JP2001198948A - Method for manufacturing additive-containing molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that a color master batch for the color molding of a film or sheet becomes ordered production in a master batch maker because a color is usually designated by a customer and cost reduction is difficult and, therefore, a quantitative supply system separate from the pulverization of a master batch and a molding material resin is proposed for the purpose of base coloration but the supply accuracy to an extruder and uniform mixing are not improved and the color/density irregularity of molded article is not avoided. SOLUTION: In manufacturing a molded article by using a miniature pellet- like additive-containing master batch of which the volume is about 1/10 or less as compared with natural resin pellets and the particle size is 0.5-1.5 mm and quantitatively supplying the master batch and the natural resin pellets to the material supply ports of separate molding machines, the master batch is preliminarity subjected to antistatic treatment and the lower end of a supply conduit of the master batch is set to a height position being 5-15% of the diameter of the conduit above a screw.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of mixing each individual master batch, for example, a red base, instead of using a toning master batch (a master batch matched to a specific color specified by a customer). Color pellets, white base color pellets, black base color pellets, and brown base color pellets are mixed in an appropriate ratio, and a mixture of pellets blended so that a specific color specified by a customer is formed is used as a coloring agent. The present invention relates to a method for producing a molded article containing an agent. More specifically, the present invention uses a mixture of base color pellets and a quantitative supply device thereof without using a tumbler or a Henschel mixer to mix a colorant and a thermoplastic resin, together with a natural resin that is a resin to be colored. In the case of supplying to a molding machine, by improving the accuracy of masterbatch pellet incorporation into the molding machine, that is, by improving the uniformity, it is possible to eliminate the color unevenness and density unevenness of the colored molded product, and to achieve a higher dilution ratio. And a molding method.

[0002]

2. Description of the Related Art Conventionally, molded products such as colored films and sheets have been continuously produced by extrusion molding methods such as inflation molding and T-die molding. As the coloring agent in this case,
Pigment is added to metal soap, polyethylene wax, etc. at a pigment concentration of 1
Dry color dispersed in a high concentration of 0 to 90% by weight,
A color masterbatch in which a pigment is dispersed at a high concentration in a resin is well known and used. A masterbatch maker usually tones (matches) a pigment to a color specified by a customer and supplies the color to a molding company.

[0003] In short, a color master batch is prepared by blending two or more kinds of pigments, a thermoplastic resin, a pigment dispersant and the like according to the quality (in this case, the color) required by the customer, and melting them in an extruder. It is made by uniform mixing and pelletizing. At the stage of hue inspection, the finished masterbatch may have a color different from the color requested by the customer. In such a case, add a pigment to this masterbatch and repeat the toning (color matching) process. At present, melting, mixing, homogenizing, and pelletizing to match the color with an extruder are inefficient.

[0004] In addition, in the case of a color masterbatch of such a thermoplastic resin, in the case of a liquid paint or printing ink at room temperature, the color can be adjusted only by mixing with a simple mixer. In terms of simplicity, there is a great difference, heat energy, time consumption is great, and labor is enormous. Toning master batches for custom colors (customer colors) are expensive.

[0005] However, the toning masterbatch is convenient from the customer's point of view.
It is used for molding many thermoplastic resins such as styrene resin, acrylic resin and ABS resin. Therefore, rationalizing the toning process is a major issue for master batch manufacturers. This is because the toning masterbatch must be produced in accordance with the customer's requirements, taking into account not only the color but also the quantity, delivery date, etc. Because they are struggling.

In view of the above, as one of the attempts to solve the problems of the toning masterbatch, a pellet masterbatch (base color masterbatch) having a high density is prepared for each color, and a plurality of types of different colors are prepared. It has been proposed by many that toning is performed by simply mixing the base color master batch in an appropriate ratio. However, when actually molded by such a method, color unevenness of the molded article, unevenness of density occurs, and a serious problem that uniformity in coloring of the molded article is not maintained occurs, and it is not put into practical use,
It has reached today. As one of the solutions, miniaturization of the masterbatch has been proposed, but it has not been fully embodied yet.

That is, when the conventional base color pellets are mixed and molded, the following problem occurs and they have not been put to practical use. (1) Color unevenness and density unevenness of the molded product occurs. The pellet size of the natural resin for molding is usually 2.5 to 3.5 mm, and the size of the base color pellet is 2.0 to 3.5 mm.
mm. When the pellet size is within this range, for example, the Munsell color chart gray color (achromatic color, lightness 8) has a compounding ratio of the base color pellet containing 60% titanium oxide and the base color pellet containing 1% carbon black of 100: 0. However, since the ratio of carbon black in the compounding is too small to mix uniformly, color unevenness and density unevenness occur.

