JP5101892B2 - Colored paint composition and colored coating film - Google Patents

Description

The present invention relates to a colored coating composition and a colored coating film.

In general, a plurality of colored pigments are used in paints to adjust the hue. This colored pigment can be adsorbed to the resin by acid-base interaction or hydrophobic interaction and can be stably present in the paint (for example, see Non-Patent Document 1).
If the paint film is formed by partially repainting it for the purpose of repair before drying the paint film obtained by applying this paint once, it is obtained by applying it once called color separation. There was a problem that a color difference occurred between the coated film and a coating film formed by partially repainting. Such color separation generally occurs when the dispersion stability is lowered due to insufficient adsorption of the resin to the pigment when the pigment is dispersed in the paint, and there are a plurality of colored pigments. In some cases, it is considered to be more prominent due to the interaction between the pigments.

By the way, in many paints, yellow iron oxide is used as a coloring pigment. This yellow iron oxide is generally needle-shaped. However, the coating film obtained by using this paint containing acicular yellow iron oxide differs from the surroundings only in the part applied in a direction different from the other part depending on the incident angle of light and the position seen by humans. Sometimes it looked like a painted color. In order to solve such a problem, a colored coating composition using a yellow iron oxide pigment having a small long side length / short side length ratio is known (for example, see Patent Document 1). However, there is no suggestion about color separation in this document.

JP 2006-8935 A Nihon Paint "Easy Technical Review: Characters and Functions of Paints" Nippon Paint Newspaper, April 16, 1998, p. 462-463

An object of the present invention is to provide a colored coating composition in which the color does not change depending on the viewing position and the color separation does not occur.

The present invention is a colored coating composition containing yellow iron oxide, wherein at least part of the yellow iron oxide has a stearic acid adsorption amount of 35 to 100 μmol / g, and a long side length / short side length. Is a special yellow iron oxide having a ratio of 1 to 3, and further contains a coloring pigment other than yellow iron oxide and a binder resin.

It is preferable that the content rate of the said special yellow iron oxide is 50 mass% or more in all the yellow iron oxides contained in a coloring coating composition.
The colored coating composition preferably has a total color pigment volume concentration of 20% or less.
The colored coating composition is preferably an organic solvent-type coating.

This invention is also a colored coating film characterized by being obtained with the said colored coating composition.
The present invention is described in detail below.

The present invention includes yellow iron oxide as a color pigment, and at least part of the yellow iron oxide has a stearic acid adsorption amount of 35 to 100 μmol / g, and a ratio of long side length / short side length is It is a coloring coating composition which is the special yellow iron oxide which is 1-3. Since special yellow iron oxide having a predetermined long side length / short side length ratio and a predetermined stearic acid adsorption amount is included, various resins are sufficiently adsorbed to the pigment, thereby As a result, it is possible to obtain a coating film in which color separation does not occur due to repainting. That is, the effect of the present invention can be obtained by making the shape of the special yellow iron oxide and the stearic acid adsorption amount specific.

The special yellow iron oxide has a stearic acid adsorption amount of 35 to 100 μmol / g. Color separation occurs when the adsorption amount is less than 35 μmol / g. The upper limit is substantially 100 μmol / g. The adsorption amount is preferably 40 to 95 μmol / g. The adsorption amount can be typically measured by the following method.
In addition, it can measure similarly about yellow iron oxides other than the said special yellow iron oxide.

<Measurement method of stearic acid adsorption amount>
50 mL screw containing 6 g of yellow iron oxide pigment to be measured and 14 g of 2-butanone-toluene-cyclohexanone mixed solution (2-butanone: toluene: cyclohexanone = 2: 2: 1, mass ratio) containing 2% by mass of stearic acid In addition to a tube bottle (inner diameter 30 mmφ, height 77 mm), the screw tube bottle is sealed and shaken at 20 ° C. for 24 hours with a shaker. Next, solid-liquid separation is performed with a centrifuge (“Table Top Centrifuge 5420” (trade name) manufactured by Kubota Corporation), and the stearic acid concentration in the supernatant is measured using a GPC (gel permeation chromatography) analyzer. To do. The height of the peak is obtained from the obtained RI (refractive index) curve, and the stearic acid adsorption amount per unit mass of the sample is calculated from the following equation.
Stearic acid adsorption (μmol / g)
= 10 ⁶ × {(A × B / MW) / 100} × (1-SR ₁ / SR ₀ ) / C
Where A: Amount of stearic acid solution (g)
B: Stearic acid solution concentration (mass%)
MW: Stearic acid molecular weight (284)
C: Yellow iron oxide pigment collection amount (g)
SR ₀ : Peak height (cm) indicated by the RI curve of 2% by weight stearic acid solution
SR ₁ : Peak height (cm) of the RI curve of stearic acid in the supernatant

