JPH07292280A - Stable copper-containing pigment composition - Google Patents

Abstract

PURPOSE:To obtain a pigment composition improved in pigment characteristics and excellent in stability, dispersibility and flowability by the surface treatment of a copper-containing pigment with an organosilicon compound having a group reactive with an inorganic compound. CONSTITUTION:This pigment composition is obtained by the surface treatment of a copper-containing pigment comprising, e.g. cuprous oxide with at least one organosilicon compound selected from among a chlorosilane, an alkoxysilane and a silane coupling agent, in an amount of at least 0.05wt.% based on the total weight of the composition. For the surface treatment, the copper-containing pigment is coated with the organosilicon compound, or an organic silicon copper compound produced by the reaction of the copper-containing pigment with the organosilicon compound and the hydrolyzate of the organosilicon compound are deposited on the surface of the copper-containing pigment. The surface treating materials may form a substantially continuous coating film or, in some cases, may be present partly as free particles among the pigment particles without forming a substantially continuous coating film. To produce a stable copper-containing pigment composition, for example, an organosilicon compound such as a chlorosilane is incorporated into an aqueous slurry of a copper-containing pigment.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to stable copper-containing pigment compositions. The copper-containing pigment composition according to the present invention can be used for antifouling paints such as ship bottom paints, adhesives, bactericides and the like.

[0002]

2. Description of the Related Art Copper-containing pigments, in particular cuprous oxide, are used as pigments for antifouling paints. Other poorly soluble copper compounds have various properties such as particle size, dispersibility, solubility, acid resistance, and alkali resistance, and although many proposals have been made, they are mostly used as pigments for antifouling paints other than cuprous oxide. Not not.

Recently, environmental problems have become more important,
There has been a growing awareness of the environmental effects of chemical substances and the effects on the human body of long-term ingestion. It was taken up as a problem that organotin compounds were also dissolved in seawater and their concentration in marine organisms became higher than expected, and strict regulations were required for their use. Therefore, cuprous oxide-based paints have been re-evaluated as antifouling paints.

[0004]

However, among the copper-containing pigments, cuprous oxide, which is most typically used, is an unstable compound, and is gradually oxidized and easily changes into copper oxide over time.

Further, the copper-containing pigment generally has a problem that it forms a sulfide by a reaction with hydrogen sulfide gas or changes by reacting with an antifouling agent or resin used in combination.

Further, there is a problem that the elution rate of copper ions into seawater depends on the particle size of cuprous oxide and the vehicle composition, and is difficult to control.

Therefore, a stable copper-containing pigment has been proposed in which the copper-containing pigment contains amorphous silica particles finer than the pigment particles (Japanese Patent Laid-Open No. 289871).

The present invention has been made in view of the above-mentioned conventional techniques, and an object thereof is to provide a stable copper-containing pigment composition which is highly effective in a smaller amount than amorphous silica.

[0009]

That is, the present invention relates to a stable copper-containing pigment composition characterized in that a copper-containing pigment is surface-treated with an organosilicon compound having a reactive group with an inorganic compound. It is a thing.

In the present invention, the copper-containing pigment means an inorganic copper compound which is poorly soluble in water, and examples thereof include copper oxide, basic copper chloride, basic copper sulfate, copper sulfide, copper carbonate, copper thiocyanate,
Examples thereof include copper chromite, copper silicate, copper phosphide, and the like, and these may be one kind or two or more kinds. Of these, cuprous oxide, which is particularly useful as an antifouling pigment, is most preferable from the practical point of view.

The copper-containing pigment composition according to the present invention is obtained by surface-treating a copper-containing pigment with an organic silicon compound having a reactive group with an inorganic compound.

Here, the organosilicon compound having a reactive group with an inorganic compound is one selected from chlorosilane, alkoxysilane or a silane coupling agent, and more specifically, methyltrichlorosilane and methyldichlorosilane. Chlorosilanes such as dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, and diphenyldichlorosilane; tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, Alkoxysilanes such as dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane; vinyl; Rikuroroshiran, vinyltris (beta-methoxyethoxy) silane, vinyltriethoxysilane, vinyl silanes such as vinyl Ritori silane; gamma
-Acrylic silanes such as methacryloxypropyltrimethoxysilane; Epoxysilanes such as β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β
(Aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-
Examples include one or more silane coupling agents selected from aminosilanes such as phenyl-γ-aminopropyltrimethoxysilane.

