MXPA01001424A - A polymeric pigment dispersant having an acrylic backbone, polyester side chains, cyclic imide groups and quaternary ammonium groups - Google Patents

Abstract

A polymeric pigment dispersant of a graft polymer having an acrylic polymer backbone and pending from the backbone, polyester side chains, cyclic imide groups and quaternary ammonium groups and the polymer having a calculated number average molecular weight of 8,000-50,000;wherein the graft copolymer is composed of:(a)10-50%, by weight of the graft polymer, of an acrylic copolymer backbone having a number average molecular weight of 2,500-10,000 which, before reaction, contains 25-75%by weight of polymerized oxirane containing monomers;(b) 20-85%, by weight of the graft polymer, of a polyester copolymer, or mixture of different polyester copolymers, having a number average molecular weight of 500-10,000 which polyester copolymer is carboxylic acid functional and is attached to the backbone by a reaction of the carboxylic acid functional group with oxirane group of the backbone;(c) 1-16%, by weight of the graft polymer, of cyclic imide groups attached to the backbone by a reaction of the imide group with the oxirane group of the backbone and (d) 0.2-17%, by weight of the graft polymer, of quaternary ammonium groups.

Description

A DISPERSANT OF POLYMERIC PIGMENT THAT HAS A. MAIN ACRYLIC CHAIN, SIDE CHAINS POLYESTER, IMID CYCLIC GROUPS AND QUATERNARY AMMONIUM GROUPS Description of the invention The polymeric pigment dispersants of this invention are polyester / acrylic graft polymers having cyclic imide groups and quaternary ammonium groups. These dispersants are useful for dispersing a wide variety of pigments.

Most useful pigment dispersants are widely compatible with other polymers, are selectively absorbed by a wide range of pigments, are soluble in a wide range of solvents, and do not move from pigmented surfaces to polar solvents. Certain pigments are particularly difficult to disperse, for example natural gas carbon black pigments, and require special dispersants that do not allow pigments to coagulate or cause an increase in viscosity.

Ref: 126762 of the resulting paint composition or dispersion.

The U.S. Patent 5,424,364 to Simms et al., Issued Jun. 13, 1995, teaches the use of combined acrylic polyester polymers having imide groups as pigment dispersants. Already amoto and collaborators in the U.S. Patent published on February 16, 1993 shows an acrylic polyester polymer containing amine groups that are used as pigment dispersants. European Patent Application 0 458 479 A2 published on November 27, 1991 shows dispersants of acrylic polymer pigments having tertiary amino groups and / or nitrogen containing nitrogen rings and a particular polyester component.

Although these pigment dispersants are suitable, it is necessary for pigment dispersants that can be easily prepared and be more effective in dispersing a wide variety of pigments in various coating compositions used in the field of high performance coatings.

Brief Description of the Invention This invention is directed to a polymeric pigment dispersant of a graft polymer having an acrylic polymer column and polyester side chains pendant to the column, cyclic imide groups and quaternary ammonium groups, and the polymer has an average molecular weight of calculated number of 8,000-50,000; wherein the graft copolymer is composed of (a) 10-50% by weight of the graft polymer, of an acrylic copolymer column having a number average molecular weight of 2,500-10,000 which, before the reaction, contains 25-75% by weight of the polymerized oxirane containing monomers; (b) 20-85%, by weight of the graft polymer, of a polyester copolymer, or a mixture of different polyester copolymers, having a number average molecular weight of 500-10,000 whose polyester copolymer is carboxylic acid functional and adheres to the column by a reaction of the carboxylic acid functional group with an oxirane group on the column; (c) 1-16%, by weight of the graft polymer, of cyclic imide groups adhered to the column by a reaction of the imide group with the oxirane group of the column and (d) 0.2-17% by weight of the graft polymer, of quaternary ammonium groups.

These dispersants are useful for dispersing a wide variety of pigments and in particular natural gas carbon black pigments and are useful in solvent-borne coatings where they provide an improved efficiency of the pigments used, low paint viscosity, and a reduced emission of volatile organic solvents.

Detailed description of the invention.

