JP3967598B2 - Alumina and silica wet processing method of inorganic pigment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to alumina及beauty shea silica wet treatment method of the inorganic pigments to improve various coating suitability, the details alumina及beauty shea silica inorganic pigment surface by a simple method using an alumina sol及beauty shea Rikazoru It is related with the processing method made to deposit.
[0002]
[Prior art]
In order to improve the dispersibility of the pigment by modifying the surface state of the inorganic pigment, the surface of the inorganic pigment has been conventionally treated with alumina or silica.
The conventional surface treatment of inorganic pigments by alumina or silica by a wet method is a method in which alumina or silica formed by a wet method is deposited on the surface of the inorganic pigment. For example, aluminum chloride, sulfuric acid is used as an alumina forming material. Aluminum metal salts such as aluminum and aluminum nitrate are used, and water glass such as sodium silicate is used as the silica forming material. In order to deposit alumina or silica on the surface of inorganic pigment using these, the peptization of the pigment and the dissolution of the aluminum metal salt, etc. are sufficiently performed, and the metal salt and the aqueous alkali solution, or the alkali silicate aqueous solution and the dilute sulfuric acid aqueous solution are mixed. The reaction is carried out by dropping or flowing simultaneously while controlling the pH of the reaction system. Further, in the silica treatment, it is necessary to keep the slurry of the inorganic pigment at 80 ° C. and the pH in the range of 9 to 10.5, the degree of difficulty of the treatment process is high, and the treatment time is also long. In terms of equipment, a peptization tank for pigments, a dissolution tank for raw materials, and a reaction tank capable of temperature control are required.
[0003]
[Problems to be solved by the invention]
Accordingly, the present invention purposes, for example, the conventionally been made wet improve the dispersibility of the improvement due to the relative varnish purpose inorganic pigments alumina及beauty shea silica wet processing equipment and on the reaction control Choice of Method problems have been improved to provide a wet treatment method of depositing alumina及beauty shea silica simultaneously on the surface of two kinds of inorganic pigments in simple equipment and processing method in room temperature.
As a result of repeated studies to achieve this object, the present inventors have used inorganic sols and silica sols as the raw materials for alumina and silica, respectively, so that it is easy to use inorganic pigments without requiring special equipment and reaction conditions. The present invention has been completed by finding that the surface can be treated with alumina or silica, and the obtained surface-treated pigment has excellent paint suitability.
[0004]
[Means for Solving the Problems]
The above object can be achieved by the present invention described below. That is, the present invention, yellow iron oxide, red iron, iron black, selected from composite oxide pigments take chromium oxide green, and rutile or spinel type crystal structure of two or more metal oxides two In the method of simultaneously treating the surface of various types of inorganic pigments with alumina and silica, two types of inorganic pigments are prepared by bringing alumina sol, silica sol and inorganic pigment into contact with each other in an aqueous medium at room temperature, and adjusting the pH of the system to neutral. This is an alumina / silica wet processing method of an inorganic pigment, characterized in that alumina and silica are deposited simultaneously on the surface.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in further detail below.
The inorganic pigments to be surface-treated in the present invention are yellow iron oxide, dial, iron black, chromium oxide green, and various complex oxide pigments having a rutile or spinel crystal structure of two or more metal oxides. Etc.
[0006]
The alumina sol used in the present invention is a conventionally known alumina hydrate used as a raw material for glass, fiber and other surface coatings, inorganic binders and high-purity alumina, and usually has a particle size of 5 to 200 μm. The product is used in a state of being colloidally dispersed (suspended) in acidic water. Alumina sol is also called colloidal alumina. Commercially available alumina sol can be used.
[0007]
The silica sol used in the present invention is a conventionally known colloidal silica used as a raw material for surface coatings such as paper and fibers, inorganic binders and high-purity silica, and usually a silica hydrate having a particle size of 5 to 30 μm. Is used in a state of being colloidally dispersed (suspended) in acidic or alkaline water. Silica sol is also called colloidal silica. A commercially available silica sol can also be used.
