KR101374941B1 - Coating composition for interior panel of automobile - Google Patents

Abstract

25 to 50% by weight of the water-soluble hydroxyl polyester-polyurethane dispersion based on the total coating composition; 10-30% by weight of polyurethane dispersion; 4-8% by weight of water-dispersible polyisocyanate; 1 to 8% by weight of silica having a particle diameter of 5 to 10 microns; 0.1 to 5% by weight of a component selected from the group consisting of vinyl ethoxysilane, vinyl methoxy silane, methyl diethoxy silane, gamma methacryloxypropyl triethoxysilane and gamma methacryloxypropyl trimethoxysilane; 20-30% by weight of ion-exchanged water; 0.1 to 0.5% by weight of amines which are basic curing catalysts; 0.1-1% by weight of nonionic hydrophobic surfactant; And 0.1 to 1 wt% of a surface lubricant.

Automotive, interior materials, paints, amines

Description

Coating composition for automotive interiors {COATING COMPOSITION FOR INTERIOR PANEL OF AUTOMOBILE}

The present invention relates to a coating composition for automotive interiors. More particularly, the present invention relates to a paint composition for automobile interiors that can realize a high value added of a plastic material by realizing a texture felt in natural leather with a water-soluble paint to give a warm and soft texture when the body is in contact with the coating film.

Plastics used for automobile interior materials have a weak surface due to chemicals, erosion, ultraviolet rays, heat deformation, etc., and have surface defects resulting from defects in surface injection, surface defects, and color restrictions. In order to solve these problems, conventionally, water-soluble paints are applied to compensate for defects of plastic materials.

In particular, a technology for realizing the feel of natural leather in a water-soluble paint to feel a warm and soft texture when in contact with the coating film has been developed for automobile interiors.

However, in the conventional water-soluble textured paints as described above, acrylic polymers or polyurethane polymers added for viscosity behavior and rheological control remain in the dry coating film, causing deterioration of the overall physical properties of the coating film such as adhesion, scratch resistance, and abrasion resistance. In particular, it is known to weaken the wear resistance of the coating material.

The present invention solves the conventional problems as described above, by realizing the feel of natural leather in a water-soluble paint to feel a warm and soft texture when in contact with the coating film, while the overall physical properties of the coating film such as adhesion, scratch resistance, wear resistance An object of this invention is to provide a coating composition for automotive interiors.

25 to 50% by weight of the water-soluble hydroxyl polyester-polyurethane dispersion based on the total coating composition; 10-30% by weight of polyurethane dispersion; 4-8% by weight of water-dispersible polyisocyanate; 1 to 8% by weight of silica having a particle diameter of 5 to 10 microns; 0.1 to 5% by weight of a component selected from the group consisting of vinyl ethoxysilane, vinyl methoxy silane, methyl diethoxy silane, gamma methacryloxypropyl triethoxysilane and gamma methacryloxypropyl trimethoxysilane; 20-30% by weight of ion-exchanged water; 0.1 to 0.5% by weight of amines which are basic curing catalysts; 0.1-1% by weight of nonionic hydrophobic surfactant; And 0.1 to 1 wt% of a surface lubricant.

The polyester-polyurethane dispersion having a water-soluble hydroxy group used in the present invention preferably has a number average molecular weight of 5,000 to 30,000 and an elongation of 400 to 800%. When the elongation of the resin is lower than the above range, the characteristics of the texture paint are lost, and when the elongation of the resin is high, viscous properties remain on the coating film, whereby physical properties such as stain resistance, scratch resistance, and wear resistance may decrease. In addition, the hydroxyl content of 1 to 3% by weight was used that can control the viscosity behavior only by pH.

The hydroxyl polyester-polyurethane dispersion resin is used in 25 to 50% by weight in terms of solids relative to the total coating composition, when the amount is less than 25% by weight, physical properties such as adhesion, hardness of the coating film is lowered When it exceeds 50% by weight, the soft texture is inferior.

