JPH0416404B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an extender pigment whose main component is an amorphous aluminosilicate. Generally, extender pigments are non-coloring pigments,
It is used in conjunction with other coloring pigments in paint and printing ink formulations or as a base for lake pigments to provide effective spreading of color pigments. It exerts effects such as reinforcing the paint film, smoothing the surface of the base and paint film, and giving appropriate viscosity and fluidity to the paint and printing ink. It is necessary for the pigment to meet the following requirements. It should be as transparent as possible in a vehicle such as linseed oil or varnish; The pigment particles should be fine-grained, easy to mix with vehicles and other pigments, and have good dispersibility; The oil absorption value should be appropriate. , the desired flow characteristics can be obtained with an appropriate amount; it is insoluble in vehicles and solvents, and it has no reactivity with them; it is resistant to light, heat, chemicals, etc.; it improves the drying properties of printing inks. No inhibition; No toxicity; etc. Conventionally, barium sulfate, calcium carbonate, alumina white, white carbon, etc. have been mainly used as extender pigments, but these extender pigments have advantages and disadvantages, and none of them are overall satisfactory. Nakatsuta. That is, barium sulfate has been used as an extender pigment for a long time, but when kneaded with linseed oil, it becomes a translucent paste, which is easy to knead, but is not very suitable as a general-purpose ink. Calcium carbonate is also easy to mix, but it is translucent in linseed oil, making it unsuitable for printing inks that require a high degree of transparency. It also has the disadvantage that it tends to produce a slightly matte coating. When alumina white is kneaded with linseed oil, a nearly transparent paste is obtained, but when kneaded with a varnish with a high acid value, it has the disadvantage of causing reburring and slowing down the drying of the ink. Furthermore, the gloss of the coating film is likely to be lost, and other pigments may become discolored. White carbon, on the other hand, is quite transparent in the vehicle, but has significantly higher oil absorption values (100-200
Since the viscosity increases with the addition of a small amount (ml/100g), the amount added is limited to a small amount, which has the disadvantage that a sufficient color spreading effect on colored or white pigments and a reinforcing effect on the coating film cannot be obtained. In addition, it has been known that a certain type of amorphous aluminosilicate fine powder (zeolex) is used as a filler in paints, but this type of aluminosilicate is different from zeolite and is rather similar to white carbon. and the diameter of the primary particle is 0.02~
Made of ultrafine particles of 0.04 μm, the oil absorption value is approximately 100.
~150ml/100g, and the structure and properties of the substance, purpose of use, effects, etc. are also significantly different from the extender pigment of the present invention. The present inventors have conducted various experiments and studies to develop a new high-performance extender pigment that overcomes many of the drawbacks of conventional extender pigments. The present invention was completed based on the discovery that the resulting amorphous aluminosilicate and its surface-modified product are extremely suitable as extender pigments. That is, the present invention has an oil absorption value of 10 to 80 ml/100 g, which is mainly composed of amorphous aluminosilicate obtained by acid treatment of zeolite,
It is an extender pigment characterized by having a refractive index value of 1.42 to 1.53. Generally, zeolite has the general formula (1.0±0.2)
M ₂ O・Al ₂ O ₃・xSiO ₂・yH ₂ O (where M is Na or an equivalent monovalent or polyvalent metal, x is often a value of 1.5 to 20, and y is a value of 0 to 10). It is an aluminosilicate with a unique crystal structure that can be identified by chemical composition and X-ray diffraction, and is known in a variety of forms, including natural minerals and synthetic products (usually M is Na ). Zeolites are also generally known to have unique adsorption and ion exchange properties based on their unique crystal structures, and a variety of uses have been developed that take advantage of these properties. Therefore, the extender pigment according to the present invention is an acid-treated product of the zeolite that substantially has a skeleton in the form of basic particles, and is an amorphous product having an oil absorption amount and a refractive index desirable as an extender pigment. It is a high quality aluminosilicate. Therefore, the extender pigment of the present invention will be described in detail below along with its manufacturing method. According to the study results of the present inventors, surprisingly, type A zeolite (Na ₂ O・Al ₂ O ₃・2SiO ₂・
4.5H ₂ O) and X-type zeolite (Na ₂ O・Al ₂ O ₃・
Component _molar ratio _{(SiO 2 /}
Although zeolites with a relatively small value of Al ₂ O ₃ ) become clearly amorphous in X-rays when treated appropriately with acid, the shape and size of their primary particles change. It was found that the state of the particles, such as grains, was hardly changed by the acid treatment, and the state of the particles before the acid treatment was maintained almost as it was. The present invention is based on the application of this fact, and although the acid treatment of zeolite makes the chemical characteristics completely different from that of amorphous aluminosilicate, the basic particle characteristics of the raw zeolite Therefore, as an extender pigment, it is highly dependent on the physical properties of the raw zeolite, and it is necessary to have appropriate properties such as oil absorption and refractive index, as well as the particle state of the zeolite itself. be. Therefore, the zeolite used as a raw material in the present invention must first have a relatively small component molar ratio (SiO ₂ /Al ₂ O ₃ ) as described above, and must have a uniform and fine particle state. It is necessary. In this case, the term "uniform and fine particles" means a particle size distribution in which the particle size portion of 10 μm or more is 1% or less, and the particle size portion of 6 μm or less is 85% or more. In addition, the zeolite used as a raw material in the present invention has an oil absorption value of 10 to 80ml/100g.
