DE1669735C3 - Process for agglomerating aqueous dispersions of emulsion polymers with softening points above 20 degrees C. - Google Patents

Description

Agglomerating agent with decreasing polymerizate - unsaturated acids with glycols and polyglycols,

content of the dispersion. The agglomeration 20- to such as ethylene glycol, propylene glycol-1,2 and -1,3,

50 ^B / "strength dispersions is readily possible. With butylene glycol-1,2 and -1,4, diethylene glycol, tri-

a polymer content of less than 20 ethylene glycol and tetraethylene glycol, ethylene

weight percent, a decrease in the 5 unsaturated monomers with basic nitrogen atoms is often observed

agglomeration. _z . B. Vinylimidazole, vinylpyridine, 2-N-DimethylaTnino-

Particularly effective agglomerating agents, e.g. B. the ethyl acrylate, Mannich bases made of acrylamide or Dispersion of a copolymer of 95 parts of ethyl methacrylamide, formaldehyde and dialkylamines,

acrylate and 5 parts of acrylamide are effective even if their alkyl groups contain 1 to 12 carbon atoms,

Dispersions with very low polymer contents as well as their ammonium salts and ethylenically unsuitable

still agglomerating, but is generally saturated quaternary ammonium compounds, such as

Polymer contents below 10 percent by weight of the N-methylvinylpyridinium sulfate and N-methyl-N-Vi Effect only slight. Polymerisat- nylimidazoliniumchlorid, ethylenically unsaturated suI-

contents of the dispersion above 15, in particular fatty acid and its alkali, alkaline earth or ammo

between 20 and 50 percent by weight. 15 nium salts, e.g. B. vinyl sulfonic acid, styrene sulfonic acid

The pH of the dispersions is only of importance and the acrylic and methacrylic acid esters are of hydroxy importance when salt-forming agglomerating agents are alkyl sulfonic acids, eg. 3. Ethionic acid. turns werderi. Carboxyl group-containing agglomerates for copolymerization with such hydrophilic meriermittel are z. B. in the alkaline range, especially monomers (a) can be practically any ethylenically effective. Basic agglomerating agents, on the other hand, act as unsaturated monomers (b), which are particularly effective in the acidic pH range. Naturally forms water-insoluble homopolymers. Examples is a prerequisite for working at pH values of such monomers (b) are the esters and nitriles u lter 7 that the emulsifying agent, of the dispersions is also effective in unsaturated carboxylic acids, the acid having at least 3 to CA area. Examples of such men, such as the acrylic and methacrylic esters of given emulsifiers are lauryl sulfate, p-isooctylbenzene sulfate, if substituted alkanols and cycloalkanols, fonate, dodecylsulfonic acid and sulfuric acid half-z. B. of methanol, ethanol, n-propanol, isoesters of implementation products from p-isooctylphenol propanols of butanols, amyl alcohols and hexanols, with alkylene oxides such as ethylene oxide. of cyclohexanol, methylcyclohexanol, / 9-phenyl-

The polymer dispersions are ethanol, 2-cyanoethanol, 2-chloroethanol, cyclo-

drive 0.1 to 30, preferably 0.5 to 10 weight 30 dodecanols, cyclododecanols and stearyl alcohol,

parts on IOD parts by weight of solids of copolymer as well as acrylic and methacrylonitrile, vinyl aromatics,

sowed with hydrophilic groups in the form of aqueous such as styrene, A-methylstyrene, vinyltoluenes, ethylstyrenes

Added dispersions, the concentration of these and 2-chloro- and 2,4-dichlorostyrene and vinylnaph-

Dispersions varied within wide limits are thalin, vinyl esters, such as vinyl acetate, vinyl propionate, the

can. 35 vinyl esters of the so-called Versatic acids (e.g. the

The copolymers with the hydrophilic groups trimethyl acetic acid or the acid mixture, as one

are insoluble in alkali and contain 0.5 to 25% of it by reacting a mixture of diisobutylene

their weight of such ethylenically unsaturated and triisobutylene with carbon dioxide and water in

