JPH0431471A - Pigment dispersant - Google Patents

Abstract

PURPOSE:To obtain a pigment dispersant which does not precipitate in a coating material even at low temperature by reacting a polyalkylenepolyamine compound, a ring-opening copolymer of a monoalcohol, a monoepoxy compound and a lactone compound, and a specified polymer compound. CONSTITUTION:A pigment dispersant comprising a product obtained by reacting a polyalkylenepolyamine compound (A) having at least one active hydrogen atom in the molecule and a number-average molecular weight of 60-20000 with an isocyanate-terminated polymer compound (B) having a number-average molecular weight of 500-10000 and obtained by reacting a ring-opening copolymer of a monoalcohol of formula I (wherein R1 is a 1-24C linear, branched, alicyclic or aromatic hydrocarbon group), a monoepoxy compound of any one of formulas II-IV and a lactone compound of formula V (wherein R3 is 1-20C alkylene) with a diisocyanate compound of formula VI (wherein R4 is a 4-20C linear, branched, alicyclic or aromatic hydrocarbon group) in a molar ratio of component A to component B of 1:1-1:20.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a pigment dispersant used when mixed with a coating composition in the manufacture of paints.

(Prior art) In recent years, pigment dispersants in which polyamine compounds are combined with polyester resins or acrylic resins have attracted attention for the purpose of pigment dispersion and prevention of pigment aggregation in paint manufacturing, and significant improvements in pigment dispersibility have been achieved. ing.

The organic amine compound is an adsorption point to the pigment, a so-called anchor group, and the polyester resin or acrylic resin is a part that becomes a protective layer that sterically prevents aggregation between pigments, and acts as a so-called barrier group. It is important that the barrier group has an affinity with the resin of the paint.

Such pigment dispersants are disclosed in JP-A-61-174939, JP-A-60-166318, and JP-A-46-7294.
JP-A No. 60-147224 and the like are known.

(Problems to be Solved by the Invention) Among these, the pigment dispersants known in JP-A-61-174939 and JP-A-60-147224 can improve the dispersibility of pigments, but the dispersants The dispersant itself has crystallinity, and in cold regions, the dispersant precipitates in the paint, which has the disadvantage of impairing the appearance of the paint film.

Also, JP-A-6O-I66318 and JP-A-46-
The pigment dispersant known in Publication No. 7294 improves the dispersibility of pigments, but there are restrictions on the resins that can be used in paints, and there is a drawback that improvement in dispersibility cannot be seen with a wide range of resins. This remains an issue to be addressed.

(Means for Solving the Problems) As a result of intensive studies to solve the above problems, the present inventors found that the dispersant does not have crystallinity and therefore precipitates in the paint even at low temperatures. As a result, we have discovered a pigment dispersant that can be used with an extremely wide range of resins without impairing the appearance of the coating film, and have completed the present invention.

Such a dispersant of the present invention has the following A component: a polyalkylene polyamine compound having one or more active hydrogen atoms per molecule and a number average molecular weight of 60 to 20,000, and the following B component: the following formula % formula % (1) (R1 in the formula represents a linear, branched, alicyclic or aromatic hydrocarbon group having 1 to 24 carbon atoms), and a monohydric alcohol represented by the following formula % Formula % (2) (In the formula, R1 is the same as above, and R2 is a hydrogen atom or a linear, branched, alicyclic, or aromatic hydrocarbon group having 1 to 24 carbon atoms. ) and a monoepoxy compound represented by the following formula (R3 in the formula represents an alkylene group having 1 to 20 carbon atoms)
A ring-opened copolymer with a lactone compound represented by A number average molecular weight of 500 to 10.000 that has an isocyanate group at the molecular end by reaction with a diisocyanate compound represented by (representing a hydrocarbon group)
The molar ratio of component A and component B is 1=
1 to 1:20.

The pigment dispersant will be explained in detail below.

Component A of the present invention is a polyalkylene polyamine compound having one or more active hydrogen atoms per molecule and having a number average molecular weight of 60 to 20,000. This polyalkylene polyamine compound is a component containing a nitrogen atom that serves as an adsorption point to a pigment, and should be understood as a general term for amine compounds consisting of a nitrogen atom and an alkyl group.

Polyalkylene polyamines that are industrially easily available include polyethyleneimines, which are ring-opening polymers of ethyleneimine, dihalogen compounds of saturated hydrocarbons having 1 to 8 carbon atoms and ammonia, and saturated hydrocarbons having 1 to 8 carbon atoms. Good examples include a wide variety of polyalkylene polyamines obtained by dehydrochlorination reaction with organic amines having hydrocarbons.

