CA1068031A - Finely distributed copolymer dispersion and their preparation - Google Patents
Finely distributed copolymer dispersion and their preparationInfo
- Publication number
- CA1068031A CA1068031A CA267,591A CA267591A CA1068031A CA 1068031 A CA1068031 A CA 1068031A CA 267591 A CA267591 A CA 267591A CA 1068031 A CA1068031 A CA 1068031A
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/10—Esters
- C08F220/12—Esters of monohydric alcohols or phenols
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F212/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring
- C08F212/02—Monomers containing only one unsaturated aliphatic radical
- C08F212/04—Monomers containing only one unsaturated aliphatic radical containing one ring
- C08F212/06—Hydrocarbons
- C08F212/08—Styrene
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- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Paints Or Removers (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Polymerisation Methods In General (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
FINELY DISTRIBUTED COPOLYMER DISPERSION AND THEIR
PREPARATION
Abstract of the disclosure:
A process is described by which plastics dispersions of high water and saponification resistance are obtained which, due to their small average particle size diamter of 0.01 to 0.06 µm are especially useful as primers for porous substrates.
In their penetration characteristics, the present dispersions can be compared with conventional solvent-based primers at comparable solids content. The dispersions are obtained in a one-step polymerization process.
PREPARATION
Abstract of the disclosure:
A process is described by which plastics dispersions of high water and saponification resistance are obtained which, due to their small average particle size diamter of 0.01 to 0.06 µm are especially useful as primers for porous substrates.
In their penetration characteristics, the present dispersions can be compared with conventional solvent-based primers at comparable solids content. The dispersions are obtained in a one-step polymerization process.
Description
HOE 75/F 31?
10~803~
Primers for prepaxing and solidifying the substrate for sub-sequent coatings must meet the following requirements:
The binder has to penetrate the substrate thoroughly to ensure its good solidification after drying and to reduce its absorptive power. The primer -thus has to form a good ground coat for the subsequent paint layers, and it must be resistant to water, saponification and atmospheric influence. Solvent containing primers, which hitherto have met these requirements solely, have various disadvantages. The solvent content is dangerous for physiological reasons and because of the fire risk; the tools have to be cleaned with solvents; the molecular weight of the binder has to be maintained within a determined ; range since, at high molecular weight, the viscosity of the primers is too high and does not allow a high binder concentra-~5 tion.
In contrast to solvent containing primers, aqueous plastics dispersions are most advantageous. They do not contain flammable or physiologically intolerable solvents, the tools may be clean-ed with water, and above all, such dispersions, at a high mole-
10~803~
Primers for prepaxing and solidifying the substrate for sub-sequent coatings must meet the following requirements:
The binder has to penetrate the substrate thoroughly to ensure its good solidification after drying and to reduce its absorptive power. The primer -thus has to form a good ground coat for the subsequent paint layers, and it must be resistant to water, saponification and atmospheric influence. Solvent containing primers, which hitherto have met these requirements solely, have various disadvantages. The solvent content is dangerous for physiological reasons and because of the fire risk; the tools have to be cleaned with solvents; the molecular weight of the binder has to be maintained within a determined ; range since, at high molecular weight, the viscosity of the primers is too high and does not allow a high binder concentra-~5 tion.
In contrast to solvent containing primers, aqueous plastics dispersions are most advantageous. They do not contain flammable or physiologically intolerable solvents, the tools may be clean-ed with water, and above all, such dispersions, at a high mole-
2~ cular weight of the binder, may contain a large amount of solids without having to cope with a excessive viscosity. Moreover, re-sidual amounts of water in a paint coating dry easier and more rapidly than solvent residues. Furthermore, provided that their emulsifier/protective colloid systems are compatible, plastics dispersions rnay be blencled in more variations, so that the scope of properti~s may be widely varied by such mixtures of different dispersions~
Despite the obvious advanta~es, aqueous systems have not made their way as primers in the practice. Although water-soluble binders penetrate the substrate thoroughly, they are insufficient-- 2 - ~
10t~8031 ly water-resistant and/or stable to saponification. When the monomers and the emulsifier/protective colloid system is adequately chosen, pl~stics disper-sions give coatings being stable to water and saponification; however, their depth of penetration is insufficient for solidifying and sealing the substrate.
As has been observed by means of copolymerizing optically briBhtening monomers, the hitherto used dispersions scarcely penetrate ca-~ities and capillaries of ; the substrate because of their large average particle diameter, and they do not form practically but a film on the surface.
German Patent Specification No. 1,925,353 proposes a two-step process according to which vinyl ester copolymer dispersions having particle ~; sizes of less than 0.2 ~ are obtained. However, the polymers described are not sufficiently stable to water and saponification, and the two-step manu-facturing process is complicated.
, The present invention is based on the discovery of a process which enables plastics dispersions having an average particle diameter of from about 0.01 to 0.06 ~ to be obtained which yield thoroughly penetration primers stable to water and saponification.
According to the inventionJ there is provided a process for the preparation of finely distributed plastics dispersions particularly suitable for the solidifying primer coating of substrates to be painted, which compri-ses metering a monomer mixture containing (I) from 20 to 80% by weight of styrene and/or methyl methacryl-ate as hardening component provided that methyl methacrylateJ if present in admixture with styreneJ does not exceed 15% by weight of said mixture (II) from 20 to 80% by weight of an acrylic acid ester with linear or branched alcohols having from 2 to 8 carbon atoms and/or a meth-acrylic acid ester with linear or branched alcohols having from 4 to 8 carbon atoms as plastifying componentJ
10~;8031 (III) from 0.1 to 5% by weight of an amide of an ~ unsaturated carboxylic acid, and (IV) from 0.1 to 5% by weight of an a,~-unsaturated monocarbox-ylic acid, the total of components (III) and (IV) being in the range of from 0.2 to 8.5%
by weight,in the form of the pure monomer mixture or a preliminary emulsion, simultaneously with an initiator, into an aqueous liquor containing an anionic emulsifier, said monomers being used in such an amount that the solids con-tent of the final dispersion does not exceed 45% by weight, polymerizing said monomers in said aqueous liquor to form said dispersion, and adjusting said dispersion to a pH of 7 to 10.
The present invention furthermore relates to the plastics dis-persions obtained according to the above process.
The monomers have to be selected according to the rules known to those skilled in the art in such a manner that stable dispersions are obtained and that the film-forming temperatures of the copolymers are in the range known to be favourable for the coating technique, that is, advantageously from about -10 to ~25C.
As hardening component, exclusively styrene is used to particular advantage. When methylmethacrylate is employed in admixture with styrene, its amount should not exceed 15% by weight, relative to the total amount of said mixture.
Examples of the plastifying component are ethylacrylate, propyl-acrylate, isopropylacrylate and the acrylic or methacrylic acid esters of butyl alcohol and 2-ethylhexyl alcohol.
For a modification of the properties of the copolymer, further a,~-unsaturated copolymerizable monomers such as acrylonitrile, hydroxyethyl-methacrylate, hydroxypropyl-methacrylate, vinyl toluene or vinyl xylene may be , ~
~ ~ -4-., ~, .
., . ' ' ,, . . , !
10~i80;~1 concomittsntly us~d.
Amides of ~ unsaturated carboxylic acids, especially acrylamide or methacrylamide, promote the formation of finely distribu~ed dispersions, when they are added to the batch during the polymerization simultaneously with the other monomers. Their concomittant use favours the intended fine distri-bution of the copolymer, so ~hat a preferred embodiment of the invention pro-vides the concomittant use of from 1.5 to 3.5% by weight, relative to the total amount of monomers, of acrylamide or methacrylamide as comonomer.
Incorporation of ~,B-unsaturated monocarboxylic acids into the copolymer increases the stability of the dispersion during its manufacture, storage and application. Acrylic and methacrylic acid in the above-stated amounts of from 0.1 to 5% by weight, relative to the total amount of monomers, are preferred examples.
On the other hand it has to be taken into consideration that the amides of group IV and the carboxylic acids of group V being hydrophilic mono-mers increase the hydrophilic nature of the total molecule. In order not to reduce the water resistance of the primer coats and coatings obtained with the use of the dispersions of the invention to a too large extent, the total amount of the cited monomers should be in a range of from 0.2 to 8.5% by weight. Within these limits, it may be the higher the higher the content of hydrophobic monomers of groups I to III, that is, it may touch the upper limit of the cited range of 0.2 to 8.5% by weight when the other monomers are espe-cially hydrophobic such as styrene, butylacrylate, 2-ethylhexylacrylate or 2-ethylhexylmethacrylate, and the lower limit when the other monomers are less hydrophobic such as methylmethacrylate, ethylacrylate, acrylonitrile or the hydroxy-alkylacrylates.