(2) Making the base color pellets smaller is useful for improving and solving dilutability, but causes electrostatic separation and lowers mixing uniformity. If the maximum length of the pellet diameter of the masterbatch is reduced to about 0.5 to 1.5 mm, the surface area on which static electricity is charged increases, and the repulsion or aggregation of the particles due to static electricity becomes remarkable, and the kind of pigment included It was found that uneven charge distribution occurred in the mixture of the master batch due to different charging properties. Also, when the pellet size of the master batch is reduced to such a value, during the mixing operation with the natural resin having a pellet size of 2.5 to 3.5 mm, after mixing, and when putting them into the hopper of the molding machine, , When supplying to the molding machine,
Since the masterbatch slips off from the gap between the natural resins, the masterbatch is unevenly distributed in the resin and cannot be uniformly mixed. As a result, color unevenness and density unevenness of the molded product occur.

(3) The mixture of the natural resin for molding and the miniaturized masterbatch pellets cannot maintain uniformity on the hopper and during supply. Due to the recent development of pellet metering machines, attempts have been made to feed natural resin and masterbatch from separate supply lines on the hopper of the molding machine, and to make the melt uniform by rotating the screw of the extrusion molding machine. However, currently, in a commercially available fixed-quantity feeder, since the material is fed in the forward direction by the rotation of the screw in the extruder and at the same time, the force perpendicular to the axial direction is exerted by the centrifugal force due to the circular motion, the injected master batch pellets It does not move up and down and is not continuously and quantitatively supplied into the cylinder of the molding machine, but causes unevenness in the density of molded products such as films and sheets formed by the extrusion molding method. For this reason, this method has not been put to practical use in the extrusion molding method. However, JP
JP-A-279282 discloses an additive-containing thermoplastic resin composition in which the size of the pellet is strictly defined and the molded product having good uniformity, deflocculability, and dilutability can be obtained by separately supplying the resin with the natural resin. The injection molding method in which the entire amount of the molding material is intermittently supplied for each shot has already been put to practical use.

[0010]

DISCLOSURE OF THE INVENTION The present inventors diligently studied the reasons why the prior art could not achieve the object, and as a result of closely observing the above situation, it was found that the increase in the surface area due to the miniaturization of the pellet size was observed. It has never been noticed yet to prevent the increase in the amount of electrostatic charge, and to find out how to feed individual pellets to the extruder cylinder in a manner that enables uniform ingestion. Was found to be an issue that is being sought.

[0011]

Means for Solving the Problems To solve the above-mentioned problems, as a result of intensive studies, (1) For the color unevenness and non-uniformity of the molded product, the pellet size of the base color pellet was reduced, and X, Y, Z
Each dimension of the shaft was about 1/2 or less of that of the natural resin pellet, and the maximum length was 0.5 to 1.5 mm. (2) As a countermeasure against static electricity different for each base color masterbatch for each pigment, antistatic treatment was performed by changing the amount of the antistatic agent added according to the characteristics of the pigment. (3) In order to prevent separation and uneven distribution and to ensure continuous uniform supply to the molding machine, the lower end of the supply conduit for supplying the additive-containing master batch into the molding machine is located above the molding machine screw and By positioning the screw within a height range of 5 to 15% of the screw diameter, the uniformity of biting into the molding machine was improved. Only when the three elements of (1), (2), and (3) above were prepared, it was found that molding could be performed using a mixture of base color master batches for each color pigment instead of the toning master batch.

That is, the present invention is as shown in the claims section of the present specification, and is as follows.

According to the first aspect of the present invention, each dimension of the three-dimensional coordinate system of the X, Y, and Z axes is approximately １ ／ or less of that of the added resin (natural resin) pellet, and the maximum length thereof is When an additive-containing thermoplastic resin is extruded using a 0.5 to 1.5 mm mini-pellet-shaped additive-containing masterbatch, the resin pellets to be added and the masterbatch are individually mixed without being mixed in advance. In the method of manufacturing a molded article by supplying a fixed amount to the material supply port of the molding machine, the master batch is subjected to an antistatic treatment in advance, and the lower end of the supply conduit for supplying the master batch to the material supply port is located above the molding machine screw. This is a method for producing an additive-containing molded product, which is located in a height range of 5 to 15% with respect to the screw diameter.

According to a second aspect of the present invention, the additive contained in the masterbatch is at least one of a coloring pigment, a filler, a dispersant, an antistatic agent, an antioxidant, an ultraviolet absorber, and a flame retardant. A manufacturing method according to claim 1.

[0015] The invention according to claim 3 is the method according to claim 1 or 2, wherein the masterbatch is a mixture of two or more kinds of masterbatches each containing a different color and containing at least one coloring pigment. is there.

According to a fourth aspect of the present invention, there is provided the production method according to the third aspect, wherein the masterbatch is adjusted in advance so that its grain shape, size, and surface electric resistance value are close to each other, and is uniformly mixed at a desired ratio. It is.