Polyurethane dispersion used in the present invention is a polyether, polyester or polycarbonate-based number average molecular weight of 10,000 to 100,000, elongation of 500 to 1,000%, hydroxyl content of 1 to 3% by weight, tensile strength of 3,000 More preferably, 6,000 psi and a particle size of 50-300 nm. If the elongation of the resin is less than 500%, the soft touch, which is a characteristic of the texture paint, is lost. If the elongation exceeds 1,000%, the viscosity remains on the coating film, and thus physical properties such as stain resistance, scratch resistance, and wear resistance may be reduced.

The amount of the polyurethane dispersion is 10 to 30% by weight in terms of solids with respect to the total coating composition, less than 10% by weight of the coating film is less effective, when it exceeds 30% by weight of the coating film properties.

The composition of the present invention requires mechanical properties and chemical resistance such as wear resistance, scratch resistance, light resistance, chemical resistance, etc. while maintaining a soft coating film for use, and thus maintains a flexible and elastic coating film. There is a need for a technique for imparting density. Therefore, while a coating composition using a polyurethane resin is weak in physical properties such as hardness of the coating film, the coating composition using a mixed resin of the hydroxyl polyester-polyurethane dispersion and the polyurethane dispersion of the present invention is crosslinked with a curing agent. The hardness of the coating film is excellent due to the flexibility of the after coating film and the film density.

The ratio of resin use ratio of the water-soluble hydroxyl polyester-polyurethane dispersion and the polyurethane dispersant is in the ratio of 1: 1 to 2.5: 1 based on solid content, and when the amount of the hydroxyl polyester-polyurethane dispersion is used is large, The coating properties are excellent, but the texture is lowered, there is a problem that the chemical resistance is lowered if less.

On the other hand, in order to form a coating film of the water-soluble hydroxyl resin, a curing agent capable of bonding with a hydroxyl group is required. As a hardening | curing agent of the modified polyether type which is easy to disperse water as mentioned above, in this invention, 4-8 weight% of water dispersible polyisocyanate, for example, hexamethylene diisocyanate, is used.

The combination of isocyanate and hydroxyl polyester-polyurethane dispersion forms a rigid polyurethane coating, and in addition, the isocyanate group and water react to form a polyurea. As a result, the structure of the polyurethane film through the reaction has a form in which the polyurethane and the polyurea are entangled in a mesh with each other.

In addition to polyisocyanate-based curing agents, crosslinking can be formed using aziridine or carbodiimide-based curing agents, but its structure is poor compared to isocyanate-hydroxyl crosslinking density, which is insufficient in physical properties such as sensitivity, light resistance, and chemical resistance. It shows physical properties.

Since the crosslinking of the water-soluble polyurethane resin is accompanied by an addition reaction, the reaction ratio (NCO / OH) of isocyanate and hydroxyl groups should be used in the range of 1.3 to 1.8, and if it is small, the coating film properties such as wear resistance and chemical resistance will be reduced. At high temperatures, the coating becomes hard and loses its texture.

On the other hand, since the coating composition of the present invention is a textured coating used for indoor use, a low gloss of 2o or less is required on the basis of glossometer 60o gloss.

The degree of gloss is affected by factors such as surface roughness, solvent evaporation and film shrinkage, coating process, temperature and humidity conditions, composition of solvent and additive, and is primarily determined by the roughness of the coating film surface.

In order to show the effect of surface roughness, materials generally used in paints include silica, talc, calcium carbonate, etc. After the paint is coated on the substrate, the matting agent is uniformly distributed in the wet coating film. As the solvent or water evaporates, the thickness of the coating film decreases, and as the film shrinks, a rough surface of the matting agent appears. At this time, irradiated light diffuses and scatters on the rough surface, so that the high and low gloss can be recognized. do.

In general, the gloss decreases as the amount of the matting agent is increased, and as the particles of silica become rough, a low gloss coating film is formed.

Silica, a component for reducing the glossiness of a coating film, can be generally classified into heat treatment, sinking type, organic coating, fumed, wax coated silica, etc. according to the manufacturing method, and physical properties such as transparency, matting efficiency and scratch resistance of the dry coating film. In order to secure it is advantageous to use a silica prepared by a heat treatment method excellent in hardness characteristics. Surface texture can be improved when using waxed silica.