Polyalkylene polyamine compounds may have any structure such as linear, branched, cyclic, etc.
It is necessary to have a number average molecular weight of .

When the number average molecular weight is less than 60, the adsorption power to the pigment becomes weak and sufficient pigment dispersibility cannot be obtained.

Moreover, when it exceeds 20,000, the affinity with the coating resin decreases and the dispersibility also decreases.

Component B is a -hydric alcohol of formula (1) and formulas (2) to (
A ring-opening copolymer (polyester compound) obtained by ring-opening copolymerization of the monoepoxy compound of 4) and the lactone compound (cyclic ester compound) of formula (5) is reacted with the diisocyanate compound of formula (6). obtained by
Has an isocyanate group at the end of the molecule and has a number average molecular weight of 5.
00-10.000 polymer compound.

Component B has a number average molecular weight of <500 to 10.000 as described above, and if the number average molecular weight is less than 500, a sufficient steric repulsion layer will not be formed and pigment dispersibility will deteriorate. If it exceeds 10.000, the pigment dispersant is likely to be detached from the pigment surface, resulting in a decrease in pigment dispersibility.

The ring-opening copolymerization of the above-mentioned alcohol, monoepoxy compound, and lactone compound is anionic polymerization using a catalyst such as lithium, lithium hydride, potassium hydroxide, sodium alcoholade, or tertiary amines, triethylaluminum, triethyl This can be carried out by methods such as coordination anionic polymerization using a catalyst such as tin, or cationic polymerization using a catalyst such as aluminum chloride, toluenesulfonic acid, or phosphoric acid.

The molar ratio of the monoepoxy compound to the lactone compound during ring-opening polymerization is preferably 1/9 to 9/1. If the molar ratio of the monoepoxy compound is less than 1/9, the crystallinity of component B itself will be significant, and the pigment dispersant using this component B will also have crystallinity. For this reason, in paints using pigment dispersants, the pigment dispersants precipitate at low temperatures, impairing the appearance of the paint film.

On the other hand, if the molar ratio of the monoepoxy compound exceeds 9/1, the pigment dispersant will contain a large amount of ether groups, resulting in poor water resistance of the coating film. In addition, the compatibility with a wide range of resins decreases, so that the features of the present invention cannot be fully expected.

The pigment dispersant of the present invention has the above-mentioned A component and B component of 1:
They are reacted and bonded in the following manner so that the molar ratio is 1 to 1:20.

First, as shown in (I) below, the hydroxyl group below the ring-opened copolymer is reacted with one isocyanate group of the diisocyanate compound of the above formula (6) to obtain component B, which is said to be in a so-called half-block state.

"Roml-←Parrot j1 碍弘ふ]-0H+ 0CN-R4
-NCO→Kasumi Wataru I Setsu-0-C-NH-R, NCO(I
) Component B However, as mentioned above, R4 is a linear chain having 4 to 20 carbon atoms,
Indicates a branched, alicyclic, or aromatic hydrocarbon group.

Subsequently, components A and B are mixed in a desired molar ratio and reacted. This reaction occurs between the isocyanate group at the end of the B component resulting from the half-blocking of the ring-opened copolymer and the amino group or imino group in the A component, and the A component and the B component are bonded together through a urea bond. Join.

If the molar ratio of component B/component A is less than 1:1, a sufficient steric repulsion layer will not be formed, resulting in poor pigment dispersibility. Also B
If the component/component A molar ratio exceeds 20:1, the pigment dispersant is likely to be detached from the pigment surface, resulting in a decrease in pigment dispersibility.

In addition, considering the amount of the pigment to be blended in a practical paint, the pigment dispersant of the present invention can be obtained by reacting with the above-mentioned method and within the molar ratio range. The amine value of the dispersant is 10 to 300+ng KOH/
A range of g is preferred.

When the amine value is less than 10 KOH/g, the amount of pigment dispersant added to the paint becomes very large. for that,
For paints with unique resin designs, this may have an adverse effect on coating performance such as hardness and flexibility. If the amyl-divalent value exceeds 300 mg KOH/g, the ratio of component A, which is the adsorption part of the pigment dispersant, is too high, and the proportion of component B, which is the steric repulsion layer, is too small, resulting in an unbalanced pigment dispersant that is not sufficient. We cannot expect good dispersibility.

