KR101115745B1 - A Black Coloring Resin Coated Steel Sheet, Black Coloring Resin Composition Having Anti-Fingerprint Property and An Adhesive Resin Composition - Google Patents

Abstract

The present invention relates to a black resin steel sheet having improved anti-fingerprint, a black resin composition used therefor, and an adhesive resin composition for improving adhesion between the steel sheet and the black resin coating film. According to the present invention, the steel sheet; And 20 to 40 parts by weight of the main resin-melamine-based curing agent composition, 2 to 6 parts by weight of carbon black pigment, 2 to 6 parts by weight of matting agent, 2 to 6 parts by weight of titanate compound, and at least one of the front and rear surfaces of the base steel sheet. There is provided a black resin steel sheet comprising a black resin coating film formed of a black resin composition containing 0.5 to 2 parts by weight of a fingerprint additive. In addition, the adhesive composition comprising 5 to 15 parts by weight of the black resin composition and the polyurethane resin-melamine-based curing agent composition, 1 to 4 parts by weight of the silane coupling agent, 1 to 4 parts by weight of the metal silicate compound, and 0.5 to 2 parts by weight of the titanate compound. A resin composition is provided. The black resin steel sheet of the present invention has excellent anti-fingerprint, processability, adhesion, electrical conductivity and electromagnetic shielding properties, and is suitable for use as a panel for an electronic device, in particular, an outer panel.

Black resin steel sheet, processability, adhesion, electrical conductivity, electromagnetic shielding, external panel of electronic equipment, anti-fingerprint additive

Description

A Black Coloring Resin Coated Steel Sheet, Black Coloring Resin Composition Having Anti-Fingerprint Property and An Adhesive Resin Composition}

The present invention relates to a black resin steel sheet having improved anti-fingerprint, a black resin composition and adhesive resin composition used therein, and more particularly, to a black resin steel sheet having improved anti-fingerprint, and an anti-fingerprint improving agent used therein. The present invention relates to an adhesive resin composition containing an improved black resin composition and a resin steel sheet and an adhesive force between the black resin coating film.

Black resin steel sheet has excellent corrosion resistance, fingerprint resistance, solvent resistance, and the surface is also beautiful, and is widely used for interior and exterior plates of home appliances and computers.

On the other hand, according to the recent high performance, miniaturization and high functionality of electronic devices, shortening of lifespan and malfunction of devices due to harmful electromagnetic waves generated in electronic component circuits are problematic. Therefore, the black resin steel sheet requires not only fingerprint resistance but also excellent surface electrical conductivity, and steel sheets used for external panels require more excellent designability, processability, adhesion, scratch resistance, and the like.

Conventional PCM (pre-coated metal) coated steel sheet used for home appliances is formed of a three-layer coating film consisting of pretreatment, undercoat and topcoat, and is a thick film having a thickness of more than 20 μm. In addition, due to the limitation of the thick film coating by the roll coating or curtain coating method has a disadvantage of low productivity.

In order to solve this problem, a low cost type home appliance steel sheet having excellent productivity has been provided by minimizing the thickness of the coating film and improving heat dissipation, processability and coating film adhesion by improving the physical properties of the coat and the top coat resin. However, such a steel sheet is limited to use for home appliances of deep processing due to the thinning of the film thickness, and has a disadvantage of being easily contaminated when used as an outer plate due to poor anti-fingerprint.

Therefore, there is a demand for a steel sheet having excellent anti-fingerprint properties, and further, an anti-fingerprint steel sheet having excellent coating film adhesion, productivity, workability, electrical conductivity, and electromagnetic shielding properties with the steel sheet is required.

The present invention is to solve the above problems, according to one embodiment of the present invention, a black resin steel sheet having excellent anti-fingerprint is provided.

According to another embodiment of the present invention, a black resin steel sheet having not only fingerprint resistance but also excellent workability, adhesion, electrical conductivity and electromagnetic shielding property is provided.

According to yet another embodiment of the present invention, an anti-fingerprint black resin composition is provided that provides excellent anti-fingerprint to a steel sheet.

Furthermore, according to another embodiment of the present invention, there is provided an adhesive resin composition which provides the steel sheet with excellent workability, adhesion, electrical conductivity and electromagnetic shielding properties.

In one aspect of the present invention,

Steel plate; And

20-40 parts by weight of the main resin-melamine-based curing agent composition, 2-6 parts by weight of carbon black pigment, 2-6 parts by weight of matting agent, 2-6 parts by weight of titanate compound, and at least one surface of the base steel sheet. A black resin coating film formed of a black resin composition containing 0.5 to 2 parts by weight of at least one anti-fingerprint additive selected from the group consisting of silicone-based compounds such as dimethyltetramethoxy disiloxane, dodecamethylpenta siloxane and dimethyl polysiloxane and a modified acrylic resin. There is provided a black resin steel sheet comprising a.

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In another aspect of the present invention,

Holding steel plate;

5-15 parts of polyurethane resin-melamine-based curing agent composition, 1-4 parts by weight of silane coupling agent, 1-4 parts by weight of metal silicate compound, and 0.5-2 parts by weight of titanate compound on at least one surface of the base steel sheet An adhesion improving coating film formed of an adhesive resin composition comprising; And

20-40 parts by weight of the main resin-melamine-based curing agent composition, 2-6 parts by weight of carbon black pigment, matting agent 2-6, on the base steel sheet on the front or rear surface or the adhesive resin coating film on the front and / or rear surface where no adhesive film is formed. Part by weight, 2 to 6 parts by weight of titanate compound and at least one kind of anti-fingerprint additive selected from the group consisting of silicone-based compounds such as dimethyltetramethoxy disiloxane, dodecamethylpenta siloxane and dimethyl polysiloxane and modified acrylic resins 0.5 to 2 There is provided a black resin steel sheet comprising a black resin coating film formed of a black resin composition containing a weight part.