It is desirable that the degree of From this point of view, various types of zeolite have been suggested as suitable as raw materials for producing the extender pigment of the present invention, including A-type zeolite, X-type zeolite, P-type zeolite, sodalite, analcyme, etc. are particularly preferred, and one or more of these can be used. Further, uniform fine zeolite particles having the above particle size and oil absorption values can be prepared by various methods, such as JP-A-57-3713 and JP-A-57-3713.
Synthetic zeolites such as A-type zeolite and X-type zeolite obtained by methods such as No. 166311 are particularly suitable. Furthermore, some or most of the Na ₂ O components in these zeolites are converted to Na ⁺ by an ion exchange reaction.
Metal-substituted zeolites substituted with other cations can also be used. In this case, the types of cations other than Na ⁺ are
Monovalent cations such as NH ₄ ⁺ , Li ⁺ , K ⁺ , Mg ²⁺ ,
Various divalent cations such as Ca ²⁺ , Br ²⁺ , Ba ²⁺ , Zn ²⁺ , Cd ²⁺ , Pb ²⁺ etc. can be mentioned, but it depends on the type of cation and the degree of substitution. It is possible to adjust the refractive index of the zeolite particles to some extent. Although various methods are possible for acid-treating such zeolite, it can usually be carried out as follows. That is, the above zeolite particles are dispersed in water to form an aqueous suspension, and an acid or acidic salt solution is gradually added to this while stirring, until the pH value of the suspension is at least 4.5. After adjusting the amount added so as to achieve the desired amount, solid-liquid separation and washing are performed, and steps such as drying and pulverization are added as necessary. Examples of acids or acidic substances used here include mineral acids such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, carbonic acid, and sulfurous acid; organic acids such as formic acid, acetic acid, and oxalic acid;
Other examples include various acid salts such as sodium bisulfate and acidic sodium phosphate, but are not limited thereto. If the final pH value is less than 4.5, it is unsuitable because the zeolite particle state changes significantly or the entire particle dissolves or disappears, destroying the bulk zeolite skeleton.On the other hand, if the pH value is higher than 9 In this case, the degree of amorphization becomes insufficient. Therefore, especially PH
A weakly acidic range of 5 to 8 is preferred. The degree of amorphousness is evaluated by the presence or absence and strength of diffraction lines in an X-ray diffraction diagram, and in the extender pigment of the present invention, the height of the diffraction line is approximately 1 times higher than that of the original zeolite. means less than /2. On the other hand, the refractive index value is an important property that governs the transparency of extender pigments, and the closer the refractive index value of the linseed oil or varnish used, the better the transparency can be obtained. In order to obtain good transparency, it is necessary that the refractive index value (n _D ) be between 1.42 and 1.53. In this regard, the refractive index of the product obtained by the above acid treatment of zeolite will be within this range, but if necessary, the degree of substitution by cations and the amount of silica in the silica coating treatment described below may be adjusted. Since the value of the refractive index can be adjusted to some extent by changing the ratio, etc., a higher degree of transparency can be exhibited for a specific vehicle. The extender pigment according to the present invention is the above-mentioned specific amorphous aluminosilicate, but it also includes those modified as necessary to further improve the pigment properties. Typical examples of such modified materials include those with a continuous film of dense and fine amorphous silica, or fine white metal hydrated oxides such as aluminum, titanium, zirconium, antimony, etc. Examples include precipitation of hydrous oxides, or modification of particle surfaces with surfactants, dispersants, etc. Therefore, for example, when applying silica coating treatment,
After acid treatment by adding acid or acidic salts to an aqueous suspension of zeolite, activated silica is gradually added at a temperature of 60°C or higher, or activated silica is gradually added to an alkali silicate and acid. By allowing this to occur, the particle surface can be covered with a dense amorphous silica film. The amount of silica added or generated at this time is often 2% for the amorphous aluminosilicate.
