JPH0214097B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a novel dispersant for stably dispersing various solid particles in a liquid medium, and a dispersion using the dispersant. (Conventional technology) Conventionally, various organic pigments, inorganic pigments, extender pigments,
Since it is difficult to stably disperse various solid particles such as fillers and magnetic particles in a liquid medium, various dispersants are used to disperse these solid particles. Most conventional dispersants activate the surface of the solid particles to be dispersed to improve wetting by a liquid medium. Various types of activators have been proposed, ranging from those with medium molecular weights to those with high molecular weights. (Problem to be Solved by the Invention) In order to prepare printing inks and paints by dispersing solid particles in a liquid medium using conventional dispersants such as those described above, it is necessary to apply these printing inks and paints to a substrate. After that, various binder resins are included in the dispersion liquid in order to fix the solid particles contained in the dispersion liquid to the substrate, but conventional dispersants are not compatible with these binder resins. For example, after the coating film is formed, these dispersants may adversely affect various physical properties of the formed coating film, resulting in various problems such as bleeding of the dispersant, decrease in coating strength, and damage to the coating film. This causes the surface to become sticky. These various problems can be solved by using the same type of dispersant as the binder resin, but using the same type of dispersant as the binder resin does not improve versatility. If the binder resin is chipped or the binder resin is changed, the dispersion stability of the obtained dispersion liquid cannot be achieved.On the other hand, a dispersant with good dispersion stability always causes various troubles as mentioned above. The present inventor solved the problems of the prior art as described above, and while maintaining high dispersion stability of the dispersion,
As a result of intensive research to obtain a dispersant that does not cause the various troubles mentioned above, when preparing a dispersant from a certain material, the obtained dispersant is an excellent dispersant that solves the various problems mentioned above. The present invention was completed based on this finding. (Means for Solving the Problems) That is, the present invention provides a dispersant comprising a reaction product of a silane coupling agent having a reactive organic functional group and an organic polyisocyanate, and the dispersant. This is the dispersion liquid used. To explain the present invention in more detail, the dispersant used in the present invention and which primarily characterizes the present invention is a reaction product of a silane coupling agent having a reactive organic functional group and an organic polyisocyanate. The silane coupling agent having a reactive organic functional group used to obtain such a dispersant is a compound represented by the general formula X-R-Y (). X in the above general formula () is a group capable of reacting with an isocyanate group, such as an amino group, an epoxy group, a hydroxyl group, a thiol group, a carboxyl group, etc., and particularly preferable ones are an amino group, an epoxy group, and a thiol group. It is. Further, R in the general formula () is any divalent organic group, preferably having 2 to 20 carbon atoms.
an aliphatic group, an aromatic group, an aliphatic group,
These groups contain an oxygen atom as a linking group,
It can contain nitrogen atoms and sulfur atoms. In addition, Y in the general formula () is Si(R)m(R')
n (R is H or a C ₁ to C ₄ alkyl group,
R' is a _C1 - _C4 alkoxy group, m is 1-2,
n is 2-3. ). Preferred compounds of the general formula () are as follows:
Some examples are as follows. The silane coupling agents having a reactive organic functional group as described above are examples of silane coupling agents preferable in the present invention, and the present invention is not limited to these examples. Other compounds represented by the general formula () are currently commercially available and can be easily obtained from the market, and any of them can be used in the present invention. The organic polyisocyanate used in the present invention and which is the second characteristic of the present invention is a compound having at least two isocyanate groups in an aliphatic or aromatic compound, and has been widely used as a raw material for polyurethane synthesis. has been done. Any of these known organic polyisocyanates are useful in the present invention. Particularly preferred organic polyisocyanates are as follows. Toluene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-isopropyl-1,3-phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4-butoxy-1, 3-phenylene diisocyanate, 2,4-diisocyanate-diphenyl ether, mesitylene diisocyanate, 4,4-methylenebis(phenyl isocyanate), diylylene diisocyanate, 1,5-naphthalene diisocyanate, benzidine diisocyanate, o-nitrobenzidine diisocyanate , 4,4-dibenzyl diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-tetramethylene diisocyanate, 1,10-decamethylene diisocyanate, 1,4-cyclohexylene diisocyanate, xylylene diisocyanate, 4,4-methylene bis (cyclohexyl isocyanate), 1,5-tetrahydronaphthalene diisocyanate, and adducts of these organic polyisocyanates with other compounds, such as Furthermore, urethane prepolymers having two or more isocyanate groups at the ends. The dispersant of the present invention combines a silane coupling agent having a reactive organic functional group as described above and an organic polyisocyanate as described above, such that the reactive organic functional group and the isocyanate group are in a functional ratio of about 1:1. It can be easily obtained by reacting at a temperature of about 0 to 100°C, preferably 20 to 50°C, for about 10 minutes to 3 hours in the presence or absence of an organic solvent and a catalyst. . The organic solvent that may be used in the production of such a dispersant may be any organic solvent as long as it is inert to the respective reaction raw materials and products. For example, preferred organic solvents include methyl ethyl ketone, methyl- n-propyl ketone, methyl isobutyl ketone, diethyl ketone, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, butyl acetate, acetone, cyclohexane, tetrahydrofuran, dioxane, methanol, ethanol, isopropyl alcohol, butanol, methyl cellosolve, butyl cellosolve,