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In another aspect of the present invention,

20-40 parts by weight of the main resin-melamine-based curing agent composition, 2-6 parts by weight of carbon black pigment, 2-6 parts by weight of matting agent, 2-6 parts by weight of titanate compound and dimethyltetramethoxy disiloxane, dodecamethylpenta There is provided a black resin composition comprising 0.5 to 2 parts by weight of at least one kind of anti-fingerprint additive selected from the group consisting of silicone-based compounds such as siloxane and dimethyl polysiloxane and modified acrylic resins.

Furthermore, in another aspect of the present invention,

An adhesive resin composition comprising 5 to 15 parts by weight of a polyurethane resin-melamine-based curing agent composition, 1 to 4 parts by weight of a silane coupling agent, 1 to 4 parts by weight of a metal silicate compound, and 0.5 to 2 parts by weight of a titanate compound is provided.

The black resin steel sheet according to one embodiment of the present invention exhibits excellent fingerprint resistance by a black resin coating film including anti-fingerprint additives formed on the front and / or rear surfaces of the steel sheet, and is suitable for use as an electronic panel, in particular, an outer panel. will be. The black resin steel sheet according to one embodiment of the present invention has a beautiful appearance by having a semi-gloss color. In addition, the steel sheet exhibits further improved workability, adhesion, electrical conductivity and electromagnetic shielding property by the adhesion improving coating film further formed on the front and / or rear surface of the base steel sheet. In addition, it exhibits surface electric resistance of 0.1 mPa or less, and is excellent in excellent electrostatic earth resistance.

Hereinafter, the black resin steel sheet, the anti-fingerprint black resin composition, and the adhesive resin composition according to the embodiments of the present invention will be described in more detail.

The black resin steel sheet according to the present invention has a fingerprint-resistant black resin coating film formed on at least one surface of the front and rear surfaces of the base steel sheet, thereby showing more improved fingerprinting by the black resin coating film. The anti-fingerprint black resin coating film may be formed of a black resin composition containing a main resin-melamine-based curing agent composition, a carbon black pigment, a matting agent, a titanate compound, and an anti-fingerprint additive. The anti-fingerprint black resin composition which is applied to the base steel sheet to form an anti-fingerprint black resin film to impart anti-fingerprint to the steel sheet is also provided by one embodiment of the present invention.

The main resin-melamine-based curing agent composition as one component constituting the black resin composition includes a main resin and a melamine-based curing agent. The main resin is not particularly limited, but polyester resins, epoxy resins, polyurethane resins, acrylic resins and the like can be used. The said main resin can be used individually or in mixture of 2 or more types. It is preferable to use the thing of the weight average molecular weights 4,000-15,000 as said main resin. If the weight average molecular weight is less than 4,000, the solvent resistance of the coating film is insufficient, and if the weight average molecular weight exceeds 15,000, the storage stability of the solution is insufficient.

The melamine curing agent is not limited thereto, but melamine, butoxymethyl melamine, hexamethoxymethyl melamine, trimethoxymethyl melamine, and the like may be used. The melamine-based curing agent may be used alone or in mixture of two or more thereof.

In the main resin-melamine-based curing agent composition, the main resin and the melamine-based curing agent may be blended in a 10: 1-5 weight ratio, preferably in a 10: 2-4 weight ratio. When the blending ratio of the main resin and the melamine curing agent is out of 10: 1-5, a dense film is not formed and the physical properties of the coating film are lowered.

The main resin-melamine-based curing agent composition may be blended in an amount of 20-40 parts by weight with the blending amount of the other components constituting the black resin composition. If the blending ratio of the main resin-melamine-based curing agent composition is less than 20 parts by weight, the corrosion resistance and solvent resistance are insufficient, and if it exceeds 40 parts by weight, the content of the resin is too high, thus the viscosity is increased and the physical properties of the coating film are not preferable.

The carbon black pigment, which is a black pigment to be blended into the black resin composition, may be blended in an amount of 2 to 6 parts by weight, preferably 3 to 5 parts by weight, with the blending amount of other components constituting the black resin composition. If the carbon black pigment is less than 2 parts by weight, it is difficult to obtain sufficient endothermic and / or heat dissipation characteristics and high hiding rate of the base steel sheet. Although the average particle diameter of the carbon black pigment is not particularly limited, it is preferable to use one having an average particle size of about 10 to 100 nm in view of dispersibility and the like. Examples of the carbon black pigments include, but are not limited to, the Erox ™ series, the Printex ™ series, the Highblack ™ series and the like from Ebonics (Germany). The carbon black pigments may be used alone or in combination of different kinds.

In addition, the matting agent may be blended with 2 to 6 parts by weight of the above compounding amount of the other components constituting the black resin composition. If the matting agent content is less than 2 parts by weight, it is not possible to obtain the gloss of a desirable range in home appliances, and if it exceeds 6 parts by weight, the gloss is too low and the viscosity is high, so that it is difficult to obtain a beautiful appearance. As the matting agent, but not limited to this, for example, silica, magnesium oxide, zirconia, alumina and titania may be used. The quencher can be used alone or in mixture of two or more.

