KR102056433B1 - A method of manufacturing a case for a portable terminal having an anti-static function and a case - Google Patents

Abstract

According to one aspect of the present invention, a method for manufacturing a portable terminal case having an antistatic function and forming a mobile terminal, comprises: a step (A) of milling a resin obtained by mixing any one or two or more among PVC, PC, PE, ABS, and acrylic resins to prepare raw material powder of the case; a step (B) of milling metal obtained by mixing any one or two or more among silver (Ag), copper (Cu), and aluminum (Al) to prepare particle-modified antistatic raw material powder; a step (C) of mixing 3.0 to 10 wt% of the antistatic raw material powder to 90 to 97 wt% of the prepared raw material powder of the case, and heating the mixture at 190 to 240°C; a step (D) of stirring the mixture melted by being heated at 300 to 500 RPM to disperse the antistatic raw material powder; and a step (E) of injecting or extruding the dispersed mixture into or through a forming mold of a preset shape to complete the portable terminal case. Accordingly, by mixing an antistatic agent with a synthetic resin, which is a main material of the case to earth static charges generated from a terminal to the air, an effect of protecting the terminal as well as a user can be provided.

Description

A method for manufacturing a case for a portable terminal having an anti-static function and a case}

The present invention relates to a method for manufacturing a case such as a rear body or a front body (liquid crystal) constituting a portable electronic terminal, and more particularly to a case for a portable terminal manufactured therein. The present invention relates to a method of manufacturing a case for a portable terminal having an antistatic function capable of protecting the user as well as the terminal as the static electricity generated in the terminal is grounded in the air, and a case for the portable terminal manufactured therewith.

Normally, static electricity is always generated in daily life, and when the user takes off the clothing of the synthetic fiber on a dry day such as winter, the discharge of static electricity can be seen by the eyes or by the ears. This static electricity can be thought of as an excess of charge that temporarily stays on the surface of an object. That is, a large amount of charge temporarily staying on the surface of the object is generated due to the excess or lack of electrons occurring on the surface of the object.

Static electricity can be divided into two main categories: frictional static electricity generated when two objects come into contact and then separated again, and induced static electricity generated when there is a conductive object around a charged object. In particular, induced static electricity of tens of thousands of volts is causing serious damage to electronic products.

When exposed to sudden static electricity in winter, no harm is done to the human body, but electronic equipment can be damaged by static electricity, which is not perceived by the human body. In recent years, most electronic components and electronic equipment include highly integrated circuits, and expensive electronic or electromagnetic products are highly unlikely to lose their function or lose some of their functions due to the effects of static electricity.

That is, if the electrostatic discharge has enough energy, serious damage can occur due to local overheating in the electronics. In general, more sophisticated electronic equipment is more sensitive to damage from static electricity.

Therefore, in order to prevent such a problem, Korean Patent Publication No. 10-0825418, Korean Patent Publication No. 10-0614868 and Korean Utility Model Publication No. 20-0353367 have been proposed.

The former is a mixture consisting of Group 3B elements on the Periodic Table of the Elements to form a metal-colored thin film layer, and the middle constitutes a shield member that electrically connects the case coated with EMI paint and the EMI paint coating layers on the front and back of the case. The latter is sprayed with silver powder on one side of the window to prevent static electricity to prevent damage to the human body as well as the device.

However, in order to exhibit a relatively good grounding performance, the surface area must contain 5 to 15% of the conductor component. By the way, the components of the conductor components are strongly bound to each other, the case in which the action is generated there is a problem that causes the defect due to the deformation or deterioration of the corresponding portion.

Republic of Korea Patent Publication No. 10-0825418 (Invention name: anti-static thin film of the case appearance and manufacturing method thereof) Republic of Korea Patent Publication No. 10-0614868 (name of the invention: a mobile communication terminal having a case for preventing electrostatic charge and leakage current blocking) Republic of Korea Utility Model Registration No. 20-0353367 (Name of Design: Structure of Nameplate of Anti-Static Mobile Phone Window)

The present invention was created in order to more actively solve the above problems, and the metal compound per ground surface area of the case by modifying the size and shape of the particles followed by powder treatment of the metal compound performing the grounding function in the atmosphere is 5 to It is an object of the present invention to provide a method for manufacturing a case for a portable terminal having excellent quality and a grounding function, and a case for the portable terminal manufactured therein by being distributed at 15% or more.

