DE1911360C3 - Stabilized, self-crosslinkable polymers - Google Patents

Description

NH ₂

in which R = - H, -CH _3, -C ₂ H ₅ or -C ₄ H _9, contains the individually or has been added in the mixture during or after the polymerization as a free acid or soluble salts thereof

2. Stabilized polymer according to claim 1, characterized in that it is in solution or Dispersion is present, the N-hydroxy-alkylated polymerized as a crosslinking component Acrylamides and / or N-hydroxyalkylated methacrylamides the general formula

O H

C = C-C-N-R ₂
HR ₁

contain, where R _{1 is} hydrogen or CH ₃ radical and R _{2 is} CH ₂ OH radical, or polymerized N-hydroxyalkylated mono- and / or diamides of β, / ί-unsaturated dicarboxylic acids of the general formula

OHHOH

Il I I Il I

HO - C - C = CC - N - R ₂
or

HIGH HIGH

I Il I I Il I

R ₂ -N - C - C = CC - N - R ₂

where R ₂ = CH ₂ OH.

3. Stabilized polymer according to claim 1 and 2, characterized in that the to be stabilized, crosslinkable copolymers 0.25 to 50 percent by weight of an N-methylolamide «, / ^ - unsaturated monocarboxylic acid and / or one Di-N-methylolamids of an α, / i-unsaturated Dicarboxylic acid and 99.75 to 50 percent by weight of at least one other olefinically unsaturated, polymerizable compound included in copolymerized form.

It is known that crosslinkable polymers can be produced by polymerization at certain pH values and at Produce low temperatures by adding acrylic or methacrylic acid amides, in which the amide groups by reactive groups such as methylol, methylol alkyl ether or terL-aminomethylene groups are substituted, polymerized under such conditions, that one is soluble in organic solvents polymers with film-forming properties obtained in which the monomers mentioned have been polymerized without splitting off the reactive group are.

ίο The reactive groups, namely MethyH-, Methylolalkyläther- or tert-aminomethyl taps of acrylamide or methacrylamido esters of these polymers can under the action of heat and / or split by acidic catalysts

the polymers are converted into crosslinked, insoluble products. These polymers however, do not meet all practical requirements in some areas of application, as copolymers with free methylol groups when standing for a long time

Slowly cross-link room temperature and thus become unusable.

Polymers with methylol ether groups do not show this phenomenon, but their crosslinking temperatures are lower too high for some purposes.

In general, the known polymers of this type are used in the presence of acids and / or acid donors crosslinked, since under these conditions the crosslinking is faster and at lower temperatures takes place than when applying heat alone.

However, it is desirable for certain purposes. Use polymers that are just as quick without the addition of acids and / or acid donors and easily crosslink like the known products in the presence of these catalysts.

In the German Auslegeschrift 1 212 729 is already a process for the production of self-crosslinkable polymers by homopolymerization or copolymerization of olefinically unsaturated substituted methylol acid amides, given

if as a mixture with other olefinically unsaturated monomers, in aqueous emulsion at pH values between 3 and 9 and temperatures of not more than 80 ° C in the presence of catalysts, which is characterized in that the olefinically unsaturated substituted methylol group-bearing amides N -Methylolamides.! - used olefinically unsaturated carboxylic acids, the methylol groups of which are acrylated.
It is the object of the present invention. the

thermal stability of self-crosslinkable polymers, the N-hydroxyalkylated amide of a n.,; - unsaturated Containing mono- or dicarboxylic acid polymerized, in their solutions, preferably in their aqueous dispersions, so without improving

to introduce a protective group and without a

Discoloration of the stabilized solution or dispersion

occurs sooner or later and without this reducing the reactivity of the reactive groups.

This task is solved by using the

Adds a specifically acting stabilizer to solutions or dispersions.

The present invention relates to stabilized, self-crosslinkable polymers, consisting of a Homopolymer or copolymer made from olefinically unsaturated amides containing methylol groups «, / ^ - obtained from unsaturated mono- or dicarboxylic acids has been, and a stabilizer, characterized in that it is ais stabilizer, based on the

I 91 1 360

polymer, 0.1 to 1 percent by weight of a «-aminotarboxylic acid the general formula

HO

I! I

R - C - C - OH

NH ₂

Kt which R = - H, -CH ₃ , -C ₂ H ₅ or -C ₄ H ₉ , which has been added individually or in a mixture during or each of the polymerization as free acid or its soluble salts.

