JP5766906B2 - Method for producing pigment / resin composition - Google Patents

Description

  The present invention relates to a method for producing an efficient pigment / resin composition (including a colorant for an image recording agent and a colorant for other resins, the same shall apply hereinafter), and more particularly, has excellent pigment dispersibility. The purpose is to provide a streamlined production method of pigment / resin composition, colorant for general-purpose resin, colorant for image recording agent, coloring method using these colorants, image recording method, colored article, and recorded image. .

  Conventionally, a pigment / resin composition uses a dry powder pigment as a pigment, a colorant obtained by coloring a pigment on the surface of a resin pellet, a powdery or granular colorant obtained by mixing a pigment and a dispersant, and a plastic. A paste-like colorant dispersed in an agent, or a masterbatch in which a pigment, a resin, a dispersant and the like are kneaded at a high concentration are widely used.

  The master batch, which is a high-concentration pigment dispersion, is prepared by mixing dry powder pigment and resin in advance, and then multi-screw extruders such as single screw extruders and twin screw extruders, kneader kneaders, Banbury mixers, two rolls, three A method of kneading with this roll or the like is common. However, once dried, the pigment powder contains a large number of coarse secondary aggregate particles, and it is very difficult to re-disperse these secondary aggregate particles to primary particles.

  Therefore, as a pigment / resin composition with excellent dispersibility, aqueous pigment presscake or aqueous paste and resin are kneaded with a kneader such as a flasher or kneader and flushed to transfer the aqueous phase pigment to the resin phase. Then, a colorant for an image recording agent or a colorant for a plastic obtained by removing water after that is proposed (Patent Documents 1 to 3).

  In general, the method for producing a pigment / resin composition (colorant) in which the aqueous pigment paste and resin are kneaded to transfer the aqueous pigment to the resin phase and then remove water is batchwise. is there. Therefore, in such a method, manpower is required to move from the preparation of raw materials or mixing and kneading steps to the next step, and the processing time is long and the production efficiency of the colorant is poor.

Japanese Patent No. 2910945 Japanese Patent Publication No. 07-096663 Japanese Patent No. 3108228

  The method described in the above-mentioned patent document is a batch method using a kneader or flasher, so the production amount is limited by the size of the kneader or flasher, and it is difficult to cope with changes in demand such as an increase in production amount. . Also, in the production process, manpower is required to move from the raw material preparation or mixing / kneading process to the next process, and the processing time is long, resulting in poor production efficiency.

  As a result of intensive research to solve the above problems, the present inventors have made use of an extrusion kneader to produce a pigment / resin composition comprising a pigment and a heat-meltable resin. The method of using it in the state and putting it into an extruder together with the hot-melt resin powder and kneading was studied.

  As a result, the water-containing pigment and the heat-meltable resin powder are kneaded while being heated in the extruder, and moisture derived from the pigment is released from the vent port of the extruder as water and water vapor. It knead | mixed with resin at the temperature more than this melting temperature, discovered that a pigment disperse | distributes easily in resin, and came to complete this invention.

  In this method, the heating and kneading time of the pigment and the resin can be made shorter than that of the prior art, and a stable pigment / resin composition (with no pigment adhering to the device) can be obtained by using a quantitative supply device for supplying raw materials (Colorant) can be continuously produced, and can be directly connected to subsequent processes (for example, granulation process, etc.) to improve the production efficiency of the colorant. This method is economical and energy-saving. In addition, effects such as excellent dispersion of the pigment in the obtained colorant can be obtained.

That is, the present invention, a pigment and a heat-meltable resins, first the content of water [{water / (water, pigments and heat-meltable resin)} × 100] is 4-25 mass%, and, The second content ratio of moisture [{moisture / (water and pigment)} × 100] is continuously charged into an extrusion kneader having at least one vent port under the condition that it is 30% by mass or less , Kneading at a temperature equal to or higher than the melting temperature of the resin, dispersing the separated water and remaining water vapor from the vent port, kneading at a temperature equal to or higher than the melting temperature of the resin, and dispersing the pigment in the molten resin A method for producing a pigment / resin composition (colorant) is provided.

In the above-described present invention, the pigment and thermally fusible resins containing water, (1) heating and / or reduced pressure to mix after removal of the water, by heating and / or reduced pressure while mixing (2) removing water, or (3) heating and / or by removing water under reduced pressure after mixing, the first content [{water / (water moisture of the pigment and heat-meltable trees mixtures fat, pigment And heat-meltable resin)} × 100] is 4 to 25% by mass, and the second moisture content [{water / (water and pigment)} × 100] is 30% by mass or less. The hot melt resin is at least one polymer or at least one polymer alloy; the pigment is a chromatic, black, white organic or inorganic pigment or constitution Preferably it is a pigment .

  In the present invention, the extruder is a single-screw, twin-screw or multi-screw extruder having at least one vent port; the obtained pigment / resin composition is further kneaded in a kneader. If necessary, further pelletizing or sheeting with a continuous granulator or continuous sheeting machine; the kneader is a two-roll, three-roll, kneader, continuous open roll or extruder; Further, it is preferable to add a dispersant, an antioxidant, a light stabilizer, an ultraviolet absorber, an infrared absorber, an antistatic agent or a mixture thereof.

  The pigment / resin composition obtained in the present invention is useful as a colorant for general (general purpose) resins, and particularly useful as a colorant for image recording agents.

  The colorant for general-purpose resin or the colorant for image recording agent of the present invention may be a solid colorant containing a pigment in a high concentration, and the high concentration colorant may be a resin for image recording agent, a polymer, and / or Alternatively, an image recording agent can be obtained by kneading or dissolving in a monomer to disperse the pigment and subjecting it to a fine particle treatment. The fine particle treatment can be performed by a crushing granulation method, a suspension polymerization method, an emulsion dispersion method, or a spray granulation method.

  In addition, the present invention uses a method for coloring a general-purpose resin characterized by using the colorant for general-purpose resins, a colored article obtained by the coloring method, and the colorant for image recording agents. An image recording method characterized by the above, and a recorded image obtained by the image recording method are provided.

According to the present invention as described above, an aqueous presscake of pigment or an aqueous slurry of pigment is used as a pigment of a pigment / resin composition (colorant). there is no possibility to cause secondary aggregation of the particles.

  In the method of the present invention, the pigment can be transferred from the aqueous phase to the resin phase without using an organic solvent such as that used in flashing by a flasher or a kneader.

  In the method of the present invention, even a powdered pigment can be used as a raw material for the pigment / resin composition of the present invention by containing water. That is, when the powdered pigment is hydrated, the surface of the primary particles of the pigment becomes wet with moisture, the moisture acts as a dispersion aid for the pigment, and the pigment moves from the hydrated phase to the resin phase. And a pigment / resin composition used as a colorant for general-purpose resins and a colorant for image recording agents, which do not contain the coarse particles (secondary aggregated particles) and have excellent pigment dispersibility.

