JPS6181414A - Polymerization and polymer composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Formed from water bathable monomers. d IJ mother, often to obtain a stable water-in-oil dispersion of the polymer <4 phase 1
Manufactured from the following process. It is known to dehydrate this water. A typical example of such a method is disclosed in EP126528.

No. 4,059,552 and No. 4,172,066, microbeads of crosslinked water-insoluble water-swellable polymers prepared by reverse phase polymerization from water-soluble monomers containing crosslinking agents are used to control aqueous media. It has been proposed to thicken. In CB 2,007,238, the thickening blend is formed from a water-soluble polymer and a water-swellable crosslinked polymer. Printing thickener disclosed in European Patent No. 4X 85300292.1
ting pastethickener) is made by reverse phase polymerization of partially neutralized ethylenic trihydric acid in the presence of a crosslinking agent. In the method, the ratio of acid groups to bases (saHgroup) during polymerization is so: 20 to 10:90.

It is also known to prepare polymers from mixtures of monomers in which one monomer contains R pendant hydrophobic groups containing at least one human 90 carbyl group with at least 8 carbon atoms. When the above-mentioned groups are carried in particular on an alkoxy chain, ζ
They tend to associate between I4 molecules. Other monomers used in making the polymers often include materials such as ethyl acrylate, which is insoluble in water. Such a 44 remer is, for example, GB 1,167.524. 1,273,552.
U, S, 4J38,381°4.268,641.
4,384ρ96. 4,463,151 and E.P.
13836 and 1(15)820. They are subjected to precipitation polymerization (GBl, 167
, 524) or by bath liquid polymerization (emulsifying the TRS-mer in water and polymerizing it to form the desired l-mer emulsion).

In the above-mentioned patent, in which it is proposed to combine water or aqueous omega-mode crystal compounds in a bath solution, examples using water-solvent mixtures are described in detail (for example, F, P6
3, 8). There are probably two reasons why it is preferable to polymerize as an oil-in-water emulsion or as a solution in an organic solvent.

First, monomers containing hydrophobic groups are expected to have extremely poor water miscibility compared to conventional monomers due to their hydrophobic nature, and are not expected to be viable using conventional methods of polymerizing aqueous monomer solutions. . Second, monomers containing hydrophobic groups are often made from high HLB surfactants and therefore destabilize the emulsion, which would otherwise be destabilized by a high HLB surfactant. It is expected that.

(hereinafter l'i-, auto) gP 1(15) At 820, at least 10% acidic monomers, 05-30% specified hydrophobic monomers.

It has been proposed to produce a polymer optionally comprising a termonomer and optionally a crosslinking agent.

It is said that acrylic acid, for example, can be used as the acidic monomer, but in the examples, methacrylic acid is used, and the termonomer is not selected from various substances including acrylamide. The polymer is an emulsion copolymer obtained by copolymerization in an aqueous or porous system.

Ontoku copolymer, precipitate #:1 polymer, solution copolymer,
Although it is said that the copolymer can be either a solid copolymer or a non-aqueous dispersion copolymer, the polymerization in both examples is carried out by an oil-in-water emulsion method commonly used for this type of general associative polymer. ing.

In US 4.423.199, the same inventors mention a polymerization process that can be used to produce polymers containing other types of hydrophobic monomers. The examples only describe oil-in-water emulsion polymerization methods for linear polymers.

In US 4.524,175 (published after the priority date of the present application) water-in-oil emulsions of acrylamide/l'' decyl methacrylate copolymers are prepared by a special reverse phase polymerization. In said method: The dode/l methacrylate is dissolved in an oil phase rather than an aqueous phase, and an oil-soluble initiator is used in place of the conventional water-soluble initiator.

Although reverse phase polymerization to produce associative polymers containing hydrophobic groups has been described in the literature, it is actually described in US 4,5
The method described in 24.175 K is the only viable method in which the hydrophobic monomer is in the oil phase instead of in the aqueous phase as in true reverse phase polymerization.

