JP2015218289A - Two-liquid type polyurethane paint composition and coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-liquid type polyurethane paint composition and a coating film that have a matte effect, a smooth feeling, and a moist feeling and also have high designability.SOLUTION: A two-liquid type polyurethane paint composition according to the present invention comprises a basis comprising polycarbonate polyol with an average molecular weight of 1000-2000, a curing agent comprising polyisocyanate, silica, a surface-conditioning agent, and a catalyst.

Description

  The present invention relates to a coating film and a coating composition having a matte, moist, and smooth feel and excellent durability.

  Conventionally, polyurethane-based coating films have been used in a wide range of areas such as synthetic leather, artificial leather, adhesives, furniture paints, and automobile paints. As paints, polyether-based polyols and polyester-based polyol components that react with isocyanates. Polyol is used. In recent years, in addition to the demands for chemical resistance such as heat resistance, weather resistance, abrasion resistance and other chemical resistance such as oil resistance, hydrolysis resistance, etc., high design such as matte, smooth feeling and moist feeling Sex is also required.

  For example, in Patent Document 1, the surface of a plastic part has an elongation of 60 to 180% at 20 ° C., a friction coefficient of 0.5 to 0.8, and an initial value for the purpose of giving the plastic part a soft touch similar to leather. A method for modifying the surface of a plastic part is described, wherein a coating film having an elastic modulus of 60 to 150 kg / cm 2 is coated with a film thickness of 20 to 150 μm.

  Further, Patent Document 2 describes “a touch-sensitive paint that stably and reliably expresses a feeling of moistness, a feeling of smoothness, etc., and a good elasticity on a substrate of any kind and shape”. .

JP 2007-319836 A JP 2004-285341 A

  However, in the prior art, a polycarbonate polyol of a type in which two or more types of monomers are copolymerized is used in order to improve the performance of the polyol itself, and to achieve both smooth and moist feeling. Therefore, when an additive such as silica filler is added, there is a problem that the moist feeling is impaired. Accordingly, there has been a demand for a coating film having a good balance of matte effect, moist feeling, and smooth feeling.

  An object of the present invention is to provide a two-pack type polyurethane coating composition and a coating film having a matte effect, a smooth feeling and a moist feeling, and having a high design property.

  The two-component polyurethane coating composition according to the present invention contains a main component containing a polycarbonate polyol having an average molecular weight of 1000 to 2000, a curing agent containing polyisocyanate, silica, a surface conditioner, and a catalyst. .

  According to the present invention, it is possible to provide a two-component polyurethane coating composition and a coating film that have a moist feeling and a high tactile sensation and can realize a matting effect stably and reliably.

FIG. 1 shows the configuration of the coating layer of the present invention.

  The present invention will be described in detail below.

  The polycarbonate polyol used in the present invention is not particularly limited. For example, a polycarbonate polyol obtained by reacting an aliphatic polyol and a carbonate ester can be used. As the aliphatic polyol and carbonate ester, the following can be used. For example, ethylene glycol, 1,3-propanediol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1, Examples include aliphatic polyols such as 9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and isomers thereof. Examples of the carbonate ester include aliphatic carbonates such as dimethyl carbonate and diethyl carbonate, aromatic carbonates such as diphenyl carbonate, and cyclic carbonates such as ethylene carbonate. Polycarbonate polyols obtained by reacting these aliphatic polyols with carbonates can be used in the present invention. In order to obtain the polycarbonate polyol, the aliphatic polyol may be reacted with the carbonate ester alone or in combination. In the present invention, the polycarbonate polyols may be used alone or in combination. From the viewpoint of touch, polyhexamethylene carbonate diol is preferable.

  The polycarbonate-based polyol can contain other polyols. Examples of other polyols include high molecular weight polyols and low molecular weight polyols. The high molecular weight polyol and the low molecular weight polyol are not particularly limited. Specific examples include polyester polyols, polyether polyols, and acrylic polyols. Examples of the polyester polyol include polyethylene adipate diol, polybutylene adipate diol, polyethylene butylene adipate diol, polyhexamethylene isophthalate adipate diol, polyethylene succinate diol, polybutylene succinate diol, polyethylene sebacate diol, polybutylene sebacate Examples include diol, poly-ε-caprolactone diol, poly (3-methyl-1,5-pentylene adipate) diol, polycondensate of 1,6-hexanediol and dimer acid. Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide and propylene oxide, random copolymers and block copolymers of ethylene oxide and butylene oxide, and the like. Furthermore, a polyether polyester polyol having an ether bond and an ester bond can also be used. The low molecular weight polyol is not particularly limited, and for example, ethylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,9 -Nonanediol, 2-methyl-1,8-octanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol and the like. Furthermore, low molecular weight polyhydric alcohols such as trimethylolpropane, pentaerythritol, sorbitol and the like may be used.

