene) was coated on the outermost layer of the laminate, and the film was discharged through a 300 mm-thick film die (gap of the die: about 1 mm). A three-metal mirror roll having a speed of 3.6 m/min and a temperature of 40 ° C was cooled to prepare a film of a total of 19 layers. The LDPE resin layer of the obtained film was placed in a pulverizer by a peeling machine of 30 g, and a fine powder was produced under the conditions of a number of revolutions of 8000 × 9000 min ^-1 (IN × OUT) and a treatment time of 2 minutes and 30 seconds.

<Reference Example 4>

As a resin used for the material A, polymethyl methacrylate (PMMA resin, Parapet (registered trademark) EH, manufactured by Kuraray) and polycarbonate (PC resin, Lexan 121R, SABIC) were mixed at a weight ratio of 20/80. As the resin A, polymethyl methacrylate (PMMA resin, Parapet (registered trademark) GF, manufactured by Kuraray) was used as the resin B. Each of the resin A and the resin B was made into a molten state at a temperature of 250 ° C by a uniaxial extruder (PSV 22 mm: manufactured by PLAENGI Co., Ltd.), and was measured and introduced by a gear pump so that the discharge ratio became resin A/resin B = 4/1. Step 1 of the mold. A 17-layer laminate was produced by repeating three sets of steps 2 to 4. Next, low-density polyethylene (LDPE resin, Novatec LC600, manufactured by Japan Polyethylene) was coated on the outermost layer of the laminate, and the film was discharged through a 300 mm-thick film die (gap of the die: about 1 mm). A three-metal mirror roll having a speed of 3.6 m/min and a temperature of 40 ° C was cooled to prepare a film of a total of 19 layers.

The LDPE resin layer of the obtained film was placed in a pulverizer by a peeling machine of 30 g, and a fine powder was produced under the conditions of a number of revolutions of 8000 × 9000 min ^-1 (IN × OUT) and a treatment time of 2 minutes and 30 seconds. As a result of observing the layer peeling state of the pulverized product by a scanning electron microscope photograph, although some of the peeling was observed, most of the peeling was not observed.

The results of the above examples and reference examples are shown in Table 1. Further, the combination of the resins of Reference Examples 1 to 4 was not separable under the test conditions of the reference example, but the possibility of division was possible if the conditions were appropriate. Therefore, the present invention does not exclude the combination of the resins of the reference examples.

<Example 6>

As a resin used for the material A, polymethyl methacrylate is used. (PMMA resin, Parapet (registered trademark) GF, manufactured by Kuraray), a water-soluble resin (Exceval (registered trademark) CP-410, manufactured by Kuraray) was used as the resin B. Each of the resin A and the resin B was made into a molten state at a temperature of 220 ° C by a uniaxial extruder (PSV 22 mm: manufactured by PLAENGI Co., Ltd.), and was measured and introduced by a gear pump so that the discharge ratio became resin A/resin B = 1/5. Step 1 of the mold. A 17-layer laminate was produced by repeating three sets of steps 2 to 4. Next, low-density polyethylene (LDPE resin, Novatec LC701, manufactured by Japan Polyethylene) was coated on the outermost layer of the laminate, and then spun through a 300 mm-thick film die (gap of the die: about 1 mm). Three metal mirror rolls having a temperature of 6 mm/min and a temperature of 40 ° C were cooled and a total of 19 layers of the film were produced.

The LDPE resin layer of the obtained film was placed in a pulverizer by a peeling machine of 30 g, and a fine powder was produced under the conditions of a number of revolutions of 8000 × 9000 min. ^-1 (IN × OUT) and a treatment time of 2 minutes and 30 seconds.

Next, only the water-soluble resin was dissolved by stirring the obtained fine powder in warm water of 95 ° C for 2 hours, and only a fine powder of polymethyl methacrylate was obtained by filtration.

Claims (6)

A method for producing a fine powder, comprising the steps of: melting at least two kinds of resins and alternately laminating, forming a plurality of layers of a resin layer having a number of layers of 16 or more; pulverizing the multi-layered body; and dividing the laminated layer The steps of the layer. The method for producing a fine powder according to claim 1, wherein the step of performing the pulverization is integrated with the step of performing the division. The method for producing a fine powder according to claim 1 or 2, wherein the resin to be laminated is composed of polymethyl methacrylate resin (PMMA), polystyrene resin (PS), polymethyl methacrylate resin (PMMA), and An alicyclic olefin resin (COP) or an alicyclic olefin copolymer (COC), or a combination of a polymethyl methacrylate resin (PMMA) and a polyamide resin (PA). The method for producing a fine powder according to claim 1, wherein the step of dividing is performed by dissolving at least one resin. The method for producing a fine powder according to claim 4, wherein the resin dissolved in the step of dividing is a water-soluble resin. The method for producing a fine powder according to claim 1 or 4, wherein the fine powder has a particle diameter (d) represented by a center value of the particle diameter distribution of 1 μm or more and 300 μm or less, and an average thickness (t) of 0.1 μm or more and 50 μm or less. And the aspect ratio (d/t) is 6 or more and 300 or less.