JP4713821B2 - Method for producing particulate photocurable resin, particulate photocurable resin and surface treatment method for article - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a fine particle photocurable (active energy ray curable) resin, a fine particle photocurable resin, and a surface treatment method for an article using the same, and more specifically, rationalized for mass production. Fine particles useful for surface treatment of articles as a constituent material of powder coating materials, slurry coating materials, image recording materials, printing inks, etc. An object is to provide a photocurable resin.
[0002]
[Prior art]
Conventionally, powder coatings are obtained by melt-extruded resins obtained by measuring, mixing and kneading paint resins and pigments or further internal additives such as charge control agents to dissolve or disperse the above components in the resin. After being coarsely pulverized with a crusher or the like, finely pulverized with a fine pulverizer such as a jet mill, and then coarsely and finely ground with an air classifier.
[0003]
In the above production method, the resin pulverization, the measurement of the resin and additives for each batch, the production process such as mixing with a tumbler or a Hensyl mixer, etc., supply the resin to the extruder in Patent Document 1, It has been proposed that improvements can be made by supplying pigments to an extruder via an automatic metering device and kneading the pigments and a molten resin in the extruder.
[0004]
[Patent Document 1]
JP 11-49864 A
[0005]
[Problems to be solved by the invention]
However, the above-mentioned crushing and granulating method has a drawback that a fine pulverizer such as a jet mill or an air classifier used is very expensive. In addition, recently developed photo-curing resins, when used as a resin for powder coatings, have superior leveling properties compared to the use of thermosetting resins, while for conventional powder coatings. Compared to the production of resin fine particles, it is necessary to manage the production conditions more strictly and costly in order to improve the microparticulation process of the photocurable resin, prevention of blocking of the obtained fine particles, and preservation of the fine particles. It has become.
[0006]
For this purpose, the above-mentioned photocurable resin and other necessary components need to be controlled in the pulverizer, the particle size of the fine particles must be reduced, and the particle size distribution must be narrowed. It has become difficult to manufacture products of this type efficiently and inexpensively. Furthermore, when the production conditions of the photocurable resin fine particles cannot be set by existing equipment, there is a problem in terms of economy, such as the introduction of new equipment is necessary. In addition, fine particles made of a photocurable resin by the crushing granulation method are crushed particles having an irregular particle shape, and the distribution of the surface charge of these fine particles is not uniform. Compared to spherical resin fine particles obtained by a legal method or the like, a lot of fine powders that are inappropriate as a resin for powder coatings are generated and remain, which is uneconomical in terms of material costs.
[0007]
The present inventors have intensively studied to provide a fine-particle photocurable resin that solves such problems, enables mass production, has a uniform particle shape, and has uniform properties in an economical and rational manner. As a result of proceeding, the photo-curable resin is made into a molten state, which is insoluble in the resin. Sex medium It has been found that spherical particulate photocurable resin can be obtained by forming fine droplets in the body, and subsequently cooling and solidifying the droplets, followed by filtration, washing and drying. In addition, this method is rationalized because it does not require the above-described conventional various pulverization steps and classification steps, and according to this method, a homogeneous spherical fine particle photocurable resin powder (for example, an ultraviolet curable type) is used. It was found that the powder coating) can be mass-produced and is economically superior. Based on such findings, the present inventors have further studied for the purpose of providing a particulate photocurable resin, particularly a particulate photocurable resin for powder coatings, and as a result, the present invention has been completed. In the present invention, “insoluble” Sex liquid "Medium" or "insoluble Sex medium “Body” means a liquid or gas that does not substantially dissolve the photocurable resin.