Reverse phase polymerization is recognized as a polymerization process that provides polymers with properties that are particularly useful for many purposes, such as thickeners. However, it was previously thought that this method could not be applied to the polymerization of associative polymers containing hydrophobic groups.

The polymers of the present invention are prepared by the co-combination of ethylenically unsaturated monomers containing pendant hydrophobic groups having at least 8 carbon atoms and (bl water-soluble ethylenically unsaturated comonomers), all of which are The monomers are soluble in water as a blend, the polymer is produced by reverse phase merging, and the particles are characterized in that they have a dry size of 4 μm or less.

The polymer production process of the present invention consists of copolymerizing monomers, such that all the monomers are soluble in water as a blend, and the dispersion i in the non-aqueous liquid is formed from an aqueous solution of all the monomer blends. The present invention is characterized in that when the blend is reverse phase polymerized and co-EC-coated in the presence of a water-soluble initiator, a stable dispersion of an aqueous polymer in a non-aqueous liquid is formed.

Part of the present invention is that it is possible to form an aqueous 1d solution of any monomer blend that can be stably dispersed in a non-aqueous liquid for reverse phase polymerization, even if one of the monomers imparts a hydrophobic group. It is based on Chiji who said that. The monomer is typically an ester or amide of an ethylenically unsaturated acid or a (meth)allyl ether with a hydroxy-terminated activator having an HLB of 8 or higher.

It is quite surprising that such monomers can be incorporated into the dispersed phase of a water-in-oil emulsion without destabilizing the dispersed material before offshore or in a trowel.

The amount of specific 1Ili aqueous monomer makes the dispersion unstable5
If the content is less than 041"fii, potash is less than 25%, for example, 2 to 10%. Appropriate results can be obtained with 3 to 7% by weight.

The monomer has hydrophilic groups such as non-blocking acids, salts.

Preferably, the bo monomer (ml) is an ethylenically unsaturated monomer containing the group -BnAmR, preferably containing no amine, amide or hydroyanyl groups, where A is fort
? Ki'/ (CHt
CH.0), n is zero or preferably a positive 2 number usually greater than 5, sometimes greater than 10, preferably the polyoxyethylene chain may be interrupted by an ochinepropylene group. By suitably choosing the value of n1m and the radicals R, the solubility of the monomers and the properties of the final polymer can be controlled.

R is a hydrophobic group containing at least 8 carbon atoms.

At least a portion of the alkylene group may be propylene or a higher polyoxyalkylene group, but preferably the alkylene group is a carbyl group.

The hydrocarbyl group is usually 8 to 30. Preferably 10-2
4, most preferably Y'i contains 12 to 18 carbon atoms.

Alkyl examples are octyl, lauryl or stearyl, alkaaryl examples are ethylbenzene (-CzHaP
h), aryl such as naphthyl, aralkyl such as alkylphenyl O, where the alkyl group usually contains 6 to 12 carbon atoms, cycloalkyl (including polycyclic alkyl groups), or a mixture of the groups MI. Any of these groups may be substituted, provided that the preferred hydrosubstituents do not render the undant group hydrophilic.

The monomer can be a (meth)acrylic monomer or a (meth)allyl monomer. The bond between the ethylenically unsaturated carbon atom of the monomer and the group -BnAmR is usually a chain with at least 2, often at least 4 atoms, often containing one or more amides 9 in the steel.
．． Contains amine, ester or ether groups. The monomers may be -) or polyfunctional, exemplified by itaconic acid derivatives. In this case, both acid groups may be substituted with -BnAmR, or one may be unsubstituted or substituted with another esterification group, such as a methyl group or a higher alkyl group, such as butyl.