As hardening monomer of group I, styrene alone is preferably MOE 75~F 317 10~;8031 used. Methylmethacrylate may be employed in a maximum amount of 15 ~ by weight, relative to the total amounts of monomers.
When chosing the kind and amount of monomers of group III, it has to be taken into consideration that they do not deterio--~ 5 rate the stability to water and saponification of the resulting copolymer.
- Examples of suitable monomer combinations are the following (parts by weight):
Butylacryla.e/styrene/acrylamide and/or methacrylic acid~acyl-amide and/or methacrylamide (40 to 80/60 to 15/0.1 to 4/0.1 to 41.
2-Ethylhexylacrylate/styrene/acrylamide and/or methacrylic acid/acrylamide and/or methacrylamide (30 to80/65 to 15/0.1 to 4/0.1 to 4).
', '15 2-Ethylhexylacrylate/methylmethacrylate/acrylamide and/or meth-',; acrylic acid/acrylamide and/or methac~ylamide (30 to 80~65 to ~5/0.1 to 4~0.1 to 4).
Butylacrylate/methylmethacrylate/acrylamide and/or methacr,ylic acid/acrylamide and/or methacrylamide (40 to 80/55 to 15/0.1 to
Despite the obvious advanta~es, aqueous systems have not made their way as primers in the practice. Although water-soluble binders penetrate the substrate thoroughly, they are insufficient-- 2 - ~
10t~8031 ly water-resistant and/or stable to saponification. When the monomers and the emulsifier/protective colloid system is adequately chosen, pl~stics disper-sions give coatings being stable to water and saponification; however, their depth of penetration is insufficient for solidifying and sealing the substrate.
As has been observed by means of copolymerizing optically briBhtening monomers, the hitherto used dispersions scarcely penetrate ca-~ities and capillaries of ; the substrate because of their large average particle diameter, and they do not form practically but a film on the surface.
German Patent Specification No. 1,925,353 proposes a two-step process according to which vinyl ester copolymer dispersions having particle ~; sizes of less than 0.2 ~ are obtained. However, the polymers described are not sufficiently stable to water and saponification, and the two-step manu-facturing process is complicated.
, The present invention is based on the discovery of a process which enables plastics dispersions having an average particle diameter of from about 0.01 to 0.06 ~ to be obtained which yield thoroughly penetration primers stable to water and saponification.
According to the inventionJ there is provided a process for the preparation of finely distributed plastics dispersions particularly suitable for the solidifying primer coating of substrates to be painted, which compri-ses metering a monomer mixture containing (I) from 20 to 80% by weight of styrene and/or methyl methacryl-ate as hardening component provided that methyl methacrylateJ if present in admixture with styreneJ does not exceed 15% by weight of said mixture (II) from 20 to 80% by weight of an acrylic acid ester with linear or branched alcohols having from 2 to 8 carbon atoms and/or a meth-acrylic acid ester with linear or branched alcohols having from 4 to 8 carbon atoms as plastifying componentJ
10~;8031 (III) from 0.1 to 5% by weight of an amide of an ~ unsaturated carboxylic acid, and (IV) from 0.1 to 5% by weight of an a,~-unsaturated monocarbox-ylic acid, the total of components (III) and (IV) being in the range of from 0.2 to 8.5%
by weight,in the form of the pure monomer mixture or a preliminary emulsion, simultaneously with an initiator, into an aqueous liquor containing an anionic emulsifier, said monomers being used in such an amount that the solids con-tent of the final dispersion does not exceed 45% by weight, polymerizing said monomers in said aqueous liquor to form said dispersion, and adjusting said dispersion to a pH of 7 to 10.
The present invention furthermore relates to the plastics dis-persions obtained according to the above process.
The monomers have to be selected according to the rules known to those skilled in the art in such a manner that stable dispersions are obtained and that the film-forming temperatures of the copolymers are in the range known to be favourable for the coating technique, that is, advantageously from about -10 to ~25C.
As hardening component, exclusively styrene is used to particular advantage. When methylmethacrylate is employed in admixture with styrene, its amount should not exceed 15% by weight, relative to the total amount of said mixture.
Examples of the plastifying component are ethylacrylate, propyl-acrylate, isopropylacrylate and the acrylic or methacrylic acid esters of butyl alcohol and 2-ethylhexyl alcohol.
For a modification of the properties of the copolymer, further a,~-unsaturated copolymerizable monomers such as acrylonitrile, hydroxyethyl-methacrylate, hydroxypropyl-methacrylate, vinyl toluene or vinyl xylene may be , ~
~ ~ -4-., ~, .
., . ' ' ,, . . , !
10~i80;~1 concomittsntly us~d.
Amides of ~ unsaturated carboxylic acids, especially acrylamide or methacrylamide, promote the formation of finely distribu~ed dispersions, when they are added to the batch during the polymerization simultaneously with the other monomers. Their concomittant use favours the intended fine distri-bution of the copolymer, so ~hat a preferred embodiment of the invention pro-vides the concomittant use of from 1.5 to 3.5% by weight, relative to the total amount of monomers, of acrylamide or methacrylamide as comonomer.
Incorporation of ~,B-unsaturated monocarboxylic acids into the copolymer increases the stability of the dispersion during its manufacture, storage and application. Acrylic and methacrylic acid in the above-stated amounts of from 0.1 to 5% by weight, relative to the total amount of monomers, are preferred examples.
On the other hand it has to be taken into consideration that the amides of group IV and the carboxylic acids of group V being hydrophilic mono-mers increase the hydrophilic nature of the total molecule. In order not to reduce the water resistance of the primer coats and coatings obtained with the use of the dispersions of the invention to a too large extent, the total amount of the cited monomers should be in a range of from 0.2 to 8.5% by weight. Within these limits, it may be the higher the higher the content of hydrophobic monomers of groups I to III, that is, it may touch the upper limit of the cited range of 0.2 to 8.5% by weight when the other monomers are espe-cially hydrophobic such as styrene, butylacrylate, 2-ethylhexylacrylate or 2-ethylhexylmethacrylate, and the lower limit when the other monomers are less hydrophobic such as methylmethacrylate, ethylacrylate, acrylonitrile or the hydroxy-alkylacrylates.
As hardening monomer of group I, styrene alone is preferably MOE 75~F 317 10~;8031 used. Methylmethacrylate may be employed in a maximum amount of 15 ~ by weight, relative to the total amounts of monomers.
When chosing the kind and amount of monomers of group III, it has to be taken into consideration that they do not deterio--~ 5 rate the stability to water and saponification of the resulting copolymer.
- Examples of suitable monomer combinations are the following (parts by weight):
Butylacryla.e/styrene/acrylamide and/or methacrylic acid~acyl-amide and/or methacrylamide (40 to 80/60 to 15/0.1 to 4/0.1 to 41.
2-Ethylhexylacrylate/styrene/acrylamide and/or methacrylic acid/acrylamide and/or methacrylamide (30 to80/65 to 15/0.1 to 4/0.1 to 4).
', '15 2-Ethylhexylacrylate/methylmethacrylate/acrylamide and/or meth-',; acrylic acid/acrylamide and/or methac~ylamide (30 to 80~65 to ~5/0.1 to 4~0.1 to 4).
Butylacrylate/methylmethacrylate/acrylamide and/or methacr,ylic acid/acrylamide and/or methacrylamide (40 to 80/55 to 15/0.1 to
3/0.1,to 3~.
The polymerization must be performed in the presence of an anionic emulsifier, for example, alkali metal salts of sul-uric acid semi-esters o alkyl-phenols or alcohols, which may be oxethylated;or alkyl or aryl sulfonates.
Preferred anionic emulsifiers are alkali metal salts of-sulfurlc aci~ semi-esters of a nonyl phenol reacted with from 4 ;~29 to 5 moles of ethylene oxide; sodium lauryl sulfate, sodium lau-.
~06so31 ryl ethoxvlate sulfate con-taining from 2 to 5 moles of ethylene oxide; sodium clodecylbenzene sul~onate and secondary sodium alkane sulfonates having from 8 to 20 carbon atoms in the carbon chain.