[0008]
[Means for Solving the Problems]
That is, the present invention provides a step of bringing a photocurable resin having heat melting property into a molten state, an insoluble material that does not dissolve the molten resin. Sex medium A step of forming the molten resin in the body into fine droplets, and a step of cooling and solidifying the fine droplets. And the insoluble medium is any glycol selected from ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, mono- and dialkyl ether derivatives of the glycol, mono- and di-alkyl ether derivatives of the glycol, and Dicarboxylic acid ester derivatives, monoalkyl ether monocarboxylic acid ester derivatives of the glycol, glycerin, diglycerin, polyglycerin, silicone oil, mineral terpenes, kerosene, white kerosene, hydrocarbon solvents, higher fatty acid esters, higher fatty acid triglycerides or vegetable oils Is at least one selected from the group consisting of There is provided a method for producing a particulate photocurable resin characterized by the above.
[0009]
In the present invention, the melt viscosity of the photocurable resin is 1 to 500 Pa · s at a temperature of 80 ° C. to 180 ° C .; the melt viscosity of the photocurable resin is 1 at a temperature of 90 ° C. to 160 ° C. ~ 100 Pa · s; insoluble in the process of forming fine droplets Sex medium The body temperature is 70 ° C to 200 ° C, and insoluble in the process of cooling and solidifying Sex medium Body temperature is −10 to 20 ° C .; insoluble in the process of forming fine droplets Sex medium The temperature of the body is 100 ° C to 160 ° C, and the process of solidifying by cooling is insoluble Sex medium The body temperature is 0 to 10 ° C .; and in the step of forming fine droplets, the molten photocurable resin is insoluble. Sex liquid It is preferable to form fine particles by dispersing in an emulsion in the medium.
[0010]
In the present invention, in the step of forming fine droplets, the heat-meltable photocurable resin has an aromatic ring or an alicyclic ring in the structure and has a photocrosslinkable double bond. The glass transition point of the heat-meltable photocurable resin is 40 ° C. or higher and the softening point is 80 ° C. to 150 ° C .; the weight average molecular weight of the heat-meltable photocurable resin is 1,000. Preferably ˜50,000; and the light is an electron beam, ultraviolet or near ultraviolet.
[0011]
The present invention also provides a particulate photocurable resin produced by the method of the present invention. The particulate photocurable resin is suitable for paints, image recording materials, or printing materials. In the present invention, “photocurability” means electron beam curable, ultraviolet curable, or near ultraviolet curable.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described in more detail with reference to preferred embodiments. The photocurable resin used in the present invention is a resin that is solid at room temperature and is heat-meltable. The resin may contain additives such as coloring pigments, extender pigments, charge control agents, waxes, cross-linking agents, light stabilizers, and ultraviolet absorbers. Further, when the resin is of an ultraviolet curable type, the photoinitiator can be uniformly dispersed or dissolved.
[0013]
In the present invention, the method of micronizing the photocurable resin is to make the photocurable resin in a molten state and insoluble the molten resin. Sex medium It is characterized by forming fine droplets in the body, then cooling and solidifying, and does not require the resin crushing and classification steps as in the prior art. In the present invention, examples of a preferable method for obtaining the fine particles include the following methods.
(1) A photocurable resin in a molten state is insoluble in the resin Liquid A method in which an emulsion is dispersed in a medium and then cooled to solidify the dispersed fine particles (hereinafter referred to as “emulsion fine particle formation method”).
[0014]
In the step of making the photocurable resin in the molten state into fine droplets, it is necessary to keep the photocurable resin in the molten state as low as possible, and for that purpose, at a temperature in a range where the resin does not decompose, Further, it is desirable to completely melt the resin by raising the temperature further than the softening temperature of the resin. Further, in the cooling and solidifying step of the particulate droplets, it is desirable to cool these particulate droplets as low as possible in order to cool and solidify the generated particulate droplets without fusing them. For example, in the step of forming fine droplets of photocurable resin, the insoluble Sex medium The body temperature is about 70 ° C. to 200 ° C., preferably about 100 ° C. to 160 ° C., and is about −10 ° C. to 20 ° C., preferably about 0 ° C. to 10 ° C. in the solidification step.