The surface treatment of a copper-containing pigment with an organosilicon compound having a reactive group with an inorganic compound (hereinafter simply referred to as "organosilicon compound") means that the organosilicon compound is coated on the surface of the copper-containing pigment. Or a hydrolyzate of an organosilicon copper compound and an organosilicon compound produced by the reaction of the copper-containing pigment with the organosilicon compound is deposited on the surface of the copper-containing pigment. These surface treatments are formed as a substantially continuous film, and include cases where a part of them is present as free particles between pigment particles without being formed as a substantial film. The term "substantially continuous coating" means a state in which the surface of the pigment is uniformly covered with the organosilicon compound and the surface of the pigment is barely exposed.

The amount of the organosilicon compound treated with respect to the above pigment is at least 0.05% by weight or more, and preferably 0.2 to 10% by weight based on the total weight. The reason for this depends on the type of copper-containing pigment, the purpose of use, and the content form of the organosilicon compound, but if it is less than 0.05% by weight, the stability and dispersibility of the copper-containing pigment are insufficient, and the upper limit is copper. The solubility is appropriately set to such an extent that the inherent solubility of the contained pigment is moderate, but in many cases, the limit is 20% by weight.

Next, in the method for producing a stable copper-containing pigment according to the present invention, an organosilicon compound such as chlorosilane, alkoxysilane or a silane coupling agent is added to an aqueous slurry of the copper-containing pigment to react with the copper-containing pigment. Then, a part of the surface is made into an organic silicon compound, a method in which the copper-containing pigment and the organic silicon compound are directly mixed in a ribbon blender, a stirring vacuum dryer or the like and reacted. In the present invention, a film can be formed uniformly on the surface of the copper-containing pigment, and a post-treatment step such as washing is performed because hydrochloric acid or lower alcohol is generated in the reaction between the copper-containing pigment and the organosilicon compound. Considering this, the method of is preferable.

In any of the methods, it is desirable that the aqueous suspension of the copper-containing pigment is prepared as an aqueous slurry in which the pigment particles are dispersed as uniformly as possible.

Therefore, in order to effectively redisperse the secondary agglomerated particles, the copper-containing pigment is forced by normal stirring, high-speed stirring, shearing dispersion, ultrasonic dispersion, etc. in the presence of the desired dispersant. It is preferable to disperse them as close to the primary particles as possible by means of physical means.

The slurry concentration of the copper-containing pigment is set depending on the balance between productivity and dispersibility, but is generally 3 to 40% by weight.
The range of is practical.

Although the addition reaction varies depending on the method of addition, the addition reaction may be performed usually at room temperature or under heating with stirring.

After completion of the reaction, after aging if necessary,
A stable copper-containing pigment is obtained by filtration, washing with water, drying and pulverization by a conventional method. If the operation of the spray drying method is applied at the drying stage, the dried product can be directly used as a product.

[0021]

The stable copper-containing pigment according to the present invention has improved pigment characteristics by coating the pigment with an organosilicon compound such as chlorosilane, alkoxysilane or a silane coupling agent. Since it has the effect of being impermeable to stimuli, it exhibits excellent stability, and also exhibits excellent effects on both dispersibility and fluidity.

[0022]

EXAMPLES The stable copper-containing pigment of the present invention will be further described below with reference to examples.

Example 1 1000 g of cuprous oxide powder was dispersed in water to make 20 liter of slurry, which was stirred well at high speed and well dispersed.
A slurry was prepared at a temperature of 50 ° C. 10 g of monochlorotrimethylsilane was added to this slurry in about 15 minutes while controlling.

After the addition was completed, the solution was neutralized with 10% NaOH for 30 minutes until the pH of the solution reached 7.0 and filtered to separate the mother liquor.

The filter cake was dispersed in 20 liters of water, washed, and filtered again. This operation was repeated 3 times.

Next, the obtained filter cake was dried at 100 ° C. for 20 hours by a conventional method, and the dried product was lightly crushed,
A stable cuprous oxide powder coated with 1.0% by weight of the hydrolyzate of monochlorotrimethylsilane was obtained.