Monomer (a) polyn erisiert, which for itself polymerizwart receives acidic catalysts), vinyl ethers from

siert result in water-soluble homopolymers. Derar 40 alkanols with 1 to 12 carbon atoms, e.g. B. of methanol,

term monomers (a) are z. B. Ethylenically unsaturated ethanol, propanol, butanols or 2-ethyl

Mono- and dicarboxylic acids with at least SC atoms, hcxanols, vinyl halides such as vinyl chloride and vinyl

such as acrylic acid, methacrylic acid, crotonic acid, maleic chloride, and 1,3-dienes such as butadiene, isoprene,

acid, fumaric acid, itaconic acid, glutaconic acid, 3-mepiperylene and 2-chlorobutadiene.

thylglutaconic acid, muconic acid, dihydromuconic acid, 45 Preferred agglomerating agents are copoly-methylenemalonic acid, citraconic acid, mesaconic acid, merizates of acrylic and / or methacrylic acid of metha-methyleneglutaconic acid and their alkali, alkaline earth alcohol, ethanol, styrenic and isobutanol . and ammonium salts, and the half esters of butadiene, vinyl acetates, vinyl propionates and saturated dicarboxylic acids of the type mentioned and their maleic and fumaric esters of alkanols, salts of ethylenically unsaturated carboxamides, such as 50 with 1 to 4 carbon atoms, with acrylic acid, methacrylic acid, acrylamide, methacrylic acid , Maleic acid di- and mono-acrylamide, methacrylamide, N-methylolacrylamide amide, methylacrylamide and other N-alkyl carbon- and 'or N-methylol methacrylamide.
acid amides with 1 to 4 carbon atoms in the alkyl radicals, the optimal proportions of the monomers N-methylolcarboxamides, such as N-methylolacryl- (a) and (b) in the agglomerating agents are from case to amide and N-methylolmethacrylamide, the ethers of the- 55 case different. The agglomerating effect is more like N-methylolamide compounds, as far as it is stronger, the more polar the agglomerating agent is. Examples are drophilic, e.g. B. the methyl, ethyl, 3-oxabutyl, is the agglomerating effect of an aqueous 3,6-dioxaheptyl and 3,6,9-trioxadecyl ether dispersion of a copolymer of 95 weight and ethylene oxide adducts of such N-methylol percent Acrylicäthylcster and 5 percent by weight compounds, z. B. the N-methylolacrylamide, the 60 acrylic acid at pH 3 only slightly. It is strongly connected, e.g. B. the N-methylolacrylamide, which increases when the polarity of the hydrophilic N-methylol methacrylamide and the N-methylol carboxyl groups by converting into carboxymaleimids and ester amides of the maleic, lationcii with the addition of z. B. aqueous alkali fumaric and itaconic acid and the other above increases. A copolymer dispersion of 97 parts of said ethylenically unsaturated dicarboxylic acids, 65 ethyl acrylate and 3 parts of acrylic acid is very effective with and their salts, N-vinylamides, such as N-vinylacetamide, pH 9-10. In the case of emulsion copolymer and N-vinylpyrrolidone, ethylenically unsaturated poly- ses made from acrylic acid and styrene, basic hydroxyl compounds, e.g. B. Half esters from the ethylenic range a content of at least 5, better from 10 to

ie 69735

20 percent by weight of acrylic acid required because styrene is less polar than ethyl acrylate.

The agglomerating agents can be prepared by the customary emulsion polymerization processes be. In a special embodiment, agglomerating agents are used in their production first some of the monomers (b) polymerized and a mixture of the Monomers (a) and (b) is polymerized. Such Agglomerating agents are highly effective, even if only small amounts of monomers (a) are polymerized into them contain.

In a further embodiment, mixed polymer dispersions are used as agglomerates, on the latex particles of which hydrophilic groups are only generated by chemical reactions after the polymerization, e.g. B. by saponifying polymerized esters or nitriles of unsaturated acids with at least 3 carbon atoms. If homo- or copolymer dispersions of vinyl esters are chosen as starting materials, then the saponification gives agglomerating agents which have hydroxyl groups as hydrophilic groups. A highly effective agglomerating agent can e.g. B. obtained by partial saponification of a polyvinyl acetate dispersion in an acidic medium.

