JPH03227371A - Method for dispersing pigment - Google Patents

Abstract

PURPOSE:To disperse a pigment in high storage stability by adding a trialkyl orthoformate and a 1-4C alcohol during or before the dispersion of a pigment, filler, etc., in a vehicle of a polymer containing silyl group. CONSTITUTION:In the process for dispersing a pigment and a filler in a vehicle of a polymer having hydrolyzable group (e.g. polyester or vinyl polymer) and expressed by formula (R<l> and R<2> are H, 1-10C alkyl, acyl or aralkyl; X is alkoxy, acyloxy, aminoxy, etc.; a is 0-2), a trialkyl orthophosphate (e.g. trimethyl orthoformate) and a 1-4C alcohol (preferably methanol) are added to the vehicle during or before the dispersion process. The weight ratio of the orthoformate to the pigment and filler is 1 to <=5, preferably 1 to <=2 and the amount of the alcohol is <=30 pts.wt., preferably <=20 pts.wt. per 100 pts.wt. of the pigment and filler.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for dispersing pigments and fillers in a vehicle.
This relates to a method for dispersing pigments and fillers, which involves adding a specific hydrolyzable ester compound in advance or during dispersion, and particularly when the vehicle is a silyl group-containing compound having a hydrolyzable silyl group at the terminal or side chain. This invention relates to a method for dispersing pigments and fillers that has excellent storage stability in a pigment and filler dispersion state in certain cases.

[Prior Art and Problems to be Solved by the Invention] Various silyl group-containing compounds are known for which the method for dispersing pigments and fillers of the present invention is particularly effective. It is widely used in paints, coatings, adhesives, sealants, and brimers because of its adhesion and moisture, especially atmospheric moisture, which crosslinks at room temperature and forms a cured product with excellent durability. However, such compounds tend to react with trace amounts of water in the storage system during storage and gradually increase in viscosity.Especially when blending pigments and fillers, water contained in these compounds or adsorbed onto the surface Moisture can increase the viscosity and even cause gelation, so improving the storage stability of pigments and fillers in a dispersed state has become a major problem in practice.

[Means and effects for solving the problem] As a result of intensive studies, the inventors have found that when dispersing pigments, fillers, etc. in a vehicle, a specific hydrolyzable ester compound is added in advance or at the time of dispersion. The inventors have discovered that by dispersing fillers, the storage stability of pigments and fillers in a dispersed state can be dramatically improved, leading to the present invention.

That is, the method for dispersing pigments and fillers of the present invention includes pigments,
The filler is represented by the general formula (wherein RR2 is hydrogen or a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group, and an aralkyl group, and X is alkoxy, hydroxy, acyloxy, aminoxy, phenoxy, Polyesters, vinyl polymers, diallyl phthalate polymers, diallyl phthalate polymers, having at least one silyl group in the molecule (a group selected from thioalkoxy, amino groups, a represents an integer of O to 2) When dispersing the copolymer in a vehicle, it is characterized by adding trialkyl orthoformate and an alcohol having 1 to 4 carbon atoms during warming or dispersion.

The trialkyl orthoformate used in the present invention is
It has higher hydrolytic reactivity than hydrolyzable organosilicon compounds and easily reacts with trace amounts of water in the storage system, so it is effective when added in a relatively small amount. Examples of such trialkyl orthoformates include trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, and tributyl orthoformate. The trialkyl orthoformate is used in a weight ratio of 1:5 or less, preferably 1:2 to the pigment and filler.
Used below.

Examples of the alcohol having 1 to 4 carbon atoms used in the present invention include methanol, ethanol, propatool, butanol, and the like. These alcohols having 1 to 4 carbon atoms improve storage stability, and are used in an amount of 30 parts by weight or less, preferably 20 parts by weight or less, per 100 parts by weight of the pigment or filler. Among the alcohols having 1 to 4 carbon atoms, methanol is preferred.

Vehicles useful in the method of the present invention include those having functional groups that are sensitive to moisture, and are particularly useful for compounds having hydrolyzable silyl groups.

