KR100754319B1 - Method for treatment of Permanent antistatic and curing by a continuous UV cure to a injection molded part - Google Patents

Abstract

The present invention is applied to the surface of the injection molding conductive polymer and UV-curable binder as an active ingredient, the antistatic solution is applied to the surface, dried, and cured to form an antistatic layer excellent in coating properties without any solvents, such as alcohol, to prevent permanent charge on the injection molding In the invention of a continuous ultraviolet curing device that imparts performance, more specifically, a device for cleaning the contaminants or release agent on the surface of the injection molding, a device for applying a coating liquid, a device for drying the applied antistatic liquid and a UV curing device The present invention relates to a continuous coating apparatus that continuously connects and imparts permanent antistatic property to an injection molding inline. Using the apparatus and techniques of the present invention it is possible to obtain injection molded articles having permanent antistatic properties without any wiping with alcoholic solvents on the injection molded product surface.

Description

Method for treatment of Permanent antistatic and curing by a continuous UV cure to a injection molded part

The present invention relates to a method for forming a permanent antistatic layer on the surface of an injection molded article, a permanent antistatic liquid composition which can be coated on the surface of various injection molded articles, and an antistatic injection product prepared therefrom. More specifically, the present invention provides a method for forming a permanent antistatic layer on the surface of an injection molded product by applying, drying and curing the permanent antistatic liquid composition to the surface of an injection molded product, such as a large backlight unit transport tray, and the like. It relates to an injection molded product having a permanent antistatic layer.

Each product made of a polymer can not prevent the static damage caused by the electrostatic charge formed on the surface because the polymer is originally electrically insulating. In order to impart antistatic properties to such polymer products, a separate prescription is required. In the case of a film or sheet, an antistatic liquid may be applied to the surface to provide an antistatic property, or an antistatic component may be mixed with a polymer. use.

However, in the case of injection molding, in order to impart antistatic property, a method different from the method of imparting antistatic property to a conventional film or sheet polymer should be used. That is, in the case of film-type polymers, in order to provide antistatic properties to the surface, an antistatic layer of several microns or less may be easily formed on the surface by using a method such as gravure method, roll coating method, bar coater coating method, and the like. When the antistatic layer is formed on the surface of the sheet, the semiconductor or precision electronic component transport container may be manufactured by a method such as vacuum molding. (Reference: Republic of Korea Patent Application No. 2001-20546, "Antistatic conductive polymer coating composition and packaging material", Republic of Korea Patent Application 2003-20837, "Method for producing a conductive sheet having an antistatic layer of excellent physical properties").

For example, in the case of a polymer product having a very smooth surface such as a film, sheet or plate, one or more of extruded products or immediately after extrusion, gravure coating, roll coating, bar coater coating, or flow coating The method can be used to easily form an antistatic layer on the surface.

However, in the case of injection-molded products, unlike the sheet polymer products, the surface is not smooth and the curvature is very severe. In some cases, the shape of the front and back surfaces is very different. An antistatic layer cannot be obtained.

Particularly in the case of injection molded products, a release agent is used to improve mold release from the mold during injection molding. The release agent is essentially a coating film such as an antistatic liquid coating property, that is, wettability of an antistatic liquid and adhesion to the surface of an underlying injection molding product. It acts as a detrimental property. In addition, in the case of the impregnation method, the thickness of the antistatic liquid applied to the surface of the injection molding is inevitably thick. In the case of thickening the coating to improve the physical properties, the viscosity of the antistatic liquid must be controlled, as well as transporting the injection molding. When recycled into containers and used several times, alcoholic solvents can be used to wipe off contaminants on the surface during handling by the handler. Therefore, the antistatic layer formed on the injection surface should not be wiped off by these alcoholic solvents. In case of use, the coating film property of the antistatic layer formed on the surface is firm, so that the surface of the antistatic layer should not be damaged due to the scratching of the laminated polymer product. The condition must be met.

Looking at the existing patented technology for imparting permanent antistatic properties of polymer injection molded articles, most of them are limited to general thermosetting methods. For example, a description of the surface coating method of the shipping tray, a semiconductor integrated circuit chip transport container (Reference: Republic of Korea Patent Registration No. 313982, "Coating Method of Direct Circuit Chip Shipping Tray"), the surface of the injection molded shipping tray The conductive polymer and binder were used as active ingredients, and antistatic liquids in which various additives were mixed or dispersed were prepared, and then applied to the surface of the injection molded product and dried to obtain a permanent antistatic layer on the surface by thermosetting. . In addition, an example of application of an antistatic liquid to an injection molded article using a conductive polymer is described by Bayer, Germany (see US Patent No. 5,035,926, "Method of imparting antistatic properties to a substrate by coating the substrate with a novel polythiophene"). (Bayer, Germany), and a method of thermally drying a polyethylenedioxythiophene, a conductive polymer of Stark, Germany, is mixed with an organic binder and applied to the surface of an injection molded article. In addition, according to the Japanese Nagase patented technology, it is possible to obtain antistatic properties by mixing polyethylene dioxythiophene, a conductive polymer of Germany Stark, with a binder and coating the surface of the injection molded product. (Reference: Korean Patent Application No. 2002-36795, "Antistatic Coating Composition").

In addition, Korean patent technology (Korean Patent Registration No. 10-0389050, "Photocurable Transparent Conductive Coating Agent Containing A Conductive Polymer Aqueous Solution"), invented a UV curable antistatic solution composition using an aqueous conductive polymer solution. The use of the conductive oxide conductive polymer used and UV curing to cope with the existing deposition method of high temperature of 300 degrees or higher, or thermosetting material by UV curing instead of silica sol which needs to be hardened to 100 degrees or more. When the adhesive force is increased than when applied to a plastic film having flexibility and the like corresponds to the invention having the property that the deformation does not occur when the substrate is bent or the like.