In the present invention, the special yellow iron oxide has a stearic acid adsorption amount in the above range. The amount of stearic acid adsorbed by such special yellow iron oxide can be adjusted, for example, by controlling the temperature or pH when producing yellow iron oxide.

The special yellow iron oxide has a ratio of long side length / short side length of 1 to 3. When the ratio exceeds 3, color separation occurs. The ratio is preferably 1-2. In the present invention, the ratio of the long side length / short side length of the special yellow iron oxide is a value measured in a form actually present in the colored coating composition. It does not specifically limit as said form, For example, a primary particle, a secondary particle, these aggregates, etc. can be mentioned. Therefore, since the long side length and the short side length of each primary particle are not directly measured, the ratio of the long side length / short side length of the special yellow iron oxide in the present invention is described in the catalog or the like. It may be different from the value of the particle state.

The long side length and short side length of yellow iron oxide can be typically measured by the following predetermined method.
<Measurement method of ratio of long side length / short side length>
Preparation of a coating composition for measurement having only one kind of yellow iron oxide as a color pigment, and the yellow iron oxide present in the obtained coating composition for measurement is projected onto the xy plane and processed into a rectangular shape. The longest length of the line passing through the central point of the iron oxide aggregate is defined as the long side length, and the length of the line passing through the central point is defined as the short side length of the straight line that intersects the long side at a right angle. . Specifically, using a transmission electron microscope ("JEM-200CX" (trade name) manufactured by JEOL), the center of the projected image of each aggregate in an electron micrograph at a magnification of 50,000 or 100,000. The longest line passing through the point is taken as the long side and the length is taken as the long side length. The average long side length and the average short side length were calculated. The average (long side length / short side length) was obtained by calculating the long side length / short side length for each aggregate and calculating the average value.

In addition, the specific surface area of the special yellow iron oxide in the present invention is preferably 5 to 30 m ² / g because it has a clear color tone. Examples of commercially available special yellow iron oxide used in the present invention include YM1100 (stearic acid adsorption amount 63 μmol / g, long side length / short side length ratio 2, specific surface area 17 m ² / g, titanium (Made by an industrial company) etc. can be mentioned.

Moreover, not only the case where special yellow iron oxide having the above-mentioned stearic acid adsorption amount and the ratio of long side length / short side length is used as a raw material, but also yellow iron oxide deviating from the above adsorption amount or the above ratio is used as a raw material. However, in the colored coating composition obtained as a result of being pulverized or deformed in the coating production process, the above-mentioned special yellow iron oxide may be obtained, and such yellow iron oxide is also used in the present invention. It is contained in special yellow iron oxide.

The colored coating composition of the present invention contains yellow iron oxide, and at least a part thereof is the special yellow iron oxide. In the all yellow iron oxide contained in the colored coating composition of the present invention, the content of special yellow iron oxide is preferably 50% by mass or more. When the said content rate is less than 50 mass%, there exists a possibility that the effect of this invention cannot be exhibited. The content is more preferably 70% by mass or more.

Other yellow iron oxides other than the special yellow iron oxide are not particularly limited. Specifically, Bayferrox 915 (stearic acid adsorption amount 26 μmol / g, long side length / short side length ratio 2, LANXESS), Examples include TSY-1 (stearic acid adsorption amount 67 μmol / g, long side length / short side length ratio 7, manufactured by Toda Pigment).

