KR100776231B1 - Polyurethane-based composition for metal vapor deposition - Google Patents

Abstract

A polyurethane composition for conductive metal vapor deposition is provided to produce polyurethane primer solution with good spraying property and to prevent a thin film from being separated by maintaining good adhesion between the polyurethane primer and the metal thin film. A polyurethane composition for conductive metal vapor deposition is composed of a polycarbonate or polymethylmethacrylate plastic layer; an ester polyurethane primer layer formed by spraying polyurethane solution on the plastic layer; and a metal deposited layer formed by depositing one selected from conductive shielding copper, nickel, chrome, gold, and silver on the polyurethane primer layer. Polyurethane consists of polyurethane resin of 70~80wt.% and acryl polymer of 20~30wt.%. The polyurethane solution is two-liquid type polyurethane solution consisting of polyurethane of 3~30wt.%, a hardening agent of 5~40wt.%, and a solvent of 30~92wt.%.

Description

Polyurethane composition for conductive metal deposition {POLYURETHANE-BASED COMPOSITION FOR METAL VAPOR DEPOSITION}

The present invention relates to a polyurethane composition for conductive metal deposition, and more particularly, to a polyurethane resin composition which is primer-coated on the surface of a device so that a metal deposition layer for shielding electromagnetic waves can be deposited on the device.

At present, many electromagnetic waves are emitted from electronic devices such as microwave ovens, TVs, radios, computers, and mobile phones.

Electromagnetic emission is manifested as phenomena such as noise and communication disturbances, and also affects the human body. As the severity is added in modern times, interest in electromagnetic shielding is increasing, and the necessity thereof is increasing. In addition, although the case of the device has conventionally used metal, plastic has been used due to the trend of miniaturization and productivity improvement. However, plastics are electronically transparent, so the electromagnetic wave radiation is large, so countermeasures are urgent.

As a method for blocking electromagnetic waves, metal spraying, vacuum deposition, plating, and conductive paints are used, and recently, materials such as conductive plastics have been actively developed.

The method using a conductive paint has been widely used because of the advantages of easy operation and mass production. The conductive paint coating method, as introduced in the domestic patent application No. 10-2000-0083111 or U.S. Patent No. 4,518,524, etc., is a method of producing a coating by using a metal of a small particle size, and then a method of forming a coating film by coating. . However, the conductive coating method is a form in which metal particles are dispersed in a coating polymer, and the coating film is not dense at the surface, so the resistance of the coating film has a surface resistance value of 25 microns to 30 ohms, which has a large resistance value. . In addition, in order to increase the electromagnetic wave blocking effect of the conductive paint, there has been a problem that an expensive metal such as silver is required in excess.

On the other hand, a method of shielding electromagnetic waves by coating a thin film of a metal having excellent electrical conductivity in a vacuum deposition method on the structure of the electronic device (e.g., injection molded plastic cell phone case) that generates electromagnetic waves. However, there is a problem that the interfacial adhesion between the polymer resin of the injection molding and the metal layer of the conductive film for shielding electromagnetic waves is weak. In order to solve the problem of weak adhesion between the metal layer and the injection molding, a method of applying acrylic or ABS resin or UV curable paint with a primer and depositing a metal thereon has been developed.

Korean Patent No. 0387663 issued to Lee Kyung Hee introduces a method of improving electromagnetic shielding properties by plating metal on engineering plastic, which is difficult to electrolessly plate. More specifically, surfaces of engineering plastics that are difficult to electrolessly plate as polybutylene terephthalate (PBT), polypropylene (PP), polyester (PE), polyamide (PA), acrylic or a mixture of two or more thereof Spray coating of ABS resin and / or UV-curable paint to form a primer layer, and dry plating such as electroless plating or vacuum deposition, sputtering, ion plating, etc., but the substrate is polycarbonate (PC) resin or ABS resin The electroless plating is difficult to engineering plastics that do not include, the conductive laminate is copper, nickel, chromium, gold, silver, etc., and the primer material for improving the bonding strength between the substrate and the conductive laminate is ABS resin And / or a primer applicable to UV (ultraviolet) curable paint, and after applying the primer to the substrate by electroless plating A method for imparting and techniques. However, such an ABS resin or UV curable paint has a problem that it is difficult to evenly coat the plastic metal surface, and also has a problem that the adhesive strength of the metal layer formed thereon is also lowered because it is not easily adhered to the solid state engineering plastic.