However, the injection-molded product is coated to add anti-static performance after the product is already shaped and injected. It should be less scratched by friction during use, and should have resistance to alcohol used during the process and the surface lubricity. The property needs to be separated from one another. However, the 10-0389050 patent relates to an invention based on the use of conductive polymers instead of conductive oxides while adding flexibility to coat polymer films. It is also very important to add a lubricant to the coating composition of the injection molded article to increase the resistance to friction. That is, even if hard coating is applied, it is easily scratched if the surface is not provided with lubrication property. Also, even when the injections are separated from each other for use, the composition with a certain amount of lubricant is used to improve workability. It should be characterized.

In addition, there is a need when using a conductive polymer mixed with the ultraviolet curing composition. First, since UV curing may proceed additional reactions for a minimum of 24 hours up to a week, it is necessary to suppress the progress of the curing process to maintain the resistance realized by the initial conductive polymer. To this end, additives such as reaction inhibitors that can suppress further curing reaction should be mixed. In addition, if the tray is used under a long-term heat condition, a thermal oxidation reaction may proceed. In order to suppress this, an additive which can prevent oxidation must also be mixed in the composition. In addition, to increase the degree of curing during the initial reaction as much as possible to find a composition that does not proceed further, and to maintain the physical properties and lower the concentration of oxygen in the curing zone of the curing device, that is, by filling the nitrogen gas or inert gas to improve the reaction yield It is very important to increase it at an early stage. Therefore, the application of the composition of the present invention to the coating of the injection molding causes the above problems, the coating of the injection molding requires a composition or coating method that does not change the resistance as the reaction proceeds when mixed with the conductive polymer when used. .

Collectively, the techniques mentioned in these patents only mention that it is common, that is, an antistatic layer can be formed using a conductive polymer. That is, the German Bayer patent uses only a thermosetting binder, so even if it is coated on the surface of the polymer product, it is not possible to obtain a solid coating property, and the antistatic layer formed by these techniques is a phenomenon that the solution is separated and agglomerated with each other when stored for a long time. This may occur, or the adhesiveness with the base polymer is weak, so that it can easily come off from the tape test, can be easily peeled off or erased during handling, and if it is erased with an alcoholic solvent, it will not be easily erased or hard film properties can be obtained. . In addition, the Korean Patent No. 381392 patent said that an antistatic layer can be formed by using a conductive polymer in an injection molded product, but this is related to a general antistatic liquid composition, and the coating film properties that can solve the problems described above on the surface of an injection molded product The technology for forming a good antistatic layer is a situation that can not be applied.

Therefore, the invention of a novel UV curable antistatic liquid composition and antistatic layer treatment technology using the same for forming a antistatic layer having a strong coating film properties on the surface of various injection molded products including a large back light unit transportation container and not being wiped with alcohol solvents, and charging prepared therefrom The invention of anti-injection molded articles is needed.

In the present invention, a method for forming an antistatic layer having a strong coating film properties on the surface of various injection molded articles such as a large backlit unit transport container and not being wiped with alcohol solvents, a new ultraviolet curable antistatic composition applicable to an injection molded product, and a product prepared therefrom An antistatic injection molded article is provided.

The present invention also provides a method for imparting antistatic properties to an injection molding surface using an ultraviolet curable antistatic composition, a continuous cleaning and coating apparatus for the production of an antistatic injection molded article having a solid coating film property without being wiped with alcohol solvents, An object is to provide an antistatic injection molded product.

In order to achieve the above object, the present invention provides an ultraviolet curable antistatic composition which can give solid coating film properties when first formed on a surface, a coating method which can impart antistatic property to an injection molded product surface using the antistatic composition, and Provide the device.

First, the ultraviolet curable antistatic composition is 1-20 parts by weight of a conductive polymer, 1-30 parts by weight of an ultraviolet curable oligomer, 1-20 parts by weight of an ultraviolet curable monomer, 0.01-5 parts by weight of a photoinitiator, 0.01-5 parts by weight of a lubricating agent, It is prepared by mixing 0.01-2 parts by weight of UV stabilizer, 0.01-1 part by weight of reaction inhibitor, 0.01-1 part by weight of antioxidant and 16-96.95 parts by weight of solvent. It can optionally be added in the content.

The conductive polymer may be a modified conductive polymer such as polypyrrole, polyaniline, polythiophene, or poly (3,4-ethylenedioxythiophene) in the composition. When using the antistatic solution for coating the surface of the injection molding, the conductive polymers have different colors (for example, dark brown for polypyrrole, dark green for polyaniline, and pale light blue for polystyrenedioxythiophene). It is most effective to use poly (3,4-ethylenedioxythiophene). Particularly, poly (3,4-ethylenedioxythiophene) may be advantageous in terms of preventing environmental pollution because it can be made into a water dispersion state.

UV-curable binder resins include monomers and oligomers. Monomers are resins that have a small molecular weight and have double bonds, which easily open due to ultraviolet light and cause curing reactions to be polymers having high molecular weight. The oligomer is a relatively high molecular weight binder resin, mainly bi- or higher-functional acrylic resin or methacryl-based resin, that is, acrylate / methacryl containing a functional group of the urethane, epoxy, ester, acrylic, polybutadiene, silicone, melamine and dendrimer type When ultraviolet rays are irradiated as a rate, it is a binder resin in which a double bond is opened and becomes a polymer like a monomer. In addition, the use of oligomers having 6 or more functional groups, especially 12-15 functional groups, which have been recently developed and used among these bifunctional or higher oligomers, can exhibit the characteristics of a coating having a high curing speed and hard properties. In addition, the acrylate / methacrylate monomer can be used by curing with only one, but the use is mixed with a polyfunctional oligomer giving a physical property because the brittleness is too strong, it is preferable to improve the physical properties and increase the curing speed.

Representative photoinitiators used for UV curing include benzyl dimethyl ketal, hydroxy cyclohexyl phenyl ketone, hydroxydimethyl acetophenone, hydroxy diphenyl ethanone, 2,4,6-trimethylbezoyldiphenylphosphine, benzoin iso Propyl ether and benzophenone, 2-chloro thioxanone, isopyrophyll thioxanone and the like.