Furthermore, a titanate compound is mix | blended with a black resin composition for the corrosion resistance improvement of a black resin coating film. The titanate compound may be blended with 2-6 parts by weight of the above compounding amount of the other components constituting the black resin composition. Even if the titanate compound is less than 2 parts by weight, insufficient to secure sufficient high corrosion resistance, and more than 6 parts by weight, it is not preferable because it is difficult to expect a further improvement in physical properties due to the increase in the amount used. Examples of such titanate compounds may include, but are not limited to, isopropylditriethanolamino titanate, lactic acid titanium chelate and titanium acetylacetonate. These titanate compounds may be used in one kind or in a mixture of two or more kinds.

The black resin composition may be blended in an amount of 0.5 to 2 parts by weight, preferably 2 parts by weight, of the blending amount of the other components constituting the black resin composition and the anti-fingerprint additive so as to show rubbing on the steel sheet. If the anti-fingerprint improving additive content is less than 0.5 parts by weight, it is difficult to obtain excellent anti-fingerprint, and if it exceeds 2 parts by weight, the solution storage property is poor. Examples of anti-fingerprint improving additives include, but are not limited to, silicone-based additives such as dimethyltetramethoxy disiloxane, dodecamethylpenta siloxane, dimethyl polysiloxane, and modified acrylic resins, which may be used alone or in mixtures. . The anti-fingerprint additive improves the water repellency of the coating film and serves to protect the coating film from fingerprints or various contaminants.

The black resin composition may be applied to the main resin-melamine-based curing agent composition, carbon black pigment, matting agent, titanate compound, and anti-fingerprint additive, as well as to further improve physical properties of the steel sheet treated using the black resin composition. Accordingly, at least one additive such as a wax, a curing catalyst, a pigment aggregation inhibitor, an antifoaming agent, a phosphate additive, and a silane compound may be further blended. These optional additives are generally known in the art and their blending ratios are not particularly limited and those skilled in the art can use these additives as appropriately blended as necessary.

 The black resin composition includes 20 to 40 parts by weight of the main resin-melamine-based curing agent composition, 2 to 6 parts by weight of carbon black pigment, 2 to 6 parts by weight of matting agent, 2 to 6 parts by weight of titanate compound, and 0.5 to 2 additives of fingerprinting agent. Preferably, the black resin composition comprises 20 to 40 parts by weight of the main resin-melamine-based curing agent composition, 2 to 6 parts by weight of carbon black pigment, 2 to 6 parts by weight of matting agent, and titanate per 100 parts by weight of black resin composition. The compound may contain 2 to 6 parts by weight, anti-fingerprint additive 0.5 to 2 and the residual solvent. At this time, toluene, xylene, isopropanol, solvent naphtha, cellosolve, cellosolve acetate, butyl cellosolve, etc. may be used as the residual solvent. The solvent may be used alone or in a mixture of two or more thereof.

The viscosity of the black resin composition is controlled by the content of the solvent, and the amount of the solvent is not particularly limited, and a person skilled in the art may appropriately adjust the amount of the solvent according to techniques commonly used in the art. The amount of the solvent is not limited to this, but considering the coating amount control and adhesion of the black resin composition, for example, the amount is about 20 to 80 seconds to be discharged from the Dean cup (DIN, 53211). It is desirable to be able to adjust it.

The solid content of the black resin composition is preferably adjusted by using a solvent to be 50-60% by weight in consideration of heat dissipation characteristics and fingerprint resistance by the black resin composition.

The black resin composition in one embodiment of the present invention, may be applied to at least one surface of the front and rear of the steel sheet. That is, the black resin composition may be applied to only the front or rear surface of the steel sheet or to both the front and rear surfaces to form an anti-fingerprint black resin coating film.

The black resin composition is coated on the front and / or rear surface of the base steel sheet and dried to form an anti-fingerprint black resin film (also referred to herein as a 'top coat'). An electro galvanized steel sheet may be used as the steel sheet.

The black resin coating film is formed so as to have a dry coating thickness of 5 to 20 µm, preferably 7 to 15 µm. When the dry coating thickness of the black resin coating film is less than 5 μm, the hiding power, processability and solvent resistance of the black resin coating film are poor, and when it exceeds 20 μm, the manufacturing cost increases and the productivity is low, which is not preferable.

The black resin composition may include a front and / or rear surface of the steel sheet in a manner generally known in the art; Or it may be coated on the adhesion improving film described later, it is not limited to this, for example, a bar coater, a roll coater or a curtain coater method may be used.

Drying of the coated black resin composition can also be done by any method generally known in the art. Although drying is not limited to this, it can carry out by a hot air heating system, an infrared heating system, or an induction heating system.

The black resin composition is preferably dried at 180-260 ° C. at PMT (Peak Metal Temperature). Although not limited thereto, for example, in the case of a hot air heating method, the black resin composition may be dried by hot air treatment for 10 to 50 seconds at a temperature of 200 to 340 ° C. In the case of the induction heating method, the black resin composition may be dried for 5 to 20 seconds in a frequency range of 5 to 50 MHz and a power of 3 to 15 KW.