  The average molecular weight of the polycarbonate polyol contained in the main agent in the present invention is preferably in the range of 1000 to 2000. By setting the molecular weight within this range, the desired physical properties such as elastic modulus and strength can be ensured. The hydroxyl value of the polycarbonate polyol is preferably in the range of 10 to 300, more preferably in the range of 40 to 100. This polycarbonate-based polyol is 40 to 90 wt% with respect to the solid content of the coating composition, and is preferably used as 50 to 80 wt%.

  The polyisocyanate used in the present invention is not particularly limited. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylene-l, 4-diisocyanate, xylene-l, 3-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4′-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4′-diisocyanate, 2,2′-diphenylpropane-4,4′-diisocyanate, 3,3′-dimethyldiphenylmethane-4,4′-diisocyanate, 4,4′-diphenylpropane diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1, Aromatic diisocyanates such as 5-diisocyanate, 3,3′-dimethoxydiphenyl-4,4′-diisocyanate, aromatic polyisocyanates such as polyphenylene polymethylene polyisocyanate, crude tolylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, deca Organic diisocyanates such as alicyclic diisocyanates such as aliphatic diisocyanates such as methylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethylxylene diisocyanate, and the aforementioned organic polyisocyanate Modified biuret, modified uretdione, Bojiimido modified products, isocyanurate modified product, uretonimine modified product, a mixture of these modified products thereof. These can be used alone or in admixture of two or more. In particular, isocyanurate-modified hexamethylene isocyanate is preferable from the viewpoint of touch.

  The silica filler in the two-component polyurethane coating composition of the present invention is used for imparting a feeling of smoothness. Specifically, a granular material having an average particle diameter of 50 μm or less, more preferably 1 to 30 μm is preferable, and an inorganic granular material having the average particle diameter is more preferable. The content of silica filler is 0.5 to 15 wt% with respect to the solid content of the two-component polyurethane coating composition, and 5 to 10 wt% is preferably used.

  The surface conditioner in the two-component polyurethane coating composition of the present invention is for imparting a moist and highly tactile feel to the coating film of the present invention. Specifically, a surface conditioner such as polyether silicone is preferable. The content of the surface conditioner is 0.5 to 2.0 wt%, preferably 1.0 to 2.0 wt%, based on the solid content of the two-component polyurethane coating composition.

  The ratio of the polycarbonate polyol to the polyisocyanate is such that the ratio of the isocyanate group of the polyisocyanate to the hydroxyl group of the polycarbonate polyol (NCO / OH) is in the range of 0.8 to 3.0, and preferably 1 to 1.5.

  When (NCO / OH) is greater than 3.0, unreacted isocyanate remains after heating. Isocyanate is a liquid, exists as a liquid even after heating, becomes a gel, and does not function as a coating film. When (NCO / OH) is smaller than 0.8, unreacted polyol remains after heating. The polyol is also a liquid and exists as a liquid after heating, and the coating film is not cured. Therefore, (NCO / OH) is preferably in the range of 0.8 to 3.0.

  A catalyst can be used for the reaction between the polycarbonate polyol of the present invention and the polyisocyanate. The catalyst is not particularly limited. For example, tin catalysts (trimethyltin laurate, dibutyltin dilaurate, etc.), lead catalysts (lead octylate, etc.), bismuth catalysts, zinc catalysts, aluminum catalysts, amine catalysts, etc. (Triethylamine, N-ethylmorpholine, triethylenediamine, diazabicycloundecene, etc.). From the viewpoint of reactivity, amine-based catalysts, tin-based catalysts, and bismuth-based catalysts are preferred. These may be used singly or as necessary. The amount of the catalyst used is 10 wt% or less, preferably 5 wt% or less, based on the solid content of the two-component polyurethane coating composition. If it is 10 wt% or more, the pot life is shortened, so workability is impaired. Moreover, when it is less than 0.01 wt% with respect to the solid content of the two-component polyurethane coating composition, the reaction promoting effect is remarkably reduced and the heat curing time is prolonged, so that workability is impaired.