The crosslinking aid is used together with the photoinitiator to help the UV curing reaction during the UV curing reaction, and when used in an appropriate amount, it increases the degree of curing due to the UV curing reaction.

Lubricants are fluorine, phosphorus, or silicone-based surfactants that help disperse the components in the solvent and improve the wettability of the coating. These lubricants include fluorine-organic modified polysiloxanes, low molecular weight and high molecular weight polyacrylates, silicone polyacrylates, Polyethylen modified polysiloxane, fluorine modified polysiloxane, etc. can be used.

 The UV stabilizer is a component used for suppressing the conjugated double bond when the conductive polymer is exposed to ultraviolet rays, which may lower the conductivity. Therefore, 2,4 dihydroxybenzophenone and 2-hydroxy4-n-octoxybenzo Various types of ultraviolet stabilizers such as phenone and ethyl-2-cyano-3-3-diphenyl acrylate may be used.

Reaction inhibitors capable of inhibiting the further progress of the UV curing reaction may include compounds containing various kinds of siols. Typically, methyl mercaptan, ethyl mercaptan, normal propyl mercaptan, isopropyl mercaptan, and normal One or more types substituted with various functional groups such as butyl mercaptan, isobutyl mercaptan, sec butyl mercaptan, tertiary butyl mercaptan, normal amyl mercaptan, iso amyl mercaptan, normal hexyl mercaptan and dodecyl mercaptan Or it can mix and use. The reaction inhibitor is used to prevent the deterioration of the antistatic performance which is intended to be implemented by further reactions over time because of having a double bond rather than using the ultraviolet curing composition alone. In other words, the initiator remaining in the reaction not only decomposes the conductive polymer having a double bond while exposed to the general atmosphere, but also causes the resistance to change by adding an instability of the doped state between the conductive polymer and the dopant. Because of this, it is also possible to use a method that allows sufficient curing by increasing the degree of curing by injecting nitrogen or an inert gas into the curing apparatus without oxygen during the initial reaction, and it is very important to suppress the curing reaction to be further progressed.

Antioxidant for Preventing Thermal Oxidation Antioxidant for inhibiting Thermal Oxidation Deterioration is pentaerythryl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) -propinate ], Octadecyl 3- (3,5-di-tert-butyl-4-hydroxy phenyl) -propinate, triethylene glycol-bis-3 (3-tertary-butyl-4-hydroxy- 5-methylphenyl) propinate, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxy benzyl S-triazine-2,4,6- (1H3H5H) trione, thiethylene Hindered phenols such as bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propane] and tris- (2,4-di-tert-butyl-phenyl) phosphate; It is not limited to the said kind.

High boiling point glycols and glycerol can be used for viscosity control and dispersion improvement. Ethylene glycol, diethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol diethyl ether, di One or more of ethylene glycol diethyl ether, glycerol and glycerol diglycidyl ether can be used.

Additives such as lubricants are particularly preferred for nonionic and ionic surfactants and silicone or fluorine-based surfactant compounds in order to supplement wettability and spreadability during coating, and manufacturers of such products are DuPont, Dow Corning, Shin-Etsu, Wit Nose, 3M, etc. Lubricants and antifoaming agents manufactured and sold by these companies can be used when the total solution and the usability are available, and the product is not limited to the above company, depending on the use and the properties to be implemented. Optional use is possible.

Solvents that can be used in the composition include alcohols having 1 to 4 carbon atoms such as methanol, ethanol, isopropanol, propanol, butanol, and isobutanol among alcohols, and N-methyl-2-pi, which is an amide solvent. Lollidon, 2-pyrrolidone, N-vinyl-2-pyrrolidone, N-methylformamide, N, N-dimethylformamide can be used, and acetone, ethyl acetate, butyl acetate, toluene, chloroform Ether solvents such as methylene chloride and polyhydric alcohols may be selected from ethylene glycol, glycerol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether, or two or more solvents may be used in combination. When the two types are mixed, they can be mixed and used in a ratio of 5: 95-95: 5.

After coating the conductive polymer coating solution using the thermosetting method in addition to the above-mentioned ultraviolet curing composition, and coating and curing the ultraviolet curing composition alone thereon, the resistance to solvents such as alcohol is increased and is not easily peeled off by friction. Coated products can be made. As mentioned above, the general conductive polymer composition may be easily wiped off by a solvent or peeled off by friction, which is a good way to solve the problem. In addition, the method of forming the protective layer can be used using not only an ultraviolet curable composition but also a composition which can be cured by heat.

This principle reduces the physical properties of the thermosetting polymer binder and the UV curing agent itself, which are physical properties, when the conductive polymer is mixed for the antistatic performance. If the coating based on the conductive polymer is applied, the UV curing agent or the durability is If a strong thermosetting agent is coated, its own physical properties can be implemented, thereby obtaining a durable coating layer. However, in terms of process, there are disadvantages of applying two coats.

Regarding the method for coating the protective film, first, the composition used in the first layer may be a conductive polymer coating composition used in the Republic of Korea Patent Registration No. 381392, a known patent. In addition, the composition to be coated with a protective film thereon can be used both the UV-curable coating and the organic solvent type or water-soluble coating generally used in the present invention.

A method of forming an antistatic layer on the surface of an injection molded article according to the present invention will be described below. In the method of forming a permanent antistatic layer containing the conductive polymer as an active ingredient on the surface of the injection molding, a pretreatment step of washing the contaminants of the injection molding so that the antistatic layer is well formed on the surface of the injection molding, and forming an antistatic layer on the injection molding. A coating step, a drying step of drying the antistatic layer, and an ultraviolet curing step of curing the antistatic layer using ultraviolet rays.