cellosolve acetate, dimethylformamide,
Dimethyl sulfoxide, pentane, hexane, cyclohexane, heptane, octane, mineral spirits, petroleum ether, gasoline, benzene,
Examples include toluene, xylene, chloroform, carbon tetrachloride, chlorobenzene, perchloroethylene, trichlorethylene, and the like. When the dispersant of the present invention obtained as described above is produced using an organic solvent, it may be separated from the organic solvent, or it may be used as a solution of the organic solvent. The dispersant of the present invention separated from the organic solvent is generally in the form of a white to brown liquid or solid, and is easily soluble in organic solvents used to disperse various solid particles. According to various analyzes such as infrared absorption spectroscopy, elemental analysis, and molecular weight measurement, the dispersant of the present invention as described above shows that the isocyanate group of the organic polyisocyanate and the reactive organic functional group of the silane coupling agent are It has become clear that when an addition reaction occurs, for example, when the reactive organic functional group is an amino group, the two are bonded together through an -NHCONH- bond. According to the inventor's detailed research, the dispersant of the present invention can extremely easily and stably disperse various solid particles when dispersing them in a liquid medium containing a binder resin. It does not cause gelation, thickening, or coagulation and sedimentation of solid particles even when stored for a long period of time, and the resulting dispersion can be applied to a substrate as various printing inks or paints and dried to form a coating film. However, unlike conventional dispersions, it does not bleed onto the coating film surface or reduce the strength of the coating film, and furthermore, it does not impair the electrical, chemical, and physical properties of the coating film, but rather improves them. This is what we found out. Therefore, the dispersant of the present invention is extremely useful as a dispersant for dispersing various organic dyes and pigments, inorganic pigments, extender pigments, fillers, magnetic particles, and other solid particles in a liquid medium. To explain the second aspect of the present invention, the second aspect of the present invention relates to a dispersion using the above-mentioned dispersant of the present invention. The dispersion liquid of the present invention includes the above-mentioned dispersant of the present invention, solid particles, binder resin, and liquid medium as essential components. As the solid particles used in the second aspect of the present invention, any conventionally known organic dyes and pigments, inorganic pigments, extender pigments, fillers, magnetic particles, and other solid particles can be used. Examples include azo-based, phthalocyanine-based, quinacridone-based, indigo-based, thioindigo-based, anthraquinone-based, perylene/perinone-based, dioxazine-based, and other organic pigments and dyes. Inorganic pigments include iron oxide, lead chromate,
Titanium oxide type, zinc oxide type, other metal oxide type, composite metal oxide type, cadmium sulfide type, dark blue,
Examples include ultramarine, carbon black, and other inorganic pigments. Examples of extender pigments and fillers include silica-based, alumina-based, metal carbonate-based, metal sulfate-based, clay, talc, and other various extender pigments and fillers. Examples of magnetic particles include iron, chromium, nickel, cobalt, alloys or oxides thereof, and modified products thereof, specifically, for example, γ-Fe ₂ O ₃ , ferrite, magnetite, CrO ₂ , cobalt-doped γ-Fe ₂ O ₃ ,
Examples include a cobalt-doped bertolide compound of Fe ₂ O ₃ and Fe ₃ O ₄ . The solid particles described above are merely examples, and
Of course, various types of solid particles other than those exemplified above can also be used in the present invention, and can be used alone or as a mixture. In the present invention, binder resins used include various binder resins conventionally used in printing inks and paints, and any of these binder resins can be used. resins, vinyl chloride/vinyl acetate/vinyl alcohol copolymer resins, alkyd resins, epoxy resins, acrylonitrile-butadiene resins, polyurethane resins, nitrocellulose resins, polybutyral resins,
Examples include polyester resins, silicone resins, melamine resins, urea resins, acrylic resins, and polyamide resins. These resins can be used alone or as a mixture, and can be used as a solution or dispersion in an organic solvent. The liquid medium used in the present invention is the organic solvent used in the preparation of the dispersant described above or a mixture thereof. The dispersion of the present invention has the above-mentioned components as essential components, and their usage ratios are the same as in conventional dispersions, such as printing inks and paints.
