MXPA98008173A - Absorbent polymers that have a reduced trend at the entort - Google Patents

Abstract

The present invention provides water-swellable polymeric compositions which have reduced tendencies to tackling. These polymer compositions can be produced by the use of quaternary ammonium salts. In addition to having reduced tendencies to tack, these polymers have a reduced powder, and substantially maintain or increase the surface tension of an aqueous fluid in equilibrium with the polymer and the ai

Description

ABSORBENT POLYMERS THAT HAVE A REDUCED TREND TO THE ENTORTADO DESCRIPTION OF THE INVENTION This invention relates to absorbent polymers whose particles have a reduced tendency to agglomerate in moist environments and / or to form powder, to a process for the preparation of these polymers, and to absorbent articles prepared therefrom. Absorbent, ie water-swellable, polymers are generally prepared by gel polymerization of a monomer mixture in aqueous solution. Certain additives, such as crosslinking agents, can be incorporated into the monomer mixture. The product of the polymerization process is then typically dried and subjected to a mechanical particle size reduction element. Absorbent polymers are especially useful in many types of personal care devices, such as diapers, adult incontinence articles, sanitary napkins, and medical devices, because of their ability to readily absorb bodily fluids. Unfortunately, absorbent polymers also absorb water from the air, and when exposed to humid environments, water-swellable polymer particles tend to adhere to each other, that is, to agglomerate or get stuck, and also tend to stick or adhere to the equipment. of processing. Therefore, the polymer particles are not free flowing, that is, they have a poor possibility of flow. If the polymer particles are not free-flowing, then they present a few problems. One problem is that the particles are difficult to incorporate into personal care devices, because the possibility of reduced flow hinders the uniform distribution of the particles within an absorbent core. Another problem arises from the tendency of the particles to adhere to each other and to the manufacturing, and processing equipment, ie, meshes, dryers, meters, or manufacturing machinery. Production is often hampered because the equipment must be cleaned periodically to remove the agglomerated particles. Yet another problem associated with water swellable polymer particles which tend to agglomerate, is that if the polymer particles have already absorbed some water, then the water swelling capacity for the personal care devices containing such water can be reduced. polymer particles. One way in which the tendencies to the packing of the absorbent polymers have been reduced, is by means of the mixture of finely divided silica or vaporized silica with the absorbent polymeric particles. See, for example, U.S. Patent Number 4,734,478, which mixes 0.01 to 10 parts by weight finely divided silica with 100 parts by weight of the water absorbent polymer, and International Patent Publication Number WO 94/22940, which mixes less than 10 weight percent of vaporized silica with the water absorbing polymer. Unfortunately, even when the tendency to get stuck in polymer particles can be reduced, both types of silica are low volume density solids, and tend to add dust to the environment. Other compounds have been used to reduce the adhesion tendency of the absorbent polymeric particles. Among these are the nonionic or anionic surfactants. See U.S. Patent No. 4,286,082, which utilizes the above surfactants in the presence of a crosslinkable monomer to decrease adhesion of the hydrous polymer to the polymerization vessel. These surfactants can actually reduce the adhesion tendency of the polymer, but the surfactants also reduce the surface tension of a contact fluid in equilibrium with the polymer. This is unfortunate, because the surface tension of the contact fluid is used as a measure of the operation of the water-swellable polymers. The surface tension of the contact fluid in equilibrium is used as a measure of the operation, because water-swellable polymers exhibiting a higher surface tension generally tend to "form a better wick, that is, the polymer transports aqueous fluids more efficiently through capillary flow and contains the fluids more strongly. As described in U.S. Patent No. 5,352,711, wicking is very important for absorbent devices such as diapers or sanitary articles.The effect of surface tension on capillary flow and capillary pressure is described more completely by the Lucas-Washburn equation, as discussed in PK Chatterjee, "Absorbency", Elsevier, Amsterdam, 1985, pages 36-37 Industry would find a great advantage in a water-swellable polymeric composition that would not agglomerate when exposed to a humid environment, that is, comprising more than 90 percent free-flowing polymer particles, edited by the test described herein. The industry would also find advantage in a new process for reducing the agglomeration tendencies of a polymeric water-absorbent composition, which would include using liquid anti-lint agents instead of solids, such as silica, which can increase the powder present. The industry would also find an advantage if these liquid anti-packing agents substantially maintain or increase the surface tension of a contact liquid in equilibrium with the polymer composition. According to the above, in one aspect, the present invention provides a composition comprising: a) lightly cross-linked water insoluble polymer particles, water absorbers; b) an effective amount of an agent against the stuck; and optionally c) a hydrophobic or hydrophilic dedusting agent.

These compositions comprise more than 75 percent, preferably more than 90 percent, and most preferably more than 95 percent, and more preferably more than 99 percent of polymer particles that do not get stuck, as measured by the test described herein . In another aspect, the present invention also provides a process comprising: a) preparing a water-swellable hydrogel by a gel polymerization process; b) drying and preparing the hydrogel prepared in this way to obtain a composition comprising dried and prepared particles; and c) contacting the composition with an effective amount of an agent against the stuck. Quaternary ammonium salts have been used in conjunction with absorbent gels as a lubricant, for example, in U.S. Patent No. 4,997,714, but hitherto, they have not been employed as anti-luting agents. As used in the present invention, the term "substantially maintain or increase surface tension" means that, when an aqueous fluid is in equilibrium with another fluid, and the water-swellable, crush-resistant polymers treated with a dedusting agent hydrophobic of the present invention, the surface tension of the aqueous fluid, measured by a surface tension test described hereinafter, decreases by less than about 10 percent, preferably less than about 5 percent, when compared with the Water-swellable polymers that do not come in contact with a hydrophobic dedusting agent. More specifically, the aqueous fluid employed in the surface tension test described herein is a 0.9 percent NaCl solution, and the other fluid is air. As used herein, the term "dissociated powder" means the measurable portion of a water-absorbent polymer particle composition having a maximum diameter of less than or equal to microns, the portion of which becomes aerial when air is applied to the composition. More specifically, air is applied and the portion is measured using a pulsed jet disperser described below. As used in the present invention, the term "physical coating" means that a coating of the antidust agent and the dedusting agent (if present) in contact with the polymer particles and the powder (if present), does not react With the polymer alone, for example, there is no covalent surface cross-linking reaction between the anti-fouling agent and the polymer particles or the powder. As used in the present invention, the term "Aliphatic hydrocarbon" includes straight or branched chain alkyl, alkenyl, and alkynyl groups, which may have bonds such as silicon (-Si-) or oxygen (-O-) within the chain. The aliphatic hydrocarbons may be unsubstituted or substituted by substituents and nets.

