JPS6123829B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pigment paste for coloring polyurethane, and more specifically, the present invention relates to a pigment paste for coloring polyurethane. This invention relates to a pigment paste for polyurethane coloring that has improved flowability and color separation in the case of mixed colors.

Conventionally, dyes or pigments have been used as colorants for polyurethane foams. Generally, these colorants are dissolved or dispersed in a high-boiling medium such as a plasticizer or in a polyol component, and then reacted with a polyisocyanate component. Alternatively, colored polyurethane foams have been produced by foaming with halogenated lower hydrocarbons.

However, although dyes can provide uniform coloring due to their solubility, due to their solubility, they have poor water resistance, oil resistance, and bleed resistance, and their light resistance is also unsatisfactory. isn't it. On the other hand, pigments have poor dispersibility and stability in polyol components, as well as poor dispersion stability during reaction with polyisocyanate components, and generally agglomeration of pigments occurs in each of the above steps, resulting in a decrease in coloring power, There are problems such as dull hue.

Various studies have been made to solve the above problems. Namely, (1) a method of treating a pigment with a surfactant, (2) a method of treating a pigment with a modified sutucarose, (3) a method of using a lipophilic pigment obtained by binding a cationic dye to bentonite, and (4) a method of using a lipophilic pigment obtained by binding a cationic dye to bentonite. A method using a dye into which an active hydrogen group capable of reacting with an isocyanate group is introduced, (5) A method using carbon black that has been reacted with an isocyanate compound in advance (Japanese Patent Publication No. 47-35769), (6) Aromatic diisocyanate , a method of preparing a pigment paste using a low molecular weight polyurethane resin with a polyol and a monoalcohol (Japanese Unexamined Patent Publication No. 117820/1983).

However, method (1) does not provide sufficient dispersion stability, and due to the presence of surfactants,
Water resistance and oil resistance are poor, and it also causes pigment bleeding and color transfer. In method (2), the effect on dispersion stability cannot be obtained unless the amount of modified satucalose relative to the pigment is relatively large, and the pigment concentration in the colorant becomes low, and depending on the type of polyurethane forming component, the modification There is a problem in that the type of satsucrose needs to be changed. Methods (3) to (5) are not industrially practical because the types of colorants that can be used are limited. In method (6), it is necessary to heat (approximately 100°C) to dissolve the obtained low-molecular-weight polyurethane resin in the polyol component, and it is also necessary to heat the obtained low-molecular-weight polyurethane resin in the polyol component. There are still problems to be solved, such as not sufficiently preventing the aggregation of.

As a result of intensive research to solve the above problems, the present inventors have developed a resin composition containing a hydroxyl group-containing prepolymer obtained by reacting a part of the hydroxyl groups of a polyester polyol or polyether polyol with a molecular weight of 300 to 6000 with a polyisocyanate compound. When used as a pigment dispersion medium, the dispersion stability at each stage is significantly improved, there is no pigment aggregation, the coloring power is increased, and the paste obtained by kneading the pigment into the resin composition has thixotropic properties. The present invention was completed based on the knowledge that the fluid has excellent fluidity.

That is, the present invention combines a polyester polyol or polyether polyol with a molecular weight of 300 to 6000 and a polyisocyanate compound by NCO/OH
The present invention provides a pigment paste for polyurethane coloring, which comprises 20 to 97 parts by weight of a resin composition containing a hydroxyl group-containing prepolymer obtained by reacting them at a ratio of 0.05 to 0.7, and 3 to 80 parts by weight of a pigment.

The polyurethane colored pigment paste according to the present invention has good dispersibility of the pigment in the polyol component, dispersion stability, and fluidity, and there is no aggregation of the pigment even when reacting with the polyisocyanate component.
Therefore, a vivid and highly concentrated colored product can be obtained, and since the pigment dispersion medium is incorporated into the polyurethane product, bleeding will not occur, and there is a risk of deterioration of various resistances such as water resistance and oil resistance. It is possible to use part of the polyol component and polyisocyanate component designed by the raw material manufacturer or molding manufacturer as raw materials for the pigment dispersion medium, so there is no change in the design even if a pigment is added. It is extremely valuable industrially.