In order to achieve the above problem, the configuration of the manufacturing method of the case for a mobile terminal having the antistatic function proposed in the aspect of the present invention is as follows.

Method of manufacturing a case for a mobile terminal having the antistatic function above is a method of manufacturing a case constituting a mobile terminal: (A) PVC, PC, PE, ABS, acrylic, or any one or two of these resins are mixed Pulverizing to prepare a case raw powder; (B) pulverizing the conductive metal to prepare an antistatic raw material powder modified particles; (C) blending 90 to 97% by weight of the prepared case raw material powder with 3.0 to 10% by weight of antistatic raw material powder, and heating the blended mixture to 190 to 240 ° C; (D) stirring the molten mixture at 300 to 500 RPM to disperse the antistatic raw material powder; (E) injecting or extruding the dispersed mixture into a mold having a predetermined shape to complete a case for a mobile terminal; and characterized in that it comprises a.

In order to achieve the above object, the configuration of the manufacturing method of the case for a mobile terminal having the antistatic function proposed in another aspect of the present invention is as follows.

The method of manufacturing a case for a mobile terminal having the antistatic function is provided in the method of manufacturing a case for forming a mobile terminal: (A) preparing a case for a mobile terminal by injecting or extruding a synthetic resin into a mold having a predetermined shape; (B) pulverizing the conductive metal to prepare an antistatic raw material powder modified particles; (C) preparing an adhesive mixed with any one or two or more of isopropyl alcohol, UV ink, solvent ink; (D) blending the prepared antistatic raw material powder 98-99.2% by weight of the adhesive 0.8-2.0% by weight, and stirring the blended mixture to disperse the antistatic raw material powder; (E) applying a dispersion treatment to the prepared case to a thickness of 10 to 100㎛ to complete the case for the mobile terminal; characterized in that it comprises a.

At this time, the step (B) according to the present invention is to crush the metal with an air-jet dry mill to convert the size of the particles into ultra-fine particles of 0.3 to 4.0㎛ while deforming the shape of the particles from a uniform spherical to crushed oval or square It is characterized by.

In addition, in the above step (D) according to the present invention, the blended mixture is stirred and mixed at 300 to 500 RPM, and then the stirred mixture is added to a freezer to cool below freezing, and then the freeze-cured mixture is put into an ice-water grinder. It is characterized by.

In addition, the above step (E) according to the present invention is added to 1 ~ allyl-3-methylimidazolioum chloride having both cations and anions 1.0 ~ 4.0% by weight to 99 ~ 96% by weight of the mixture mixture, then 500 to 1000RPM It is characterized by stirring.

The case for a mobile terminal manufactured by the method for manufacturing a case for a mobile terminal having the above antistatic function contains 5 to 15% or more of antistatic raw material powder per unit surface area, and has a 0.72 to 1.9 kV charging potential and 10 ¹⁰ Ω / cm ^It is characterized by having a surface resistance of ² ~ 10 ¹² / cm ² .

In order to achieve the above object, the configuration of the manufacturing method of the case for a portable terminal having the antistatic function proposed in another aspect of the present invention is as follows.

Method of manufacturing a case for a mobile terminal having the antistatic function above, the method for manufacturing a case constituting a mobile terminal: (A) preparing an insulating resin master batch for the case; (B) preparing an antistatic conductive resin master batch; (C) blending from 90 to 97% by weight of the prepared case master batch at 3.0 to 10% by weight of the antistatic master batch and heating the blended mixture to 190 to 240 ° C; (D) stirring the molten mixture at 300 to 500 RPM to disperse the insulating resin and the conductive resin; (E) injecting or extruding the dispersed mixture into a mold having a predetermined shape to complete a case for a mobile terminal; and characterized in that it comprises a.