As used in the present invention, the term "aryl group" includes fused aromatic rings such as phenyl, naphthyl, phenanthryl, and anthracenyl, which are unsubstituted or substituted by inert substituents. As used in the present invention, the term "inert substituent" means a substituent that is inert, ie, does not react to its environment. The environment in which the substituent is inert includes the water absorbing polymeric particles and the aqueous liquid in which it is to be dissolved or dispersed. Inert substituents include, for example, halogen groups such as fluorine, chlorine, and bromine, hydroxy groups, and alkoxy groups. The water-swellable or slightly cross-linked hydrophilic polymers that can be used in the present invention can be any of the known hydrophilic polymers that are capable of absorbing large amounts of fluids. In particular, water absorbent polymers useful in this invention are water absorbing polymers containing carboxyl moieties. Preferably, at least 0.01 equivalents of carboxyl groups per 100 grams of the water-absorbent resin are present. Among the preferred carboxyl-containing water-absorbent polymers are the hydrolysates of starch-acrylonitrile graft copolymers, partially neutralized products of starch-acrylic acid graft copolymers or polyvinyl starch-alcohol, vinyl acetate copolymer saponification products- acrylic ester, derivatives of isobutylene and maleic anhydride copolymers, hydrolysates of acrylonitrile copolymers, crosslinked products of hydrolysates of acrylonitrile copolymers, crosslinked carboxymethyl cellulose, hydrolysates of acrylic amide copolymers, crosslinked products of hydrolysates of acrylic amide copolymers, partially neutralized polyacrylic acids, and crosslinked products of partially neutralized polyacrylic acids. Examples of some suitable polymers and processes, including gel polymerization processes, for preparing them, are described in U.S. Patent Nos. 3,997,484; 3,926,891; 3,935,099; 4,090,013; 4,093,776; 4,340,706; 4,446,261; 4,683,274; 4,459,396; 4,708,997; 4,076, 663; and 4, 190,562. These hydrophilic polymers can be prepared from monomers from water-soluble α, β-ethylenically unsaturated monomers, such as monocarboxylic acids, polycarboxylic acids, acrylic amide, and their derivatives. Suitable α, β-ethylenically unsaturated monomers include, for example, acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, and alkali metal salts and ammonium salts thereof; itaconic acid, acrylic amide, methacrylic amide, and 2-acrylamido-2-methyl-1-propanesulfonic acid and its salts. Preferred monomers include acrylic acid and methacrylic acid, and their respective salt forms, such as alkali metal or ammonium salts.

The water-soluble monomers useful in the present invention can be used in amounts of 10 percent to 80 percent by weight, based on the total weight of the aqueous monomer solution. Preferably, the amount is from 15 percent to 60 percent, based on the total weight of the aqueous monomer solution. Optionally, there may be minor amounts of other water-soluble unsaturated monomers, such as alkyl esters of acid monomers, for example, methyl acrylate or methyl methacrylate, in the water-absorbent polymer. In addition, certain graft polymers, such as, for example, polyvinyl alcohol, starch, and water soluble or water swellable cellulose ethers, can be used to prepare products having superior properties. These graft polymers, when used, are used in amounts up to about 10 weight percent, based on the α, β-ethylenically unsaturated monomer. In addition, it may be convenient to include a chelating agent to remove the trace metals from the solution, for example, when a metal reaction vessel is used. A chelating agent is VERSENEXMR V-80 (registered trademark of The Dow Chemical Company), an aqueous solution of the pentasodic salt of diethylene triamine pentaacetic acid. These chelating agents, when used, are generally used in amounts between 100 and 2000 ppm, based on the α, β-ethylenically unsaturated monomer. It is desirable to obtain a conversion level of the monomer to the polymer of at least about 95 percent. The polymerization can be carried out using acidic monomers that are not neutralized or that have been neutralized or partially neutralized prior to polymerization. The neutralization is conveniently achieved by contacting the aqueous monomer with an amount of basic material sufficient to neutralize between 20 and 95 percent of the acid groups present in the acidic monomers. Preferably, the amount of basic material will be sufficient to neutralize between 40 percent and 85 percent, and more preferably between 55 percent and 75 percent of the acid groups present in the acidic monomers. When the monomeric solution is previously neutralized, it is important to control the neutralization conditions, so that the heat of the neutralization does not cause the premature polymerization of the monomer mixture. It conveniently neutralizes it at temperatures below 40 ° C, preferably at temperatures below 35 ° C. The compounds which are useful for neutralizing the acid groups of the monomers are typically those which sufficiently neutralize the acid groups without having a detrimental effect on the polymerization process. These compounds include alkali metal hydroxides, and alkali metal carbonates and bicarbonates. Preferably, the material used to neutralize the monomer is a sodium or potassium hydroxide or carbonate. In determining the desired degree of neutralization, care must be taken to ensure that the pH of the resulting cross-linked absorbent polymer, which will contact with, or will disperse in, an aqueous fluid to be absorbed, is maintained in a appropriate range for the applications for which the polymer is intended. Alternatively, the polymerization can be carried out using unneutralized monomers, and subsequently neutralized, as is known in the art. Conveniently, a conventional vinyl addition polymerization initiator is used in the polymerization of the water soluble monomers and the crosslinking agent. A free radical polymerization initiator that is sufficiently soluble in the monomer solution to initiate the polymerization is preferred. For example, water-soluble persulfates such as potassium persulfate can be used, ammonium persulfate, sodium persulfate, and other alkali metal persulfates, hydrogen peroxide, and water-soluble azo compounds such as 2,2'-azobis (2-amidinopropane "HCl). Some of these initiators, such as hydrogen peroxide, can be combined with reducing substances such as sulfites or amines, to form known reduction-oxidation initiator systems. The total amount of initiators used may be 0.01 to 1.0 percent by weight, preferably 0.01 to 0.5 percent by weight, based on the total weight of the α, β-ethylenically unsaturated monomer reagents. The water-absorbent resin will preferably be lightly cross-linked to make it insoluble in water and