The polymeric pigment dispersant of this invention is a graft polymer having from 10-50% by weight of an acrylic polymer column, from 20-85% by weight of polyester side chains adhered to the column, from 1-16. % by weight of cyclic imide groups adhered to the column and 0.2-17% by weight of quaternary ammonium groups also adhered to the column. The improvement made in this invention is the presence of two separators and different functional groups adhered to the polymer column, which are cyclic imide groups and quaternary ammonium groups.

The graft polymer has a calculated number average molecular weight of 8,000-50,000. The number average molecular weight is calculated by adding the number average molecular weight of each of the components used, ie, the acrylic polymer column, the polyester side chains, cyclic imide groups and the quaternary ammonium groups, in the molar portions used to form the graft polymer.

These dispersants are prepared by reacting an oxirane-substituted acrylic polymer with a polyester or functional carboxylic acid polyesters, an amide containing a compound such as phthalimide and a precursor for a quaternary ammonium group such as a hexamethyl ienoimine in the presence of a catalyst and subsequently reacting with a quaternizing compound such as an aryl halide, for example, benzyl chloride to form the quaternary ammonium group. The preferred method for making the dispersant of this invention is to simultaneously react the carboxyl containing the polyester polymer forming the side chains of the graft polymer, a cyclic imide, a precursor of a quaternary ammonium group with an oxirane containing an acrylic column polymer and subsequently alternating the precursor to form the quaternary ammonium group. In this method, the oxylene groups of the acrylic column react with the carboxyl groups of the polyester polymer as well as with the cyclic imide and the precursor of the quaternary ammonium group. Alternatively, a compound containing a quaternary ammonium group and a carboxyl group, can be added directly with the other constituents to the oxirane containing the polymer of the acrylic column and react simultaneously with the other constituents to form the quaternary ammonium group of the polymer of graft.

POLYESTER SIDE CHAINS In the manufacture of the polymeric pigment dispersant, the polyester polymers used for the side chains are functional mono-carboxy and can be prepared by one of the numerous methods. This is possible to ensure the monofunctionality of the polyester and the molecular weight of the polyester can be controlled. Pigment dispersants with polyester side chains having an Mn (number average molecular weight) below 500 are not very likely to produce non-coagulated dispersions. Those with polyester side chains that have an Mn above 10,000 do not necessarily form viscous pigment dispersions.

The methods of preparing the polyester will be described first, and subsequently the synthesis of the graft polymer used as the polymeric pigment dispersant will be discussed. As indicated above, the dispersant comprises about 20-85% by weight of the dispersant, of a carboxylic polyester. Such suitable polyesters have an Mn of 500-10,000, preferably 1,000-8,000.

With respect to the preparation of the polyester, the homopolymerization of hydroxy acids or the copolymerization of hydroxy acids with lactone, such as caprolactone, is an excellent approach to the synthesis of the monocarboxylic polyesters. These polyesters also have a terminal hydroxyl group except monocarboxylic acid, typically, a saturated or unsaturated fatty acid such as stearic acid, is introduced during the termination to plug these hydroxyl groups. The methosulonic acid or toluensulonic acid are useful catalysts for polymerization. Different concentrations of caprolactone can be used in the polyester and provide a tool to vary its solubility and compatibility of the pigment dispersant. For example, caprolactone can be added to form 60% polyester and the acid concentration decreases from about 28-15 (measured as mg KOH / g polyester) and polyester Mn increases from about 2,000 to around of 3,500 (calculated from the acid number). The molecular weight is determined by the size of the exclusion chromatography using standard polystyrenes increased from about 3,700 to 6,000. The increase in molecular weight is also reflected in the viscosity of the products, which at 89% solids increase from 10 Stokes to around 50 Stokes.

The reaction of 2,2'-bis [hydroxymethyl) propionic acid with caprolactone provides another useful way to make the mono-acid functional polyester used in the graft polymer of the pigment dispersant. The extent of the modification of caprolactone that is considered to be the most useful is 2-8 units of caprolactone in a typical polyester, with the preferred value being 2-6. The use of these polyesters has the advantage of providing hydroxyl groups in the side chains by the subsequent reaction with melamine, isocyanate or anhydride crosslinkers. The citric acid, trihydroxy acid, can also be used to form a trihydroxy / mono-acid polyester.