According to the present invention having the above-described configuration, while reducing the size of the grounding metal particles into ultra-fine particles, the shape of the particles is modified to crushed oval or square shape, and then freeze-hardened, and then changed into ice-water, resulting in high concentration and high dispersibility of the metal powder. Overall, it provides the effect that you can expect excellent stiffness and excellent antistatic performance.

1 is a flow chart showing a manufacturing method according to an embodiment of the present invention.
2 is a flow chart showing a manufacturing method according to another embodiment of the present invention.
3 is a flow chart showing a manufacturing method according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in a batch about the configuration of the present invention and its effects, effects.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms, and only the present embodiments are provided to make the disclosure of the present invention complete and common knowledge in the technical field to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. And like reference numerals refer to like elements throughout the specification.

One aspect of the present invention relates to a method for manufacturing a case such as a rear protective body or a front liquid crystal body constituting a portable electronic terminal, and relates to a case for a portable terminal manufactured through steps (A) to (E) as shown in FIG. 1. will be. The production method of the present invention is an internal additive type to have an antistatic effect by adding an antistatic agent therein during the extrusion or injection of the synthetic resin.

Step (A) prepares the raw material for the case constituting the portable electronic terminal. That is, the case raw material may be composed of any one of PVC, PC, PE, ABS, acrylic, or a resin mixed with two or more thereof. The prepared resin is pulverized with a grinder to form a fine powder of 100 to 500 mash.

Step (B) prepares an antistatic material that performs a grounding function in the atmosphere. That is, the antistatic material may be composed of any one of silver (Ag), copper (Cu), aluminum (Al), or a metal mixed with two or more of them, which are conductive materials. Of course, in addition to the metals mentioned, it may also consist of other conductive metals such as carbon or nickel. The prepared metal is ground in a grinder to form a particulate powder. The powdered metal powder is then introduced into an air-jet dry mill to modify the size and shape of the particles.

Here, the air-jet dry milling machine injects a strong air pressure to cause the particles of the metal powder to collide with each other. Such a dry mill converts the size of the metal powder particles into ultra-fine particles of 0.3 to 4.0 mu m, and transforms the shape of the particles from a uniform spherical shape to a crushed elliptical shape or a square shape. Therefore, the particles of the metal powder is converted into ultra-fine particles, and the dispersibility is improved, and the surface of the particles is coarse and widened to double the grounding function of the metal powder.

Step (C) produces a mixture that is the master batch for the case. That is, the prepared case raw material powder is blended in an amount of 3.0 to 10% by weight of the antistatic raw material powder, and the blended mixture is heated to 190 to 240 ° C. Here, the case raw material powder is preheated and melted, and then the antistatic raw material powder is preferably added.

Step (D) disperses the antistatic raw material powder in the molten case raw material. That is, the mixture melted by heating is stirred at 300 to 500 RPM and mixed uniformly. Then, the stirred mixture was introduced into the freezer at a fixed size of 5 cm 3, cooled to below zero, and then the freeze-cured mixture was put into an ice water and ground. Therefore, not only can be used in a quantitative manner in a subsequent step, but also the particles of the unmodified metal powder can be reformed again.

Step (E) completes the case for the mobile terminal with a mixture of the case material and the antistatic material. That is, the dispersion-treated mixture is injected or extruded into a mold having a predetermined shape to manufacture a case for a mobile terminal. Here, it is preferable to add imidazole (1-allyl-3-methylimidazolioum chloride) to the dispersed mixture.

Imidazole is a substance contained in the ionic liquid. The ionic liquid is a molten salt composed of inorganic anions of a smaller size than organic cations of a heterocyclic structure including nitrogen. The cations and anions are asymmetric in size and do not form crystals, so they exist in the liquid state.

In addition, imidazole has both a cationic portion and an anionic portion and is used as an amphoteric surfactant. Amphoteric surfactants are applicable in almost all pH ranges and make it possible to mix with all surfactants.