Compounds having a hydrolyzable silyl group, which are effective vehicles for the method of the present invention, have the general formula (wherein RR2 is hydrogen or a monovalent group selected from alkyl groups having 1 to 10 carbon atoms, aryl groups, and aralkyl groups). at least one silyl group in the molecule; Examples include silyl group-containing polymers such as polyesters, vinyl polymers, diallyl phthalate polymers, and diallyl phthalate copolymers.

One method for producing these silyl group-containing polymers is to combine an organic polymer having a carbon-carbon double bond at the terminal or side chain with a silicon hydride compound in the presence of a Pt-based catalyst. S iC
It is synthesized by hydrosilylation through the reaction of H2CH~.

A polyester having a carbon-carbon double bond at the terminal or side chain can be obtained, for example, by reacting a terminal hydroxyl group polyester (trade name Desmophen, manufactured by Nippon Polyurethane Co., Ltd.) with acryl chloride in the presence of a base such as sodium hydride. can. Alternatively, by adding a portion of allyl glycidyl ether as a diol component during polyester synthesis, it can be obtained by carrying out a condensation reaction between the dibasic acid and the diol.

On the other hand, it can also be obtained by transesterifying a terminal hydroxyl group polyester and a diallyl ester such as diallyl phthalate in the presence of a transesterification catalyst such as toluenesulfonic acid. Furthermore, it can also be obtained by condensing a dibasic acid and a diol under conditions with an excess of acid components, and adding allyl alcohol during or after the reaction to esterify it. In addition, in the presence of a tertiary or quaternary ammonium salt, an acid anhydride, an epoxy compound, and an allyl type alcohol are reacted to introduce an allyl group at the same time as the molecular weight is controlled by the alcohol. By using this method, a polyester having an allylic olefin group in the molecule can be obtained. A polyester containing a terminal acryloyl (or methacryloyl) group can be obtained by condensation of a diol, a dibasic acid, and acrylic acid (or methacrylic acid) by a known method.

As the diallyl phthalate compound having a carbon-carbon double bond, it is possible to use commercially available compounds containing diallyl phthalate monomers or prepolymers.

A copolymer of diallyl phthalate and acrylic ester or methacrylic ester having a carbon-carbon double bond is polymerized using a polymerization initiator such as an azo compound or peroxide, and by changing the amount of diallyl phthalate used as a copolymerization component. The number of double bonds can be adjusted.

Vinyl polymers having carbon-carbon double bonds include vinyl compounds such as styrene, α-methylstyrene, acrylic acid and its esters, methacrylic acid and its esters, acrylamide, vinyl acetate, ethylene, maleic anhydride, etc. alone or It can be obtained by radical copolymerization of a part of allyl acrylate or allyl methacrylate during production of the copolymer.

Examples of silicon hydride compounds include halogenated silanes such as trichlorosilane, methyldichlorosilane, dimethylchlorosilane, and phenyldichlorosilane; trimethoxysilane, triethoxysilane, methyljethoxysilane,
Alkoxysilanes such as methyldimethoxinelan and phenyldiacetoxinlan; acyloquinesilanes such as methyldimethoxinelan and phenyldiacetoxinlan;
Ketoximate silanes such as bis(dimethylketoximate)methyltonlan and bis(cyclohexylketokymate)methylsilane and 5i-HXSi in one molecule
Examples include organopolysiloxanes having at least one -X bond. When a halogenated silane is used, it is exchanged with another hydrolyzable functional group after hydrosilylation.

Other methods for synthesizing silyl group-containing polymers include combining vinyl group-containing compounds such as vinyltrimethoxysilane, γ-methacryloxytrimethoxysilane, and γ-methacryloxymethyldimethoxysilane with styrene, α
- It can be obtained by copolymerization with vinyl compounds such as methylstyrene, acrylic acid and its esters, methacrylic acid and its esters, acrylamide, vinyl acetate, ethylene, and maleic anhydride.

In addition, epoxy polymers, reactions between organic polymers having epoxy groups such as copolymers of glycidyl methacrylate and vinyl compounds, and γ-aminopropyltrimethoxysilane, polyesters having carboxylic acid groups, organic polymers such as vinyl polymers, etc. Silicon-containing polymers can also be obtained by reaction with γ-glycidoxyprobyltrimethoxysilane.