  Further, in the method of the present invention, the water content in the pigment can be reduced by increasing the pigment concentration of the pigment-containing hydrate to be used, compared to the aqueous press cake of the pigment used in the conventional flushing. Even with a small amount of water, the primary particles of the pigment do not form strong secondary agglomeration due to the presence of the moisture, and the pigment exists as a soft aggregate of primary particles. Or a pigment / resin composition having excellent dispersibility, which does not contain coarse pigment particles, by transferring the pigment from the water-containing phase to the resin phase by the action of water as a dispersion aid. The

  In the above method, even in the case of a pigment hydrate containing a very small amount of moisture, even if the pigment is aggregated, the aggregate is heated in the extruder so that the moisture in the interior is released from the pressure at the vent port. It is considered that the secondary agglomerated particles of the pigment are broken and dispersed into the primary particles, and the dispersed primary particle pigment is dispersed and diffused in the resin.

  In the present invention, a single-screw, twin-screw or multi-screw extruder having at least one vent port is used for heating and kneading, unlike batch production using a conventional kneader or flasher, The heating and kneading time is very short, and the pigment / resin composition can be continuously produced by using a quantitative supply device.

  Further, as a subsequent process, the present invention is applied to various devices such as a kneader such as an open roll continuous kneader for redispersion described later, a sheeting machine, a crusher, a pelletizer, a granulator, a storage tank, and a packaging machine. The kneading steps can be connected as they are, and the production efficiency of the pigment / resin composition is very high.

  In the present invention, when a twin screw extruder is used as the extruder, the water kneading by the twin screw extruder can be completed efficiently and in a short period of time. It is advantageous that the amount of water in the mixture of the resin and the resin is small because it takes less time to evaporate the water and uses less heat energy.

Next, the present invention will be described in more detail with reference to preferred embodiments. A preferred embodiment of the present invention is a use of a colorant for a general-purpose resin and a colorant for an image recording agent.
[Embodiment of colorant for general-purpose resin]
In the present invention, either the aqueous pigment presscake, the pigment aqueous slurry or the water-containing powder pigment and the hot-melt resin are mixed before or in the mixed state, and the moisture is 3 to 70 mass of the mass of both. %, Preferably about 4-50% by mass, more preferably about 4-25% by mass. Such moisture adjustment can be performed by a method of removing moisture by a water drawing rate in a filter press filtration step, a box-type dryer, a fluidized bed dryer, a vacuum dryer, or the like. In drying, the drying temperature is preferably lower than the melting point of the resin. Moreover, when using a powder pigment, a water | moisture content may be added. In the above, if the water content is less than 3% by mass, the prior drying is excessive and the pigment tends to agglomerate, and the water is instantly evaporated by heating in the extruder, and the action of water as a dispersion aid. Becomes insufficient, making it difficult to disperse the pigment. On the other hand, when the water content exceeds 70% by mass, the pigment water-containing material often becomes a slurry and is difficult to be injected into the extruder. Even if it can be injected into the extruder, the length of the cylinder of the kneading part is determined by the extruder, and if the moisture increases, it is difficult to raise the temperature of the pigment resin mixture to the resin melting temperature within that range. Thus, melt kneading cannot be performed and flushing cannot be performed or is insufficient.

  Further, at the time of mixing the raw materials before being put into the extruder, the mixing tank, the stirrer or the mixing system of the mixer may be heated to evaporate water from the raw material mixture, thereby adjusting the water content of the raw material mixture to a preferable water content. At this time, the heating temperature is preferably lower than the melting point of the resin. Preferably it is a temperature of 50-95 degreeC.

  The pigment and the resin whose water content has been adjusted are individually or as a mixture, continuously using a metering feeder, and preferably charged into a twin screw extruder. As the extruder used in the present invention, a twin-screw extruder is preferable, and as the twin-screw extruder, one having an L / D of 25 or more is used, preferably one having an L / D of 30 or more. A larger L / D is preferable for kneading. Further, the number of vent ports in the twin screw extruder is at least one, preferably two or more. A larger number of vent ports is advantageous for dissipating water evaporation of separated hot water and remaining water, but the number of vent ports must be determined in consideration of the balance with the kneading of the mixture.

  Examples of the pigment used in the present invention include conventionally known chromatic and black to white pigments, such as azo, polycondensed azo, azomethine, anthraquinone, phthalocyanine, diketopyrrolopyrrole pigments, Organic pigments such as quinophthalone pigments, perinone / perylene, indigo / thioindigo, dioxazine, quinacridone, isoindolinone, aniline black, metal complex pigments, and inorganic such as titanium oxide, iron oxide, and spinel structures Examples thereof include pigments and carbon black pigments. Among them, organic pigments having particularly high lipophilicity are preferred.

These pigments are preferably finely divided pigments. Examples of the fine particle formation method include (1) a method in which a pigment is dissolved in sulfuric acid and deposited in water to form a fine particle, and (2) the pigment is kneaded and ground together with salt and a viscous liquid to make it fine. And (3) a method in which a pigment is dispersed by a horizontal or vertical media disperser and refined.
In the present invention, the moisture in the pigment / resin hydrous mixture is not particularly limited, but in the present invention, in order to finish heating and kneading in a short time efficiently using a twin screw extruder, The smaller the amount of moisture, the less the temperature rise to the melting temperature of the resin by heating the pigment / resin water-containing mixture in the extruder, the moisture evaporation time, and the less the heat energy, the more advantageous.

  Therefore, there are a case where a pigment and resin wetted with water are mixed and put into an extruder, and a case where each is separately weighed and put into an extruder, but at the stage when it is put into the extruder The moisture in the pigment / resin-containing water-containing mixture is an amount corresponding to 3 to 70% by mass of the mixture, and the preferable moisture is an amount corresponding to about 4 to 50% by mass, more preferably about 4 to 25% by mass. . Examples of the powder pigment used in the present invention include carbon black pigments. However, even in the case of ordinary organic pigments and inorganic pigments, those for which an aqueous press cake of the pigment is not available can be used as a powder pigment. .

