JPS60137933A - Production of colored resin composition - Google Patents

Abstract

PURPOSE:To produce a composition without peeling nor falling off a colorant at a low cost, by applying a colorant to the periphery of resin particles in the presence of a lubricant as a medium, feeding the resultant aggregated lumps of the resin particles having the colorant applied thereto to an air fluidized cooling bath, and pulverizing and cooling the aggregated lumps of the resin particles having the colorant. CONSTITUTION:Thermoplastic resin particles, a colorant and a lubricant having >=30 deg.C melting point are stirred in a mixer, and only the lubricant is melted and applied to the periphery of the particles in the presence of the melted lubricant as a medium. The resultant aggregated lumps of the resin particles having the colorant applied thereto are then fed from a feed inlet 1 to an air fluidized cooling bath and kept in the floating state in a fluidized part 3 above a perforated plate screen 7 by air blown from an air feed inlet 2. The aggregated lumps of the resin particles having the colorant applied thereto are then pulverized, dissociated into small particles, cooled and then taken out from a taking outlet 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for producing a colored resin composition used for producing a colored thermoplastic resin molded article.

More specifically, the present invention relates to a method for producing a colored resin composition in which a coloring agent is adhered to thermoplastic resin particles using a lubricant having a melting point of 30° C. or higher as a medium.

[Prior art]

As a method for coloring thermoplastic resin, Japanese Patent Application Laid-Open No. 47-307
No. 45, JP-A-49-99139 and JP-A-48-
The method described in No. 40856 is common.

That is, a coloring agent is attached to the surface of a thermoplastic resin using an adhesive as a medium, or the thermoplastic resin is heated to melt its surface and a coloring agent is attached thereto, and then the colored resin is extruded into an extruder. A method of heating, melting, and kneading is generally known. However, when using a colorant at a high concentration, especially a colorant whose melting point is higher than that of a thermoplastic resin, the colorant tends to peel off and fall off from the resin during the process of producing a colored resin composition. . Molded products using these colored resin compositions not only sometimes did not exhibit the desired color, but also were unsatisfactory in terms of appearance due to colored spots and poor dispersion of the colorant.

On the other hand, a lubricant with a melting point of 30°C or more at room temperature is stirred with the thermoplastic resin in a mixer, the lubricant is melted by frictional heat, and the coloring agent is attached to the thermoplastic resin using this lubricant as a medium. The colored resin composition 11 has good dispersibility without any shedding of the colorant, and is comparable in appearance.

However, colored resin compositions such as 1 and 2 can flow at temperatures above the melting point of the lubricant, but at temperatures below the melting point of the lubricant, the lubricant acts like an adhesive and causes the thermoplastic resins to adhere to each other. It becomes like this. To use this as a colored resin composition, it is necessary to apply mechanical force after cooling to crush the block (agglomerate) and dissociate it into small agglomerates or individual particles. However, in this pulverization step, there was a problem in that the coloring agent attached around the thermoplastic resin peeled off and fell off due to the force applied. In addition, such operations require labor and time, which poses a cost problem.

[Purpose of the invention]

An object of the present invention is to provide a method for producing a colored resin composition having excellent properties without the problems seen in the prior art as described above.

[Structure of the invention]

The method for producing a colored resin composition according to the present invention is to stir thermoplastic resin particles 1 a coloring agent and a lubricant with a melting point of 30°C or higher in a mixer, melt only the lubricant, and prepare thermoplastic resin particles using the lubricant as a medium. A coloring agent is attached to the rim, and then the colorant-attached resin particles are supplied to an air flow cooling tank to crush aggregates of the colorant-attached resin particles and cool the colorant-attached resin particles. It is characterized by

[Embodiment]

The thermoplastic resin used in the method of the present invention is not particularly limited, and includes methacrylic resins obtained by various polymerization methods such as bulk polymerization method, S-turbid polymerization method, emulsion polymerization method, and solution polymerization method. Any thermoplastic material may be used, such as styrene resin, AB8 resin, A8 resin, vinyl chloride resin, or nylon resin. The shape of the thermoplastic resin particles may be, for example, angular, cylindrical, hemispherical, bead-like, etc., and the shape does not matter as long as it is a particle.

Examples of lubricants having a melting point of 60° C. or higher used in the method of the present invention include higher fatty acid monoglycerides, such as stearic acid monoglyceride.

Linoleic acid monoglyceride, oleic acid monoglyceride 2
behenic acid monoglyceride, linoleic acid monoglyceride, etc. and sorbitan esters, such as stearic acid sorbitan ester.

Examples include sorbitan nocrumitate ester.

These ethylene oxide adducts may also be used. Also, polyalkylene glycol, oyohistearyl alcohol, cetyl alcohol, myristyl alcohol! 5 high M full: l-/L/.

Also included are commonly used lubricants such as higher fatty acids such as stearic acid. These lubricants can be used alone or in combination of two or more. The amount of these lubricants added is preferably 0.1 to 10 parts by weight per 100 parts by weight of the thermoplastic resin particles.

If the amount is less than 0.1 part by weight, the adhesion of the colorant may deteriorate. If the amount is more than 10 parts by weight, the physical properties of the resin may change.

