FR2474511A1 - PROCESS FOR THE PRODUCTION OF LATEX BY AQUEOUS EMULSION POLYMERIZATION, EMULSION COMPOSITION, EMULSION POLYMERIZATION PROCESS, AND EMULSIFIER FOR USE - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS FOR THE PRODUCTION OF LATEX BY POLYMERIZATION IN AQUEOUS EMULSION OF ONE OR MORE POLYMERISABLE MONOMERS. ACCORDING TO THE INVENTION, THE POLYMERIZATION IS CARRIED OUT IN THE PRESENCE OF AN AMINE SALT OF POLYURETHANE PREPOLYMER AS AN EMULSIFIER, THIS EMULSIFIER BEING PREPARED BY REACTING A FIRST COMPONENT COMPRISING A HYDROPHILIC POLYOL WITH A REPAIR OF ISOCYACANATE DEYALOYALITE HAIR COFFEE DEYOYALITE OR MORE WITH A SECOND COMPONENT INCLUDING A CETOXIME TO FORM A PREPOLYMER BLOCKED WITH OXIME, BY REACTING A THIRD COMPONENT INCLUDING A POLYFUNCTIONAL AMINE HAVING A FUNCTIONALITY OF TWO OR MORE WITH THE PREPOLYMER BLOCKED WITH OXIME A REACTION TO FORM 'AMINE, BY REACTING A FOURTH COMPONENT INCLUDING AN ACID WITH THE AMINE REACTION PRODUCT SO AS TO OBTAIN AN AMINE SALT OF INFINITELY DILUABLE POLYURETHANE PREPOLYMER IN WATER, AND THINNING THE AMINE SALT OF PREPOLYMER OF POLYURETHANE WITH WATER. THE INVENTION APPLIES IN PARTICULAR TO ADDITIVES FOR PAPER.

Description

The emulsion polymerization probably originated in

  observations by early scientists of latex or natural sap exuded by many plants. Without a doubt, the most important of them is the natural rubber latex. Natural rubber is a colloidal dispersion resembling milk, in water, of polyisoprene particles protected from

  coagulation by natural proteins and emulsifiers.

  The first reference to emulsion polymerization is

  given in German Patent No. 250690 of 1909.

  Work on emulsion polymerization continued in Germany during the First World War with relatively little progress in technical development. Industrial development of polymerization

  1_5 in emulsion seems to have started in the late 1920s.

  In German Patent No. 558890 (1927), the polymerization of butadiene is described in a synthetic latex using soaps as emulsifiers and peroxide.

of hydrogen as initiator.

  The first major breakthrough in the development

  The industrialization of the emulsion polymerization occurred in 1938 when it was shown that the polymerization occurred in the aqueous phase and not in the monomer droplets. Understanding the mechanism of emulsion polymerization has broadened the knowledge, thus, of predictions and improvements in techniques

could be done.

  The emulsion polymerization has the following advantages over other processes such as bulk polymerization or solution polymerization: (1) An emulsion polymerized product, such as the latex itself, is in an ideal form for use in paints, coatings, adhesives, coating and impregnation of paper, leather treatment, textile treatment, immersion and foam rubber

of latex.

  (2) The control of the initiator, the propaga-

  tion, chain transfer and terminal reaction.

  sound is easy and, in most cases, at a

  relatively low temperature of the polymerization.

  (3) The emulsion polymerization is suitable for

easy operation continuously.

  (4) High polymerization rates can be achieved at the same time as high degrees of polymerization. (5) Contrary to solutions of polymers,

  the viscosity of a latex is independent of the molecular weight

  re of the polymer it contains. Thus, we can get

  high concentration of polymer at a low viscosity.

  (6) Emulsion polymerization uses water as an inexpensive solvent, eliminating the problems of

  solvent recovery and fire risk factors.

  (7) When a solid product is required, the work of the polymer is not problematic because the latex is simply coagulated appropriately and the coagulated crumbs are washed with water or other solution.

aqueous, pressed and dried.

  It has been said that the choice of an emulsifier was probably the single most important factor for emulsion polymerization. First, the emulsifier must produce a stable emulsion between the monomer and water phases and subsequently a stable latex. Second, it must not interfere adversely with the system

  initiation or propagation of the reaction.

  Thirdly, since emulsifying residues will remain in the recovered product after polymerization, it must not

  not imparting harmful properties to the product.

  Many synthetic emulsifiers have been studied for their effectiveness in emulsion polymerization. Depending on the nature of the hydrophilic groups, the surfactants can be divided into four classes: (a) anionic, (b) cationic, (c) amphoteric and (d) nonionic. Each of these main groups can

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  be chemically subdivided according to the hydrophilic group (ie carboxylic acids, sulphates, sulphonates) and the hydrophobic group (such as alkyl, alkylaryl, alkylamide, alkyl ester). So the choice among the many possible permutations and combinations is

Very important.

  Suitable surfactants commonly used in emulsion polymerization processes according to the prior art include anionic surfactants such as potassium caprylate, potassium myristate, potassium palmitate, sodium stearate and the like. potassium, potassium oleate, sodium decyl sulphonate, sodium dodecyl sulphonate, sodium tetradecyl sulphonate, sodium decyl sulphate, sodium lauryl sulphate, dehydroabietate

  potassium, sodium rosinate, sulphate esters,

  alkyl sodium succinate and the like; surfactants

  cationic active agents such as long chain quaternary amine salts; and nonionic surfactants such as ethylene oxide condensates of oleyl alcohol, cetyl alcohol, lauryl alcohol, and the like, ethylene oxide condensates of the type described in US Pat. linoleic acid, lauric acid, ricinoleic acid, caproic acid and the like, a block copolymer of ethylene oxide and propylene oxide and condensates

  ethylene oxide of octyl phenol or nonyl phenol.

  The role of the emulsifier in the emulsion polymerization is threefold: (a) an increased amount of the monomer is taken into the water phase due to solubilization in the micelles; (b) the unsolubilized monomer is emulsified into fine and stable droplets; and (c) the latex particles created are protected against

  coagulation during and after the polymerization.

  It is known that different emulsifiers have molar concentrations below which micelle formation does not occur. It's the concentration

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  critical in micelles, that is to say cmc. In most cases, no significant polymerization occurs

  below the critical micelle concentration (cmc).