The invention according to claim 5 is the production method according to any one of claims 1 to 4, wherein the masterbatch has a surface electric resistance value of 1.0 × 10 ¹³ Ω or less. .

The invention according to claim 6 is the invention wherein the masterbatch contains an organic antistatic agent in an amount of 0.1% for its own antistatic treatment.
The method according to any one of claims 1 to 5, wherein the content is 3 to 1.0% by weight.

The invention according to claim 7 is the production method according to any one of claims 1 to 6, wherein the additive-containing molded product is a continuous extrusion molded product such as an inflation film and a T-die film.

The invention according to claim 8 is an injection-molded article formed by intermittently injecting a material into a cavity of a mold in which an additive-containing molded article is opened and closed. 2. The production method according to item 1.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the pellet size of the masterbatch is about 1/2 or less of that of the natural resin,
Its maximum length was defined as 0.5 to 1.5 mm. The conventional toning masterbatch is usually mixed with natural resin pellets and supplied to a molding machine. Therefore, the pellet size is designed to be 2.5 mm to 3.5 mm in consideration of uniform mixing with the resin. . However, if the master batches such as red base color pellets, white base color pellets, black base color pellets, and brown base color pellets are mixed with this pellet size and supplied in a fixed amount separately from the natural resin, a small amount of additives will be added during compounding. In such a case, the uniform mixing property is reduced, so that it is difficult to accurately supply a small amount of additive to the molding machine, which causes color unevenness and density unevenness of the molded article.

The pellet size of the master batch is 0.5
When the diameter is smaller than mm, the workability is poor, such as scattering during work, and strong adhesion to the container due to static electricity.
If it is larger than 1.5 mm, the intended effect of improving the dilutability will be reduced. By setting the pellet size to 0.5 to 1.5 mm, the volume of the master batch is reduced to 1/10 to 1/30 of that of the conventional resin pellets.
While double dilution is the limit, it is possible to further improve the dilution ratio, improve mixing uniformity with the resin in the molding machine, dilutability, and the color gamut that can be toned To the same extent. In addition, color reproducibility and color stability were improved.

Next, the amount of the antistatic agent to be added to the base color masterbatch was defined for each pigment system. In the conventional extrusion molding process, in order to supply a mixture of the above-mentioned toned pellets of the pellet size and resin pellets to a molding machine,
The adverse effects of static electricity during the process have not occurred in the on-site extrusion molding line. For the current toning masterbatch, antistatic measures are taken from the viewpoint of "prevention of contamination" of the molded article. From the above viewpoints, JP-A-5-98096 and 7-
Japanese Unexamined Patent Publication No. 113031 proposes an antistatic measure for a molded article using an antistatic masterbatch, and Japanese Patent Application Laid-Open No. 9-165460 proposes an antistatic measure for a molded article using an adhesive film containing an antistatic agent.

However, when a mixture of two or more masterbatches is used for extrusion molding, a different charging state occurs for each color during mixing of the masterbatch, supply to a molding machine, and storage / transportation. Therefore, it is necessary to take an antistatic measure for each master batch. The chargeability of the masterbatch also depends on the type, amount, and characteristics of the additive used and whether or not surface treatment is performed. Also, as the pellet size decreases, the number of master batches per unit weight increases and the surface area also increases,
Due to the increase in the frequency of contact with the container, the charge amount generally increases, and the device is easily affected by static electricity from the container.

As described above, since the chargeability differs for each pigment, the maximum effect cannot be obtained if the antistatic agent is uniformly added in a fixed amount. When an excessive amount of the antistatic agent is added, when the molded article is a film, printability, heat sealability and the like are reduced. Therefore, as a result of intensive studies, the present inventors have found that the optimum addition amount is 0.3 to 0.5% for inorganic pigment-based masterbatches and 0.5 to 1.0% for organic pigment-based masterbatches. It has been found that the surface electric resistance value can also be reduced to less than 1.0 × 10 ¹³ Ω, which is practically no problem for the pigment No. In consideration of the influence of the antistatic agent on the masterbatch and the molded product, the addition amount needs to be minimized. With respect to the mixture of the master batches subjected to these antistatic measures, the mixing state of the master batches at the time of mixing, supply to the molding machine, storage and transportation was confirmed, and no separation or uneven distribution was observed.