[0015]
When making the photocurable resin into fine droplets, in order to prevent fusion of the produced fine droplets, insoluble Sex liquid It is also preferable to add colloidal silica, inorganic salts, polymer protective colloids or the like as a fusion inhibitor to the medium. Moreover, after the fine particles of the produced photocurable resin are solidified, they are filtered, washed and dried. If undesirably coarse particles, fine powders or aggregated fine particles are produced during these steps, they are It is also preferable to use a crusher or a crusher for crushing, or to separate and remove coarse particles and fine powder using an automatic sieve or a classifier. The above-mentioned melted photocurable resin in the form of fine droplets, solidification, crushing, classification, etc. are commonly applied to the methods described below. The photocurable resin may be melted under normal pressure or under pressure.
[0016]
Insoluble used in each of the above methods Sex liquid The medium is a solvent that does not substantially dissolve the photocurable resin. Specifically, for example, glycols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol, their mono and dialkyl ethers, mono and dicarboxylic esters, monoalkyl ether monocarboxylic esters, and the like Derivatives of glycerin, diglycerin, polyglycerins; silicone oils; mineral terpenes, kerosene, white kerosene, “Isopar” (manufactured by Exxon Chemical), “shell sole” (manufactured by Shell Japan), “hyzol” (Japan) Hydrocarbon solvents having a trade name such as Petrochemical Co .; higher fatty acid esters, higher fatty acid triglycerides, vegetable oils and the like.
[0017]
Each of the above methods will be described in detail below.
Examples of the “emulsion fine particle method” of (1) include the following modes.
(A) Insoluble Sex liquid A method in which a photocurable resin in a molten state in a medium is dispersed into fine droplets by high-speed stirring or impact force, and cooled and solidified to form fine particles. In this method, a strong shear stress is applied to break and disperse the melt of the photocurable resin. Preferable apparatuses include conventionally used emulsifiers such as a high-speed stirring emulsifier, a high-pressure collision emulsifier, a pressure-resistant high-speed stirrer, and an extruder.
[0018]
The rotation speed of the stirring blade in these apparatuses is the particle size required for the fine particles of the resulting photocurable resin, the melt viscosity of the photocurable resin, and the insolubility. Sex liquid Since it varies depending on the viscosity of the medium and cannot be specified in general, preliminary examination is necessary each time. For example, when the particle size required for the photocurable resin fine particles is 7 μm to 10 μm, the rotational speed is about 6,000 to 20,000 rpm, preferably about 7,000 to 15,000 rpm. It is preferable to proceed the micronization process while confirming the particle size of the generated photocurable resin fine particles with an optical microscope or a particle size distribution measuring instrument.
[0019]
(B) Insoluble melted photocurable resin through pores of porous body Sex medium A method of discharging into the body, dispersing in fine droplets, cooling and solidifying. As the porous body used in this method, various porous films having openings capable of preparing fine particles having a desired particle diameter are used. The physical properties, strength, and chemical robustness of the porous membrane material do not damage the particulate droplets and are not soluble. Sex liquid It is an inert material that is chemically stable and inert with respect to the medium and the melted photo-curing resin, and should not be deformed or broken under heating conditions under normal pressure or under pressure. Specific examples include a porous stainless steel film, a porous brass film, a stainless steel wire mesh, a brass wire mesh, a porous glass film, a shirasu porous glass, and a porous ceramic.
[0020]
The size of the opening of the porous film is not particularly limited, and the melt viscosity, discharge speed, and insolubility of the photocurable resin melt are not limited. Sex liquid Although it depends on the viscosity of the medium, the fine particles generated from the melt of the photocurable resin are generally larger than the aperture of the opening of the porous film, so the opening is slightly smaller than the particle size required for the photocurable resin fine particles. Use one with a part. For example, the size of the opening is 1/2 to 1/5, preferably 1/3 to 1/4 of the particle size of the resulting photocurable resin fine particles. When the average particle size of the resulting photocurable resin fine particles is 7 to 10 μm, a diameter of about 1.5 to 3 μm is desirable. In this case, in combination with the above method (a), a method using a high-speed stirring emulsifier equipped with a porous stainless steel cylinder around the rotor blade, or a high-speed stirring emulsifier or a high-pressure impact emulsifier is used in advance. Then, it may be coarsely emulsified and dispersed.