Accordingly, there is a continuing need for a primer capable of providing good adhesion between the deposited metal layer and the lower resin layer and forming a uniform film.

It is an object of the present invention to provide a polyurethane for primer that provides good adhesion between the metal layer to be deposited and the underlying resin layer.

It is another object of the present invention to provide a method for producing a polyurethane for primer that provides good adhesion between the metal layer to be deposited and the bottom resin layer.

Still another object of the present invention is to provide a polyurethane composition for primers which is spray coated on a plastic substrate to form a primer on which a metal layer is deposited.

It is another object of the present invention to provide the use of polyurethane as a primer to impart good adhesion between the metal layer and the lower resin layer.

Still another object of the present invention is to provide an electromagnetic wave shielding layer structure including a polyurethane primer layer for metal deposition.

The electromagnetic shielding layer according to the present invention for achieving the above object is

Plastic layer;

A polyurethane primer layer formed on the plastic layer; And

A metal thin film layer formed on the polyurethane primer layer;

Characterized in that it comprises a.

In the present invention, the plastic layer is a variety of plastic products used as an internal and external agent of the electronic device. In the practice of the present invention, the plastic may be a plastic product in which the metal thin film layer is not formed without the primer layer, or the adhesive strength and peeling resistance of the formed thin film layer are weak, and the improvement of the peeling resistance is required. In a preferred embodiment of the present invention, the plastic is polycarbonate or polymethylmethacrylate used as the material of the mobile phone case.

In the present invention, the polyurethane primer layer is a polyurethane resin layer formed by coating on a plastic layer. In the present invention, the polyurethane resin forming the primer layer is a resin layer having a bonding force with the deposited metal and the lower plastic so that the deposited metal layer may have peeling resistance.

In the present invention, the polyurethane primer layer is a primer resin layer containing 70% or more of polyurethane resin so that the primer properties can be maintained. In one embodiment of the present invention, the polyurethane primer layer is a polyurethane containing a part of the acrylic polymer compatible with the polyurethane to adjust the hardness of the coating film. In a preferred embodiment of the present invention, the acrylic polymer is preferably 30% by weight, preferably 25% by weight, more preferably 20% by weight of the primer layer. In a preferred embodiment of the present invention, the acrylic polymer is a single or mixed polymer of acrylic monomers, for example, acrylic monomers made of C2-C8 carbon such as methyl methacrylate, butyl acrylate, ethylhexyl acrylate.

In the present invention, the polyurethane resin layer is more preferably used a polyester-based polyurethane having good bonding strength to the metal and the lower plastic to be deposited. In the practice of the present invention, the polyester-based polyurethane is a polyurethane prepared by reacting a polyol prepared by reacting a polyol and an acid with a polyisocyanate can be used a conventional polyester-based polyurethane, commercially available It is possible. In a preferred embodiment of the present invention, the ester-based polyurethane may be prepared using an ester polyol prepared by reacting a polyol such as ethylene glycol, neopentyl glycol, and hexanediol with an acid such as isophthalic acid, adipic acid, or azelic acid. .

In the present invention, the polyurethane coating layer may be formed on the plastic layer in various ways. In a preferred embodiment of the present invention, the polyurethane primer layer is formed by spray drying a polyurethane solution.

In the present invention, the spray-drying polyurethane solution may be a one-component type crosslinked by a crosslinking agent mixed with a two-component type crosslinked by a separate crosslinking agent.

In the present invention, the polyurethane solution is preferably configured to satisfy the properties of the dried film, that is, spray suitability, after the urethane solution is spray dried. In a preferred embodiment of the present invention, the two-component polyurethane solution is preferably composed of 3-30% by weight of polyurethane, 5-40% by weight of hardener, and 30-92% by weight of solvent. In another embodiment of the present invention, the one-component polyurethane solution is preferably made of 3-30 wt% polyurethane, 70-97 wt% solvent.

In the present invention, the solvent in which the polyurethane is dissolved is selected from C6-C12 aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone, and ethers such as ethyl acetate, which are sprayed and evaporated upon drying.

The present invention, in one aspect, consists of a polyurethane composition for primers comprising 3-30% by weight of polyurethane.