A particular embodiment of the invention is characterized in that the stabilized polymer is present in solution or dispersion, the N-hydroxy-alkylated polymerized in as the "crosslinking component" Acrylamides and / or N-hydroxyalcylated Msthacrylamide of the general formula

H OH

I I! I.

C = CC - N - R ₂
HR ₁

contain, where R, hydrogen or CH ₃ radical and Rj is CH ₂ OH radical, or polymerized N-hydroxyalkylated mono- and / or diamides of «^ -unsaturated dicarboxylic acids of the general formula

OHHOH

Il I I Il I

HO - C - C = CC - N - R ₂
or

HIGH HIGH

I Il I I I! I.

R ₂ -NCC = CCNR ₂

where R ₂ = CH ₂ OH.

A further specific embodiment of the invention is characterized in that the to be stabilized, crosslinkable copolymers 0.25 to $ 0 weight percent of an N-Methylolamids a "/ f-unsaturated monocarboxylic acid and or a di-N-methylolamids an n ,," unsaturated Dicarboxylic acid and 99.75 to 50 percent by weight of at least one other olefinically unsaturated, polymerizable compound in copolymerized form.

The preferred π-aminocarboxylic acid is α-aminoacetic acid or their alkali, ammonium or amine salts.

Preferred monomers which are present in polymerized form in the polymers and their stabilization is particularly pronounced are N-methylolacrylamide and / or N-methylol methacrylamide.

The preferred embodiment of the invention comprises those polymers which are in the aqueous phase.

The stabilizer is added to the solution or dispersion to be treated in solid or dissolved form. The addition in solid form is preferred, the addition of the free aminocarboxylic acids is preferred Embodiment. However, the use of amine salts can be very useful because these are more soluble in many organic media.

In the preferred embodiment of the invention, those homopolymers or copolymers of amides containing N-methylol groups and olsfinically α, / ί-unsaturated mono- or dicarboxylic acids which have been prepared by copolymerization in an aqueous emulsion are stabilized.
The copolymers contain

I. 0.25 to 50 percent by weight of an N-methylolamide an α, / i-unsaturated mono- or dicarboxylic acid and

^ "^ '^ ^ is 50 weight percent at least one other olefinically unsaturated polymerizable compound.

The monomers can, in order to obtain the stabilized, self-crosslinkable polymers, for themselves

or polymerized as a mixture with one another in an aqueous emulsion. The monomers are preferred but used for the production of copolymers with other olefinically unsaturated monomers, wherein the first-mentioned monomers in amounts of about 0.25 to 50, preferably 0.5 to Percent by weight are used.

Suitable olefinically unsaturated monomers which are used as compound polymerization components can are for example

a) «, / i-olefinically unsaturated monocarboxylic acids and their derivatives, such as acrylic and methacrylic acid amides. Acrylic and methacrylonitrile, esters of acrylic and methacrylic acid, especially those with saturated monovalent aliphatic

Alcohols with 1 to 20 carbon atoms, such as esters of the acids mentioned with methyl, ethyl, Propyl, isopropyl, isobutyl, hexyl, octyl, stearyl alcohol, cyclohexanol, methylcyclohexanol, also with benzyl alcohol, phenol, cresol, furfuryl alcohol; α, / i-olefinically unsaturated dicarboxylic acids and their derivatives, such as fumaric acid and maleic acid, mono- or diamides, fumaric acid and maleic acid mono- or dinitrile. Mono- or diesters of fumaric acid or maleic acid, especially those with saturated ones monohydric aliphatic or cycloaliphatic alcohols having 1 to 20 carbon atoms, such as Esters of the acids mentioned with methyl, ethyl, propyl, isopropyl, isobutyl, hexyl, octyl, Stearyl alcohol, cyclohexanol, methylcyclohexanol, also with benzyl alcohol, phenol, cresol. Furfuryl alcohol;

b) aromatic monovinyl compounds such as styrene, a-methylstyrene, vinyltoluene, p-chlorostyrene or other ring-substituted vinylbenzenes;

c) esters of vinyl alcohols with carboxylic acids or with hydrohalic acids, vinyl ethers, vinyl ketones, such as vinyl chloride, vinylidene chloride, vinyl isobutyl ether;

d) conjugated diolefins with 4 to 6 carbon atoms, like butadiene. Isoprene, 2,3-dimethylbutadiene. Chloroprene.