[0021]
In the “emulsion microparticulation method” of (1) above, in order to reduce the viscosity of the photocurable resin in the molten state or to make it easy to make the droplets small, insoluble Sex liquid A high boiling point solvent compatible with the liquid may be added to the medium. The high boiling point solvent may be a solvent that dissolves the photocurable resin, or may be a solvent that does not dissolve. Insoluble Sex liquid When a medium is used, the method (1) results in a multistage emulsion.
[0022]
The photocurable resin fine particles obtained by the above methods are insoluble. Sex medium Due to the surface tension of the fine droplets of the photocurable resin in the body, it becomes spherical or elliptical, and the particle size of the fine particles can be controlled in advance by setting conditions and processes. It has a uniform and uniform shape. Therefore, the photocurable resin fine particles obtained by the method of the present invention are used in powder coatings and the like, and the electrical properties such as chargeability and the properties as a surface decorating material are the same as those obtained by crushing and granulating in the prior art. It is superior to those using non-uniform fine particles.
[0023]
The photocurable resin having heat melting property used in the present invention has a double bond that crosslinks with light at the terminal of the condensation polymerization resin or addition polymerization resin conventionally used in various applications as described above. A photocurable resin or a mixture thereof is used. In particular, a condensation polymerization resin having a hydrocarbon ring exhibits a high glass transition point (that is, a solid at room temperature) even at a relatively low molecular weight due to the crystallinity of the hydrocarbon ring, and thus has a relatively low molecular weight. It has a low melt viscosity and is a very preferable resin. Further, maleimide compounds shown in JP-A Nos. 2000-273361 and 2001-262010 are also useful, and propenyl ether group-containing photocationic curable resins shown in JP-A No. 10-183024 are also within the above range. It can be used within the range shown.
[0024]
As the above condensation polymerization resins having a high glass transition point and a low melt viscosity, polyester resins and acrylic resins having a hydrocarbon ring such as an aromatic ring such as a benzene ring or a naphthalene ring or an alicyclic ring such as a cyclohexane ring are used. A modified urethane resin or the like is preferable. A polyester resin having an aromatic ring or an alicyclic ring is a polyester resin obtained using a diol having these rings and / or a dicarboxylic acid having those rings as a main raw material. Further, the acrylic-modified urethane resin having an aromatic ring or an alicyclic ring has at least a hydroxyl group-containing polyester resin having these rings, a polyisocyanate having those rings, a hydroxyl group at the terminal, and a polymerizable acrylate group. It is an acrylic-modified urethane resin obtained using a compound having one by one as a main raw material.
[0025]
Examples of the diol having an aromatic ring or alicyclic ring include alkylene (C2-C4) oxide adducts of bisphenols such as bisphenol A, bisphenol F, and bisphenol S, hydrogenated products thereof, p-xylene glycol, Bis (hydroxyethoxy) benzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and the like can be mentioned.
[0026]
Examples of the dicarboxylic acid having an aromatic ring or alicyclic ring include terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, cyclohexene-1,2-dicarboxylic acid, methylnadic acid and the like and lower Examples include alkyl esters, acid halides and acid anhydrides.
[0027]
Examples of the aliphatic dicarboxylic acid that can be used together with the diol having an aromatic ring or alicyclic ring include maleic acid, fumaric acid, adipic acid, sebacic acid, azelaic acid, and the like. Examples of the aliphatic diol that can be used with the dicarboxylic acid having a cyclic ring include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, diethylene glycol, and dipropylene glycol.
[0028]
The polyisocyanate used in the production of the acrylic-modified urethane resin is preferably one having an aromatic ring or an alicyclic ring, but may be an aliphatic polyisocyanate. Representative examples include 2-methylpentamethylene-1,5-diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene-1,6-diisocyanate, 4,4-methylene-bis (cyclohexyl isocyanate), norbornane diisocyanate, 3,3, Examples include 3-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane (IPDI). Moreover, you may have the isocyanurate, burette, and allophanate structure which several isocyanate groups react and produce.