In the present invention, the polyurethane composition for a primer is a composition in which polyurethane is dispersed in a solution so as to form a coating layer by spraying on a plastic layer. The use of the curing agent may be determined in the solution depending on the type of polyurethane, for example, one-component or two-component polyurethane.

In the practice of the present invention, the polyurethane solution may be a two-component type polyurethane in which a curing agent is used separately, and preferably, by reacting the ester-based polyol and polyisocyanate so as to have a flat surface after spraying. It may consist of 3-30% by weight of polyurethane, 5-40% by weight of hardener, 30-92% by weight of solvent.

In the present invention, the ester-based polyol may be prepared by reacting a polyol such as ethylene glycol, neopentyl glycol, hexanediol and an acid such as isophthalic acid, adipic acid, and azelic acid. In one embodiment of the invention, the ester-based polyol may be used in combination with other polyols, such as acrylic polyol, preferably it is preferred to use more than 70% by weight of the ester polyol.

In the practice of the present invention, the polyurethane is an ester polyol prepared by reacting a polyol such as ethylene glycol, neopentyl glycol, hexanediol and an acid such as isophthalic acid, adipic acid or azelic acid, such as ethyl acetate or methyl ethyl ketone. It is prepared by adding a solvent with a catalyst such as tin and then reacting with a polyisocyanate such as toluene diisocyanate. In a preferred embodiment of the present invention, the polyurethane is adjusted to the amount of ester polyol and toluene diisocyanate such that hydroxyl groups are formed at the terminal.

In the present invention, the polyurethane solution may include a one-component type polyurethane that contains a curing agent and does not use a separate curing agent, and preferably, an ester-based polyol and a polyisocyanate so as to have a flat surface after spraying. It consists of 3-30% by weight of one-component polyurethane, 70-97% by weight of a solvent formed by the reaction.

In the practice of the present invention, the polyurethane is an ester polyol prepared by reacting a polyol such as ethylene glycol, neopentyl glycol, hexanediol and an acid such as isophthalic acid, adipic acid or azelic acid, such as ethyl acetate or methyl ethyl ketone. It is prepared by adding a solvent with a catalyst such as tin and then reacting with a polyisocyanate such as toluene diisocyanate. In a preferred embodiment of the invention, the polyurethane is adjusted to the amount of ester polyol and toluene diisocyanate so that isocyanate groups are formed at the ends. By adding and reacting amines to neutralize the terminal isocyanate of the prepared polyurethane, it is formed into a polyurethane that can be cured by reacting alone without a curing agent.

In one aspect, the present invention is a polyurethane for metal vacuum deposition primer, the polyurethane is made of a polyurethane, characterized in that the ester-based polyurethane.

In the present invention, the ester-based polyurethane is a polyurethane prepared by reacting a polyol such as ethylene glycol, neopentyl glycol, hexanediol and an ester polyol prepared by reacting an acid such as isophthalic acid, adipic acid or azelic acid, It is also available for purchase.

Provided is a method for producing a polyurethane for a metal vacuum deposition primer.

In one aspect of the invention, as a method for producing an electromagnetic shielding layer,

Spray coating a primer on the plastic substrate,

Wherein the primer is a one-component polyurethane solution is a one-component polyurethane solution consisting of 3 to 30% by weight polyurethane, 70 to 97% by weight solvent or

A two-component polyurethane solution consisting of 3-30 weight percent polyurethane, 5-40 weight percent curing agent, and 30-92 weight percent solvent;

Drying the polyurethane to form a spray coating layer; and

Depositing a metal on the spray coating layer

Characterized in that comprises a.

Through the following examples, the present invention will be described in detail. The examples described below are merely to illustrate the invention and are not intended to limit the invention.

Example

Ester polyol manufacturers

Example 1

Equipped with a clean 4L flask, stirrer, mantle, cooling tube, and water separator, 229 g of ethylene glycol, 136 g of neopentyl glycol, 365 g of 1.6 hexanediol, 413 g of isophthalic acid, and 363 g of adipic acid. 234g of azelic acid is added and 0.3g of Ti (tributyltin) is added to raise the temperature to around 130 ° C. At this time, the temperature was continuously increased while slowly adding nitrogen, and the reaction was continued until the acid value became 0.1 or less while maintaining the temperature at 250 ° C. Average molecular weight after completion of reaction 3600. A transparent polyester diol having an acid value of 0.1 or less was prepared.