On the other hand, the black resin steel sheet is not only the adhesion between the steel sheet and the black resin coating film, but also to improve the adhesion, the electrical conductivity and electromagnetic shielding property to the front and / or rear surface of the base steel sheet to improve the adhesion (hereinafter referred to as " May also be referred to as a 'coat'. The adhesive improvement coating film not only increases the adhesion between the base steel sheet and the black resin coating film, but also imparts workability, electrical conductivity, and electromagnetic wave shielding properties to the steel sheet, regardless of whether the black resin coating film is formed. It can be formed on the back. In one embodiment of the present invention, it is preferable that an adhesive improvement coating film is formed on the rear surface of the base steel sheet. In another embodiment of the present invention, when the black resin film is formed on only one surface of the steel sheet, the surface of the steel sheet on which the black resin film is not formed may be formed in consideration of the processability, corrosion resistance, electrical conductivity, etc. of the black resin sheet. desirable. According to one embodiment of the present invention, an adhesive improvement coating film is formed on both sides of the base steel sheet, and a black resin steel sheet having a black resin coating film formed on one surface of the adhesion improvement coating film is provided.

On the other hand, in the case of a steel plate including a black resin coating film (top coat), the adhesive improvement coating film (undercoat) is located between the base steel sheet and the black resin coating film (top coat). 1 is a side cross-sectional view of the black resin steel sheet is formed on the front and rear of the base steel sheet according to an embodiment of the present invention, the adhesion improving film is formed and the black resin coating film is formed on the adhesive improvement coating film on the front. FIG. 2 is a side cross-sectional view of the black resin steel sheet in which the adhesive improvement coating film and the black resin coating film are formed on both the front and rear surfaces of the steel sheet.

In one embodiment of the present invention, the adhesion improving coating film further formed on the front and / or rear of the holding steel sheet may be formed of the following adhesive resin composition. The adhesive resin composition described later is also provided by one embodiment of the present invention.

The adhesive resin composition includes a polyurethane resin-melamine-based curing agent composition, a silane coupling agent, a metal silicate compound, and a titanate compound. In general, while the inorganic component has good adhesion between the steel sheet and the resin layer, poor ductility tends to cause coating film cracks during steel sheet processing such as deep processing. On the other hand, the organic resin is excellent in ductility, but has a disadvantage in weak adhesion with the steel sheet is preferably an organic-inorganic resin mixed with an inorganic component, the adhesive resin composition according to an embodiment of the present invention the organic component and the inorganic component the interaction It is formulated in consideration of.

The polyurethane resin-melamine-based curing agent composition blended into the adhesive resin composition serves to impart excellent adhesion, processability and ductility to the steel sheet. In particular, the polyurethane resin-melamine curing agent composition is excellent in adhesion with the black resin coating film, which is a steel sheet and a top coating film, to prevent coating film cracks generated during processing of home appliance parts. In addition, the polyurethane resin-melamine-based curing agent composition exhibits excellent compatibility and solution stability with other components of the adhesive resin composition as an alkali-based resin such as an inorganic compound to be added to the adhesive resin composition.

The said polyurethane resin-melamine type hardening | curing agent composition is mix | blended with the said compounding quantity of the other component which comprises an adhesive resin composition and 5-15 weight part. When the polyurethane resin-melamine-based curing agent composition is blended in less than 5 parts by weight, the adhesive strength is excellent, but the ductility is low, the deep workability is insufficient, and when the content exceeds 15 parts by weight, the resin content is too high, poor adhesion and corrosion resistance.

The polyurethane resin-melamine-based curing agent composition may be used by mixing a polyurethane resin: melamine-based curing agent in a 10: 1 to 5 weight ratio as a composition of the polyurethane resin and the melamine-based curing agent. The polyurethane resin-melamine-based curing agent composition having the above composition ratio is preferable in terms of corrosion resistance and solvent resistance of the coating film.

As the polyurethane resin, it is preferable to use a weight average molecular weight of 10,000 to 25,000. If the weight average molecular weight is less than 10,000, the solvent resistance of the coating film is insufficient, and if the weight average molecular weight is more than 25,000, the storage stability of the solution is insufficient. The melamine curing agent is not limited thereto, but melamine, butoxymethyl melamine, hexamethoxymethyl melamine, trimethoxymethyl melamine, and the like may be used. The melamine-based curing agent may be used alone or in mixture of two or more thereof.

The silane coupling agent in the adhesive resin composition serves to improve corrosion resistance by forming a three-dimensional inorganic polymer chain structure with various organic materials and inorganic materials. The said silane coupling agent can be mix | blended with the said compounding quantity of the other component which comprises an adhesive resin composition at 1-4 weight part. If the amount of the silane coupling agent is less than 1 part by weight, the effect of improving the corrosion resistance according to the silane coupling agent is not sufficient. If the amount exceeds 4 parts by weight, the quality is deteriorated due to problems such as stability of the solution. Examples of the silane coupling agent are not particularly limited thereto, but include, for example, 3-aminopropyltriepoxy silane, 3-glycidoxypropyltrimethoxy silane, 3-methoglyoxypropyltrimethoxy silane, N- ( (beta) -aminoethyl)-(gamma)-aminopropyl trimethoxysilane, (gamma)-glycidoxy propyl triethoxysilane, (gamma)-glycidoxy citrimethyl dimethoxysilane, etc. are mentioned. The silane coupling agents may be used alone or in a mixture of two or more thereof.

