DE2124525C3 - Process for the production of microcapsules - Google Patents

Description

a) residues of at least 4 carbon atoms containing monohydroxy compounds and
bj) residues of an amine containing hydroxyl groups or

b,) residues of a polyethylene glycol or

b ₃ ) residues of an alcohol containing at least two hydroxyl groups and residues of Me — O ₃ S groups bonded to carbon atoms, where Me denotes an alkali metal atom or
b ₄ ) residues of aliphatic hydroxycarboxylic acids which are bonded to the aminoplast precondensate with the hydroxyl group, and optionally an amine containing hydroxyl groups,
contain.

Addition products are among the aminoplast precondensates from which these reactive surfactants are derived understood from formaldehyde to methylolierhare nitrogen compounds. As so-called Aminoplast formers are mentioned here:

1,3,5-aminotriazines such as N-substituted melamines, e.g. B. N-butylmelamine, N-trihalomethylmelamine, and ammeline, guanamines, e.g. B. benzoguanamine, acetoguanamine or diguanamine. Also suitable are alkyl or aryl ureas and thioureas, alkylene ureas or diureas, e.g. B. ethylene urea, propylene urea, acetylenediurea or 4,5-dihydroxyimidazolidone-2 and derivatives thereof, e.g. B. 4,5-DihydroxyimidazoIidon-2 substituted in the 4-position on the hydroxyl group by the radical -CH ₂ CH ₂ CO-NH-Ch _{2 -OH.} The methylol compounds of urea and melamine were preferably used. In general, particularly valuable products give products that are as highly methylolated as possible. Both the predominantly monomolecular and highly precondensed compounds are suitable as starting materials. The aminoplast precondensates used as starting materials for the production of the reactive surfactants can also be present as ethers of alkanols with 1 to 3 carbon atoms, in particular as methyl ethers.

Accordingly, highly surface-active etherified methylolmelamines odci are preferred as reactive surfactants Methylolureas used.

There is a large number of reactive surfactants which are suitable for the process according to the invention nonionic, anionic and cationic surfactants.

Particularly suitable non-ionic reactive surfactants are, for. B. containing curable etherified methylol groups Aminoplast precondensates, the methylol groups of which are partly with hydroxy compounds of the formula

HO- (CH ₂ -CH ₂ -OJ ₁₁ -H

55

60

where η is an integer from 2 to 115, and is partially etherified with a monoalcohol containing 4 to 7 carbon atoms.

Compounds of the formula (1) are preferably polyethylene glycols. The monoalcohols are it is z. B. amyl alcohols, hexanol (l), 2-ethylbutanol (l), dodecanol, benzyl alcohol, stearyl alcohol or especially n-butanol.

Of particular interest as reactive surfactants are curable ethers of methylolureas or methylolmelamines, their methylol groups partially with a polyethylene glycol of average molecular weight 1000 to 5000 and are partially etherified with an alkanol with 4 to 7 carbon atoms. Reactive surfactants of this type are described in French patent 13 81 811.

As reactive surfactants with an anionic character, z. B. aminoplast precondensates containing etherified methylol groups, the methylol groups of which have been reacted partly with monohydroxy compounds containing at least 4 carbon atoms and partly with alcohols containing at least two hydroxyl groups, and which contain Me-O ₃ S groups bonded to carbon atoms, where Me is an alkali metal atom. Particularly suitable surfactants of this type are above all etherified methylolureas or methylolmelamines, the methylol groups of which are partly with alkanols containing 4 to 18 carbon atoms, and partly with alcohols of the formula H- (O-CH ₂ -CH ₂ ) ^ - OH, where Ot is a represents an integer of at most 25, are etherified and contain soft Me — O ₃ S groups bonded to carbon atoms, where Me denotes an alkali metal atom. Such anionic reactive surfactants are described in the French patent

14 70 103.

Other interesting reactive surfactants with an anionic character are e.g. B. containing etherified methylol groups Aminoplast precondensates, the methylol groups of which are partially with monohydroxy compounds, which contain 4 to 22 carbon atoms, partly with aliphatic hydroxycarboxylic acids which 2 to Have 4 carbon atoms and optionally partially with an alkanolamine containing 2 to 6 carbon atoms has, are etherified. These reactive surfactants include, in particular, etherified methylolureas or methylolmelamines, some of which methylol groups with alkanols, which Contain 4 to 22 carbon atoms, some with saturated hydroxyalkanecarboxylic acids which have 2 to 4 carbon atoms, and optionally partly with ethanol, diethanolamine or triethanolamine are etherified. Such anionic reactive surfactants are described in the French patent

15 81 989 Ix push.