The amount of a~ionic emulsifier may be from 0.5 to 10 ~
by weight, preferably from 2 to 8 % by wei~ht, relative to the total monomers. Generally, an increase of the amount of anionic emulsifier used brings about a decrease of particle size.
In order to increase the stability of the dispersions, non-ionic emulsifiers, such as ethoxylated alkylphenols or fatty alcohols, for example, nonylphenols having from 4 to 30 mols of ethylene oxide may be employed in addition and in admixtuxe with the anionic emulsifier. When selecting the emulsifiers and monomers to be used as well as the preparation process, care has to be taken that dispersions are obtained which do not tend to formation of aggregates neither after manufacture nor after dilution with water, since formation of larger aggregates may decrease the penetrating po~er when the finely distributed plastics dis~ersions are used for impregnation and primer coating.
Suitable initiators are the usual inorganic per-compounds such asa~mx~um persulfa~e, potassium persulfate, sodium persulfate, or organic peroxides such as benzoyl peroxide, organic peresters such as perisopivalate. Advantageously the initiators also com-prise a red~cing agent suçh as sodium bisulfite, hydrazine, or hydroxylamine It is preferable to use, in addition to the ini-tiators, catalytic quantities of accelerators such as salts of iron, cobalt, cerium and/or vanadium; preference is given to the -use of alkali or ammonium peroxidisulfates.
- ~9 The polymerization temperature may be from 10 to 100 C, ~ 7 ~ ~ -~0~803~
preferably ~rom 30 to 90 C.
The solids content of the dispersions is from 20 to 45 %, after their manufacture.
It is advantageous for the preparation of the dispersions having an especially fine particle size distribution according to the invention when the polymerization is carried out at low solids concentration, since reduction of the solids concen-tration generally gives finely distributed dispersions. As Table 1 shows, latices containing coarser particles have less pentrating power and less solidifying effect than the finely distributed dispersions. In the case where finely distributed dispersions contain an amount of coarser particles because of a broad distribution of particle sizes, this amount of coarser particles does not contribute to impart a solidifying effect and a good penetrating power to the dispersion. Therefore, plastics dispersions having a narrow distribution of particle sizes are a preferred embodiment of the present invention.
After polymerization, the pH of the finely distributed dispersions is adjusted to a pH of from 7 to 10, preferably from 7.5 to 9, by means of alkali, ammonia or amines. When dispersions having a low solids content are obtained, this solids content may be increased by vacuum distillation without deteriorating the extrordinary fine distribution of the dispersions.
The polymerization may be carried out as follows:
from 30 - 50 % of the water and from 20 - 50 % of the anionic emulsiier together with from 10 - 50 ~ of the non-ionic emulsi-fier are precharged. A preliminary emulsion is prepared from the monomers, the remaining part o~ water and the rest of emulsi-fiers, and is metered during 1 to 3 hours into the liquor formed ~ 8 ~
.. .. . -: :- i - .
. :: ~ - . - . . , ~ ~ . ............... . . . . ... .. . .
. . . . . ..
10~;8031 ~
from the ~ater ~nd emulsiier which has been heated to 50 - 90 C.
- The qunatitative ratio of monomers to water is chosen in such a manner that the resulting dispersion contains from 20 to 45 %
of solids.
The amount of anionic emulsifier has to be in a range of from 2 to 8 %, relative to the monomers, depending on the solids content intended.
The reaction batch is then stirred, and, after termination of the feed, the whole batch is stirred for another 1 - 3 hours at a temperature of from 70 to 90 C. The initiator is pre-ferably added as a 1 to 5 per cent aqueous solution during the addition of the emulsion. Subsequently, the pH is adjusted to 7.5 to 9 by means of ammonia, aliphatic amines or alkali metal hydroxides.
The addition of the monomer emulsion is not essential for preparing the plastics dispersions having fine particle sizes:
they may also be obtained by metering the monomer mixture into a liquor containing lll the water and the emulsifiers. When plastics dispersions are to be used for primer coatings and im- - ~
pregnation, the solids content of the dispersions has a decisive ~;
influence on the penetrating depth, the soldifying effect and the reduction of absorptive power of the treated substrates.
Dilute dispersions penetrate deeper into the substrate pores than concentrated dispersions. When using concentrated dispersions, only some of the latex particles penetrate into .
the substrate pores, the others forming a film on the substrate surface. ~ -~
Therefore, o~ application~concehtrated dispersions reduce :~
_ g _ ~._ .. . . ..... .
... ,: . . - . :. : . . . : . .. .. ~.
10~8031 the absorpti~n of the substrate to a very hic~h degre~, while dilute dispersions have only a poor reducing effect on the ab-sorption o~ the substrate.
The solidifying effect de~ends both on the nature of the polymer and on the amount of polymer per unit area of the treat-ed surface. ~lthough dilute dispersions penetrate deeply into the substrate, the amount o~ plastics material per unit area is relatively low. In the case of concentrated dispersions, that part oftHe polymer which remains on the surface after dry-ing does not contribute to the solidification of deeper layers.
It is therefore possible to adjust the ratio of penetrating depth, solidification and sealing of the surface, and to adapt these parameters to the various substrates encountered in prac-tice by a corresponding choice of the solids content. Using the dispersions of the invention, good results are obtained at solids amounts of from 5 to 25 % by weight, preferably-from 10 to 20 % by weight. An advantage of the dispersions of the in-vention resides in t~e fact that within a relatively wide con-centration range an especially favorable ratio of good penetrat-ing depth and good solidification can be obtained by a high spe-cific plastics amount in the treated surface, when the latex particles have a mean particle size of from 0.01 to 0.0~ ~m (determination of the particle size according to the light scattering method and electron microscopy).
As is current practice for dispersion paints, auxiliaries may be added. Examples of such auxiliaries are solvents for improving film formation and for lowering the film-forming tem-perature, plasticizers, defoamers, preservatives, surface-active 29 substances for improving wetting, and pigments or soluble dye-,~ ,,,, : : ".
HOE 75/~ 317 iO~;8031 stufEs for t nyein~.
The de~ree of penetration may be tes-ted by different methods.
The material to be submitted to such a test may for example be applied to the chosen substrate, for example, by brushing, pour-ing or dropping. After drying, the penetrated material may then be identified by means of its cross section. If dissolved resins are us~d, they may be colored by soluble dyestuffs. This method can however lead to spurious results, when the aqueous phase is colored simultaneously. Since the aqueous phase of most: dispersions penetrates deeper than the latex particles, the colored zone oE the cross section may not correspond to the actual penetration of the particles.
In order to prove the improved penetration of the disper-sions of the invention copolymer dispersions containing optical brighteners were prepared by copolymerization with vinyl-sulfo-nyl-pyrazoline-brighteners at concentration rates of from 0.01 - 0.05 ~ (based on the monomers). The polymers so prepared contained in their latex particle a random distribution of brightener molecules as structural units, all over the macro- -molecule, and so the optical brightener could not be extracted from the polymer. The polymer is therefore located in the sub- '! "' strate exactly where the optical brightener shows the charac-teristic fluorescence under UV radiation. The copolymer disper sions containing optical brighteners and having fine particle sizes were applied onto a number of substrates such as wooden plates, calcareous sandstone, plaster plates, plastering lime, plastering concrete, filler coating, unglazed clay plates, gas concrete, brick etc. The dr~ specimens were checked under 29 UV radiation ancl the depth o~ their penetration measured on the ~06803~
planes of section.
Other methods for deternlining the penetration of the poly-mer are also known. One suitable method consists, for example, of burning off a plane section of coated or impregnated sub-strate with a bunsen burner, the polymer being the distinguished by a grey discoloration. Sections of acid-resistant substrates may also be coated with concentrated sulfuric acid in order to identify the penetration of the polymer. These experiments showed that the finely distributed plastics dispersions of the invention, at the same solids content, penetrate to the same depth and solidify as well as known binders in solvent-contain-ing systems, and that the penetration depth and degree of soli-dification was much greater than that of dispersions with com-parable polymer structure and average particle size diameters of more than 0.06 ~m.
The superiority of dispersions having particle sizes of less than 0.06 ~m was proved especially by the fact that at relatively high solids contents of, for example, from 15 to 20 per cent by weight which allow the application of a large amount of plastic material per unit area in one single operation, the finely distributed dispersions still penetrate almost con~pletely into the substrate, where they contribute to solidification and improved anchorage for subsequent paint coatings. Dispersions having larger particle sizes do not penetrate into the substrate to a substantial extent, but merely form a film on the surface.