Other hydroxy acids and lactones may be used to form useful polyesters for the pigment dispersant.

Useful polyesters can also be formed from oxyhydrogen / anhydride copolymers by the alternative copolymerization of epoxides with cyclic anhydrides. The initial species may be either an alcohol or a monocarboxylic acid for the purpose of the invention. Using an excess of anhydride, the final group will be an acid, and the product will be a monocarboxyl functional polyester useful in this invention to form the pigment dispersant.

Caprolactone polyesters using 2-ethylhexanol as the starting alcohol and dibutyl tin dialurate as the catalyst which react with a cyclic anhydride to form a terminal acid group are also useful.

The monoacid functional polyesters of lauric acid and caprolatone can be used. The lauric acid is used to initiate the polymerization of caprolactone typically by reacting these constituents for 2 hours at 180 ° C and then further polymerizing with a catalyst such as tetrabutyl titanate for 16 hours at 220 ° C to form the polyester.

It is also possible to use the polyester polyols of diols, triols, acids, anhydrides and diesters. These polyesters are usually not termed to contain any acid. Many of these materials have a number average molecular weight of 1,000-6,000 and contain residual carboxyl groups on the average of one or less per molecule. In this way, these copolymers are mixtures of acid-free polyester polyols and polyols containing an acid group. The acid functional component of the mixture serves as the polyester chain in the polymer. The functional non-acidic residual polyol is an inert diluent.

The acid number of useful polyesters is between about 5 and 30, with a preferred range of 10 to 20.

A combination of two different polyesters can be used to form the side chains of the graft polymer. A preferred combination is a polyester having hydroxyl groups, for example, a caprolactone polyester and an acid-containing hydroxy, such as dimethyolpropionic acid, and an entropic polyester, for example, of caprolactone and 12-hydroxystyric acid and non-octanoic acid. By using two polyesters, a dispersant can be formed which optimizes both the reactivity with the binder of a coating composition through the hydroxyl groups of the polyester containing hydroxy and provides steric stabilization by the entropic polyester which is essentially free of hydroxyl groups.

An entropic polyester is a polyester long enough to provide a layer around the pigment to be dispersed 5-20 nanometers in thickness. The thickness of the polyester layer can be estimated by calculating the extended chain length of the polyester by adding the number of bonds in the chain between atoms and multiplying by 0.125 nanometers. These will be a minimum of 5 / 0.125 = 40 chain links. The polyesters that are of > 1000 Mn meet these length requirements.

It is preferable to have at least 2.5 entropic polyester arms in the graft polymer having an Mn of 2,000. These provide stabilization and do not increase the viscosity of the pigment dispersion. The high molecular weight polyesters armed in the graft polymer increase the viscosity of the resulting pigment dispersion.

COLUMN OR MAIN CHAIN OF ACRYLIC The polymeric dispersants comprise from 10-50%, preferably from 15-40%, by weight of the dispersant, of an acrylic column polymer having an Mn of 2,500-10,000, preferably of 2,500-8,000, and which (before the reaction) contains 25-75% by weight of an oxirane containing monomers to provide good functionality for grafting while still producing relatively low viscosity dispersions. Typically, the column comprises an alkyl or methacrylate acrylate having 1-12 carbon atoms in the alkyl and methacrylate or glycidyl acrylate group in a weight ratio of or about 20/80 to 80/20. Preferred columns forming high-quality dispersants comprise glycidyl n-butyl methacrylate or methacrylate contained in a weight ratio of 50/50 to 30/70 and having a number average molecular weight of about 3,000. -5,000 A particularly preferred acrylic column contains n-butyl methacrylate / glycidyl methacrylate in a weight ratio of 40/60. The number of polyester arms, such as the entropic polyester arms and hydroxyl polyester arms, can be varied to change the concentration of the glycidyl methacrylate or acrylate in the acrylic column.

The acrylic column can contain 1-25% by weight of a methacrylate or alkyl hydroxyl acrylate having 1-4 carbon atoms in the alkyl group such as methacrylate or ethyl acrylate hydroxy, hydroxy propyl acrylate or methacrylate, methacrylate or butyl hydroxy acrylate.