In the adhesive resin composition, the metal silicate compound is coated on the steel sheet to form a three-dimensional network structure to impart corrosion resistance to the steel sheet. Such a silicate compound has excellent corrosion resistance as well as a high bonding strength with a zinc plating layer and is widely used for undercoat, and serves as a crosslinking role for bonding the plating layer and the top black resin coating layer. However, when the metal silicate compound is used in a small amount, the intended physical properties are not sufficiently exhibited, and when a large amount of the metal silicate compound is used, the bonding strength of the coating film is rather weakened. Therefore, in consideration of the crosslinking role of the silicate compound, the provision of corrosion resistance, and the adhesiveness with the coating film, it is blended in an amount of 1 to 4 parts by weight with other components constituting the adhesive resin composition. Examples of the metal silicate compound include, but are not limited to, at least one compound selected from the group consisting of lithium polysilicate, sodium polysilicate, potassium polysilicate and colloidal silica.

The titanate compound serves to promote crosslinking and curing of the adhesive resin composition and to improve the corrosion resistance of the coating film. In order to optimally express the crosslinking and curing properties and corrosion resistance by the titanate compound, it may be blended in an amount of 1 to 4 parts by weight with respect to the blending amount of other components constituting the adhesive resin composition. Examples of the titanate compound include, but are not limited to, isopropylditriethanolamino titanate, titanium titanate lactate and titanium acetylacetonate. The titanate compound may be used alone or in a mixture of two or more thereof.

The adhesive resin composition may include 5 to 15 parts by weight of a polyurethane resin-melamine-based curing agent composition, 1 to 4 parts by weight of a silane coupling agent, 1 to 4 parts by weight of a metal silicate compound, and 0.5 to 2 parts by weight of a titanate compound. Preferably, the adhesive resin composition is 5 to 15 parts by weight of the polyurethane resin-melamine-based curing agent composition, 1 to 4 parts by weight of the silane coupling agent, 1 to 4 parts by weight of the metal silicate compound, 0.5 titanate compound per 100 parts by weight of the adhesive resin composition. It may contain -2 weight part and remainder pure water.

A defoamer may be further mix | blended with the said adhesive resin composition as needed. This is common to those skilled in the art, and those skilled in the art can select and use appropriately according to needs.

The adhesive resin composition is preferably adjusted to have a solid content of 8-20% by weight, preferably 10-16% by weight. If the solid content of the adhesive resin composition is less than 8% by weight, it is not preferable in that an appropriate amount of undercoat is not obtained. If the content of the adhesive resin composition is more than 20% by weight, solution storage property and workability are not good. The adhesive resin composition preferably has a viscosity of 4-10 cps, because it exhibits excellent roll coating workability in this viscosity range. If the viscosity of the adhesive resin composition is less than 4 cps, it is impossible to obtain an appropriate amount of undercoat, and if it exceeds 10 cps, solution storage property and workability are not good.

Remainder other than the component mix | blended with the said adhesive resin composition is pure water, and solid content and viscosity in an adhesive resin composition can be adjusted using pure water. The adhesive resin composition may be prepared by separately preparing an inorganic solution including a silane coupling agent, a metal silicate compound, and a titanate compound, and a resin composition including a polyurethane resin and a melamine-based curing agent, and then mixing and mixing them. Preferred at When the silane or titanate inorganic component is directly mixed with the resin composition, sludge may be generated.

The adhesive resin composition is applied to the front and / or rear surface of the base steel sheet to form an adhesive improvement coating film, and the black resin steel sheet having the adhesive improvement coating film shows not only anti-fingerprint but also excellent processability, adhesion, electric conductivity and electromagnetic shielding property. The excellent electrical conductivity and electromagnetic wave shielding property of the adhesive resin composition are achieved by controlling the amount of the inorganic component and the coating film adhered to the adhesive resin composition to 1,800 mg / m 2 or less.

The adhesive resin composition may be optionally coated on the front side and / or the rear side of the base steel sheet and dried as needed to further form an adhesive improvement coating film.

In consideration of adhesion, corrosion resistance and electrical conductivity, the adhesive resin composition may be coated to have an adhesion amount of 800-1800 mg / m 2 on the front and / or rear surface of the base steel sheet. If the adhesion amount is less than 800 mg / m 2, adhesion and corrosion resistance are insufficient, and if it is more than 1800 mg / m 2, the electrical conductivity is low and not preferable. In addition, the adhesive improvement coating film is formed so that a dry coating film thickness may be 0.5-2 micrometers. Adhesiveness and corrosion resistance are inadequate when the dry coating film thickness of an adhesive improvement coating film is less than 0.5 micrometer, and when it exceeds 2 micrometers, electrical conductivity falls. On the other hand, the dry film thickness of an adhesive improvement coating film is related with the adhesion amount of adhesive resin.

The adhesive resin composition may be coated on a steel sheet by a method generally known in the art, such as the application of the black resin composition described above, but is not limited thereto. For example, a bar coater, a roll coater or Curtain coater methods can be used. Drying of the coated adhesive resin composition may also be carried out by any method generally known in the art as in the case of the black resin composition described above. Although drying is not limited to this, it can carry out by a hot air heating system, an infrared heating system, or an induction heating system.

Coating of the adhesive resin composition is preferably dried at 130 ~ 180 ℃ to PMT (Peak Metal Temperature) in terms of drying efficiency. Although not limited to this, specifically, for example, in the case of a hot air heating system, the adhesive resin composition may be dried by hot air treatment for 5 to 20 seconds at 160 to 340 ° C. ambient temperature. In the case of the induction heating method, the adhesive resin composition may be dried for 3 to 15 seconds in a frequency range of 5 to 50 MHz and a power of 3 to 15 KW.