  As the concentration of emulsifier is lowered, the number of formed latex particles decreases. It is known that the residue of the emulsifier left in the system of

  latex may leave to it, properties not

  desirable, indeed the latex may lose some of

its stability.

  It has been recognized that an emulsifier must bring three basic properties to a latex system. These properties are as follows: (a) good solubility at the polymerization temperature, (b) good solubilization, and (c) impart good latex stability. Moreover, the emulsifier must not interfere with the initiation or propagation of the polymerization reactions. The variety of initiator systems in emulsion polymerization processes is not less than the variety of emulsifiers described. All systems used commercially are based on the release of a free active radical. These free active radicals are produced by one of two means: (a) decomposition

  of a compound in free radicals or (b)

  action of chemical agents to produce free radicals. The most commonly used initiators

  are the compounds containing a peroxide bond, that is,

  to say -0-0-. Organic peroxides can be considered as derived from hydrogen peroxide

  by replacing hydrogen with organic groups.

  Specific initiators for hydrogen peroxide include diisopropyl peroxycarbonate, caprylyl peroxide, lauroyl peroxide, benzoyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, peroxide, and the like. methyl ethyl ketone, di-tert-butyl peroxide, cumene peroxide and tert-butyl peroxybenzoate. Compounds that release peroxydisulfate ions can also be

used as initiators.

  Hydrogen peroxide-iron systems can be used as initiators for the polymerization of certain monomers, such as methyl methacrylate and acrylonitrile, while organic hydroperoxides are preferred for less polar monomers such as styrene and butadiene. For the manufacture of SBR (styrene-butadiene rubber) "cold", we meet

  most frequently formulas containing hydro-

  p-methane peroxide, pinon hydroperoxide or

  diisopropylbenzene hydroperoxide.

  In addition to emulsifiers and initiators, certain materials may be added to the emulsion polymerization reaction mixture to retard or inhibit the propagation reaction. Any substance trapping free radicals and either destroying them, preventing them from reaching the polymerization site or producing, by transfer, another free radical that is not active as a polymerization initiator or inhibitor, can be used. Some substances can act both to delay and inhibit. Some commonly used substances are diethylhydroxylamine, hydroquinone, hydroquinone methyl ether, p-aminophenol,

  soluble dithiocarbamates in water and others.

  The present invention relates to a method and networks thus produced where traditional surfactants and / or emulsifiers are replaced by an amine salt of polyurethane prepolymer. This amine salt of polyurethane prepolymer eliminates the effects of residues in the finished product, due to the emulsifier remaining therein, since the salt, during the curing of the latex, becomes a

part of the cured latex.

  The new amine salt of polyethylene prepolymer

  urethane, when used in emulsion polymerization systems, has been shown to act as a

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  As a particle initiator, it can replace the latex used to prepare latex compositions where a high degree of grain size uniformity is required (for example, see U.S. Patent No. 3,397,165). It has been found that the new polyurethane prepolymer amine salt, when used in an emulsion polymerization system, acts as

  a stabilizing medium for the latex system.

  In the process according to the invention, the initiation of the latex is accomplished according to known processes. The aqueous reaction medium is introduced into the reaction zone and the monomer (s) to be polymerized are then continuously fed to the aqueous medium in the reaction zone together with a catalyst and, if desired, surfactants, a buffer and others. The term "aqueous reaction medium" means water plus any other constituent, such as a catalyst, surfactants, buffer and the like, present

  in the reaction zone o is carried out the polymerization

  according to this method. The temperature of the initialization varies according to the type of the monomers used and the quantity and type of the catalyst used, and those who are competent in the matter will know the correct temperature for any given system. Typically, for the polymerization of acrylate monomers or lower alkyl methacrylates, such as methyl methacrylate, N-butyl acrylate and the like, it is preferable to initiate the polymerization at a temperature of the order

  from 40 to about 840C depending on the catalyst employed.

  Any reactor, well equipped, can be used for the implementation of the polymerization reactions in

  emulsion. The different types of reactors and their adaptation

  The properties of emulsion polymerization are well known to those skilled in the art. Typically, a stirred tank with a means for controlling temperature and pressure, a means for producing a continuous supply of monomer, catalyst, agent

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  surfactant, buffer and the like, a means for continuously withdrawing a portion of the contents of the reservoir and, if desired, means for producing an atmosphere

  inert (like N2) above the reagents, is advantageous

  used as a reactor. The emulsion polymerizable monomers which are useful in the process according to the invention are all monomers having at least one olefinic unsaturated group having the formula c = C which are known to those skilled in the art for addition polymerization. under conditions of emulsion polymerization in an aqueous medium. These monomers are so well known to those skilled in the art that they do not require further elaboration here. However, there may be mentioned unsaturated compounds such as ethylene, propylene, 1-butane, 2-butene, isobutylene, 1-pentene, 2-methyl-2-butene, 1-hexene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene, 2,4,4-trimethyl-1-pentene, 6-ethyl-1-hexene, 1-heptene, 1-octene , 1-decene, 1-dodecene, allene, butadiene, isoprene, chloroprene, 1,5-hexadiene, 1,3,5hexatriene, divinylacetylene, cyclopentadiene, dicyclopentadiene, norbornene , norbornadiene, methylnorbornene,

  cyclohexene, styrene, alpha-chlorostyrene, alpham-

  thylstyrene, allylbenzene, phenylacetylene,

  1-phenyl-1,3-butadiene, vinyl naphthalene, 4-methyl

  styrene, 2,4-dimethylstyrene, 3-ethylstyrene,

  2,4-diethylstyrene, 2-methoxystyrene, 4-methoxy-3-

  methylstyrene, 4-chlorostyrene, 3,4-dimethyl-alpha-

  methylstyrene, 3-bromo-4-methyl-alpha-methylstyrene, 2,5dichlorostyrene, 4-fluorostyrene, 3-iodostyrene, 4cyanostyrene 4-vinylbenzoic acid, 4-acetoxystyrene, 4-vinyl benzyl alcohol , 3-hydroxystyrene, 2474511 i