Further, a mixture of a masterbatch having a pellet size of 0.5 to 1.5 mm is supplied in a fixed amount separately from natural resin pellets, and uniformly mixed and melted in an extruder to form a molded product having no color unevenness and density unevenness. The problem is how to supply the master batch to the screw of the molding machine with high accuracy. As a method, the masterbatch supplied quantitatively is merged with natural resin pellets on the way,
A method of feeding the resin to the molding machine together with the transfer of the resin (Fig. 3),
A method of supplying natural resin pellets and a masterbatch to a molding machine by completely different routes (Fig. 2), and a method of individually supplying natural resin and a masterbatch individually (
FIG. 4) can be considered. Method is to merge the master batch with the resin pellets before being fed into the molding machine, if the path from the junction to the molding machine screw is long,
While being conveyed together with the resin, each component of the master batch is unevenly distributed in the resin, which may cause color unevenness and density unevenness. Both methods are hardly affected by the resin, so they are supplied to the molding machine screw with high precision.However, when the screw is starved, each component of the masterbatch rebounds on the screw, and the bite becomes unstable. .

As a result of repeated studies on such a masterbatch supply method, when a masterbatch is supplied using an individual metering device, the masterbatch conduit is passed through a resin conduit filled with a natural resin, and the natural resin is supplied. It has been found that the method (FIG. 1) in which the masterbatch is bitten with the supply of the masterbatch into the molding machine is the best in biting the screw with high precision.

At this time, the distance from the lower end of the masterbatch conduit to the upper part of the screw is important, and the closer the distance is, the more accurately the masterbatch bites into the screw without being affected by the vertical movement of the resin accompanying the rotation of the screw. The further away you are, the more susceptible you are, and the less you eat. This distance is related to the screw diameter, and if it is within 5 to 15% of the screw diameter, the masterbatch can be engulfed without being affected by the vertical movement of the resin. For example, 3
By taking a distance of 2 to 5 mm for a 0 mm extruder and 6 to 18 mm for a 120 mm extruder, which is considered to be the largest at the extrusion molding site, the masterbatch is accurately inserted into the molding machine screw, and there is no density unevenness. It was found that a molded product having good color reproducibility was obtained. Beyond this range, the biting accuracy was reduced, and when there was a small amount of additive, the density unevenness became severe.

In order for the toning by the masterbatch of the present invention to replace the conventional toning masterbatch, it is indispensable to satisfy all three factors, and this can be solved for the first time.

Examples of the additives used in the present invention include organic and inorganic pigments and fillers.
As shown below, other additives can be used as long as the effects of the present invention are not impaired. Organic pigments, for example, azo-based pigments such as azo lake, insoluble azo, condensed azo, phthalocyanine blue, cyanine-based pigments such as phthalocyanine green, anthraquinone, perylene, perylene, such as slen-based pigments, quinacridone, dioxazine and the like condensed polycyclic pigments There is. Inorganic pigments, for example, titanium oxide, titanium-based pigments such as titanium yellow,
Red iron oxide pigments such as red iron oxide, yellow iron oxide, chromate pigments such as graphite and chromium vermillion, aluminate pigments such as cobalt blue, and carbon black.
Examples of the filler include calcium carbonate, aluminum silicate, silica sand, calcium hydroxide, talc, clay, and mica.

Examples of the dispersant used in the present invention include low molecular weight thermoplastic resins such as polyethylene wax, polypropylene wax and polystyrene wax having a relatively low melting point and softening point of 40 to 150 ° C., and modified products thereof or montan wax. And waxes such as microlistin wax and derivatives thereof, fatty acid compounds such as stearic acid and stearamide, and surfactants such as polyoxyethylene polypropylene block polymer and fatty acid sorbitan ester. Other additives include phenol-based (mono, bis, polymer type), sulfur-based, phosphorus-based antioxidants, ultraviolet absorbers, and flame retardants.

The antistatic agent for kneading the masterbatch used in the present invention may be a nonionic surfactant and may be any one which is generally known as an antistatic agent for kneading. There is no. For example, polyoxyethylene alkylamine, N, N-bis (2-hydroxylethyl) alkylamine, fatty acid ester of N, N-bis (2-hydroxylethyl) alkylamine, higher alcohol, fatty acid ester of polyhydric alcohol Ethylene fatty alcohol, polyoxyethylene alkyl phenyl ether and the like can be mentioned. One of these antistatic agents may be used, or two or more thereof may be used in combination.

In the present invention, the thermoplastic resin used as the base resin of the masterbatch is compatible with the resin to be processed and does not cause thermal decomposition or thermal degradation in the process of melt extrusion of the masterbatch. , Polyethylene resin,
There are polypropylene resin, polystyrene resin, polyamide resin and the like. Other than these, there is no problem as long as the dispersibility of the additive is good and the compatibility with the processed resin is good.

The base color masterbatch having a pellet size of 0.5 to 1.5 mm composed of the above additives, dispersant, resin and antistatic agent has a die hole of about 1.0 to 1.5 mm.
Using a die head with a diameter of 1.5 mm and 5 to 30 holes, while independently cooling the strand discharged from the extruder in a water tank, the take-up speed and the speed of the rotary blade are independently driven, and the length of the master batch, It is obtained by cutting and shaping with a pelletizer whose diameter can be controlled. In addition to the above strand method,
A masterbatch having a small pellet size of 0.5 to 1.5 mm can also be stably formed by an underwater hot cut method in which a base color melt extruded finely on a die surface is cut with a cutter while being cooled with water.