Examples of the heat-meltable resin used in the present invention include polyethylene, polypropylene, ethylene / propylene random, block or graft copolymers, α-olefin and ethylene or propylene copolymers, and ethylene / vinyl acetate copolymers. , Ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / butyl acrylate copolymer, polyethylene / polypropylene copolymer such as ethylene / acrylic acid copolymer, anhydrous Maleic acid-modified polypropylene, polybutadiene, polystyrene, styrene- (meth) acrylic acid ester copolymer, styrene-maleic acid ester copolymer, (meth) acrylic acid ester polymer and copolymer, styrene-diene copolymer Addition polymerization such as Resins, polyester resins, condensation resins such as epoxy resin, and various waxes and the like. The use ratio of the pigment and the resin is preferably 1 to 900 parts by mass of the pigment with respect to 100 parts by mass of the resin.
Here, when the amount of the pigment used is 11 to 300 parts by mass per 100 parts by mass of the resin, a high-concentration pigment coloring composition (master batch) is obtained. In the above, if the pigment is less than 1% by mass, the pigment content becomes too low and it is inefficient to use as a colorant, which is economically disadvantageous. Further, the melt viscosity of the high-concentration pigment coloring composition is low and the dispersion is insufficient. On the other hand, when the pigment exceeds 900% by mass, the resin content as the dispersion medium becomes too small, and the pigment and the resin are kneaded. Therefore, the pigment is discharged from the extruder with insufficient dispersion, and is not suitable as a colorant.

The method for producing the pigment / resin water-containing mixture in the present invention is not particularly limited, and can be obtained by a known method for preparing a pigment water-containing product.
(1) A method of uniformly mixing a pigment press cake and resin powder or resin chip,
(2) A method of adding a resin powder or a resin chip to a pigment slurry before filtration and filtering after uniformly mixing,
(3) In the case of an azo pigment, a method of synthesizing an azo pigment by adding resin powder or a resin chip to a solution of a coupling component and coupling,
(4) A method of injecting and kneading the pigment press cake and resin powder or resin chip separately into the extruder by automatic weighing,
(5) Water is added to the powder pigment, water is sufficiently absorbed and adsorbed on the pigment, and resin powder or resin chips are added to this, and mixed uniformly. (6) The powder pigment is filled with water vapor. For example, a method of sufficiently absorbing and adsorbing moisture to the pigment, adding it and resin powder or resin chip, and mixing them uniformly can be mentioned. In these methods, it is preferable to use the pigment / resin water-containing mixture obtained by any one of the methods (1) to (3) and (6).

  The method for producing the pigment / resin composition (colorant for general-purpose resin) of the present invention is obtained by separating the water-containing pigment / resin-containing mixture containing 3 to 70% by mass of water as described above and water vapor of residual water. In a kneading machine such as a vent type twin-screw extruder, a single-screw extruder or a multi-screw extruder having at least one vent port so as to discharge the This pigment is transferred to the resin phase. The vent port is installed upward, sideways, or downward, but preferably downward or sideways for discharging the separated hot water.

  In the production of the pigment / resin composition of the present invention, the water content of the pigment whose water content has been adjusted and the resin may be mixed in a mixer, and the water content of the pigment may be mixed with a mixer having a heating device. You may adjust the water | moisture content of a water-containing mixture, mixing resin.

  The water-mixed pigment / resin-containing mixture is charged into a kneader such as a twin screw extruder using a quantitative feeder. The heater heating temperature of the biaxial extrusion kneader is preferably set to 70 to 150 ° C. In the kneader, the resin is melted while heating and kneading under normal pressure, the pigment in the aqueous phase is transferred to the molten resin phase, and the separated moisture and water vapor are discharged from the vent port of the extruder. The kneaded product from which moisture has been removed is further kneaded in the same kneader, the pigment is finely dispersed in the resin, and extruded from the die of the extruder as the pigment / resin composition of the present invention (colorant for general-purpose resin). Then, it is cooled with a cooling belt, etc., and chipped with a pelletizer or a crusher.

  Thus, according to the present invention, it is possible to continuously and efficiently produce a colorant for resin. Furthermore, the above-mentioned colorant for resin is kneaded using a two-roll kneader, a three-roll kneader, a kneader kneader, a continuous open roll kneader, an extrusion kneader, or the like into the kneaded product. In order to completely disperse incompletely dispersed pigment particles that may be mixed in a trace amount, the dispersion is promoted, and the colorant for resin of the present invention excellent in dispersibility, sharpness and transparency can be obtained.

  Moreover, as a method for obtaining a resin colorant using the high-concentration pigment colorant of the present invention, a conventionally known method for producing a resin colorant can be mentioned. For example, the high-concentration pigment colorant, resin and additive of the present invention are mixed, and similarly using a two-roll kneader, a three-roll kneader, a kneader kneader, a continuous open roll kneader or an extrusion kneader. After kneading, chips are formed with a pelletizer or the like to obtain a resin colorant.

  Examples of the resin used for the resin colorant include general thermoplastic resins. For example, polyethylene resin, polypropylene resin, poly (meth) acrylic ester resin, polystyrene resin, styrene-acrylonitrile resin, acrylonitrile-butadiene-styrene resin, polyvinyl chloride resin, polyvinylidene chloride resin, Polyvinyl acetate resin, polyvinyl butyral resin, ethylene-vinyl acetate resin, ethylene-vinyl alcohol resin, polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), liquid crystal polyester resin (LCP), polyacetal resin ( POM), polyamide resin (PA), polycarbonate resin (PC), polyurethane resin, polyphenylene sulfide resin (PPS), etc. Command or polymer alloy thereof.

  Furthermore, the high-concentration pigment colorant of the present invention can be kneaded with a thermosetting resin such as an epoxy resin, a melamine resin, or an unsaturated polyester resin, a wax, or an emulsion by a known method to obtain each colorant.

In the present invention described above, the obtained pigment / resin composition can be further kneaded by a kneader and further pelletized or formed into a sheet by a continuous granulator or a continuous sheeting machine as required. The kneader can be a two-roll, three-roll, kneader, continuous open roll or extruder. A dispersant, an antioxidant, a light stabilizer, an ultraviolet absorber, an infrared absorber, an antistatic agent or a mixture thereof can be further added to the pigment / resin composition of the present invention.
Moreover, this invention provides the coloring agent for general purpose resin characterized by the above-mentioned. Moreover, this invention provides the coloring article characterized by using the coloring method of the general purpose resin characterized by using the coloring agent for general purpose resins of this invention, and this coloring method.

[Embodiment of Colorant for Image Recording Agent]
In the present invention, either the aqueous pigment presscake, the pigment aqueous slurry or the water-containing powder pigment and the hot-melt resin are mixed before or in the mixed state, and the moisture is 3 to 70 mass of the mass of both. %, Preferably about 4-50% by mass, more preferably about 4-25% by mass. Such moisture adjustment can be performed by a method of removing moisture by a water drawing rate in a filter press filtration step, a box-type dryer, a fluidized bed dryer, a vacuum dryer, or the like. In drying, the drying temperature is preferably lower than the melting point of the resin. Moreover, when using a powder pigment, a water | moisture content may be added. In the above, if the water content is less than 3% by mass, the prior drying is excessive and the pigment tends to agglomerate, and the water is instantly evaporated by heating in the extruder, and the action of water as a dispersion aid. Becomes insufficient, making it difficult to disperse the pigment. On the other hand, when the water content exceeds 70% by mass, the pigment water-containing material often becomes a slurry and is difficult to be injected into the extruder. Even if it can be injected into the extruder, the length of the cylinder of the kneading part is determined by the extruder, and if the moisture increases, it is difficult to raise the temperature of the pigment resin mixture to the resin melting temperature within that range. Thus, melt kneading cannot be performed and flushing cannot be performed or is insufficient.