  1,4-dihydroxystyrene, 3-hydroxystyrene-1,4-dihydroxy-

  styrene, 3-nitrostyrene, 2-aminostyrene, 4-N, N-

  dimethylaminostyrene, 4-phenylstyrene, 4-chloro-1-

  vinylnaphthalene, acrylic acid, methacrylic acid, acrolein, methacrolein, acrylonitrile, methacrylonitrile, acrylate, methacrylamide, methyl acrylate, methyl methacrylate, norbornenyl acrylate, norbornyl diacrylate, 2-hydroxyethyl acrylate, 2-phenoxyethyl acrylate, acrylate

  of trimethoxysilyloxypropyl, dicyclopentyl acrylate

  nyl, cyclohexyl acrylate, 2-tolyl acrylate and

  hexylethyl, N, N-dimethylacrylamide, isopropyl methacrylate, ethyl acrylate, methyl alpha-chloroacrylate, betadimethylaminoethyl methacrylate, N-methyl methacrylamide, ethyl methacrylate, acrylate of 2-ethylhexyl, neopentyl glycol diacrylate, cyclohexyl methacrylate, methacrylate

  beta-bromoethyl, benzyl methacrylate, methacrylate

  phenyl crylate, neopentyl methacrylate, butyl methacrylate, chloroacrylic acid, methyl chloroacrylic acid, hexyl acrylate, dodecyl acrylate, 3-methyl-1-butyl acrylate, 2-ethoxyethyl acrylate, phenyl acrylate, butoxyethoxyethyl acrylate, 2-methoxyethyl acrylate, acrylate d. isodecyl, pentaerythritol triacrylate, methoxy poly (ethyleneoxy) acrylate, tridecoxy poly (ethyleneoxy) acrylate, chloroacrylonitrile, dichloroisopropyl acrylate, ethacrylonitrile, N-phenyl

  acrylamide, N, N-diethylacrylamide, N-cyclohexyl-

  acrylamide, vinyl chloride, vinyl chloride

  deene, vinylidene cyanide, vinyl fluoride, vinylidene fluoride, trichloroethene, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl butyral, vinyl propionate, vinyl chloroacrylate, isopro acetate, pentyl, vinyl formate, vinyl methoxyacetate, vinyl caproate, vinyl oleate, vinyl adipate, methyl vinyl ketone, methyl isopropenyl

  ketone, vinyl phenyl ketone, methyl alpha-chlorovinyl-

  ketone, ethyl vinyl ketone, divinyl ketone, allylidene diacteate, methyl vinyl ether, 2-methoxy ethyl vinyl ether, 2 chloroethyl vinyl ether, methoxyethoxy ethyl vinyl ether, hydroxyethyl vinyl ether, 1 aminoethyl vinyl ether, alphamethylvinyl methyl ether, divinyl ether, divinyl ether,

  ethylene glycol or diethylene glycol or triethanol-

  amine, cyclohexyl vinyl ether, benzyl vinyl ether, phenethyl vinyl ether, cresyl vinyl ether, hydroxy phenyl vinyl ether, chlorophenyl vinyl ether, naphthyl vinyl ether, dimethyl maleate, diethyl maleate, maleate of di (2-ethylhexyl) maleic anhydride, dimethyl fumarate, dipropyl fumarate, diammonium fumarate, vinyl ethyl sulfide, divinyl sulfide, vinyl-p-tolyl sulfide, divinyl sulfone vinyl ethyl sulfone, vinyl ethyl sulfoxide, vinyl sulfonic acid, vinyl sodium sulfonate, vinyl sulfonamide, vinyl benzamide, vinyl pyridine, N-vinyl pyrrolidone, N-vinyl carbazole, N (vinyl benzyl) -pyrrolidone, N (vinyl-benzyl) piperidine, 1-vinyl pyrene, 2-isopropenyl furane, 2-vinyl dibenzofuran, 2-methyl-5-vinyl-pyridine, 3-isopropenylpyridine , the

  vinylpiperidine, 2-vinyl-quinoline, 2-vinyl-

  benzoxazole, 4-methyl-5-vinyl-thiazole, vinyl thio-

  phene, 2-isopropenyl thiophene, indene, coumarone,

  1-chloroethyl vinyl sulfide, vinyl-2-ethoxyethyl-

  sulphide, vinyl phenyl sulphide, vinyl-2-naphthyl-

  sulfide, allyl mercaptans, divinyl sulfoxide, vinyl phenyl sulfoxide, vinyl chlorophenyl sulfoxide, methyl vinyl sulfonate, vinyl sulfoanilide, and the like.

  Catalysts, buffers and other constituents

  In the method according to the invention, it is possible to use the same emulsion polymerization mixture as those which can be employed in the known processes according to the prior art emulsion polymerization. The particular choice of materials, other than emulsifier, to use is not the invention and is a routine matter

  in the technique of emulsion polymerization.

  The catalyst employed is typically a free radical initiator or a redox catalyst. As an illustration of suitable catalysts we can mention that we can use

  initiators of free radicals such as hydrogen peroxide

  gene, peracetic acid, t-butyl hydroperoxide,

  di-t-butyl peroxide, dibenzoyl peroxide, hydro-

  Benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, 2,5-dimethyl-2,5-bis (hydroproxy) hexane, the acid

  perbenzoic acid, t-butyl peroxy-pivalate,

  t-butyl acetate, azobis-isobutyronitrile, ammonium persulfate, sodium persulfate, potassium persulfate, sodium perphosphate, potassium perphosphate, isopropyl p-hydroxycarbonate) and the like. redox catalyst systems such as sodium persulfatesodium formaldehyde sulfoxylate, hydroperoxide cumene-sodium metabisulfite,

  hydrogen peroxide-ascorbic acid, sulfur dioxide

ammonium persulfate and others.

  The catalysts are employed at the usual catalytically effective concentration known to those skilled in the art of emulsion polymerization.

  The new polyamine polymer amine salt

  urethane as an emulsifier is the subject of the application for

  U.S. Patent No. 034,375 filed April 30, 1979.

  The polyurethane polymer amine salt is

  essentially consists of the reaction product of a pre-

  NCO-terminated polymer blocked with an oxime in reaction with an amine and further reacting with an acid to thereby obtain amine salts of

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  floating polyurethane and infinitely dilutable in water.