When molding using a mixture of a plurality of types of additive-containing master batches, such as a case where two or more color master batches are mixed and used, each master batch has its grain shape, size and surface. It is desirable that the electric resistance value or the like be adjusted in advance so as to approximate. According to the present invention,
The specific gravity does not need to be adjusted, but may be adjusted if desired. In the present invention, it is important that, in addition to this adjustment, the components are uniformly mixed in a desired ratio in advance.

In the present invention, the thermoplastic resin to be subjected to the molding process of the additive-containing material such as the coloring molding process includes polyethylene resin, polypropylene resin, polystyrene resin, and the like.
Homopolymer such as acrylic resin, vinyl acetate resin, polyamide resin, polyethylene terephthalate resin, polycarbonate resin, or copolymer such as acrylonitrile-butadiene-styrene resin, or thermoplastic elastomer, or glass fiber and thermoplastic resin There is a composite thermoplastic composite material.

Next, the present invention will be specifically described with reference to the drawings (FIG. 1) illustrating the masterbatch individual quantitative feeder used in the present invention and the feeding method thereof. In addition, this invention is not limited at all by this. First, before the film forming machine 1 is operated, the masterbatch addition rate is set by the masterbatch-specific feeder 2. The natural resin put in the supply hopper 4 is automatically supplied to the weighing hopper 5 below the shutter 7 by setting the shutter 7 to open and close automatically, and is fed into the opening of the molding machine through the resin supply conduit 3. You. When the film forming machine 1 is operated, the resin is continuously supplied into the inside of the forming machine according to the screw rotation speed.

Next, when the operation of the master batch feeder 2 is started, the shutter 12 is opened and the replenishing hopper 8 is opened.
The master batch mixed at a predetermined ratio is automatically supplied to the weighing hopper 9 and further to the screw opening for transporting the master batch, and the master batch load cell 10 functions so that the supply amount depends on the resin extrusion amount. Then, the rotation speed of the screw is controlled.

The masterbatch conveying screw has optimal clearance and pitch with the cylinder so that a masterbatch having a small pellet size can be conveyed with high accuracy. The masterbatch cut out of the screw passes through the conduit 11 and on the resin at the opening of the molding machine,
A stable film free of color and density unevenness is obtained by dropping to the above-mentioned predetermined position on the molding machine screw, biting it accurately with the conveyance of the resin, and mixing and homogenizing in the molding machine. be able to. The resin is consumed during the extrusion, but when the remaining amount in the weighing hopper falls below the lower limit, the load cell for resin 6 operates and the hopper 4 for replenishment is sequentially supplied from the hopper 4 for replenishment. The master batch is also replenished according to consumption.

The pellet shape in the present invention specifically refers to a spherical shape, a cubic shape, and a columnar shape. In particular, a cubic shape (a rectangular parallelepiped, a cubic, etc.), and a cylindrical pellet are formed by a combination of an extruder, a water tank, and a pelletizer. .

The method for producing a molded article containing an additive in the present invention is not limited to intermittent extrusion molding in which a material is supplied intermittently, such as an injection plate or a bottle, as well as an inflation film,
T-die film, etc. It can be applied to a continuous extrusion method in which a material is continuously supplied.

Although the present invention has been described mainly with respect to the case of a colorant master batch, other master batches can be uniformly added to a resin to be added (natural resin) without unevenness when a plurality of types are used in combination. Achieved similarly.

[0043]

The present invention will be described below with reference to examples. In the examples, parts and% are based on weight. Experiments A to D
Was done. Experiment A: Master batch conduit, distance between screws and color stability Experiment B: Pellet size and supply method of master batch, electrostatic scattering property, color stability Experiment C: Antistatic agent amount in master batch and surface electric resistance value Experiment D: Antistatic agent amount and charge amount in master batch, separation uneven distribution

Experiment A: Masterbatch conduit, distance between screws and color stability Examples 1 to 5 and Comparative Examples 1 and 2 Formulation of three base color masterbatches (1), (2) and (3) used in experiments Is shown below. (1) (2) (3) ----------------------------------------- ------------------------------- Isoindolinone Yellow 30 (Dolphin Cyan Yellow 3RLTN, Tikka Ikki) Carbon Black (Hyper Black # 30, Korea) 20 Titanium oxide (RFC-5, Tyuphone) 60 Polyethylene wax 30 47 (High wax 420P, Mitsui Chemicals) Low density polyethylene 40 33 40 (JF-635S, MFR: 7, Nippon Polyolefin) ----- -------------------------------------------------- ----------------- Total 100