water-swellable. The desired crosslinked structure can be obtained by the copolymerization of the selected water-soluble monomer and a crosslinking agent possessing at least two polymerizable double bonds in the molecular unit. The crosslinking agent is present in an amount effective to crosslink the water soluble polymer. The preferred amount of crosslinking agent is determined by the desired degree of absorption capacity and the desired strength to retain the absorbed fluid, i.e., the desired absorption under load (AUL). Typically, the crosslinking agent is used in amounts of 0.0005 to 5 parts by weight per 100 parts by weight of the α, β-ethylenically unsaturated monomer used. More preferably, the amount is 0.1 to 1 parts by weight per 100 parts by weight of the α, β-ethylenically unsaturated monomer. Usually, if an amount greater than about 5 parts by weight of crosslinking agent is used per 100 parts, the resulting polymer has a too high crosslink density, and exhibits a reduced absorption capacity and a greater strength to retain the absorbed fluid. If the crosslinking agent is used in an amount of less than about 0.0005 parts by weight per 100 parts, the polymer normally has too low a crosslink density, and when it comes into contact with the fluid to be absorbed, it becomes sticky , and exhibits a lower initial absorption speed. Although the crosslinking agent will typically be soluble in the aqueous solution of the α, β-ethylenically unsaturated monomer, the crosslinking agent may be merely dispersible in that solution, without negative implications. The use of these dispersing agents is described in United States Patent Number 4,833,222. Suitable dispersing agents are suspension auxiliaries of carboxymethyl cellulose, methyl cellulose, hydroxypropyl cellulose, and polyvinyl alcohol. These dispersing agents are typically provided in a concentration between 0.005 and 0.1 weight percent, based on the total weight of the α, β-ethylenically unsaturated monomer reagents. Typical crosslinking agents include monomers having one molecule, from two to four groups selected from CH2 = CHCO-, CH2 = C (CH3) CO- and CH2 = CH-CH2. Exemplary crosslinking agents are diacrylates and dimethacrylates of ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, and pentaerythritol; triacrylates and trimethacrylates of trimethylolpropane and pentaerythritol; highly ethoxylated trimethylolpropane triacrylate; pentaerythritol tetroacrylate and tetramethacrylate; and tetraalyloxyethane. As noted in International Patent Publication Number WO 93/05080, published on March 18, 1993, certain crosslinking agents give particularly preferred absorbent properties. These preferred crosslinking agents include methylenebisacrylic amide, bis (acrylamido) acetic acid and its salts, allyl acrylate, allyl methacrylate, and esters or amides having both a vinyl functionality and an allyl functionality. Other crosslinking agents and particularly preferred methods include those described in International Patent Publication Number WO 94/20547, published September 15, 1994. These preferred crosslinking agents include mixtures of polyvinyl compounds such as, for example, trimethylolpropane triacrylate. ethoxylated and allyl methacrylate, and polyglycols, such as, for example, polyethylene glycol. In a preferred embodiment for making polymers useful in the practice of this invention, an aqueous solution of the α, β-ethylenically unsaturated monomer is prepared in the partially neutralized form, the crosslinking agent, the initiator, and a polymeric graft substrate, if you want The polymerization of the mixture can be carried out by methods well known to those skilled in the art. The resulting polymer is typically pre-prepared and dried using elements well known in the art. To improve the absorbent properties, the dried particles can be heat treated according to the procedures stipulated in International Patent Publication Number WO 93/05080, published March 18, 1993, and / or in the International Patent Publication Number WO 94/20547, published September 15, 1994. In particular, the dry particles are heated for a sufficient time to increase the modulus, the centrifugal capacity, and / or the absorbency under load. An oxidizing agent, such as a bromate, chlorate, chlorite, or a mixture thereof, may be uniformly distributed within the water-absorbent polymer, prior to heat treatment, to improve one or more of the above properties. This heat treatment is preferably carried out at a temperature of at least 170 ° C, more preferably at least 180 ° C, and most preferably at least 190 ° C. This heat treatment is preferably carried out at a temperature of less than 250 ° C, more preferably less than 240 ° C. The period of time for the heat treatment should be sufficient to effect an improvement in the absorbent properties. The exact times of heat treatment required will be affected by the selected equipment, and can be determined empirically by an examination of the properties of the product. Preferably, the time is at least 3 minutes, and more preferably at least 5 minutes. If the time is too long, the process becomes uneconomical, and there is a risk that the absorbent resin may be damaged. Preferably, the maximum heating time is 1 50 minutes or less, more preferably 60 minutes or less. The heat treatment method is not critical. For example, forced air furnaces, fluidized bed heaters, and heated screw conveyors can be successfully employed. If desired, the heated polymer can be re-moistened for ease of handling. Although this rewetting can serve to decrease the amount of dissociated powder, it can lead to the accumulation of the polymer product. Another way to improve the absorbent properties of the polymer particles, may be the surface crosslinking of the polymer particles. The procedures for surface crosslinking are well known in the art, and are described, for example, in Patent Numbers DE 4244548, DE 4020780, EP 605150, and in Patents of the United States of North America Nos. 4,734,478 and 4,666,983. These processes, such as heat treatment, can increase the modulus, the centrifugal capacity, and / or the absorbency under load of the polymeric particles. The dried, sizing, and optionally heat-treated, or optionally surface-crosslinked polymer particles are then contacted with an effective amount of an anti-fouling agent. It is critical that the polymer particles do not remain in the form of a gel, i.e., that they have less than 30, preferably less than 20, and more preferably less than about 10 weight percent water, before contacting them with the agent against the stuck. If the agent against the insert is brought into contact with the polymer particles in the form of gel, then it is possible that the anti-plug agent is combined with the water and is further absorbed into the polymer particles. If this happens, then the properties against the packing of the particles are