The porous properties of silica show a high quenching effect, but when used in a large amount, it can absorb the resin powder and cause a decrease in the softness of the coating or the coating film. Since the amorphous film is formed irregularly on the surface, it is weak to scratches.

In the present invention, 1 to 8% by weight of silica having a particle diameter of 5 to 10 microns which is excellent in scratch resistance and does not affect the stiffness, in particular, micronitized silica is preferably used. If the amount is less than 1% by weight, the scratch resistance is lowered. If it is more than 8% by weight, the selectivity is lowered.

The component selected from the group consisting of vinylethoxysilane, vinylmethoxysilane, methyldiethoxysilane, gamma methacryloxypropyltriethoxysilane, and gamma methacryloxypropyltrimethoxysilane induces a bond with silica. It has the function of improving chemical and solution stability. Preferably, methyldiethoxy silane having effective physical properties such as adhesion and storage stability among the above components may be used.

In the present invention, vinylethoxysilane, vinylmethoxysilane, methyldiethoxysilane, gamma methacryloxypropyltriethoxysilane, and gamma methacryloxypropyltrimemium to improve the wear resistance of the coating due to the texture characteristics 0.1 to 5% by weight of a component selected from the group consisting of oxysilane is used. If the amount of the component is less than 0.1% by weight, there is little effect of improving the physical properties, and when the amount is more than 5% by weight, poor paint storage property may be caused.

In the coating composition of the present invention, ion exchange water is used in an amount of 20 to 30% by weight, and when the amount thereof is less than 20% by weight, the viscosity of the paint is high and workability is lowered. .

Conventional water-soluble paints used acrylic polymers or polyurethane-based polymers for viscosity behavior and rheology control, but such components remain in the dry coating film, causing deterioration of the overall physical properties of the coating film, such as abrasion resistance and moisture resistance. There was a problem of vulnerable wear resistance.

Therefore, in the present invention, since the viscosity behavior and the rheology control are performed using amines which are basic curing catalysts without using such thickeners, the problems as mentioned above are not caused.

As the amines which are the basic curing catalysts, one or two or more selected from triethanol amine, dimethylethanolamine, 2- (ethylamino) ethanol and diazabicycloundecene may be used, and in particular, dimethylethanolamine (DMEA). Is most preferred.

In the present invention, the basic curing catalyst amines are preferably used in 0.1 ~ 0.5% by weight, when included in less than 0.1% by weight is significantly slower curing time, when exceeding 0.5% by weight is poor in pot life problems workability It is a factor which reduces the hardness and adhesiveness of a coating film.

In addition, in the present invention, the amines, which are basic curing catalysts, have a breaking point of 130 ° C. or more, and act as plasticizers at room temperature to further reinforce the flexibility of the coating film and help to express a beautiful appearance.

In the present invention, non-ionic hydrophobic surfactants such as siloxane-based, sulfone-based, and ethoxy-modified polyether-based surfactants may be used for surface wetting of plastic materials, and preferably, antifoaming and dynamic surface tension lowering effects. 0.1-1 weight% of the acetyl renic diol type surfactant which is excellent in it is used.

Surface lubricants used in the present invention include dimethylpolysiloxane or methylphenylpolysiloxane, methylhydrogenpolysiloxane or modified substances thereof, for example epoxy or alkyl, amino or carboxyl, alcohol or fluorine, Modified products, such as an alkyl aralkyl polyether system, an epoxy polyether system, and a polyether system, etc. are mentioned. In particular, it is preferable to use the dimethylpolysiloxane type surface lubricant in an amount of 0.1 to 1% by weight based on the total coating composition.

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In addition, in the coating composition of the present invention, water and the like may be used as necessary for adjusting the pigments, additives and paint viscosity known in the art. Pigments include inorganic or organic coloring pigments, and additives include dispersants, neutralizers, antifoaming agents, and the like.

The paint composition of the present invention exhibits very good sensitization quality (texture) as compared to conventional aqueous paints when used in automotive interior materials, and exhibits excellent properties in physical properties such as adhesion, scratch resistance and abrasion resistance. .