The composition of the agglomerating agents and the composition can vary within wide limits be adapted to the dispersion to be agglomerated. For dispersions with a predominant The proportion of copolymerized acrylic esters is, for example, a dispersion of the composition 95% ethyl acrylate 5% acrylic acid in question.

The agglomerating agents generally contain more than 1 percent by weight, preferably 2 to 25 percent by weight, monomers (a) copolymerized. In some. In some cases, a salary of 0.1 to 1 percent by weight of monomers (a), especially when these are mixed with monomers (b) are polymerized onto a backbone polymer, even if these are practically none Contains monomers (a) in copolymerized form.

The polymer particles of the agglomerating agent should preferably be more hydrophilic than the dispersed ones Polymer particles of the dispersion to be agglomerated.

The agglomeration is usually achieved by mixing the heated to 35 to 120 ° C dispersion of the to be agglomerated Polymer carried out with that of the agglomerating agent. The type of addition affects the Agglomerating means especially the particle size distribution of the dispersion to be agglomerated, what has a strong influence on the flowability of concentrated dispersions. In general, the particle size distribution is the more slowly you agglomerate, the wider. Particularly narrow and sometimes bimodal Particle size distributions are obtained e.g. B. if the dispersion to be agglomerated with an acrylic acid polymerized-containing agglomerating agent mixes at a pH value below 4 and the pH value the mixture is then quickly adjusted to 7 to 9 by adding alkali while stirring. Particularly broad distributions are obtained by stirring in highly effective agglomerating agents very slowly.

It is often useful to add solvents or plasticizers to the dispersion to be agglomerated, to enable agglomeration at temperatures below 35 C, for example at room temperature. For example, the solvents customary for the polymers are used for this purpose (cf. H ο u b e n-W e y 1, Vol. 14/1, 1961, pp. 78 to 80), which are immiscible with water, in amounts of 10 to 100 parts by weight, based on 100 parts of solid, in question. Suitable plasticizers are e.g. B. Esters of phthalic acid or adipic acid. In some rot, monomers are also suitable solvents, which are then used in can be used in an analogous manner.

ίο In general, an addition of 0.5 to is sufficient 5 parts by weight of the polymer to be agglomerated. Larger amounts are sometimes weak effective agglomerating agents required. Smaller amounts of highly effective agglomerating agents used

it is preferred when it is desired to obtain particularly coarse-particle dispersions.

The process according to the invention gives very stable and coagulate-free dispersions. That Procedure is particularly simple and safe, and according to

ao the process according to the invention, it is possible to use any emulsifiers produced dispersions, also acidic dispersions, to agglomerate. The extent of agglomeration and especially the particle size distribution can be achieved through the choice of the agglomerating agent, the mixing conditions and the degree of saturation the dispersion to be agglomerated can be varied almost as desired with emulsifier.

The agglomerated dispersions are mainly used for the production of coatings, coatings and Suitable for painting.

In the examples, so-called LD values (light transmission values) and surface tensions are given as a measure of the agglomerating effect. The LD value indicates what percentage falls white light through a 1 cm thick layer of a 0.01 ° / ₀ aqueous dispersion to a photocell, compared with pure distilled water under the same conditions. The smaller the LD value, the larger the mean particle size. During agglomeration, the surface tension of the dispersion decreases. The difference in the surface tension of the dispersion before and after the agglomeration is therefore a measure of the reduction in the particle surface that occurred during the agglomeration.

In the examples, the monomers used for the copolymers are abbreviated as follows:

B = n-butyl acrylate Bu Butadiene St = Styrene MM = Methacrylic acid methyl ester N = Acrylonitrile A. Ethyl acrylate As = Acrylic acid MAS = Methacrylic acid MAM = Methacrylamide MAMoI = N-methylol methacrylamide VC ₂ = Vinylidene chloride ME = Methyl acrylate

The parts and percentages given in the following examples are based on weight.

Examples 1 to 9

100 parts of the agglomerated to 30 ° / ₀ sodium väßrigen polymer are heated at pH 9.5 (Examples 1 to 8) or at pH 2.3 (Example 9) in the manner prescribed for the agglomeration temperature.