In addition, other mono-olefinically unsaturated monomers can be used as copolymerization components, such as maleic acid, fumaric acid or crotonic acid esters, styrene sulfonic acid, unsaturated aliphatic or cycloaliphatic hydrocarbons. Furthermore, crosslinking monomers with several non-conjugated olefinic unsaturated groups in amounts of about 0.01 to 5, preferably 0.01 to 3 percent by weight, based on the weight of the total monomers,

are used, such as glycol diacrylate, glycol dimethacrylate, Acrylic acid and / or allyl methacrylate, divinylbenzene, triacrylol-perhydro-s-triazine, triallyl cyanurate or substitution products of the compounds mentioned.

It can be copolymers of two as well as a higher number of monomers, the belong to different classes of compounds. These monomers are selected depending on the desired properties of the copolymers.

Copolymers containing one or more "reinforcing" monomers are of particular interest (i.e. monomers whose polymerisation increases the hardness of the copolymers) and contain at least one "elasticizing" monomer in copolymerized form. Acting as "elasticizing" Monomers can be conjugated diolefins, esters of acrylic acid with more than 2 carbon atoms in the ester group and esters of methacrylic acid with more than 4 carbon atoms in the ester group be used. The proportion of the "elasticizing" monomers in the total amount of the monomers is preferably 40 to 90 percent by weight. Suitable "reinforcing" monomers are for example styrene, substituted styrenes, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, Esters of acrylic or methacrylic acid with lower alcohols. These monomers become useful used in an amount of 1 to 40 percent by weight, based on total monomers.

The monomers containing carboxyl groups, such as acrylic and methacrylic acid, are used in the copolymers generally polymerized in relatively small amounts, unless copolymers are used with strongly hydrophilic properties should graze. For the production of copolymers, obtained by polymerizing the monomers in aqueous emulsion the said olefinically unsaturated acids preferably in amounts of 0.1 to 10 percent by weight, calculated on the weight of total monomers used. The amides of the acids mentioned are also used preferably used in the aforementioned amounts.

Aqueous copolymer dispersions are obtained when the abovementioned monomers in aqueous Dispersion using emulsifiers in a manner known per se at pH values copolymerize between 3 and 9. Both cationic, anionic and nonionic emulsifiers and combinations of these can be used here Emulsifiers are used.

Examples of suitable anionic emulsifiers are higher fatty acids, resin acids, acidic fatty alcohol sulfuric acid esters, higher alkyl sulfonates and alkylarylsulfonates, sulfonated castor oil, higher oxyalkyl sulfonates, Sulfosuccinic acid esters, salts of fatty acid condensation products with oxyalkylcarboxylic acids, Aminoalkylcarboxylic acids, the water-soluble salts of sulfonated ethylene oxide adducts.

Examples of cationic emulsifiers are: salts of alkylamines, aryl, alkylaryl or resin amines and inorganic acids and salts of quaternary ammonium compounds.

The reaction products of ethylene oxide, known per se, with long-chain fatty alcohols, such as cetyl, lauric, oleyl, octadecyl alcohol or phenols, such as octyl, dodecylphenol, are suitable as emulsifiers of a nonionic character, in particular conversion products of more than 10 mol, preferably 15 ~ up to 30 moles of ethylene oxide with 1 mole of alcohol or phenol are used.
The total amount of the abovementioned emulsifiers can be between 0.5 and 20%, calculated on the total amount of monomers. It is preferably between 2 and 10%.
According to a particular embodiment of the invention, exclusively nonionic emulsifiers or mixtures of these emulsifiers with up to 0.5% of cationic and / or anionic emulsifiers, based on the polymer, are used. In this way, latices of particularly high stability are obtained. If the polymer simultaneously contains - COOH, - CONH ₂ , -SO ₃ H or other hydrophilic groups, the latexes show a high level of reemulsifiability The film can still be redispersed smoothly with water for a certain time.