Aminoplast precondensates are preferably used as so-called cationic reactive surfactants Tvleiyioigruppen partially with an alkanol or a fatty acid, each containing at least 4 carbon atoms and partly with an alkanolamine, which has 2 to 6 carbon atoms are reacted. Particularly suitable representatives of these surfactants Kind are Methylolmelamine, whose methylolgruppen partly with an alkanol, which 4 to 22 carbon atoms and are partially etherified with ethanol, diethanol or triethanolamine. Cationic Reactive surfactants of this type are described in French patent 10 65 686.

The same can be used for the production of the aminoplast precondensals with low surface activity Aminoplast formers are assumed, as they are specified for the reactive surfactants. Is preferred meanwhile, as an aminoplast precondensate of low surface activity, an unetherified one or with at most 3 carbon-atom containing alcohols etherified methylolmelamine and / or a corresponding one Methylolurea used. Di- to hexamethylolmelamines are of particular interest. In contrast to the reactive surfactants, the aminoplast precondensates result in low surface activity after mixing and shaking together with a solvent practically none stable Foams. As a rule, such aminoplate precondensates in dilute solution influence the upper

5 \ 6

| ί surface tension of the solvent also only un- ammonium salts of strong acids, such as ammonium

H essential. chloride, nitrate, sulfate or dihydrogen phosphate. It G

| j The preparation of such AminoplEstvorkondcn- come oxidants that formaldehyde to J ₁

fi sate is known and takes place, provided that formic acid is able to oxidize in aqueous me, such as hydrogen P

jg medium is being worked, z. B. by having 1 mole of 5 superoxide into consideration. The use of acids _s

However, urea or melamine in as much of an aqueous one has proven to be the most appropriate. _s

About 37% formaldehyde solution dissolves that on As already mentioned, water is preferably used as]

1 mole of urea about 1.2 to 2 moles, used per 1 mole of distribution agent, where one j

Melamine accounts for about 3 to 6 moles of formaldehyde. encapsulating material one insoluble in water and;

If necessary, the resulting solutions are used with a substance that does not react with water. Surrounding

R slightly diluted with water and reversing at a pH value, however, it is quite possible that the following:

g, over 8.0 and slightly elevated temperature for some time parting medium with water immiscible, organic

precondensed. The amino solvents obtained in this way and as the material to be encapsulated were

plastic pre-condensate solutions are added to the already pre-soluble substances or aqueous solutions thereof

ΐ- formed primary capsule suspensions, whereupon 15 turns.

Care should be taken to ensure that the dispersity of the suspension is an example of such distribution means

preserved. Each individual capsule must have freely moving aliphatic and aromatic hydrocarbons and

be borrowed, which by adding a sufficient amount of halogenated hydrocarbons such as benzene, toluene, chlorine

f water is guaranteed. The secondary resin shell benzene, tetra- and decahydronaphthalene, trichloro

| g- arises within a few hours at a pH value, ethylene or carbon tetrachloride mentioned.

ip for urea formaldehyde about 2.0, for melamine- The proportion of encapsulated substance, based on

fts formaldehyde is around 4.0. The agitation is the total capsule mass and can be very different. π

H is usually not necessary, but you can use the resin - it can only be 20 percent by weight or up to 99 gell Formation by increasing the temperature to 40 to 60 C are weight percent. Preferably it is jell accelerate. 25 but 70 to 95 percent by weight. Depending on the application

The resulting capsule masses or suspensions can use the walls of the primary capsules longer

contained by the combination of small capsules from or .veniger are strengthened. The walls can

i | mostly formed clusters with a diameter of less than 1 μ. Depending on whether they are made hard or flexible. Also lets

The degree of porosity of the capsule walls depends on the amount of aminoplast precondensate added

low surface activity one obtains capsules with 30 set as desired. T

y different wall thicknesses, different tightnesses The finished capsules can, provided they are used as ^ r

and various mechanical destructibility. wants to use such by Abfütrieren and / or η

The amounts used of the reactive surfactant, the amino drying z. B. also spray drying of the adhering C.