Then, 9 parts are each of 10 ° / ₀ aqueous dispersions of agglomerating agents, corresponding} Agglomeriermittelpolymerisat parts per 100 parts of solids of the polymer was added. The co-

merisate (substrate) and that of the agglomerating agents used, the temperature and duration of the treatment, the measured LD values and surface tensions before and after the agglomeration are in

The following table shows the dispersed poly-5 to be agglomerated:

No. Substrate Agglomerating agents Tempe
rature duration
in hours LD-wide
(%) end surfaces
tension
(dyn / cm) end ( ⁰ C) Beginning 7th Beginning 41 1 60 pieces, 40 B 95 A, 5As 80 2 89 30th 70 59 2 60St, 4OB 59 Bu, 21 St,
20 MAS ' 80 2 89 3 70 36 3 80 pieces, 20 widths 95 A, 5 As 80 2 89 29 70 67 4th 80 pieces, 20 widths 59 Bu, 21 St,
20 MAS 80 2 89 2 70 40 5 100 pc 59 Bu, 21 St,
20 MAS 120 15th 92 22nd 69 39 6th 50A ₁ 50MM 95 A, 5As 80 4th 95 40 58 37 7th 70N, 30B 95 A, 5As 70 3 89 18th 41 37 8th 40 N, 30 St, 30 B 95 A, 5As 60 2 87 26th 43 60 9 80 pieces, 20 widths 95 A, 5 MAM 80 2 89 70

Examples 10 to 15

100 parts of the aqueous 30 ° / ₀ strength polymer dispersions to be agglomerated, which contain solvents or plasticizers, are added at room temperature with 9 parts of the 10 ° / ₀ strength aqueous agglomerating agent dispersions, corresponding to 3 parts of agglomerating agent per 100 parts of polymer to be agglomerated, and the Adjusted the pH to 9.5 by adding aqueous ammonia solution. The agglomerating agent copolymer is composed of 59 parts of Bu, 21 parts of St and 20 parts of MAS. The composition of the dispersed polymers (substrates) to be agglomerated and the agglomerating agents used, the amount and type of solvent or plasticizer, the duration of the treatment and the LD values before and after agglomeration are summarized in the table below.

Substrate 100 pc By S Hall 10 to 15th duration
in hours LD toilet
Beginning : rt in /O
end No. 100 pc solvent
benzene
(G) Plasticizers
Phthalic acid di-
2-ethylhexyl-
ester 20th 92 52 10 100 pc 9 20th 92 7th 11th 80 pieces, 20 widths 12th - 20th 92 4th 12th 100 pc 15th - 17th 89 7th 13th 89 VC ₈ , 11 ME 25th - 19th 92 39 14th - 12th 10 91 11th 15th - 12th

509 648/6

Claims (1)