In particular, it can be usefully used for the application of TPU (Thermoplastic Urethane) material for automobile interior.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples. However, the scope of the present invention is not limited to the following examples.

Example 1, Comparative Examples 1 and 2: Preparation of paint composition for automotive interior

A coating composition for automobile interior was prepared by the method described below with the composition components and contents shown in Table 1 below.

A B C D E F G H I J K L Example 1 40 20 6 5 One 26 0.3 0.1 0.1 0.5 One Comparative Example 1 40 20 6 5 One 25.3 One 0.1 0.1 0.5 One Comparative Example 2 40 20 6 5 One 25.3 One 0.1 0.1 0.5 One

Composition ratio unit: weight%

A) A hydroxyl polyester-polyurethane dispersion having a number average molecular weight of 5,000 to 30,000 and an elongation of 400 to 800% as an aliphatic polyester system (manufacturer: Bayer, trade name: PR240)

B) A water-soluble polyurethane resin having a polyether-based number average molecular weight of 10,000 to 100,000, particles of 50 to 300 nm, elongation of 500 to 1000%, and tensile strength of 3000 to 6000 PSI (manufacturer: Bayer, trade name: XP2428).

C) Water-dispersible polyisocyanate (HDI TRIMER)

D) Micronized Silica with a particle size of 5-10 microns

E) Methyldiethoxy Silane

F) ion exchange water

G) Dimethylethanolamine

H) polyurethane thickener

I) Dimethyl Polysiloxane Surface Lubricant

J) Acetylene Diol Nonionic Surfactant

K) UV stabilizer

L) Pigment (Black)

[Manufacturing method]

The hydroxyl polyester-polyurethane dispersion (A) and the water-soluble polyurethane resin (B) are placed in a container and mixed at low speed using a stirrer. Micronized silica (D) was added during stirring, and dispersed at 1000 rpm for 10 minutes. Methyl diethoxysilane (E), an acetylenic diol nonionic surfactant (J), a dimethylpolysiloxane-based surface lubricant (I), a UV stabilizer (K), and a pigment (L) were added and stirred at 1000 rpm for 10 minutes. Dimethylethylamine (G) (or Polyurethane and (H)) Moisture-adhesive and water-dispersible polyisocyanate (C) with ion-exchanged water (F) adjusted to Pod Cup NO # 4 35-40 seconds (C) Of the curing agent).

Test example.

Using the respective compositions, the TPU (Thermoplastic Urethane) specimens were spray-coated with a dry coating thickness of 30 microns, and then dried for 20 minutes at a temperature of 80 ° C., and then left for 24 hours to evaluate physical properties.

Physical properties of the coating film prepared as described above are shown in Table 2, and the results are shown in Table 3 below.

Item standard Test Methods Quality Emotional Evaluation Using Designer's Hand Exterior Over coating × Visual evaluation Soak 3% less than Calculate the degree of permeability of the glass lid filled with volatiles from the specimen in a glass container and heated at 100 ℃ for 5 hours. Adhesion M-2.5 ↓ In accordance with JIS D0202, draw parallel lines at intervals of 2 mm, attach and detach the cellophane tape, and determine the state of the coating film. smell Not disgusting (Level 3) The specimens were cut to 5x6 cm, placed in a 4 liter desiccator and aged at 100 ° C. for 2 hours before evaluation by three or more panels smelling. Moisture resistance Attachment M-2.5 ↓
Color difference ΔE≤2
Gloss change ± 0.3 Specimen observed after 168 hours at 50 ° C and 98% relative humidity Heat aging resistance Attachment M-2.5 ↓
Color difference ΔE≤2
Gloss change ± 0.3 Specimen observation after standing at 90 ℃ for 300 hours Photo-aging property Attachment M-2.5 ↓
Color difference ΔE≤2
Gloss change ± 0.3 Specimens were observed after exposure to 1050 kJ / m2 of light with a Xenon Arc Light Resistance Tester. Scratch resistance Surface Damage × Surface observation by scratching at 100mm / sec speed with 0.5R sapphire needle Non-stickiness Level 4 or above After putting two coated specimens together and leaving them at 80 ℃ oven for 2 hours under 500g load, observe whether they stick together. Film fouling resistance Over coating × Put paint and urethane material in desiccator and heat it at 80 ℃ for 22 hours to observe whether the coating film is contaminated Chemical resistance Over coating × Observe color transitions in glass cleaners, neutral detergents, IPAs, and polished waxes Wear resistance Possession impression × 500 round trips at 300 mm / sec to check for wear