reduced, because the agent against the stuck is not on the surface of the particles. It is also critical for this invention that the polymer particles not be subjected to temperatures greater than 100 ° C after the particles are contacted with the agent against being stuck. This is due to the fact that the antifouling agent can vaporize or degrade at higher temperatures. Accordingly, if a drying step and / or a heat treating step are to be undertaken which subject the particles to temperatures above 100 ° C, then the drying and / or heat treatment steps should be carried out before that the particles come in contact with the agent against the stuck. The blocking agent physically covers the polymer particles and serves to decrease the adhesion of the polymer particles to each other and to the machinery or containers with which the polymer particles come into contact. The polymeric particles will not suffer significant decreases in the possibility of flow, nor will they suffer a setback, significant when absorbing moisture. After contact with an effective amount of anti-fouling agent, at least 75, preferably at least 90, more preferably at least 95, and most preferably at least 99 percent of the particles should be non-entangled polymer particles according to the test described in the present one entitled "Test of Entortado". As defined herein, the term "effective amount of agent against thickened" means an amount of a cationic surfactant, for example, a sulfonium, phosphonium, or quaternary ammonium compound which, when applied to polymeric particles, makes which do not settle at least 75, preferably at least 90, more preferably at least 95, and most preferably at least 99 percent of the particles, according to the "Stuck Test". Although this effective amount will vary depending on the polymer, the anti-fouling agent, and the amount of moisture, typically the amount is at least 100, preferably at least 500, and more preferably at least 1000 parts per million anti-jamming agent. , based on the weight of the polymer particles. Typically, this amount is at most 5,000, preferably as much as 4,000, and most preferably as much as 3,000 parts per million agent against packing, based on the weight of the polymer particles. Preferably, the cationic surfactants useful as anti-clumping agents are quaternary ammonium salts which are represented by the formula I: wherein Ri and R3 are independently an aliphatic hydrocarbon of 1 to 22 carbon atoms, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an unsubstituted aryl group, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an aryl group substituted by an aliphatic hydrocarbon of 1 to 22 carbon atoms, or a phenyl group; R2 is an aliphatic hydrocarbon of 1 to 6 carbon atoms or a phenyl group; and R 4 is an aliphatic hydrocarbon of 1 to 22 carbon atoms, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an unsubstituted aryl, or an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an aryl group substituted by a hydrocarbon aliphatic of 1 to 22 carbon atoms, or R4 is a radical represented by formula II: wherein Rs is an alkylene group of 2 to 6 carbon atoms; Rβ is an aliphatic hydrocarbon of 1 to 6 carbon atoms or a phenyl group; R7 and R8 are independently an aliphatic hydrocarbon of 1 to 22 carbon atoms, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an unsubstituted aryl group, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an aryl group substituted by an aliphatic hydrocarbon of 1 to 22 carbon atoms, or a phenyl group; or R2 and R4 taken together with the nitrogen atom, form a ring selected from the group consisting of pyrroiidine, pyrroline, pyrrole, pyrazole, triazole, indole, piperazine, piperidine, morpholine, and hexahydroazepine; or R1 f R2, and R4 taken together, form a ring selected from the group consisting of pyridinium and imidazolinium; and X? it is an anion; with the proviso that, if R4 is not the radical represented by formula II, then the sum of the carbon atoms in R ?, R2, R3, and 4 must be at least 15, and if R4 is the radical represented by formula II, then at least one of R1, R3, R4, and Rβ must have 8 or more carbon atoms. A preferred embodiment is the above formula wherein Rt is an aliphatic hydrocarbon having at least 16 carbon atoms, such as hexadecyl, octadecenyl, octadecyl, docosanyl, docosenyl, and derivatives of natural products such as tallow, soy, and rapeseed.; R2 is an alkyl group having 1 to 2 carbon atoms, such as methyl, ethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2- (2-hydroxyethyloxy) ethyl, or 3- (3-hydroxypropyloxy) propyl; and R3 and R4 are independently an alkyl group having from 1 to 6 carbon atoms, such as methyl, ethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2- (2-hydroxyethyloxy) ethyl, or 3- (3-hydroxypropyloxy) propyl, or an alkyl group having 1 to 4 carbon atoms substituted by a phenyl, such as a benzyl or phenethyl group. Another preferred embodiment is the above formula wherein R ^ and R are independently an aliphatic hydrocarbon having at least 8 carbon atoms, such as octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecenyl, octadecyl, docosanyl, docosenyl, or derivatives thereof. natural products, such as tallow, soy, and rapeseed; R2 is an alkyl group having from 1 to 6 carbon atoms, such as methyl, ethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2- (2-hydroxyethyloxy) ethyl, 3- (3-hydroxypropyloxy) propyl; and R4 is an alkyl group having from 1 to 6 carbon atoms, such as methyl, ethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2- (2-hydroxyethyloxy) ethers, or 3- (3-hydroxypropyloxy) propyl, or an alkyl group having 1 to 4 carbon atoms substituted by a phenyl, such as a benzyl or phenethyl group. Still another preferred embodiment is the above formula wherein R 4 is the radical represented by formula II; R, is an aiiphatic hydrocarbon having at least 8 carbon atoms, such as octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecenyl, octadecyl, docosanyl, docosenyl, or derivatives of natural products such as tallow, soy, and rape seed; R2 and R6 are independently an alkyl group having from 1 to 6 carbon atoms such as methyl, ethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2- (2-hydroxyethyloxy) ethyl, or 3- (3-hydroxypropyloxy) propyl.; R5 is an alkylene of 2 to 6 carbon atoms such as ethylene, propylene, or butylene; and R3, R7, and Rβ are independently an aliphatic hydrocarbon of 1 to 22 carbon atoms, such as; methyl, ethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2- (2-hydroxyethyl) ethyl, or 3- (3-hydroxypropyloxy) propyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecenyl, octadecyl, docosanyl, docosenyl, or derivatives of natural products such as tallow soybean, and rapeseed, or alkyl groups having 1 to 4 carbon atoms substituted by a phenyl, such as benzyl or phenethyl. Preferably X? is a halide, such chloride cone (Cl °) or a methyl sulfate