plastvorkondensats and the substance to be encapsulated the liquid are freed. The dry capsules ν

can be very different, depending on the application 35 represent a fine, free-flowing powder. You can

purpose of the capsules and the type of encapsulation also as a suspension in a liquid, as a shaped i _t

Substance. For encapsulating liquid substances, compressed into tablets, as a coating on a body >

it has proven to be useful, processed on a 100 weight surface or in some other way parts of liquid 5 to 50 parts by weight of reactive surfactant, in which the capsules are initially used as such and 10 to 50 parts by weight of aminoplast precondensate 40 are retained. i

to use. In the case of solid substances to be encapsulated, the capsules have a very long shelf life. Even tempe-

If the lower limits of these quantities are around 100 ° C, they do not interfere with the π

Usually a little higher, i.e. H. to 100 parts by weight of solid capsule quality, provided that there are no heat-sensitive ones Substance is used z. B. each 30 to 50 weight substances have been encapsulated.

share reactive surfactant and aminoplast precondensate. The 45 The encapsulated, finely divided substance can k

Parts by weight of reactive surfactants and amino acids are released from the capsules in various ways refer here of course to the. Usually this is done mechanically, by, r

the dry product. Rupture of the capsule wall by applying pressure to this ' * <

In the method according to the invention, the overuse can be used. Furthermore, the substance can, especially if

guidance of the reactive surfactants or the aminoplast - it is not liquid, also by dissolving the capsule

precondensates of low surface activity in the wall with a suitable solvent, by c

irreversibly insoluble state due to various- shear forces, friction, heat, ultrasound, enzymes or i;

similar measures initiated and brought to an end by slow diffusion through a partially intact> .;

will. Mention should be made, in particular, of increasing the volume of the capsule wall being released. τ

Temperature, setting of certain pH values, to 55 As a material to be encapsulated according to the invention

set of substances that come with the surfactants or proper process solid, liquid or

Aminoplast precondensates with the formation of high-molar and gaseous substances are possible. r

to implement kular products, and above all the addition of solids must be in the presence of the reactive ten-

of so-called curing catalysts, which dispersed acidic sides and optionally by grinding react. 60 are comminuted to such an extent that a stable dispersion ■

In the event that it is encapsulated in an aqueous medium. ■

is, the pH of the preparation is advantageous. As dispersed solids, the various-;

2 to 5. The most suitable active ingredients such as pigments, fillers and pests are suitable for adjusting the pH value aliplatic, low molecular weight carboxylic acids, anti-inflammatory agents, fragrances, fats, waxes, such as formic, acetic or citric acid or paraffin, fertilizers or pharmaceuticals are used inorganic acids such as the salt or phosphorus are. Come as liquid substances to be emulsified acid, also acidic or hydrolyzable salts such as undiluted liquid active ingredients such. B. paraffin oil Aluminum sulfate, titanium oxychloride, magnesium chloride, or solutions of liquid or solid active ingredients in

suitable solvents into consideration. Liquid substances which have a high boiling point are generally preferred have or are of low volatility. Examples are phthalic acid dibutyl ester and phosphoric acid trikresyl ester, chlorinated diphenyl, called. Furthermore, other, less volatile, water-insoluble solvents, such as. B. Petrol, toluene or xylene can be considered.

The capsules produced by the process according to the invention are particularly suitable for production of pressure-sensitive copier papers. Here, dye formers are optionally used together with Encapsulated and antioxidants or UV absorbers applied to the paper or incorporated into the paper pulp. * 5

The capsules produced with ilen according to the invention coated papers are characterized by excellent storage stability. After a storage from over ID Ii at IOD C "will be unchanged good Copies with sharp, non-smeared writing- * or similar edges preserved

Parts and percentages in the subsequent manufacturing yorsclinficn and examples are by weight

25th

Manufacturing regulations for the in the examples used reactive surfactants

I 206 parts of 36.5 ″ aqueous formaldehyde, 170 parts of n-butanol and 60 parts of urea are mixed with 8 parts of 25 ″ ammonia and heated to 96 ° C. for 2 hours in a stirred flask with a descending condenser, a total of 32 parts Distill off n-butanol-water. Now cool to about 50 ° C. and add 1 part of 85% phosphoric acid, dissolved in 20 parts of n-butanol. Then heat to 80 ° C. in vacuo, with water and n The water is separated from the distillate, while the n-butanol runs back into the reaction vessel. After 4 h the product is practically anhydrous and miscible with benzene in any ratio. Now neutralize by adding 5 parts of triethanolamine and evaporate in a vacuum to 212 parts, whereby the product is obtained, which is referred to as varnish resin A in the following.