On the other hand, the colorant used in the present invention refers to dyes, organic pigments, inorganic pigments, or fluorescent whitening agents that can be used in combination with these.

Specific examples of dyes include Diamond Resin Red H8, Red H, Red S, Red EL, Red LH, Yellow HL, and Yellow HC.

Yellow A, (Yellow〇, Orange Gll Orange H8
, orange, violet A, violet D, blue P, blue, blue H, blue N.

Brown A [both manufactured by Mitsubishi Chemical Industries, Ltd., product names], and Blast Red As% Red 3B.

Examples include Yellow FC, Yellow F5G, Orange G, Orange 3G, Violet RR, and Blue OA [all manufactured by Sumitomo Chemical Co., Ltd., trade names]. Specific examples of organic pigments include Permanent Red 4I (, First Yellow-08, % First Orange RR, First Piolet) J Cyanine Blue 81 Cyanine Blue BF [all manufactured by Dainichiseika Industries Co., Ltd., trade names]
, Cyanine Blue BN, Cyanine Green NB, Cyanine Green NY (all manufactured by Toyo Ink Manufacturing Co., Ltd.,
product name), etc. Specific examples of inorganic pigments are 1
Commonly used titanium oxide, barium sulfate, deep blue 1 ultramarine blue, carbon black, etc. can be mentioned. In addition, specific examples of fluorescent brighteners that can be used in combination with these include Mikawhite AT (manufactured by Mitsubishi Chemical Industries, Ltd., trade name), Kycor E and Kycor C (manufactured by Nisso Kako Co., Ltd., trade name), Kayalai) B (manufactured by Nippon Kayaku Co., Ltd., trade name), Plancomb-KUM (manufactured by Bayer AG, trade name), etc. The amount of the colorant used in the method of the present invention is 100% of the thermoplastic resin particles. For parts by weight, Q, 01
It is preferable that it is 10 parts by weight. If it is less than 1 part by weight, a colored composition that is of general value cannot be obtained; on the other hand, if it is more than 10 parts by weight, the color tone of the colored resin may fluctuate significantly and color spots may occur. .

In addition to these colorants and lubricants, it is also possible to use, for example, an ultraviolet absorber and a small amount of a spreading agent. The mixer used in the method of the present invention may be of any type as long as it has the function of uniformly mixing the thermoplastic resin, lubricant, and colorant.

For example, Super Mixer (manufactured by Yoda Seisakusho, product name),
Examples include tumbler type mixers.

Methods for melting only the lubricant include a method that utilizes the frictional heat generated between thermoplastic resins by stirring with a mixer, a method that uses external heating during stirring, and a method that heats the material in advance before stirring. etc. By heating by these methods, the coloring agent is deposited on the outer periphery of the thermoplastic resin particles using the molten lubricant as a medium when stirring in a mixer. Note that due to the adhesive force of the bath melting lubricant, the colorant-attached thermoplastic resin particles are bonded to each other to form an aggregate.

The "air flow cooling tank" used in the method of the present invention will be explained by using a colored resin assembly with a cooling air button supplied thereto. 1st rgA is an explanatory diagram showing an example of implementation of the present invention, and shows a longitudinal section of a cooling tank. In the figure, 1 is a supply port for the coloring composition supplied from M+SER, 2 is an air supply port, 3 is a flow section, 4 is an upper space, 5 is an air exhaust port & 6 is a coloring composition takeout port %7 is a perforated plate or screen. The coloring composition supplied from the mixer is supplied from the supply port 1 in a state where the temperature is higher than the melting point of the lubricant. The supplied coloring composition is kept in a floating fluid state in the flow section 3 above the perforated plate or screen 7 by the air blown from the air supply port 2, and here the colorant-adhered thermoplastic resin particles are aggregated. is crushed and dissociated into small agglomerates or individual resin particles, and the resin particles are cooled.

In this case, the velocity vo (means m& when there are no thermoplastic resin particles) of the air supplied to the cooling tank in the flow section 3 is relative to the terminal velocity Vt of the thermoplastic resin particles.
V. It is preferable to select such that ≧Q, lvl. At an air velocity as small as α1 vt , the pulverization and fluidization of the colored resin composition are insufficient.

The colored resin composition particles after cooling are not sufficiently dissociated and become block-shaped. Also, the air velocity V in the upper space 4 of the air flow cooling tank. is preferably selected such that v0≦cL4vt. At a higher air velocity 1, the colored resin composition particles that have risen above the flow section 3 are discharged by the cooling air through the air exhaust port 5 to the outside of the air flow cooling tank, and the yield of colored resin composition particles decreases. , which is disadvantageous in terms of cost. Therefore, the flow @5 and the air velocity VQ in the headspace 4
It is desirable to keep each of them within the above ranges. Air velocity V. In order to maintain this as described above, it is effective to use an air flow cooling tank in which the cross-sectional area of the upper space 4 is larger than the cross-sectional area of the flow section 3. The cooling air is exhausted to the outside of the air flow cooling tank through the air exhaust port 5, and is pulverized.
The cooled colored resin composition particles are taken out through the outlet 6.