A further test allows to study not only the penetration of the dispersion but also the degree of solidification obtain-ed from a certain quantity of binder, by reacting the dispersion ~9 with fine-grained, loose material. This method also has the ad-10~803i v~nt~ge that the materlal produces a compound of the grained m~terial in the pene~ration zc~ne after drying. The solidified core can be easily removed and weighed. Its weight is a re-ference for measuring the penetrating ability and the solidi~y-ing e~fect. This test simulates, for example, the solidifica-tion of surfacejof old, weather-beaten construction parts.
For performing the test, flat recepticles were filled with quartz powder (average analysis: 50 % ~ 40~m). Where the material was to be submitted to the test, a hemispherical groove having a diameter of 2.5 cm was formed by using a stamp. 2 ml of the dispersion was dropped into this groove, and after having allowed the Eilling layer to dry at room temperature for four hours, it was placed in a drying cabinet at SO C for another 15 hours. The results of these tests are shown in Table 1. The ~
tests were carried out on plastics dispersions according to -the invention having particle sizes from 0.01 to 0.06 ~m, which were prepared according to the Examples 1 to 6.
Dispersions having particle size D~ 0.08 ~m were tested ::. . .
for comparison, these dispersions being based on various monomer systems and commercial polymers in organic solvents which are recommended for penetrative primer coatings.
The results o~ the tests show that the highest core weight and thus the best penetrating ability combined with a high degree of solidification is obtained with dispersions according to the invention and with the polymer solutions in organic sol-vents (Table 1); the results obtained from aqueous plastics dispersions having larger average particle diameters /D> 0.1 ~m) being clearly inferior to those achieved with the finely distri-29 buted dispersions ac_ording to the invention.
, :...... :.~ . ... .. :: - . : ............... ... . . : - .
: .: .. : ::: : : ::: : .,. ,: : , . : . : : ::: : .: : .i. -, . : :. . , llOE 75/F 317 10~8031 ~ further recluiremerlt to be met by primer coatings having a penetrative effect is thelr capabi]ity of ensuring good ad-hesion to paints subsequently applied onto the coated substrate and to provide a good anchoraqe betweerl-the paint and the sub-strate. This requirement must still be met even in the case where the paint is applicd to primer layers of uneven thickness which may be due to irregular absorption of the subs-trate after many application of the primer.
This requirement was tested by applying about 12 % dispersions having finest grain sizes according to the invention three times, separated by intermediate drying, on asbestos cement plates as substrate. After drying in air for three days, the primer coat was painted with a dispersion paint containing a styrene/butyl acrylate dispersion as binder and having a ratio of dispersion to pigment filler mixture of 1:1.6. A reinforcing cloth strip -of polyethylene terephthalate was imbedded in the fresh paint and then painted with the same paint after drying of the first paint coat.
The adhesion between the primer coat and the substrate, and between the primer coat and the dispersion paint coat was tested by trying to remove the cloth strip. ~ood adhesion was found reyardless of whether it was peeled off dry or wetted by storing under water and re-drying. The same results were obtained from tests perfc~rmed according to Examples 1 to 6 with soft binder 2S films which had adjus-table monomer ratios, or with hard binder f1lms of polymers. Without exception, the cloth strips could be pulled off the dispersion paint coating leaving the lattice-type fabric structure embossed on the paintlayer;
29 however, no paint was taken off the substrate or the primer coat ~ . . . .
. . .
in this operation. The same resul-ts were obtained by cross-cutting the dried dispersion paint coating and trying to pull the disper-si.on paint film off the cross-cut squares by means of an adhesive tape. The paint layer did not come off either.
The following Examples illustrate the preparation of finely distributed dispersions of the invention.
E X A M P L E 1:
.. .. _ . . :
A stable monomer emulsion is prepared from styrene 134 parts by weight .
butylacrylate 200 parts by weight acrylamide .4.5 parts by weiyht methacrylic acid 12.0 parts by weight sodium salt of a secondary alkyl-sulfonate (C12-C16)10 parts by weight ..
reaction product of nonyl-phenol with 10 ~ 12 moles of ethylene oxide 5.0 parts by weight water 400 parts by weight The emulsion is metered i.nto a liquor of 230 parts by weight of water, 2 parts by weight of a non-ionic emulsifier and 8 parts ~ ~.
by weight of an ionic emulsifier. Simultaneously to the dosage of the emu~sion, a sol.ution of 2 parts by weight o~ ammonium persu~ate in 40 parts by weiyht o.E water is added.
The mean particle size of the dispersion adjusted to a pH
of 8 - 9 is 0.036 ~m.
E X A M P I. E 2:
Copolymer dispersions containing an optical brightener and having fine particles are obtained by dissolving additionally 0.1 part by weight of a vinyl-sulfonyl-pyrazoline brightener (cf.
29 German Offenleyungsschrift No. 2 011 552) in the rnonomer mixture - 15 ~
.. . . . . :: . : : : , . , . ~ .
~ -, ,,, -,, . , . :
HOE 7~F 317 of E~am~le 1, and subsec~uently preparing the plastics dispersions as before.
Both the aqueou~ plastics dispersion and the dry polymer film exhibit a chara~teristic blue fluorescence under UV radia-tion which allows detection of even very small polymer amounts in the different substrates. Fractionating by gel permeation chromatography shows that the optical brightener is incorporated uniformly in the polymer, i.e. no accumulations are formed in certain ranges of molecular weight. The a~Terage particle size of the copolymer dispersion containing the optical brightener is 0.038 ~m.
E X A M P L E 3:
A monomer mixture comprising styrene 170 parts by weight butylacrylate 170 parts by weight acrylamide 4 parts by weight methacrylic acid 10 parts by weight is metered into a liquor comprising 680 parts by weight of water, 25 parts by weight of a secondary sodium alkyl sulfonate (C12-C16) and 10 parts by weight of the reaction product of nonyl~phenol and from 8 - 12 moles of ethylene oxide.
A solution of 2 parts by weight of ammonium persulfate in 40 parts by weight of water is used as initlator. The average particle size diameter is 0.038 ~m.
E X A M P L E 4:
~ stable monomer emulsion is prepared from styrene 3600 parts by weight ~utyl acrylate 3600 parts by weight - 2g acrylam;`de 100 parts by weight ~ .
.
flOE 75/F 317 10~;80;~
methdcrylic ac.id 250 parts by ~eight sodium lauryl sulEate 340 parts by weight reaction product of nonyl~phenol with 8 - 12 moles of ethylene oxlde180 parts by weight water 10,000 parts by weight The emulsion is metered into a liquor of 5000 parts by weight of water, 80 parts by we;.ght of the non-ionic emulsifier and 280 parts by weight of the anionic emulsifier. A solution of 40 parts ~-by weight of ammonium persulfate in 900 parts by weight of water is metered in simultaneously. The average particle diameter of ~ . :
the dispersion adjusted to a pH of 8 - 9 is 0.042 ~m.
The dispersion can be concentrated in the same reaction vessel, under water jet vacuum, to a solids content of about 45 %.
The average particle size remains 0.042 ~m.
E X A M P L E 5: ;
A monomer mixture of methylmethacrylate 130 parts by weight butylacrylate . 200 parts by weight acrylic acid 12 parts by weight acrylamide 4 parts by weight is metered into a liquor of 660 parts by weight of water, 20 parts by we.ight of sodium lauryl ethoxylate-sulfate (with 2 - 5 moles of ethylene oxide) and 8 parts by wei.ght of a reaction product of nonyl-phenol and 6 - 10.moles of ethylene oxide. A solution of 3 parts by weight of potassium persulfate in 30 parts by weight of water is used as initiator. The average particle size is 0.04.1 ~m.
2~ Irhe composition of the liquor is as in Example 5.
. - 17 -: . . . .
- - . . . - :. .. . . .
: . .. , . - , . . . ~ .. ; -:
: ~ . - .. , : ~ .
IIOE` ~ 3 ~ 7 ~0~8~31 rhe m~ o~ r r~li xt~re comprises methylmethacrylat~100 parts by weight b~Itylacrylate230 parts by w~ight acrylic ac.i.d13 parts by weight ac~ylamic1e5 parts by wei.ght 2 parts by weight of potasslum persulfate dissolved in 20 parts ~y weight of water are employed as inltiator. The average par-ticle diameter is 0.045 ~m.