212 parts of urea-formaldehyde-butanol varnish resin A (corresponds to 1 mol of urea) are heated to 120 to 130 ° C. with 177 parts of polyethylene glycol with an average molecular weight of 1540 until the product has become clearly soluble in water. About 24 parts of butanol are distilled off during this process. 35 parts of triethanolamine are then added and the mixture is heated at 120 ° C. for 1 h. The condensation product obtained is treated with enough distilled water to produce a 50 °, pale yellowish, clear solution which can be further diluted with water. The product proves to be an excellent emulsifier in alkaline (pH = 9.0) or weakly acidic solution (pH = 5.0). Strong acid cross-links, especially at higher temperatures. About 6 parts of insoluble resin are formed from 100 parts of 50% surfactant solution.

II. 390 parts of hexamethylolamine hexamethyl ether. corresponding to 1 mol of melamine are mixed with 372 parts (2 mol) of dodecanol and 1540 parts (1 mol) of polyethylene glycol of the average molecular weight 1540 in the presence of 3.35 parts of 85% phosphoric acid Heated for 1 h to 115 to 130 C, with 97 parts of methanol distill off. The reaction product is neutralized with 10 parts of triethanolamine. One receives a waxy surfactant, easily soluble in water. Its aqueous solutions foam and exhibit excellent properties Emulsifying and dispersing effect.

III. 212 parts of the urea-formaldehyde-Bulanol lacquer resin A described in Regulation I (corresponds to 1 mol of urea) are heated to 85 to 90 ° C. in vacuo with 70 parts of butyl glycolic acid and 4 parts of glacial acetic acid until 42 parts of n-butanol have distilled off the mixture is stirred under reflux at 100 ° C. for 1 hour. Finally, the reaction product is diluted with 140 parts of ethanol, 35 parts of solid potassium hydroxide are added and the mixture is refluxed for 15 minutes, the ester groups being saponified. After evaporation in vacuo, 225 parts of a solid, slightly brownish substance which is readily soluble in water are obtained. If the strongly foaming solution is mixed with a little acid, a crosslinked product which is insoluble in alkali precipitates out.

IV. 126 parts of melamine are dissolved in 590 parts of 36.5% aqueous formaldehyde containing ethanol at 60.degree. C. with the addition of 18 parts of 25% ammonia. The mixture is heated to 80 ° C. and 132 parts of a mixture of methanol and water are distilled off in vacuo for about 20 minutes. 490 parts of n-butanol are now added and the mixture is distilled further in vacuo, the water-n-butanol mixture which passes over being separated. The n-butanol runs back into the reaction vessel, while 118 parts of the aqueous layer separate out. Are added 3 parts of 85 ° / _o formic acid dissolved in 5 parts of n-butanol, and distilled to now throughout 452 parts of n-butanol from which entrains the last traces of water. 532 parts of a viscous, colorless resin are obtained, which can be mixed with benzene in any ratio and is referred to below as lacquer resin B.

532 parts of melamine-n-butanol varnish resin B (containing 1 mol of melamine) are heated with 104 parts of ethanolamine while stirring for 1.5 hours to 120 ° C. and then for 1.5 hours to 135 to 140 ° C., with 76 Distill off parts of n-butanol. After cooling, 560 parts of soluble product are obtained of a clear, viscous, 10 ° _t, acetic acid easily. Its acidic solutions have excellent emulsifying properties. At a pH value of 4.0 and a slightly elevated temperature, the formation of an insoluble resin occurs. These properties characterize the product as a reactive surfactant. The product has a solids content of 80 to 85%. In a 5% aqueous solution, this reactive surfactant lowers the surface tension of the water from 72.75 to 37.6 dynes / cm

V. 445 parts of the varnish resin B from regulation IV are mixed with 50 parts of a polyethylene glycol with an average molecular weight of 4000. The mixture is heated to 95 to 100 ° C. and 3 parts of glacial acetic acid are added. The heating is continued at 95 to 100 ° C. until a sample of the reaction product dissolves clearly in water. 70 parts of trialkanolamine are then added, the mixture is stirred and heated to 120 ° C. for a further 2 hours. After cooling, a colorless, waxy substance which can be easily mixed with water at 60 ° C. is obtained. By adding the same amount of water and a little acetic acid, a 50% weakly cloudy surfactant solution with a pH of 8.1 to 8.2 is obtained. In a 5 ° aqueous solution, this reactive surfactant lowers the surface tension of the water from 72.75 to 41.0 dynes / cm.