The black resin steel sheet provided in the embodiment of the present invention includes (1) ① a steel sheet, and ② a black resin coating film formed on at least one surface of the front and rear surfaces of the sheet; (2) (1) the base steel sheet, ② the adhesive resin coating film (coated film) formed on at least one of the front and rear surfaces of the base steel sheet; And (3) a black resin coating film (top coat) formed on the front or rear holding steel sheet on which the adhesive improvement coating film is not formed, or on the adhesive resin coating film on the front and / or back surface. In the black resin steel sheet according to one embodiment of the present invention, the top coat, the top coat and the steel sheet are not limited thereto, but may be, for example, in a laminated form as follows; Rear Top / Steel Plate, Rear Top / Rear Bottom View / Steel Plate, Rear Top View / Rear View Bottom / Steel Plate / Front Bottom View, Rear Top View / Rear View / Steel Plate / Front Top View, Rear Top View / Steel Sheet / Front View, Rear Top View / Steel Sheet / Front View Front View,

Rear view / Steel sheet / Front top view, Rear view / Steel sheet / Front view / Front top view (Figure 1), Steel plate / Front view, Steel plate / Front view / Front top view, Rear view / Rear view / Steel plate / Front view / Front view ( 2).

The black resin steel sheet according to one embodiment of the present invention exhibits excellent anti-fingerprint properties. Furthermore, the black resin steel sheet is not only excellent in workability, adhesion, electrical conductivity and electromagnetic shielding properties, but also has a semi-gloss black beautiful color. Moreover, the steel sheet according to one embodiment of the present invention exhibits the same endothermic and / or heat dissipation characteristics, even though a thin film is formed as compared with the conventional PCM coated steel sheet. Therefore, the black resin steel sheet according to one embodiment of the present invention is suitable for use as a high-end panel in the field of imaging appliances, in which the demand for home appliances, in particular, the demand is rapidly increasing in recent years.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are not intended to limit the present invention.

Example 1

1. Steel Plate

As a steel plate, an electro galvanized steel (EG) galvanized on both sides with a plating amount of 20g / m ² on one side was used.

2. Adhesive resin composition and black resin composition

(1) adhesive resin composition

The adhesive resin composition is 3-aminopropyltriepoxy silane as silane coupling agent, lithium polysilicate as metal silicate compound, isopropylditriethanolamino titanate as titanate compound, and polyurethane resin-melamine based on 100 parts by weight of the adhesive resin composition. 10: 2 parts by weight of the polyurethane resin composition (polyurethane resin and butoxy methyl melamine (melamine curing agent) are blended. The average molecular weight of the polyurethane resin is 20,000), respectively, in the amounts shown in Table 1 below, followed by stirring It was. In the adhesive resin composition, the balance was pure water, and the viscosity was 8 cps.

The adhesive resin compositions of the invention examples and the comparative examples of Table 1 thus prepared were roll-coated on both sides of the galvanized steel sheet so that the dry coating thickness per side became the thickness shown in Table 1 and dried at PMT-160 ° C. An adhesion improving coating film was formed on both sides of the steel sheet. Thereafter, the surface conductivity and the corrosion resistance of the steel sheet having an adhesion improving coating film were measured and shown in Table 1 below. Surface conductivity and corrosion resistance were measured as described in the property evaluation item mentioned later.

On the other hand, the black resin composition of Inventive Example 20 of Table 2 was roll-coated so as to have a dry coating thickness of 15 μm on the entire surface of the steel sheet on which the adhesive improvement coating film of Table 1 was formed, and dried at PMT-220 ° C. to give a black resin coating film. After the formation, the adhesion of the black resin coating film was evaluated and shown in Table 1. Adhesiveness was measured as described in the property evaluation item mentioned later.

[Table 1]

* Acrylic resin-melamine curing agent composition of Comparative Example 7: A polyacrylic resin (average molecular weight 20,000) and butoxy methyl melamine (melamine curing agent) are blended at 5: 1 parts by weight.

As can be seen in Table 1, the drying of 0.5 to 2㎛ using an adhesive resin composition containing a polyurethane resin-melamine-based curing agent composition, a silane coupling agent, a metal silicate and a titinate compound in an amount according to the embodiment of the present invention The adhesion improvement coating film (undercoat) formed by the coating film thickness shows the outstanding surface conductivity, corrosion resistance, and adhesiveness.

(2) black resin composition

The black resin composition was prepared by blending the main resin-melamine curing agent composition, carbon black pigment, quencher, titanate compound, and anti-fingerprint additive in the amounts shown in Table 2 based on 100 parts by weight of the black resin composition. In the black resin composition, as other additives, 1 part by weight of polyethylene wax, 100 parts by weight of black resin composition, 2 parts by weight of paratoluene sulfonic acid as a curing catalyst, 0.5 parts by weight of BYK-170 ^TM pigment aggregation inhibitor of BYK chemie, and phosphate adhesion 0.5 parts by weight of zinc phosphate was added as an enhancer, and a black resin composition was prepared by stirring at a speed of 3000 rpm for 30 minutes with a high speed stirrer containing zirconia balls.

As the carbon black pigment, Printex ^TM (Degussa, Germany) having an average particle diameter of about 10-30 nm was used, and isopropylditriethanolamino titanate was used as the titanate compound. As a matting agent, synthetic silica of Dongyang Steel Chemical Co., Ltd. having an average particle diameter of about 3 μm was used. As the main resin-melamine curing agent composition, a resin composition containing a polyester resin having a weight average molecular weight of 4,000 to 15,000 and a melamine curing agent in a 10: 2 weight ratio was used. Trimethoxymethyl melamine was used as the melamine-based curing agent and dimethyl polysiloxane was used as the anti-fingerprint additive.