E X A M P ~. E 7 _ _ ~ _ _ A stable monomer emulsion is prepared from styrene 170 parts by weight butylacryla-te 170 parts by weight sodium lauryl sulfate15 parts by weight reaction product of nonyl-phenol with 8 - 12 moles of ethylene oxide5 parts by weight water 450 parts by weight The emulsion is metered into a liquor consisting of 200 parts by weight of wa-ter, 3 parts by weight of the non-ionic emulsifier and 8 parts by weiyht of the ioni.c emulsifier~ A
solution of 3 parts by weight of ammonium persulfate in 30 parts by weight of wat~r is simultaneously metered in.
The average parti.~le size of the dispersi.on being adjusted to ~I 8 - 9 is 0.060 ~m.
~ TqVE: EX~IPLE A: .
A copolymer dispersion is prepared comp~ising vinyl acetate 70 parts by weight Versatic(R)-~OC-acid vinyl ester 25 parts by weight srotonic acid 5 parts by wei.ght 29 with an anionic emulslfier and an inorganic per-compound and . .- . ~ . . :i,,,. .. . . ,, , ,; , . . . .
` 10~;8031 CO~ li.n~ L ta,~ 10 - 50 ~ o solids.
Tlle avera~Je particle size is 0.620 ~m.
COMPAR~ IVE EX MrÆE - :
A copolymer ~ispersion is prepared according to Æxample A~
consisting of vinyl acetate 70 parts by weight butylacrylate 30 parts by weight.
The average particle size is 0.270~m.
COMPARATlVÆ EXAMPLE C:
A copolymer dispersion is prepared, comprising styrene50 parts by weight butylacrylate 50 parts by weight acrylic acid2 parts by weight methacrylic acid 5 parts by weight acrylamide 3 parts by weight with a mixture of anionic and non-ionlc emulsifiers and an in-organic per-compound.
The average particle size is 0.150 ~m.
COMPARATIVE EXAMPLE D:
A copolymer composed of vinyl acetate 70 parts by weight maleic acid dibutylester 30 parts by weight is dissolved in ethyl acetate to yield a 60 % solution. The viscosity at 20 C acco~ding to H~ppler (DIN 53 015) is 80 P.
a primer having penetrative effect is prepared from this solution in the following manner:
60 % copolymer solution in ethyl acetate 28 parts by weight Shellsol A (trade mark) 62 parts by weight ~`~ ethyl~lycol acetate l0 parts by weight .
10~803~
?~ r \~" 1~ r,~
Froma copol~mer comprising vinyl toluene 85 parts by weight acrylic acid-2-ethy].-he~yl ester15 parts by weight 5 having a viscosity of about 60 cP at 20 C according to Hoppler in a 30 8 solution in xylene, a primer coating solution is pre-pared in the Eollowing manner:
copolymer 170 parts by weight white spirit 545 parts by weight Shellsol A (trade mark) 285 parts hy weight '-:
- 20 ~
' HOE 75~'F 317 10~8~
T ~ B ~, E
_ .,, Penetration test_in ~artz sand fill.i~s ~x- ~ver~e particle size (~Im) core weiyht (~) after appli-ample (according to light scatter- cation of 2 ml of a 17 %
.ng ~ethod) and 11 ~ dispersion 1 0.036 l2.3 13.6 2 0.038 11.8 12.5 3 0.038 12.1 12.8
The polymerization must be performed in the presence of an anionic emulsifier, for example, alkali metal salts of sul-uric acid semi-esters o alkyl-phenols or alcohols, which may be oxethylated;or alkyl or aryl sulfonates.
Preferred anionic emulsifiers are alkali metal salts of-sulfurlc aci~ semi-esters of a nonyl phenol reacted with from 4 ;~29 to 5 moles of ethylene oxide; sodium lauryl sulfate, sodium lau-.
~06so31 ryl ethoxvlate sulfate con-taining from 2 to 5 moles of ethylene oxide; sodium clodecylbenzene sul~onate and secondary sodium alkane sulfonates having from 8 to 20 carbon atoms in the carbon chain.
The amount of a~ionic emulsifier may be from 0.5 to 10 ~
by weight, preferably from 2 to 8 % by wei~ht, relative to the total monomers. Generally, an increase of the amount of anionic emulsifier used brings about a decrease of particle size.
In order to increase the stability of the dispersions, non-ionic emulsifiers, such as ethoxylated alkylphenols or fatty alcohols, for example, nonylphenols having from 4 to 30 mols of ethylene oxide may be employed in addition and in admixtuxe with the anionic emulsifier. When selecting the emulsifiers and monomers to be used as well as the preparation process, care has to be taken that dispersions are obtained which do not tend to formation of aggregates neither after manufacture nor after dilution with water, since formation of larger aggregates may decrease the penetrating po~er when the finely distributed plastics dis~ersions are used for impregnation and primer coating.
Suitable initiators are the usual inorganic per-compounds such asa~mx~um persulfa~e, potassium persulfate, sodium persulfate, or organic peroxides such as benzoyl peroxide, organic peresters such as perisopivalate. Advantageously the initiators also com-prise a red~cing agent suçh as sodium bisulfite, hydrazine, or hydroxylamine It is preferable to use, in addition to the ini-tiators, catalytic quantities of accelerators such as salts of iron, cobalt, cerium and/or vanadium; preference is given to the -use of alkali or ammonium peroxidisulfates.
- ~9 The polymerization temperature may be from 10 to 100 C, ~ 7 ~ ~ -~0~803~
preferably ~rom 30 to 90 C.
The solids content of the dispersions is from 20 to 45 %, after their manufacture.
It is advantageous for the preparation of the dispersions having an especially fine particle size distribution according to the invention when the polymerization is carried out at low solids concentration, since reduction of the solids concen-tration generally gives finely distributed dispersions. As Table 1 shows, latices containing coarser particles have less pentrating power and less solidifying effect than the finely distributed dispersions. In the case where finely distributed dispersions contain an amount of coarser particles because of a broad distribution of particle sizes, this amount of coarser particles does not contribute to impart a solidifying effect and a good penetrating power to the dispersion. Therefore, plastics dispersions having a narrow distribution of particle sizes are a preferred embodiment of the present invention.
After polymerization, the pH of the finely distributed dispersions is adjusted to a pH of from 7 to 10, preferably from 7.5 to 9, by means of alkali, ammonia or amines. When dispersions having a low solids content are obtained, this solids content may be increased by vacuum distillation without deteriorating the extrordinary fine distribution of the dispersions.
The polymerization may be carried out as follows:
from 30 - 50 % of the water and from 20 - 50 % of the anionic emulsiier together with from 10 - 50 ~ of the non-ionic emulsi-fier are precharged. A preliminary emulsion is prepared from the monomers, the remaining part o~ water and the rest of emulsi-fiers, and is metered during 1 to 3 hours into the liquor formed ~ 8 ~
.. .. . -: :- i - .
. :: ~ - . - . . , ~ ~ . ............... . . . . ... .. . .
. . . . . ..
10~;8031 ~
from the ~ater ~nd emulsiier which has been heated to 50 - 90 C.
- The qunatitative ratio of monomers to water is chosen in such a manner that the resulting dispersion contains from 20 to 45 %
of solids.
The amount of anionic emulsifier has to be in a range of from 2 to 8 %, relative to the monomers, depending on the solids content intended.
The reaction batch is then stirred, and, after termination of the feed, the whole batch is stirred for another 1 - 3 hours at a temperature of from 70 to 90 C. The initiator is pre-ferably added as a 1 to 5 per cent aqueous solution during the addition of the emulsion. Subsequently, the pH is adjusted to 7.5 to 9 by means of ammonia, aliphatic amines or alkali metal hydroxides.
The addition of the monomer emulsion is not essential for preparing the plastics dispersions having fine particle sizes:
they may also be obtained by metering the monomer mixture into a liquor containing lll the water and the emulsifiers. When plastics dispersions are to be used for primer coatings and im- - ~
pregnation, the solids content of the dispersions has a decisive ~;
influence on the penetrating depth, the soldifying effect and the reduction of absorptive power of the treated substrates.