  Further, at the time of mixing the raw materials before being put into the extruder, the mixing tank, the stirrer or the mixing system of the mixer may be heated to evaporate water from the raw material mixture, thereby adjusting the water content of the raw material mixture to a preferable water content. At this time, the heating temperature is preferably lower than the melting point of the resin. Preferably it is a temperature of 50-95 degreeC.

  The pigment and the resin whose water content has been adjusted are individually or as a mixture, continuously using a metering feeder, and preferably charged into a twin screw extruder. As the extruder used in the present invention, a vent type twin screw extruder is preferable. As the twin screw extruder, one having an L / D of 25 or more is used, and preferably one having an L / D of 30 or more is used. To do. A larger L / D is preferable for kneading. Further, the number of vent ports of the twin screw extruder is at least one, preferably two or more so as to discharge the separated hot water or the remaining water vapor. A larger number of vent ports is advantageous for the diffusion of water evaporation, but the number of vent ports must be determined in consideration of the balance with the kneading of the mixture. The vent port is installed upward, sideways, or downward, but preferably downward or sideways for discharging the separated hot water.

  Examples of the pigment used in the present invention include conventionally known chromatic and black to white pigments, such as azo, polycondensed azo, azomethine, anthraquinone, phthalocyanine, diketopyrrolopyrrole pigments, Organic pigments such as quinophthalone pigments, perinone / perylene, indigo / thioindigo, dioxazine, quinacridone, isoindolinone, aniline black, metal complex pigments, and inorganic such as titanium oxide, iron oxide, and spinel structures Examples thereof include pigments and carbon black pigments. Among them, organic pigments having particularly high lipophilicity are preferred.

These pigments are preferably finely divided pigments. Examples of the fine particle formation method include (1) a method in which a pigment is dissolved in sulfuric acid and deposited in water to form a fine particle, and (2) the pigment is kneaded and ground together with salt and a viscous liquid to make it fine. And (3) a method in which a pigment is dispersed by a horizontal or vertical media disperser and refined.
In the present invention, the moisture in the pigment / resin hydrous mixture is not particularly limited, but in the present invention, in order to finish heating and kneading in a short time efficiently using a twin screw extruder, The smaller the amount of moisture, the less the temperature rise to the melting temperature of the resin by heating the pigment / resin water-containing mixture in the extruder, the moisture evaporation time, and the less the heat energy, the more advantageous.

  Therefore, there are a case where a pigment and resin wetted with water are mixed and put into an extruder, and a case where each is separately weighed and put into an extruder, but at the stage when it is put into the extruder The moisture in the pigment / resin-containing water-containing mixture is an amount corresponding to 3 to 70% by mass of the mixture, and the preferable moisture is an amount corresponding to about 4 to 50% by mass, more preferably about 4 to 25% by mass. . Examples of the powder pigment used in the present invention include carbon black pigments. However, even in the case of ordinary organic pigments and inorganic pigments, those for which an aqueous press cake of the pigment is not available can be used as a powder pigment. .

  As the resin used in the present invention, a resin used in a conventionally known colorant for an image recording agent is used. When a high-concentration colorant is produced, a masterbatch carrier resin compatible with the colorant is used. Can also be used. For example, condensation resins such as polyester resins and epoxy resins, polystyrene, styrene- (meth) acrylic acid ester copolymers, styrene-maleic acid ester copolymers, (meth) acrylic acid ester polymers and copolymers Further, addition polymerization resins such as styrene-diene copolymers, polyethylene resins and polypropylene resins, and various waxes are used. Among the above resins, preferred are resins that have a melting point or softening point of about 150 ° C. or lower, preferably 130 ° C. or lower and are solid at room temperature. The ratio of the pigment and the resin component varies depending on the purpose of the colorant for the image recording agent. In the case of a high concentration colorant, the pigment content is 20 to 70% by mass. In the case of an image recording agent such as a developer, The pigment content is 1 to 20% by mass.

The method for producing the pigment / resin water-containing mixture in the present invention is not specifically limited, but may be obtained by a known method for preparing a pigment / resin water-containing mixture.
(1) A method of mixing a pigment press cake and a resin powder,
(2) A method in which resin powder is added to the pigment slurry before filtration, and the mixture is filtered after uniform mixing; and (3) In the case of an azo pigment, the resin powder is added to the solution of the coupling component, coupled to azo Examples include a method of synthesizing a pigment. It is preferable to use a pigment / resin-containing water mixture obtained by any one of the methods (1) to (3).

  The method for producing the pigment / resin composition (colorant for image recording agent) according to the present invention comprises the above-described pigment / resin water-containing mixture containing 3 to 70% by mass of water having at least one vent port. In this method, a water phase pigment is transferred into a resin phase by continuously kneading at a melting temperature in a kneader such as a screw extruder, a single screw extruder or a multi-screw extruder.

  In the production of the pigment / resin composition of the present invention, the water content of the pigment whose water content has been adjusted and the resin may be mixed in a mixer, and the water content of the pigment may be mixed with a mixer having a heating device. You may adjust the water | moisture content of a water-containing mixture, mixing resin.

  The water-mixed pigment / resin-containing mixture is charged into a kneader such as a twin screw extruder using a quantitative feeder. The heater heating temperature of the biaxial extrusion kneader is preferably set to 70 to 150 ° C. In the kneader, the resin is melted while heating and kneading under normal pressure, the pigment in the aqueous phase is transferred to the molten resin phase, and the separated moisture and water vapor are discharged from the vent port of the extruder. The kneaded product from which moisture has been removed is further kneaded in the same kneader, the pigment is finely dispersed in the resin, and extruded from the die of the extruder as the pigment / resin composition of the present invention (colorant for general-purpose resin). Then, it is cooled with a cooling belt, etc., and chipped with a pelletizer or a crusher.

  As described above, the present invention can continuously and efficiently produce a pigment / resin composition (colorant for an image recording agent). Furthermore, the above-mentioned colorant for image recording agent is kneaded using a two-roll kneader, a three-roll kneader, a kneader kneader, a continuous kneader, or an extrusion kneader to promote pigment dispersion. In addition, a colorant for an image recording agent excellent in sharpness and transparency can be obtained.