In the present invention, the polyester polyol is obtained by condensing a polycarboxylic acid or its anhydride with a polyol. Typical carboxylic acids include adipic acid, glutaric acid, suberic acid, sebacic acid, azelaic acid, phthalic acid, terephthalic acid, isophthalic acid, and trimellitic acid, and typical polyols include ethylene glycol and propylene glycol. , butylene glycol, glycerol, trimethylolpropane, and pentaerythritol. Polyether polyols include those obtained by polyoxyalkylation of polyols,
Examples include poly(oxyethylene) glycol, poly(oxypropylene) glycol, poly(oxyethylene) trimethylolethane, poly(oxypropylene) diethylene glycol, and the like.

The molecular weight of the polyester polyol and polyether polyol is in the range of 300 to 6,000 and contains 2 to 6, preferably 2 to 3, hydroxyl groups in the molecule. When the molecular weight is less than 300, the resulting pigment paste lacks dispersion stability, and when a large amount of the pigment paste is added to the polyol, the resulting urethane foam tends to become hard. On the other hand, if the molecular weight is 6000 or more, the fluidity of the pigment paste obtained will be reduced, and if the amount of pigment paste added to the polyol is large, the compressive strength of the urethane foam will be reduced.

In the present invention, the polyisocyanate compounds include p-phenylene diisocyanate, biphenyl diisocyanate, tolylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 1,4-tetramethylene diisocyanate, hexamethylene diisocyanate,
Examples include 2,2,4-trimethyl-1,6-hexylene diisocyanate, methylene bis(phenyl isocyanate), lysine methyl ester diisocyanate, isophorone diisocyanate and methylcyclohexyl diisocyanate, and polyphenylene methylene polyisocyanate.

In the present invention, a polyester polyol or a polyether polyol and a polyisocyanate compound are reacted at a ratio of NCO/OH of 0.05 to 0.7 to obtain a resin composition containing a hydroxyl group-containing prepolymer. For this reaction, an appropriate amount of triethylenediamine, triethanolamine, triethylamine, etc. is used as a catalyst, usually 0.001 to 0.5% by weight based on the total amount of polyol and polyisocyanate, and if necessary, heating and stirring can facilitate the reaction. The object is obtained.

When NCO/OH is less than 0.5, problems tend to occur in pigment dispersion stability, and when NCO/OH exceeds 0.7, fluidity is lost even in hydroxyl group-containing prepolymers obtained from diols and diisocyanates.

The pigment used in the present invention is not limited in itself, and any known pigment that is normally used for coloring synthetic resin paints, synthetic resins, etc. can be used.
Namely, azo series, anthraquinone series, phthalocyanine series, quinacridone series, isoindolinone series,
Organic pigments such as dioxazine, perylene, quinophthalate, and perylene pigments and inorganic pigments such as cadmium sulfide, cadmium selenide, ultramarine, titanium dioxide, iron oxide, chromium oxide, lead chromate, and carbon black can be used.

In the present invention, in order to obtain a pigment paste, the resin composition containing the hydroxyl group-containing prepolymer 20 to
97 parts by weight of the pigment and 3 to 80 parts by weight of the above pigment may be mixed and dispersed using a known kneading device such as a colloid mill, a ball mill, or a roll mill.

Furthermore, depending on the purpose, additives such as flame retardants, fillers, ultraviolet absorbers, and antioxidants may be used together with the pigments to the extent that they do not impair the effects of the present invention.

When the pigment paste according to the present invention has the same pigment content, the fluidity is improved compared to the case where the pigment is not treated with polyester polyol or polyether polyol, and the dispersion in polyester polyol or polyether polyol becomes easier and the concentration is lowered. It is possible to reduce the amount added because it improves
Due to its good dispersion stability, it has the advantage of less color separation in blended colors. In addition to this, if a large amount of other additives are to be added, or if a prepolymer is synthesized using polyester polyol or polyether polyol and polyisocyanate used for urethane foam formation, raw material manufacturers or molding manufacturers may A major feature of this method is that it is possible to produce a pigment paste that does not impair the physical properties of the designed urethane foam.

The present invention will be specifically explained using the following examples and comparative examples.

Example 1 800 g of polyether polyol having a hydroxyl value of 54 and an average molecular weight of about 3000 (Sannix G-P3000, manufactured by Sanyo Chemical Co., Ltd.), Stanus Octoace 0.1
A resin composition containing a prepolymer was obtained by stirring 16 g of tolylene diisocyanate (a mixture of 80% 2,4-tolylene diisocyanate and 20% 2,6-tolylene diisocyanate) at 50°C for 3 hours.
At this time, the viscosity of the resin composition, which was initially 450 cps (at 25°C, the same applies hereinafter), rose to 1600 cps. Sample 1 is a pigment paste obtained by adding 10.6 g of carbon black (Mitsubishi Carbon #45, manufactured by Mitsubishi Chemical Industries, Ltd.) to 60 g of this resin composition and passing it through a triple roll three times.