In order to form the antistatic layer on the surface of the injection molded article using the antistatic liquid, a coating method such as an impregnation method or a spray coating method may be used. Among these methods, the antistatic layer forming method by impregnation method is to immerse the injection molded product in the bath containing the antistatic liquid, so that the antistatic liquid is sufficiently wetted on the surface of the injection molded product, and then remove the evaporated solvent to pass through the UV curing machine. Simply An antistatic layer having rigid coating film properties can be obtained. In addition, the coating by using the spray method has the advantage that can be effectively sprayed by coating the desired amount of the solution to the desired area.

Injection molding antistatic treatment by impregnation method or spray coating should first go through a cleaning process to wipe off contaminants such as release material sprayed on the mold surface to help release the injection molding product during injection molding. This cleaning process is to wash the injection molded product using ultrasonic wave while passing through the bath containing the cleaning agent. Typical cleaning agents include water, hexane, methyl alcohol, ethyl alcohol and isopropyl alcohol. Mixing with lower alcohols such as to bring the detergent content to 0.01-5 mole concentration can wash away contaminants such as release agents on the surface of the injection molded article. In addition, alcohol or hexane can be used alone because it can play a cleaning role alone without mixing the cleaning agent. In this case, the ultrasonic wave used may be an ultrasonic wave having a frequency of 1-100 kilohertz and an energy ranging from 10 watts to 1 kilowatt. Ultrasonic cleaning time varies depending on the energy of the ultrasonic wave, but can be cleaned in a time of 1-200 minutes.

After ultrasonic cleaning, the surface of the polymer injection molded product may need to be treated separately in order to prevent the antistatic liquid from getting wet on the surface of the polymer injection molded product so that the antistatic layer formed on the surface maintains good adhesion with the base injection product. have.

This surface treatment process mainly produces a basic aqueous solution mixed with ultrapure water so that basic components such as potassium hydroxide and sodium hydroxide have a concentration of 0.01-5 moles, and soaked in this solution for about 1-200 minutes, and then taken out of about 0.1-5 moles of acid. Neutralization in an aqueous solution results in functional groups that can improve the wettability and adhesion with the antistatic solution on the surface of the injection molded product. In addition, a process of removing dust through an ion generator may be introduced.

When the injection molded products cleaned and surface-treated by the above method are coated by impregnation, put them in a bath containing an antistatic liquid so that the antistatic liquid is sufficiently wetted on the surface of the injection molded product, and then the excess solvent flows out. After passing through the dryer, all residual solvents are removed, and the antistatic layer on the surface has a solid coating film during the ultraviolet irradiation chamber in which the ultraviolet lamp is installed. In addition, in the case of coating by spray method, after spraying the coating solution on the desired part, it is naturally dried or hot-dried and irradiated with ultraviolet rays.

If the coating is applied by impregnation, if the tray can be drained from the container containing the antistatic liquid, it should be provided with a passageway where the extra antistatic liquid flows down and collects in one place. Therefore, a solution flow fan made of a metal plate such as stainless steel having an inclination of about 1 to 45 degrees according to the viscosity of the antistatic liquid should be attached just under the path of the ejected product taken out of the antistatic liquid container. The extra antistatic solution collected through this passage can be collected at once and filtered to remove foreign substances, measure the concentration, add extra solvent, mix and use again.

The most preferred method of spray coating is to design an automated line to increase yield. Automated method of spray coating may automate the method of coating the coating section, in particular the composition on the product in the present invention. In other words, by spraying the spray gun as much as necessary in the horizontal and vertical direction using the rectangular coordinates, the spray amount may be adjusted and applied. In addition, a spray gun can be attached to the robot by moving it at various angles.

As the dryer, a hot air dryer may be mainly used. The hot air of the hot air dryer is sufficient to supply a hot air of about 5-200 rubes, the length of the dryer varies depending on the drying speed, preferably 1-20 meters. The length of the dryer should be up to about 20 meters long because the UV-curable antistatic liquid may cause incomplete UV curing or poor appearance of the surface layer if residual solvent is not completely removed.

After drying, the injection molded product undergoes an ultraviolet curing chamber in which an ultraviolet lamp is installed, and the antistatic liquid layer on the surface of the injected product is changed into a rigid form by ultraviolet rays. In this case, in general, since the shape of the injection molded product is often rectangular, ultraviolet rays should be irradiated from 3-6 directions to cure the entire rectangular injection molded product at once. In the case of three possible cases, when one of the top and two sides are operated, the front and the back may be processed while advancing. Preferably, the top, the front and the rear, and the left and right, respectively, five are required. . In the case of injection molded articles, the antistatic treatment of the upper part is particularly important, in which case it is advantageous to install two or more ultraviolet lamps on the upper side for perfect curing of the upper part. In addition, when the lower surface is hardened by being connected without flipping, the same structure of the back may be installed below.

The angle at which the UV lamp is installed is closely related to the UV irradiation angle, especially the UV lamps in front and behind from the direction of travel, depending on the height of the UV lamp installation, but the angle of the UV lamp is 10-45 degrees from the height of 10-30 centimeters. Irradiation is most effective. The same ultraviolet radiation angle applies to the sides.

Although the energy of the ultraviolet rays irradiated onto the surface of the injection molded article varies depending on the type of the polymer forming the target injection molded product, in the case of the present invention, it is cured by the energy of ultraviolet rays of 100 milli Joules-2,000 milli Joules. If the UV energy is less than 100 millimeters of Joules, UV curing is not enough to obtain a solid coating properties, and if it is higher than 2000 millimeters of Joules, the energy is too high and the surface is locally deformed.

In addition, as mentioned earlier, the UV curing machine is dried in the front of the UV curing machine and directly connected to the UV curing zone. When the nitrogen or inert gas is injected into the inside, the resistance change can be prevented over time. . That is to increase the yield of the initial reaction to proceed as hard as possible after the reaction can not proceed. For this purpose, the general air injection system used to cool the heat generated by ultraviolet rays can be changed to the nitrogen injection type. In addition to this method, the filter and the reflux device can be designed separately to inject and exhaust the UV rays, which are excellent in curing. In addition to obtaining a cured coating film, it is possible to prevent changes in the antistatic performance over time.

