KR102408014B1 - Masking paint for plating - Google Patents

Abstract

The present invention discloses a masking paint for plating having excellent chemical resistance and electrical insulation.
The masking paint for plating according to the present invention is based on 100 parts by weight of a polyvinyl chloride (PVC, PolyVinylChloride)-based resin, 10 to 50 parts by weight of a cellulose acetate butyrate (CAB, CelluloseAcetateButyrate)-based resin, and an ethylene vinyl acetate (EVA, EthyleneVinylAcetate)-based resin Contains 10 to 50 parts by weight of a resin and a solvent, wherein the solvent is 50 to 2000 parts by weight of a ketone-based solvent, 50 to 50 parts by weight of an ester-based solvent, based on 100 parts by weight of a polyvinyl chloride (PVC, PolyVinylChloride)-based resin ~1000 parts by weight, ether (ether)-based solvent 50 to 1000 parts by weight, aldehyde (aldehyde)-based solvent is characterized in that it contains 50 to 1000 parts by weight.

Description

Masking paint for plating

The present invention relates to a masking paint for plating applied to a portion not to be plated on an object to be plated during a plating process, and more particularly, to a masking paint for plating having excellent chemical resistance and electrical insulation by controlling the composition of the paint.

In general, electroplating, chemical plating, hot-dip plating, etc. are performed to form a coating film on the object to be plated. Plating is used for parts for many uses, such as automobiles, aircraft, and computer parts, and has the advantage of giving various metal textures and excellent durability and appearance.

As a method of plating a part requiring partial plating, there is a method of manually attaching a masking tape to a portion not to be plated and then performing plating. This has a problem in that the workability is poor and the defect rate is high because the tape must be cut by manually matching each of the tapes to the parts where plating is unnecessary during the plating process.

On the other hand, in order to solve this problem, a method of developing a masking protective ink or a masking paint and spraying and applying them to a portion not to be plated is used.

As a background art related to the present invention, there is an ink composition for masking a printed circuit board disclosed in Korean Patent Application Laid-Open No. 10-2004-0079240 (published on September 14, 2004).

It is an object of the present invention to provide a masking paint for plating having excellent chemical resistance and electrical insulation.

In the plating process according to the present invention for achieving the above object, a masking paint for plating is applied to a portion not to be plated on a body to be plated, and the paint is polyvinyl chloride (PVC, PolyVinylChloride) based on 100 parts by weight of a resin. , Cellulose Acetate Butyrate (CAB, CelluloseAcetateButyrate)-based resin 10-50 parts by weight, ethylene vinyl acetate (EVA, EthyleneVinylAcetate)-based resin 10-50 parts by weight, and a solvent, and the solvent is polyvinyl chloride (PVC, PolyVinylChloride)-based resin. Based on 100 parts by weight of the resin, 50 to 2000 parts by weight of a ketone solvent, 50 to 1000 parts by weight of an ester solvent, 50 to 1000 parts by weight of an ether solvent, 50 parts by weight of an aldehyde solvent It is characterized in that it contains ~1000 parts by weight.

The weight average molecular weight of the polyvinyl chloride-based resin may be 1Х10 ⁴ to 1Х10 ⁶ .

The paint is characterized in that it further comprises at least one of 10 to 200 parts by weight of a cellosolve solvent and 10 to 200 parts by weight of an aromatic hydrocarbon solvent based on 100 parts by weight of the polyvinyl chloride-based resin.

The paint may further include an additive comprising at least one of 0.1 to 20 parts by weight of a colorant and 0.1 to 20 parts by weight of a plasticizer based on 100 parts by weight of the polyvinyl chloride-based resin.

The masking paint for plating according to the present invention is a one-component type paint and has excellent workability during the plating process, and has excellent chemical resistance and electrical insulation properties.

In addition, the masking paint for plating of the present invention has excellent adhesion to the object to be plated, and does not affect the plating layer and the object to be plated during the plating process.