Monomers and 99.5 to 75% of its weight water- Claim: Ethylenically forming insoluble homopolymers unsaturated monomers used, with 100 Ge Process for agglomeration of aqueous weight parts of the emulsion polymer with the glass dispersions of emulsion polymers with S temperature above 20 ° C, 1 to 30 parts by weight of the glass temperature above 20 ⁰ C using copolymers of the agglomerating agent, high molecular weight agglomerating agents, thereby and one at Working temperatures that are above that characterized in that the agglomerating glass transition temperature of the polymer to be agglomerated is an aqueous dispersion of an alkali insoluble, which can be reduced from 0.5 to 25% of its io borrowed by solvents and / or plasticizers, lie. Usually one agglomerates by weight of water-soluble homopolymers formed at temperatures between 35 and 120 ⁰ C. The ethylenically unsaturated monomers and the polymerizatioasdispers to be agglomerated 99.5 to 75% of its weight water-insoluble versions can be prepared by the usual process of the emulsifier homopolymers forming ethylenically un- sionspolymerisation using the usual saturated monomers used, with weight parts to 100 15 overall emulsification or dispersion of monomers of the polymers to be agglomerated or Monomer mixtures whose poly-0.1 to 30 parts by weight of the copolymer have merisate glass temperatures above 20 ° C, of the agglomerating agent, and when dispersions of copolymers are made from mono temperatures which are above the glass mers, some of the homopolymers of which are glass transition temperatures having temperatures by the addition of 20 solution below 20 ⁰ C, to forward such and / or plasticizers be lowered selected proportions that the resulting can, a glass transition temperature to be agglomerated are above 20 ⁰ C polymers copolymer. Has. Suitable monomers are e.g. B. olefinic esters unsaturated carboxylic acids containing at least 3 carbon atoms, such as acrylic acid, methacrylic acid, Cro- tonic acid, maleic acid, fumaric and itaconic acid with Alkanols containing 1 to 12 carbon atoms or with cycloalkanols !!, such as cyclohexanol, vinyl esters vkn Poly-saturated carboxylic acids with 3 to 12 carbon atoms produced by emulsion polymerization, such as Merisate dispersions are usually extremely vinyl acetate and vinyl propionate, vinyl aromatic finely divided, and their particle size distribution is different Compounds such as styrene, vinyl toluenes, vinyl xylenes, relatively tight. For some areas of application are «-Methylstyrene, Vinyläthylbenzenes and Chlorstyrenes, however, coarse dispersions are advantageous. Known ethylenically unsaturated nitriles, such as acrylonitrile, as well Fine particles are already present in the case of relatively 1,3-dienes such as butadiene, isoprene, piperilene and 2,3-diggerings Solids contents so viscous that only 35 methylbutadiene and chloroprene, and also vinyl halide, are difficult are to be handled. In contrast, there are nides, such as vinyl chloride or vinylidene chloride. Examples Coarse dispersions can be easily concentrated and are suitable for emulsion copolymers Even with high solids contents they still have a good 60 to 80% styrofoam and 20 to 40% n-butyl acrylate, Fluidity. Styrene and up to about 40% butadiene, 70% acrylonitrile Attempts have therefore already been made to produce coarse dispersions 40 and 30% r-butyl ylate or approximately equal parts sions z. B. by during the ÄthylacryU t and ivlethylmethacrylat.
Polymerization gradually metered in emulsifier. The type of door the preparation of the dispersions In many cases, however, considerable amounts of emulsifiers are formed in the process. This is used for the new aggloliche Amounts of coagulate. In addition, a commenting procedure does not have to be excessive. Important for the extension The degree of gglomeration, however, is the emulsifier. content of the oil dispersion or the degree of saturation of the Emulsion polymerization in the presence of latex with an emulsifier. The degree of saturation can e.g. B. protective colloids,> ·, Ie polyvinyl alcohol or hydroxyl according to H ο ubc η - W ey 1, methods of organic ethyl cellulose, leads to chemistry, especially in the case of vinyl esters. Vol. 14/1, p. 370, by soap titration for the formation of coarse dispersions (cf. German 50 is correct. Patent 10 29 565 is added to the latex in portions), but such protective agents add an aqueous solution of the same emulsifier, and also a colloidal one Increase in viscosity. which was used to make it. The agglomeration process, which after the polymer end point is reached when the surface condensation are carried out, were in different tension of the mixture after further additions not further decreases. Have T ml versions of the emulator gate solution developed. However, these methods are not needed and the sample used initially generally applicable, as they are based on certain emulsifier A ml emulsifier solution. so the saturation level of the gate and pH levels are bound and reflected in their latex Application to other polymer dispersions often A " _{0 /} form considerable amounts of coagulum. 60 '~ ^ 4. 7-' '"' It has now been found that aqueous dispersions of emulsion polymers with glass tempera- The higher the degree of saturation of the polymer dispersion doors above 2O ⁰ C using high molecular weight on the emulsifier, the lower the agglomerating agent is in general particularly easy to agglomerate the action of a certain amount of agglomerating, if an aqueous 65 medium is used as the agglomerating agent. Dispersion of an alkali-insoluble copolymer The polymer content of the to be agglomerated from 0.5 to 25% of its weight water-soluble dispersion can be varied within a wide range. Ethylenically unsaturated homopolymers that form homopolymers In general, the effect of a substance is reduced