Example (2)

Prepared in the same manner as in Example 1, 170g of ethylene glycol, neopentylglycol 570g, terephthalic acid 208g, isophthalic acid 138g, adipic acid 611g was added, 0.3g of Ti (tributyltin) was added to raise the temperature to around 130 ℃ to melt When dehydration starts slowly, while slowly adding nitrogen, the temperature is continuously raised and maintained at 250 ° C until the acid value becomes less than 0.1. Average molecular weight after completion of reaction 1950. Acid value. A transparent polyester diol of 0.1 or less was prepared.

Production of two-component polyurethane

Example (3)

Cleanly prepared 4 L flask and stirrer. A mantle cooling tube was mounted and the like (1) diol 1750g, ethyl acetate 593g, methyl ethyl ketone 593g, dibutyltin dilaurator 0.3g, and 29.2 g of toluene diisocyanate were added while stirring and the mixture was heated at 90 ° C. 60 wt% solids in time. A resin with a viscosity of 1500 cps was prepared.

Example (4)

With a 4L flask prepared clean. A stirrer, a mantle, a cooling tube, and the like were added, and 950 g of diol (3), ethyl acetate 343 g, methyl ethyl ketone 313 g, and 0.3 g of dibutyl tin dilaurate were added thereto, followed by stirring. The reaction was carried out for 5 hours to prepare a resin having a solid content of 60 wt% viscosity 800 cps.

Example (5)

Cleanly prepared 4L flask, mantle, stirrer, cooling tube, etc., DT-2014 Molecular weight 2000 Ethylene glycol 1.4 Butanediol, Adiponic polymer diol 950 ethyl acetate 343g, methyl ethyl ketone 313g, dibutyl tin dilaurate 0.3 30.5 g of toluene diisocyanate was added while stirring with stirring, and the mixture was reacted at 90 ° C. for 5 hours to prepare a resin having a solid content of 60 wt% viscosity 900 cps.

Example (6)

A cleanly prepared 4 L flask, mantle, stirrer, and cooling tube were mounted to 950 g of polytetramethyl ether glycol molecular weight 2000. 343 g of ethyl acetate, 313 g of methyl ethyl ketone, and 0.3 g of dibutyl tin dilaurate were added thereto, and 30.5 g of toluene diisocyanate was added while stirring, followed by reaction at 90 ° C. for 5 hours to prepare a resin having a solid content of 60 wt% viscosity 1200 cps.

Comparative Example (1)

Toluene was added by stirring a cleanly prepared 4L flask, a stirrer, a mantle, and a cooling tube, adding 1550 g of diol No. 1, 5 g of trimetholpropane, 560 g of ethyl acetate, 510 g of methyl ethyl ketone, and 0.3 g of dibutyltin dilaurate. 29.2 g of diisocyanate was added thereto and reacted at 90 ° C. for 5 hours to prepare a resin having a solid content of 60 wt% viscosity of 5200 cps.

Comparative Example (2)

A diol 950g in Example 2 was equipped with a cleanly prepared 4L flask, an agitator, a mantle, a cooling tube, and the like. Ethyl acetate. 343 g. 298 g of methyl ethyl ketone. 0.3 g of dibutyl tin dilaurate. 16.3 g of toluene diisocyanate was added while stirring, and the mixture was reacted at 90 ° C. for 5 hours to prepare a resin having a solid content of 60 wt% viscosity of 4300 cps.

Deposition test

The polyurethane composition prepared in the above Examples was prepared by spraying a polyisocyanate trimer having a solid content of 30% by weight with a solution such as toluene, ethyl acetate, methyl ethyl ketone, xylene, and the like as a curing agent as shown in Table 1 below. Prepared.

 Table 1.

Item Example (3) Example (4) Example (5) Example (6) Comparative Example 1 Comparative Example 2 Polyurethane 30 30 30 30 30 30 toluene 20 20 20 20 20 20 Ethyl acetate 15 15 15 15 15 15 Methyl ethyl ketone 20 20 20 20 20 20 Xylene 5 5 5 5 5 5 Hardener 10 10 10 10 10 10 synthesis 100 100 100 100 100 100

The mixing unit in Table 1 is% by weight
The prepared spray composition was spray coated on the plastic side of the polycarbonate material, and then dried at 75 ° C. for 1 hour. After drying, spray-coated polycarbonate was placed in a vacuum chamber and subjected to aluminum deposition at 70 ° C. for 1 hour.