Next, a method for producing the pigment dispersant of the present invention will be explained.

First, the method for obtaining component B includes -hydric alcohols of formula (1), such as saturated aliphatic methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, decyl alcohol, 2-ethylhexyl alcohol, lauryl alcohol, stearyl alcohol; Formulas (2) to (4) are prepared using alicyclic cyclopentanol, cyclopentanol, aromatic benzyl alcohol, etc. as starting materials.
The monoepoxy compound of formula (5) and the lactone compound of formula (5) are ring-opening copolymerized at 0 to 180°C.

Examples of monoepoxy compounds include monoepoxy compounds of formula (2), such as straight ethylene oxide, propylene oxide, heptene oxide, alicyclic cyclopentene oxide, aromatic styrene oxide;
) monoepoxy compounds, such as butyl glycidyl ether, cyclohexyl glycidyl ether, phenyl glycidyl ether; monoepoxy compounds of formula (4),
Examples include glycidyl acetate, glycidyl butyrate, glycidyl decanoate, glycidyl laurate, glycidyl stearate, glycidyl perzatate, phenylglycidyl ester, and glycidyl p-tert-butylbenzoate. As the lactone compound of formula (5), β-caprolactone, γ-caprolactone, ε-
Examples include caprolactone.

The polymerization is carried out by ring-opening polymerization in the presence of a catalyst such as lithium, sodium, lithium hydride, sodium methylate, sodium ethylate, aluminum propoxide, dimethylbenzylamine, triethyltin, trichloroaluminum, toluenesulfonic acid, etc. By carrying out this method, a polyester compound having a hydroxyl group at the end of the molecule is obtained.

Subsequently, this polyester compound and a diisocyanate compound of formula (6), such as tolylene diisocyanate, inphorone diincyanate, 4,4' diphenyl isocyanate-1, hexamethylene diisocyanate, methylcyclohexane-2,4 (2,6)-diisocyane-1
・, 4,4′ methylene bis(cyclohexyl isocyanate), ■.

One isocyanate group such as 3-(isocyanatomedyl)cyclohexanetrimethylhexanemethylene diisocyanate, dimer acid diisocyanate-1, etc. and 0°C
The reaction is carried out at ~80°C to obtain a half-blocked component B that modifies the terminal hydroxyl group of the ring-opened copolymer into an isocyanate group.

Next, component A, which is a polyalkylene polyamine having one or more active hydrogen atoms per molecule and having a number average molecular weight of 60 to 20.000, is added at a molar ratio of component B/component A of 1/1 to 1/1. Mix at a ratio of 20/1, 00C
The pigment dispersant of the present invention is obtained by reacting at ~100°C.

Pigments to which the pigment dispersant of the present invention can be applied include titanium dioxide, zinc oxide, cadmium sulfide, iron oxide, zinc white,
Inorganic pigments such as red lead, zinc sulfide, barium sulfate, carbon black, barium carbonate, azo type, diazo type, condensed azo type, thioindigo type, indanthrone type, isoindanthrone type, anthrathrone type, anthraquinone type, penzi midasolone series, stalocyanine series, quinacridone series, pyranthrone series, isoindolinone series, perylene series,
It has excellent pigment dispersibility for organic pigments such as perinone, anthrapyridine, and furanochlorinated pigments.

In the pigment dispersant base composition using the pigment dispersant of the present invention, the optimum amount to be used varies depending on the type of pigment dispersant and the composition of the coexisting resin, but the solid content value of the dispersant with respect to the pigment to be dispersed varies. , added in a range of 1% to 500%.

If the amount of pigment dispersant added to the pigment is less than 1%, sufficient pigment dispersibility cannot be obtained. 500 again
%, there is a free pigment dispersant that is not adsorbed on the pigment surface (7, the viscosity of the dispersion base becomes excessively high,
Like (not 7)

(Effects of the Invention) Component B of the pigment dispersant of the present invention has good affinity with a wide range of resins as an effect of ring-opening copolymerization of a -hydric alcohol, a monoepoxy compound, and a lactone compound. Therefore, the pigment dispersant of the present invention has good affinity with various paint resins, and the coating film obtained using the pigment dispersant has excellent gloss and sharpness. In addition, as another effect, the pigment dispersant of the present invention does not precipitate in the paint even at low temperatures, so it does not impair the appearance and has excellent low-temperature stability.