For example, if the entire dispersion is 100 parts by weight, the solid particles account for about 10 to 50 weight %, the dispersant accounts for about 5 to 20 weight % of these solid particles, and the liquid medium accounts for about 10 to 50 weight %. Approximately 30-50% by weight, and the binder resin is approximately 10-50% by weight.
A range of 50% by weight is common. As long as the dispersion liquid of the present invention contains these components as essential components, other subcomponents other than those mentioned above, such as plasticizers, antistatic agents, surfactants, lubricants, crosslinking agents,
Optional additives such as anti-aging agents, stabilizers, blowing agents, and antifoaming agents may be included. The method for producing the dispersion of the present invention comprising the above-mentioned essential components and optional components may be any conventionally known method, and generally, while adding the necessary components simultaneously or sequentially, ball milling, mixer treatment, Mixing and dispersing grinding methods such as roll milling, bead milling, gravel milling, sand milling, and high-speed impeller processing are suitable. The conditions for this dispersion method itself vary depending on the type and size of the solid particles to be dispersed, their purpose, etc., but generally they are carried out at a temperature between room temperature and 100°C.
It is sufficient to process for about 5 minutes to 20 hours. The dispersion of the present invention obtained as described above is useful for various purposes, such as printing inks, paints, various coating agents, various surface treatment agents, various impregnating agents, adhesives, etc., like conventional dispersions. , and its uses are not limited. (Action/Effect) The dispersant of the present invention has an excellent dispersion effect when dispersing solid particles suitable for the above-mentioned uses in a solvent medium, so that the preparation of a dispersion liquid is easy. In addition, the dispersant of the present invention is easily soluble in various organic solvents when dispersing solid particles, and is also excellently compatible with any binder resin in the solvent, so it is easy to use when dispersing solid particles. It does not thicken or gel the binder resin solution. Furthermore, the dispersion of the obtained dispersion of the present invention has high dispersion stability, and no coagulation, sedimentation, etc. of solid particles are observed even when stored for a long period of time before use, and even when the ambient temperature changes dramatically during that time. . Furthermore, the greatest advantage is that when the dispersion of the present invention is used in various applications and the liquid medium is removed by evaporation to form a coating film, the contained dispersant of the present invention is removed from the coating film consisting of the binder resin. The point is that it does not cause any deterioration in the physical, chemical, or electrical properties of the coating film surface or the coating film itself due to bleeding or separation. Therefore, by using the dispersant and dispersion liquid of the present invention, the various drawbacks of the prior art mentioned above are fully solved. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Note that "%" or "%" in the text is based on weight. Example 1 875 parts of an adduct of 1 mole of trimethylolpropane and 3 moles of tolylene diisocyanate (TDI) (Coronate L, manufactured by Nippon Polyurethane, NCO% 12.5, solid content 75%) was stirred well at room temperature.
In this, 3-aminopropyltriethoxysilane
Gradually add 663 parts to react. After the reaction was completed, ethyl acetate was evaporated to obtain 1300 parts of the dispersant of the present invention in the form of a white solid. According to the infrared absorption spectrum of this dispersant,
The absorption due to free isocyanate groups at 2270/cm disappeared, and an absorption band due to Si-O-C groups appeared at 1090/cm. In addition, as for the molecular weight measurement result by the freezing point depression method, the theoretical value was 1319, but the actual value was 1305, which was in good agreement with the theoretical value. Therefore, the main structure of the above-mentioned dispersant of the present invention is estimated to be the following formula. Example 2 Adduct of hexamethylene diisocyanate and water (Dyuranate 24A-100, manufactured by Asahi Kasei, NCO%
23.5) Add 186 parts of 3-aminopropyltriethoxysilane to 150 parts of 3-aminopropyltriethoxysilane while stirring well at room temperature.