[0008]
Alumina及beauty shea silica wet surface treatment method of the inorganic pigments of the present invention, in an aqueous medium by contacting the two kinds of inorganic pigment particles and alumina sol及beauty shea Rikazoru is their methods for simultaneously deposited on the pigment surface.
In the surface treatment of inorganic pigments, alumina sol及Beauty shea Rikazoru is added a stock solution so as to have a predetermined solids in inorganic pigments deflocculated slurry (solids 5 to 50% by weight) or suitably diluted, Thoroughly mixed. The amount of alumina sol及beauty shea Rikazoru is not particularly limited, 0.1 to 50 wt% are preferred with respect to the inorganic pigment, more preferably from 5 to 20% by weight (both dry basis). If the amount used is too small, the surface treatment effect is insufficient, and if it is too large, problems such as increasing the viscosity of the paint and lowering the color density are undesirable.
[0009]
To simultaneously depositing alumina及beauty shea silica into two types of the inorganic pigment particle surface, destroying a stable dispersion state of the hydrated alumina colloidal particles及beauty hydrated silica colloidal particles in the processing system, these inorganic pigments It is necessary to simultaneously deposit and adhere to the surface (deposition).
Therefore, when alumina sol is used, the pH of the treatment system (mixture of inorganic pigment peptization slurry and alumina sol) is adjusted to alkalinity by adding alkali. When silica sol is used, the pH of the treatment system is adjusted to neutral or alkaline by adding acid or alkali. Further, when alumina sol and silica sol are used in combination, the pH of the treatment system is made neutral. As the acid solution, in order to avoid deterioration of the pigment, it is preferable to use a 1 to 2% by weight sulfuric acid aqueous solution or an acetic acid aqueous solution. Further, as the alkaline aqueous solution, it is preferable to use a 1 to 5% by weight aqueous sodium hydroxide solution. The acidic and alkaline pH values described above vary depending on the alumina sol aqueous dispersion or silica sol dispersion used, and are not particularly limited. Alumina及beauty shea silica suitable for the dispersions to be used it is necessary to set the pH to deposit simultaneously.
After treatment, washed well with water, alumina及Beauty shea silica treated inorganic pigments of the present invention is obtained by drying and grinding.
[0010]
【Example】
Next, the present invention will be described in more detail with reference examples and examples. In the text, “part” or “%” is based on weight unless otherwise specified.
[0011]
Reference example 1
A pigment slurry is prepared by adding 300 parts of yellow iron oxide to 800 parts of water with stirring. To this slurry, 90 parts of an alumina sol aqueous dispersion (alumina sol 200 manufactured by Nissan Chemical Co., Ltd .: Al ₂ O ₃ content 10%) was diluted 2-3 times with water, stirred for 20 to 60 minutes, and then 2% water. The pH is adjusted to around 9 by adding 50 parts of an aqueous sodium oxide solution. The obtained slurry was washed and filtered to 300 μs / cm or less, dried at 100 to 120 ° C. to a moisture content of 1% or less, and 303 parts of alumina-treated pigment was obtained by dry grinding.
[0012]
(1) Test with acrylic lacquer paint Take 4 parts of the obtained treated pigment for paint test, put 10 parts of commercial acrylic lacquer (solid content 33%), 2 parts of thinner and 45 parts of glass beads in a 70cc mayonnaise bottle. Dispersed for 1 hour with a paint shaker. After completion of the dispersion, 30 parts of the acrylic lacquer was further added, and the pigment content was adjusted to 30 parts with respect to 100 parts of the resin solid content to prepare a test paint.
[0013]
Next, a part of the prepared paint was taken in a separately prepared glass bottle, and the state of sedimentation was observed.
On the other hand, the obtained test coating material was developed on art paper with a 6 mil applicator to prepare a color developing sheet for evaluation. An untreated yellow iron oxide paint was prepared in the same manner, and a comparative color-extracting sheet was prepared. As a result of comparing the produced color-treated sheet of the surface-treated pigment and the developed color-treated sheet of the untreated pigment, it was clear that the gloss and the dispersibility were improved in the paint using the surface-treated pigment. Further, when the state of sedimentation after one week was confirmed, sedimentation was slightly observed in the paint using the untreated pigment, but no sedimentation was confirmed in the paint using the surface-treated pigment.