Dilute dispersions penetrate deeper into the substrate pores than concentrated dispersions. When using concentrated dispersions, only some of the latex particles penetrate into .
the substrate pores, the others forming a film on the substrate surface. ~ -~
Therefore, o~ application~concehtrated dispersions reduce :~
_ g _ ~._ .. . . ..... .
... ,: . . - . :. : . . . : . .. .. ~.
10~8031 the absorpti~n of the substrate to a very hic~h degre~, while dilute dispersions have only a poor reducing effect on the ab-sorption o~ the substrate.
The solidifying effect de~ends both on the nature of the polymer and on the amount of polymer per unit area of the treat-ed surface. ~lthough dilute dispersions penetrate deeply into the substrate, the amount o~ plastics material per unit area is relatively low. In the case of concentrated dispersions, that part oftHe polymer which remains on the surface after dry-ing does not contribute to the solidification of deeper layers.
It is therefore possible to adjust the ratio of penetrating depth, solidification and sealing of the surface, and to adapt these parameters to the various substrates encountered in prac-tice by a corresponding choice of the solids content. Using the dispersions of the invention, good results are obtained at solids amounts of from 5 to 25 % by weight, preferably-from 10 to 20 % by weight. An advantage of the dispersions of the in-vention resides in t~e fact that within a relatively wide con-centration range an especially favorable ratio of good penetrat-ing depth and good solidification can be obtained by a high spe-cific plastics amount in the treated surface, when the latex particles have a mean particle size of from 0.01 to 0.0~ ~m (determination of the particle size according to the light scattering method and electron microscopy).
As is current practice for dispersion paints, auxiliaries may be added. Examples of such auxiliaries are solvents for improving film formation and for lowering the film-forming tem-perature, plasticizers, defoamers, preservatives, surface-active 29 substances for improving wetting, and pigments or soluble dye-,~ ,,,, : : ".
HOE 75/~ 317 iO~;8031 stufEs for t nyein~.
The de~ree of penetration may be tes-ted by different methods.
The material to be submitted to such a test may for example be applied to the chosen substrate, for example, by brushing, pour-ing or dropping. After drying, the penetrated material may then be identified by means of its cross section. If dissolved resins are us~d, they may be colored by soluble dyestuffs. This method can however lead to spurious results, when the aqueous phase is colored simultaneously. Since the aqueous phase of most: dispersions penetrates deeper than the latex particles, the colored zone oE the cross section may not correspond to the actual penetration of the particles.
In order to prove the improved penetration of the disper-sions of the invention copolymer dispersions containing optical brighteners were prepared by copolymerization with vinyl-sulfo-nyl-pyrazoline-brighteners at concentration rates of from 0.01 - 0.05 ~ (based on the monomers). The polymers so prepared contained in their latex particle a random distribution of brightener molecules as structural units, all over the macro- -molecule, and so the optical brightener could not be extracted from the polymer. The polymer is therefore located in the sub- '! "' strate exactly where the optical brightener shows the charac-teristic fluorescence under UV radiation. The copolymer disper sions containing optical brighteners and having fine particle sizes were applied onto a number of substrates such as wooden plates, calcareous sandstone, plaster plates, plastering lime, plastering concrete, filler coating, unglazed clay plates, gas concrete, brick etc. The dr~ specimens were checked under 29 UV radiation ancl the depth o~ their penetration measured on the ~06803~
planes of section.
Other methods for deternlining the penetration of the poly-mer are also known. One suitable method consists, for example, of burning off a plane section of coated or impregnated sub-strate with a bunsen burner, the polymer being the distinguished by a grey discoloration. Sections of acid-resistant substrates may also be coated with concentrated sulfuric acid in order to identify the penetration of the polymer. These experiments showed that the finely distributed plastics dispersions of the invention, at the same solids content, penetrate to the same depth and solidify as well as known binders in solvent-contain-ing systems, and that the penetration depth and degree of soli-dification was much greater than that of dispersions with com-parable polymer structure and average particle size diameters of more than 0.06 ~m.
The superiority of dispersions having particle sizes of less than 0.06 ~m was proved especially by the fact that at relatively high solids contents of, for example, from 15 to 20 per cent by weight which allow the application of a large amount of plastic material per unit area in one single operation, the finely distributed dispersions still penetrate almost con~pletely into the substrate, where they contribute to solidification and improved anchorage for subsequent paint coatings. Dispersions having larger particle sizes do not penetrate into the substrate to a substantial extent, but merely form a film on the surface.
A further test allows to study not only the penetration of the dispersion but also the degree of solidification obtain-ed from a certain quantity of binder, by reacting the dispersion ~9 with fine-grained, loose material. This method also has the ad-10~803i v~nt~ge that the materlal produces a compound of the grained m~terial in the pene~ration zc~ne after drying. The solidified core can be easily removed and weighed. Its weight is a re-ference for measuring the penetrating ability and the solidi~y-ing e~fect. This test simulates, for example, the solidifica-tion of surfacejof old, weather-beaten construction parts.
For performing the test, flat recepticles were filled with quartz powder (average analysis: 50 % ~ 40~m). Where the material was to be submitted to the test, a hemispherical groove having a diameter of 2.5 cm was formed by using a stamp. 2 ml of the dispersion was dropped into this groove, and after having allowed the Eilling layer to dry at room temperature for four hours, it was placed in a drying cabinet at SO C for another 15 hours. The results of these tests are shown in Table 1. The ~
tests were carried out on plastics dispersions according to -the invention having particle sizes from 0.01 to 0.06 ~m, which were prepared according to the Examples 1 to 6.
Dispersions having particle size D~ 0.08 ~m were tested ::. . .
for comparison, these dispersions being based on various monomer systems and commercial polymers in organic solvents which are recommended for penetrative primer coatings.
The results o~ the tests show that the highest core weight and thus the best penetrating ability combined with a high degree of solidification is obtained with dispersions according to the invention and with the polymer solutions in organic sol-vents (Table 1); the results obtained from aqueous plastics dispersions having larger average particle diameters /D> 0.1 ~m) being clearly inferior to those achieved with the finely distri-29 buted dispersions ac_ording to the invention.
, :...... :.~ . ... .. :: - . : ............... ... . . : - .
: .: .. : ::: : : ::: : .,. ,: : , . : . : : ::: : .: : .i. -, . : :. . , llOE 75/F 317 10~8031 ~ further recluiremerlt to be met by primer coatings having a penetrative effect is thelr capabi]ity of ensuring good ad-hesion to paints subsequently applied onto the coated substrate and to provide a good anchoraqe betweerl-the paint and the sub-strate. This requirement must still be met even in the case where the paint is applicd to primer layers of uneven thickness which may be due to irregular absorption of the subs-trate after many application of the primer.
This requirement was tested by applying about 12 % dispersions having finest grain sizes according to the invention three times, separated by intermediate drying, on asbestos cement plates as substrate. After drying in air for three days, the primer coat was painted with a dispersion paint containing a styrene/butyl acrylate dispersion as binder and having a ratio of dispersion to pigment filler mixture of 1:1.6. A reinforcing cloth strip -of polyethylene terephthalate was imbedded in the fresh paint and then painted with the same paint after drying of the first paint coat.
The adhesion between the primer coat and the substrate, and between the primer coat and the dispersion paint coat was tested by trying to remove the cloth strip. ~ood adhesion was found reyardless of whether it was peeled off dry or wetted by storing under water and re-drying. The same results were obtained from tests perfc~rmed according to Examples 1 to 6 with soft binder 2S films which had adjus-table monomer ratios, or with hard binder f1lms of polymers. Without exception, the cloth strips could be pulled off the dispersion paint coating leaving the lattice-type fabric structure embossed on the paintlayer;
29 however, no paint was taken off the substrate or the primer coat ~ . . . .
. . .
in this operation. The same resul-ts were obtained by cross-cutting the dried dispersion paint coating and trying to pull the disper-si.on paint film off the cross-cut squares by means of an adhesive tape. The paint layer did not come off either.
The following Examples illustrate the preparation of finely distributed dispersions of the invention.
E X A M P L E 1:
.. .. _ . . :
A stable monomer emulsion is prepared from styrene 134 parts by weight .
butylacrylate 200 parts by weight acrylamide .4.5 parts by weiyht methacrylic acid 12.0 parts by weight sodium salt of a secondary alkyl-sulfonate (C12-C16)10 parts by weight ..
reaction product of nonyl-phenol with 10 ~ 12 moles of ethylene oxide 5.0 parts by weight water 400 parts by weight The emulsion is metered i.nto a liquor of 230 parts by weight of water, 2 parts by weight of a non-ionic emulsifier and 8 parts ~ ~.
by weight of an ionic emulsifier. Simultaneously to the dosage of the emu~sion, a sol.ution of 2 parts by weight o~ ammonium persu~ate in 40 parts by weiyht o.E water is added.