Preferred monomers are (meth)allyl ethers and amides or esters of ethylenically unsaturated carboxylic acids, preferably acrylamide, acrylic acid, methacrylic acid, maleic acid or itaconic acid. In the case of esters, the group may be directly bonded to the carboxyl group of the ethylenically unsaturated acid, or the esterified group (which may be bonded to
The esterifying group may contain an amine group or one or more ether or ester linkages. For example, groups R1, ff, quaternized groups in the amino groups of, for example, aminoalthyl esterification groups (quaternis
- rng group). Amide°
In the case of , the group -13nAmR may be bonded to an amide, )t7JU elementary atom, or may be bonded to a nitrogen atom of an aminoalkyl group bonded to an amide nitrogen such as a quaternized group.

Monomer (13) Monomer (a) is an allyl chloride or an alcohol, or a suitable ethylenically unsaturated 1
Preferred are compounds formed by reacting a surfactant, a nitrile, a halide, or an ester with a surfactant, preferably a human C3'I oxy-terminated surfactant having an HLB of 8 or higher.

Preferred monomers (a) are compounds having the formula R'CH=C(R'')QBnAmR.

In the above formula, R=C8-C50 alkyl or aralkyl.

When R" = H" = Q B n AmR or R'
=C0OR' and Q\CH2O, Mari Ii R
1=H.

R”=H or CH, or R” = CH2COORj and Q\CH2O.

R” = CH2QBnAmR and Q%CH2O.

COO or C0NR' (wherein R' = H or CH3), or C0OR'NCR'), and x-=anion such as C1-, Br- or CH5S
Oa- or n, when m=Q, Q = C0N
R'(R')-N(R")2X-(wherein, R
', R', R'o and X'''' are as above);
')Coo (in the formula, R5 is as described above); or Coo(R')OOC-(R')N"(Rj)2-X-
Or C00(R')COO-(R')N (R”
h.X-C in the formula R, R', R' and X- are as defined above) A suitable example of RX that can be used for quaternization is stearyl chloride 9.

A polymer with stability at the same time is used. Recent developments in associative rH reamers containing hydrophobic groups have all used acrylic monomers, including GB 1,167.524 and 1.27.
It is quite surprising that the allyl polymers proposed in No. 3,552 are so successful given that they are likely to be commercially unsuccessful due to the morphology in which they are produced.

Allyl ether can be prepared, for example, by reacting sodium or sodium alkoxide 9 with a suitable surfactant alcohol to form a sodium derivative, which is then reacted with allyl chloride 9 or optionally in the presence of a catalyst. It is produced by reacting alcohol with a surfactant.

Compounds in which Q contains C0OR'COO are produced, for example, by reacting acrylic acid with a hydroxycarboxylic acid and then esterifying with a surfactant alcohol or reacting with an ester. Compounds in which Q includes COOR'-000 are prepared by forming a half ester of a dicarboxylic acid and a surfactant alcohol and reacting this with an unsaturated diol and a diol.

All other monomers are described in the cited patents, or can be obtained by known methods.

In the present invention, it is particularly preferred that n is an integer of at least 5, preferably of at least 1O, and m is generally zero. This is because the IP lyoxyethylene chains promote iW dissolution in water or aqueous blends 9 of monomers. Preferably, the monomer is water-ormogenic. In this way, the comonomer or comonoa −
tQfbl must provide a water-soluble blend of monomer (13) with monomer (a),
(3) consisting of monomers, preferably highly waterizable monomers.However, a small amount of other R-rated monomers, such as ethyl acrylate, may be used, for example at most 5% or 10%. , the monomer may be self-combined into blend 9 from 41 + face to i4!
l is generally acrylic and may be nonionic, anionic or cationic. , noble anionic 7]7- is acrylic+i'l, methacrylic I'f2.
Contains acid groups such as 2-acrylamido-2-methylpronodisulfonic acid groups or other unsaturated sulfonic acids or carboxylic acids. Acids with good water solubility, such as acrylic acid, exist in the form of free acids, salts, or blends thereof, whereas acids with poor water solubility, such as methacrylic acid, exist in the form of salts, such as alkali metals, antamines, etc. Alternatively, it is preferable to exist in the form of an amine salt. Nonionic monomers that are often used in combination with anionic or cationic columnar polymers include acrylamide 9 or methacrylamide 9 . A suitable cationic columnar pick is:
Substituents are present such that the monomers are soluble in water, including dialkylaminoalkylacrylates or methacrylates and dialkylaminoalkylacrylamides 9 or methacrylamides 9. For example, dialkylaminoalkyl groups can exist in the form of soluble quaternary salts or other salts.