As a method for obtaining an image recording agent using the high-concentration pigment colorant of the present invention, naturally, a conventionally known method for producing an image recording agent can be mentioned.
(1) A method by a pulverization granulation method in which the high-concentration pigment colorant of the present invention is dissolved in an oligomer, a charge control agent is added, condensation polymerization is performed, and pulverization classification is performed.
(2) A suspension polymerization method in which the high-concentration pigment colorant of the present invention is dissolved in a monomer and polymerized,
(3) A method in which other necessary resin and charge control agent are added to the high-concentration pigment colorant of the present invention, and a solvent solution or a melt containing the resin and charge control agent is emulsified and granulated, and (4) For the image recording agent of the present invention, by adding other necessary resin and charge control agent to the high-concentration pigment colorant of the present invention and spray granulating a solvent solution or a melt containing the resin and charge control agent. Colorants can be produced.

In the present invention described above, the obtained pigment / resin composition can be further kneaded by a kneader and further pelletized or formed into a sheet by a continuous granulator or a continuous sheeting machine as required. The kneader can be a two-roll, three-roll, kneader, continuous open roll or extruder. A dispersant, an antioxidant, a light stabilizer, an ultraviolet absorber, an infrared absorber, an antistatic agent or a mixture thereof can be further added to the pigment / resin composition of the present invention.
In addition, the present invention provides a colorant for an image recording agent obtained by the above method. The present invention also provides an image recording method using the colorant for an image recording agent of the present invention, and a recorded image obtained by the image recording method.

  EXAMPLES Next, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited at all by these examples. In the text, “part” or “%” is based on mass.

[Examples of general-purpose resin colorants (I)]
Example A-1 (Production of high-concentration colorant and coloring of resin)
(1) Copper phthalocyanine blue pigment (CI Pigment Blue 15: 3, hereinafter abbreviated as “PB15: 3”) Water content of a pigment obtained by removing water from an aqueous presscake under reduced pressure (pigment content: 88%, moisture : 12%) 34.1 parts of polyethylene resin (ethylene-α olefin copolymer, melting point: about 60 ° C.) was mixed for 2 minutes with a Hensyl mixer, and 3 vents with a quantitative feeder It put into the twin screw extruder (L / D = 52) which has a mouth. The heater temperature of the twin screw extruder was set so as to be gradually increased to 60 to 140 ° C. Moisture was discharged from the downward vent port close to the charging port for a while after the mixture was charged, and water vapor was ejected from the next vent port. There was almost no water vapor from the vent port near the die at the tip of the extruder. The high-concentration colorant extruded from the die was cooled in a cooling water tank and chipped with a pelletizer. Hereinafter, this high concentration colorant is referred to as “blue high concentration colorant-1”.

(2) The blue high-concentration colorant-1 obtained in (1) above was blended with polypropylene (random copolymer, MFR: 30) so that the final pigment concentration was 0.3%, and kneaded with a single screw extruder. Chip. When the chip was molded by a molding machine, a blue clear and transparent molded plate was obtained. When the surface of the molded plate was observed with a microscope, the pigment particles were finely dispersed.

Example A-2 (Manufacture of high-concentration colorant and coloring of resin)
(1) Copper phthalocyanine blue pigment (PB15: 3) 42.9 parts of a pigment hydrate (pigment content: 70%, moisture: 30%) obtained by removing moisture from an aqueous presscake under reduced pressure, and a polypropylene resin (polypropylene wax, 57.1 parts having a melting point of about 87 ° C. were mixed for 2 minutes with a Hensyl mixer, and charged into a twin-screw extruder (L / D = 52) having three vent ports with a quantitative feeder.

  The heater temperature of the twin screw extruder was set so as to be gradually increased to 60 to 140 ° C. Moisture was discharged from the downward vent port close to the input port for a while after charging the mixed material, and water vapor was discharged from the next vent port. There was almost no water vapor from the vent port near the die at the tip of the extruder. The high-concentration colorant extruded from the die was cooled in a cooling water bath and chipped with a pelletizer. The obtained colored chip was kneaded with an open roll continuous kneader to obtain a blue high-concentration colorant. Hereinafter, this blue high-concentration colorant is referred to as “blue high-concentration colorant-2”.

(2) Blue high-concentration colorant-2 obtained in (1) above was blended with polypropylene (random copolymer, MFR: 30) so that the final pigment concentration would be 0.3%, and kneaded with a single screw extruder. Turned into. When the chip was molded by a molding machine, a blue clear and transparent molded plate was obtained. When the surface of the molded plate was observed with a microscope, the pigment particles were finely dispersed.

Examples A-3 to 5 (Manufacture of high-concentration colorant and coloring of resin)
According to the method described in Example A-2, high-concentration colorants were respectively prepared using the materials shown in Table A-1 below instead of the materials used in Example A-2. The water content of the quinacridone pigment and the water content of the monoazo yellow pigment were prepared by removing moisture from the aqueous press cake of each pigment under reduced pressure, and the water content of the carbon black pigment was carbon black with water vapor in a sealed container. Prepared by wetting the pigment. In addition, PR122, PY74, and PBK7 indicate the numbers of the pigments of the color index, as in PB15: 3.

  Single-screw extruder blended with high density colorants of red, yellow and black obtained in Examples A-3 to 5 with polypropylene (random copolymer, MFR: 30) to a final pigment concentration of 0.3% And kneaded into chips. When chips were molded with a molding machine, clear and transparent molded plates of each color were obtained. When the surface of each color molding plate was observed with a microscope, the pigment particles were finely dispersed.

Reference Example A-6 (Production of high concentration colorant and resin coloring)
(1) 300 parts of an aqueous slurry of copper phthalocyanine blue pigment (PB15: 3) (pigment content 10%, moisture 90%) was put into a stirring tank. Next, 70 parts of the polypropylene resin powder used in Example A-2 was added and mixed with stirring for 20 minutes.

  The mixture was filtered with a filter press filter and heated with a box dryer set at 55 ° C. for 20 hours to obtain a water-containing pigment / resin mixture containing 16.7% of water. In the same manner as in Example A-1, it was charged into a twin-screw extruder with a quantitative feeder and kneaded. The high-concentration colorant extruded from the die was cooled in a cooling water bath and chipped with a pelletizer. Further, the chip was kneaded with two heated rolls to obtain a blue high-concentration colorant. Hereinafter, this blue high concentration colorant is referred to as “blue high concentration colorant-3”.

(2) Blue high-concentration colorant-3 obtained in (1) above was blended with polypropylene (random copolymer, MFR: 30) so that the final pigment concentration would be 0.3%, and kneaded with a single screw extruder to give a chip. Turned into. When the chip was molded by a molding machine, a blue clear and transparent molded plate was obtained. When the surface of the molded plate was observed with a microscope, the pigment particles were finely dispersed.

Example A-7 (Production of colorant for resin and coloring of resin)
(1) Blue high-concentration colorant-1 produced in Example A-1 (pigment content: 30%) 33.3 parts and polypropylene (random copolymer, MFR: 30) 66.7 parts were blended and mixed after biaxial It was put into an extruder and kneaded. The colorant discharged from the die of the extruder was cooled in a water tank and chipped with a pelletizer to obtain a polypropylene masterbatch (colorant for resin) having a pigment content of 10%. Hereinafter, it is referred to as “blue colorant-1”.