  Throughout this description, the term

  "Float" will indicate the condition or condition of the amine salts of the amine reaction product with the oxime-blocked isocyanate prepolymers in an aqueous medium. It is not always apparent if the polyurethane polymers in water are a microscopically heterogeneous mixture

  two or more finely divided phases, that is,

  say liquid in liquid, and thus a dispersion or if the polyurethane polymers are partially or totally dissolved in the aqueous phase and thus a solution. The polyurethane polymers have been observed in water where the resulting product appears to be optically clear or limpid, indicating a homogeneous solution. In this situation, it is thought that the individual molecules

  polyurethane polymers are not bonded together.

  On the other hand, polyurethane polymers have also been observed in water where the resulting product is cloudy, indicating dispersion. So, in this

  description, the term floating will mean the new

  amine salts in an aqueous system and can be either a

  homogeneous solution, dispersion or any combination.

  In order to obtain a satisfactory end product having suitable film-forming characteristics, it has been recognized that branched reactants should be incorporated in the preparation of the floating polyurethane in order to obtain the crosslinking necessary to produce a three-dimensional polymeric structure upon curing. Therefore, we will understand, in any

  the following description, which is the polyol, the amine

  polyfunctional, the prepolymer, part of each

  or any combination of them shall have a function

  reactive quality greater than two.

  The new polyurethane polymer amine salt is formed in four basic steps. First, a polyol is reacted with a polyisocyanate to prepare a prepolymer

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  finished by NCO. The prepolymer is blocked with an oxime in the second step. Third, the NCO-terminated and oxime-blocked prepolymer is reacted with one or more selected polyfunctional amines as will be described hereinafter. The reaction product of amine is reacted with an acid. It has been found that in order to obtain a product having useful properties it is necessary to use a reagent having a functionality

  greater than 2 in the first and / or third steps.

  Thus, the functionality of the NCO terminated prepolymer plus the functionality of the polyfunctional amine will be

at least 4 or more.

  It has been found that the reaction product of the polyfunctional amines with the oxime-blocked NCO-terminated prepolymer has a tendency to increase in viscosity with time until gelling occurs.

  Thus, according to another aspect of the invention,

  It has been unexpectedly found that the gel time and the viscosity of the dispersion of the floating polyurethane polymer can be controlled and / or adjusted by adding a secondary amine to the reaction product. The isocyanate-capped polyoxyalkylene polyol prepolymer determined by NCO or the urethane prepolymer useful in the invention are prepared by reacting polyoxyalkylene polyol with an excess of polyisocyanate, for example toluene diisocyanate. The polyol must have a molecular weight of about 200 to about

  200,000 and preferably of the order of 600 to about 6,000.

  The hydroxyl functionality following the reaction is from 2 to about 8. When the isocyanate functionality of the polyol and the corresponding functionality of the isocyanate of the prepolymer is 2, the functionality of the amine reactant of step 3 must be greater than 2. When the isocyanate functionality of the prepolymer is greater than 2, the functionality of the reactive amine in step 3

can only reach 2.

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  The preferred NCO or isocyanate capped prepolymer consists of a mixture of: (1) an isocyanate capped hydrophilic polyoxyethylene diol, this diol having an ethylene oxide content of at least 40 mol%; and (2) an isocyanate capped polyol having a hydroxy functionality of between 3 and 8 before being capped; this isocyanate-capped polyol being present in an amount of between 2.9 and 50% by weight of (1)

and (2).

  The polyoxyethylene diol is the reaction product of alkylene oxides of which at least 40 mol% are composed of ethylene oxide with an initiator such as ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol or mixtures thereof. Preferably, the molecular weight of the diol is between about

400 and about 6,000.

  Examples of suitable polyols are

  Preferred (polyisocyanate-capped): (A) substantially linear polyols formed, for example, by reaction of ethylene oxide with ethylene glycol as the initiator. Mixtures of ethylene oxide with another alkylene oxide may be employed as long as the

  molar percentage of ethylene oxide is at least 40%.

  If the linear polyethers are mixtures of ethylene oxide with, for example, propylene oxide, the polymer may be either a random or block copolymer. A second class of polyols (B) contains those having a hydroxyl functionality of 3 or more. These polyols are commonly formed by the reaction of alkylene oxides

  with a polyfunctional initiator such as trimethylol

  propane, pentaerythritol, and others. To form the polyol B, the alkylene oxide used may be ethylene oxide or mixtures of ethylene oxide with other alkylene oxides as described above. Useful polyols may further be represented by (C) branched or linear polyfunctional polyols

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  represented in A and B above with an initiator or

  crosslinking agent. We can cite as a specific example

  C, a mixture of polyethylene glycol (weight

  molecular weight of the order of 1,000) with trimethylol-

  propane, trimethylolethane or glycerol. We can

  subsequently react this mixture with polyiso-

  cyanate in excess to obtain a prepolymer useful in the invention. Alternatively, the linear or branched polyols (such as polyethylene glycol) can be reacted

  separately with an excess polyisocyanate. We can also

  The initiator, such as trimethylolpropane, should be separately reacted with the polyisocyanate. Subsequently, both capped materials can be combined to

form the prepolymer.

  The polyoxyalkylene polyol is terminated or capped by reaction with a polyisocyanate. The reaction can be carried out in an inert and moisture-free atmosphere, for example under a blanket of nitrogen, at atmospheric pressure and at a temperature of between 0 and about 120 ° C. for about 20 hours depending on the temperature and the degree of agitation. This reaction can also be carried out under atmospheric conditions provided the product is not exposed to excess moisture. Capping of the polyoxyalkylene polyol can be carried out using stoichiometric amounts of the reactants. However, advantageously, an excess is used

  isocyanate to ensure complete capping of the polyol.

  Thus, the ratio of isocyanate groups to hydroxyl groups used is between about 2 and about 4 isocyanates for 1 hydroxyl, and preferably between about 2 and about 2.5 isocyanates for 1 hydroxyl

in molar ratio.

  For maximum strength, solvent resistance, heat resistance, and the like, isocyanate capped polyoxyalkylene polyol reaction products are formulated to provide a network of 2474511.

crosslinked polymer.

  Any ketoxime is effective and among these, there may be mentioned acetone oxime, butanone oxime, cyclohexanone oxime and the like. It is believed that an oxime based on a relatively volatile ketone is preferable. The most preferred oxime is butanone oxime,

  also known as methyl ethyl ketoxime.