The colored coating composition of the present invention contains the above-mentioned special yellow iron oxide and other colored pigments other than the above yellow iron oxide. Examples of the other color pigments include ordinary color pigments used in paints, specifically, inorganic color pigments such as carbon black, titanium dioxide, and bengara, and copper phthalocyanine-based organic color pigments. .

The colored coating composition of the present invention preferably has a total color pigment volume concentration of 20% or less. If the concentration exceeds 20%, the coating performance such as water resistance and weather resistance may be deteriorated.

The colored coating composition of the present invention further contains a resin. As said resin, what acts as a binder component is preferable, For example, the well-known coating material used for coating materials, such as an acrylic resin, a polyester resin, an alkyd resin, a polyurethane resin, an epoxy resin, can be mentioned. The resin may have a curable functional group.

Furthermore, the colored coating composition may contain a curing agent. The curing agent is not particularly limited, and examples thereof include a curing functional group having a reactive functional group and a curable functional group, and specifically, when the resin has a hydroxyl group. An amino resin, a (blocked) polyisocyanate compound, etc., and if the resin has a carboxylic acid group, a resin having an epoxy group or a compound having a carbodiimide group, etc., and the resin has a carbonyl group. In the case of hydrazide, hydrazide compounds and the like can be mentioned.

The colored coating composition of the present invention preferably further contains a pigment dispersant. The colored pigment is dispersed in a pigment dispersant, stabilized, and present in the paint. It does not specifically limit as said pigment dispersant, It is preferable to select suitably the pigment dispersant matched with the form of the coloring coating composition to apply. Examples of the pigment dispersant include commonly used pigment dispersion resins. For example, commercially available pigment dispersion resins may be used.

The colored coating composition of the present invention may contain various additives well known by those skilled in the art, such as antifoaming agents, thickeners, preservatives, ultraviolet absorbers and light stabilizers, in addition to the above components. . In addition, when the coating composition of the present invention is an aqueous type, it can further contain an antifreezing agent, a film-forming aid and the like.

The form of the colored coating composition of the present invention is not particularly limited, and examples thereof include an organic solvent type and an aqueous type, and the organic solvent type is more likely to cause the color separation phenomenon described in the present invention. For many reasons, the effect of the present invention is greatest in the case of the organic solvent type.

The colored coating composition of the present invention is prepared, for example, after preparing a pigment dispersion composition comprising the colored pigment and the pigment dispersant, and then mixing and stirring the various additives as necessary. It can be obtained by mixing and stirring the resin as the binder component. The apparatus for stirring and mixing is not particularly limited, and examples thereof include a disper, a ball mill, a roll mill, a sand mill, and a homomixer, each alone or in combination.

The colored coating film obtained by the colored coating composition of the present invention is also one aspect of the present invention. The colored coating film can be obtained, for example, by a method of applying the colored coating composition to a substrate. The base material is not particularly limited, and is a metal base material such as iron, stainless steel, aluminum and the like, a cement base material such as cement, lime, gypsum, polyvinyl chloride, polyester, polycarbonate. And plastic base materials such as acrylics. An undercoat such as a sealer may be formed on these.

Moreover, it does not specifically limit as said application | coating method, For example, brush painting, roller coating, etc. can be mentioned. In addition, before drying the coating film obtained by the previous coating, there is no particular limitation as to the method of coating in the case of partial re-coating for the purpose of repair, and examples include brush coating and roller coating. it can.

After coating, the colored coating film of the present invention can be obtained by allowing it to stand at room temperature or forcibly heating and drying. The coating amount, coating film thickness, and drying time can be arbitrarily set according to the type of coating material and the substrate to be applied.