(2) The obtained blue resin colorant-1 was blended with polypropylene (random copolymer, MFR = 30) so that the final pigment concentration was 0.3%, and kneaded with a single screw extruder to form a chip. When the chip was molded with a molding machine, a blue clear and transparent molded plate was obtained. When the surface of the molded plate was observed with a microscope, the pigment particles were finely dispersed.

[Example of Coloring Agent for Image Recording Agent (II)]
Example B-1
(1) Production of high-concentration colorant for image recording agent Copper phthalocyanine blue pigment (PB15: 3) Water content of pigment obtained by removing moisture from aqueous presscake under reduced pressure (pigment content: 87%, moisture: 13%) 5 parts and 70 parts fine powder of polyester resin (condensed polyester mainly composed of propylene oxide addition diol of bisphenol A and terephthalic acid, melting point of about 98 ° C., glass transition point of about 58 ° C., weight average molecular weight of about 15,000) The mixture was mixed for 2 minutes with a Hensill mixer, and charged into a twin-screw extruder (L / D = 52) having three vent ports with a quantitative feeder.

  The heater temperature of the twin screw extruder was set so as to be gradually increased to 60 to 140 ° C. Moisture was discharged from the downward vent port close to the input port for a while after charging the mixed material, and water vapor was discharged from the next vent port. There was almost no water vapor from the vent port near the die at the tip of the extruder. The high-concentration colorant for image recording agent extruded from the die was carried while being cooled on a cooling steel belt, and crushed into coarse particles by a crusher. When this was placed on a slide glass, melted by heating and observed with a microscope, the pigment particles were finely dispersed. Moreover, 105 degreeC heat loss water | moisture content by an infrared moisture meter was 0.4%.

(2) Manufacture of image recording agent Next, 11 parts of the high concentration colorant for image recording agent containing the blue pigment obtained above and 3 parts of the aluminum complex salt negative charge control agent were added to 86 parts of the polyester resin used above and The mixture was kneaded according to the method, cooled and coarsely crushed, then finely pulverized with a jet mill and classified to obtain a fine powder of a blue image recording agent of 3 to 10 μm. Colloidal silica was added to this as a fluidizing agent and mixed with carrier magnetic iron powder to obtain a cyan electrophotographic developer. When this was used for copying with a full-color electrophotographic copying machine, a clear cyan image was obtained.

Examples B-2 to 4
In accordance with the method described in Example B-1 (1), each of the materials shown in Table B-1 below was used instead of the material used in Example B-1 (1), and each of the high concentrations for the image recording agent was used. Made a colorant. The hydrated quinacridone pigment and the hydrated monoazo yellow pigment remove water from the aqueous press cake under reduced pressure to adjust the moisture, and the hydrated carbon black pigment wets and disperses the carbon black pigment in water, It was prepared by filtering and removing water under reduced pressure. In addition, PR122, PY74, and PBK7 indicate the numbers of the pigments of the color index, as in PB15: 3.

  Further, in accordance with the method described in Example B-1 (2), instead of the high-density colorant for image recording agent used in Example B-1 (2), for image recording agent described in Table B-2 below. Using the high-concentration colorant and the polyester resin used in Example B-1, electrophotographic dry developers (image recording agents) of the respective colors were prepared.

Using the dry developers of Examples B-2, 3 and 4, each was copied on a negatively charged two-component full color developer copier, and the clear color images shown in Table B-2 were obtained. In addition, using the four color developers of Examples B-1, 2, 3 and 4, clear color images were obtained. When copied to a transparent polyester film for an overhead projector, an image showing a clear image on the screen was obtained.

Reference Example B-5
(1) Production of high-concentration colorant for image recording agent Aqueous press cake of 70 parts of fine powder of polyester resin and copper phthalocyanine blue pigment (PB15: 3) used in Example B-1 (1) (pigment content 30%) , 70% moisture) was mixed with a Hensyl mixer in the same manner as in Example B-1 (1), and charged into a twin-screw extruder (L / D = 52) having three vent ports. And kneaded. Water was discharged from the downward vent port close to the input port, water vapor spouted from the next vent port, and almost no water vapor was discharged from the vent port close to the die.

  The high-concentration colorant for image recording agent extruded from the die was carried on a cooling steel belt while being cooled, and crushed into coarse particles by a crusher. When this was placed on a slide glass, melted by heating and observed with a microscope, the pigment particles were finely dispersed. Moreover, 105 degreeC heat loss water | moisture content by an infrared moisture meter was 0.5%.

(2) Manufacture of image recording agent Next, 11 parts of the high concentration colorant for image recording agent containing the blue pigment obtained above and 3 parts of the aluminum complex salt negative charge control agent were added to 86 parts of the polyester resin used above and The mixture was kneaded according to the method, cooled and coarsely crushed, then finely pulverized with a jet mill and classified to obtain a fine powder of a blue image recording agent of 3 to 10 μm. Colloidal silica was added to this as a fluidizing agent and mixed with carrier magnetic iron powder to obtain a cyan electrophotographic developer. When this was used for copying with a full-color electrophotographic copying machine, a clear cyan image was obtained.

Reference Example B-6
(1) Production of high-concentration colorant for image recording agent 300 parts of an aqueous slurry of copper phthalocyanine blue pigment (PB15: 3) (pigment content 10%, moisture 90%) was put into a stirring tank. Next, 70 parts of a fine powder of the polyester resin used in Example B-1 (1) was added and mixed with stirring for 20 minutes. The mixture was filtered with a filter press filter and heated with a box dryer set at 55 ° C. for 20 hours to obtain a water-containing pigment / resin mixture containing 16.7% moisture. In the same manner as in Example B-1 (1), this water-containing mixture was charged into a twin screw extruder and kneaded.

  Water was discharged from the downward vent port close to the input port, water vapor spouted from the next vent port, and almost no water vapor was discharged from the vent port close to the die. The high-concentration colorant for image recording agent extruded from the die was carried on a cooling steel belt while being cooled, and crushed into coarse particles by a crusher. When this was placed on a slide glass, melted by heating and observed with a microscope, the pigment particles were finely dispersed. Moreover, 105 degreeC heat loss water | moisture content by an infrared moisture meter was 0.4%.

(2) Manufacture of image recording agent Next, 11 parts of the high concentration colorant for image recording agent containing the blue pigment obtained above and 3 parts of the aluminum complex salt negative charge control agent were added to 86 parts of the polyester resin used above and The mixture was kneaded according to the method, cooled and coarsely crushed, then finely pulverized with a jet mill and classified to obtain a fine powder of a blue image recording agent of 3 to 10 μm. Colloidal silica was added to this as a fluidizing agent and mixed with carrier magnetic iron powder to obtain a cyan electrophotographic developer. When this was used for copying with a full-color electrophotographic copying machine, a clear cyan image was obtained.