609 683/151

ίο

example 1

1.1 Preparation of the primary emulsion

20.0 g of reactive surfactant according to regulation IV are added to a mixture of 98.0 g of water and 2.0 g of glacial acetic acid solved. Now 200.0 g of dye solution, consisting of 3.6 g of crystal violet lactone, 2.4 g of benzoyl-leuco-methylene blue are added in 97.0 g of chlorinated diphenyl and 97.0 g of paraffin oil, with a high-speed stirrer in the Emulsified reactive surfactant solution. The emulsion is mixed with 400 ml of water and with 6 ml of 85 ° phosphoric acid adjusted to a pH of 2.1. The diameter of the emulsified particles is about 1 μ.

1.2 Hardening of the primary emulsion

The primary emulsion remains at room temperature for 3 hours and at 60 ° C. for 2 hours. Now is adjusted to a pH of 6.0 with 24 ^u _u ammonia.

20th

1.3 Preparation of the secondary suspension

50.0 g of the primary capsule suspension (from 1.2) are diluted with 30 ml of water and, while stirring, with a solution of 10 ml of water and 7.0 g of an aminoplast precondensate, prepared by stirring 2.38 ρ melamine and 4 , 62 g of 37 ^o _o formaldehyde, is added at 60 C. In 5 ″ yg aqueous solution this aminoplast precondensate lowers the surface tension of water from 72.75 to 57.5 dynes / cm. The foam volume of such a solution after shaking for 1 min is practically zero. The suspension is mixed for 10 min at room temperature.

1.4 Reinforcing the primary capsules

0.5 ml of 85% phosphoric acid are added, the temperature is increased to 40 ° C. and stirred for 30 minutes at this temperature. One stirs now during 1 h at 60 ° C and then cools down to 20 ° C. With 24 "ammonia, the suspension is reduced to one pH adjusted to 9.0. The particle size of the capsules is still around I μ.

A very fine powder is obtained by drying the capsule mass. This powder can be put back in water dispersed and painted on paper. The capsules are still with after more than 300 hours of storage 100 C of practically unchanged quality and can be used for the production of copy papers.

In addition to what is described under 1.3, aminoplast precondensates can, under the same conditions, be as follows Composition can be applied with success:

a solution of 20 ml of water and 18.0 g of aminoplast precondensate verseUt. The suspension is heated to 40 ° C. and acidified with 0.9 ml of 85% phosphoric acid and stirred for 30 min at this temperature. 5 The mixture is then stirred for 1 h at 65 ° C. and then cooled down to 20C. With 24% ammonia, the Suspension adjusted to a pH of 9.0. The particle size of the capsules is about 1 μ. Also these capsules are gas-tight and can be isolated as a powder 10.

The aminoplast precondensate is made from the following components:

a) 1.23 g of melamine
2.86 g urea

13.95 g formalin (37 ⁰ yrs

or

b) 0.67 g of melamine
3.17 grams of urea

14.16 g formalin (37 ⁰ J

The individual components are stirred together at 60 ° C. for 30 minutes.

Example 3

75.0 g of the primary capsule suspension become 1.2 diluted with 45 ml of water and with stirring with a solution of 15 ml of water and 14.0 g of aminoplast precondensal offset. The suspension is stirred for 15 minutes at room temperature. Be now 0.7 ml of 85% phosphoric acid was added, the temperature was increased to 40 C and at this for 30 minutes Temperature stirred. The mixture is then stirred for 1 h at 60.degree. C. and then cooled to 20.degree. With 24% Ammonia, the suspension is adjusted to a pH of 8.5. The particle size of these capsules is also 1 μ. The capsules are practically gas-tight and can be isolated as a powder.

The aminoplast precondensate is produced by man

a) 0.50 g of melamine
3.00 g thiourea

10.50 g formaldehyde (37%)

or

b) 0.73 g of melamine
2.17 g thiourea

11.10 g formaldehyde (37%)

for 30 minutes at 6O ⁰ C is stirred together.

melamine
in g

formaldehyde
(37%) in g

Mole ratio
Melamine? U
formaldehyde

1.95

1.655

1.435

5.05

5.345

5.565

Instead of the reactive surfactant according to regulation IV A reactive surfactant according to one of the regulations I to 111 or V can also be used with equal success will.