The thickness of the antistatic layer formed on the surface of the injection molded article is preferably adjusted to the solid content and viscosity of the antistatic solution so that the thickness of about 0.05-10 microns. The thicker the film thickness, the higher the surface hardness, which is advantageous for maintaining the film properties. Therefore, if the film thickness is thinner than 0.05 micron, the film may be damaged even by a weak impact.If the film thickness is thicker than 10 micron, the film thickness is too thick, so that the film may be peeled off during curing. It is rather disadvantageous because it is no longer big.

The preferred solids content to obtain the antistatic layer thickness is 0.1-40% and the viscosity is adjustable at 1-1,000 cps.

Designing the device so that all the processes such as the above-described pretreatment process, coating process, drying process, and UV curing process can be connected in-line in a continuous process is advantageous in terms of economically advantageous work.

In order to install the equipment on an inline, all the processes from washing to curing may be connected by one conveyor belt, or each process may be connected by a separate belt. In particular, the final UV curing process should allow the UV light from the bottom of the injection molded product to reach the lower surface of the product. First of all, the UV curing lamp is installed on the upper part only. Hardening may be used and a method of inverting it to harden the bottom plate again. To this end, there are two UV curing processes, in the middle of which are connected by a belt of about 2 meters, and when the top plate is hardened in the first step, it can be turned upside down so that the bottom plate can be hardened again while moving on the belt. have. This method is cumbersome, although it is cumbersome to overturn the injection molding after the first stage hardening, it is effective because perfect hardening can be achieved. In addition, by installing an ultraviolet curing lamp on the upper part and installing a lamp to irradiate the UV light on the lower part of the conveyor belt 1-5 meters behind the conveyor belt, it can be cured without inverting the injection molding. There is.

In addition, the speed of the UV curing machine can be adjusted at 100 ~ 1500 rpm depending on the thickness of the coating. In general, since the coating liquid is applied for a long time by impregnation or spraying, two or more coating zones are formed just before the inlet of the dryer. After drying in the UV cured has the advantage that can increase the mass productivity.

Hereinafter, the present invention will be described in detail with reference to examples, but the following examples are merely illustrative for describing the present invention and do not limit the scope of the present invention.

Comparative Example 1

10 grams of poly (3,4-ethylenedioxythiophene), 15 grams of urethane binder, 1 gram of N-methyl-2-pyrrolidinone, 1 gram of ethylene glycol, 0.1 gram of silicone surfactant, water: isopropyl alcohol (15: 85) A thermosetting antistatic solution was prepared by mixing with 72.9 grams of a mixed solvent, impregnated with a polyphenylene oxide specimen (2X10 centimeter rectangle), placed in a square tube, and then coated with an antistatic solution on the surface of the injection molded article. After drying at a temperature of 5 minutes to form a surface antistatic layer having a thickness of 1.0 microns.

The surface resistance of the antistatic layer on the surface formed by the above technique was uniformly 106 ohms / area and it was observed that the antistatic layer was peeled off when the antistatic layer was rubbed with the isopropyl alcohol on the Kimwipe paper and then rubbed with the antistatic layer. The pencil hardness of the antistatic layer was observed at 1H, and there was no improvement of the pencil hardness even after the surface antistatic layer was formed.

<Example 1>

5 grams of poly (3,4-ethylenedioxythiophene), 5 grams of 6-functional urethane acrylate oligomer, 5 grams of 12-functional epoxy acrylate oligomer, 5 grams of bifunctional monomer acrylate, 0.1 gram of hydroxy dimethylacetophenone as an initiator UV curable antistatic solution was prepared by mixing 0.01 grams of polyethylenated polysiloxane additive, 40 grams of isopropyl alcohol, and 39.89 grams of ethylene glycol monomer methyl ether, and placed in a square tube and injection molded polyphenylene oxide specimen (2 × 10 cm rectangular). After impregnating and applying the antistatic solution to the surface of the injection-molded article, dried for 5 minutes at a temperature of 100 degrees Celsius, and dried to apply a 400mJ ultraviolet light to harden to form a surface antistatic layer having a thickness of 1.0 micron.

The surface resistance of the antistatic layer on the surface formed by the above technique was uniformly 10E6 ohms / area and the antistatic layer was not peeled off even after rubbing the antistatic layer with isopropyl alcohol on the Kimwipe paper. In addition, the pencil hardness of the antistatic layer was observed to be 2H, and even after the surface antistatic layer was formed, it was observed that the pencil hardness was improved by an ultraviolet curing agent and a curing method having excellent pencil hardness durability.

Comparative Example 2

After filling the solution prepared in Example 1 in a square barrel of 1.5 meters each, it was not subjected to a separate washing process after injection molding a large LCD backlight unit carrying container using a polyphenylene oxide resin. In order to assist with separation from the mold during injection, the mold was sprayed on the surface of the mold and then injection molded. Put the injection tray itself into this container, and then take out the antistatic liquid, remove it, remove the solvent for 5 minutes at a temperature of 100 degrees Celsius, and 6 UV lamps are installed in each of the upper, lower, left, and right sides of the curing machine. The UV curable was passed through UV curing with energy of 300 milli Joules to form a surface antistatic layer having a thickness of 1.0 micron.

The surface resistance of the antistatic layer on the surface of the tray for transporting the backlight unit formed by the above technique was 10E6 ohm / area, and when the isopropyl alcohol was applied to the Kimwipe paper and then rubbed on the antistatic layer, the antistatic layer on the surface did not peel off at all. Pencil hardness of the surface layer was measured by 2H to improve the firmness of the surface coating film.

However, due to the poor wettability, the antistatic solution was not easily spread and agglomeration was found, and the antistatic layer on the surface was peeled off by the tape test according to ASTM D3359 method. It was found that it acts as a factor to lower the wettability and adhesion.