In general, 0 or more 1,1 water-bathable crosslinking additives may be included so that the polymer has the desired 1)' flexibility in an aqueous system. It may be uncrosslinked and dissolvable in an aqueous system.

The monomer is acrylic acid (as free j'i#I'2 or water-soluble salt) or acrylamide or its diluent. d remer is a particularly preferred polymer of the invention. Particularly preferred are polymers that have been crosslinked with a crosslinking agent such that the polymer particles are 11v wettable but not soluble in an aqueous system, such as a cold alkaline aqueous solution. For example, a particle has at least twice its shadow, sometimes at least 10 times its 8M.

These small M+li capable anionic particles are
It is particularly useful as a thickener for print R-st. The associative effect, which is believed to be curved in an associative polymer with the desired home and the hydrophobic groups, is usually made by reverse phase Togane e.g. 0.3-3 μm, generally about 1 μm.
It is extremely important that cross-linked particles with a size of .

The proportions of anionic, nonionic and cationic columnar polymers can vary over a wide range, in particular the proportion of any type of monomer present is typically 10 to 100% by weight relative to the total weight of monomer fbl. can exist in large amounts.

Reverse phase polymerization methods are generally carried out in the presence of l-remeric polymerization stabilizers.

Suitable suspension stabilizers include amphiphilic copolymers of hydrophobic and hydrophilic monomers that are soluble or dispersible in less polar liquids. Preferred stabilizers may be completely soluble or may form a 'fine dispersion in the continuous phase, but are not substantially soluble in the hexamer solution.

Typical examples of these are copolymers of alkyl acrylates or methacrylates with acrylic or methacrylic acid, and copolymers of alkyl acrylates or methacrylates with dialkylaminoalkyl (generally dimethylaminomethyl acrylate or methacrylate or quaternary ammonium salts of these amino monomers or Among these, the most suitable are copolymers of alkyl methacrylate (the alkyl group is a C+2-C+8 sulfuric acid hydrocarbon) and methacrylic acid or trimethyl-β- Copolymer 1 with methacryloxyethylammonium chloride and terpolymer of methyl methacrylate and hydroxyethyl acrylate. Suitable materials are B P 1,482,515
, US 4,339,371 and EP 126528.

The stabilizer is chosen depending on the particular copolymer being produced. The stabilizer for the polymer containing acrylic acid or its sodium salt is preferably cationic, and the stabilizer for the polymer containing dimethylaminomethyl acrylate or its salt or its quaternary ammonium derivative or other cationic polymers is preferably anionic.

The amount of suspension polymerization stabilizer used depends on the required polymer particle size. This is because at least monofl is required to be absorbed at the interface between the polymer particles and the continuous phase to stabilize the dispersion during polymerization and subsequent handling or use. Small particle size, e.g. 5 μm or less, typically 0.2 to 2 or 3 μm
0.05 to 10%, preferably 0.5 to 10%, based on the weight of the aqueous dispersion, when in the preferred size of the R radius of m
Amounts of stabilizer of 5% are common. If larger particles are sufficient, smaller amounts, e.g. 0. , ~0.5% stabilizer is sufficient.

The reverse phase polymerization method may be a reverse phase emulsion polymerization method.

In this case, it is carried out in the presence of a substantial amount of a low HLB water-in-oil emulsifier. However, reverse phase F product group +1
(legal is the preferred method. 9ε is the aqueous monomer l) The i quotient can be constructed simply by applying an IJJ shear force to the mixture Iζ of the aqueous monomer, oil, and stabilizer, but for a given It is sometimes a feed to add a small amount of a low HL B water-in-oil emulsifier to reduce the amount of shear force that must be applied to obtain particle size.
The emulsifier has an HLB of 7 or less, typically 4 mils. Typical emulsifiers include sorbitan monostearate, sorbitan monooleate, glyceryl monostearate and various ethoxylated fatty alcohols.