The acrylic column polymer can be prepared by a conventional solution polymerization or by group transfer polymerization. In the solution polymerization, the monomers, solvents and catalysts such as an azo catalyst, for example Vazo 67, are charged into a polymerization vessel and reacted for about 0.5-4 hours at an elevated temperature to form the polymer acrylic .

IMI DA CÍCLICA The dispersant additionally contains a cyclic imide as an active pigment group. By the term imide, it means the group (= NH), wherein the rings are formed by nitrogen bonds in either the two carbonyl groups or a carbonyl and a sulfonyl. Phthalimide, maleimide, and succinimide are particularly useful examples of the first group, while saccharin is a particularly useful example of the second group. These react easily with the oxirane column using a base catalyst. These produce a neutral, low-colored polymer, which has no tendency to turn yellow during exposure. The most preferred is phthalimide.

The concentration of the cyclic imide in the dispersant is in the ranges from 1-16% by weight, with the preferred concentration being 4-12%. At low concentrations, there may not be enough interaction with the pigment to prevent coagulation, particularly in more polar solvents. At high concentrations, low polarity solvents may be unsatisfactory solvents for the dispersant.

QUATERNARY AMMONIUM GROUP The dispersant also contains quaternary ammonium groups to aid in the dispersion of difficult to disperse pigments such as natural gas carbon black. The dispersant contains 0.2-7% by weight of quaternary ammonium groups and preferably 2-12% by weight of quaternary ammonium groups. The quaternary ammonium groups work particularly well for the dispersion of pigments with anionic groups such as natural gas carbon black, sulfonated phthalocyanine or quinacridone pigments.

These are a number of techniques that can be used to form quaternary ammonium groups. A tertiary amine with a carboxyl group is reacted with the oxirane groups on the acrylic polymer column and then quaternized. The typical carboxyl contains tertiary amines including 1-piperidinepropionic acid, 3-dimethylaminopropionic acid. Cuat erni zant agents are typical include aryl halogens such as benzyl chloride, an aromatic sulfonate such as p-toluene methyl sulfonate, an alkyl sulfate such as dimethyl sulfate or an alkane sultone such as propane sultone.

Another technique that can be used to adhere quaternary ammonium groups to the acrylic column is to react the oxirane groups in the column with a quaternary ammonium compound containing a reactive carboxyl group. Such typical compounds are p-toluene betaine sulfonate and benzene dodecyl betaine sulfonate.

An additional method for adhering quaternary ammonium groups is to react a secondary amine with the oxirane groups on the acrylic polymer column and then quaternize the amine. Typical secondary amines include diethylamine, hexamethylene glycine which is preferred, N-benzyl methylamine, dibenzyl sheet, piperazine and morpholine. Any of the quaternized compounds mentioned above can be used, such as benzyl chloride to form the quaternary ammonium group.

To form a pigment dispersion or a ground base, the pigments are added to the dispersant and the pigments are dispersed using conventional techniques such as high speed mixing, ball milling, sand grinding, grinding in a grinder or two or three rollers. ground. The resulting pigment dispersion has a weight ratio of pigment to dispersant binder of 100/1 to 100/500.

Any of the conventional pigments used in paints can be used to form the pigment dispersion such as oxides similar to titanium dioxide, iron oxides of various colors, zinc oxide, natural gas carbon black, pigment fillings such as talc , china clay, barium oxide, carbonates, silicates and an extensive variety of organic pigments such as quinacr idonas, phthalocyanines, perylenes, azo pigments, indatrons, carbazoles such as carbazole violet, and soindolinones, thioindigio reds, benzimidazolinones, metal leaflets such as aluminum flakes, perillant flakes and the like.

It may be desirable to add other optional ingredients to the pigment dispersion such as antioxidants, flow control agents, rheological control agents such as silica vapor, microgels, UV stabilizers, scavengers, retarders and absorbers.