<Example 2>

In Example 2, the injection molded large backlight unit was first put into a bath containing isopropyl alcohol, ultrasonically cleaned for 2 minutes using an ultrasonic cleaning tank having a frequency of 20 kHz and 350 watts of energy, and then dried again. A tray was used and the other coating and curing methods were the same as in Comparative Example 1.

The surface resistance of the surface antistatic layer formed by the above technique was 10E6 ohms / area, and when the antistatic layer was rubbed with the isopropyl alcohol on the Kimwipe paper, the antistatic layer on the surface was not peeled off at all. Was measured by 2H to improve the firmness of the surface coating film. In particular, the coating state of the antistatic layer on the surface was very uniform, it was confirmed that the washing treatment of the injection molded article of Example 2 greatly improved the wettability and adhesion of the antistatic solution.

<Example 3>

In Example 3, an injection molded large backlight unit injection was placed in an aqueous solution tank made of 1.0 mol of sodium hydroxide and ultrasonically cleaned in an ultrasonic cleaning tank having a frequency of 20 kHz and 350 watts for 3 minutes, followed by 0.1 mol of dilute nitric acid solution. Dipped in neutralized. The coating and curing methods were the same as those of Comparative Example 1 except that the resultant was washed with tap water again and dried trays were used.

The surface resistance of the surface antistatic layer formed by the above technique was 10E6 ohms / area, and when the antistatic layer was rubbed with the isopropyl alcohol on the Kimwipe paper, the antistatic layer on the surface was not peeled off at all. Was measured by 2H to improve the firmness of the surface coating film. In particular, the coating state of the antistatic layer on the surface was very uniform, it was confirmed that the washing treatment of the injection molded article of Example 3 greatly improved the wettability and adhesion of the antistatic liquid.

<Example 4>

Example 4 relates to spraying a coating method, 5 grams of poly (3,4-ethylenedioxythiophene), 5 grams of 6-functional urethane acrylate oligomer, 5 grams of 12-functional epoxy acrylate oligomer, bifunctional monomer acrylic Ultraviolet curable antistatic solution was prepared by mixing a rate of 5 grams, 0.1 gram of hydroxy dimethylacetophenone as an initiator, 0.01 gram of polyethylenated polysiloxane additive, and 40 grams of isopropyl alcohol and 39.89 grams of ethylene glycol monomer methyl ether. The unit injection was first put into a bath containing isopropyl alcohol, ultrasonically cleaned for 2 minutes using an ultrasonic cleaning tank having a frequency of 20 kilohertz and an energy of 350 watts, and then taken out again, and a dry tray was used.

10 trays of each of the trays were installed in horizontal and vertical rectangular coordinates, and coating was performed in a moving spray coating zone. After removing the solvent for 5 minutes at a temperature of 80 degrees Celsius, it passes through an ultraviolet curing machine equipped with six ultraviolet lamps, one for each of the top, bottom, left, and right sides of the inside of the curing machine, and is UV cured with 300 milli Joules of energy to have a thickness of 0.5 micron. A surface antistatic layer was formed.

The surface resistance of the antistatic layer on the surface of the tray for transporting the backlight unit formed by the above technique was 10E6 ohm / area, and when the isopropyl alcohol was applied to the Kimwipe paper and then rubbed on the antistatic layer, the antistatic layer on the surface did not peel off at all. The pencil hardness of the surface layer was measured at 2H, and it was observed that the surface coating film was solid and there was no trace of flowing solution, and the appearance was very clean.

Example 5

Example 4 relates to spraying a coating method, 5 grams of poly (3,4-ethylenedioxythiophene), 5 grams of 6-functional urethane acrylate oligomer, 5 grams of 12-functional epoxy acrylate oligomer, bifunctional monomer acrylic Ultraviolet curable antistatic solution was prepared by mixing a rate of 5 grams, 0.1 gram of hydroxy dimethylacetophenone as an initiator, 0.01 gram of polyethylenated polysiloxane additive, and 40 grams of isopropyl alcohol and 39.89 grams of ethylene glycol monomer methyl ether. The unit injection product was put in an aqueous solution tank made of 1.0 molar sodium hydroxide, and was ultrasonically cleaned in an ultrasonic cleaning tank having a frequency of 20 kHz and 350 watts for 3 minutes, and then immersed in 0.1 mol of diluted nitric acid solution and neutralized. It was washed again with tap water and then used a dry tray.

The trays were horizontally and vertically coordinated so that each of 10 spray guns were installed, and the coating was performed in a moving spray coating zone. After removing the solvent for 5 minutes at a temperature of 80 degrees Celsius, it passes through an ultraviolet curing machine equipped with six ultraviolet lamps, one for each of the top, bottom, left, and right sides of the inside of the curing machine, and is UV cured with 300 milli Joules of energy to have a thickness of 0.5 micron. A surface antistatic layer was formed.

The surface resistance of the antistatic layer on the surface of the tray for transporting the backlight unit formed by the above technique was 10E6 ohm / area, and when the isopropyl alcohol was applied to the Kimwipe paper and then rubbed on the antistatic layer, the antistatic layer on the surface did not peel off at all. The pencil hardness of the surface layer was measured at 2H, and it was observed that the surface coating film was solid and there was no trace of flowing solution, and the appearance was very clean.

Comparative Example 3

Comparative Example 3 relates to an experiment of observing a resistance change over time, and is a result of observing resistance over time for the surface resistance of the large backlight tray manufactured in Example 2. Surface resistance was measured using ST-3 of SRM110 Japan SIMCO of Pinion, USA for comparison.

The tray produced in Example 2 was increased by 1 order from 10E6 ohms / area to 10E7 ohms / area after 24 hours, and increased to 10E9 after 3 days.