  Examples of the organic solvent that can be used as a solvent in this reaction include ethyl acetate, toluene, acetone, methyl ethyl ketone, tetrahydrofuran, dimethylformamide, dioxane, dimethyl sulfoxide, and N-methyl-2-pyrrolidone. In this invention, it is preferable to use as a mixed solvent containing these two or more.

  In addition to the above-mentioned components, the coating composition may contain extender pigments, color pigments, dyes, dispersion stabilizers, viscosity modifiers, UV absorbers, antioxidants, light stabilizers, fluorescent whitening agents, fluorescent whitening agents, and extinguishing agents. You may contain additives, such as a foaming agent, a film-forming aid, and a feeling agent. The additive can be contained in both the main component containing the polycarbonate polyol and the curing agent containing the polyisocyanate, or may be contained in either one.

  There is no limitation on the base material, and any type and shape may be used. However, the surface of the base material may be smooth, or may have been subjected to graining or the like in advance. The coating film of the present invention preferably has a dry thickness of 1 to 100 μm, particularly 5 to 50 μm.

  Production examples and examples of the two-component polyurethane coating composition of the present invention will be described to explain the present invention more specifically.

[Examples 1 to 16]
In Examples 1 to 16, polycarbonate polyol (NIPPOLAN982R, manufactured by Nippon Polyurethane Co., Ltd., hydroxyl value 56.1), polyisocyanate (CORONATE HXR, manufactured by Nippon Polyurethane Co., Ltd.), isocyanate content in the blending amounts shown in Table 1. 21.6 to 22.1%), a hydrophilic leveling agent (Glide 440, manufactured by Evonik), silica filler (ACEMATT HK400, manufactured by Evonik), and an organic solvent are mixed with a disperser or a high-speed stirrer, and a coating composition is prepared. It was adjusted. The obtained coating composition was applied onto an ABS resin substrate using an air spray and dried at 80 ° C. for 30 to 120 minutes to form a coating film. The obtained coating film was subjected to an elastic modulus measurement test, a contact angle measurement test, and a friction coefficient measurement test. These measurement results are shown in Table 1.

FIG. 1 shows the configuration of the coating layer of the present invention. A colored layer 2 is formed on the substrate 1, and an overcoat layer 3 is formed on the colored layer 2. This topcoat layer 3 contains a coating composition.
(Comparative Example 1)
In Comparative Example 1, polycarbonate polyol (NIPPOLAN982R, manufactured by Nippon Polyurethane Co., Ltd., hydroxyl value 56.1), polyisocyanate (CORONATE HXR, manufactured by Nippon Polyurethane Co., Ltd.), isocyanate content 21. 6-22.1%), an organic solvent was mixed with a disperser or a high-speed stirrer to prepare a coating composition. The obtained coating composition was applied onto an ABS resin substrate using an air spray and dried at 80 ° C. for 120 minutes to form a coating film. The obtained coating film was subjected to an elastic modulus measurement test, a contact angle measurement test, and a friction coefficient measurement test. These measurement results are shown in Table 2.
(Comparative Example 2)
In Comparative Example 2, polycarbonate polyol (NIPPOLAN982R, manufactured by Nippon Polyurethane Co., Ltd., hydroxyl value 56.1), polyisocyanate (CORONATE HXR, manufactured by Nippon Polyurethane Co., Ltd.), isocyanate content 21. 6-22.1%), a hydrophilic leveling agent (Glide 440, manufactured by Evonik) and an organic solvent were mixed with a disperser or a high-speed stirrer to prepare a coating composition. The obtained coating composition was applied onto an ABS resin substrate using an air spray and dried at 80 ° C. for 120 minutes to form a coating film. The obtained coating film was subjected to an elastic modulus measurement test, a contact angle measurement test, and a friction coefficient measurement test. These measurement results are shown in Table 2.
(Comparative Examples 3-6)
In Comparative Examples 3 to 6, polycarbonate polyol (NIPPOLAN982R, manufactured by Nippon Polyurethane Co., Ltd., hydroxyl value 56.1), polyisocyanate (CORONATE HXR, manufactured by Nippon Polyurethane Co., Ltd.), isocyanate content in the blending amounts shown in Table 2. 21.6 to 22.1%), a hydrophilic leveling agent (Glide 440, manufactured by Evonik), silica filler (ACEMATT HK400, manufactured by Evonik), and an organic solvent are mixed with a disperser or a high-speed stirrer, and a coating composition is prepared. It was adjusted. The obtained coating composition was applied onto an ABS resin substrate using an air spray and dried at 80 ° C. for 120 minutes to form a coating film. The obtained coating film was subjected to an elastic modulus measurement test, a contact angle measurement test, and a friction coefficient measurement test. These measurement results are shown in Table 2.
[Elastic modulus evaluation test 1]
The coated film was cut into strips, and the elastic modulus was measured by dynamic viscoelasticity measurement (DMA) (TA200, manufactured by TA Instruments). The heating rate was 2 ° C./min, the distance between chucks was 10 mm, and the measurement frequency was 10 Hz. The storage elastic modulus from room temperature to 80 ° C. was measured, and the storage elastic modulus at room temperature was defined as the elastic modulus.
[Contact angle evaluation test 2]
With a contact angle meter (CA-S150, manufactured by Kyowa Interface Science), water and hexadecane were dropped onto the coating film with a microsyringe, and the contact angles of water and hexadecane were measured 10 seconds after the dropping. From the measurement results and the surface tension of water and hexadecane, the polar component of the surface tension was derived using the Young-Dupre equation and the Owens-Wendt equation.
[Friction coefficient evaluation test 3]
The coefficient of friction of the obtained coating was measured with a load variation type friction / wear tester (HHS-3000, manufactured by Shinto Kagaku). Using polyethylene spheres, loads of 100 g, 150 g, and 200 g were applied, and a distance of 10 mm was measured while moving the coating film at a speed of 0.2 mm / s. The static friction coefficient was measured while changing the measurement location, and the average was taken as the friction coefficient.