Reference examples B-7 to 9
In accordance with the method described in Reference Example B-6 (1), each of the materials shown in Table B-3 below was used instead of the material used in Reference Example B-6 (1), and each of the high concentrations for the image recording agent was used. Made a colorant. Further according to the method described in Reference Example B-6 (2), for image recording material in place of the image recording agent for the high-concentration coloring agent used was noted in Table B-4 below in Reference Example B-6 (2) Using the high-density colorant and the polyester resin used in Reference Example B-6, electrophotographic dry developers for each color were prepared.

Using the dry developers of Reference Examples B-7, 8 and 9 obtained above, each was copied with a negative-charge two-component full-color developer copying machine, and a clear color image shown in Table B-4 was obtained. It was. Further, using the four color developers of Reference Examples B-6, 7, 8, and 9, clear color images were obtained. When copied to a transparent polyester film for an overhead projector, an image showing a clear image on the screen was obtained.

Example B-10
(1) Production of high-concentration colorant for image recording agent 70 parts of polyester resin fine powder used in Example B-1 (1) and copper phthalocyanine blue pigment (PB15: pigment content adjusted to 87% with a dryer) 3) A twin-screw extruder (L / D = 52) having 3 vent ports mixed with 34.48 parts of an aqueous press cake in the same manner as in Example B-1 (1) using a Hensyl mixer. And kneaded. Water was discharged from the downward vent port close to the input port, water vapor spouted from the next vent port, and almost no water vapor was discharged from the vent port close to the die.

  The high-concentration colorant for image recording agent extruded from the die was carried on a cooling steel belt while being cooled, and crushed into coarse particles by a crusher. Furthermore, it supplied to the 3 roll set to 130 degreeC, and knead | mixed. When this was placed on a slide glass, heated and melted and observed with a microscope, all the pigment particles were finely dispersed, and no coarse particles were observed. Further, the transparency of the film on the slide glass plate was further improved. The heat loss by heating at 105 ° C. by an infrared moisture meter was 0.4%.

(2) Manufacture of image recording agent Next, 86 parts of a polyester resin using 11 parts of the high density colorant for image recording agent containing the blue pigment obtained above and 3 parts of an aluminum complex salt negative charge control agent, and a conventional method are used. The mixture was kneaded in accordance with the above, cooled and coarsely crushed, and then finely pulverized with a jet mill and classified to obtain a fine powder of a blue image recording agent of 3 to 10 μm. Colloidal silica was added to this as a fluidizing agent and mixed with carrier magnetic iron powder to obtain a cyan electrophotographic developer. When this was used for copying with a full-color electrophotographic copying machine, a clear cyan image was obtained.

Examples B-11 to 13
In accordance with the method described in Example B-10 (1), each of the materials described in Table B-5 below was used instead of the material used in Example B-10 (1), and each of the high concentrations for the image recording agent was used. Made a colorant. Further, in accordance with the method described in Example B-10 (2), instead of the high density colorant for image recording agent used in Example B-10 (2), for image recording agent described in Table B-6 below. Each color electrophotographic dry developer was made using a high density colorant and the polyester resin used in Example B-10.

  Using the dry developers of Examples B-11, 12 and 13 obtained above, each was copied in a negatively charged two-component full color developer copier, and the clear color images shown in Table B-6 were obtained. It was. In addition, using the four color developers of Examples B-10, 11, 12, and 13, clear color images were obtained. When copied to a transparent polyester film for an overhead projector, an image showing a clear image on the screen was obtained.

Reference Example B-14
(1) Production of high-concentration colorant for image recording agent 300 parts of a copper phthalocyanine blue pigment (PB15: 3) aqueous slurry (pigment content 10%) was put into a stirring tank. Next, 70 parts of a fine powder of polyester resin used in Example B-1 (1) was added and mixed with stirring for 20 minutes. The mixture was filtered with a filter press filter and heated with a box dryer set at 55 ° C. for 20 hours to obtain a water-containing pigment / resin mixture containing 16.7% moisture. This pigment / resin water-containing mixture was charged into a twin-screw extruder (L / D = 52) having three vent ports by a quantitative feeder.

  The heater temperature of the twin screw extruder was set so as to be gradually increased to 60 to 140 ° C. Moisture was discharged from the downward vent port close to the input port for a while after the mixed material was added, and water vapor was actively ejected from the next vent port. There was almost no water vapor from the vent port near the die at the tip of the extruder. The high-concentration colorant for image recording agent extruded from the die was carried on a cooling steel belt while being cooled, and crushed into coarse particles by a crusher. Furthermore, it supplied to the 3 roll set to 130 degreeC, and knead | mixed. When this was placed on a slide glass, heated and melted and observed with a microscope, all the pigment particles were finely dispersed, and no coarse particles were observed. Further, the transparency of the film on the slide glass plate was further improved. The water loss by heating at 105 ° C. by an infrared moisture meter was 0.3%.

(2) Manufacture of image recording agent Next, 86 parts of a polyester resin using 11 parts of the high density colorant for image recording agent containing the blue pigment obtained above and 3 parts of an aluminum complex salt negative charge control agent, and a conventional method are used. The mixture was kneaded in accordance with the above, cooled and coarsely crushed, then finely pulverized with a jet mill, and classified to obtain a fine powder of a blue image recording agent of 3 to 20 μm. Colloidal silica was added to this as a fluidizing agent and mixed with carrier magnetic iron powder to obtain a cyan electrophotographic developer. When this was used for copying with a full-color electrophotographic copying machine, a clear cyan image was obtained.

Examples B-15 to 17
In accordance with the method described in Reference Example B-14 (1), each of the materials shown in Table B-7 below was used instead of the material used in Reference Example B-14 (1), and each of the high concentrations for the image recording agent was used. Made a colorant. According to yet the method described in Reference Example B-14 (2), Reference Example B-14 for image recording material in place of the image recording agent for the high-concentration coloring agent used was noted in Table B-8 below in (2) Using the high-concentration colorant and the polyester resin used in Reference Example B-14, electrophotographic dry developers for each color were prepared.

Using the dry developers of Reference Examples B-15, 16 and 17 obtained above, each was copied with a negative-charge two-component full-color developer copier, and the clear color images shown in Table B-8 were obtained. It was. Further, using the four color developers of Reference Examples B-14, 15, 16, and 17, clear color images were obtained. When copied to a transparent polyester film for an overhead projector, an image showing a clear image on the screen was obtained.