On the other hand, the black resin composition was formulated using a thinner (cellosolve acetate) as a solvent so as to have a viscosity of about 30 to 60 seconds when discharged from the Dean cup (# 4, DIN 53211).

The composition of the black resin composition of Table 2 is expressed as parts by weight of the components blended based on 100 parts by weight of the black resin composition. All but additives are thinners as solvents.

TABLE 2

3. Preparation of Steel Plate Specimens

Roll-coated the adhesive resin composition of Inventive Example 7 or Comparative Example 7 of Table 1 so that the dry film thickness of the undercoat (adhesive resin composition) per side on both sides of the base steel sheet was as shown in Table 3 below. It dried at -160 degreeC, and the undercoat which is an adhesive improvement coating film was formed on both surfaces of the steel plate. Thereafter, the black resin composition shown in Table 3 was coated on the steel sheet adhesion improving coating film to have a dry coating thickness shown in Table 3 below, and dried at PMT-230 ° C. to improve adhesion of the front or both sides as shown in Table 3. A top coat film, which is a black resin coat, was formed on the coat film.

4. Property evaluation

(1) surface electrical conductivity

Surface electrical conductivity is shown in Table 1 by measuring the resistance value of the adhesion improved coating surface (undercoat) by using a LORESTA GP (McBC).

[Evaluation Criteria] ◎: Resistance ≤ 0.1mΩ, ○: 0.1mΩ <Resistance <1mΩ, △: Resistance ≥ 1mΩ

(2) bending workability

Bend the surface of the coated and top-coated steel sheet 180 ° and place it in a vise and tighten until it becomes flat. (0, 1, 2 T-bending) After attaching the scotch tape to the bent film, peel off the film. When peeled off, the state which peeled on the tape is evaluated.

[Evaluation standard]

◎: 0, 1, 2 T bends all peeled off, ○: OT bends peeled off only, △: O, 1, 2T bends peeled off.

(3) coating film adhesion

100 sheets of checkerboard-shaped scales were made on the surface of the black resin coating film of the steel sheet at an interval of 1 mm, and after 7 mm of Ericksen processing, the adhesion of the coating film was evaluated by the number of coating films peeling off the tape when the coating film was peeled off with a scotch tape.

[Evaluation standard]

◎: no peeling, ○: 3 or less peelings, △: 3 or more peelings

(4) solvent resistance

After the black resin steel sheet was prepared into a specimen of 50 × 100 mm size, it was determined by the number of times until the coating film was peeled off when rubbed with a force of 1 Kgf with a gauze soaked with methyl ethyl ketone.

[Evaluation standard]

◎: more than 50 times, ○: 20 to 50 times, △: less than 20 times

(5) anti-fingerprint

It was evaluated by measuring the color difference (ΔE) after leaving the top coat film wet in artificial fingerprint solution for 30 minutes.

[Evaluation standard]

(Double-circle): (DELTA) E <0.5, (circle): 0.5 <(DELTA) E <1.0, (triangle | delta): (DELTA) E≥1.0.

(6) heat dissipation

Evaluation of heat dissipation characteristics was measured by manufacturing the test apparatus of FIG. In the test apparatus of FIG. 3, the exterior is made of styrofoam (a), the inside of the styrofoam is lined with aluminum foil (c), and a heater (b) is placed at the bottom center of the test apparatus. On top of the heater (b) was placed a copy protection aluminum plate (f). In the center portion between the heater b and the upper end of the test apparatus, as shown in FIG. The specimen to be measured was placed on the upper part of the opened test apparatus, and the change in the internal temperature of the box was measured. The size of the test apparatus was 200 x 200 x 200 mm.

The black resin steel sheet specimens prepared in each of the inventive examples and the comparative examples were prepared into specimens having a width x length (200 x 200 mm), and then attached and sealed to the opened upper surface (e) of the measuring device. At this time, the black resin coated surface of the steel sheet was attached so as to face the outer surface of the test apparatus. The thermal temperature was evaluated by calculating the internal temperature difference (ㅿ T) between the uncoated electrogalvanized steel sheet and the black resin steel sheet.

(7) gloss

Glossiness measuring equipment of black resin coated surface of each invention and comparative example (model Sheen REF-260)

It was measured at the incident angle of 60 ° using.

(8) corrosion resistance

Corrosion resistance time required to produce 5 area% white rust after spraying 5 ° C NaCl at 35 ℃ and 5% NaCl with an injection pressure of 1 Kg / m ² using a salt spray device (JIS E2731). Evaluated.

[Evaluation standard]

◎: More than 72hrs, ○: 48-72hrs, △: less than 48hrs

◎: more than 120 hrs, ○: 96 to 120 hrs, △: less than 96 hrs

[Table 3] Treatment Conditions and Property Evaluation Results of Underpass and Top Coats

As can be seen from Table 3, the steel sheet of the invention examples 3-1 to 3-12 belonging to the range of the composition and the treatment conditions of the undercoat and top coat are excellent in corrosion resistance, processability, adhesion, solvent resistance , Anti-fingerprint, heat dissipation and gloss.

1 is a side cross-sectional view of a black resin steel sheet formed with an adhesive improvement coating film formed on the front and rear surfaces of the base steel sheet and a black resin coating film formed on the adhesive improvement coating film on the front surface thereof.

Figure 2 is a side cross-sectional view of the black resin steel sheet formed with an adhesive improvement coating film and a black resin coating film on both the front and rear of the steel sheet,

3 is a view showing a device used for measuring the heat radiation characteristics in the embodiment.