  Oxime mixtures can be used, but there is no known merit to doing so. The proportions of the oxime used can be between about 0.7 and

  about 1.2 equivalents of the isocyanate groups present.

  1.05 to 1.15 equivalents are preferred.

  To prepare the blocked prepolymer, the oxime and prepolymer are simply mixed at temperatures between 50 and 70 ° C for about one-half to one-and-a-half hours. Solvent is not generally necessary although materials such as butyl cellosolve acetate may be employed. Other suitable solvents include materials that are neither reactive with the oxime group nor with the urethane group. Based on the moles of the oxime and NCO reactive groups involved, the NOH / NCO molar ratio should range from about 0.7 to about 1.2 and preferably from about 1.05 to about 1.15. Generally, it is very effective to use enough oxime for a reaction

complete with NCO groups.

  To prepare the blocked prepolymer, the oxime is selected to give a product undergoing curing reactions in a reasonable time at a reasonable temperature. The curing temperature is influenced by materials such as substrates and catalysts, so to cure the floating polyurethane dispersion temperatures outside the range of 140 to 180 ° C can be employed. Curing temperatures of at least 120 ° C. C have been adapted considering the curing times to be employed. Lower temperatures result in longer dwell times

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  curing unless a catalyst is employed. Many oximes and catalysts that can be employed are described in: Petersen, Liebigs Ann. Chem., 562 (1949) page 215; Wicks, Progress in Organic Coatings, a (1975), pp. 73-99; and Hill et al., Journal of Paint Tech. , 43 (1971) page 55. The oximes having the above release temperatures are liquid materials at temperatures of the order of 80 C, and the condensation products with urethane prepolymers are miscible with water. or may be dispersed in water using surfactants. In general, oximes are straight or branched, cyclic aliphatic materials containing from 2 to 8 (preferably from 3 to 6)

carbon atoms.

  The oxime-blocked NCO-terminated prepolymer is reacted with an amine capable of forcing the polymer to cure at a low temperature. Many amines that can be used in the context of the present invention are well known and are known as polyfunctional amines. Specific examples of amines, without limitation, are ethylenediamine and 1,3-propane diamine.

  diethylenetriamine, triethylenetetramine, iminobis-

  propylamine, tetraethylenepentamine, methyliminobis-

  propylamine, 2 (2-aminoethylamine) ethanol and the polyoxypropyl amines manufactured by Jefferson Chemical Company, Inc., and sold under the trade names JEFFAMINE D-400, D-2000 and T-403. The polyoxypropylene amines are primary amines di- and trifunctional polyethersaliphatics derived from oxide adducts

of propylene of diols and triols.

  As can be observed by the indicated amines, some of them may be represented by the general formulas NH 2 R'-NH 2 'and HO-R'N 2 or R' is a

group of 2 to 6 carbon atoms.

  It has been found in our experimental work that the polyfunctional amines having a functionality of at least two primary amine end groups are the preferred amines to achieve proper cure.

  polyurethane polymer subsequently produced.

  Some of the polyfunctional amines may be represented by the formula H 2 (C n H 2 n-) z-C n H 2 n -NH 2 R 2 O is an integer from 1 to 4, n is an integer greater than 1 and R is hydrogen, an alkyl group of I at 4 carbon atoms, or a hydroxyalkyl group

from 1 to 4 carbon atoms.

  The polyoxypropyleneamines may be represented by the formula NH2CH (CH3) CHr0a "(CH) n2-NH2 ox is greater than 2 and by the formula CH2 {OCH2-CH (CH3tN2CH3CH2-C-CH2 - [OCH2-CH- The molecular weight of these polyoxypropyleneamines is between about and about 2,000 or more, with the preferred polyoxypropyleneamines having molecular weights of about 5 to 10% by weight. around 400

to 2,000. -

  The amount of polyfunctional amine added to the NC0-terminated and oxime-terminated prepolymer should be 0.6 to 1.5 equivalents, preferably

  between 0.9 and 1.1 equivalents based on the equi-

  total values of all isocyanate groups present in the NCO-terminated prepolymer. If the isocyanate functionality of the NC0-terminated prepolymer is 2,

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  a polyfunctional amine having a functional

  greater than 2 in order to obtain a satifying crosslinked product. If the isocyanate functionality of the NCO-terminated prepolymer is greater than 2, the functionality of the polyimine amine may be only 2. It will be understood that in the same reagent system the functionality of the NC0-terminated prepolymer and the The reaction between the oxime-blocked prepolymer and the polyfunctional amine is controlled by adding an acid or a mixture of an acid and water before the end of the reaction.

  the reaction. If one does not control the reaction of the pre-

  polymer blocked with oxime-amine at the right time, one can obtain an amine reaction product too viscous for the scope of the invention. Thus, the appropriate portions of the blocked prepolymer and the polyfunctional amine are placed in a reaction vessel and reacted under controlled conditions of heating and stirring. With experience, we have been able to determine the state

  of the reaction by observing the increase in viscosity.

  With good equipment such as temperature controlled mixing head devices, the reaction times can be controlled at high temperatures. For example, reaction times can be as low as 3 minutes

  at about 95 C, 4 minutes at about 80 C and so on.

  Preferred reaction times range from about one-half hour to about one hour with temperatures between about 40 and 60 ° C.. Acid or acid-water mixture is stirred sufficiently into the amine reaction product to lower the value of the reaction. pH

about 5 or less.

  The cationically stabilized floating polyurethane polymers are prepared by dispersing the amine reaction product in water in the presence of sufficient acid to obtain a pH of about 5 or less. In preparing the floating polymers, the acid can be added directly to the amine reaction product and mixed therein by further diluting with water. This is the preferred method. However, it is also possible to first add the acid to the water and then disperse the reaction product of amine in water. Other additives such as surfactants, ultraviolet absorbers, stabilizers, pigments, and the like can be formulated into

  floating polyurethane according to what is required.

  It was found that the pH was not controlled within the broad range indicated above, there were problems with settling or deposition and / or parts of the reaction product of amine reacted with water to form a crust. While the average range of pH value has to be considered, it has been found that one can use from 1 to 10 parts or more of

  the acid per 100 parts of the amine reaction product.

  The preferred range is between about 4 and 8 parts

  of acid per 100 parts of the amine reaction product.