The prepared product was tested for spray suitability, adhesion, gloss, leveling, vacuum deposition, electrical resistance, saline resistance, and crack resistance. The test results are listed in Table 2 below.

Table 2

Example (3) Example (4) Example (5) Example (6) Comparative Example (1) Comparative Example (2) Spray aptitude ◎ ◎ ◎ ○ X X Adhesion ◎ ◎ ◎ ○ ○ ○ Gloss ○ ○ ○ ◎ ○ ○ Leveling ◎ ◎ ○ ○ △ △ Vacuum deposition ◎ ◎ ◎ ◎ △ △ Electrical resistance ◎ ◎ ◎ ○ △ △ Saline resistance ◎ ◎ ○ ○ △ △ Crack Testability ◎ ◎ ◎ ○ △ △

(◎: Very good, ○: Good, △: Normal, X: Poor)
Manufacture of one component type polyurethane

Example (7)

     A clean 2 L flask, a mantle, a stirrer, and a cooling tube were mounted, and 410 g of diol No. 1 in Example (1). Ethyl acetate. 210 g. 0.3 g of dibutyl tin dilaurate. After adding and stirring 140 g of methyl ethyl ketone, 19 g of toluene diisocyanate was added while stirring and the reaction was carried out at 90 ° C. for 4 hours, followed by cooling to 60 ° C. and 200 g of ethyl acetate 250 g of methyl ethyl ketone. 7 g of isophorone diamine is mixed and dropped for about 20 minutes and then heated to 80 ° C. for 2 hours. After completion of the reaction, a resin with a solid content of 35 wt% viscosity 1200 cps was prepared.

Example (8)

 Cleanly prepared 2 L flask, mantle, stirrer, cooling tube, and polycarbonate diol molecular weight 1000. 228 g. 120 g of ethyl acetate. 140 g of methyl ethyl ketone. 0.3 g of dibutyl tin dilaurate was added. 38 g of toluene diisocyanate was added while stirring. The reaction was maintained at 90 ° C. for 4 hours, and then cooled to 60 ° C. to 150 g of ethyl acetate. 150 g of methyl ethyl ketone. 120 g of isopropyl alcohol and 8.2 g of isophorone diamine were mixed and dropped for about 20 minutes. After the completion of the reaction, a resin having a solid content of 29 wt% viscosity of 890 cps was prepared.

Example (9)

Cleanly prepared 2 L flask, stirrer, mantle, cooling tube, polytetramethyl ether glycol molecular weight 1000. 228 g. 120 g ethyl acetate. 140 g of methyl ethyl ketone. 0.3 g of dibutyl tin dilaurate was added and 38 g of toluene diisocyanate was added with stirring to maintain the mixture at 90 ° C. for 4 hours, and then cooled to 60 ° C. and 150 g of ethyl acetate. 120 g of methyl ethyl ketone. 120 g of isopropyl alcohol and isophorone diamine. After mixing 6.9g and dropping for about 20 minutes, the temperature is raised to 80 ℃ and maintained for 2 hours. After the completion of the reaction, a resin having a solid content of 29 wt% viscosity of 2800 cps was prepared.

Comparative Example (10)

Cleanly prepared 2 L flask, stirrer, mantle, cooling tube, polytetramethyl ether glycol molecular weight 1000.165g, trimethylolpropane 8g, ethyl acetate 105g, methyl ethyl ketone 120g, 0.3g dibutyl tin dilaurator and stirred While 38 g of toluene diisocyanate was added and the reaction was carried out at 90 ° C. for 4 hours, the reaction mixture was cooled to 60 ° C., and 130 g of ethyl acetate, 120 g of methyl ethyl ketone, 120 g of isopropyl alcohol, and 3.5 g of ethylene diamine were dropped for about 20 minutes. The temperature is raised to 0 ° C and the reaction is maintained for 2 hours. After completion of the reaction, a resin having a solid content of 26 wt% viscosity 5600 cps was prepared.