Advantages and features of the present invention, and methods for achieving them, will become apparent with reference to the embodiments described below in detail. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, the masking paint for plating according to a preferred embodiment of the present invention will be described in detail as follows.

The masking paint for plating of the present invention is a paint applied to a non-plated portion of an object to be plated during the plating process, and has the effect of reducing the plating area and shortening the plating process time because plating does not proceed during the plating process. In particular, the masking paint for plating is harmless to the object to be plated during the plating pre-treatment process and the plating etching process, and the tin, silver, palladium, etc. In addition, the weight of the material is reduced after plating, and the cost is reduced during the plating process and the appearance is excellent.

The masking paint for plating of the present invention is based on 100 parts by weight of a polyvinyl chloride (PVC, PolyVinylChloride)-based resin, 10 to 50 parts by weight of a cellulose acetate butyrate (CAB, CelluloseAcetateButyrate)-based resin, and an ethylene vinyl acetate (EVA, EthyleneVinylAcetate)-based resin 10 to 50 parts by weight and a solvent.

The solvent is based on 100 parts by weight of a polyvinyl chloride (PVC, PolyVinylChloride)-based resin, 50 to 2000 parts by weight of a ketone-based solvent, 50 to 1000 parts by weight of an ester-based solvent, 50 to 50 parts by weight of an ether-based solvent ~1000 parts by weight, including 50 to 1000 parts by weight of an aldehyde-based solvent.

The masking paint for plating according to the present invention is used as a one-component paint without dilution.

Hereinafter, the role and content of each component included in the masking paint for plating according to the present invention will be described.

Polyvinyl chloride (PVC, PolyVinylChloride)-based resin is a major component of paint, and has excellent characteristics such as colorless and transparent, alkali resistance, acid resistance, and electrical insulation. A variety of known PVC resins may be used, and it is preferable to use a copolymerized vinyl resin prepared by including 10 to 15% of vinyl acetate in a vinyl chloride resin. The copolymer vinyl resin is suitable as a resin for paints because of its excellent flexibility and adhesion.

In the case of the PVC-based resin, the number constituting the polymer, that is, the degree of polymerization is approximately 750 to 2700.

It is preferable that it is 1Х10 ⁴ - 1Х10 ⁶ , and, as for a weight average molecular weight, it is more preferable that it is 4Х10 ⁴ - 3Х10 ⁵ . If the weight average molecular weight is less than 1Х10 ⁴ , the physical properties of the coating film may be deteriorated. Conversely, if it exceeds 1Х10 ⁶ , the PVC-based resin is not well soluble in the solvent, so it may be difficult to form a paint.

The masking paint for plating is based on 100 parts by weight of a polyvinyl chloride (PVC, PolyVinylChloride)-based resin, 10 to 50 parts by weight of a cellulose acetate butyrate (CAB, CelluloseAcetateButyrate)-based resin, 10 to 50 parts by weight of an ethylene vinyl acetate (EVA, EthyleneVinylAcetate)-based resin 50 parts by weight. These resins are included in the paint to show physical properties such as dispersibility, weather resistance, and chemical resistance.

Cellulose Acetate Butyrate (CAB)-based resins have excellent moldability and durability, and have excellent compatibility with polyvinyl chloride-based resins.

In addition, the CAB-based resin is a resin excellent in compatibility and dispersibility when adding a colorant to a paint, and is preferably added in an amount of 50 parts by weight or less. More specifically, it is preferable that the CAB resin is contained in an amount of 10 to 50 parts by weight, the effect of the addition is insufficient when it is less than 10 parts by weight, and when it exceeds 50 parts by weight, the physical properties of the coating film are deteriorated.