The dispersion pigments of this invention can be added to a variety of solvent coating compositions that carry a solvent such as a primer, surface active agents, surface coatings that can be a single coat or base coat of a final base coat . These compositions preferably have an acrylic polymer or polyester polymer or a mixture of these types of coating vehicles as the film forming the constituent and may also contain crosslinking agents such as blocked isocyanates, isocyanates, alkylated melamines, epoxy resins and the like. . Other film forming polymers can also be used, such as acryloureas, polyester urethanes, polyethers and polyether urethanes which are compatible with the polyglyceride dispersion. It is desirable that the film forming the polymer of the coating composition be similar to the polymer of the pigment dispersion so that in curing the polymer of the pigment dispersion it is cured with the coating polymer and is part of the film or coating . The dual nature (both acrylic and polyester) makes this more similar.

The following examples illustrate the invention. All parts and percentages are based on weight unless otherwise indicated. Molecular weights are determined by gel permeation chromatography using polystyrene as the standard and tetrahydrofuran as the carrier solvent.

EXAMPLES For the following examples, the synthesis of the polyester arms used by the dispersant and then the formation of the dispersant is described. Examples of dispersions of pigments formed with the dispersant will follow.

SYNTHESIS OF THE HYDROXYL POLYESTER ARM The three methods used to synthesize the hydroxyl arm are described hereinafter.

Method A.

The caprolactone, 2090.9 parts, and dimethyl-lolpropionic acid, 409.1 parts (a ratio of 6/1 moles) was charged to a reactor adapted with an agitator, a thermal coupler and a condenser plugged with a nitrogen inlet. The mixture was heated to 115CC with stirring for 1.5 hours. This was clarified when 103 ° C was reached by dissolving dimethyl and Ipropionic acid and exothermic when the heat was lowered to 115 ° C. The temperature was increased to 139.9 ° C during the next 50 minutes. At that time, a sample containing 98.81% solids was taken and an acid number of 96.07 was obtained. The mixture was cooled to 120.9 ° C for the next hour. This was cooled to 60 ° C with a water bath and discharged. The product is a white solid melted at 27 ° C, with the measurement of solids at 99.69%, acid number 68.32, calculated Mn of the acid number was 821, and density, 9.27 Ib. / gallon (4,208 kg / lt).

Method B The same product as described above in Method A, was produced by loading 55% of the caprolactone, all the dimethyl-ilolpropionic acid, heating the mixture to 117 ° C and then adding the caprolactane balance for 1 hour using the exothermic to compensate for the low temperature of the feeding. Some additional heat inputs were necessary to maintain the temperature at 120-123 ° C, but the reaction did not show the temperature increase exhibited by all caprolactone loads once. At the end of the caprolactone feed, the solids were 98.16 and the acid number is 69.07. An additional hour at 120 ° C raised the solids to 99.86. The acid number of the product was 68.14. The calculated Mn of the acid number was 823.

Method C.

To control the increase in polymerization temperature, the mixture was heated to 105 ° C instead of 115 ° C. The heating went out. This reduced the temperature increase ratio and after 90 minutes the temperature increased to only 116 ° C. At this point the solids were 97.24, the acid number 69.0, and the caprolactone was calculated to be converted to 96.7%. The temperature was maintained for an additional 105 minutes at 117-120 ° C to bring the solids to 99.78% and the acid number to 68.1. The calculated Mn of the acid number was 824.

SYNTHESIS OF THE ENTROPIC POLYESTER ARM This material is a carboxyl-terminated polyester of about 2000 Mn. The inclusion of the n-octanoic acid in a copolymer of caprolactone and the commercial 12-hydroxy-t-eric acid provides the necessary molecular weight control.

The following table (Table 1) lists the materials charged to the reactor to form the Entropic Polyester Arm P: TABLE 1 Parts by Weight Reagent 921.77 12-hydroxystearic acid / stearic acid (portion 5.41 / 1 mole) 100. 95 n-octanoic acid 1474.01 Caprolactone 2.39 methanesulfonic acid 244.80 VM & P NAPHTHA RULE 66.118-145 ° C p.b Sil from Shell Chemical Company The charge was to a reactor adapted with a water separator, stirrer, thermal coupler and a nitrogen inlet. The reaction was carried out at reflux temperature. During 8.5 hours, the reactor temperature increased from 149 ° C to 169 ° C and 43.3 parts of water were removed. The product contained 91.07% solids and the solution had an acid number of 26.15. This corresponds to a Mn of 1954 calculated from the acid number. The theoretical Mn for this load was 2040. The Gardnet Holdt viscosity was X (12.90 Stokes).