<Example 6>

Example 6 is to confirm the action of the reaction inhibitor and the thermal antioxidant, 5 grams of poly (3,4-ethylenedioxythiophene), 5 grams of 6-functional urethane acrylate oligomer, 5 grams of 12-functional epoxy acrylate oligomer, 5 grams of bifunctional monomer acrylate, 0.1 gram of hydroxy dimethylacetophenone as an initiator, 0.01 gram of polyethylenated polysiloxane additive, 0.01 gram of dodecyl mercaptan and tris- (2,4-di-tert-butyl phenyl) phosphate An ultraviolet curable antistatic solution was prepared by mixing 0.01 gram and 40 grams of isopropyl alcohol and 39.89 grams of ethylene glycol monomer methyl ether, and the other coating and curing methods were used in the method of Example 2.

The surface resistance of the surface antistatic layer formed by the above technique was 10E6 ohms / area, and when the antistatic layer was rubbed with the isopropyl alcohol on the Kimwipe paper, the antistatic layer on the surface was not peeled off at all. Was measured by 2H so that no change in surface by the additive was observed.

The tray was observed in the surface resistance change over time in the same manner as in Comparative Example 3, the tray prepared in Example 6 does not change the resistance after 24 hours, 48 hours, 72 hours and one week Was observed to confirm the effect of the reaction inhibitor.

<Example 7>

Example 7 relates to a method for forming a protective layer, wherein 10 grams of poly (3,4-ethylenedioxythiophene) used in Comparative Example 1, 15 grams of a urethane binder, and 1 gram of N-methyl-2-pyrrolidinone , 1 gram of ethylene glycol, 0.1 gram of silicone surfactant, water: isopropyl alcohol (15:85) mixed with 72.9 grams of a solvent to prepare a thermosetting antistatic solution and spray-coated on the injection of a large backlight unit 1 at 80 degrees Dried over minutes. On top of that, 10 grams of 6-functional urethane acrylate oligomer, 10 grams of 12-functional epoxy acrylate oligomer, 5 grams of bifunctional monomer acrylate, 0.5 grams of hydroxy dimethylacetophenone as an initiator, and 0.03 grams of polyethylenated polysiloxane additive were ethyl. The solution prepared by diluting the solution diluted with 74.47 grams of acetate was dried for 1 minute at a temperature of 80 degrees, and cured by applying 400 mJ of ultraviolet rays to form a surface antistatic layer having a thickness of 0.5 microns.

The surface resistance of the tray manufactured as described above was 10E7 ohms / area, and the antistatic layer was not peeled off even after rubbing the antistatic layer with isopropyl alcohol on the Kimwipe paper.

<Example 8>

Example 8 relates to a degree of curing and prevention of surface resistance change when the ultraviolet curing zone is filled with nitrogen gas. The nitrogen is connected to an air inlet for cooling the ultraviolet curing zone, and the nitrogen is introduced to the internal air. Except for converting, the same method as in Example 2 was used.

As described above, the trays prepared in Example 7 were observed to change in surface resistance over time in the same manner as in Comparative Example 3. The trays prepared in Example 7 were 24 hours, 48 hours, 72 hours, and one week, respectively. It has been observed that the resistance does not change over time, so that if the initial reaction is made as efficient as possible, the additional reaction proceeds to prevent the resistance from changing.

Example 9

Example 9 relates to a washing, coating, drying and curing apparatus, first with an ultrasonic cleaner, followed by a 5 meter tunnel dryer with air flow of up to 50 rubes, which can be heated up to 150 degrees connected by a conveyor belt. It was. Then, the anti-static liquid container of 1.5 meters in size was placed, followed by a 10-meter, 150-degree, 100-lube hot air dryer connected by a conveyor belt. The front 7 meters of this hot air dryer is designed to suck in the evaporating solvent rather than blowing in the hot air to remove the naturally evaporating solvent from the surface of the ejected product after it has been impregnated with the antistatic liquid and then the remaining 8 meters of area. Forced evaporation by hot air at. At the end of this hot air dryer, six UV lamps (two top, one left, one front and rear, total 6) were installed to adjust the height to 10-30 centimeters and 10-30 centimeters on the side. The air inlet for allowing nitrogen gas to be injected. Then there was a 2 meter long conveyor belt and again the same hardening chamber as the previous hardening chamber was set up to reverse the injection through the front hardening chamber to cure the bottom plate, followed by a 2 meter long empty belt. To allow the final product to be removed from the conveyor belt.

A large backlight unit (960X1020 millimeter size) injection molded using a polycarbonate-acrylonitrile-butadiene-styrene (PC-ABS) mixture using a release agent after pouring the solution into each barrel using this device. An antistatic layer was formed on the surface.

Wetness and adhesion of the antistatic layer formed by the device was very good, and the antistatic layer formed on the surface was not peeled off even if wiped with a Kimwipe paper soaked with isopropyl alcohol, and the pencil hardness of the surface was 1H, resulting in an untreated PC-ABS mixture. It was observed that the pencil hardness of the coating layer was improved to B, which is the pencil hardness of the injection molded article.

<Example 10>

Example 10 relates to the same continuous pretreatment, coating and curing process apparatus as in Example 9 but to a method in which the coating part consists of a spray zone, first with an ultrasonic cleaner and then with a maximum of 150 degrees connected by a conveyor belt. A 5 meter tunnel dryer was installed with a maximum air flow rate of 50 rubes, which could be heated up to. In addition, an automatic spray device with 10 spray guns was installed in Cartesian coordinates, and after this zone, drying by hot air was carried out in an area of 8 meters. At the end of this hot air dryer, six UV lamps (two top, one left, one front and rear, total 6) were installed to adjust the height to 10-30 centimeters and 10-30 centimeters on the side. The air inlet for allowing nitrogen gas to be injected. Afterwards, an automatic spraying device with 10 spray guns was installed in Cartesian coordinates, and the backside was coated and the same curing chamber as the previous curing chamber was installed to cure the back side of the injection through the front curing chamber. A 2 meter long empty belt was then installed to allow the final product to be removed from the conveyor belt.

