JPH01228537A - Dispersion of fine particle - Google Patents

Abstract

PURPOSE:To increase dispersion stability of fine particles in an organic solvent by adding 12-hydroxystearic acid, polyhydric alcohol and benzaldehyde to an organic solvent of a viscosity not lower than 10cp at room temperature, wherein fine particles are dispersed. CONSTITUTION:A dispersion liquid of fine particles is prepared by adding at least one species of gelling agent selected from a group composed of a mixture of 12-hydroxystearic acid, polyhydric alcohol and benzaldehyde, an amine salt of N-acylamino acid, an amide of N-acylamino acid, an ester of N-acylamino acid, to an organic solvent of a viscosity not lower than 10cp at room temperature, wherein fine particles are dispersed. As for the fine particles, preferably having an average grain size of 10mum or smaller, and silicon dioxide, titanium oxide, talc, etc., are usable. As for the organic solvent of a viscosity not lower than 10cp at room temperature, soybean oil, coconut oil, linseed oil, whale oil, liquid paraffin, etc., are available.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to fine particles, and particularly to a method for dispersing fine particles by incorporating an oil gelling agent as an essential component as a dispersant for fine particles in an organic medium. Regarding the method.

[Conventional technology]

Conventionally, methods for dispersing fine particles include l) reducing the diameter of the fine particles; 2) Reduce the density difference between the organic medium and the fine particles. 3) Increase the viscosity of the organic medium. 4) Examples include using a dispersant. When the fine particles and organic medium are selected according to the purpose, the diameter of the fine particles, the density difference between the two, and the viscosity of the organic medium are inevitably determined. Therefore, the selection of an appropriate dispersant is a major point in determining the quality of dispersion. Traditionally, surfactants, surface modifiers, coupling agents, etc. have been used as dispersants, but the appropriate dispersant varies depending on the combination of fine particles and organic medium, and there is no universally applicable dispersant.
The reality is that an appropriate dispersant must be selected for each case, and there is a desire to develop a simple and versatile dispersion method.

[Problem that the invention seeks to solve]

The above-mentioned surfactants, surface modifiers, coupling agents, etc. are appropriate dispersants and are easy to use, but depending on the selection of the fine particles and organic medium used, the shape, particle distribution, and ratio of the fine particles may vary. Physical properties such as surface area and surface potential, chemical properties such as surface acidity/basicity, and functional groups are different, and solubility in organic media is also different.
It is necessary to select an appropriate dispersant, which has the drawback of poor versatility.

[Means for solving problems]

In view of the above circumstances, the present inventors conducted intensive research and completed the present invention by blending an oil gelling agent as a dispersant for fine particles in an organic medium with a diameter of 10 centivoise (cP) or more at room temperature. .

The fine particles according to the present invention preferably have an average particle size of 10 μm or less, and include oxides such as silicon dioxide, titanium white, antimony trioxide, and alumina, carbonates such as calcium carbonate, barium carbonate, and magnesium carbonate, and sulfuric acids such as barium sulfate and calcium sulfate. salts, phosphates such as calcium phosphate, iron phosphate,
Silicates such as talc and kaolin, hydroxides such as hydrogen 1 hyaluminum and magnesium hydride, new ceramics such as synthetic quartz, silicon nitride, silicon carbide, tungsten carbide, and barium titanate are inorganic compounds, and stearic acid Metal soaps such as dumbbell, calcium stearate, aluminum octylate, tetrabromobisphenol A
, bromine compounds such as decabromodiphenyl ether, N
Amino acid compounds such as a-lauroyl lysine and N-lauroyl aspartic acid-β-lauryl ester, polymer compounds such as nylon powder, polystyrene powder, cellulose and cellulose derivative powder, etc. are used as the organic compound.

The organic medium may have a viscosity of 10 centiboise or more at room temperature, and may include animal and vegetable oils such as soybean oil, coconut oil, linseed oil, and whale oil, plasticizers such as dioctyl phthalate, tricresyl phosphate, and chlorinated paraffin, liquid paraffin, Hydrocarbons such as turbine oil, polymer compounds such as polybutadiene, epoxy resins, urethane resins, unsaturated polyesters, and silicone oils are used. Further, oil gelling agents include 12-hydroxystearic acid, condensates of polyhydric alcohols and benzaldehyde, such as dibenzylidene sorbitol, dibenzylidene xylitol,
N-acylamino acid amine salts, such as N,N'-cicabroyl-shi-lysine laurylamine salt, N-acylamino acid amides, such as N-lauroyl-shi-glutamic acid dibutylamide, N-N'-dilauroyl-shi-lysine Laurylamide, N-acylamino acid ester, such as N,N'-cicabroyl-d-lysine lauryl ester, is used in an amount of 0.01 to 0.5% by weight based on the organic medium. The amount of fine particles added is preferably such that the composition in which the fine particles are added to the organic medium maintains fluidity.

The dispersion method is achieved by heating an organic medium to 80 to 160°C, adding an oil gelling agent, cooling after dissolution, adding fine particles thereto, and mixing.