  Description of the Related Art [0002]

   a .... styrofoam constituting the box b .... heater

   c .... aluminum foil d .... thermometer

   e .... Measurement specimen f .... Aluminum sheet for copy protection

Claims (18)

Steel plate; And At least one selected from the group consisting of a polyester resin, an epoxy resin, a polyurethane resin, and an acrylic resin on at least one surface of the front and rear surfaces of the base steel sheet, and having a weight average molecular weight of 4,000 to 15,000. -40 parts by weight, carbon black pigment 2-6 parts by weight, matting agent 2-6 parts by weight, titanate compound 2-6 parts by weight and dimethyltetramethoxy disiloxane, dodecamethylpenta siloxane, dimethyl polysiloxane and modified acrylic resin Black resin steel sheet comprising a black resin coating film formed of a black resin composition containing 0.5 to 2 parts by weight of at least one anti-fingerprint additive selected from the group consisting of: Holding steel plate; 5-15 parts of polyurethane resin-melamine-based curing agent composition, 1-4 parts by weight of silane coupling agent, 1-4 parts by weight of metal silicate compound, and 0.5-2 parts by weight of titanate compound on at least one surface of the base steel sheet An adhesion improving coating film formed of an adhesive resin composition comprising; And Improved adhesion A minimum of one selected from the group consisting of polyester resins, epoxy resins, polyurethane resins and acrylic resins on the steel sheet on the front or rear surface where no coating film is formed or on the adhesive resin film on the front and / or rear surface. 20 to 40 parts by weight of the main resin-melamine-based curing agent composition of 4,000 to 15,000, 2 to 6 parts by weight of carbon black pigment, 2 to 6 parts by weight of quencher, 2 to 6 parts by weight of titanate compound, and dimethyltetramethoxy disiloxane, A black resin steel sheet comprising a black resin coating film formed of a black resin composition containing 0.5 to 2 parts by weight of at least one kind of anti-fingerprint additive selected from the group consisting of dodecamethylpenta siloxane, dimethyl polysiloxane and modified acrylic resin. The black resin steel sheet according to claim 1 or 2, wherein the base steel sheet is an electrogalvanized steel sheet. delete The at least one kind of melamine selected from the group consisting of melamine, butoxymethyl melamine, hexamethoxymethyl melamine and trimethoxymethyl melamine according to claim 1 or 2, in the subject resin-melamine-based curing agent composition. Black resin steel sheet, characterized in that the curing agent. The black resin sheet according to claim 1 or 2, wherein the matting agent is at least one selected from the group consisting of silica, magnesium oxide, zirconia, alumina, and titania. The black resin sheet according to claim 1 or 2, wherein the titanate compound is at least one selected from the group consisting of isopropylditriethanolamino titanate, titanium titanate lactate, and titanium acetylacetonate. The black resin steel sheet according to claim 1 or 2, wherein the black resin coating film has a dry coating thickness of 5 to 20 µm. The black resin steel sheet according to claim 1 or 2, wherein the black resin coating film is formed by drying the black resin composition at a peak metal temperature (PMT) of 180-260 ° C. The black resin steel sheet according to claim 2, wherein the adhesion improving coating film is formed on both sides of the base steel sheet, and the black resin coating film is formed on one surface of the adhesion improving coating film. According to claim 2, wherein the melamine-based curing agent in the polyurethane resin-melamine-based curing agent composition is at least one melamine-based selected from the group consisting of melamine, butoxymethyl melamine, hexamethoxymethyl melamine and trimethoxymethyl melamine Black resin steel sheet, characterized in that the curing agent. The silane coupling agent according to claim 2, wherein the silane coupling agent is 3-aminopropyltriepoxy silane, 3-glycidoxypropyltrimethoxy silane, 3-methoglyoxypropyltrimethoxy silane, N- (β-aminoethyl)- A black resin steel sheet, characterized in that it is at least one kind selected from the group consisting of γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltriethoxy silane, and γ-glycidoxycitrimethyldimethoxysilane. The black resin steel sheet according to claim 2, wherein the metal silicate compound is at least one selected from the group consisting of lithium polysilicate, sodium polysilicate, potassium polysilicate and colloidal silica. The black resin steel sheet according to claim 2, wherein the adhesion improving coating film is applied to the steel sheet with an adhesion amount of 800-1800 mg / m 2. The black resin steel sheet according to claim 2, wherein the adhesion improving coating has a dry coating thickness of 0.5-2 탆. The black resin steel sheet according to claim 2, wherein the adhesion improving coating film is formed by drying the adhesive resin composition with PMT of 130 to 180 ° C. At least one selected from the group consisting of polyester resins, epoxy resins, polyurethane resins and acrylic resins, 20 to 40 parts by weight of the main resin-melamine-based curing agent composition having a weight average molecular weight of 4,000 to 15,000, carbon black pigments 2 to 6 At least one kind of fingerprint selected from the group consisting of parts by weight, matting agent 2 to 6 parts by weight, titanate compound 2 to 6 parts by weight and dimethyltetramethoxy disiloxane, dodecamethylpenta siloxane, dimethyl polysiloxane and modified acrylic resin Black resin composition containing 0.5-2 weight part of additives. An adhesive resin composition comprising 5 to 15 parts by weight of a polyurethane resin-melamine-based curing agent composition, 1 to 4 parts by weight of a silane coupling agent, 1 to 4 parts by weight of a metal silicate compound, and 1 to 4 parts by weight of a titanate compound.

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