The polymerization is preferably carried out at temperatures of about 10 to 50 ^° C., however

Temperatures up to about 80 ^° C. can also be used.

The pH value to be maintained during the production of the copolymers can vary between 3 and 9, expediently between pH 4 and 9, in the case of the production of reemulsifiable latexes the Maintaining a pH value between 4 and 6 is proven. When the polymerization is complete, the latexes are generally adjusted to pH values of about 6.5 to 9, which increases the stability of the products will. Compounds that regulate the molecular weight, such as long-chain alkyl mercaptans, diisopropyl xanthate among others, can be used in the polymerization can also be used.

Inorganic per compounds such as potassium or ammo

nium persulfate, hydrogen peroxide, percarbonates, organic Peroxide compounds such as acyl peroxides, for example benzoyl peroxide, alkyl hydroperoxides such as fert.-butyl hydroperoxide, cumene hydroperoxide, p-menthane hydroperoxide, dialkyl peroxides such as di-tert-butyl peroxide, into consideration. The inorganic or organic per compounds are advantageously used used in combination with reducing agents in a manner known per se. Suitable reducing agents are for example sodium pyrosulfite or bisulfite, sodium formaldehyde sulfoxylate, triethanolamine.

The amount of catalyst to be considered is within that which is customary for the polymerization of this Type of borders in question, d. H. between

0.01 and 5%, calculated on the total monomers used.

The effect of the stabilizer used is surprising, since the solutions treated according to the invention or dispersions, which are to be stabilized

Contain polymers, remain stable at around 30 ° C and 100 days, while non-stabilized - otherwise The same polymers containing - solutions or dispersions spontaneously crosslink after 32 days, what is clearly shown in an increase in viscosity.

example 1

In a reaction vessel equipped with a stirrer, thermometer, two addition vessels, protective gas inlet

pillare and a reflux condenser are provided, 2 parts of sodium dodecyl sulfate and 2 parts of a reaction product dissolved from p-alkylphenol and 13 to 15Mol ethylene oxide, the p-position Alkyl radical contains 6 to 15 carbon atoms.

To this 100 ml of an emulsion are added, which was prepared from 500 parts of deionized water, 274 parts of butyl acrylate, 12 parts of acrylamide, 172 parts of styrene, 13 parts of sodium dodecyl sulfate and

13 parts of a reaction product of p-alkylphenol (as already described) and 13 to 15MoI Ethylene oxide.

In addition, 2.5 ml of a solution of 15 parts of N-methylolacrylamide in 25 parts of deionized water are added. After the temperature has been increased to 40 ^° C., 2 parts each of a solution of 2 parts of potassium peroxydisulfate in 30 parts of water and 2 parts of sodium pyrosulfate in 30 parts of water are added in succession.

As soon as the polymerization has started, the bulk of the pre-emulsion, N-methylolacrylamide solution and potassium persulfate or sodium bisulfite solution were added dropwise within 2 hours.

with a solids content of about 41%. A part of this dispersion is according to the invention Process stabilized by adding 150 mg of aminoacetic acid per 100 g of solid polymer.

One sample each of the stabilized and the unstabilized dispersion were at elevated temperatures stored.

The unstabilized sample crosslinked at 40 ° C

14 days, while the stabilized sample showed an unchanged viscosity after 120 days.

Example 2

Work as in Example 1. Only N-methylol methacrylamide is used instead of N-methylolacrylamide used. The storage stability of the unstabilized dispersion is 20 days compared to 120 days the stabilized dispersion, each at 40 ° C.