Molecular Weight Control of the Polyester Arm Entropic The molecular weight can also be controlled by varying the perfection at which the termination is carried out. This is described in the following tables. The entropic polyester arms Pl, P-2 and P-3 were made using the same reaction method as described above, with the loading as described below in Table 2, and the reaction time and temperatures as described in Table 3 below.

TABLE 2 Loading: Parts by weight Reagent 937.02 12-hydroxystearic acid / stearic acid (portion 5.41 / 1 mole) 1496. 31 Caprolactone 2.43 Methane Phonic 244.80 VM & P NAPHTHA RULE 66.118-145 ° C e.g. Sil from Shell Chemical Company TABLE 3 Variation of Reaction Time and Temperature to Control the Molecular Weight of the Arm of Entropic polyester. Polyester Time Acid Temperature # Mn minute ° C (solids) calculated from acid # P-l 510 146-169 12.36 * 4539 P-2 345 147-159 15.20 3692 P-3 297 148-155 18.73 3011 * This is the low acid number that can be achieved with these raw materials due to the hydroxyl content of the hydroxyl stearic acid is consumed to the acid number.

SYNTHESIS OF THE POLY ESTER / ACRYLIC DISPERSANT THAT CONTAINS BOTH FTALIMIDE GROUPS AND QUATERNARY AMMONIUM GROUPS The above monocarboxylic polyesters were combined with a n-BMA / GMA copolymer (40/60) of about Mn = 3900 and other ingredients to produce the dispersant. Based on this, it is about 1.59 hydroxyl-containing polyester grafts and 3.08 entropic arm grafts at the molecular average.

TABLE 4 Loading: Parts by Weight Reactivo 536.49 BMA / GMA copolymer solution in n-butyl acetate / acet at or ethyl acetate at 45.7% in concentration 14.40 Hexamet ilenoimine 80.00 Phthalimide powder 82.32 Hydroxyl polyester (prepared by the method C above) 414.45 Entropic polyester (prepared above) 210 Propylene glycol methoxy acetate 21.63 40% trimethyl benzyl solution of ammonium hydroxide in methanol The charge was to a reactor adapted with a stirrer, reflux condenser, thermal coupler and a nitrogen inlet. The mixture was heated to 105 to 113 ° C for 5.5 hours. Measurements of molecular weight and chromatography showed that the grafting reactions of the polyesters, phthalimide and hexamethyleneimine to the functional epoxy copolymer were complete.

Benzyl chloride, 32.43 parts, was added to quaternize the tertiary amine formed during the first step of the reaction when hexamethyleneimine was reacted with some of the oxirane groups. After 12.5 hours heating to 108 to 110 ° C, the amine number had a trickle from 6.1 to 1.85. This corresponds to a quaternary nitrogen content of 0.17% (2.3% by weight of quaternary ammonium groups). The benzyl chloride can be consumed as determined by gas chromatography.

DISPERSION OF POLY ESTER / ACRI L I CO DISPERSANT WITH NATURAL GAS SMOKE BLACK PIGMENT EXAMPLE 1 The Raven 5000 Ultra II NATURAL GAS SMOKE pigment from Columbian Chemical Company, 18 parts, was mixed with 30.32 parts of the dispersing solution (prepared above) and 51.68 parts of xylene. This thick mixture was ground for 12 hours is a grinder to produce a dispersion with a viscosity of 310 centipoise when measured with a Brookfield viscometer at 1 rpm using pivot # 1. The viscosity was only slightly lower, 206 centipoise, when measured at 50 rpm indicating that the dispersion does not thin to shear. This shows that the product is an excellent dispersant for the natural gas carbon black as indicated by the low viscosity of the di spers ion.

EXAMPLES 2 TO 4.