A sufficient coating effect can be obtained at silica of 30 to 30% by weight, but as the amount of silica increases, the refractive index value of the particles tends to increase somewhat. Amorphous aluminosilicate particles coated with silica have extremely inert surfaces and are more resistant to light, heat, and chemicals, regardless of the type of zeolite used as raw material. Therefore, even if it is kneaded with a vehicle with a high acid value or various formulations, its performance as a paint or printing ink will not deteriorate. Similarly, in the coating treatment of a metal hydrated oxide, a corresponding aqueous metal salt solution may be added to deposit the hydroxide produced by hydrolysis. As is clear from the above description, the following points are pointed out as characteristics of the extender pigment of the present invention. It is far more transparent than conventional extender pigments such as barium sulfate and calcium carbonate. In particular, the extender pigments of the present invention, whose refractive index is adjusted to a value similar to that of linseed oil and varnish used in paints and printing inks, are almost completely transparent in these vehicles. The pigment particles are fine-grained, have an oil absorption value equivalent to that of general pigments, are easy to knead with vehicles and other pigments, and have good particle dispersibility. This point is markedly different from alumina white and white carbon, which have large oil absorption values. Since the specific gravity value is relatively small at about 2, the same filling effect can be obtained with about 1/2 the amount used compared to barium sulfate. Insoluble in vehicles and solvents. It is resistant to light and heat. In particular, zeolite particles coated with dense amorphous silica have extremely inert surfaces, are not attacked by various chemicals, and do not inhibit the drying properties of printing inks. Therefore, even if it is kneaded with oil having a high acid value, it will not cause reburring, solidify the surface, or promote gelation. Non-toxic. The extender pigment of the present invention, which has many of these characteristics, can be used not only for general paints and printing inks, but also for special paints and high-grade printing inks that require high quality characteristics, or as transparent pigments for lake pigments. It can be said that it is an epoch-making extender pigment that can be widely used as a sexual base material. Examples will be shown below, and the results were evaluated using the following test method. Oil absorption: 19 of JISK5101-78 Specific gravity: 17 Refractive index: Measured by Larsen's oil immersion method using an Atsube refractometer. Particle size distribution: Measured using a Coulter Counter (manufactured by Coulter Electronics) with an aperture tube diameter of 20 μm. Color difference: Digital colorimeter (manufactured by Suga Test Instruments Co., Ltd.)
The color difference was measured using Transparency: Using the black side of the hiding power measurement paper (Note) as a reference, the color difference of each sample pigment applied on the black side was measured, and those with a small color difference were defined as having high transparency. (Note) Hiding power measurement paper Art paper with white and black sides (approx. 217 x 197 mm)
The 45 degree diffuse reflectance was 79.69% for the white surface and 1.48% for the black surface. Example 1 50 g of Na-A zeolite was weighed in a 500 c.c. beaker, and 200 g of water was added to prepare 250 g of slurry with a zeolite concentration of 20%. Furthermore, the pH of this slurry is
It was 11.7. While stirring the slurry, 250 g of 4% sulfuric acid was added thereto, and stirring was continued for 1 hour after the addition, followed by filtering, washing with water, drying, and pulverization in a conventional manner to obtain an acid-treated product of Na-A type zeolite. Ta. Figure 1 shows an electron microscopy (SEM) photograph of this acid-treated product. When this acid-treated product was subjected to X-ray diffraction (XRD) analysis, no diffraction peaks were observed, and it was clear that it was an amorphous aluminosilicate. Table 1 shows the specific gravity, refractive index, oil absorption, acid treatment conditions, composition, etc. of this acid-treated product.

[Table] The raw material Na-A zeolite can be obtained by reacting a sodium silicate solution and a sodium aluminate solution without back-mixing to form a gel, and then heating and aging it (Japanese Patent Laid-Open No. 57-3713
issue). An electron microscopy (SEM) photograph of the obtained Na-A type zeolite is shown in FIG. It is clear from these photographs that the state of the zeolite particles remains almost unchanged before and after acid treatment. Example 2 Using the same Na-A zeolite as in Example 1, acid treatment was carried out in exactly the same manner as in Example 1, except that 2% sulfuric acid was used instead of 4% sulfuric acid. XRD analysis of the acid-treated product revealed that the intensity of each diffraction peak of Na-A zeolite was reduced to about 1/2 to 1/3, indicating that it contains a large amount of amorphous aluminosilicate. be. Specific gravity of this acid-treated product,
The refractive index, oil absorption, acid treatment conditions, composition, etc. are also shown in Table 1. Example 3 The same Na-A zeolite as in Example 1 was used, and acid treatment was carried out in exactly the same manner as in Example 1, except that 10% phosphoric acid was used instead of 4% sulfuric acid. The obtained acid-treated product showed no diffraction peaks at all in XRD analysis, and it is clear that it is an amorphous aluminosilicate gloss. Specific gravity of this acid-treated product,
The refractive index, oil absorption, acid treatment conditions, composition, etc. are also shown in Table 1. Example 4 Using the same Na-A zeolite as in Example 1, acid treatment was carried out in exactly the same manner as in Example 1, except that 4% phosphoric acid was used instead of 4% sulfuric acid. The obtained acid-treated product was found to be Na-A in XRD analysis.