[0014]
(2) Test with Melamine / Alkyd Paint Further, as a paint test, the same test was conducted for melamine / alkyd varnish. That is, 4 parts of the obtained treated pigment were taken for the paint test, and 4.8 parts of a commercially available melamine resin (solid content 60%), 3 parts of thinner and 45 parts of glass beads were placed in a 70 cc mayonnaise bin with a paint shaker. Dispersed for 1 hour. After completion of the dispersion, 11.6 parts of a commercially available alkyd resin (solid content 60%) was added to adjust the pigment content to 40 parts with respect to 100 parts of the resin solid content to prepare a test paint.
Next, a part of the prepared paint was taken in a separately prepared glass bottle, and the state of sedimentation was observed. The obtained test paint was developed on art paper with a 6 mil applicator, air-dried, and baked at 130 ° C. for 20 minutes to prepare a color display sheet for evaluation. An untreated yellow iron oxide paint was prepared in the same manner, and a comparative color-extracting sheet was prepared. When the obtained color-treated sheet of the surface-treated pigment and the color-treated sheet of the untreated pigment were compared, it was clear that the gloss and the dispersibility were improved in the paint using the surface-treated pigment. Moreover, when the state of sedimentation after one week was confirmed, slight sedimentation was observed in the paint using the untreated pigment, but no sedimentation was confirmed in the paint using the surface-treated pigment.
[0015]
(3) Test with fluororesin paint Furthermore, as a paint test, the same test was conducted with respect to the fluororesin paint. That is, 4 parts of the obtained treated pigment were taken for the paint test, 3.3 parts of a commercially available melamine resin (solid content 60%), 3.3 parts of Lumiflon type fluororesin (solid content 60%), thinner 3 And 45 parts of glass beads were placed in a 70 cc mayonnaise bottle and dispersed with a paint shaker for 1 hour. Furthermore, 10 parts of the said fluororesin was added after completion | finish of dispersion | distribution, and it adjusted so that a pigment content might be 40 parts with respect to 100 parts of resin solid content, and produced the coating material for a test. Next, a part of the prepared paint was taken in a separately prepared glass bottle, and the state of sedimentation was observed. The obtained test paint was developed on art paper with a 6 mil applicator, air-dried, and baked at 140 ° C. for 20 minutes to prepare a color developing sheet for evaluation. An untreated yellow iron oxide paint was prepared in the same manner, and a comparative color-extracting sheet was prepared. When the developed color-treated sheet of the surface-treated pigment and the developed color-treated sheet of the untreated pigment were compared, it was clear that the gloss and the dispersibility were improved in the paint using the surface-treated pigment. Further, when the state of sedimentation after one week was confirmed, sedimentation was slightly observed in the paint using the untreated pigment, but no sedimentation was confirmed in the paint using the surface-treated pigment.
[0016]
Reference example 2
Add 200 parts of iron black to 200 parts of water while stirring to prepare a pigment slurry. 25 parts of silica sol aqueous dispersion (DuPont Ludox HS-40: SiO ₂ content 40%) is added to this slurry and stirred for 20-60 minutes. The obtained slurry was washed with water to 300 μs / cm or less and filtered, and then dried at 100 to 120 ° C. to 1% or less of water, and 206 parts of treated pigment was obtained by dry grinding. Thereafter, test coatings in which the coating film-forming resins were acrylic lacquer, melamine / alkyd resin, and fluororesin were prepared in the same manner as in Reference Example 1, and each paint was developed to prepare an evaluation sheet. In the same manner, an untreated iron black paint was prepared, and a color developing sheet for comparison after color development was prepared. When the developed color-treated sheet of the surface-treated pigment and the developed color-treated sheet of the untreated pigment were compared, it was clear that the gloss and the dispersibility were improved in the paint using the surface-treated pigment. Further, when the state of sedimentation after one week was confirmed, sedimentation was slightly observed in the paint using the untreated pigment, but no sedimentation was confirmed in the paint using the surface-treated pigment.