Ethylene vinyl acetate (EVA, EthyleneVinylAcetate)-based resin is a copolymer of ethylene and vinyl acetate, and is a copolymer in which vinyl acetate is randomly polymerized on the backbone of polyethylene. The biggest feature of EVA resin is high flexibility and compatibility, but it is weak in flexibility and compatibility with an etchant in which chromic acid and sulfuric acid are mixed. The EVA resin is preferably included in an amount of 10 to 50 parts by weight. If it is less than 10 parts by weight, the effect of the addition may be insufficient and the flexibility of the coating film may be reduced, and if it exceeds 50 parts by weight, the content increases and only the cost increases without the effect of physical properties.

The solvent contained in the masking paint for plating of the present invention is based on 100 parts by weight of a polyvinyl chloride (PVC, PolyVinylChloride)-based resin, 50 to 2000 parts by weight of a ketone-based solvent, 50 to 1000 parts by weight of an ester-based solvent parts, 50 to 1000 parts by weight of an ether-based solvent, and 50 to 1000 parts by weight of an aldehyde-based solvent.

Specifically, 50-100 parts by weight of a ketone-based solvent, 50-100 parts by weight of an ester-based solvent, 50-100 parts by weight of an ether-based solvent, 50-100 parts by weight of an aldehyde-based solvent Included.

These solvents can increase the solubility of PVC-based resins according to polarity and the degree of hydrogen bonding, and have characteristics of easy painting and spraying depending on the type of solvent.

A variety of known ketone solvents may be used, for example, methyl ethyl ketone, acetone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, methyl- n-pentyl ketone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, di-iso-butyl ketone, trimethylnonanone, cyclohexanone, 2-hexanone, methylcyclohexanone, and the like may be used. The paint is preferably included in an amount of 50 to 2000 parts by weight of a ketone-based solvent based on 100 parts by weight of the polyvinyl chloride-based resin. When included in an amount of less than 50 parts by weight, the viscosity of the coating material may increase and adhesion of the coating film may be reduced.

The ester solvent is, for example, diethyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, iso-acetic acid propyl, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, Benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether, acetate ethylene glycol monoethyl ether, etc. can be used. The ester-based solvent is preferably included in the paint in an amount of 50 to 1000 parts by weight. When included in less than 50 parts by weight, it may be difficult to control the viscosity of the paint. Conversely, when it is included in excess of 1000 parts by weight, the drying time of the coating film is prolonged when the coating film is formed, and workability is deteriorated.

As the ether-based solvent, a heterocyclic compound composed of 4 carbon atoms and 1 oxygen atom, a cyclic ether formed by hydrogenation of furan, etc. may be used. For example, tetrahydrofuran (THF) and the like may be used. The ether-based solvent is preferably included in an amount of 50 to 1000 parts by weight in the paint. When included in less than 50 parts by weight, the solubility of the PVC-based resin may decrease, and it may be difficult to control the viscosity of the paint. When included in excess of 1000 parts by weight, a silking (coupling of a coating film, silking) phenomenon occurs during spray operation, thereby reducing workability.

The aldehyde-based solvent may be, for example, acetaldehyde or butylaldehyde, and is preferably included in an amount of 50 to 1000 parts by weight. When included in less than 50 parts by weight, the solubility of the PVC-based resin may decrease and it may be difficult to control the viscosity of the paint. When included in excess of 1000 parts by weight, a silking phenomenon may occur during spray operation, which may decrease workability, and the aldehyde-based solvent may be easily oxidized, which may cause a problem in the storability of the paint.

As such, when the solvent is added to the masking paint for plating in an appropriate range, the viscosity of the paint can be adjusted and workability can be improved through the dissolution relationship between the resin and the solvent.

In addition, the masking paint for plating of the present invention further comprises at least one of 10 to 200 parts by weight of a cellosolve solvent and 10 to 200 parts by weight of an aromatic hydrocarbon solvent based on 100 parts by weight of the polyvinyl chloride-based resin. can do.