The mean particle size of the dispersion adjusted to a pH
of 8 - 9 is 0.036 ~m.
E X A M P I. E 2:
Copolymer dispersions containing an optical brightener and having fine particles are obtained by dissolving additionally 0.1 part by weight of a vinyl-sulfonyl-pyrazoline brightener (cf.
29 German Offenleyungsschrift No. 2 011 552) in the rnonomer mixture - 15 ~
.. . . . . :: . : : : , . , . ~ .
~ -, ,,, -,, . , . :
HOE 7~F 317 of E~am~le 1, and subsec~uently preparing the plastics dispersions as before.
Both the aqueou~ plastics dispersion and the dry polymer film exhibit a chara~teristic blue fluorescence under UV radia-tion which allows detection of even very small polymer amounts in the different substrates. Fractionating by gel permeation chromatography shows that the optical brightener is incorporated uniformly in the polymer, i.e. no accumulations are formed in certain ranges of molecular weight. The a~Terage particle size of the copolymer dispersion containing the optical brightener is 0.038 ~m.
E X A M P L E 3:
A monomer mixture comprising styrene 170 parts by weight butylacrylate 170 parts by weight acrylamide 4 parts by weight methacrylic acid 10 parts by weight is metered into a liquor comprising 680 parts by weight of water, 25 parts by weight of a secondary sodium alkyl sulfonate (C12-C16) and 10 parts by weight of the reaction product of nonyl~phenol and from 8 - 12 moles of ethylene oxide.
A solution of 2 parts by weight of ammonium persulfate in 40 parts by weight of water is used as initlator. The average particle size diameter is 0.038 ~m.
E X A M P L E 4:
~ stable monomer emulsion is prepared from styrene 3600 parts by weight ~utyl acrylate 3600 parts by weight - 2g acrylam;`de 100 parts by weight ~ .
.
flOE 75/F 317 10~;80;~
methdcrylic ac.id 250 parts by ~eight sodium lauryl sulEate 340 parts by weight reaction product of nonyl~phenol with 8 - 12 moles of ethylene oxlde180 parts by weight water 10,000 parts by weight The emulsion is metered into a liquor of 5000 parts by weight of water, 80 parts by we;.ght of the non-ionic emulsifier and 280 parts by weight of the anionic emulsifier. A solution of 40 parts ~-by weight of ammonium persulfate in 900 parts by weight of water is metered in simultaneously. The average particle diameter of ~ . :
the dispersion adjusted to a pH of 8 - 9 is 0.042 ~m.
The dispersion can be concentrated in the same reaction vessel, under water jet vacuum, to a solids content of about 45 %.
The average particle size remains 0.042 ~m.
E X A M P L E 5: ;
A monomer mixture of methylmethacrylate 130 parts by weight butylacrylate . 200 parts by weight acrylic acid 12 parts by weight acrylamide 4 parts by weight is metered into a liquor of 660 parts by weight of water, 20 parts by we.ight of sodium lauryl ethoxylate-sulfate (with 2 - 5 moles of ethylene oxide) and 8 parts by wei.ght of a reaction product of nonyl-phenol and 6 - 10.moles of ethylene oxide. A solution of 3 parts by weight of potassium persulfate in 30 parts by weight of water is used as initiator. The average particle size is 0.04.1 ~m.
2~ Irhe composition of the liquor is as in Example 5.
. - 17 -: . . . .
- - . . . - :. .. . . .
: . .. , . - , . . . ~ .. ; -:
: ~ . - .. , : ~ .
IIOE` ~ 3 ~ 7 ~0~8~31 rhe m~ o~ r r~li xt~re comprises methylmethacrylat~100 parts by weight b~Itylacrylate230 parts by w~ight acrylic ac.i.d13 parts by weight ac~ylamic1e5 parts by wei.ght 2 parts by weight of potasslum persulfate dissolved in 20 parts ~y weight of water are employed as inltiator. The average par-ticle diameter is 0.045 ~m.
E X A M P ~. E 7 _ _ ~ _ _ A stable monomer emulsion is prepared from styrene 170 parts by weight butylacryla-te 170 parts by weight sodium lauryl sulfate15 parts by weight reaction product of nonyl-phenol with 8 - 12 moles of ethylene oxide5 parts by weight water 450 parts by weight The emulsion is metered into a liquor consisting of 200 parts by weight of wa-ter, 3 parts by weight of the non-ionic emulsifier and 8 parts by weiyht of the ioni.c emulsifier~ A
solution of 3 parts by weight of ammonium persulfate in 30 parts by weight of wat~r is simultaneously metered in.
The average parti.~le size of the dispersi.on being adjusted to ~I 8 - 9 is 0.060 ~m.
~ TqVE: EX~IPLE A: .
A copolymer dispersion is prepared comp~ising vinyl acetate 70 parts by weight Versatic(R)-~OC-acid vinyl ester 25 parts by weight srotonic acid 5 parts by wei.ght 29 with an anionic emulslfier and an inorganic per-compound and . .- . ~ . . :i,,,. .. . . ,, , ,; , . . . .
` 10~;8031 CO~ li.n~ L ta,~ 10 - 50 ~ o solids.
Tlle avera~Je particle size is 0.620 ~m.
COMPAR~ IVE EX MrÆE - :
A copolymer ~ispersion is prepared according to Æxample A~
consisting of vinyl acetate 70 parts by weight butylacrylate 30 parts by weight.
The average particle size is 0.270~m.
COMPARATlVÆ EXAMPLE C:
A copolymer dispersion is prepared, comprising styrene50 parts by weight butylacrylate 50 parts by weight acrylic acid2 parts by weight methacrylic acid 5 parts by weight acrylamide 3 parts by weight with a mixture of anionic and non-ionlc emulsifiers and an in-organic per-compound.
The average particle size is 0.150 ~m.
COMPARATIVE EXAMPLE D:
A copolymer composed of vinyl acetate 70 parts by weight maleic acid dibutylester 30 parts by weight is dissolved in ethyl acetate to yield a 60 % solution. The viscosity at 20 C acco~ding to H~ppler (DIN 53 015) is 80 P.
a primer having penetrative effect is prepared from this solution in the following manner:
60 % copolymer solution in ethyl acetate 28 parts by weight Shellsol A (trade mark) 62 parts by weight ~`~ ethyl~lycol acetate l0 parts by weight .
10~803~
?~ r \~" 1~ r,~
Froma copol~mer comprising vinyl toluene 85 parts by weight acrylic acid-2-ethy].-he~yl ester15 parts by weight 5 having a viscosity of about 60 cP at 20 C according to Hoppler in a 30 8 solution in xylene, a primer coating solution is pre-pared in the Eollowing manner:
copolymer 170 parts by weight white spirit 545 parts by weight Shellsol A (trade mark) 285 parts hy weight '-:
- 20 ~
' HOE 75~'F 317 10~8~
T ~ B ~, E
_ .,, Penetration test_in ~artz sand fill.i~s ~x- ~ver~e particle size (~Im) core weiyht (~) after appli-ample (according to light scatter- cation of 2 ml of a 17 %
.ng ~ethod) and 11 ~ dispersion 1 0.036 l2.3 13.6 2 0.038 11.8 12.5 3 0.038 12.1 12.8
4 0 04~ 10.5 11.9 0.041 11.3 11.9 6 0.045 11.1 11.5 7 0.060 10.5 11.Q
. _ . _ _ . _ __ . _ _ . _ _ . _ _ _ . _ _ _ . _ ~ _ _ . . _ _ _ , _ _ _ _ : _ .
Comparative Examples . . _ A 0.620 0.6 1.1 -~
B Ø270 3.4 3.8 C 0.150 6.0 6.4 D - 10.8 11.0 E - 10.4 11 2
. _ . _ _ . _ __ . _ _ . _ _ . _ _ _ . _ _ _ . _ ~ _ _ . . _ _ _ , _ _ _ _ : _ .