A large backlight unit (960X1020 millimeter size) injection molded using a polycarbonate-acrylonitrile-butadiene-styrene (PC-ABS) mixture using a release agent after pouring the solution into each barrel using this device. An antistatic layer was formed on the surface.

Wetness and adhesion of the antistatic layer formed by the device was very good, and the antistatic layer formed on the surface was not peeled off even if wiped with a Kimwipe paper soaked with isopropyl alcohol, and the pencil hardness of the surface was 1H, resulting in an untreated PC-ABS mixture. It was observed that the pencil hardness of the coating layer was improved to B, which is the pencil hardness of the injection molded article.

By using the method of forming a permanent antistatic layer on the injection molding according to the present invention and the permanent antistatic composition and the curing device, the product is easily removed without being removed in alcohol solvents such as isopropyl alcohol and has a solid coating film properties. It is possible to obtain an injection molded article that maintains permanent antistatic properties without any change in surface resistance.

Claims (17)

In the method of forming a permanent antistatic layer containing the conductive polymer as an active ingredient on the surface of the injection molded product, The above method A pretreatment step of washing the contaminants of the injection molding so that the antistatic layer is well formed on the surface of the injection molding; A coating process for forming a permanent antistatic layer containing a conductive polymer as an active ingredient on the entire surface of the injection molding; A drying step of drying the antistatic layer, and An ultraviolet curing process of curing the antistatic layer using ultraviolet rays, To include, wherein the antistatic layer is formed in a thickness of 0.05-10 microns and having a property that does not wipe the alcohol solvent, Method for forming a permanent antistatic layer, characterized in that the injection molding. The permanent antistatic layer according to claim 1, wherein in the pretreatment process, surface treatment, neutralization treatment, or surface treatment and neutralization treatment in addition to washing are further performed to enhance the wettability and adhesion of the antistatic liquid to the surface of the injection molded product. How to form on injection molding. The method of claim 1, wherein the coating method in the coating process is a method of forming a permanent antistatic layer to the injection molding, characterized in that using the impregnation method or spray method. The method of claim 1, wherein in the ultraviolet curing process, a plurality of ultraviolet lamps are selected from up, down, left, and right sides from the advancing direction of the injection product, and a total of 3-6 are installed in each one to induce UV curing at once. Method for forming a permanent antistatic layer on the injection molding, characterized in that using. The method of claim 4, characterized in that the height of the UV ram and the distance from the injection molded product can be adjusted within 10-30 centimeters so that the irradiation of ultraviolet light is possible by adjusting the height and distance of the lamp even in injection molded products having different sizes. A method of forming a permanent antistatic layer in an injection molding. The method according to claim 4, wherein the upper and lower ultraviolet lamps are installed at least 30 centimeters apart from each other in a planar position so as not to face each other. The method according to claim 4, wherein the ultraviolet lamps installed in front, back, left, and right directions from the direction of injection molding can adjust the angle of ultraviolet irradiation in the range of 5-45 degrees. 5. The method of claim 4, wherein nitrogen or an inert gas is introduced in the ultraviolet process. The permanent antistatic layer according to any one of claims 1 to 8, wherein at least two of the above processes are formed in a continuous process by connecting a pretreatment process, a coating process, a drying process, and a curing process with a conveyor belt. How to form on injection molding. 10. The method of claim 9 wherein the conveyor belt uses a belt made in the form of a bar to allow ultraviolet light to pass through from the bottom during the curing process. The method according to any one of claims 1 to 8, The coating process for forming an antistatic layer on the injection molding is carried out by a thermal curing method, and the ultraviolet curing process for curing the antistatic layer with ultraviolet light is carried out by coating and curing a single component of the ultraviolet curing composition. A method of forming a permanent antistatic layer on an injection molding. An antistatic composition for forming an antistatic layer containing a conductive polymer as an active ingredient on the surface of an injection molded product, The antistatic liquid is 1-20 parts by weight of a conductive polymer, 1-30 parts by weight of an ultraviolet curable oligomer, 1-20 parts by weight of an ultraviolet curable monomer, 0.01-5 parts by weight of a photoinitiator, 0.01-5 parts by weight of a lubricating agent, and an ultraviolet stabilizer. Antistatic coating composition for injection molding, characterized in that it is not wiped with alcohol solvents, including 0.01-2 parts by weight, reaction inhibitor 0.01-1 parts by weight, antioxidant 0.01-1 parts by weight and solvent 16-96.95 parts by weight. 13. The antistatic coating composition for injection molding according to claim 12, wherein the conductive polymer is polypyrrole, polyaniline, polythiophene, or poly-3,4-ethylenedioxythiophene, and a modified conductive polymer modified therefrom. 13. The acrylate / methacrylate oligomer according to claim 12, wherein the ultraviolet curable oligomer comprises functional groups of urethane, epoxy, ester, acryl, polybutadiene, silicone, melamine and dendrimer type and at least one functional group of acrylate / methacrylate. Antistatic coating composition for injection molding, characterized in that the monomers are used alone or in combination. 13. The reaction inhibitor according to claim 12, wherein the reaction inhibitor is methyl mercaptan, ethyl mercaptan, normal propyl mercaptan, isopropyl mercaptan, normal butyl mercaptan, isobutyl mercaptan, sec butyl mercaptan, tertiary butyl mercaptan, normal amyl An antistatic coating composition for injection molding, characterized in that it is used singly or in combination with a thiol compound such as mercaptan, iso amyl mercaptan, normal hexyl mercaptan, dodecyl mercaptan. The antistatic coating composition for injection molding according to any one of claims 12 to 15, wherein the composition is used in the coating process of the method of forming the permanent antistatic layer of claims 1 to 8. An injection molding provided with a permanent antistatic layer comprising a conductive polymer prepared by a method of forming the permanent antistatic layer of any one of claims 1 to 8 in the injection molding.