Although the cellosolve solvent cannot completely dissolve the PVC resin presented above, it is used as an auxiliary solvent, so an appropriate content is required. As the solvent, for example, butyl cellosolve, methyl cellosolve, benzyl cellosolve and the like may be used. The cellosolve solvent may be included in the paint in an amount of 10 to 200 parts by weight, and when included in an amount of less than 10 parts by weight, the additive effect is insufficient. Conversely, when included in excess of 200 parts by weight, compatibility with the PVC-based resin may not be excellent, so that the dispersibility of the paint and the physical properties of the coating film may be deteriorated.

Examples of the aromatic hydrocarbon solvent include ethers such as 1,2-dimethoxyethane, diethyl ether, methyl-t-butyl ether, and dioxane, benzene, toluene, and xylene. These solvents are non-polar and insoluble in water and dissolve carbon compounds well, so they have excellent compatibility with EVA-based resins and the like, and are suitable as solvents for paints. The aromatic hydrocarbon-based solvent may be included in the paint in an amount of 10 to 200 parts by weight, thereby further improving the physical properties and workability of the paint. If it is out of the above range, only the cost is increased without the effect of the addition.

In addition, the masking paint for plating may further include an additive including at least one of 0.1 to 20 parts by weight of a colorant and 0.1 to 20 parts by weight of a plasticizer based on 100 parts by weight of the polyvinyl chloride-based resin.

The toner is added to impart clarity and color to the paint, and for example, carbon black, mica powder, etc. may be used in consideration of the color. The toner includes a toner having conductive properties, and when such a toner is used, it may conduct during the plating process.

Therefore, in order to prevent conduction, it is preferable to select a raw material for a toner and add it in an appropriate amount. The toner may be included in an amount of 0.1 to 20 parts by weight, and when it is out of the above range, it is difficult to express a desired color and a problem of a decrease in hiding power may occur during painting.

The plasticizer is used to impart flexibility to the coating film and has excellent compatibility with polyvinyl chloride-based resins. The plasticizer may be, for example, phthalate, an eco-friendly material, such as diisononyl ester (diisononyl ester). The plasticizer may be included in an amount of 0.1 to 20 parts by weight, and when it is out of the above range, the physical properties of the coating film are lowered to lower the chemical resistance of the etching solution and the like.

In addition to the added components, if necessary, various additives such as an antifoaming agent, a brightening agent, a matting agent, and a corrosion inhibitor may be added in a range that does not reduce the overall physical properties of the coating film.

The above-mentioned components are mixed at room temperature to prepare a paint, and a paint film is formed by spraying the paint on a portion of the body to be plated that is not to be plated by a spray method. The coating film may have a thickness of approximately 10 to 20 μm, and the coating film may exhibit a light gray color depending on the composition of the paint. If necessary, the surface of the coating film may be wiped with a solvent such as isopropyl alcohol to remove foreign substances. In addition, in order to prevent contaminants from remaining on the surface of the coating film or generation of static electricity, the surface treatment may be performed on the surface of the coating film using an air shower or an ionizer.

As described above, the masking paint for plating of the present invention is a paint applied to a non-plated portion of a body to be plated during the plating process, and has excellent chemical resistance and electrical insulation properties by adjusting the composition of the paint. In particular, the masking paint for plating of the present invention is not affected by the plating layer and the object to be plated during the plating pre-treatment process and the plating etching process, and is not plated after the plating process, so that a desired portion can be treated without plating. In addition, since the coating film has excellent adhesion to the object to be plated, there is an effect that the coating film can be permanently maintained.

As described above, specific examples of the masking paint for plating will be described as follows.

1. Manufacture of paint

[Table 1]

The content of the resin, solvent, colorant and plasticizer was described in parts by weight based on 100 parts by weight of the PVC resin.

2. Methods for evaluating physical properties and their results

Five ABS specimens for plating were prepared, and paints prepared according to Examples 1 to 3 and Comparative Examples 1 to 4 of [Table 1] were prepared. The prepared paint was applied to the non-plated part of the body to be plated by a spray method to form a 10 μm-thick coating film, and then the physical properties were tested.