As the pigments and fillers used in the method of the present invention, those used in general paints, coating agents, adhesives, sealants, brides, etc. are used.

For example, ultramarine, navy blue, zinc yellow, red iron, yellow lead, lead white,
Inorganic pigments such as titanium white, carbon black, transparent iron oxide, and hemium powder; organic pigments such as azo, triphenylmethane, quinoline, anthraquinone, and phthalocyanine;
And applied to fillers such as silica, calcium carbonate, magnesium carbonate, clay, asbestos, mica, talc, graphite, zinc, zinc oxide, calcium oxide, molybdenum sulfide, glass fiber, etc.

The pigments and fillers used in the method of the present invention can be dispersed by methods commonly used for dispersing paints, coating agents, adhesives, sealants, brimers, etc., such as roll milling, ball milling, and sand milling. , high-speed impeller mill method, disperser method, kneader method, etc. can be applied. In the present invention, when dispersing the pigment and filler as shown above in a vehicle, trialkyl orthoformate and an alcohol having 1 to 4 carbon atoms are added to the pigment and filler before dispersing the pigment and filler using the above dispersion method. Pigments and fillers can be stored in a dispersed state by adding trialkyl orthoformate and an alcohol having 1 to 4 carbon atoms and performing a dispersion process. It is possible to obtain highly stable paints, coatings, adhesives, sealants, brimers, etc.

The pigment and filler dispersion obtained according to the present invention forms an excellent resin at room temperature or by heating, and in this case, a curing accelerator may or may not be used. When using a curing accelerator, use carboxylic acid metal salts such as alkyl titanates, tin octylate, dibutyltin dilaurate, and lead octylate, sulfide type organic mercaptide types such as monobutyltin sulfide, dibutyltin dioctyl mercaptide, etc. Tin compounds, acidic catalysts such as p-toluenesulfonic acid and phthalic acid, amines such as tetraethylenepentamine, triethylenediamine, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, potassium hydroxide, sodium hydroxide Alkaline catalysts such as are effective.

Furthermore, the pigment and filler dispersion obtained according to the present invention can be blended with various resins currently used as paints, coating agents, adhesives, sealants, primers, etc. For example, lacquers, etc. It can be used by mixing with acrylic resin, acrylic lacquer resin, thermosetting acrylic resin, alkyd resin, melamine resin, epoxy resin, etc. in an appropriate ratio, and improves the adhesion to the substrate and the resulting coating film. Physical properties such as weather resistance can be improved.

[Examples] Next, the present invention will be specifically described with reference to Examples and Comparative Examples.

Production Example 1 148g phthalic anhydride, 46.4g propylene oxide, 22.8g allyl glycidyl ether, 11
．． 6g of allyl alcohol and 0.5g of dimethylbenzylamine were placed in a 1P metal autoclave at 100°C.
After 3 hours, 46 g of propylene oxide was added and the reaction was continued for another 1 hour. After that, excess propylene oxide was removed to obtain a polyester having a molecular weight of 1200. 9.5 g of acetic anhydride is added to 1 oog of the obtained polyester and reacted at 120° C. for 2 hours, and then excess acetic anhydride is removed under reduced pressure to treat the hydroxyl groups in the polyester.

22.2g of hydroxyl-treated polyester, 0 chloroplatinic acid
゜0035g, 8.65g of methyldichlorosilane
C. for 3 hours, and then excess methyldichlorosilane was removed under reduced pressure. After the reaction, 20 mg of methanol and 20 m, p of methyl orthoformate were added, stirred at room temperature for 1 hour, and low-boiling substances were removed under reduced pressure to obtain a silyl group-containing polyester.

Production Example 2 Diallyl phthalate prepolymer (trade name: Datsutsushi, manufactured by Osaka Soda Co., Ltd., iodine value: 80) 100 g, chloroplatinic acid 0
．． 00001g and 1g of hydroquinone were dissolved in 100ml of toluene.

35 mfi of methyljethoxysilane was added to this solution and reacted at 90° C. for 3 hours to obtain a silyl group-containing diallylphthalate prepolymer.