Example 2 15 liters of an aqueous solution containing 65 g / liter of NaCl, 250 g / liter of free hydrochloric acid and 5 g / liter of free hydrochloric acid as Cu was placed in an N ₂ atmosphere and then adjusted to pH 10.0 with a 30% aqueous solution of NaOH until the pH became 10.0.
Neutralized in time. 1% 35% HCl to the neutralized slurry
After adding 00 ml, the mixture was aged in an autoclave at 140 ° C. for 12 hours. The reaction solution is washed and filtered to remove cuprous oxide 100
A filter cake consisting of 0 g and 500 g of water was obtained. The obtained cake and 5 g of monomethyltrimethoxysilane were put into a stirring vacuum dryer, and the pressure was 100 torr and 80 to 100 ° C.
After drying for 10 hours, the powder was pulverized to obtain a stable cuprous oxide powder coated with 0.5% by weight of the reaction product of monomethyltrimethoxysilane.

Example 3 1000 g of cuprous oxide was put into a ribbon type blender, and then 30 g of vinyltrimethoxysilane was sprayed and mixed. After further stirring and mixing for 30 minutes after the end of spraying, a stable cuprous oxide powder coated with 3.0% by weight of a reaction product of vinyltrimethoxysilane was obtained.

(Thermal Stability Test) The stable copper-containing pigments obtained in Examples 1 to 3 and the untreated product (cuprous oxide) were dried at a humidity of 9
It was placed in an oven at 5% and a temperature of 40 ° C., and the color change every 24 hours was visually observed. The evaluation was performed in three stages. The results are shown in Table 1.

◎ ・ ・ ・ No change ○ ・ ・ ・ Slightly blackened × ・ ・ ・ Remarkably blackened

(Oil Absorption Test) The stable copper-containing pigments and untreated products (cuprous oxide) obtained in Examples 1 to 3 were placed on a glass plate, oil was added dropwise to boiled linseed and kneaded with a copper spatula. The volume of the linseed oil when it became putty is expressed by% of the sample weight (ml / 100 g). The results are shown in Table 1.

(Dispersibility / Flowability Test) The stable copper-containing pigments and untreated products (cuprous oxide) obtained in Examples 1 to 3 were measured for repose angle by a rotating cylinder method, and the following three steps were carried out. Evaluate dispersibility and liquidity. The results are shown in Table 1.

◎ ・ ・ ・ ・ ・ Repose angle 50 ° or less ○ ・ ・ ・ ・ ・ Repose angle 50 ° to 60 ° × ・ ・ ・ ・ ・ Repose angle 60 ° or more

(Chemical resistance test) The stable copper-containing pigments and untreated products (cuprous oxide) obtained in Examples 1 to 3 were made into a paint by using a high solid lacquer, and then applied on a glass plate and dried. Drop 1 drop of hydrogen sulfide water on the coating film, wipe off after 1 hour,
The color of the coating film was observed. The results are shown in Table 1.

◎ ・ ・ ・ No change ○ ・ ・ ・ Slightly blackened × ・ ・ ・ Remarkably blackened

[0036]

[Table 1]

[0037]

INDUSTRIAL APPLICABILITY The copper-containing pigment according to the present invention has particularly improved heat resistance and at the same time improved dispersibility and fluidity.

Therefore, the copper-containing pigment of the present invention having improved properties can be used in various fields where conventional pigments could not be used due to its drawbacks, for example, as an antifouling coating material for organic tin compounds. it can.

Claims (4)

[Claims] 1. A stable copper-containing pigment composition, which is obtained by surface-treating a copper-containing pigment with an organic silicon compound having a reactive group with an inorganic compound. 2. The stable copper-containing pigment composition according to claim 1, wherein the copper-containing pigment is cuprous oxide. 3. The organic silicon compound having a reactive group with an inorganic compound is one or more selected from chlorosilane, alkoxysilane or a silane coupling agent.
Alternatively, the stable copper-containing pigment composition according to claim 2. 4. The stable copper-containing pigment composition according to claim 1, wherein the organosilicon compound having a reactive group with an inorganic compound is at least 0.05% by weight based on the total weight.