Example 2

100.0 g of the primary capsule suspension according to 1.2 are diluted with 55 ml of water and mixed with Example 4 with stirring
4.1 Preparation of the primary emulsion

30.0 g of reactive surfactant according to regulation V are dissolved in 30 ml of water and 0.5 ml of 85% phosphoric acid. Now 100.0 g of dye solution, consisting of 3.6 g of crystal violet lactone, 2.4 g of benzoyl leuco

Methylene blue, 97.0 g trichlorodiphenyl and 97 g paraffin oil with a high speed stirrer in the reactive surfactant solution emulsified. The emulsion is now made with 100 ml of water and 2.5 ml of 85% phosphoric acid offset.

4.2 Hardening of the primary emulsion

The primary emulsion remains at room temperature for 2 hours and at 60 ° C. for 1.5 hours. While curing

another 100 ml of water are added. At the end is adjusted to a pI-1 value of 6.0 with 24% ammonia.

4.3 Preparation of the secondary suspension

50.0 g of the primary capsule emulsion from 4.2 are diluted with 30 ml of water and, while stirring, with a Solution of 10 ml of water and 10.0 g of aminoplast precondensate (prepared by stirring for 30 min of 15.1 g of melamine and 29.25 g of 37% formaldehyde at 60 C). The suspension is stirred for 30 minutes at room temperature.

4.4 Strengthening the primary capsules

There are added 0.5 ml of 85 "" phosphoric acid added, the temperature raised to 40 C and for 1 h, and this for a further hour at 60 C with stirring. The suspension is cooled to 20 C and 24 _"o strength ammonia adjusted to a pH of 9.0. The particle size of the capsules is about 1 μ.

Example 5

50.0 g of the primary capsule suspension according to 1.2 are heated to 40 ° C., with 30 ml of water and 0.5 ml of 8. *>'! _o iger phosphoric acid added. A solution of 10 ml of water and 10.0 g of aminoplast precondensate a) / u is now allowed to drip and stirred at 40 ° C. for 30 minutes. A solution of 10 ml of water and 10.0 g of aminoplast precondensate b) is then added dropwise and the mixture is stirred at 40 ° C. for 30 minutes and at 60 ° C. for 1 hour. It is now cooled to room temperature and the suspension is adjusted to a pH of 9.0 using 24% ammonia. The particle size of the capsules is about 1 μ.

Production of the aminoplast precondensates

a) 45.0 g of urea and 91,0g 37 ° _o sodium formaldehyde h at a pH value of 7.9 to 8.0 for 1 at 80 to 85 C stirred.

b) 15.0 g urea, 81.0 g 37 ° formaldehyde and 5 ml of 20 "strength triethanolamine are stirred at 60 ° C. for 30 minutes.

Example 6

ISO g of a 40% solution in ethyl acetate of an adhesive made from n-butyl acrylic ester, vinyl acetate and acrylic acid are mixed with 70 g of tricryl phosphate and emulsified using a high-speed stirrer in a solution of 100 g of 50% reactive surfactant according to regulation I in 150 g of distilled water . The emulsion is then diluted with 500 g of water. The emulsion contains particles approximately 1μ in diameter. The emulsion is freed from ethyl acetate by evaporation in vacuo and then adjusted to 1100 g with distilled water. By adding 10 g of 85% phosphoric acid in 140 g of water, the pH of the emulsion drops to 2.0 to 2.5. The mixture is warmed to 35 ° C. and kept at this temperature for about 8 hours, the emulsion being kept in gentle motion. A solution of 17.5 g of urea in 35 g of 37% formaldehyde and 197.5 g of distilled water is then added to the primary capsule mass and stirring is continued for 30 minutes. The secondary capsule mass strengthened in this way is neutralized by adding ammonia. You apply it to paper and get a smooth, non-sticky surface. However, if the coated paper is pressed against a base, the capsules burst and an intensive adhesive effect immediately occurs. The capsules are made up of approximately 88% adhesive and 12% resin shell. 5