These usually dissolve in non-aqueous liquids. The low HLB emulsifier is preferably less than 1.5% by weight, and typically less than 0.1-0.3% by weight, based on the weight of the aqueous upper Zimmer dispersion in oil. .

The non-aqueous liquid is selected from the non-aqueous liquids normally used in reverse phase polymerization processes, such as the aromatic and aliphatic hydrocarbons and halogenated hydrocarbons described in EP 126 528 J. If desired, a polar liquid such as that disclosed in EP 126528 may be included.

Polymerization is induced using a hydroxyl initiator in a known manner. Even the use of oil-soluble initiators is unsatisfactory.

The resulting aqueous dispersion of monomer or polymer in oil generally contains 20-60% oil, 15-5% oil.
It contains 0% polymer or monomer and 15-50% water by weight.

The aqueous polymer dispersion may be dehydrated by known methods, usually by azeotropic distillation, preferably under reduced pressure. Dehydration is allowed for a sufficient time so that the final product is effectively anhydrous. Thus, the water content in the polymer particles is less than 25% by weight, generally the ambient moisture content of the particles when they are left in the atmosphere.
In other words, it will normally be less than 10%. The non-aqueous liquid in the initial aqueous dispersion is a blend of volatile and fixed oils, with the volatile oils being removed by azeotropic distillation. Furthermore, it may be replaced with a non-aqueous liquid.

A high HLB surfactant may be added to the final fraction to facilitate partitioning into water. Surfactants may be water soluble or oil bath compatible and generally have an HLB of 8 to 11.5.

Examples of the present invention will be described below.

Example 1 Direct esterification of itacon with 10 molar ethoxylate of stearyl alcohol in the presence of sulfuric acid,
produced a diester.

This ester and ammonium acrylate were mixed in reverse phase Sf
J was combined to form a copolymer. In particular, the aqueous phase contains 1
It was formed from 44 parts acrylic acid, 7 parts diester, 213 parts water, 81 parts 31.6% aqueous ammonia, and a fine thread of methylene bisacrylamide 9 and AZDN. 30% 5BP16) solution of a copolymer of methacrylic acid and 1 mole of methacrylic acid in a non-aqueous liquid, 117 parts of p13) monomer (a) e o 150 and 149 parts of 3BP1
It was formed from 1. Polymerization is carried out in the usual way,
Water and 38P11 were distilled off from the obtained inverse emulsion under reduced pressure to a final pressure of 10 mm/Hg and at a temperature of 95°C.

The resulting anhydrous dispersion was an effective thickener, for example during base printing.

Example 2 115.2 parts of acrylic acid, 28.8R(S acrylamide), 2.3 parts of 9 mole ethylene oxide condensate of 7-nylphenol acrylate (water-soluble derivative),
220 parts water, 65 parts 32% ammonia.

0.4 parts (7) Tetr13) Monomer (a) on D
, 0.04 parts of AZDN and 0.04 parts of methylenebisacrylamide were combined to form an aqueous phase. the non-aqueous liquid phase, 15 parts of 5pan 80;
42 parts of cetostearyl methacrylate: methacrylic d
(1:2 mol) 30%w/w% of copolymer 5B
P16) @Liquid, 117 parts of Pa1e Oil 150
and 149 parts of 5BPI 1. The aqueous phase was homogenized into the oil phase, deoxygenated, and treated with 0.043 parts of sodium metabisulfite and tertiary butylhydroxide).
The resulting inverse dispersion of hydrated polymer gel was dehydrated by distillation under reduced pressure to a final pressure of 10 mmHg and at a temperature of 95°C.

The resulting anhydrous dispersion was an effective thickener.