According to the present invention, a colored coating composition in which color separation does not occur can be obtained.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Production Example 1 Preparation of Acrylic Resin 382.5 g of Cactus Solvent P-20 was charged into a 1 L glass vessel, subjected to nitrogen bubbling, and heated to 110 ° C. with stirring. The dropping funnel A is charged with 175 g of cyclohexyl methacrylate, 125 g of ethylhexyl methacrylate, 148.5 g of isobutyl methacrylate, 4 g of dimethylaminoethyl methacrylate, 2.5 g of methacrylic acid and 45 g of 4-hydroxybutyl acrylate, and the dropping funnel B has a Cactus solvent P. 105 g of -20 and 10 g of Kayaester O were charged and added dropwise from a dropping funnel A and a dropping funnel B simultaneously at a constant rate over 3 hours.
After 3 hours, after stirring at 110 ° C. for 30 minutes, 25 g of Cactus solvent P-20 and 2.5 g of Kaya ester O are charged into the dropping funnel C and added dropwise at a constant rate over 30 minutes. Then, after further stirring at 110 ° C. for 1.5 hours, the temperature was lowered to room temperature to obtain an acrylic resin solution.
The obtained acrylic resin solution had a heating residue of 50% by mass.

Example 1
(Manufacture and evaluation of coating composition 1 for measurement)
In a 380 ml vessel, 68 g of the acrylic resin solution obtained in Production Example 1 and only 15.4 g of YM1100 (yellow iron oxide manufactured by Titanium Industry Co., Ltd., stearic acid adsorption amount 63 μmol / g) as a coloring pigment, Cactus solvent P-20 (Japan) Energy organic solvent, aliphatic hydrocarbon content ratio is about 70%) 10.0 g, DISPERBYK-112 (Big Pigmy pigment dispersant) 2.0 g, and Dappo SN359 (San Nopco antifoam) 1 0.0 g was charged, glass beads were added and dispersed using a desktop batch type sand mill for 120 minutes, and then the glass beads were removed to obtain a coating liquid. Then, a curing agent was added to 100 parts by mass of the coating liquid. Takenate D-178N (Mitsui Takeda Chemical Polyisocyanate) 5 parts by weight and Cactus Solvent P Mixing a 20,5 parts by weight and stirred to get a measurement coating composition 1.
The obtained coating composition for measurement 1 is sampled on a sheet mesh to prepare a spectroscopic sample, and a 50,000-fold micrograph is taken using a JEM-200CX (transmission electron microscope manufactured by JEOL), and YM1100 By measuring the long side length and the short side length, it was found that the ratio of long side length / short side length was 2.
(Coloring paint composition 1)
Instead of only YM1100 as the coloring pigment, 6.6 g of YM1100, 3.0 g of Shannin Blue 5159Y (copper phthalocyanine blue manufactured by Dainichi Seika Co., Ltd.) and 5.8 g of CR-95 (titanium dioxide manufactured by Ishihara Sangyo Co., Ltd.) In the same manner as in the production of the coating composition for measurement, after obtaining a coating liquid, Takenate D-178N and Cactus Solvent P-20 were mixed and stirred in the same manner to obtain a colored coating composition 1. .

Example 2
YM1100 was slurried using clean water and adjusted to 30 g / L as a pigment. The slurry was stirred and held at 40 ° C. and pH 3.5 for 120 minutes, and then filtered, washed, dried and pulverized to obtain a YM1100-treated product 1 having a stearic acid adsorption amount of 42 μmol / g.
A coating composition for measurement 2 was obtained in the same manner as in Example 1 except that YM1100-treated product 1 was used instead of YM1100. Further, the long side length and the short side length of the YM1100-treated product 1 were measured in the same manner as in Example 1 except that the measurement coating composition 2 was used instead of the measurement coating composition 1, and the long side length was measured. / The short side length ratio was found to be 2.
Further, a colored coating composition 2 was obtained in the same manner as in Example 1 except that the YM1100 treated product 1 was used instead of YM1100.

Example 3
YM1100 was slurried using clean water and adjusted to 30 g / L as a pigment. The slurry was stirred and held at 80 ° C. and pH 11.0 for 120 minutes, and then filtered, washed, dried and pulverized to obtain YM1100-treated product 2 having a stearic acid adsorption amount of 87 μmol / g.
A coating composition for measurement 3 was obtained in the same manner as in Example 1 except that YM1100-treated product 2 was used instead of YM1100. Further, the long side length and the short side length of the YM1100-treated product 2 were measured in the same manner as in Example 1 except that the measurement coating composition 3 was used instead of the measurement coating composition 1, and the long side length was measured. / The short side length ratio was found to be 2.
Further, a colored coating composition 3 was obtained in the same manner as in Example 1 except that YM1100-treated product 2 was used instead of YM1100.