[0029]
When synthesizing a polyester resin having these aromatic or alicyclic rings, acrylic acid, methacrylic acid, glycidyl acrylate, glycidyl methacrylate, etc. are combined to impart photocurability to the polyester resin, and the glass transition point is about 40. A photo-curable resin that is solid at room temperature and has a sharp melting property with a narrow melting temperature range, with a softening point of about 80 ° C. to 150 ° C., preferably 90 ° C. to 130 ° C. Is suitable for applications such as powder coatings. Moreover, the preferable weight average molecular weight of these resin is 1,000-50,000, Preferably it is 3,000-10,000.
[0030]
When synthesizing an acrylic modified urethane resin having an aromatic ring or an alicyclic ring, the acrylic modified urethane resin is photocured by combining a compound having at least one hydroxyl group and at least one polymerizable acrylate group at the terminal. Sex can be imparted. Examples of such compounds include hydroxyethyl acrylate (HEA), hydroxypropyl acrylate, and glycerol diacrylate. The acrylic modified urethane resin obtained by synthesis has a glass transition point of about 40 ° C. or higher, particularly preferably 45 ° C. to 65 ° C., and a softening point of about 80 ° C. to 150 ° C., preferably 90 ° C. to 130 ° C. A sharp and melt room temperature solid photocurable resin with a narrow temperature range is suitable for applications such as powder coatings. Moreover, the preferable weight average molecular weights of these resins are 1,000 to 50,000, preferably 3,000 to 10,000.
[0031]
In the above-described method for producing the photocurable resin fine particles of the present invention, it is important that the photocurable resin is melted, and that the resin in the molten state has a viscosity suitable for each microparticulation method, that is, a melt viscosity. . The melt viscosity of the photo-curable resin may vary depending on the measurement method. In the present invention, the “viscorn” is designed and manufactured based on the method of measuring the melt characteristics of the hot-melt resin in the cone plate. CV-1S ”(manufactured by Tokai Yagami Co., Ltd.) and melt viscosity (Pa · s) measured under the following measurement conditions.
[0032]
In addition, the melt viscosity of the photocurable resin largely depends on the temperature at which the melt is melted. However, the melt viscosity is also affected by the additive added to the resin, and the additive added. The numerical value varies depending on the type and amount added. Therefore, in making the photocurable resin into fine particles, a photocurable resin containing no additive is prepared. For example, the melting temperature and the extrusion speed of the resin are changed by the above-mentioned “Biscorn CV-1S” to melt the photocurable resin. Measure the viscosity. The melt viscosity of the photo-curable resin varies depending on the method of atomization and cannot be generally specified, but the melt viscosity is a temperature that falls within a viscosity range of about 1 to 500 Pa · s, preferably 1 to 100 Pa · s. It is preferable that the photocurable resin melted under the temperature condition is made into fine particles according to the above-described method. As temperature conditions, it is about 80 to 180 degreeC, for example, Preferably it is 90 to 160 degreeC.
[0033]
Although a photocurable resin composition is manufactured by adding an additive to above-described resin, a manufacturing method is not specifically limited. For example, as a preferable production method, there is a method proposed in Japanese Patent Application Laid-Open No. 11-49864, in which the resin is supplied to an extruder and the additive is extruded through an automatic metering device. This is a manufacturing method in which an additive and a molten resin are kneaded in an extruder.
[0034]
Further, in the case where the resin is a resin by condensation polymerization reaction such as a photo-curable polyester resin, for example, a streamlined manufacturing method as proposed in JP-A-11-46894 can be applied. . In this method, the additive is dissolved in each stage of the resin synthesis, that is, in the raw material components, in the resin during the polymerization reaction, in the molten resin after the completion of the polymerization, or in the molten resin taken out from the reaction kettle. Or disperse. If the polymerization reaction is not completed, the reaction is further advanced to complete the polymerization. The photocurable resin obtained by these methods can be subsequently made into fine particles by the method as described above.