Item standard Example 1 Comparative Example 1 Comparative Example 2 Quality - Leather texture Leather texture Rubber texture Exterior - Good Good Good Soak 3 or less 2 3 3 Adhesion M-2.5 ↓ M-1 M-1 M-5 smell Level 3 or higher 3.5 grade Level 3 Level 3 Moisture resistance Defect x Color difference 2.18 3.12 3.36 Polish 1.5 → 1.5 1.5 → 1.6 1.5 → 1.2 Heat aging resistance Defect x Color difference 0.40 1.52 1.8 Polish 1.5 → 1.5 1.5 → 1.6 1.5 → 1.7 Photo-aging property Defect x Color difference 0.40 0.44 0.47 Polish 1.5 → 1.5 1.5 → 1.3 1.5 → 1.3 Scratch resistance No surface damage 4th grade Level 3 2nd class Non-stickiness Level 4 or above clear clear clear Paint fouling Film Elution x clear clear clear Chemical resistance ABRAISON clear clear clear DROP clear clear clear Abrasion resistance Possession x Very good Possession exposure Sozinnotz

The paint composition for automobile interior of the present invention realizes the texture felt in natural leather as a water-soluble paint, so that the overall physical properties of the coating film are excellent while allowing a warm and soft texture to be felt when the body is in contact with the coating film. Shows excellent physical properties.

Claims (8)

25-50% by weight of water-soluble hydroxyl polyester-polyurethane dispersion based on the total coating composition; 10-30% by weight of polyurethane dispersion; 4-8% by weight of water-dispersible polyisocyanate; 1 to 8% by weight of silica having a particle diameter of 5 to 10 microns; 0.1 to 5% by weight of a component selected from the group consisting of vinyl ethoxysilane, vinyl methoxy silane, methyl diethoxy silane, gamma methacryloxypropyl triethoxysilane and gamma methacryloxypropyl trimethoxysilane; 20-30% by weight of ion-exchanged water; 0.1 to 0.5% by weight of amines which are basic curing catalysts; 0.1-1% by weight of nonionic hydrophobic surfactant; And 0.1 to 1% by weight of a surface lubricant. The coating composition for automobile interiors according to claim 1, wherein the water-soluble hydroxyl polyester-polyurethane dispersion has a number average molecular weight of 5,000 to 30,000 and an elongation of 400 to 800%. The method of claim 1, wherein the polyurethane dispersion is a polyether-based vehicle having a number average molecular weight of 10,000 to 100,000, elongation of 500 to 1,000%, tensile strength of 3,000 to 6,000 psi, particle size of 50 to 300nm. Paint composition. The coating composition for automobile interiors according to claim 1, wherein the water dispersible polyisocyanate is hexamethylene diisocyanate. The coating composition of claim 1, wherein the weight ratio of the water-soluble hydroxyl polyester-polyurethane disper before and the polyurethane disper is 1: 1 to 2.5: 1 based on solids. The coating composition for automobile interiors according to claim 1, wherein the silica having a particle size of 5 to 10 microns is micronized silica. The component selected from the group consisting of said vinyl ethoxysilane, vinyl methoxysilane, methyl diethoxysilane, gamma methacryloxypropyl triethoxysilane, and gamma methacryloxypropyl trimethoxysilane A paint composition for automobile interiors, characterized in that it is oxysilane. The method of claim 1, wherein the amines of the basic curing catalyst is one or two or more selected from triethanol amine, dimethylethanolamine, 2- (ethylamino) ethanol, and diazabicyclodecene. Paint composition.