Comparative Example (11)

A clean 2 L flask, a mantle, a stirrer, and a cooling tube were installed, and a polypropylene glycol molecular weight of 1000.228 g, ethyl acetate 120 g, methyl ethyl ketone 140 g, and dibutyl tin dilaurate were added thereto, and 38 g of toluene diisocyanate was added while stirring. After 4 hours of holding at 90 ° C., the mixture was cooled to 60 ° C., 150 g of ethyl acetate, 120 g of methyl ethyl ketone, 120 g of isopropyl alcohol, and 6.9 g of isophorone diamine were dropped and heated to 80 ° C. for 2 minutes. Retain time. After the reaction was completed, a resin having a solid content of 29 wt% and a viscosity of 1900 cps was prepared.

Deposition Test

The polyurethane composition prepared in the above Examples was mixed with a solution of toluene, ethyl acetate, methyl ethyl ketone, xylene, and the like to prepare a spray composition.

Table 3

Item Example (7) Example (8) Example (9) Comparative Example (10) Comparative Example (11) Polyurethane solution 45 55 55 62 55 toluene 35 25 25 23 30 Ethyl acetate 15 15 15 15 10 Xylene 5 5 5 5 5 Sum 100 100 100 100 100

The mixing unit in Table 3 is weight%
The prepared spray composition was spray coated on the plastic side of the polycarbonate material, and then dried at 75 ° C. for 1 hour. After drying, spray-coated polycarbonate was placed in a vacuum chamber and subjected to aluminum deposition at 70 ° C. for 1 hour.

The prepared product was tested for spray suitability, adhesion, gloss, leveling, vacuum deposition, electrical resistance, saline resistance, and crack resistance. The test results are listed in Table 2 below.

Table 4

Example 7 8 9 Comparison 10 Compare 11 Spray aptitude ◎ ◎ ○ X ◎   Adhesion ◎ ◎ ○ ○ X  Gloss ○ ◎ ◎ △ X Leveling ◎ ◎ ○ ○ ◎ Vacuum deposition ◎ ◎ ◎ △ △ Electrical resistance ◎ ◎ ○ △ △ Saline resistance ◎ ◎ ○ △ △ Crack Testability ◎ ◎ ○ △ △

(◎: Very good, ○: Good, △: Normal, X: Poor)

According to the present invention, a polyurethane primer solution based on a polyester polyol capable of preventing the peeling phenomenon between the metal thin film layer and the underlying plastic in the electromagnetic shielding layer has been provided. The polyurethane primer solution according to the present invention has good spray aptitude so that the conventional spray coating can be used as it is. Polyurethane primer according to the present invention can be prevented from peeling off the formed thin film is good adhesion to the metal thin film formed on the top.

Claims (13)

Polycarbonate or polymethylmethacrylate plastic layer, An ester-based polyurethane primer layer formed by spraying a polyurethane solution on the plastic layer, and Metal deposition layer selected from conductive shielding copper, nickel, chromium, gold or silver deposited on the polyurethane primer layer Electromagnetic shielding layer comprising a. delete The electromagnetic shielding layer according to claim 1, wherein the polyurethane is a resin consisting of 70 to 80% by weight of polyurethane resin and 20 to 30% by weight of acrylic polymer. delete The electromagnetic wave shielding layer according to claim 1, wherein the polyurethane solution is a two-component polyurethane solution composed of 3 to 30% by weight of polyurethane, 5 to 40% by weight of a curing agent, and 30 to 92% by weight of a solvent. The electromagnetic wave shielding layer according to claim 1, wherein the polyurethane solution is a one-component polyurethane solution comprising 3-30 wt% polyurethane and 70-97 wt% solvent. The electromagnetic wave shielding layer according to claim 5 or 6, wherein the polyurethane is made of a polyol prepared by an ester condensation reaction. The method of claim 7, wherein the ester polyol is prepared by reacting a polyol selected from the group consisting of ethylene glycol, neopentyl glycol, hexanediol and an acid selected from the group consisting of isophthalic acid, adipic acid, and azelic acid. Electromagnetic shielding layer. The electromagnetic wave shielding layer according to claim 5 or 6, wherein the solvent is selected from the group consisting of C6-C12 aromatic hydrocarbons, ketones, esters and ethers. delete delete delete delete