Other variations of the preparation described in Example 1 use the high molecular weight entropic arms P-1 and the hydroxyl polyester prepared according to Method C and the acrylic copolymer GMA. These differences are included in Table 5 below, showing the impact of the quaternary ammonium content and the phthalimide content on the viscosity of a natural gas carbon black dispersion.

The viscosity data with the conversion of the # of quaternary ammonium groups to the% of quaternary ammonium nitrogen are given in the following table. The viscosity is in centipoises and is determined with a Brookfield viscometer at 1 rpm using pivot # 1.

Table 5: Viscosity of the Natural Gas Smoke Black Dispersions ** E use of Phthalimide Ftalimide Ftalimide Do not . 10% nitrogen at 0% in the quaternary ammonium group 2A 0.2 22200 2B 0.41 70000 3A 0. 1 3 40000 3 B 0. 3 3 3300 C 0. 3 7 7200 D 0. 4 8 68000 4A 0.00 41200 (comp.) 4B 0.12 3800 4C 0.18 1480 4D 0.32 1100 ** Each of the pigment dispersions contained 18% Raven 5000 Ultra II natural gas carbon black from Columbian Chemicals Co. at a dispersant to pigment ratio of 101.8 / 100 using xylene as the solvent and grinding for 12 hours. time in a grinder. 4A is a comparative example of US 5, 24, 364.

A graph made using the data in Table 5 is shown in Figure 1.

EXAMPLE 5 The following table shows the pigment dispersions made in accordance with Example 1 using pigments other than natural gas carbon black. The coagulation ratio is determined for each pigment dispersion.

Pigment Coefficient Manufacturing Evaluation Code Iron oxide Bayferrox 3920 0.5 yellow Vanadium oxide Irgacolor Yellow bismuth Iron oxide Sicotrans Transparent network Dioxide R706 Titanium Quinacr idona Monastral Red Y red Quinacridone Magenta RT-355D magenta Benc imidazolone Hostaperm Yellow a zo Perylene brown Perrindo Maroon 0 Pirrolopirrolo Irgazin DDPRed 0 di keto BO Quinacridone Violet RT-101D violet Ftalo copper Irgazin Blue X 0 blue Ftalo copper Sunfast Green 7 1.5 green Ftalo copper Enduroftal Blue 0 blue Ftalo copper Irgazin Blue ATC 0 blue 3367 * 0 is without flocculation. 3 is completely flocculated as determined by microscopic examination at 200 up to 400x. This test consists of adding to a small bottle of metal stopper with thread 1 gram of solids of the dispersant of Example 1, 2.0 grams of pigment, 20 grams of buryl acetate and 15 grams of glass beads of 0.5-1.0 mm and placing the bottle in a paint shaking device to form a dispersion. The bottle is stirred for 15-20 minutes and then the resulting dispersion is examined. The best dispersions have the lowest ratio with 3 being unacceptable. All the above dispersions made with the dispersant of Example 1 are acceptable.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property.

Claims (15)

Claims

1. A polymeric pigment dispersant, characterized in that it comprises a graft polymer having an acrylic polymer column and slope of the column, polyester side chains, cyclic imide groups and quaternary ammonium groups, and the polymer has an average molecular weight in calculated number of 8,000-50,000; in. wherein the graft copolymer consists essentially of (a) 10-50% by weight of the graft polymer, of an acrylic copolymer column having a number average molecular weight of 2,500-10,000 which, prior to the reaction, contains 25-75% by weight of the polymerized oxirane containing monomers; (b) 20-85%, by weight of the graft polymer, of a polyester copolymer, or a mixture of different polyester copolymers, having a number average molecular weight of 500-10,000 whose polyester copolymer is carboxylic acid functional and adheres to the column by a reaction of the carboxylic acid functional group with an oxirane group on the column; (c) 1-16%, by weight of the graft polymer, of cyclic imide groups adhered to the column by a reaction of the imide group with the oxirane group of the column and (d) 0.2-17% by weight of the graft polymer, of quaternary ammonium groups.

2. The dispersant according to claim 1, characterized in that, in addition, it comprises a mixture of a hydroxy functional polyester copolymer and a second non-hydroxy functional polyester copolymer.