1. Adhesion was measured in accordance with KS F 4249, and 30kgf/cm ² or more was indicated as excellent and less than as average.

2. Alkali resistance was measured after immersion in 5% sodium hydroxide aqueous solution at room temperature for 96 hours. If it was the same as the initial state, it was indicated as "excellent", when cracks and discoloration occurred at 50% or less, "normal", and when cracks and discoloration occurred at 50% or more, "bad" was indicated.

3. Acid resistance was measured after immersion in 5% hydrochloric acid aqueous solution at room temperature for 96 hours. If it was the same as the initial state, it was indicated as "excellent", when cracks and discoloration occurred at 50% or less, "normal", and when cracks and discoloration occurred at 50% or more, "bad" was indicated.

4. For electrical insulation, breakdown voltage (%) was measured using ASTM D149. If the breakdown voltage is more than 60%, it is indicated as excellent, and if it is less than 60%, it is indicated as normal.

5. Paint storability was confirmed after the paint was stored in a tin container at room temperature for one week. If the state of the paint was the same as the initial state, it was indicated as "excellent", and when discoloration and agglomeration occurred, it was indicated as "normal".

6. To determine whether or not to be plated, paint is applied to the non-plated part of the body to be plated, and the plating process is performed to check whether or not to plated. When plating was not performed, "excellent" was indicated, and when plating was performed, it was indicated as "normal".

[Table 2]

○: Excellent, △: Average, Х: Poor

Referring to Tables 1 and 2, it can be seen that Examples 1 to 3, which satisfy the composition and content presented in the present invention, are excellent in physical property measurement results.

On the other hand, in the case of Comparative Examples 1 to 4 that do not include all of the compositions presented in the present invention or are out of content, it can be confirmed that the physical properties are usually poor as a result of measurement.

Therefore, the masking paint for plating of the present invention has the effect of reducing the plating area during the plating process to shorten the plating process time, reduce the weight of the material, and have excellent chemical resistance and electrical insulation properties.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, but may be manufactured in a variety of different forms, and those of ordinary skill in the art to which the present invention pertains will appreciate the technical spirit of the present invention. However, it will be understood that the invention may be embodied in other specific forms without changing essential features. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

Claims (4)

A masking paint for plating that is applied to the non-plated part of the body to be plated during the plating process,
The paint is
Based on 100 parts by weight of a polyvinyl chloride (PVC, PolyVinylChloride)-based resin, 10-50 parts by weight of a cellulose acetate butyrate (CAB, CelluloseAcetateButyrate)-based resin, 10-50 parts by weight of an ethylenevinyl acetate (EVA, EthyleneVinylAcetate)-based resin, and a solvent including,
The solvent is based on 100 parts by weight of a polyvinyl chloride (PVC, PolyVinylChloride)-based resin, 50 to 2000 parts by weight of a ketone-based solvent, 50 to 1000 parts by weight of an ester-based solvent, 50 parts by weight of an ether-based solvent ~1000 parts by weight of a masking paint for plating, characterized in that it contains 50 to 1000 parts by weight of an aldehyde-based solvent.
The method of claim 1,
The weight average molecular weight of the polyvinyl chloride-based resin is a masking paint for plating, characterized in that 1Х10 ⁴ to 1Х10 ⁶ .
The method of claim 1,
The paint for plating, characterized in that it further comprises at least one of 10 to 200 parts by weight of a cellosolve solvent and 10 to 200 parts by weight of an aromatic hydrocarbon solvent based on 100 parts by weight of the polyvinyl chloride-based resin masking paint.
The method of claim 1,
The paint is a masking paint for plating, characterized in that it further comprises an additive comprising at least one of 0.1 to 20 parts by weight of a colorant and 0.1 to 20 parts by weight of a plasticizer based on 100 parts by weight of the polyvinyl chloride-based resin.