Example 3

In a reaction vessel with a stirrer, two Monomer feed vessels, thermometer and protective gas inlet capillary are fitted in . 500 g of demineralized water 10 g of a reaction product of p-alkylphenol (with 6 to 15 carbon atoms in Alkyl radical) and 20 to 30 mol of ethylene oxide, 5 g of sodium dodecyl sulfate and 10 g of sodium dioctyl sulfosuccinate as above solved. The air is then displaced from the apparatus with nitrogen and then 10% of the monomer mixture A. which was made from 400 g of Athyiacrylat and 77 g of acrylonitrile and 10% of the Monomer solution B, a solution of 23 g of N-methylolacrylamide in 100 g of deionized water was added. After the temperature has been increased to 40 ° C., 15% of a solution of 0.5 g of potassium peroxydisulfate is added in 30 g of deionized water and 15% of a solution of 0.2 g of sodium pyrosulfite in 30 g of deionized Water added. After the start of the polymerization, the remaining Quantities of solutions A and B. such as the potassium peroxydisulfate solution and the sodium bisulfite solution admitted. * 5

Ice dispersion is obtained which has a solid content of about 42%. The dispersion is divided and one part as indicated with ISO mg Aminoacetic acid stabilized on 100 g of polymer. This part has a much improved thermal Stability with respect to the dispersion not treated according to the invention.

Example 4

The procedure is as indicated in Example 3, but the monomer solution B is prepared from 100 g of deionized Water in which 23 g of N-methylolacrylamide and 0.75 mg of aminoacetic acid are dissolved. The received Dispersion with a solids content of about 42% shows compared to that according to Example 3 without the addition a significantly improved thermal stability obtained from aminoacetic acid.

Example 5

In a reaction vessel with a stirrer, thermometer, protective gas inlet capillary and two monomer feed vessels is equipped, 5 g of sodium dioctyl sulfosuccinate, 3.5 g of Na-tetrapropylene benzene sulfonate and 20 g of a reaction product of p-alkylphenol (with 6 to 15 carbon atoms in the Alkyl chain) with 15 to 20 mol ethylene oxide in 300 g dissolved in deionized water. The pH value is adjusted to about 5 and then the air in the reaction space is displaced with nitrogen. It will be 10% of the Monomer mixture A consisting of 300 g of vinyl acetate, 175 g of butyl acrylate and 10 g of a reaction product from p-alkylphenol and 15 to 20Mol ethylene oxide (see above) was prepared, and 10% of a solution B of 20 g of N-methylolacrylamide in 150 g of deionized water were added. After brief stirring, 40% a solution of 2.5 g of ammonium peroxydisulfate in 130 g of deionized water and 40% of a solution of 3 g of sodium pyrosulfite in 130 g of deionized water were added. Once the polymerization has started, the remaining solutions A and B, such as that of potassium peroxydisulfal, become in a period of 2 hours and sodium bisulfite added.

The pH of the dispersion, which has a solids content of approx. 42% is adjusted to 5 to 6 _{with NH 4 OH.}

The dispersion is divided and one part in the specified manner with 150 mg of aminoacetic acid each 103 g of polymer stabilized.

Example 6

The procedure described in Example 5 is followed. However, the monomer solution B is prepared as follows:

20 g of N-methylolacrylamide and 0.75 mg of aminoacetic acid are dissolved in 150 g of deionized water. It a dispersion is obtained which contains about 42% solids and compared to that of Example 5 without the Addition of aminoacetic acid has a significantly improved thermal stability.

Example 7

In a reaction vessel as in Example 3 give, 3 g of sodium dodecyl sulfate are dissolved in 600] deionized water and the pH de Solution set to 4 The air is displaced from the reaction vessel by flushing with nitrogen after which 10% of the mono exercise A. manufactured from 340 g of ethyl acrylate, 110 g of acrylonitrile, 12 g of one Reaction product of p-alkylphenol (6 to 15 carbon atoms in the alkyl chain) with 10 mol of ethylene oxide and 12 g of a p-Aüylpbenols rna 30Mc Athyknoxyd, whereby the Alkyipbeaol 6 to 15 C-atom

509619 / M

in the alkyl group, and 10% of a monomer solution B, consisting of 50 g of di-N-methylol fumaramide and add 100 grams of deionized water.

Then 2.0 g of ammonium peroxydisulfate, dissolved in 20 ml of deionized water, as well 2.0 g of sodium pyrosulfite in 25.0 g of deionized water were added to the reaction mixture. Once the polymerization begins, the remaining amounts of the monomer mixtures A and B, next to it at the same time the solutions of 2.5 g of ammonium peroxydisulfate in 50 g of deionized water and 2.5 g of sodium pyrosulfite dissolved in 50 g of deionized water was added dropwise over the course of 2 hours. The reaction temperature must be kept at 45 ° C during this time. A dispersion is obtained with a solids content of about 39%. The dispersion is divided and a part according to the method according to the invention by adding 150 mg of aminoacetic acid per 100 g of polymer stabilized.