Production Example 3 In a solvent of 100 g of toluene heated to 90°C, 30 g of styrene, 16 g of allyl methacrylate, 20 g of methyl methacrylate, 19 g of n-butyl methacrylate, 14 g of butyl acrylate, 2 g of maleic anhydride, 2 g of Sn-dodecyl mercaptan, and 2 g of azo Bisisobutyronitrile 2
A solution of f is added dropwise and reacted for 10 hours to form a molecule f.
An allylic unsaturated group-containing vinyl polymer having a fi of 8000 was obtained. The infrared absorption spectrum of this substance has 1648
cm-' absorption due to carbon-carbon double bonds was observed.

Obtained allylic unsaturated group-containing vinyl copolymer solution 2
0g to 1.5g trimethoxysilane.

A solution of 0.0005 g of chloroplatinic acid dissolved in isopropanol was added, and the mixture was reacted at 90° C. for 6 hours under sealed conditions. In the infrared absorption spectrum of this product, the absorption of 1648(to)-1 disappeared, and a silyl group-containing vinyl polymer was obtained.

Production Example 4 A reaction was carried out in the same manner as in Production Example 3 except that 31 g of diallyl phthalate was used in place of 16 g of allyl methacrylate in Production Example 3 to obtain a silyl group-containing diallyl phthalate polymer.

Production Example 5 In 100 g of toluene solvent heated to 100°C, 30 g of styrene, 27 g of γ-methacryloxypropyltrimethoxysilane, 20 g of methyl methacrylate, 9 g of n-butyl methacrylate, 14 g of butyl acrylate, 1 g of maleic anhydride, and n-dodecyl mercaptan. Add dropwise a solution of 2g of azobisisobutyronitrile to 2g of
The reaction was carried out for 0 hours to obtain a silyl group-containing vinyl polymer having a molecular weight of 9,000.

Production Example 6 Styrene 30 was added to 70 g of xylene heated to 90°C.
g 1CH-C(CHs) COO(CH) Si
(OCH3) 322g1 meth3 Methyl acrylate 22g1 n-butyl methacrylate-5g
1 Butyl acrylate 18g 1 Acrylamide 4g 5n-
A solution of 2 g of azobisisobutyronitrile dissolved in 10 g of butanol was added dropwise and reacted for 10 hours.
A vinyl resin containing 4,000 silyl groups was obtained.

Example 1.2 and Comparative Examples 1 to 1] The silyl group-containing compounds obtained in Production Examples 1 to 6 were treated and dispersed with the pigments and fillers shown in Table 1, and the resulting pigment and filler dispersion The product was diluted to an appropriate viscosity, and its storage stability at 50°C in a sealed state was examined. As a comparative example,
The storage stability when a hydrolyzable ester compound is added after dispersing the pigment and filler is also shown.

As shown in Table 1, by adding trialkyl orthoformate and an alcohol having 1 to 4 carbon atoms before or during pigment dispersion, the storage stability of the pigment in the dispersed state is greatly improved.

[Effects of the invention] As described above, when dispersing pigments, fillers, etc. in a vehicle of a silyl group-containing polymer, trialkyl orthoformate and an alcohol having 1 to 4 carbon atoms are added in advance or at the time of dispersion. By dispersing the filler, the storage stability of the pigment and filler dispersed state is dramatically improved.

Claims (1)

[Claims] 1. When dispersing pigments and fillers in a vehicle which is a silyl group-containing polymer represented by the following general formula, trialkyl orthoformate and a carbon number of 1 to 4 are added in advance or during dispersion.
A method for dispersing pigments and fillers, which comprises adding alcohol. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R^1 and R^2 are hydrogen or a monovalent hydrocarbon group selected from alkyl groups having 1 to 10 carbon atoms, aryl groups, and aralkyl groups, and X is A polyester or vinyl polymer having at least one silyl group in the molecule selected from alkoxy, hydroxy, acyloxy, aminoxy, phenoxy, thioalkoxy, and amino groups, where a represents an integer of 0 to 2. , diallyl phthalate polymer, diallyl phthalate copolymer.