Further, since the dispersion base produced using the pigment dispersant of the present invention has a low viscosity, it is possible to produce a paint with a high solids content and has excellent storage stability.

(Examples) Hereinafter, the pigment dispersant of the present invention will be explained with reference to Examples, Comparative Examples, Applied Examples, and Applied Comparative Examples. In these examples, "parts" are parts by weight, and "%" are % by weight.

Example 1 183 parts of xylene, 34 parts of decyl alcohol,
Add 1 part of sodium methylate and heat to 130°C to 14°C.
The temperature was raised to 0°C, and ε-caprolactone 200% was added under a nitrogen atmosphere.
196 parts of phenyl glycidyl ether were added dropwise over 2 hours. It was held for an additional 5-6 hours. After polymerization,
Cool to about 20°C and add tolylene diisocyanate-1 and 3.
7 parts and 282 parts of xylene were added and stirred for 1 to 3 hours. When 50% of the isocyanate groups have reacted, Epomin 5POO6 (manufactured by Nippon Shokubai Kagaku Kogyo ■, trade name) 33
and 34 parts of t-butyl alcohol were added thereto, followed by stirring at 30° C. for 1 hour to obtain a pigment dispersant (1) of Example 1.

The properties of the obtained pigment dispersant (1) are shown in Table 1.

Pigment dispersants (2) to (2) of Examples 2 to 9 and Comparative Examples 1 to 2 were prepared in the same manner as in Example 1 using the raw material components shown in Table 1.
11) was manufactured. Table 1 shows the characteristic values of these dispersants.

Application Example 1 Using the pigment dispersant (1) obtained in Example 1, the pigment was dispersed in a paint shaker (manufactured by Red Devil Co., Ltd., trade name) according to the dispersion formulation shown in Table 2 to obtain a dispersion base a. .

Next, use this dispersion base to create a paint according to the paint formulation shown in Table 2, add thinner for dilution (cellosolve acetate/xylene-50 150% mixed solvent), and reduce the viscosity to 20 seconds (25°C) using a Ford cup N014. After adjusting so that the steel plate (JIS G 3141) is coated with Aqua No.
Apply 2011 m of the product (trade name), then apply Hi-Epico N011 EP Sealer (NOF ■) as an intermediate coat on top of this.
Co., Ltd., product name) was spray-painted with a thickness of 30 μm and heated at 140℃.
A test piece was obtained by baking for 0 minutes. 6 of the obtained test pieces
The 0 degree specular gloss was measured.

After the above-mentioned paint was left at 0° C. for 5 days and a low-temperature stability test was conducted, a test piece was prepared by the method described above, and the 60 degree specular gloss was measured. The results are shown in Table 2.

Application Examples 2 to 15 and Application Comparative Examples 1 to 4 Dispersion was carried out in the same manner as in Application Example 1 using the dispersion formulation shown in Table 2 to obtain a dispersion base b ``'' S. Using each dispersion base, create a paint according to the paint formulation shown in Table 2,
A test piece was prepared in the same manner as in Application Example 1, and the 60 degree specular gloss was measured. After conducting a low temperature stability test in the same manner as in Application Example 1, the 60 degree specular gloss of the test piece was measured. These results are shown in Table 2.

Note 1) Cardura-E-10 manufactured by Shell Chemical Co., Ltd., trade name, glycidyl ester of persatic acid Note 2), 3), 4), 5) Epomin 5POO6, 5PO12, 5PO18, 5P2
00 Nippon Shokubai Chemical Co., Ltd., product name, polyethyleneimine Epomine 5POO6 Molecular weight 600 Epomin 5P012 Molecular weight 1.200 Evomin 5P018 Molecular weight 1.800 Epomin 5P20
0 molecular weight io, oo.

Note 1), Note 2) Acrylic resin as a film-forming component for acrylic resin paint was produced as follows.

The solvents shown in Table 3 were charged into a reaction vessel equipped with a reflux condenser, a nitrogen gas introduction tube, a thermometer, a stirring blade, and a monomer dropping device, and the temperature was raised to the reflux temperature under a nitrogen stream. While maintaining the reflux state, a mixture consisting of each monomer listed in Table 3 and t-butyl peroxybenzoate as a polymerization initiator was added dropwise over a period of 2 hours. After the dropwise addition was completed, the mixture was further stirred under reflux for 5 hours to complete the polymerization, thereby producing the desired acrylic resin varnishes AC-1 and AC-2.