The intensity of each diffraction peak of the zeolite type zeolite has decreased to about 2/3, and it is clear that the main component is amorphous aluminosilicate. Specific gravity of this acid-treated product,
The refractive index, oil absorption, acid treatment conditions, composition, etc. are also shown in Table 1. Example 5 In the same manner as in Example 1, 50 g of Na-X type zeolite was weighed into a 500 c.c. beaker, and 200 g of water was added to prepare 250 g of slurry with a zeolite concentration of 20%. Note that the pH of this slurry was 11.8. While stirring the slurry, add 250g of 4% sulfuric acid,
After the addition, stirring was continued for 1 hour, followed by filtering, washing with water, drying, and pulverization in a conventional manner to obtain an acid-treated product of Na-X type zeolite. Figure 3 shows an electron microscopy (SEM) photograph of this acid-treated product. X of this acid-treated product.
When RD analysis was performed, a slight diffraction peak of Na-X type zeolite was observed, but its intensity was less than 1/10 in the case of the strongest peak (2θ = 6°), indicating that it was amorphous aluminosilicate. It is clear that salt is the main ingredient. The specific gravity, refractive index, oil absorption, acid treatment conditions, composition, etc. of this acid-treated product are also shown in Table 1. The Na-X type zeolite used as a raw material was prepared by reacting a sodium silicate solution and a sodium aluminate solution without back-mixing to form a gel, and then heating and aging the gel (Japanese Patent Application Laid-Open No. 166311-1982).
issue). Electron microscopy (SEM) of this Na-X type zeolite
A photograph is shown in Figure 4. Comparative Example 1 For comparison, an electron microscopy (SEM) photograph of a commercially available amorphous aluminosilicate (Zeolex) is shown in Figure 5, and its specific gravity, refractive index, oil absorption, composition, etc. are shown in Table 1. show. Table 1 also shows the physical properties of commercially available extender pigments such as white carbon, precipitated barium sulfate, and calcium carbonate. Table 1 shows that the acid-treated zeolite has a specific gravity of about 2, which is smaller than the extender pigment of the comparative example. Furthermore, the refractive index is close to that of linseed oil, and it is clear that when mixed with linseed oil, an almost transparent coating film can be obtained. Also table-
The acid-treated zeolite shown in 1 has a particle size of
It maintains a nearly spherical particle shape of 0.5 to 5 μm,
Since the oil absorption amount is 80 ml/100 g or less, it is clearly distinguished from commercially available amorphous aluminosilicate (particle size 0.02 to 0.04 μm, oil absorption amount 100 ml/100 g or more). As can be seen from Figures 1 to 5, the particle shape of the zeolite acid-treated product of the present invention maintains the original zeolite shape, whereas the commercially available amorphous aluminosilicate It is clear that the salt is an irregular agglomeration of fine particles of less than 0.05 μm. Comparative Example 2 Using the same Na-A zeolite as in Example 1, 4% sulfuric acid was added for acid treatment in the same manner as in Example 1, and sulfuric acid was further added to adjust the pH of the mixed slurry.
After adjusting the temperature to 3.0, stirring was continued for 1 hour.
Thereafter, the acid-treated product was obtained by filtering, washing with water, drying, and pulverizing in a conventional manner. Electron microscopy (SEM) of the acid-treated product obtained
A photograph is shown in Figure 6. In Figure 6, an irregular shape due to dissolution and aggregation of particles was observed due to the pH drop during acid treatment, and the skeleton of the bulk zeolite had disappeared. In this comparative example, not only the yield of the acid-treated product was low, but also the dispersibility as a pigment was poor.

[Table] Test Example 1 Examples 1-
5. Of the comparative examples, the hiding power of precipitated barium sulfate and calcium carbonate was measured. No. 4 linseed oil is used as the vehicle, and the test is carried out according to JISK5115 precipitated barium sulfate test method. When measuring the hiding power of acid-treated zeolite or calcium carbonate, the volume of pigment is added to the mixed paste of precipitated barium sulfate. A paste was prepared by adjusting the concentrations and used for testing. The results are shown in Table-2. From Table 2, it is clear that the amorphous aluminosilicate obtained by acid treatment of zeolite has a hiding power of 1 mm or more, and has extremely superior transparency compared to precipitated barium sulfate and calcium carbonate. .