Each of the above blended products was kneaded and extruded by an extruder to obtain a cylindrical master batch having a pellet size of 1.5 mm (average longest diameter, the same applies hereinafter). Then, (1) /
(2) / (3) = 18/5/77, and further, 1,000 ppm of Arcard C-50 (cationic antistatic agent, lion) was added and hand blended.
The masterbatch mixture is put into a hopper 8 of a masterbatch feeder 2 of the apparatus shown in FIG. 1 for carrying out the method of the present invention, and a high-density polyethylene (Hizex 5000S, Mitsui Chemicals) is used as a natural resin in a resin hopper 4. Of cubic pellets having a particle diameter of 3.0 mm were adjusted, and the distance between the lower end of the supply conduit and the screw was adjusted.
The dilution ratio of the master batch was set to 90 times, and each of the blown film extruders with different screw diameters was operated at 100 rpm, and after stabilization, the film processed for 1 hour was sampled every 10 m to evaluate the density unevenness. 1 is shown. Table 1 Distance between pipes and screws and color stability

[0046]

[Table 1]

* Density unevenness: The maximum value of the color difference (ΔE) of each film was evaluated using a color difference meter.

The color difference between the films is 0.5 to
If it is within 0.6, there is no practical problem. In an extruder with a screw diameter of 30 mm, if the distance between the screw and the conduit exceeds 5 mm, the resin will be affected by the vertical movement of the resin due to the rotational movement of the screw, and the bite accuracy of the masterbatch will deteriorate, and the color stability of the film will decrease. It can be seen that is decreased. In addition, when the screw diameter was large, this distance could be lengthened because the force for biting the resin was strong. With an extruder having a diameter of 120 mm, the color stability was good if it was within 18 mm.

Experiment B: Pellet size of masterbatch, supply method, static electricity scattering property, color stability Comparative Example 3 0.6 parts of isoindolinone yellow (3RLTN) / cyanine blue (fastogen blue 5050, Dainippon Ink) 0 .3 parts / carbon black (high black # 3
0) 0.8 parts / titanium oxide (RFC-5) 53.4 parts /
20 parts of polyethylene wax (420P) /24.9 parts of low-density polyethylene (JF-635S) are blended, mixed by a blender, and then kneaded and extruded by a single screw extruder to obtain a toning master batch having a pellet size of 3.5 mm. Was. This was mixed with the same high-density polyethylene pellets (HIZEX 5000S) as in Example 1 at a 25-fold dilution, and then charged into a material supply port of an inflation film forming machine, and processed into a film to obtain a standard film.

Comparative Example 4 The toning master batch obtained in Comparative Example 3 was diluted 90 times,
The film was processed similarly.

Examples 6 to 8 and Comparative Examples 8 and 9 The formulations of the four types of base color masterbatches used in the experiments are as follows. (4) (5) (6) (7) -------------------------------------- ---------------------------------- Isoindolinone Yellow (3RLTN) 30 Cyanine Blue (Fast Cannes 5050, Dainippon Ink) 30 Carbon black (Hyperak 30) 20 Titanium oxide (RFC5) 60 Polyethylene wax 30 30 47 Polyethylene 40 40 33 40 --------------------- -------------------------------------------------- -Total 100

Each of the above blended products was kneaded and extruded with an extruder to obtain the following cylindrical master batch. Example 6 Example 7 was also cylindrical and had a pellet size of 1.5 mm.
1.0 mm, and Example 8 a 0.5 mm master batch. As Comparative Example 8, a master batch having a pellet size of 2.0 mm was obtained, and as Comparative Example 9, a master batch having a pellet size of 0.3 mm was obtained. Then, (4) / (5) / (6) /
(7) = 2/1/8/89, and 1,000 ppm of ARKARD C-50 was further added, followed by hand blending. As in Example 1, after charging the master batch mixture into the hopper of the master batch feeder, the dilution ratio of the master batch was set to 90 times, the 30 mm blown film molding machine was operated at 100 rpm, and after stabilization,
The film processed for 1 hour is sampled every 10m,
Color unevenness and density unevenness were evaluated.

[0053]

Comparative Example 5 (FIG. 2) The method of cutting out the master batch is the same as in Example 6.
The cut master batch is supplied to the rear of the opening divided by a vertical partition plate in front and behind the molding machine along the slope of the conduit. On the other hand, the resin filled in the conduit is supplied to the molding machine in front of the opening, conveyed to the inside with the operation of the molding machine, and mixed with the master batch.

Comparative Example 6 (FIG. 3) The method of cutting out the master batch is the same as in Example 6.
The resin supplied from the weighing hopper passes through the outside of the roof-type partition plate at the bottom, and accumulates in the lower conduit,
Fill up to the molding machine opening screw. The masterbatch is cut out from the screw inserted from the back of the resin supply unit, and falls on the resin accumulated in the conduit. With the operation of the molding machine, the resin descends from the center of the conduit at a higher speed in the conduit, and the masterbatch is also supplied to the molding machine along with the resin.