  As shown in Table 1, in Examples 1 to 16, the obtained coating film has a modulus of elasticity of 1 to 100 MPa, a polar component of 1 to 8 mN / m, and a friction coefficient of 0.5 to 1.5. A high-tactile coating film having a moist and smooth feeling was obtained.

  The moist feeling contributes to the elastic modulus and the polar component, and the smooth feeling contributes to the friction coefficient and the surface roughness. Also, the matte effect is due to the silica filler. Silica filler increases the surface roughness, causes light scattering, and provides a matte effect.

  In Examples 1 to 3, NCO / OH was fixed at 1, the addition amount of the hydrophilic leveling agent was fixed at 0.5 wt%, and the addition amount of silica filler was varied. When the addition amount of silica filler is increased from 0.5 wt% to 9 wt%, the friction coefficient increases from 0.5 to 1, and the polar component decreases from 2.5 mN / m to 1 mN / m. A highly tactile coating film having a feeling was obtained.

  In Examples 4 to 6, NCO / OH was fixed at 1, the addition amount of the hydrophilic leveling agent was fixed at 2 wt%, and the addition amount of silica filler was varied. When the addition amount of silica filler is increased from 6 wt% to 15 wt%, the friction coefficient increases from 1 to 1.3 and the polar component decreases from 2.7 mN / m to 1.1 mN / m. A highly tactile coating film having a feeling was obtained.

  In Examples 7 to 9, NCO / OH was set to 1.3, the amount of hydrophilic leveling agent added was fixed at 2 wt%, and the amount of silica filler added was varied. When the addition amount of silica filler is increased from 6 wt% to 15 wt%, the friction coefficient increases from 0.9 to 1.3 and the polar component decreases from 2.6 to 1, but it has a moist and smooth feeling. A tactile paint film was obtained.

  In Example 10, 1.3 NCO / OH, 6 wt% silica filler, and 0.5 wt% leveling agent were added. Compared with Example 2 where the addition amount of silica filler and leveling agent is the same and NCO / OH is 1, the polar component of the coating film is reduced by 0.3 mN / m and the coefficient of friction remains unchanged at 0.9. A paint film having a high tactile sensation was obtained.

  In Examples 11 and 12, NCO / OH was fixed at 2, the addition amount of the hydrophilic leveling agent was fixed at 2 wt%, and the addition amount of silica filler was varied. When the amount of silica filler added is increased from 6 wt% to 9 wt%, the friction coefficient increases from 0.6 to 0.8 and the polar component decreases from 1.4 to 1.2. A highly tactile paint film having the above was obtained.