3. The dispersant according to claim 1, characterized in that the oxirane-containing monomers of the acrylic copolymer column comprise either glycidyl acrylate or glycidyl methacrylate.

4. The dispersant according to claim 3, characterized in that, in addition, it comprises a hydroxy functionality in the acrylic copolymer.

5. The dispersant according to claim 1, characterized in that the polyester copolymer comprises polymerized monomer units of a lactone.

6. The dispersant according to claim 1, characterized in that the polyester copolymer comprises monomeric units of a saturated or unsaturated fatty acid or a hydroxy-functional aliphatic acid.

7. The dispersant according to claim 2, characterized in that the hydroxy functional polyester copolymer is the product of the esterification of caprolactone and a hydroxy functional aliphatic acid and the second polyester copolymer of the caprolactone esterification product. and a saturated aliphatic carboxylic acid and an unsaturated carboxylic acid.

8. The dispersant according to claim 1, characterized in that the polyester copolymer is the esterif ication product of lauric acid and caprolatone.

9. The dispersant according to claim 1, characterized in that the polyester is the reaction product of a mixture comprising monomer containing cyclic anhydride, epoxide-containing monomer, and lactone-containing monomers.

10. The dispersant according to claim 1, characterized in that the cyclic imide is selected from the group consisting of phthalimide, saccharin, and maleimide, or mixtures of the same.

11. The dispersant according to claim 1, characterized in that the quaternary ammonium groups are formed by reacting a tertiary amine containing a carboxyl functionality with the oxirane group of the column and forming a quaternary ammonium group by reacting with an aryl halide, aromatic sulfonate, alkyl sulfate or an alkane sultone.

12. The dispersant according to claim 1, characterized in that the quaternary ammonium group is formed by reacting a compound having a quaternary ammonium group and a carboxyl functionality with the oxirane group of the column.

13. The dispersant according to claim 1, characterized in that the quaternary ammonium group is formed by reacting a secondary amine with the oxirane group of the column and forming a quaternary ammonium groups by reacting with benzyl chloride, aromatic sulfonate, alkyl sulfate or a alkane sultone.

14. A dispersion of a pigment using the pigment dispersion of claim 1.

15. A method for making a dispersant, characterized in that it comprises a graft polymer having a calculated number average molecular weight of 8,000-50,000 and has an acrylic polymer column and slope of the column, polyester side chains, cyclic imide groups and groups of quaternary ammonium comprising simultaneously reacting: (a) from 10-50% by weight of the graft polymer, from an acrylic copolymer column having a number average molecular weight of 2,500-10,000 which, before the reaction, contains 25-75% by weight of the polymerized oxirane containing monomers; (b), 20-85%, by weight of the graft polymer, of a polyester copolymer, or a mixture of different polyester copolymers, having a number average molecular weight of 500-10,000 whose polyester copolymer is acid functional carboxylic; (c) 1-16% by weight of the graft polymer, cyclic imide groups and (d) 0.2-17% by weight of the graft polymer, of quaternary ammonium groups, and subsequently quaternizing the precursor to form a quaternary ammonium group. Summary of the Invention Disclosed is a polymeric pigment dispersant of a graft polymer having an acrylic polymer column and polyester side chains pendant to the column, cyclic imide groups and quaternary ammonium groups, and the polymer has a calculated number average molecular weight of 8,000-50,000; wherein the graft copolymer is composed of (a) 10-50% by weight of the graft polymer, of an acrylic copolymer column having a number average molecular weight of 2,500-10,000 which, before the reaction, contains 25-75% by weight of the polymerized oxirane containing monomers; (b) 20-85%, by weight of the graft polymer, of a polyester copolymer, or a mixture of different polyester copolymers, having a number average molecular weight of 500-10,000 whose polyester copolymer is carboxylic acid functional and adheres to the column by a reaction of the carboxylic acid functional group with an oxirane group on the column; (c) 1-16%, by weight of the graft polymer, of cyclic imide groups adhered to the column by a reaction of the imide group with the oxirane group of the column and (d) 0.2-17% by weight of the graft polymer, of quaternary ammonium groups.