  These floating polymers have been found to be stable for periods of several months at ambient temperatures, such as C, and also exhibit excellent

  resistance to freeze-thaw cycles.

  While any organic or inorganic acid will form the amine salt and will perform the function of controlling the pH value, the acids that have been used include glacial acetic acid, acrylic acid, citric acid, and the like. ethylenediaminetetraacetic acid, formic acid, glycine (aminoacetic acid),

  hydrochloric acid, lactic acid (alpha-

  hydroxypropionic acid), orthophosphoric acid (H3PO4), phosphorous acid (H3PO3), sulphamic acid, sulfuric acid, tartaric acid (dihydroxysuccinic acid),

  paratoluenesulfonic acid and mixtures thereof.

  The following specific examples will illustrate the present invention without in any way limiting its scope, and it will be understood that similar improved results can be obtained with other combinations of

  different compositions specified above.

  Preparation of the polyurethane prepolymer amine salt A preferred isocyanate-terminated polyol prepolymer is prepared by mixing a hydrophilic polyoxyethylene diol having an ethylene oxide content of at least 10 mole% with a polyol having hydroxyl functionality included between 3 and 8, this polyol being present in the mixture in an amount of the order of 10 to 20% by weight, by reacting with the mixture at a temperature between 0 and 120 ° C, an amount of a diisocyanate equal to 1 8-1.9 NCO equivalents relative to OH for a time sufficient to cap substantially all the hydroxyl groups of the mixture, adding additional diisocyanate to obtain 0.1-0.3 equivalents of NCO per initial equivalent of excess OH the theoretical amount necessary to react with the hydroxyl groups. To 100 g of the NCO-terminated polyol prepolymer at 24 ° C. in a stainless steel vessel, 22 g of butanone oxime are added with stirring. The reaction of

  the oxime with isocyanate is exothermic and the temperature

  The temperature changes to 60 C. A hot water bath is used to

  check the temperature between 80-90 ° C for 20 minutes.

  - After 20 minutes and with a temperature

at 90 ° C., 12 g of diethylene-

  triamine. The reaction with the amine is also exo-

  thermal, which speeds up the chain extension.

  The viscosity continues to increase and after 90-95 ° C., 7.1 g of glacial acetic acid and 7.1 g of dissolved ophosphoric acid are slowly added.

  in 100 g of deionized water to control the viscosity.

  When all the acid / water mixture is introduced, the material is cooled and packaged. Water may be added to obtain the desired percentage of non-volatile materials

  (% N.V.) and the desired viscosity.

  The typical physical properties of the prepared emulsifier are as follows:

% N.V. 52.0

  pH 4.5-6.9 Viscosity (Brookfield LVF) 600-1000 cps Appearance clear solution of straw color

EXAMPLE 1

  In a 2-liter resin kettle equipped with a condenser, a thermometer, a graduated addition funnel, an agitator and a nitrogen source, 327.5 g of water were introduced. demineralized, 2.0 g of isoascorbic acid and 687.5 g (196.6 g of non-volatile products) of 24% nonvolatile cationic polyurethane prepolymer amine salt. This mixture was stirred

  and heated to 40 C under nitrogen blanket.

  At 400 ° C., 240.0 g of methacrylate were added to the kettle while stirring.

  of methyl, 120.0 g of butyl acrylate, 40.0 g of acrylate,

  nitrile and 8.0 g of acrylic acid. To the material in the resin cauldron, 4 cc of 30% hydrogen peroxide was added. The heat of the reaction forced the temperature to go from 41 to 470C in 3 minutes. The remaining monomer mixture was introduced at a rate to maintain a temperature of 55-60 C in the resin kettle without auxiliary heating. Separate 30% H 2 O 2 doses were added at 2 cc levels during addition of the monomer mixture. The total monomer mixture addition time was 39 minutes. When the last monomer mixture was introduced, the temperature was

from 57 C.

  Eight minutes after addition of the final monomer mixture and at a temperature of 54.degree. C., 0.1 g of isoascorbic acid was added to reduce the free monomer.

  dissolved in 10 cc of demineralized water and 1.0 g of hydro-

Tertiary butyl peroxide.

  The 2 liter resin cauldron (after

2474511-.

  conditioning of the latex) had no accumulation of solid and only required rinsing with water. The resulting latex had 36.9% total solids, a pH of 4.3, a surface tension of 43.2 dynes / cm and a Brookfield LVF N 1 viscosity at 60 degrees of 53.4 centipoise.

EXAMPLE 2

REACTIF% WET

  Vinylidene chloride 67 640 Butyl acrylate 15.0 144 Glacial acetic acid 2 16 40% polyurethane prepolymer amine salt of 17 400 solids Ascorbic acid 0.2 2 Hydrogen peroxide 1.0 10 Demineralized water - 800 In a 2-liter resin kettle equipped with a thermometer, a stirrer and an addition funnel, 800 g of water, 400 g of 40% strength polyurethane prepolymer amine salt were introduced. solids and 2 g of ascorbic acid. This mixture was heated to 36 C

with nitrogen purge.

  200 cc of a mixture consisting of 640 g of vinylidene chloride, 144 g of butyl acrylate and 16 g of glacial acetic acid were added and then 2 cc of 20% hydrogen peroxide was added. The heat of reaction raised the temperature to 46 C. The remainder of the monomer was added in increments of 100 cc together with 1-2 cc portions of hydrogen peroxide to maintain a temperature range of 45-50 C. After To add the last monomer, a portion of 2 cc of hydrogen peroxide was added and the batch was allowed to cook to reach maximum conversion. The latex had the following properties: Total solids 39.0% Conversion 81.6% Surface tension 52.8 dynes / cm pH 4.0 ez çç Ol 6 spToa ua% u 8z 9l

Z Z Z

9 L 8

OZ [Z SZ

6'Z'7 61

  spTod ue% uqpTI. & UT Bp ean.zo-MD: 01,6 s8d enbTlao apTovy eITTTuol: xoY * I4 & nq apoutL.zoy oa &% u op opBLzouq% .H 8u OUR SPIRIT XM spTod ue% poa u Z u SPToaT us W ,: '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' uittaoy 9tLl.% u op op uiou,% g SMadMmX SVd onbTlou apToV olAnl.% ap% lautLoVy euqpTlLuT B op auLoJ gya enbTIliou epTov BuPTILTr e aup enozIqS eaqpTl, úT. ap 0a1nuorq 01O * I.zpuod eSriaueoanod ua sgnubpuT% uos s. As a result, it is necessary to use the same method as that of the method described in US Pat. UUTTstE9 ammoo ouBl 9eu liod Bp eaqi & lodpd ap auu'ap les el 1.'STITUTE uoTs1TImn uoTusTapm6lod eun lueSJinTlT snossep-To Zk q ú soldwaxe salt E L LSzLz