  In Examples 13 and 14, a tin-based catalyst was used. NCO / OH was fixed at 1, the addition amount of the hydrophilic leveling agent was fixed at 2 wt%, and the addition amount of silica filler was varied. When the amount of silica filler added is increased from 6 wt% to 9 wt%, the friction coefficient increases from 0.7 to 0.8 and the polar component decreases from 2.8 mN / m to 1.8 mN / m. As a result, a highly tactile coating film having a smooth feeling was obtained.

  In Examples 15 and 16, a bismuth-based catalyst was used. NCO / OH was fixed at 1, the addition amount of the hydrophilic leveling agent was fixed at 2 wt%, and the addition amount of silica filler was varied. When the amount of silica filler added is increased from 6 wt% to 9 wt%, the friction coefficient increases from 0.5 to 0.7 and the polar component decreases from 2.8 mN / m to 1.7 mN / m. As a result, a highly tactile coating film having a smooth feeling was obtained.

  On the other hand, as shown in Table 2, in Comparative Example 1, the coating composition was prepared without adding the silica filler and the hydrophilic leveling agent to form a coating film. The coefficient of friction of the coating film was 0.3, the feeling of smoothness was insufficient, and a high touch feeling was not obtained. In Comparative Example 2, 0.5 wt% of a hydrophilic leveling agent was added to prepare a coating composition. The coefficient of friction of the obtained coating film was 0.3, and the feeling of smoothness was insufficient, and a high touch feeling was not obtained. In Comparative Examples 3 to 6, the coating composition was prepared with the addition amount of silica filler being 15 or 20 wt%. The polar component of the obtained coating film was less than 1 mN / m, and the moist feeling was insufficient, and a high touch feeling was not obtained.

  DESCRIPTION OF SYMBOLS 1 ... Base material, 2 ... Colored layer, 3 ... Topcoat layer

Claims (11)

A main agent containing a polycarbonate-based polyol having an average molecular weight of 1000 to 2000;
A curing agent containing a polyisocyanate;
Silica,
A surface conditioner,
A two-component polyurethane coating composition comprising a catalyst. The two-component polyurethane coating composition according to claim 1,
The two-component polyurethane coating composition is characterized in that the content of the silica is 0.5 to 15 wt% with respect to the solid content of the two-component polyurethane coating composition. A two-component polyurethane coating composition according to claim 1 or 2,
The two-pack type polyurethane coating composition, wherein the silica has an average particle size of 50 μm or less. A two-component polyurethane coating composition according to any one of claims 1 to 3,
The surface conditioner is polyether silicone;
The two-component polyurethane coating composition is characterized in that the content of the surface conditioner is 0.5 to 2.0 wt% with respect to the solid content of the two-component polyurethane coating composition. A two-component polyurethane coating composition according to any one of claims 1 to 4,
A two-component polyurethane coating composition having a ratio (NCO / OH) of hydroxyl group (OH) of the polycarbonate polyol to isocyanate group (NCO) of the polyisocyanate of 0.8 to 3.0. A two-component polyurethane coating composition according to any one of claims 1 to 5,
The two-component polyurethane coating composition, wherein the catalyst includes any one of an amine catalyst, a tin catalyst, a bismuth catalyst, a lead catalyst, a zinc catalyst, and an aluminum catalyst. A two-component polyurethane coating composition according to any one of claims 1 to 6,
The two-component polyurethane coating composition is characterized in that the content of the catalyst is 0.01 to 10 wt% with respect to the solid content of the two-component polyurethane coating composition. The two-component polyurethane coating composition according to any one of claims 1 to 7, wherein the two-component polyurethane coating composition has an elastic modulus of 1 to 100 MPa. The two-component polyurethane coating composition according to any one of claims 1 to 8, wherein the polar component of surface tension is 1 to 8 mN / m. The two-component polyurethane coating composition according to any one of claims 1 to 9, wherein the two-component polyurethane coating composition has a friction coefficient of 0.5 to 1.5. A substrate;
A colored layer formed on the substrate;
Having an overcoat layer formed on the colored layer;
The said top coat layer contains the 2 liquid type polyurethane coating composition in any one of Claims 1 thru | or 10, The coating film characterized by the above-mentioned.