Example B-18
Charge 52.7 parts of propylene oxide adduct of bisphenol A, 33.3 parts of dimethyl terephthalate, and 0.02 part of zinc acetate in a condensation polymerization reactor, and stir and heat for about 6 hours at 230 ° C to 240 ° C. Furthermore, the condensation reaction was continued for 2 hours under reduced pressure to complete the reaction. To the polymerized solution after the reaction, 11 parts of the high density colorant for blue image recording agent obtained in Example B-1 and 3 parts of an aluminum complex salt negative charge control agent were added, and sufficiently stirred and dispersed. The reactor was connected to an extruder, taken out, cooled on a cooled steel belt, coarsely crushed, then finely pulverized with a jet mill, and classified to obtain a fine powder of a blue composition of 3 to 10 μm. Colloidal silica was added to this as a fluidizing agent and mixed with carrier magnetic iron powder to obtain a cyan electrophotographic developer.

  Next, in order to obtain a magenta, yellow, and black electrophotographic developer, the magenta, yellow, and yellow colors obtained in Examples B-2 to 4 were used instead of the high-concentration colorant for the blue image recording agent. Black high-concentration colorants for image recording agents were added after polymerization of the polyester resin, and post-processing was performed in the same manner as above to obtain magenta, yellow, and black electrophotographic developers, respectively. When copying was carried out with a full-color electrophotographic copying machine using the developer of each color described above, a clear full-color electrophotographic printed matter was obtained.

Example B-19
High density colorant for blue image recording agent obtained in Example B-14 (1), 11 parts of aluminum complex negative charge control agent, 38.8 parts of styrene, 30 parts of methyl methacrylate, 17.2 of butyl acrylate Parts, 1 part of azobisisobutyronitrile, and 1 part of polyvinyl alcohol were heated and stirred at 50 ° C. for 15 minutes.

  Next, 700 parts of a 3% polyvinyl alcohol aqueous solution was added dropwise over 30 minutes, and the mixture was sufficiently stirred and suspended. The suspension polymerization reaction was completed by continuing heating and stirring at 70 ° C. to 80 ° C. for 6 hours and 80 ° C. to 90 ° C. for 1 hour. After cooling, it was filtered, washed, dried under reduced pressure, and classified to obtain a fine powder of a blue composition of 3 to 20 μm. Colloidal silica was added to this as a fluidizing agent and mixed with carrier magnetic iron powder to obtain a cyan electrophotographic developer.

  Next, in order to obtain a magenta, yellow, and black electrophotographic developer, Examples B-15 (1), 16 (1), and 17 (17) are used instead of the high-density colorant for the blue image recording agent. Magenta, yellow, and black high-density colorants for image recording agent obtained in 1) are added to the monomers, suspension polymerization is performed in the same manner as described above, and post-processing is performed. A black electrophotographic developer was obtained. When copying was carried out with a full-color electrophotographic copying machine using the developer of each color described above, a clear full-color electrophotographic printed matter was obtained.

[Colorants for general-purpose resins]
According to the present invention as described above, an extruder is used as a kneading machine, and an aqueous presscake of an unagglomerated pigment, an aqueous slurry, a water-wet pigment powder is used as a pigment, and a pigment with a resin -A resin water-containing mixture is prepared, and the pigment-resin water-containing mixture is kneaded in an extruder having a vent port to transfer the pigment from the aqueous phase to the resin phase, and water as a dispersion aid and the vent port By utilizing the water vapor gas, the aggregated pigment particles or the coarse pigment particles in the water-absorbing wet state are disintegrated and scattered, and further kneading is continued in a kneader, so that the pigment does not contain coarse particles and has excellent dispersibility. A pigment / resin composition useful as a colorant for resin is obtained.

  In addition, in the present invention, from the continuity of the kneading process by the extrusion kneader, it can be flexibly produced in response to an increase in demand, which has been difficult with batch kneaders such as kneaders and flashers. By continuing the entire process including the subsequent steps from kneading, the production efficiency is increased, the processing time is shortened, the labor is saved, the rationalization is achieved, and the process is efficiently provided. By using the colorant for resin of the present invention, a molded product excellent in sharpness and transparency is provided.

[Colorant for image recording agent]
According to the present invention as described above, an aqueous presscake or an aqueous slurry of a non-secondarily aggregated pigment is used to remove the pigment from the water without passing through the pigment drying and powdering steps, and without using an organic solvent. By transferring the dry powder pigment from the aqueous phase to the resin phase by the action of water as a dispersion aid, or by kneading with a kneader, the coarse particles of the pigment are transferred from the phase to the resin phase. The colorant for image recording agent and the image recording agent, which are not contained and have excellent dispersibility, are efficiently provided in a continuous process using an extrusion kneader. The color of a copy image by an image recording agent using the colorant for image recording agent of the present invention is excellent in sharpness and transparency, and is suitable for copying not only on paper but also on a film for an overhead projector.

Claims (8)

The water-containing pigment and the heat-meltable resin have a first moisture content ratio [{water / (water, pigment and heat-meltable resin)} × 100] of 4 to 25% by mass, 2 is continuously fed into an extrusion kneader having at least one vent port under the condition that the content ratio [{water / (water and pigment)} × 100] is 12% by mass or more and 30% by mass or less. Kneading at a temperature equal to or higher than the melting temperature of the resin, and discharging the separated water and remaining water vapor from the vent port while kneading at a temperature equal to or higher than the melting temperature of the resin, so that the pigment is contained in the molten resin. A method for producing a pigment / resin composition, which comprises dispersing. The pre-Symbol pigments and heat-meltable resin, (1) heating and / or reduced pressure to mix after removal of the water, (2) mixed with heating and / or reduced pressure to remove water, or (3) After mixing, the moisture is removed by heating and / or decompression, and the first content ratio of moisture in the mixture of the pigment and the heat-meltable resin [{water / (water, pigment and heat-meltable resin)} × 100] 4 to 25% by mass and the second moisture content [{water / (water and pigment)} × 100] is 12% by mass or more and 30% by mass or less. The method for producing a pigment / resin composition according to claim 1, which is continuously charged.   The method for producing a pigment / resin composition according to claim 1, wherein the heat-meltable resin is at least one polymer or at least one polymer alloy.   The method for producing a pigment / resin composition according to any one of claims 1 to 3, wherein the pigment is a chromatic, black or white organic or inorganic pigment or an extender pigment.   The method for producing a pigment / resin composition according to any one of claims 1 to 4, wherein the extruder is a single-screw, twin-screw or multi-screw extruder having at least one vent port.   The obtained pigment / resin composition is further kneaded by a kneader, and further pelletized or sheeted by a continuous granulator or a continuous sheeting machine as necessary. A method for producing a pigment / resin composition.   The method for producing a pigment / resin composition according to claim 6, wherein the kneader is a two-roll, three-roll, kneader, continuous open roll, or extruder.   The pigment / resin composition according to any one of claims 1 to 7, further comprising a dispersant, an antioxidant, a light stabilizer, an ultraviolet absorber, an infrared absorber, an antistatic agent, or a mixture thereof. Method.