S ' "NA'

Or

IIIIIII I

247451 1, 3

EXAMPLES 9. 10:

  Styrene Butyl Acrylate Acrylic Acid PAS

EXAMPLE 11

PAS methyl methacrylate

EXAMPLE 12

  Methyl methacrylate Acrylonitrile Butyl acrylate Acrylic acid PAS by weight

92 1

33 28

16 14

2 2

16 11

Weight% by weight

12-1 12-2

42 37

21 18

7 6

  PAS: amine salt of polyurethane prepolymer.

  Of course, the invention is not limited to the embodiments described which have been given by way of example. In particular, it includes all the means constituting technical equivalents of the means described and their combinations if they are executed according to its spirit and implemented in the

  framework of protection as claimed.

2474511.

Claims (16)

CLAIMS V E N D I C A T I 0 N S   1.- Process for the production of latex by polymer   aqueous emulsion composition of one or more polymerizable monomers, characterized in that said polymerization is carried out in the presence of a polyurethane prepolymer amine salt as an emulsifier, said emulsifier being prepared by reacting a first component comprising a hydrophilic polyol capped with isocyanate having a reaction functionality of two or more with a second   component comprising a ketoxime to form a precursor   polymer blocked with oxime, by reacting a third component comprising a polyfunctional amine having a functionality of two or more with said oxime-blocked prepolymer to form an amine reaction product, by reacting a fourth component comprising an acid with said amine reaction product, to thereby form an amine salt of polyurethane polymer infinitely dilutable in water and diluting said amine salt of   polyurethane polymer with water.   2. A process according to claim 1, characterized in that the above-mentioned polymerizable monomer is selected from the group consisting of lower alkyl acrylate, lower alkyl methacrylate, acrylonitrile, acrylic acid, vinylidene chloride, styrene and the like. mixtures.   3. A process according to claim 1, characterized in that the second component mentioned above is butanone oxime. 4. Process according to claim 3, characterized in that the third component mentioned above is chosen from   the group consisting of diethylenetriamine, triethylene-   tetramine, iminobispropylamine, tetraethylenepentamine, methyliminobispropylamine, 2 (2-aminoethylamine) ethanol, ethylenediamine, 1,3-propanediamine, polyoxypropyleneamine and their mixtures.   5. A process according to claim 4, characterized in that the fourth component mentioned above is chosen from the group of acids consisting of acetic, acrylic, citric, ethylenediaminetetraacetic, formic, lactic, o-phosphoric and phosphorous acids. -toluenesulphonic, sulfamic,   tartaric acid, hydrochloric acid, glycine and their mixtures.   6. A process according to claim 3, characterized in that the aforementioned third component is a mixture of diethylenetriamine and an amine selected from the group consisting of diethylamine, dibutylamine and dihexylamine. 7. A process according to claim 6, characterized in that the fourth aforementioned component is selected from aqueous acetic acid, aqueous o-phosphoric acid and their mixtures.   8. A process according to claim 4, characterized in that a viscosity controlling agent selected from the group consisting of diethylamine, dibutylamine and dihexylamine is incorporated into the third component supra.   9. A process according to claim 8, characterized in that the fourth component mentioned above is a mixture   aqueous glacial acetic acid and phosphoric acid.   10. An emulsion composition prepared by emulsion polymerization of a polymerizable vinyl monomer in the presence of an emulsifier, characterized in that said emulsifier is a floating composition consisting essentially of sequential reaction products of:   (a) a first component comprising a   isocyanate-capped hydrophilic polyether polyol polymer having a reactive functionality of at least two, said prepolymer consisting of a mixture of: (1) in the range of 2.9 to about 50% by weight of said blend of: an isocyanate-capped polyol having a hydroxyl functionality of between 3 and 8 before being capped; and (2) in the range of from 97.1 to about 50% by weight of said epoxy, and wherein said epoxide is in the range of from about 10 to about 10 weight percent. eb o u e egsT'l: 9.Ouzo   17iI UOT% .oTpueAaJ el uoles uo ':' TsodIoD - 'g 5.    u'.l: aXql: qTp.a auTmlI4.nqT 'u.'i: lp only one of the two adnoxl and onp elgOTqo euTMw eunsp e euarl. % utlt {.9T.p op Belpm a 9loTo9jd itesodcoo eaqTsTolo. ee ue ee ue ee,! Toe.zUo Ik1 uol% .oTPueaeJ v1 lol1es UOTTsodIOD -'1 0 eeuelguu s.nel% e euTolC2 ue 'enbçpXqzolqo' enblzra. 'enbpupln' enbTuolEns -eu! nlo: -dxne.ooqdsorqd 'enbTzoqldsotqd-o' enbT: loel 'enbpuzo, enbT1, ea: pBeu? e p epa! lZtq 'eabTil.To' enbTTLZOv 'lenbTIpoeO sepToa ueTsuoo sepToep ednozS el suop TsTo8qo Sz se 9pTopiJd jussodzoo emqTq.Uenb eo eeTipoUzo Zl UO uo oTpue. ael u oles UOTTsodUoD --I sueualfw sLznel 'I tiueuqlldod -xroZlod' euamTpeuqdoJd-'UUTUTOpOu! liqqfp '1 LOU - (had ulTltî1uTuu-8) 8' euTluIZ [do.zdsTqowu-aTlZtpu 'euiu.uedI oZ -eua. lZ49Pe, 'eulZoadsTuqou'ç' may have been a little! l9pZ BU UT.zeu.i! ILtRTP ue iuelseTuoo eadnoi el: swap sTeoqo 4se p.Top.d! .uesodwoo e! qTsTo.z el enb eo ue e! PsTzpoiso 1 uOTnl.WOrk UOT: Tsodwo03 -1i To OeTXo auouetanq el 51 ape 91.Topid muesoIdwoo puooes elb eo apsT.ipqose, o 1O uoTIoTp1aeae uoleu uoTTsodmoD ll q eoOTZ 4UeTTSTlnP unflp UoTlTsoOdWOo eun zeuzuo,; znod xnonbu epUu um uwuezIdmoo: luesodIoo easq! Telnb a (p) oaAe OUT ", p 01O aeuuoTI.oup.