Comparative Example 1
A coating composition for measurement 4 was obtained in the same manner as in Example 1 except that Bayferrox 915 (Yellow iron oxide manufactured by LANXESS, stearic acid adsorption amount 26 μmol / g) was used instead of YM1100. Further, the long side length and the short side length of Bayferrox 915 were measured in the same manner as in Example 1 except that the measuring coating composition 4 was used instead of the measuring coating composition 1, and the long side length / short side length was measured. The length ratio was found to be 2.
Further, a colored coating composition 4 was obtained in the same manner as in Example 1 except that Bayferrox 915 was used instead of YM1100.

Comparative Example 2
A coating composition 5 for measurement was obtained in the same manner as in Example 1 except that TSY-1 (yellow iron oxide manufactured by Toda Pigment Co., Ltd., stearic acid adsorption amount 67 μmol / g) was used instead of YM1100. Further, the long side length and the short side length of TSY-1 were measured in the same manner as in Example 1 except that the measurement coating composition 5 was used instead of the measurement coating composition 1, and the long side length / It was found that the short side length ratio was 7.
Moreover, it replaced with YM1100 and the colored coating composition 5 was obtained like Example 1 except having used TSY-1.

(Evaluation of color separation)
A 20 cm × 30 cm tin plate was placed horizontally, 3 g of the colored coating composition 1 obtained in Example 1 was weighed out, and applied uniformly using a brush to prepare a coated plate.
Four hours after producing the coated plate, 2 g of the colored coating composition 1 was weighed and applied again by brush so as to be uniform with respect to the half area of the coated plate. After the coated plate was dried at 23 ° C. for one day, the difference in coating color (presence / absence of color separation) between the part painted once and the part painted twice was evaluated. . The evaluation criteria were as follows.
A: There is no difference in coating color. B: There is almost no difference in coating color. Δ: There is a slight difference in coating color. X: The evaluation results obtained with a significant difference in coating color are shown in Table 1. In addition, the difference in the color by the incident angle of the light of the obtained coating plate and the viewing position was not observed.

Thereafter, the difference in coating color due to color separation was similarly evaluated for the colored coating compositions 2 to 5 obtained in Examples 2 and 3 and Comparative Examples 1 and 2.
The obtained evaluation results are shown in Table 1. In addition, although the difference in the color depending on the incident angle and the viewing position of the light of the coating plate obtained from Examples 2 and 3 and Comparative Example 1 was not observed, in the coating plate obtained from Comparative Example 2, A difference in color was observed.

As is apparent from Table 1, Examples 1, 2 and 3 using the colored coating compositions 1 to 3 contained in the colored coating composition of the present invention have specific stearic acid adsorption amounts and long sides. Since it contained special yellow iron oxide having a ratio of long / short side length, the obtained coated plate showed no difference in coating color due to color separation. However, the coating plates obtained in Comparative Examples 1 and 2 using the colored coating compositions 4 and 5 not included in the colored coating composition of the present invention showed a difference in coating color due to color separation.

The colored coating composition of the present invention can be suitably used for coating interior and exterior of buildings.

Claims (5)

A colored coating composition containing yellow iron oxide,
At least a part of the yellow iron oxide is special yellow iron oxide having a stearic acid adsorption amount of 35 to 100 μmol / g and a ratio of long side length / short side length of 1 to 3,
Furthermore, the coloring coating composition characterized by containing coloring pigments other than yellow iron oxide, and binder resin. The colored coating composition according to claim 1, wherein the content of the special yellow iron oxide is 50% by mass or more in the total yellow iron oxide contained in the colored coating composition. The colored coating composition according to claim 1 or 2, wherein the total color pigment volume concentration is 20% or less. The colored coating composition according to claim 1, 2 or 3, which is an organic solvent-type coating. A colored coating film obtained by the colored coating composition according to claim 1, 2, 3 or 4.