group (MeSO4 °). In order to facilitate the contact of the agent against the stuck with the polymeric particles, it is preferable to use the agent against the stuck in a liquid form. Because the quaternary ammonium salts used as anti-luting agents have relatively low melting points, the anti-luting agent can simply be heated above its melting point to form a liquid, which then is applied to the polymer. However, if heat is used, then the temperature should not rise above the boiling point of the agent against being stuck. For this reason, it may be more preferable to dissolve the agent against the stuck in a solvent that is a liquid at room temperature. Although not required, it may be convenient for the solvent employed to be easily removed from the polymer particles, for example, by evaporation. In this way solvents which can affect the surface tension of an aqueous fluid in equilibrium with the polymer can be removed, and the surface tension can be substantially maintained or increased. Useful solvents include compounds such as water, alcohols, ethers, ketones, and mixtures thereof. A particularly preferred embodiment may be to use the hydrophilic dedusting compounds of International Patent Publication Number WO 94/22940 as solvents. Through the use of hydrophilic compounds of International Patent Publication Number WO 94/22940, such as polyether polyols, as solvents, a compound against threading can be obtained which also has reduced powder. The solvent must be employed in an effective amount to serve as a dedusting agent as defined below. The hydrophilic dedusting composition can be employed in amounts that do not substantially affect the surface tension of an aqueous fluid in equilibrium with the polymer and air, or in greater amounts if the hydrophilic dedusting composition evaporates easily. Another particularly preferred embodiment may be to use hydrophobic compounds as solvents or as cosolvents with the hydrophilic compounds. The hydrophobic compounds described below serve as dedusting agents, while substantially maintaining or increasing the surface tension of an aqueous fluid in equilibrium with the polymer and air. Exemplary hydrophobic compounds often include aliphatic hydrocarbon oils, such as mineral oil, and alkanes or alkenes having from 7 to 18 carbon atoms optionally substituted by -OH, -CO2H, or esters thereof. Natural oils, such as castor oil, corn oil, cottonseed oil, olive oil, rapeseed oil, soybean oil, sunflower oil, and other vegetable and animal oils, as well as esters, alcohols, and the oils are useful in the invention, as well as silicone oils of similar viscosities. When the hydrophobic compounds are used as solvents, they should be employed in an amount effective to serve as a dedusting agent as defined below. If a solvent is used for the material against the stuck that does not also serve as a dedusting agent, or if no solvent is used, then it may be desirable to contact the dry and optionally heat treated or optionally surface treated particles with an effective amount of a dedusting agent. The contact with the dedusting agent can be used before, after, or simultaneously with the anti-fouling agent. The dedusting agent will serve to adhere the powder to the larger polymer particles or to the walls of the mixing vessel where the polymer is retained during handling, which will translate the dissociated powder into the polymer product finished at the different stages of the operation at reduced levels. driving. Moreover, the application of the dedusting agent to the polymer samples does not affect the operation or properties of the polymer. Useful dedusting agents are hydrophilic compounds such as those described in International Patent Publication Number WO 94/22940, for example, polyether polyols, and hydrophobic compounds such as aliphatic hydrocarbon oils, such as mineral oil, and alkanes or alkenes which have between 7 and 18 carbon atoms optionally substituted by -OH, -C02H, or esters thereof. Natural oils such as castor oil, corn oil, cottonseed oil, olive oil, rapeseed oil, soybean oil, sunflower oil, other vegetable and animal oils, as well as esters, alcohols, and acid oils , are useful, as well as silicone oils of similar viscosities. The above compounds can be used in a purified form, in solutions, or in mixtures. As defined herein, the term "effective amount of a dedusting agent" or "effective amount to serve as a dedusting agent" means an amount of material that, when applied to the polymeric material, reduces the concentration of the dissociated powder that have a diameter of less than 10 microns, by at least 80 microns, preferably at least 90, more preferably by at least 95, and most preferably by at least 99 percent, and / or that produce dusted compositions that comprise less of 7, preferably less than 5, and more preferably less than 2.5 ppm of dissociated powder having a maximum diameter of less than or equal to 10 microns. This amount will vary based on the amount of powder initially present, the type of water absorbing polymer, and the dedusting agent employed. In general, the amount of dedusting agent is at least 100, preferably at least 200, and more preferably at least 300 ppm, based on the weight of the polymer particles. The amount is generally less than 4,000, preferably less than 2,000, more preferably less than 1,000,000, based on the weight of the polymer particles. As mentioned above, if a dedusting agent is to be employed, then polymer particles dried, sizing, and optionally heat treated, or optionally surface crosslinked, can be contacted with the dedusting agent before, after, or simultaneously with the contact with the agent against the stuck. The dedusting agent can also be used as a solvent for the anti-fouling agent. In any case, both the anti-fouling agent and the dedusting agent should be contacted with the polymeric particles under conditions such that the particles can be easily coated with the agents. Preferably, this contact will be conducted by spraying the agents onto the polymer, or by immersing the polymer in the agent, followed by some form of mechanical distribution, such that a suitable distribution of the agents is present on the particles of the absorbent resin of the polymer. Water. If it is sprayed, then it may be preferable to use an air atomizing nozzle, and mix a fluidizing amount of water with the agents to better distribute the agent. Typically, the amount of water is less than 5, preferably less than 4, and more preferably less than 3 weight percent, based on the weight of the agents. The amount of water is greater than 1, preferably greater than 2 weight percent, based on the weight of the agents. Examples of the mixing equipment / process include simple tumbling of a jar, or mixing in a conical dryer, ribbon mixer, drum tumbler, or paddle mixer. A moderate shaking, shaking, or even a short transport distance on a screw conveyor, may