% Tnpoad TPeTaT JTe9. lUeSTe, B uae euTmI, p leu -uoToUp.z: .TnpoJd a TulT: ze.zoj ; u: u eluOTOUQoTOd elull a reueu.zdoo% tuesodwoo a5UTsToz a (o) osAe I BeUxos lq gnbolq e.zqwloTodgzd% 1TPeT, Tiu! pz% uesTBJ, ue 'ieTxo, l T pnbolq ezaq.lodgid a l: sTU jzazo; iznod emTxo% .o eun% ueuezldoo ,. ussodaoo puooes a (q) 91eo0e% 90Q suTom nsUp eu! lt.I.5g, p epixo ue Jneue.in l.uL 1OT P iPTel 'OeluteloosTp 9, lTOO selTqddoJpZtI TOTP euqlZn9iol & od unfp ueualpe 2474511 i   aqueous o-phosphoric acid and mixtures thereof   16. The composition of claim 13, characterized in that the aforementioned vinyl monomer is selected from the group consisting of lower alkyl acrylate, lower alkyl methacrylate, acrylonitrile, acrylic acid, vinylidene chloride, styrene and mixtures thereof. 17. A composition according to claim 12, characterized in that a viscosity controlling agent selected from the group consisting of diethylamine, dibutylamine and dihexylamine is incorporated in the composition. third component mentioned above.   18. A composition according to claim 17, characterized in that the fourth component mentioned above is an aqueous mixture of glacial acetic acid and phosphoric acid. An emulsion polymerization process for forming a homopolymer or copolymers of vinylidene chloride by heating a monomer charge containing vinylidene chloride in the presence of a water-soluble initiator and an emulsifier to a latex containing particles of said polymers, characterized in that an emulsifier comprising a composition consisting essentially of a floating polyurethane prepolymer amine salt wherein said salt is formed by reacting from about 0.7 to about 1 , 2 equivalents, based on the groups of NC0 of the prepolymer, of a ketoxime with a polyurethane prepolymer having free NC0 groups to form an oxime-blocked prepolymer, said prepolymer consisting of a mixture of the from about 2.9 to about 50 weight percent of said mixture of an isocyanate capped polyol having a hydroxyl functionality of from about 3 to about 8 before being capped; and in the range of from about 97.1% to about 50% by weight of said mixture of isocyanate-capped hydrophilic polyoxyethylene diol, said diol having an ethylene oxide content of at least% by mole, by reacting said prepolymer blocked with from about 0.6 to about 1.5 equivalents, based on the NC0 groups of the prepolymer, of a polyfunctional amine to form an amine reaction product, by reacting said amine reaction product with from about 1 to about 10 parts of an acid per 100 parts of said amine reaction product to form an amine salt and diluting said amine salt with water to have less than 60% of materials total non-volatile.   20. A process according to claim 19, characterized in that the aforesaid ketoxime is butanone oxime, the aforementioned polyfunctional amine is diethylenetriamine and the aforementioned acid is acid glacial acetic.   21. A process according to claim 19, characterized in that the above-mentioned polyfunctional amine is an aliphatic polyoxypropyleneamine having a weight molecular weight of about 230.   22. The process as claimed in claim 19, characterized in that the abovementioned polyfunctional amine has the formula CH2 0CH2CHCH3 - NH2 3H2 - '"N H   ## STR2 ## wherein NH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CHCH 2 CHCH 2] NH 2 o x + y + z is of the order of 5.3, with a weight of molecular weight of about 400.   23.- Process according to claim 19, characterized in that the above-mentioned polyfunctional amine   is selected from the group consisting of diethylene   triamine, triethylenetetramyl, iminobispropylamine, tetraethylenepentamine, methyliminobispropylamine,   2 (2-aminoethylamine) -ethanol, ethylenediamine, 1,3-propane-   diamine, polyoxypropyleneamine and mixtures thereof.   24. The process as claimed in claim 19, characterized in that the abovementioned acid is chosen from the group of acids consisting of acetic, acrylic, citric, ethylenediaminetetraacetic, formic, lactic, o-phosphoric and phosphorous acids. toluenesulfonic, sulfamic,   tartaric acid, hydrochloric acid, glycine and their mixtures.   25. The process as claimed in claim 23, characterized in that the abovementioned polyfunctional amine is diethylenetriamnine mixed with an amine chosen from the group consisting of diethylamine, dibutylamine and dihexylamine.   26.- Process according to claim 25, characterized in that the aforementioned acid is selected from aqueous acetic acid, aqueous o-phosphoric acid and their mixtures.   27. An emulsifier characterized in that it consists of a floating polyurethane prepolymer amine salt obtained by: (1) blending a hydrophilic polyoxyethylene diol having an ethylene oxide content of at least 40% by weight; moles with a polyol having a hydroxyl functionality of the order of 3 to 8, said polyol being present in the mixture in an amount between 1.0 and 20% by weight, by reacting with the mixture at a temperature of 0 to 120 C, a quantity of diisocyanate equal to 1.8-1.9 NCO equivalents for a time sufficient to cap substantially all the hydroxyl groups of said mixture and then adding additional diisocyanate to obtain 0.1-0.3 equivalents of NCO by an initial equivalent of OH in addition to the theoretical amount required to react with the hydroxyl groups to form an NCO-terminated prepolymer; (2) reacting said NCO terminated prepolymer with from about 1.05 to about 1.15 equivalents of butanone oxime to form a butanone oxime blocked prepolymer; (3) reacting said butanone oxime-blocked prepolymer with from about 0.9 to about 1.1 equivalents of diethylenetriamine to form an amine reaction product; and (4) reacting said amine reaction product with water containing from about 4 to about 8 parts of a mixture of acetic acid and phosphoric acid per 100 parts of said reaction product   of amine so that said floating composition results   aunt contains from about 20 to about 60% by weight non-volatile products.