Comparative Example 7 (FIG. 4) In this example, as in the case of the masterbatch, the resin is individually metered to the starved molding machine screw. Experiment B
Table 2 shows the results. Table 2 Supply method of masterbatch, pellet size, electrostatic scattering and color stability

[0057]

[Table 2]

：: good △: slightly poor ×: poor * 1) Color unevenness: Visual evaluation of non-uniformity due to pigment ghosting 2) Density unevenness: Evaluation of maximum value of color difference of each film by color difference meter

Regarding electrostatic scattering, according to Examples 6 to 8 and Comparative Examples 8 and 9, when the pellet size is 0.3 mm, the adhesion or scattering of the master batch is remarkable around the container, whereas when the pellet size is 0.5 mm or more, the handling is not performed. There was no problem in work. Regarding the dilutability, in Comparative Example 4, by increasing the dilution ratio with the normal pellet size, the density unevenness before and after the film was severe, and the dilutability was significantly reduced. Comparative Example 5
In Examples 7 to 6 and Example 6, differences were observed depending on the individual quantitative supply method. In Comparative Example 5, although the color stability is improved even at the same dilution ratio as in Comparative Example 4, when the masterbatch drops onto the molding machine screw, it jumps up on the screw, making it difficult to bite it with the set mixing ratio with high accuracy. As a result, color unevenness and density unevenness occurred, and a film of a stable color could not be obtained. In Comparative Example 6, since the cut masterbatch falls on the resin within a certain range, the descending speeds of the central masterbatch and the outer masterbatch in the conduit are different, so that the fluidity, It was easily affected by the resin due to the difference in particle size, and color unevenness and density unevenness were observed. Also in Comparative Example 7, since the masterbatch jumped up on the screw of the molding machine, the biting accuracy was not good, and color unevenness and density unevenness occurred. Examples 6 to 8 have little color unevenness and density unevenness, and it can be seen that they are optimal as a method for individually supplying a master batch with a resin.

Experiment C: Amount of Antistatic Agent in Masterbatch and Surface Electric Resistance Example 9 The formulation of the five base color masterbatches used in the experiment is as follows. (8) (9) (10) (11) (12) ----------------------------------- ------------------------------------- Titanium oxide (RFC-5) 60 120ED, Toda dialect) 40 Cyanine Green 30 (Fast Clean S, Dai Nippon Ink) Cyanine Blue (Fluor 5050) 30 Carbon Black (Hyper Black 30) 20 Polyethylene Wax 20 30 30 47 Polyethylene 40 40 40 40 40 33 ---- -------------------------------------------------- ------------------ Total 100

Each of the above-mentioned blended products has a resist PE1
32 (nonionic antistatic agent, Daiichi Kogyo Seiyaku) was added at various ratios, and after uniform mixing, kneaded and extruded with an extruder to obtain a cylindrical master batch having a pellet size of 3.5 mm.
100 to 300 of each were collected, sandwiched between press plates, and heated and pressed to obtain a sheet having a thickness of about 1 mm. This was cut into 4 cm squares, and the results of measuring the surface resistance of the master batch with an insulation resistance measuring instrument are shown in Table 3. Table 3 Amount of antistatic agent in masterbatch and surface electric resistance Unit: Ω

[0062]

[Table 3]

* Measured 3 days after the master batch was prepared. The inorganic pigment was added with an antistatic agent in an amount of 0.3% or more, and an organic pigment in an amount of 0.5% or more. × 10 ¹³ Ω or less).

Experiment D: Amount of antistatic agent and charge amount in masterbatch, separation and uneven distribution Example 10 The blending of the four base color masterbatches used in the experiment was as follows. (13) (14) (15) (16) -------------------------------------- ---------------------------------- Isoindolinone Yellow (3RLTN) 30 Quinophthalone Yellow 30 (Periotor Yellow 0961HD , BASF) Cyanine green (Clean S) 30 Titanium oxide (RFC5) 60 Polyethylene wax 30 30 30 Polyethylene 40 40 40 40 ------------------------ ------------------------------------------------ Total 100

After each of the above blended products was uniformly mixed, the mixture was kneaded and extruded with an extruder to obtain a cylindrical master batch having a pellet size of 1.5 mm. To the cyanine green masterbatch (15) having a high chargeability, resist PE120 as an antistatic agent was compounded with varying the addition amount from 0 to 1.0%, and kneaded and extruded. Then, (13) / (14) / (15) / (16) = 4 /
1 kg was blended at a ratio of 26/32/38, and 1,000 ppm of ARKARD C-50 was further added, followed by hand blending in a polyethylene bag. Table 4 shows the amount of the antistatic agent in the masterbatch using cyanine green and the separation and uneven distribution of the masterbatch mixture after storage. Table 4 Amount of antistatic agent and charge amount in master batch, separation and uneven distribution Charge amount Unit: kv