[0035]
As a method for producing fine particles of a photocurable resin containing an additive in the present invention, in particular, the photocurable polyester resin after the synthesis reaction is kept in a molten state, or the resin is passed through an automatic metering device in a fine powder state. Then, a method is preferably used in which the additive is supplied to the extruder and the additive is supplied to the extruder via an automatic metering device so that the additive is internally added to the resin. Subsequently, the obtained photocurable resin composition was dissolved in the above insoluble. Sex medium It is the most rational and economical in the manufacturing process to make fine particles in the body.
[0036]
Additives used in the present invention are colorants and extenders, flow regulators, antifoaming defoamers, photoinitiators, charge control agents, ferromagnetic materials, waxes, crosslinkers, light stabilizers, UV absorbers Agents and various resins. The types and amounts of these additives are not particularly limited except for the photoinitiator, but are used within a range not exceeding the amount of the photocurable resin.
[0037]
In the case of an ultraviolet curable resin using a photoinitiator, the use amount of the photoinitiator is preferably 0.5 to 10% by mass of the resin, and the colorants are added in a range not inhibiting the curability. Is selected. Examples of the colorant include pigments selected from chromatic or black oil-soluble dyes, disperse dyes, organic pigments, carbon black pigments and inorganic pigments, fine ferromagnetic materials, white organic pigments and inorganic pigments. .
[0038]
Examples of the colorant include azo pigments, high molecular weight azo pigments, azo pigments containing an azomethine group, azomethine pigments, anthraquinone pigments, phthalocyanine pigments, perinone / perylene pigments, indigo / thioindigo pigments, dioxazine pigments, quinacridone pigments, isoindoindones. Examples include linone pigments, isoindoline pigments, diketopyrrolopyrrole pigments, quinophthalone pigments, metal complex pigments, organic pigments such as aniline black, inorganic pigments such as iron oxide pigments, composite oxide pigments, and titanium oxide pigments. Further, metal powders typified by aluminum, bright pigments by treatment of mica, colored cross-linked plastic fine particles, and the like are also provided as colorants.
[0039]
Other additives include, for example, extender pigments such as precipitated barium sulfate, calcium carbonate, and clay; flow regulators; antifoaming defoamers: 1- [4- (2-hydroxyethoxy) -phenyl]- Starting with 2-hydroxy-2-methyl-1-propan-1-one (trade name; Irgacure 2959) and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (trade name; Irgacure 819) Known UV-curing photoinitiator; when the fine particles of the present invention are applied to an electrophotographic developer, a charge control agent as an internal additive such as a salicylic acid metal complex, an azo dye metal complex, a cationic compound, etc. It is done.
[0040]
In addition, when the fine particles of the present invention are applied to an electrophotographic developer, a conventionally known fine ferromagnetic material selected from, for example, black, brown, or reddish brown magnetic iron oxide and magnetic metal is used as the ferromagnetic material. Can be mentioned. Similarly, when the fine particles of the present invention are applied to an electrophotographic developer, waxes include higher fatty acid ester stearyl palmitate, stearyl stearate, behenyl behenate, behenyl stearate, stearyl behenate, hydroxystearic acid. Conventionally known waxes such as glyceride, etc .; paraffin waxes; polyethylene oligomers, ethylene copolymer oligomers, polypropylene oligomers and the like can be mentioned. Moreover, as an additive in the other use of the fine particles of the present invention, a light stabilizer, an ultraviolet absorber, and various resins are used as necessary. The use ratio of these additives may be in a known range.
[0041]
In addition, when the melt viscosity of the photocurable resin used in the present invention is low, the powder paint or dry developer obtained using the photocurable resin fine particles of the present invention may be paper, wood, plastics, etc. Excellent properties such as excellent fixability, excellent color development, sharpness, and smoothness of coatings when coatings and images are formed on substrates such as iron, aluminum, magnesium and other metal plates and moldings To demonstrate.