be sufficient for that proper distribution of the agent or agents on the particles, particularly if the particles are at an elevated temperature. A moderate grinding will also suffice, but it is not necessary. The type of contact employed may be the same or different for the anti-fouling agent and the dedusting agent if the polymeric particles come into contact with the anti-fouling agent and the dedusting agent at separate times. The contact temperature of the agents can be any temperature at which the agent does not evaporate, solidify, become too viscous, or react in a significant way with the carboxyl moieties of the polymer of the absorbent resin. These temperatures are typically from 20 ° C to 150 ° C, preferably from 20 ° C to 60 ° C. It should be noted that high temperatures, that is, those higher than the ambient temperature, that is, higher than 25 ° C, improve the coating speed of the particles. However, if the temperature used is between 100 ° C and 150 ° C, then the contact time should not be so long that agents degrade. Typically, if the temperature remains elevated for less than 5 minutes, preferably less than 3 minutes, no significant degradation will occur. The superabsorbent polymers of this invention are useful in the manufacture of moisture absorbing articles, such as disposable diapers, sanitary napkins, incontinence clothing, and bandages. The superabsorbent compositions of the present invention are particularly useful in the manufacture of thin and ultra-thin disposable diapers having excellent moisture absorbency, fluid distribution properties, and reduced leakage. The absorbent particles of the present invention may comprise from 5 percent to 95 percent by weight of the superabsorbent polymers of the present invention. In a typical absorbent article, the superabsorbent polymer of the present invention can be dispersed in a fiber matrix where the superabsorbent is present in an amount of 30 to 70 weight percent, and comprising the fiber matrix 70 to 30 percent by weight. percent in weight of the article. In another form of absorbent article, the superabsorbent may be present in a containment structure wherein the superabsorbent polymer is present in an amount of 30 to 95 weight percent. Also known are combinations of dispersed superabsorbent polymer and contained superabsorbent polymer. The superabsorbent polymers of this invention can be used in the manufacture of absorbent articles, such as those described in U.S. Patent Nos. 3,669,103; 3,670,731; 4,654,039; 4,699,823 4,430,086; 4,973,325; 4,892,598; 4,798,603; 4,500,315; 4,596,567 4,676,784; 4,938,756; 4,537,590; 4, 935; 022; 4,673,402; 5,061,259 5,147,343; 5, 149, 335; and 5,156,902. The process used to measure the amount of stuck to a particular moisture level is called the "Stuck Test". The use of this test allows to determine the effectiveness of an agent against the stuck, by determining the amount of moisture that a sample can absorb, and still be free fiow. The test involves placing a desiccator, for example, a Cole-Parmer, Catalog Number G-08904-00, in an oven. The desiccator is kept at 80 percent humidity by placing a straight-sided evaporator plate, containing a saturated solution of potassium bromide inside the desiccator. The oven is maintained at 40 ° C. Samples of 5 grams of each dried superabsorbent polymer are placed, ie, with less than 5 weight percent of water, to be tested, in an aluminum foil tray or in a plastic dish measuring 6 centimeters in diameter. diameter 1.5 centimeters deep. The tray is removed from the desiccator after a sufficient amount of time for the samples to reach the desired moisture level to be tested. Samples are weighed to determine the mass of moisture, and then allowed to cool to room temperature. While stirring lightly, for example, by lightly tapping, the sample is sifted through a standard test screen of E. U.A No. 8 (2.36 millimeters). The amount passing through the sieve is weighted to determine the mass of the polymer particles that do not get stuck. The percentage of particles that do not get stuck is then determined by the following formula: percentage that does not get stuck = (mass of polymer particles that do not get stuck / wet mass (x 100) .The humidity level can be determined in percentage by the following formula [(wet mass - initial sample weight) / initial sample weight]] x 100. The "Dust Test", that is, the process to measure the amount of dissociated powder that has a smaller diameter than a previously determined size present in a water-swellable polymer composition is described below. In the case of the examples, the measurement process was used to determine the amount of dissociated matter that had a maximum size of less than or equal to 10 microns. However, the process is applicable to measure the amount of dissociated powder having a smaller diameter than other previously determined sizes, the previously determined sizes being typically consistent with the manufacturer's or buyer's specifications. The process comprises: (a) placing the composition in the sample holder of a pulsed jet disperser; (b) blasting the composition with dry air by passing it through a dewatering element; and (c) determining the weight of the particles in each of a plurality of size increments. The dewatering elements are suitable for reducing the amount of water present in the air to be used to blast the polymeric composition. Suitable dehydration elements include molecular sieve cartridges, desiccant materials, and membranes. An especially preferred dehydration element is a molecular sieve cartridge. The powder levels of the coated samples can be measured as follows. Approximately 0.01 to 0.2 grams of the sample to be tested are placed in the sample holder of a pulsed jet disperser, for example, an AEROSIZERMR available from Amherst Process Instruments (Hadley, Massachusetts). The impulse jet disperser is adjusted with a mesh of 250 microns to prevent particles greater than 250 microns in diameter from entering the detector. The air applied to the pulse jet disperser is filtered using the filter supplied at the factory, and dried using a molecular sieve cartridge. The samples are dripped with the dry air, the extraction current being directed to the detector, and analyzed until the instantaneous counting rate decays to less than 20 particles per second in the detector's low sensitivity position. Measurements are made on separate portions of the samples, and averaged. For each portion, a determination is made of the total number of particles in each of 500 uniformly distributed size increments logarithmically from 0.2 to 200 microns, the instrument exhibiting an approximate lower detection level of 0.5 microns. The weight of the material in each of these size increments is calculated using the following equation: Weight = (number of particles in an increase) (density). { %) (particle diameter, 3/6.