Comparative Examples . . _ A 0.620 0.6 1.1 -~
B Ø270 3.4 3.8 C 0.150 6.0 6.4 D - 10.8 11.0 E - 10.4 11 2
Claims
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the preparation of finely distributed plastics dis-persions particularly suitable for the solidifying primer coating of substrates to be painted, which comprises metering a monomer mixture containing (I) from 20 to 80% by weight of styrene and/or methyl meth-acrylate as hardening component provided that methyl methacrylate, if present in admixture with styrene, does not exceed 15% by weight of said mixture, (II) from 20 to 80% by weight of an acrylic acid ester with linear or branched alcohols having from 2 to 8 carbon atoms and/or a meth-acrylic acid ester with linear or branched alcohols having from 4 to 8 carbon atoms as plastifying component, (III) from 0.1 to 5% by weight of an amide of an .alpha.,.beta.-unsaturated carboxylic acid, and (IV) from 0.1 to 5% by weight of an .alpha.,.beta.-unsaturated monocar-boxylic acid, the total of components (III) and (IV) being in the range of from 0.2 to 8.5%
by weight, in the form of the pure monomer mixture or a preliminary emulsion, simultan-eously with an initiator, into an aqueous liquor containing an anionic emulsi-fier, said monomers being used in such an amount that the solids content of the final dispersion does not exceed 45% by weight, polymerizing said monomers in said aqueous liquor to form said dispersion, and adjusting said dispersion to a pH of 7 to 10.
by weight, in the form of the pure monomer mixture or a preliminary emulsion, simultan-eously with an initiator, into an aqueous liquor containing an anionic emulsi-fier, said monomers being used in such an amount that the solids content of the final dispersion does not exceed 45% by weight, polymerizing said monomers in said aqueous liquor to form said dispersion, and adjusting said dispersion to a pH of 7 to 10.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19752556327 DE2556327A1 (en) | 1975-12-13 | 1975-12-13 | FINE PARTICLE COPOLYMER DISPERSIONS AND THE PROCESS FOR THEIR PRODUCTION |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1068031A true CA1068031A (en) | 1979-12-11 |
Family
ID=5964380
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA267,591A Expired CA1068031A (en) | 1975-12-13 | 1976-12-10 | Finely distributed copolymer dispersion and their preparation |
Country Status (23)
| Country | Link |
|---|---|
| JP (1) | JPS5272795A (en) |
| AR (1) | AR216754A1 (en) |
| AT (1) | AT353480B (en) |
| AU (1) | AU504898B2 (en) |
| BE (1) | BE849342A (en) |
| BR (1) | BR7608151A (en) |
| CA (1) | CA1068031A (en) |
| CH (1) | CH627765A5 (en) |
| DE (1) | DE2556327A1 (en) |
| DK (1) | DK554976A (en) |
| ES (1) | ES454031A1 (en) |
| FI (1) | FI61491C (en) |
| FR (1) | FR2334729A1 (en) |
| GB (1) | GB1565529A (en) |
| IE (1) | IE43999B1 (en) |
| IT (1) | IT1070438B (en) |
| LU (1) | LU76368A1 (en) |
| MX (1) | MX143459A (en) |
| NL (1) | NL7613642A (en) |
| NO (1) | NO764203L (en) |
| PT (1) | PT65953B (en) |
| SE (1) | SE422803B (en) |
| ZA (1) | ZA767362B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3128025A1 (en) * | 1981-07-16 | 1983-02-03 | Hoechst Ag, 6000 Frankfurt | METHOD FOR PRODUCING AQUEOUS COPOLYMERISAT DISPERSIONS AND USE OF THE DISPERSIONS |
| US4423199A (en) * | 1982-09-30 | 1983-12-27 | Rohm And Haas Company | Acrylamide containing emulsion copolymers for thickening purposes |
| DE3344354A1 (en) * | 1983-12-08 | 1985-06-13 | Basf Ag, 6700 Ludwigshafen | METHOD FOR PRODUCING AQUEOUS POLYACRYLATE-COPOLYMER DISPERSIONS AND THEIR USE IN THE MAKING OF LEATHER |
| DE3724858A1 (en) * | 1987-07-28 | 1989-02-09 | Texaco Ag | WAESSED PLASTIC DISPERSION |
| US5202375A (en) * | 1989-07-28 | 1993-04-13 | Rohm And Haas Company | Water-resistant polymeric emulsions |
| CA2064081A1 (en) * | 1989-07-28 | 1991-01-29 | Rohm And Haas Company | Water-resistant polymeric emulsions |
| FR2691969B1 (en) † | 1992-06-04 | 1994-09-23 | Prolabo Sa | Nanoparticles of functionalized polymers, their preparation process and their use. |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3242121A (en) * | 1961-05-17 | 1966-03-22 | Union Carbide Corp | Method of preparing latex binder of styrene, an alkyl acrylate, and an ethylenically unsaturated carboxylic acid |
-
1975
- 1975-12-13 DE DE19752556327 patent/DE2556327A1/en not_active Ceased
-
1976
- 1976-12-06 BR BR7608151A patent/BR7608151A/en unknown
- 1976-12-07 ES ES454031A patent/ES454031A1/en not_active Expired
- 1976-12-08 NL NL7613642A patent/NL7613642A/en active Search and Examination
- 1976-12-09 CH CH1550776A patent/CH627765A5/en not_active IP Right Cessation
- 1976-12-10 AU AU20474/76A patent/AU504898B2/en not_active Expired
- 1976-12-10 IE IE2705/76A patent/IE43999B1/en not_active IP Right Cessation
- 1976-12-10 DK DK554976A patent/DK554976A/en not_active Application Discontinuation
- 1976-12-10 PT PT65953A patent/PT65953B/en unknown
- 1976-12-10 AT AT912776A patent/AT353480B/en active
- 1976-12-10 NO NO764203A patent/NO764203L/no unknown
- 1976-12-10 ZA ZA767362A patent/ZA767362B/en unknown
- 1976-12-10 CA CA267,591A patent/CA1068031A/en not_active Expired
- 1976-12-10 FI FI763556A patent/FI61491C/en not_active IP Right Cessation
- 1976-12-10 SE SE7613949A patent/SE422803B/en not_active IP Right Cessation
- 1976-12-10 IT IT30319/76A patent/IT1070438B/en active
- 1976-12-10 AR AR265789A patent/AR216754A1/en active
- 1976-12-10 LU LU76368A patent/LU76368A1/xx unknown
- 1976-12-11 JP JP51148330A patent/JPS5272795A/en active Granted
- 1976-12-13 FR FR7637468A patent/FR2334729A1/en active Granted
- 1976-12-13 BE BE173202A patent/BE849342A/en not_active IP Right Cessation
- 1976-12-13 MX MX167385A patent/MX143459A/en unknown
- 1976-12-13 GB GB51970/76A patent/GB1565529A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FI61491C (en) | 1982-08-10 |
| NO764203L (en) | 1977-06-14 |
| IT1070438B (en) | 1985-03-29 |
| AR216754A1 (en) | 1980-01-31 |
| JPS5272795A (en) | 1977-06-17 |
| CH627765A5 (en) | 1982-01-29 |
| IE43999L (en) | 1977-06-13 |
| SE422803B (en) | 1982-03-29 |
| IE43999B1 (en) | 1981-07-15 |
| AU504898B2 (en) | 1979-11-01 |
| PT65953A (en) | 1977-01-01 |
| ZA767362B (en) | 1977-11-30 |
| AT353480B (en) | 1979-11-12 |
| FI61491B (en) | 1982-04-30 |
| FI763556A (en) | 1977-06-14 |
| LU76368A1 (en) | 1977-06-28 |
| ATA912776A (en) | 1979-04-15 |
| GB1565529A (en) | 1980-04-23 |
| PT65953B (en) | 1978-07-05 |
| DE2556327A1 (en) | 1977-06-23 |
| NL7613642A (en) | 1977-06-15 |
| AU2047476A (en) | 1978-06-15 |
| BR7608151A (en) | 1977-11-22 |
| DK554976A (en) | 1977-06-14 |
| FR2334729B1 (en) | 1982-08-13 |
| ES454031A1 (en) | 1978-03-01 |
| FR2334729A1 (en) | 1977-07-08 |
| BE849342A (en) | 1977-06-13 |
| SE7613949L (en) | 1977-06-14 |
| JPS6159322B2 (en) | 1986-12-16 |
| MX143459A (en) | 1981-05-13 |
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