[0042]
The photocurable resin fine particles of the present invention are useful in a conventionally known application using known fine particles. For example, as described above, printing ink, electrostatic powder coating, fluid immersion powder coating, slurry paste coating It is useful as a constituent material for image recording materials such as surface treatment agents such as electrophotographic dry developers and ink jet printing inks. Printing, painting, image recording, etc. are performed using these printing inks and paints. Article surface treatment can be performed.
[0043]
【Example】
Next, an Example is given and this invention is demonstrated concretely. In the text, “part” or “%” is based on mass.
[0044]
Example 1 (Emulsion micronization method)
Resin: Uvecoat3003 ^{* 1} 80.6 parts
Resin: Uvecoat9010 ^{* 2} 14.2 parts
Photoinitiator: Irugacure2959 ^{* 3} 2.8 parts
Flow regulator: ResiflowP67 ^*Four 1.1 parts
Matting agent: Ceraflour969 ^*Five 1.3 parts
* 1, * 2; UCB photocurable (ultraviolet curable) resin
* 3: Ciba Geigy
* 4: Entron
* 5; Byk-Chemie
[0045]
The above ingredients were blended and put into a hexyl mixer and mixed uniformly. The obtained mixture was filled in an extruder, heated to 90 ° C. and extruded. The viscosity at 90 ° C. was 30 Pa · s with biscorn CV-1S. Insoluble for making fine particles of this molten resin Sex liquid Ethylene glycol was selected as the medium, and the temperature of ethylene glycol was set to 110 ° C. In a stainless steel container equipped with a heating device and a stirring device, 300 parts of ethylene glycol and 100 parts of an ethylene glycol dispersion of 20% silica were charged and stirred and dispersed.
[0046]
Thereto, about 500 parts of the ultraviolet curable resin composition extruded from the extruder at 90 ° C. was added and stirred uniformly at a temperature of 110 ° C. to finely disperse the melt. On the other hand, 100 parts of ethylene glycol and 100 parts of an ethylene glycol dispersion of 20% silica were placed in a stainless steel vessel equipped with a heating device and a high-speed stirrer, and heated to 110 ° C. to prepare an outer bath.
[0047]
The melted ethylene glycol dispersion of the ultraviolet curable resin composition prepared above was injected into an outer bath under high-speed stirring through a vitreous porous plate having an average diameter of 2.7 μm under pressure. The molten ultraviolet curable resin composition was dispersed into the outer bath in the form of droplets by the porous plate. While continuing high speed stirring of the outer bath, the state of atomization was appropriately observed with a microscope, and after confirming that the particle size of most of the fine particles became 5 to 10 μm, the outer bath was cooled. After the temperature dropped to 10 ° C., the solidified blue fine particles were filtered off, sufficiently washed with water, and dried to obtain spherical, uniform UV curable resin fine particles of the present invention having an average particle diameter of about 8 μm.
[0048]
0.2 parts of fine powder silica as a flow control agent was added and mixed per 100 parts of the obtained ultraviolet curable resin fine particles to obtain a powder coating composition comprising the ultraviolet curable resin fine particles of the present invention.
[0049]
The obtained powder coating composition comprising ultraviolet curable resin fine particles is applied to a vinyl chloride resin tile with 20 g per square meter with a powder coating gun (ONODA GX-107), and the surface is heated to 120 ° C. with a far-infrared lamp. And heated to 800 mj / cm with 120 W / cm high pressure mercury lamp (ozone ant) ² And cured by irradiation. This coating film was more excellent in smoothness than the coating film of the powder coating material by a normal production method that was pulverized and classified to an average of 30 μm.
[0050]
【The invention's effect】
In the past, when producing fine particles of photocurable resin, the so-called crushing granulation method in which fine particles were pulverized with a fine pulverizer such as a jet mill and coarse particles and fine powders were cut with a classifier was the mainstream. The machine is very expensive, and it is difficult to manufacture the target product efficiently and inexpensively due to the advanced manufacturing conditions for heat-resistant fusion of fine particles recently required, the reduction of throughput, and the decrease in productivity. It has become increasingly difficult. In addition, the fine particles produced by crushing granulation are irregular crushing particles, the particle size distribution is uneven, and many residual fine powders with insufficient performance as fine particles are generated, which is uneconomical. .