〔Example〕

Next, the present invention will be specifically explained with reference to Examples.

[Example 1] Cylindrical pellet-shaped methacrylic resin 2 with a diameter of 3 and a length of 31
5 to 9, stearic acid monoglyceride (melting point 65°C)
0.25Kf and Diamond Resin Red HS 0.25
K9 was stirred and mixed for 20 minutes at a stirring rotation speed of 100 orpm using a European SOZ super mixer, and the resin temperature was brought to 70°C. It was then fed to the air flow cooling tank shown in figure w3.1. Air velocity in flow section 3 is 1.6 per second
It was set as m. This was 0.15 times the resin particle terminal velocity. The time required for cooling was approximately 5 minutes. The obtained colored resin composition maintained a granular shape, and the coloring agent attached thereto had a very uniform density rz. After heating and melting this colored resin composition in an extruder, it was shaped into a granular colored methacrylic resin i.
The color dispersibility of JP was very good.

[Example 2] 25 kg of beaded methacrylic resin with an average particle size Q of 4-
Oleic acid monoglyceride''-(melting point 40℃) 1.5
Kf and Guya Resin Yellow HL I Kg were stirred in a super mixer with an internal capacity of Sat at a rotational speed of 1100 Or.
The mixture was stirred and mixed for 20 minutes at a temperature of 50°C, and the resin temperature was set at 50°C. It was then fed to an air flow cooling tank as shown in the %m1 diagram. The air velocity in the flow section 3 was 0.14 m/s. This was 0.4 times the terminal velocity of the resin particles. The time required for cooling was approximately 5 minutes. The obtained colored resin composition maintained a granular shape, and the a-coloration of the attached colorant was very uniform. This colored resin composition was added to an uncolored methacrylic resin that had been melted in advance in an extruder, and 80% of the uncolored methacrylic resin was added to the extruder.
It was continuously added in an amount of 20 parts by weight per part by weight, kneaded in the extruder, and then shaped. The colored dispersibility of the obtained granular colored methacrylic resin was very good.

[Examples 3 to 5] Table 1 shows examples in which only the air velocity in the fluidizing section 3 of the air fluidizing cooling tank was varied among the examples shown in Example IK.

Table 1 Example 3 0.5 Defective Bu 3.3.2 Example 4 &
0 Good Granular Example 510 Good Colorant partially peeled off [Comparative Example 1] After stirring and mixing a formulation with the same composition as in Example 1 under the same conditions in the same mixer, the colored resin composition was placed in a stainless steel container. When I received it and let it cool down naturally, it took about 3 hours to cool down.
After cooling, the colored resin composition became block-like.

When this colored composition was loosened by hand in order to be shaped using an extruder, much time and labor was required, and furthermore, the coloring agent was partially peeled off from the methacrylic resin.

The color of the methacrylic resin obtained by extrusion molding this resin composition was uneven and unstable.

[Comparative Example 2] A formulation having the same composition as in Example 1 was stirred and mixed under the same conditions using the same mixer, and then cooled by blowing air on the mixer day while maintaining the stirring state. Almost all of it was peeled off and separated from the methacrylic resin.

〔Effect of the invention〕

The edge forming method of the present invention has the following advantages.

(1) It is possible to simultaneously crush and cool the colorant-attached resin particles, thereby shortening the processing time and saving labor.

(2) The produced colored resin composition is granular and has an extremely good adhesion of the colorant, and is easy to handle thereafter.

(3) The colored thermoplastic resin molded article produced using the produced colored resin composition has a good dispersion state of the coloring agent and is of high quality without colored spots.

(4) Since the produced colored resin composition has a uniform adhesion state of the colorant, the colorant concentration of the colored thermoplastic resin molded product produced using this colored resin composition is very stable. ing.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a specific example of a cold air flow cooling tank used in the method of the present invention. In the figure, 1 is the supply port of the colored resin composition supplied from the mixer, 2 is the air supply 0.3H flowing part%, 4 is the upper space,
5 is an air exhaust port, 6 is an outlet for the colored resin composition, and 7 is a perforated plate or screen. Patent applicant: Mitsubishi Rayon Co., Ltd. Patent attorney Akira Aoki Patent attorney Kazuyuki Nishidate (1) Yukio patent attorney Akira Yamaguchi Patent attorney Masaya Nishiyama

Claims (1)

[Claims] 1. When thermoplastic resin particles, a colorant, and a lubricant with a melting point of 30°C or higher are stirred in a mixer, only the lubricant is melted, and the thermoplastic resin particles are surrounded by using the molten lubricant as a medium. A coloring agent is attached to the resin particles, and then the colorant-attached resin particles are supplied to an air flow cooling tank to crush aggregates of the colorant-attached resin particles and cool the colorant-attached resin particles. A method for producing a colored resin composition. 2. The method according to claim 1, wherein the ratio of the thermoplastic resin and the lubricant in the colored resin composition is 0.1 to 10 parts per 100 parts by weight. (v) The method according to claim 1 or 2, wherein the ratio of the thermoplastic resin and the colorant in the colored resin composition is 0.01 to 10 parts by weight of the latter to 100 parts by weight of the former. .