Table 1) Plaxel FM-2: Manufactured by Daicel Chemical Industry ■, trade name (lactone-modified acrylate monomer) Note 3), Note 4
) Polyester resin PE5-1, polyester resin P
E5-2 A polyester resin as a film-forming component for a polyester resin paint was produced as follows.

The solvents and raw materials shown in Table 4 were charged into a reaction vessel equipped with a reflux condenser, a nitrogen gas introduction tube, a thermometer, a stirring blade, and a dehydration device, and heated under a nitrogen stream to an upper limit temperature of 230° C. while stirring.

Water produced as the reaction progressed was removed by azeotroping with xylene, and heating was continued until the acid value reached about 10 to complete the reaction. The obtained resin was heated with xylene to a residual amount of 60
% of the desired polyester resin P.
E5-1°PE5-2 was obtained.

Table 1) Cardura-E-10 manufactured by Shell Chemical Co., Ltd., trade name, glycidyl ester of persatic acid Note 5) Chikun Oxide JR602: (manufactured by Teikoku Kako ■, trade name) Note 6) Tsuba Palm Red F3RK-70: ( Monoazo organic pigment, manufactured by Hoechst, trade name) Note 7) First Gen Blue RGA: (Copper phthalocyanine organic pigment, manufactured by Dainippon Ink & Chemicals, trade name) Note 8) Rubicron Red 500RG: (quinacridone organic Pigment, Tosoh (product name) Note 9) Addition of pigment dispersant to pigment Note 10) Melamine resin Newpan 220 (manufactured by Mitsui Toatsu Chemical Co., Ltd., product name) Heating residue 60% Note) Leveling agent : Modaflow, manufactured by Monosand Company, trade name, Modaflow 10% xylene solution As is clear from Application Examples 1 to 15 in Table 2, the pigment dispersant of the present invention can be used for a wide range of paints such as acrylic resins and polyester resins. It can be applied to resins, and as a result of improved dispersibility, the gloss of the coating film was excellent.

Moreover, the low-temperature stability was also good, and a low-temperature stability test revealed that the pigment dispersant did not precipitate in the paint, and as a result, no decrease in paint film gloss was observed.

On the other hand, in Application Comparative Examples 2 and 3 using a pigment dispersant with a monoepoxy compound/lactone compound molar ratio of 9°510.5, the coating gloss of the acrylic resin was poor, and there were restrictions on the resin used. was there.

Also, the molar ratio of monoepoxy compound/lactone compound is 0.
．． Comparative application example 1 using a pigment dispersant with a rating of 5/9.5
As a result of a low-temperature stability test, a decrease in coating film gloss was observed.

Application Comparative Example 4, which does not use a dispersant, is obtained by replacing the pigment dispersant of Application Example 2 with acrylic resin AC-1, and corresponds to a system that does not contain a dispersant, but the 60 degree gloss of the coating film is inferior.

From the above, the effects of using the pigment dispersant of the present invention can be seen.

Claims (1)

[Claims] 1. The following A component: A polyalkylene polyamine compound having one or more active hydrogen atoms per molecule and a number average molecular weight of 60 to 20,000, and the following B component: The following formula R_1- OH...(1) (R_1 in the formula is a linear or branched chain having 1 to 24 carbon atoms,
(representing an alicyclic or aromatic hydrocarbon group) and the following formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼... (2) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼...・(3) Or ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(4) (R_1 in the formula indicates the same as above, R_2
represents a hydrogen atom or a linear, branched, alicyclic, or aromatic hydrocarbon group having 1 to 24 carbon atoms) and a monoepoxy compound represented by the following formula ▲ Numerical formula, chemical formula, table, etc. There is a ring-opened copolymer with a lactone compound represented by ▼...(5) (R_3 in the formula represents an alkylene group having 1 to 20 carbon atoms) and the following formula ▲ Numerical formula, chemical formula, table, etc. ▼...(6) (R_4 in the formula is a linear or branched chain having 4 to 20 carbon atoms,
(representing an alicyclic or aromatic hydrocarbon group) has an isocyanate group at the molecular end and has a number average molecular weight of 500 to 10,00.
1. A pigment dispersant comprising a product obtained by reacting a polymer compound of 0.0 with a molar ratio of component A and component B of 1:1 to 1:20. 2. The pigment dispersant according to claim 1, wherein the molar ratio of the monoepoxy compound and the lactone compound as component B is 1:9 to 9:1.