Applications include high foaming, wetting, foam stability, emulsifying, detergency and dispersion with lime soap. In addition, there is no need for preservatives because of its compatibility with electrolytes, excellent hydrolysis stability, quaternary ammonium bactericidal properties and bacterial growth inhibition.

That is, 1.0 to 4.0 wt% of imidazole is added to 99 to 96 wt% of the dispersed mixture, and then stirred at 500 to 1000 RPM, followed by injection or extrusion into a mold having a predetermined shape to manufacture a case for a mobile terminal. Here, for dispersibility of imidazole, it is preferable to add methyl ethyl ketone (MEK) as a solvent in a 1: 1 weight ratio to the mixture.

The case for a mobile terminal manufactured by this process contains 5 to 15% or more of antistatic raw material powder per unit surface area, and has a 0.72 to 1.9 kV charging potential and a 10 ¹⁰ Ω / cm ² to 10 ¹² / cm ² surface resistance. Therefore, due to the high concentration of metal powder, high dispersibility, and hydrophilicity by imidazole, the surface resistance can be minimized, and thus, excellent overall rigidity and excellent antistatic performance can be expected.

Another aspect of the present invention relates to a method for manufacturing a case such as a rear protective body or a front liquid crystal body constituting a portable electronic terminal, the case for a portable terminal manufactured through the steps (A) to (E) as shown in FIG. It is about. The manufacturing method of this invention is a surface coating type which shows an antistatic effect by spraying an antistatic agent on the target surface.

Step (A) melts the synthetic resin to prepare a case for a mobile terminal. That is, the resin mixed with any one of PVC, PC, PE, ABS, acrylic or two or more thereof is pulverized by a grinder to form a fine powder of 100 to 500 mesh. Then, the case powder raw material is melted, and then injected or extruded into a mold having a predetermined shape to produce a case.

Step (B) prepares an antistatic material that performs a grounding function in the atmosphere. That is, the antistatic material may be composed of any one of silver (Ag), copper (Cu), aluminum (Al), or a metal mixed with two or more of them, which are conductive materials. Of course, in addition to the metals mentioned, it may also consist of other conductive metals such as carbon or nickel. The prepared metal is ground in a grinder to form a particulate powder. The powdered metal powder is then introduced into an air-jet dry mill to modify the size and shape of the particles.

Here, the air-jet dry milling machine injects a strong air pressure to cause the particles of the metal powder to collide with each other. Such a dry mill converts the size of the metal powder particles into ultra-fine particles of 0.3 to 4.0 mu m, and transforms the shape of the particles from a uniform spherical shape to a crushed elliptical shape or a square shape. Therefore, the particles of the metal powder is converted into ultra-fine particles, and the dispersibility is improved, and the surface of the particles is coarse and widened to double the grounding function of the metal powder.

Step (C) prepares an adhesive for coating the antistatic raw material powder on the case. The adhesive may be composed of any one or two or more of isopropyl alcohol (Isopropyl alcohol), UV ink, solvent ink.

At this time, the primer is applied to the surface of the case produced through the step (A) in the preparation of the adhesive. That is, by applying a polymer material such as alkyltrialkoxysilane and acrylate to the surface, the adhesion is enhanced in a subsequent application step.

Step (D) produces a mixture to be a master solvent for case coating. That is, 0.8-2.0 wt% of the adhesive is blended with 98-99.2 wt% of the prepared antistatic raw material powder, and the blended mixture is stirred uniformly at 300-500 RPM. Then, the stirred mixture was introduced into the freezer at a fixed size of 5 cm 3, cooled to below zero, and then the freeze-cured mixture was put into an ice water and ground. Therefore, not only can be used in a quantitative manner in a subsequent step, but also the particles of the unmodified metal powder can be reformed again.

Step (E) sprays a mixture of the antistatic raw material and the adhesive onto the surface of the case. In other words, the dispersion is applied to the prepared case to a thickness of 10 to 100㎛ to complete the case for a mobile terminal.