Example 8

The procedure given in Example 7 is followed. The monomer solution B, however, consists of 50 g of di-N-methylol fumaramide, 0.75 g of aminoacetic acid and 100 g of water. It becomes a dispersion, its solids content 39%, obtained with improved thermal stability.

The polymers and copolymers stabilized according to the invention have free methylolamide groups which ^{are condensed at elevated temperatures between 20 and 150 °} C. and / or under the action of acidic catalysts with elimination of water, with the formation of insoluble crosslinking products. Because of these properties, it turns into insoluble products even under mild conditions. The polymers and copolymers stabilized according to the invention can therefore be used for the production of structures of any shape, such as coatings, impregnations and bonds. It is surprising that the stabilization carried out according to the invention does not adversely affect the catalytically triggered crosslinking when these polymers and / or copolymers are used.

Example 9

In a reaction vessel as indicated in Example 1, a solution of 1.4 parts of a 35% strength aqueous solution of a potassium polymethacrylate. which has a viscosity of 1500 to 2500 cP, in 250 parts of deionized water dissolved. This water phase is after the addition of 0.5 parts of a 1% Iron trichloride solution and 0.25 part of a 1% strength 250 parts of vinyl acetate, 225 parts of butyl acrylate, 15 parts of a condensation product of p-nonylphenol with 30 moles of ethylene oxide and 15 parts of a condensation product from p-nonylphenol with 10 mol

Ethylene oxide, and also 10% of 175 parts of an aqueous solution containing 25 parts of N-hydroxymethylacrylamide and 2 parts of sodium diisotridecylsulfosuccinate, emulsified. Then, in succession, 10% of a solution of 3 parts of ammonium peroxydisulfate in 97 parts of water and 10% of a 1.5% strength aqueous Rongalit solution, which makes up 100 parts, are added. Within 2 to 3 minutes, the temperature begins to rise due to the onset of polymerization. By cooling is to take care that the temperature does not exceed 5O ⁰ C. As soon as this initial reaction begins to subside, the remaining solutions are fed into the reaction vessel in parallel within 3 hours. Thereafter, the reaction mixture is maintained for 30 minutes at the reaction temperature of 5O ⁰ C, then cooled and adjusted with dilute ammonia solution to a pH value of about. 6 The dispersion obtained is divided and one part stabilized according to Example 1, which is stored at 50 ° C. for 4 weeks

can without changing the structure of the sample.

Example 10

The procedure given in Example 9 is followed. However, already stabilized N-hydroxymethylene acrylamide is used for the polymerization related. With this method, the same stabilizing effect against thermal influences is achieved.

The table below gives an overview of the storage stabilities of those mentioned in the examples Polymer dispersions:

Cobalt chloride solution adjusted with formic acids to a pH value of 4.5 to 4.0. Then will the reaction vessel is freed from atmospheric oxygen by purging with nitrogen. In this then heated to 30 ° C Solution will be 10% of a mixture

40

45

example .storage temperature in C 1 40 2 40 3 50 4th 50 5 20th 50 6th 50 7th 50 8th 20th 50 9 50 10 50

Storage stability

without

stabilizer
networked after

14 days
20 days
20 hours
20 hours
14 days
6 hours
6 hours
!Day
14 days
!Day
2 days
!Day

with stabilization

unchanged

after

120 days

120 days

7 days

6 days

3 months

7 days
7 days

14 days
3 months

14 days
1 month 3 weeks

As explained in the examples, the situation was i Stability of the sample mixed with aminoacetic acid always with the same polymer as no Arnim acetic acid was added, compared.

Claims (1)

Patent claims: 1. Stabilized, self-crosslinkable polymers, consisting of a homo- or mixed polymer, that from olefinically unsaturated, methylol group-bearing amides α, / f-unsaturated Mono- or dicarboxylic acids has been obtained and a stabilizer, characterized in that that it is used as a stabilizer, based on the polymer, 0.1 to 1 percent by weight of a α-aminocarboxylic acid of the general formula HO I Il R — C — C — OH