[0051]
However, according to the present invention described above, the photocurable resin is in a molten state in a poor solvent or insoluble. Sex medium By making it fine in the body, solidifying by cooling, and filtering and drying as necessary, it is useful especially for powder coatings and electrophotographic dry developers, without requiring various conventional pulverization and classification steps. It is possible to mass-produce fine particles made of a homogeneous photo-curing resin having a uniform shape and properties in an economical and streamlined manufacturing process.
[0052]
In addition, by adjusting the photocurable resin suitable for each application to a predetermined particle size, the photocurable resin fine particles of the present invention can have various surface treatment agents such as printing ink, electrostatic powder coating, Useful for the production of image recording materials such as fluidized immersion powder coatings, slurry paste coatings, image recording materials, resin colorants, paints, surface treatment agents such as printing inks, dry developers for electrophotography, and inks for ink jet printing. is there.

Claims (13)

Step of the photo-curable resin having a heat-meltable melted, process the resin in the molten state in an insoluble medium body which does not dissolve the resin in the molten state and particulate droplets and the fine particle-like droplets, It has a step of cooling and solidifying the, and the insoluble medium is ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, polyethylene glycol, or glycol selected from polypropylene glycol, or mono- and dialkyl ethers of the glycols Derivatives, mono- and dicarboxylic acid ester derivatives of the glycol, monoalkyl ether monocarboxylic acid ester derivatives of the glycol, glycerin, diglycerin, polyglycerin, silicone oil, mineral terpenes, kerosene, white kerosene, hydrocarbon solvents, higher grades Fatty acid esters, method for producing a particulate photocurable resin, wherein at least any one selected from the group consisting of higher fatty acid triglyceride or a vegetable oil.   The method for producing a particulate photocurable resin according to claim 1, wherein the melt viscosity of the photocurable resin is 1 to 500 Pa · s at a temperature of 80 ° C to 180 ° C.   The method for producing a particulate photocurable resin according to claim 1, wherein the melt viscosity of the photocurable resin is 1 to 100 Pa · s at a temperature of 90 ° C to 160 ° C. Temperature of an insoluble medium of step a particulate droplets are 70 ° C. to 200 DEG ° C., a temperature of an insoluble medium of step of cooling solidification, according to claim 1 is -10 to 20 ° C. Manufacturing method of particulate photocurable resin. Temperature of an insoluble medium of step a particulate droplets are 100 ° C. to 160 ° C., a temperature of an insoluble medium of step of cooling solidification, particles of claim 1 which is 0 ° C. For manufacturing a photocurable resin. In the step of the particulate droplets, the molten photocurable resin, the manufacturing method of the particulate light-curable resin of Claim 1 which is dispersed in the emulsion form in an insoluble liquid medium and particulate.   The method for producing a particulate photocurable resin according to claim 1, wherein the heat-meltable photocurable resin has an aromatic ring or an alicyclic ring in the structure and has a photocrosslinkable double bond. .   The method for producing a particulate photocurable resin according to claim 7, wherein the heat-meltable photocurable resin has a glass transition point of 40 ° C or higher and a softening point of 80 ° C to 150 ° C.   The method for producing a particulate photocurable resin according to claim 7, wherein the heat-meltable photocurable resin has a weight average molecular weight of 1,000 to 50,000.   The method for producing a particulate photocurable resin according to claim 1, wherein the light is an electron beam, ultraviolet rays, or near ultraviolet rays.   A particulate photocurable resin produced by the method according to any one of claims 1 to 10. The particulate photocurable resin according to claim 11, which is used for a paint, an image recording material, or a printing material. A surface treatment method for an article, wherein the article is surface-treated with any one of a paint, an image recording material, and a printing ink containing the particulate photocurable resin according to claim 12.