[0017]
Example 1
150 parts of a Co—Al complex oxide blue pigment is added to 600 parts of water while stirring, and then 150 parts of ultramarine blue is added to prepare a pigment slurry. To this slurry, 30 parts of the same silica sol aqueous dispersion as in Reference Example 2 is added and stirred for 20 to 60 minutes. Next, 20 parts of the same alumina sol aqueous dispersion as in Reference Example 1 is diluted with water 2-3 times and added, stirred for 20 to 60 minutes, and the pH is adjusted to around 7 with a 2% aqueous sulfuric acid solution. The obtained slurry was washed with water and filtered to 300 μs / cm or less, dried at 100 to 120 ° C. to 1% or less of moisture, and 307 parts of treated pigment was obtained by dry grinding.
[0018]
Hereinafter, test coatings in which the coating film-forming resins were acrylic lacquer, melamine alkyd resin, and fluororesin were prepared by the same operation as in Reference Example 1, and each coating material was developed to prepare an evaluation sheet. Similarly, an untreated Co-Al composite oxide blue pigment and ultramarine blue were mixed in a one-to-one dry paint to produce a paint, and after color development, a comparative color developing sheet was prepared. When the developed color-treated sheet of the surface-treated pigment and the developed color-treated sheet of the untreated pigment were compared, it was clear that the gloss and the dispersibility were improved in the paint using the surface-treated pigment. Further, when the state of sedimentation after one week was confirmed, slight sedimentation was observed in the paint using the untreated pigment, but no sedimentation was confirmed in the paint using the surface-treated product.
[0019]
Example 2
To 600 parts of water, 150 parts of a Ti—Zn—Co—Ni composite oxide green pigment is added with stirring, and then 150 parts of chromium oxide green is added to prepare a pigment slurry. To this slurry, 30 parts of the same silica sol aqueous dispersion as in Reference Example 2 is added and stirred for 20 to 60 minutes. Next, 20 parts of the same alumina sol aqueous dispersion as in Reference Example 1 is diluted 2-3 times with water and added, stirred for 20 to 60 minutes, and the pH is adjusted to around 7 with a 4% aqueous sodium hydroxide solution. The obtained slurry was washed with water and filtered to 300 μs / cm or less, dried at 100 to 120 ° C. to 1% or less of moisture, and 307 parts of treated pigment was obtained by dry grinding.
[0020]
Hereinafter, test coatings in which the coating film-forming resins were acrylic lacquer, melamine alkyd resin, and fluororesin were prepared by the same operation as in Reference Example 1, and each coating material was developed to prepare an evaluation sheet. Similarly, a pigment coating is prepared by dry-mixing an untreated Ti—Zn—Co—Ni-based composite oxide green pigment and chromium oxide green on a one-to-one basis. Created. When the developed color-treated sheet of the surface-treated pigment and the developed color-treated sheet of the untreated pigment were compared, it was clear that the gloss and the dispersibility were improved in the paint using the surface-treated pigment. Further, when the state of sedimentation after one week was confirmed, sedimentation was slightly observed in the paint using the untreated pigment, but no sedimentation was confirmed in the paint using the surface-treated pigment.
[0021]
【The invention's effect】
According to the above invention, surface-treated with alumina及beauty shea States, dispersibility, dispersion stability, precipitated, inorganic pigments color separation and the like are improved is provided. The pigment obtained by the surface treatment method of the present invention is suitable for coloring in water / oil paints, resins, inks and building materials.

Claims (2)

  The surface of two types of inorganic pigments selected from yellow iron oxide, petal, iron black, chromium oxide green, and complex oxide pigments with two or more metal oxide rutile or spinel crystal structures. In the method of simultaneously treating with alumina and silica, alumina sol, silica sol, and inorganic pigment are brought into contact with each other in an aqueous medium at room temperature, and the pH of the system is adjusted to neutral so that alumina and silica are deposited on the surface of two kinds of inorganic pigments. A method for wet-treating an inorganic pigment with alumina / silica, characterized by depositing simultaneously. Surface-treated inorganic pigments of alumina及beauty shea silica obtained by the method of claim 1.