For sodium polyacrylate superabsorbent materials, the density of 1.60 grams / cubic centimeter is assumed. The aggregate weight of the dissociated material less than 10 microns is designated as pesop? | V0. This weight is compared to the weight of the sample originally introduced into the disperser, that is, the weight of the sample. The percentage of dust is determined according to the following equation: Percent by weight of powder (%) = 100 (pesop ??? O) / (pesomue »tra) The "Surface Tension Test" uses a Du Noüy tensiometer, for example, a Krüss K12MR Process Tester. The preparation of an aqueous fluid to be measured, in equilibrium with the absorbent polymer and air, has been substantially adapted from U.S. Patent Number 4,654,039. One gram of extracts from each of the above absorbent polymers, i.e., the control absorbent polymer (untreated) and the absorbent polymer treated with hydrophobic dedusting agents, is stirred with 200 grams of a 0.9 percent NaCl solution. weight, to simulate a urine solution. Then the surface tension is measured with the tensiometer.

Example I A test was conducted to examine the percentage of non-clumped, the level of moisture in percent, and the dusty, of water-swellable polymers, and the surface tension of a liquid in contact with these polymers. A water swellable polymer that had dried to about 5 percent moisture was obtained. The polymer was DRYTECHMR 2035 superabsorbent (available from The Dow Chemical Company) a heat treated 62 percent neutralized polyacrylate. A predetermined amount of agent was added by dripping against the stuck, as shown in Table I, dissolved in isopropyl alcohol, except where indicated, at our polymer at 25 ° C. Then the coated particles were laminated for 60 minutes to distribute the agent on the surfaces of the particles. The percentage of not stuck and the humidity level (in percentage) during the Stress Test, were measured as described in the previous Stress Test. The amount of powder of less than 10 microns was measured as described in the previous Powder Test. The surface tension was measured as described in the previous Surface Tension Test. The results with respect to each sample are stipulated in Table I. Table IA describes the surfactants used as anti-fouling agents exemplified in Table I. ARQUADMR and ETHOQUADMR are registered trademarks of Akzo Nobel Chemicals Inc. Kenam ineMR is a trademark registered commercial of Humko Chemical Division, Witco Corporation. cp co TABLE IA DESCRIPTION OF QUATERNARIAN TENSOACTIVOS MOMBKB BaX MOOOCXO NAME C HDI BK XBmOACXZVO CUMSRM? JUO • D Arquad "2 £ -75 Chloride d * as a quaternary di (coalkalkyl) di-net ionic < 2) I hoquad * T / 12-75 Aconite Chloride Seboalkyl "ethyl-di (2-hydroxyßtllic) 3) EtboquadP 0/12 Aconite Chloride oleylmethyldi (2-hydroxyethyl) (4) Arquad * 12-23 Dodecyltrinetilic Acid Chloride (S) Arquad "15-50 Hexadecyltrimethyl Acid Chloride < «) Arquad" ls-50 octaneciltrimetilic aerm chloride (7) Arquad * S-SO iaoalkyltriaethyl amide chloride (8) Kanaaine '* ft-29ß3-C Ethyl eruciltri ammonium chloride < * > Arquad "12-37W dodecyltrimethyl Ammonium Chloride (10) Arquad "T-27W ammonium chloride seboalquiltrimetllico Example II A test was conducted to examine the percentage of non-clumped, the level of moisture in percent, and the dustiness of water-swellable polymers, and the surface tension of a liquid in contact with these polymers. A water swellable polymer that had dried to about 5 percent moisture was obtained. The polymer was superabsorbent DRYTECHMR 2035 (available from The Dow Chemical Company), a neutralized polyacrylate at 62 percent, heat treated. The polymer was heated to 50 ° C in a batch mix, double-arrowed 3-liter, with rotary counter. Agitation was initiated, and a predetermined amount of agent was sprayed against the tackifier and / or dedusting agent, as shown in Table II, with the anti-fouling agent being dissolved in the dedusting agent, except where indicated, on the polymer , using an air atomization nozzle. Agitation was continued until the mixture was no longer cohesive, from 2 to 15 minutes. The percentage of not stuck and the humidity level in percentage, are measured as described in the previous Test of Entortado. The amount of powder less than 10 microns was measured as described in the previous Powder Test. The surface tension was measured, as described in the previous Surface Tension Test. The results with respect to each sample are stipulated in Table II. In Table II, Q9702-C represents KenamineM R Q9702-C, Q2802C represents Kenamine .M "" R "2802-C, Voranol represents Voranol 2070MR, polyether polyol available from The Dow Chemical Company, and" MO "represents mineral oil .

The absorbent polymers against the binder of the examples exhibit centrifugal capacities and absorbencies under load (AUL) similar to the untreated absorbent polymers. In view of the description and examples, a person skilled in the art will easily assert other modalities. In accordance with the foregoing, the scope of the invention will be limited only by the claims stipulated below.