330 parts of a colorless and transparent liquid dispersant of the present invention was obtained. According to the infrared absorption spectrum of this dispersant,
The absorption due to free isocyanate groups at 2270/cm disappeared, and an absorption band due to Si-O-C groups appeared at 1090/cm. Therefore, the main structure of the above-mentioned dispersant of the present invention is estimated to be the following formula. Example 3 Adduct of 1 mol of trimethylolpropane and 3 mol of xylylene diisocyanate (takenate
D110N, Takeda Pharmaceutical, NCO% 11.5, solid content 75%)
Stir 150 parts at room temperature and add 3 parts to it.
- Gradually add 81 parts of mercaptopropyltrimethoxysilane dropwise to react. After the reaction was completed, ethyl acetate was evaporated to obtain 225 parts of the dispersant of the present invention in the form of a white solid. According to the infrared absorption spectrum of this dispersant,
The absorption due to free isocyanate groups at 2270/cm disappeared, and an absorption band due to Si-O-C groups appeared at 1090/cm. Therefore, the main structure of the above-mentioned dispersant of the present invention is estimated to be the following formula. Example 4 3-glycidoxypropyltrimethoxysilane
A mixture obtained by reacting 708 parts with 387 parts of dibutylamine is gradually added dropwise to 875 parts of an adduct (Coronate L) of 1 mol of trimethylolpropane and 3 mol of tolylene diisocyanate (Coronate L) at room temperature while stirring well. After the reaction was completed, ethyl acetate was evaporated to obtain 1740 parts of the dispersant of the present invention in the form of a white solid. According to the infrared absorption spectrum of this dispersant,
The absorption due to free isocyanate groups at 2270/cm disappeared, and an absorption band due to Si-O-C groups appeared at 1090/cm. Therefore, the main structure of the above-mentioned dispersant of the present invention is estimated to be the following formula. Example 5 442 parts of 3-aminopropyltriethoxysilane is dissolved in methyl ethyl ketone, and while stirring well at room temperature, 262 parts of 4,4'-methylenebis(cyclohexyl isocyanate) is gradually added dropwise to react. After the reaction was completed, ethyl acetate was evaporated to obtain 695 parts of the liquid dispersant of the present invention. According to the infrared absorption spectrum of this dispersant,
The absorption due to free isocyanate groups at 2270/cm disappeared, and an absorption band due to Si-O-C groups appeared at 1090/cm. In addition, as for the molecular weight measurement result by the freezing point depression method, the theoretical value was 704, whereas the actual value was 701, which was in good agreement with the theoretical value. Therefore, the main structure of the above-mentioned dispersant of the present invention is estimated to be the following formula. Example 6 150 parts of polybutylene adipate with a molecular weight of 2000 having a hydroxyl group at the end, 20 parts of 1,4-butanediol
52 parts of tolylene diisocyanate were subjected to an addition reaction in 412 parts of tetrahydrofuran (solid content 35%),
A polyurethane resin solution with a viscosity of 50 poise/20°C was obtained. To 100 parts of this polyurethane resin solution, 7 parts of the dispersants obtained in Examples 1 to 5 and 33 parts of petroleum fraction having a boiling point of 100 to 120°C were added and mixed well. 30 parts of this resin solution and 30 parts of 1-amino-2-phenoxy-4-hydroxyanthraquinone, boiling point
A mixture consisting of 40 parts of petroleum fractions at 100-120°C was processed in a ball mill for 20 hours to obtain a dispersion of the present invention. It was fluid and suitable for use in dyeing polyester fibers from organic solvents and in gravure and rotary screen printing inks for printing paper.