[0066]

[Table 4]

* 1) Charge amount: Average value measured at a position 25 mm away from the master batch after hand blending 30 times (number of repetitions: 5) and opening. (Measuring device: SIMCO FMX-0
01) 2) Separation / uneven distribution: visual evaluation ○: good △: slightly poor ×: poor

On storage day 0, the mixture is uniformly mixed only with the after-blending of the antistatic agent. However, after 20 days, if the antistatic agent is not kneaded into the master batch, green separation and uneven distribution occur. It is understood that separation and uneven distribution can be prevented by adding 0.5% or more to the master batch.
In addition, when evaluated by the charge amount, the after-mixing alone was 0.5 kv or less immediately after mixing. However, when the mixture stored for 20 days was mixed, the addition amount was increased to 0.3%, and the charge amount increased. It can be seen that there is almost no change with the addition of 0.5% or more, while it is unevenly distributed.

[0069]

According to the present invention, in the extrusion molding of the thermoplastic resin containing an additive containing an organic antistatic agent according to the present invention, the advantage that the pellet size is 0.5 to 1.5 mm is utilized, and a master batch individual quantitative supply device is used. By supplying the natural resin pellets and the natural resin pellets separately to the extruder, it is possible to provide a method for producing an additive-containing molded article that does not have color unevenness and density unevenness of the molded article and enables high dilution ratio. In addition, since the production can be rationalized and made more efficient, it is possible to cope with a small quantity, a large variety, and a short delivery time.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus in which the method of the present invention is performed.

FIG. 2 is a schematic view of an apparatus in which the method of Comparative Example 5 is being performed.

FIG. 3 is a schematic view of an apparatus in which the method of Comparative Example 6 is being performed.

FIG. 4 is a schematic view of an apparatus in which the method of Comparative Example 7 is being performed.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 film forming machine 2 masterbatch supply machine 3 resin supply conduit 4 resin supply hopper 5 resin measurement hopper 6 resin load cell 7 resin shutter 8 masterbatch supply hopper 9 masterbatch measurement hopper 10 masterbatch load cell 11 master Batch supply conduit 12 Master batch shutter

Continued on the front page F term (reference) 4F070 AA13 AC04 AC15 AC94 AE04 FA03 FB04 FC05 4F201 BA02 BC01 BC12 BC19 BD04 BD05 BK40 BN18 BN50 BQ08 BQ15 BQ16 BQ50 4F206 AA05 AA07 AB05 AB06 AB09 AB11 AB15 AB18 J01J01 J12F JQ11 4F207 AA05 AA07 AB05 AB06 AB09 AB11 AB12 AB18 AC01 AR12 KA01 KA17 KF01 KF02 KF12 KK12

Claims (8)

[Claims] 1. The dimensions of a three-dimensional coordinate system of the X, Y, and Z axes are approximately 1/2 or less of those of a resin-added (natural resin) pellet, and the maximum length is 0.5 to 1 .5mm
When extruding an additive-containing thermoplastic resin using an additive-containing masterbatch in the form of mini-pellets,
In the method of manufacturing a molded product by supplying the added resin pellets and the masterbatch individually to the material supply port of the molding machine without premixing, the masterbatch is assumed to have been subjected to antistatic treatment in advance, and the masterbatch is supplied with the material. A method for producing an additive-containing molded product, wherein a lower end of a supply conduit supplied to a mouth is positioned above a molding machine screw in a height range of 5 to 15% of a screw diameter. 2. The additive contained in the masterbatch is at least one of a coloring pigment, a filler, a dispersant, an antistatic agent, an antioxidant, an ultraviolet absorber, and a flame retardant.
The manufacturing method as described. 3. The method according to claim 1, wherein the masterbatch is a mixture of two or more masterbatches containing at least one coloring pigment and exhibiting different colors. 4. The production method according to claim 3, wherein the masterbatch is adjusted beforehand so that its grain shape, size and surface electric resistance value are close to each other, and is uniformly mixed at a desired ratio. 5. The masterbatch according to claim 1, wherein the surface electric resistance value is 1.0 × 10 ¹³ Ω or less.
The production method according to any one of the above. 6. The process according to claim 1, wherein the masterbatch contains 0.3 to 1.0% by weight of an organic antistatic agent for its own antistatic treatment. Method. 7. The production method according to claim 1, wherein the additive-containing molded product is a continuous extrusion molded product such as an inflation film and a T-die film. 8. The injection molded article according to claim 1, wherein the additive-containing molded article is an injection molded article molded by intermittently injecting a material into a cavity of a mold that opens and closes. Production method.