Claims (6)

1. A non-dusting, anti-stick composition, which comprises: a) lightly cross-linked water insoluble polymer particles, water absorbers; b) an effective amount of an agent against the cationic surfactant entrainer; and c) from 100 ppm to 6,000 ppm, based on the weight of the polymer particles, of a hydrophilic dedusting agent.

2. A non-dusting, anti-stick composition, which comprises: a) lightly cross-linked water insoluble polymer particles, water absorbers; b) an effective amount of an agent against the cationic surface active agent; and c) from 100 ppm to 3,000 ppm, based on the weight of the polymer particles, of a hydrophilic dedusting agent. The composition of claims 1 or 2, wherein the anti-clustering agent is represented by formula I: R, Xe (I) wherein R ", and R3 are independently an aliphatic hydrocarbon of 1 to 22 carbon atoms, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an unsubstituted aryl group, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an aryl group substituted by an aliphatic hydrocarbon of 1 to 22 carbon atoms, or a phenyl group; R2 is an aliphatic hydrocarbon of 1 to 6 carbon atoms or a phenyl group; and R 4 is an aliphatic hydrocarbon of 1 to 22 carbon atoms, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an unsubstituted aryl, or an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an aryl group substituted by a hydrocarbon aliphatic of 1 to 22 carbon atoms, or R is a radical represented by formula II: wherein R5 is an alkylene group of 2 to 6 carbon atoms; R6 is an aliphatic hydrocarbon of 1 to 6 carbon atoms or a phenyl group; R7 and R8 are independently an aliphatic hydrocarbon of 1 to 22 carbon atoms, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an unsubstituted aryl group, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an aryl group substituted by an aliphatic hydrocarbon of 1 to 22 carbon atoms, or a phenyl group; or R2 and R4 taken together with the nitrogen atom, form a ring selected from the group consisting of pyrrolidine, pyrroline, pyrrole, pyrazole, triazole, indole, piperazine, piperidine, morpholine, and hexahydroazepine; or R1 t R2, and R4 taken together, form a ring selected from the group consisting of pyridinium and imidazoiumium; and X? it is an anion; with the proviso that, if R4 is not the radical represented by formula II, then fa sum of the carbon atoms in Ri, R2 and R3, and R4 must be at least 15, and if R4 is the radical represented by Formula II, then at least one of R < , R3, R7, and R8 must have 8 or more carbon atoms. 4. The composition according to any of the preceding claims, wherein the anti-stick agent is di-tallow hydrogenated-dimethyl ammonium chloride. The composition according to any of the preceding claims, wherein the composition comprises: a) lightly crosslinked, water-absorbable, water-insoluble polymer particles; b) from 60 ppm to 150 ppm, based on the weight of the polymeric particles, of hydrogenated di-tallow ammonium dioxide-diene; and c) from 400 ppm to 600 ppm, based on the weight of the polymer particles, of a polyether polyol. 6. An absorbent article prepared from the composition according to claim 1 or 2. A process comprising: a) preparing a water-swellable hydrogel by a gel polymerization process; b) drying and preparing the hydrogel prepared in this way to obtain a composition comprising dried and prepared particles; and c) contacting the composition with an effective amount of an agent against the cationic surfactant and from 100 ppm to 6., 000 ppm of a hydrophobic dedusting agent, under conditions sufficient to physically cover the particles with the anti-fouling agent and the dedusting agent. 8. The process according to claim 7, wherein the composition is heat treated prior to contacting the composition with the antitocking agent. 9. The process according to any of the preceding claims, wherein the agent against the skeleton is represented by the formula I: where R < and R3 are independently an aliphatic hydrocarbon of 1 to 22 carbon atoms, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an unsubstituted aryl group, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an aryl group substituted by an aliphatic hydrocarbon of 1 to 22 carbon atoms, or a phenyl group; R is an aliphatic hydrocarbon of 1 to 6 carbon atoms or a phenyl group; and R 4 is an aliphatic hydrocarbon of 1 to 22 carbon atoms, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an unsubstituted aryl, or an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an aryl group substituted by a hydrocarbon aliphatic of 1 to 22 carbon atoms, or R4 is a radical represented by formula II: wherein Rs is an alkylene group of 2 to 6 carbon atoms; Rβ is an aliphatic hydrocarbon of 1 to 6 carbon atoms or a phenyl group; R7 and R1 are independently an aliphatic hydrocarbon of 1 to 22 carbon atoms, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an unsubstituted aryl group, an aliphatic hydrocarbon of 1 to 4 carbon atoms substituted by an aryl group substituted by an aliphatic hydrocarbon of 1 to 22 carbon atoms, or a phenyl group; or R2 and R4 taken together with the nitrogen atom, form a ring selected from the group consisting of pyrrolidine, pyrroline, pyrrole, pyrazole, triazole, indole, piperazine, piperidine, morpholine, and hexahydroazepine; or R L R2, and R taken together, form a ring selected from the group consisting of pyridinium and imidazolinium; and X? it is an anion; with the proviso that, if R4 is not the radical represented by formula II, then the sum of the carbon atoms in R1 f R2, R3, and R4 must be at least 15, and if R4 is the radical represented by Formula II, then at least one of R «, R3, R, and R8 must have 8 or more carbon atoms. 10. A non-dusting, anti-stick composition that can be obtained by contacting lightly cross-linked water-insoluble polymer particles, water absorbers, with an effective amount of an agent against the cationic surfactant, and at least one of: a) from 100 ppm to 600 ppm, based on the weight of the polymer particles, of a hydrophobic dedusting agent; and b) from 100 ppm to 3,000 ppm, based on the weight of the polymeric particles, of a hydrophilic dedusting agent.