Example 3 181.8 parts of a 79.2% aqueous solution of acrylic acid, 0.4
Part Tetr13) Monomer (a) on B, 5
．． Allyl ether of 8 parts stearyl alcohol 10 moles ethoxylate.

118 parts water, 0.0424 parts AZDN and 116 parts
parts of 29.2% ammonia aqueous solution were mixed to form an aqueous solution. 7.4 parts of non-aqueous liquid phase 5pan 80
, 42.4 parts of inverse dispersion stabilizer (copolymer of 2 moles of motostearyl methacrylate and 1 mole of methacrylic acid)
30% 5BP16) solution.

127° 3 parts Pale Oil 60 and 1 part 5.7 parts 5EP16).

The aqueous phase was homogenized in the oil phase, deoxygenated, and tert-butylhuman 90 was added continuously as a 0.5% aqueous solution at a rate of 0.14 parts/min (to 2.058 parts of luoxide 9 and water). Polymerization was carried out using 0.042 parts of dehydrated sodium metabisulfite.The resulting inverse dispersion of the water-use polymer was distilled in the same manner as in Example 2 to form a dehydration-yielding polymer dispersion. Two parts of 5 molar ethoxylate of nonylphenol and 1 part of 4 molar ethoxylate of broad-cut lauryl alcohol were added per 100 parts of the decondensed aqueous dispersion.A 50% active co-d IJ mammary dispersion was thus formed and the water When dispersed with stirring, a highly viscous, dIJ mamer solution with 1 soap-gel rheological properties of associated water-soluble polymers was obtained. It was a useful flocculant.

Example 4 Acrylamide @ 85 mol and stearyl alcohol-1
A copolymer of 0 mole ethoxylate with 15 parts of allyl ether was prepared by inverse dispersion combination.

120.7 parts acrylamide, 0.83 parts Tetr
13) Monomer (a) on B, 269.6 parts water, 2
l) An aqueous solution containing over 1.3 parts of allyl ether, adjusted to 5 H, was added to 7.3 parts of
parts of Span 8 0, 4 1.4 parts of the stabilizer solution of Example 3, 108.9 parts of P13) Monomer (a) e
Homogenized in an oil phase containing 60 parts of Oil and 157.2 parts of ABPI l.

Deoxidize the 7-summer solution dispersion, and add 100 fl of the dehydrated polymer dispersion (SJ5 or nonylphenol).
105 parts of molar ethoxylate and 8 g of tertiary butylhuman 90 were polymerized using 4.1 parts of a 0.1% aqueous solution of Luoxite 9. The products were dispersed in water to form solutions with 0 soap-gel" rheological properties of associative polymer solutions. The polymer solutions were unaffected by mono- or polyvalent solutes. These polymer solutions were It has been found to be an effective flocculant for clay suspensions and a rheology modifier for printing yeast.

Example 5 The method of Example 3 was repeated, but with an additional 0.0
The resulting dehydrated polymer particles containing 63 parts of methylene bisacrylamide as the difunctional crosslinking comonomer were swollen in water to form a highly viscous but non-viscoelastic paste.

This yeast is useful as a vehicle for printing fabrics and other articles, especially those containing residual solutes, and retains print color when the paste is thickened with a conventional polyammonium acrylate microgel latex. (holoinf), participation (bl@adi)
ng) or shine (fluahlng) is imparted.

Claims (17)