Example 2 Sample 2 is a pigment paste obtained by adding 50 g of titanium dioxide (Tapeque CR-80, manufactured by Ishihara Sangyo Co., Ltd.) to 50 g of the resin composition obtained in Example 1 and passing it through a triple roll three times.

Example 3 Phthalocyanine green (Lionol Green YS, manufactured by Toyo Ink Manufacturing Co., Ltd.) was added to 140 g of a polyether polyol (Sumifuen 3900, manufactured by Sumitomo Bayer Urethane Co., Ltd.) having a hydroxyl value of 35 and an average molecular weight of 4800.
Sample 3 is a pigment paste in which 60g is added and passed through a triple roll three times.Sample 3 is 100g and NCO content is 31.
% polyphenylpolymethylene polyisocyanate (Millionate MR-200, Japan Polyurethane
Co., Ltd.) 1.5g, dibutyltin dilaurate 0.03g
Sample 4 is a pigment paste obtained by stirring at 50°C for 3 hours.

Example 4 Polyester polyol with a hydroxyl value of 86 and an average molecular weight of about 1000 (Edyform E-502, Kao Soap
Co., Ltd., 0.1 g of Stanus Octoate, and 53 g of Millionate MR-200 were stirred at 60° C. for 1 hour to complete the reaction. Add 25.6 g of disazo yellow (Lionol Yellow NBR, manufactured by Toyo Ink Manufacturing Co., Ltd.) to 60 g of this hydroxyl group-containing prepolymer, and
Sample 5 is a pigment paste that has been passed through this roll three times.

Comparative Example 1 A pigment paste sample 6 was prepared in which Sanix G-P3000 was used instead of the resin composition containing a hydroxyl group-containing prepolymer in sample 1.

Comparative Example 2 Sample 7 was prepared by using SANNIX G-P3000 instead of the resin composition containing the hydroxyl group-containing prepolymer in Sample 2.

Comparative Example 3 Sample 8 was prepared by using Ediform E-502 instead of the resin composition containing the hydroxyl group-containing prepolymer in Sample 5.

Comparing Sample 1 and Sample 6, Sample 6 had no fluidity, whereas Sample 1 had fluidity. Sample 1
When 5 g was added to 100 g of Sannix G-P3000 and stirred, it was quickly dispersed. To this colored polyether polyol, 4.0 g of water, 0.1 g of triethylenediamine, 1.0 g of silicone resin (SH-190, manufactured by Toray Silico Co., Ltd.), and 0.4 g of stannous octoate.
After stirring, 49 g of tolylene diisocyanate was added to produce urethane foam. The foaming properties were not impaired and the foam was colored uniformly black. In order to obtain the same concentration, when foaming is carried out under the same conditions, sample 6 must be Sannix G-P3000,
It was necessary to add 9g to 100g.

When 1 g of a mixture of 1 part of Sample 1 and 10 parts of Sample 2 was dispersed in 100 g of Sannix G-P3000, no separation of pigment was observed even after being left at 25°C for 7 days. 1 g of a mixture of 1 part of Sample 6 and 10 parts of Sample 7 was added to Sannix G-
When dispersed in 100 g of P3000, separation and precipitation of titanium dioxide was observed after being left for 7 days.

Compared to sample 3, sample 4 has improved flowability, and in the case of sample 4, in which urethane foam is manufactured under the same conditions as above by adding 2g to 100g of Sannix G-P3000, the fluidity is much improved compared to sample 3. It was very clear.

Comparing Sample 5 and Sample 8, Sample 5 had no fluidity even at 30°C, but Sample 8 had good fluidity.

Claims (1)

[Claims] 1 20 to 97 parts by weight of a resin composition containing a hydroxyl group-containing prepolymer obtained by reacting a polyester polyol or polyether polyol with a molecular weight of 300 to 6000 and a polyisocyanate compound at a ratio of NCO/OH of 0.05 to 0.7, and a pigment. 3～80
Pigment paste for polyurethane coloring consisting of parts by weight.