[Table] Reference example 1 Add 3-aminopropyltriethoxy to 100 parts of a polyurethane resin solution (solid content 35%) obtained from polybutylene adipate with a molecular weight of 2000 having a hydroxyl group at the end, 1,4-butanediol, and tolylene diisocyanate. A solution of 7 parts of silane and 33 parts of petroleum fraction was blended with pigment in the same manner as in Example 5, and ball milled for 20 hours. The resulting dispersion had good dispersibility and fluidity, but after transfer drying, a large amount of bubbling, presumably from 3-aminopropyltriethoxysilane, appeared, making it unsuitable for practical use. Example 7 30 parts of butyral resin (Eslec B, BL-2, manufactured by Sekisui Chemical) was dissolved in 70 parts of tetrahydrofuran, and 7 parts of the dispersant obtained in Examples 1 to 5 and a boiling point of 100
16 parts of petroleum fraction at ~120°C were mixed well. A mixture of 30 parts of this dispersant resin solution, 30 parts of polychlorocopper phthalocyanine, and 40 parts of petroleum fraction having a boiling point of 100 to 120°C was processed in a ball mill for 20 hours to obtain a dispersion of the present invention. This was suitable for use in gravure printing inks. Reference example 2 In 100 parts of butyral resin solution (solid content 30%),
3-glycidoxypropyltrimethoxysilane 7
A solution of 16 parts of petroleum fraction and 16 parts of petroleum fraction was mixed with pigment in the same manner as in Example 6, and subjected to ball milling for 20 hours. The resulting dispersion had good dispersibility and fluidity, but after the transfer drying, a large amount of bubbling, presumably from 3-glycidoxypropyltrimethoxysilane, appeared, making it unsuitable for practical use. Example 8 150 parts of polybutylene adipate with a molecular weight of 2000 having a hydroxyl group at the end, 20 parts of 1,3-butylene glycol, and 52 parts of tolylene diisocyanate were subjected to an addition reaction in 412 parts of methyl ethyl ketone (solid content 35%), and the viscosity was 300 poise. /20°C polyurethane resin solution was obtained. To 100 parts of this polyurethane resin solution,
7 parts of the dispersant obtained in Examples 1 to 5 and 13 parts of methyl ethyl ketone were added and mixed well. r-Fe ₂ O ₃ 100 parts The above polyurethane (35% solution) 85 parts Dispersant (lecithin) 2 parts Carbon black 2 parts Methyl ethyl ketone 67 parts Toluene 67 parts Cyclohexanone 67 parts The above ingredients were mixed and kneaded in a ball mill for 50 hours. Further, 8 parts of Coronate L was added and kneaded for a further 3 hours, and the kneaded product was passed through a filter to obtain a dispersion of the present invention. Reference Example 3 7 parts of 3-aminopropyltriethoxysilane and 13 parts of methyl ethyl ketone were added to 100 parts of the polyurethane resin solution obtained in Example 8 (solid content 35%), a magnetic material was added in the same manner as in Example 8, and the mixture was milled in a ball mill. Processing was carried out. After kneading, when 8 parts of Coronate L was added and further kneaded, this dispersion significantly thickened and was unusable. Reference Example 4 In place of 3-aminopropyltriethoxysilane in Reference Example 3, 3-glycidoxypropyltrimethoxysilane was used to obtain a dispersion. Test Example 1 The dispersions obtained in Examples 1 to 5 and Reference Examples 3 to 4 were coated onto a polyester film using a reverse roll coater to a thickness of 20μ, dried at room temperature for 2 hours, and then heated at 80°C. A coating film was obtained by heating and drying in an oven for 24 hours. In order to examine the dispersibility of solid particles, the surface gloss of the coating film was measured using a variable angle gloss meter (Toyo Rika Kogyo) in accordance with JISZ8741. As shown below, the results showed that the better the dispersibility, the better the gloss.

[Table] Lead

Claims (1)

[Scope of Claims] 1. A dispersant comprising a reaction product of a silane coupling agent having a reactive organic functional group and an organic polyisocyanate. 2. The dispersant according to claim 1, wherein the reactive organic functional group of the silane coupling agent is a group capable of reacting with an isocyanate group. 3. A dispersion liquid characterized by comprising a dispersant made of a reaction product of a silane coupling agent having a reactive organic functional group and an organic polyisocyanate, solid particles, and a liquid medium. 4. The dispersion according to claim 3, wherein the reactive organic functional group of the silane coupling agent is a group capable of reacting with an isocyanate group. 5. The dispersion liquid according to claim 3, wherein the dispersion liquid is a printing ink or a paint.