Here, it is preferable to add imidazole (1-allyl-3-methylimidazolioum chloride) to the dispersed mixture. That is, 1.0 to 4.0 wt% of imidazole is added to 99 to 96 wt% of the dispersed mixture, and then stirred at 500 to 1000 RPM, followed by injection or extrusion into a mold having a predetermined shape to manufacture a case for a mobile terminal.

In this case, for dispersibility of imidazole, it is preferable to add methyl ethyl ketone (MEK) as a solvent in a 1: 1 weight ratio to the mixture.

The case for a mobile terminal manufactured by this process contains 5 to 15% or more of antistatic raw material powder per unit surface area, and has a 0.72 to 1.9 kV charging potential and a 10 ¹⁰ Ω / cm ² to 10 ¹² / cm ² surface resistance. Therefore, due to the high concentration of metal powder, high dispersibility, and hydrophilicity by imidazole, the surface resistance can be minimized, and thus, excellent overall rigidity and excellent antistatic performance can be expected.

Another aspect of the present invention relates to a method for manufacturing a case such as a rear protective body or a front liquid crystal body constituting a portable electronic terminal, a case for a portable terminal manufactured through the steps (A) to (E) as shown in FIG. It is about.

Steps (C) to (E) in the manufacturing method of the present invention is the same as the manufacturing method of one side, so a separate description is omitted. That is, in step (A), a master batch insulating resin prepared by mixing any one or two or more of PVC, PC, PE, ABS, and acrylic, which are synthetic resins for a case, is prepared. Step (B) is to prepare a master batch conductive resin for preventing static electricity.

Here, the conductive resin is a high functional resin having chemical, electrical, and mechanically specific properties. The conductive resin is not added with a metal to a polymer resin for transferring electricity, but has conductivity as an organic material such as polyacetylene or polyaniline.

Since the conductive resin can be directly mixed with the synthetic resin for the case, the process of powdering the metal and modifying the metal particles, which are carried out on one side and the other side, can be omitted, thereby reducing the overall manpower and improving quality.

Hereinafter, the effect of the antistatic function of the case according to the present invention on the basis of the experiment.

Experiment 1

The first experiment is to determine the dispersion index (Dispersion Index) of the case manufactured by the method according to one aspect of the present invention.

Experimental Method

The dispersion index of Example 1 in which the metal is pulverized with a grinder and formed into particulate powder, and the metal is pulverized with the grinder, is prepared into particulate powder, and then modified by the air-jet dry milling machine, the dispersion index of Example 2 is prepared.

<Sample Production>

90 wt% of the PE case raw powder and 10 wt% of the aluminum (Al) antistatic raw powder were mixed, and then heated and stirred to form a 1 cm thick plate. The prepared plate was cut equally to 100 g weight and randomly extracted three pieces of each example.

<Experimental conditions>

The same volume of sample was placed in an electric furnace and then heated to 300 ° C. and burned until there was no soot. And the weight (g) of the aluminum contained in the ash remaining burned was measured.

<Experiment Result>

sample Aluminum weight (g) Example 1-1 12.5 Example 1-2 11.8 Example 1-3 13.2 Example 2-1 15.8 Example 2-2 16.2 Example 2-3 14.5

As a result, Example 1 of the simple powder-treated antistatic raw material powder was measured with an average weight of 12.5g, and Example 2 of the antistatic raw material powder modified with air-jet was measured with an average weight of 15.5g. That is, although the Examples achieve all the high concentration and high dispersion of 5 to 15% or more of the target, it can be seen that Example 1 is inferior to Example 2.

<Experiment 2>

The second experiment is to determine the static electricity of the case manufactured by the method according to another aspect of the present invention.

Experimental Method

The experimental method is to compare the static electricity of Example 1 coated with the dispersion mixture on the surface of the case and Example 2 coated on the surface of the case after the imidazole is added to the dispersion mixture.