[Claims] (1) (a) an ethylenically unsaturated monomer containing pendant hydrophobic groups having at least 8 carbon atoms;
b) Polymers produced by copolymerization with water-soluble ethylenically unsaturated monomers, in which all monomers are soluble in water as a blend, the polymer is produced by reverse-phase polymerization, and the particles are less than 4 μm. A polymer characterized by having a dry size. (2) a polymer in the form of particles with a dry size of less than 4 μm prepared by reverse phase polymerization of an aqueous solution of a monomer blend, wherein the monomers (a) contain pendant hydrophobic groups having at least 8 carbon atoms; A polymer consisting of an ethylenically unsaturated monomer and (b) a water-soluble ethylenically unsaturated monomer, characterized in that all monomers are soluble in water as a blend. (3) Ethylenically unsaturated carboxylic acids and sulfonic acids in the form of water-soluble free acids or water-soluble salts, acrylamides, methacrylamides, dialkyl acids in the form of water-soluble acid addition salts or quaternary ammonium salts; 3. A polymer according to claim 1 or 2, selected from aminoalkyl (meth)acrylates or (meth)acrylamides and water-soluble crosslinkers. (4) Polymers according to claim 1 or 2, wherein monomer (b) is selected from acrylic acid and acrylamide in the form of free acids or water-soluble salts. (5) A polymer according to claim 4 containing an amount of crosslinking agent such that the resulting particles swell but do not dissolve in an aqueous medium. (6) The monomer (a) is a (meth)allyl ether or an ester or amide of an ethylenically unsaturated acid containing a hydroxy-terminated surfactant having an HLB of 8 or more. Polymer according to any of the above. (7) Monomer (a) has the formula CH_2=CR'CH_2O
BnAmR (wherein R' is H or Me, A is propoxy or butoxy, B is ethoxy,
n is zero or an integer from 2 to 100, m is zero or an integer less than n, and R is a hydrophobic group having at least 8 carbon atoms.
Polymers described in Section. (8) Claims in which monomer (a) contains a polyethoxy chain between the ethylenically unsaturated carbon and the hydrophobic group, and the chain is of sufficient length to enable the monomer to dissolve in the aqueous phase. A polymer according to any one of ranges 1 to 7. (9) (a) an ethylenically unsaturated monomer containing pendant hydrophobic groups having at least 8 carbon atoms;
b) A process for producing a polymer by copolymerization with a water-soluble ethylenically unsaturated comonomer, wherein all the monomers are soluble in water as a blend and the dispersion in the non-aqueous liquid is a blend of all the monomers. A process for producing a polymer comprising copolymerizing the blend by reverse phase polymerization in the presence of a water-soluble initiator to form a stable dispersion of an aqueous polymer in a non-aqueous liquid. (10) Reverse phase polymerization is 3% by weight based on the non-aqueous phase
The method according to claim 9, which is a reverse phase suspension polymerization carried out in the presence of a low HLB surfactant: (11) The method according to claim 9 or 10, wherein the reverse phase polymerization is carried out in the presence of a suspension stabilizer which is an amphiphilic copolymer of a hydrophobic monomer and a hydrophilic monomer. (12) Claims 9 to 11, wherein monomer (a) is a (meth)allyl ether or ester or amide of an ethylenically unsaturated acid containing a hydroxy-terminated surfactant having an HLB of 8 or more. Any method described. (13) Monomer (a) has the formula CH_2=CR'CH_2
OBnAmR (wherein R' is H or Me, A is prooxy or butoxy, B is ethoxy, n is zero or an integer from 2 to 100, and m is zero or an integer less than n) , R is a hydrophobic group having at least 8 carbon atoms). (14) Claims in which monomer (a) comprises a polyethoxy chain between the ethylenically unsaturated carbon and the hydrophobic group, and the chain is of sufficient length to allow the monomer to dissolve in the aqueous phase. The method according to any one of the range items 9 to 13. (15) Monomer (b) is an ethylenically unsaturated carboxylic acid and sulfonic acid in the form of a water-bathable free acid or a water-soluble salt, an acrylamide, a methacrylamide, a dialkyl in the form of a water-bathable acid addition salt or a quaternary ammonium salt. 15. A method according to any of claims 9 to 14, wherein the method is selected from aminoalkyl (meth)acrylates or (meth)acrylamides and water-soluble crosslinkers. (16) A method according to claim 15, wherein monomer (b) is selected from acrylic acid and acrylamide in the form of free acid or water-soluble salt. (17) The method of claim 16, comprising an amount of crosslinking agent such that the resulting particles swell but do not dissolve in the aqueous system.