[Table] Example 6 After treating Na-A type zeolite with an average particle size of 1.02 μm with acid in the same manner as in Example 1, a slurry concentration of 20
% by weight of the slurry was maintained at a temperature of 90° C. while stirring, 6% by weight of sodium silicate aqueous solution as SiO ₂ and 4% sulfuric acid were simultaneously gradually added to carry out silica deposition treatment. Next, the above deposited product was washed with water, dried and pulverized in a conventional manner to obtain an extender pigment. The amount of silica in this pigment was 18.05% by weight as SiO ₂ and the acid resistance was significantly improved. Further, in the same manner as in Test Example 1 above, when its characteristics were examined, the cryptometer scale was 50 mm or more, and the hiding power was 1 or more. The raw material Na-A zeolite was prepared as follows: A sodium silicate aqueous solution and a sodium aluminate aqueous solution were maintained at a molar ratio of SiO ₂ /Al ₂ O _{3 of} 2.0 to form a gel without back mixing. Seshime, then Na
-A type zeolite was synthesized. The average particle diameter of this zeolite was 1.02 μm. Test Example 2 A paste was prepared by kneading 3.0 g of each of the zeolite acid-treated products of Examples 1 to 5 and the extender pigment of the comparative example with 1.8 g of No. 4 linseed oil using a Huber muller, and the paste was placed on the hiding power measurement paper using a film applicator. It was applied to a thickness of 0.075 mm (3 mils). After drying at room temperature, tristimulus values X, Y, and Z of the color of the black side of the hiding power measurement paper were measured using a color difference meter, and L, a, b values, and color difference ΔE were determined from these. Table 3 shows the results.
Shown below. In Table 3, those with a small color difference (△E) compared to the blank (black side of the hiding power measurement paper) have excellent transparency, whereas the black side coated with acid-treated zeolite has a color difference of about 10 or less. The precipitated barium sulfate and calcium carbonate values were 20 or more, which clearly shows that the amorphous aluminosilicate obtained by acid treatment of zeolite has excellent transparency.

[Table] Test Example 3 Using the zeolite acid-treated products of Examples 1 to 6 and the precipitated barium sulfate and precipitated calcium carbonate of Comparative Example 1, each sample was uniformly kneaded with No. 4 linseed oil. Bottle (φ15
The specimen was placed in a sealed container (mm×35H) and a reviving test was performed in a constant temperature bath at 80°C. As a result, no reviving was observed in any of the samples even after 72 hours at 80°C, and the zeolite acid-treated products (amorphous aluminosilicate) of Examples 1 to 6 did not react with precipitated barium sulfate or calcium carbonate. It was found that they had similar stability.

[Brief explanation of drawings]

All of the drawings are electron microscopy (SEM) photographs, with the exception of Figure 6, which is magnified at 5000x. Figures 1 and 3 show extender pigments according to the present invention, Figures 2 and 4 show raw zeolite before acid treatment, Figure 5 shows commercially available amorphous aluminosilicate, and Figure 6 shows extender pigments according to the present invention.
The figure is a micrograph of an acid-treated product in which the zeolite skeleton has been destroyed.

Claims (1)

[Scope of Claims] 1. An amorphous aluminosilicate of a zeolite acid-treated product having substantially the particle state of zeolite, which has an oil absorption value of 10 to 80 ml/100 g, and has a refractive index An extender pigment characterized by having a value of 1.42 to 1.53. 2. The extender pigment according to claim 1, wherein the zeolite is one or more selected from A-type zeolite, X-type zeolite, p-type zeolite, sodalite, and analcyme. 3. The extender pigment according to claim 2, which is a zeolite in which a part or most of the Na ₂ O component of the zeolite is substituted with a cation other than Na ⁺ . 4. The zeolite according to any one of claims 1 to 3, wherein the zeolite has a particle size distribution in which the particle size portion of 10 μm or more is 1% or less, and the particle size portion of 6 μm or less is 85% or more. extender pigment. 5. The extender pigment according to any one of claims 1 to 4, wherein the acid-treated zeolite is coated with dense, fine, amorphous silica or white metal hydrated oxide. 6 Aqueous slurry of zeolite can be made even if the pH is low.
A method for producing extender pigments characterized by acid treatment in a weakly acidic range up to 4.5.