<Sample Production>

The case was made of PC, and the mixture was stirred by mixing the aluminum (Al) powder powder with 98% by weight of the UV ink adhesive 2.0% by weight, and then sprayed the mixture on the surface of the manufactured case and coated with a thickness of 100 μm. The size of the PC case was molded into a plate having a thickness of 1 cm, and the produced plates were cut into 3 cm 3 equally and randomly extracted. In Example 2, the mixture was coated by imidazole 1.0 wt%, 2.0 wt%, 3.0 wt%, and 4.0 wt%.

<Experimental conditions>

The static electricity level was measured after 10 seconds under the condition that the friction cloth was rubbed on the surface of the extracted sample for 30 seconds. Electrostatic measurement was performed using an electrostatic field meter (FMX-004, simco-ion, Japan), and the humidity environment was set to 30%.

<Experiment Result>

sample Imidazole addition amount (% by weight) (kV) Example 1 - 6.17 Example 2-1 One 1.9 Example 2-2 2 1.1 Example 2-3 3 0.76 Example 2-4 4 0.72

Experimental results showed that 1.17kV, imidazole, 1.9kV, 1.1kV, 0.76Kv and 0.72kV were added when the untreated coating was added with 1%, 2%, 3%, and 4% of imidazole. That is, as the imidazole concentration is increased, the static electricity level decreases, and when the imidazole concentration is 3% or more, the value of the charge potential is 1 kV or less, which indicates that the antistatic effect is excellent.

Even when imidazole is not added, the antistatic effect can be seen because of the hydrophilicity of the OH (hydroxy group) of the coating agent.

Here, when the value of the surface resistance is 10 ¹⁰ Ω or less, it is a very good state in which charging does not occur, and when it is 10 ¹² Ω or more, there is no antistatic effect. When the value of the surface resistance is 10 ¹⁰ Ω or less, the value of the charge potential is 0.1 to 1 kV, and when it is 1 kV or less, it can be regarded as excellent in the antistatic effect.

As described above, the present invention is to reduce the size of the ground metal particles into ultra-fine particles and to modify the shape of the particles into crushed oval or square, and then freeze-hardened and then changed into ice-water, which is excellent overall due to the high concentration and high dispersibility of the metal powder. Excellent antistatic performance can be expected.

Claims (7)

delete (A) preparing a case for a mobile terminal by injecting or extruding a synthetic resin into a mold having a predetermined shape; (B) preparing an antistatic raw material powder in which a conductive metal is pulverized and particles are modified; Preparing an adhesive in which any one or two or more of isopropyl alcohol, UV ink, and solvent ink are prepared, and (D) the antistatic raw material powder is prepared in an amount of 98-99.2% by weight of the adhesive in an amount of 0.8-2.0%. %, And mixing the blended mixture to disperse the antistatic raw material powder, and (E) applying the dispersed mixture to the prepared case to a thickness of 10 to 100㎛ to complete the case for the mobile terminal In the manufacturing method of the terminal case,
Step (B) further comprises the step of transforming the shape of the particles from spherical to crushed oval or square while converting the conductive metal to an ultra-fine particle of 0.3 to 4.0㎛ by grinding the conductive metal with an air-jet dry mill,
Step (C) further comprises applying a polymer material of alkyltrialkoxysilane or acrylate to the surface of the case produced through step (A) in the preparation of the adhesive to improve the adhesion in the subsequent application step and,
Step (D) is followed by stirring the mixture consisting of the antistatic raw material powder and the adhesive at 300 to 500RPM, and then into a freezer at a fixed size of 5 cm 3 to cool below freezing to grind the freeze-cured mixture by an ice water machine. Further comprising re-modifying the particles of the unmodified metal powder together with the quantitative use in the step,
Step (E) is set after stirring at 500 to 1000 RPM by adding 1.0 to 4.0% by weight of imidazole (1-allyl-3-methylimidazolioum chloride) having both cations and anions to 99 to 96% by weight of the dispersed mixture. Injection or extrusion into a mold having a shape, but having an antistatic function further comprising adding a mixture of methyl ethyl ketone (MEK), which is a solvent, in a 1: 1 weight ratio for dispersibility of imidazole. Method of manufacturing a case for a mobile terminal.
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