The method for dispersing fine particles of the present invention maintains a good dispersion state in any combination of fine particles and an organic medium as a dispersion medium, and is a versatile method for dispersing in a wide range of applications.

〔Effect of the invention〕

The dispersion method of the present invention maintains a well-dispersed state of fine particles in any combination of fine particles and an organic medium as a dispersion medium, thereby dispersing paints, composite liquid flame retardants, and vinyl chloride made of these fine particles and an organic medium. It can be quickly applied to liquid blasting compounds such as plastisol, epoxy resin, and unsaturated polyester resin, and its effects are extremely large.

Next, the results of evaluating the dispersibility by the method for dispersing fine particles according to the present invention are shown in Examples, but the present invention is not limited by these Examples.

〔Example〕

Example 1 Dioctyl phthalate (viscosity 10 cP or more) 100 ml
12-hydroxystearic acid (hereinafter abbreviated as HR) 0
．． 1 g was added and heated to 130''C to dissolve it, and at room temperature Ig of decabromodiphenyl ether (average particle size 10 μm or less) was added and mixed with stirring to disperse.

Example 2 HRo was dispersed in the same manner as in Example 1 except that 1 g of HRo was changed to 0.4 g.

Example 3 In Example 1, HR was replaced with N-lauroyl-glutamic acid dibutylamide (oil gelling agent GP-1 manufactured by Ajinomoto Co., Ltd.)
(hereinafter abbreviated as GP-1), and was dispersed in the same manner as in Example 1.

Example 4 In Example 1, decabromodiphenyl ether HR was replaced with talc (average particle size of 10 μm or less), and dispersion was carried out in the same manner as in Example 1.

Example 5 Dioctyl phthalate (viscosity 10 cP or more) 100 ml
Add 05g of GP-1 to the solution, heat to 150'C, dissolve, and add antimony pentoxide (average particle size 10μm) at room temperature.
(below) 0.5g was added and stirred and mixed to disperse.

Example 6 Tricresyl phosphate (viscosity 10 cP or more) 100
ml, add 0.1 g of dibenzylidene sorbitol (Gelol D Shin Nippon Rikaku Co., Ltd., hereinafter abbreviated as DBS),
The mixture was heated to 150''C to dissolve it, and antimony dioxide (average particle size: 10 μm or less) Ig was added at 40°C, mixed with stirring, and dispersed.

Example 7 In Example 3, 100 ml of dioctyl phthalate was replaced with turbine oil (viscosity of 10 cP or more) and dispersed in the same manner as in Example 1.

Example 8 DBSo, 4 to 100 ml of soybean oil (viscosity 10 cP or more)
The mixture was heated to 150°C to dissolve it, and at room temperature 0.5 g of calcium carbonate (average particle size: 10 Jim or less) was added, stirred and mixed, and dispersed.

Example 9 In Example 8, DBS was changed to N,N'-cicabroyl-d-lysine lauroyl ester, and the dispersion was carried out in the same manner as in Example 8.

Comparative Example 1 Example 1 without adding 1 g of HRo in Example 1
It was dispersed in the same way.

Comparative Example 2 In Example 1, HRo, 1g was changed to 1g, and Example 1
It was separated in the same manner as above.

Comparative Example 3 Dioctyl phthalate in Example 1 was replaced with toluene (viscosity of 10 cP or less), and the same procedure as in Example 1 was carried out to disperse the toluene.

Comparative Example 4 Dispersion was carried out in the same manner as in Example 1 except that the talc in Example 1 was changed to one having an average particle size of 10 μm or less.

Comparative Example 5 In Example 1, HR was changed to the sodium salt of β-naphthalene sulfonic acid formaldehyde condensed metal product, and the same procedure as in Example 1 was carried out to disperse the mixture.

Comparative Example 6 In Example 1, HR was changed to vinyltrichlorosilane, and dispersion was carried out in the same manner as in Example 1.

Comparative Example 7 In Example 8, the soybean oil was replaced with acetone (viscosity: 10 cP or less), and dispersion was carried out in the same manner as in Example 1.

Comparative Example 8 In Example 8, the calcium carbonate was changed to one with an average particle size of 10 μm or more, and the same procedure as in Example 1 was used to disperse the calcium carbonate.

Example 10 The compositions obtained in Examples 1 to 8 and Comparative Examples 1 to 8 were placed in test tubes, and the settling properties of the powders were observed with the naked eye to evaluate the dispersibility6.
Next, these observation results are shown in Table 1.

From Table 1, it is clearly seen that the method for dispersing fine particles of the present invention provides good dispersibility.

Table 1 Evaluation of dispersibility ○ Good dispersibility × Poor dispersibility

Claims (1)

[Claims] 12-hydroxystearic acid, a condensate of polyhydric alcohol and benzaldehyde, N
- A method for dispersing fine particles, which comprises using at least one of an acylamino acid amine salt, an N-acylamino acid amide, and an N-acylamino acid ester (hereinafter referred to as an oil gelling agent).