Example 7

30 g of a styrene-butadiene copolymer are dissolved in 70 g of toluene and 44 g of dioctyl phthalate and 6 parts of Solvent Black 3 CI 26 150 are added to the solution. The viscous dye solution obtained is emulsified in a solution of 110 g of 50% reactive surfactant according to regulation V and 80 g of water, which has been adjusted to a pH of 5.5 to 6.0 by adding 85% phosphoric acid . The means of a high-speed emulsion prepared it is diluted with 450 g of distilled water and makes it available by further addition of 85 ° _o phosphoric acid to a pH value of 2.0 a. The mixture is heated gradually under

ao stirring to 60 to 65 ° C. and held at this temperature for 1.5 hours, during which the surfactant is hardened. Man cools down to 20 ° C. and adds a further 1600 g of water and 40 g of a solution, which is then dissolved of 13.8 g melamine in 26.2 g 37% formaldehyde at 60 C. Now stir slowly for 3 h where the temperature should rise from 20 to 60 C. Finally, it is cooled to 20 C. The capsule mass is sucked in on a suction filter and then disperses the filter cake in as much 3 ", ', iger polyvinyl alcohol solution, that 1000 g of a thin paste arise. Applying this paste to paper gives a dark one colored but absolutely smudge-proof coating, which has a black copy-through effect on any other paper generated.

Example 8

100 g of the pigment from diazotized! l-Amino-2-methyl-4-chlorobenzene, coupled with 2-hydroxynaphthalene ^ Vcarboxylic acid ^ '- methyW-ehlor- phenylamide, in 400 g a 10 "solution of the reactive surfactant according to the instructions II so finely divided that the dispersion after dilution with water to 1250 g through filter paper runs through. The diluted pigment suspension is added as much phosphoric acid or formic acid as that their pH drops to 2.5. The mixture is left to stand for 2 hours at room temperature and heated with stirring 60 C and holds at this temperature for 2 h. It is then cooled to 20 ° C. and a solution of 22.5 g is used Melamine in 56 g of 37% formaldehyde and 171.5 g of water are added and this increases to 5.0 The pH is brought back to 4.0 by adding acid. The mixture is heated with careful stirring 60 C and holds for 3 h at this temperature. The encapsulated pigment suspension can be neutralized with ammonia before they are vacuumed, washed out and dried on a suction filter. You get about 140 g of fine-grain, strongly colored pigment powder, which compared to the crude pigment was significantly improved Exhibits oiliness (insolubility in organic solvents). A similar result is obtained if the reactive surfactant III is used instead of the reactive surfactant II.

Example 9

30.0 g of the reactive surfactant according to Regulation IV (80 to 85 ° strength) are dissolved in 143.0 g of water and 3.0 g Dissolved glacial acetic acid. In the aqueous solution 2000 g

3% dye solution (made from 36.0 g of crystal violet U-lactone, 24.0 g benzoylmethylene blue, 970.0 g trichlorodiphenyl and 970.0 g paraffin oil) emulsifiable. Care must be taken during emulsification that the temperature does not rise above 25 ° C.

400 ml of water and 10.1 g of 85% phosphoric acid are then added to the emulsion. You let them Emulsion 2 Ii stand at room temperature and then stirred for 1.5 h at 60 ° C. Finally, one sets with 24% ammonia to a pH of 6.0 and dilute the suspension with 480 ml of water.

Production of the aminoplast precondensate

54.6 g of melamine and 105.0 g of formaldehyde (37%) are stirred at 60 ° C. for 30 minutes. The clear solution is now diluted with 160 ml of water.

The condensate solution is now allowed to drip into the primary suspension within minutes, Stirred min at room temperature and acidified with 8 ml of 85% phosphoric acid. The suspension it is stirred for 30 min at 40.degree. C. and 1 liter at 60.degree. It is now cooled to room temperature and with 24% Ammonia adjusted to a pH of 9.0. The suspension is filtered off and the residue over Dried overnight at 65 ° C. in a vacuum drying cabinet. Yield: 267.8 g capsule powder.

This results in:

200.0 g dye solution 74.7%

67.8 g capsule mass 25.3%

Example 10

a) 15 g of the reactive surfactant according to regulation IV are dissolved in 72 g of water and 1.5 g of glacial acetic acid.

In the aqueous solution is a solution of 15 g of 2,4,4'-TrichIor-2'-hydroxydiphenyl ether in 85 g trichlorodiphenyl emulsified. The emulsion is diluted with 200 ml of water and with 3 ml Acidified phosphoric acid (85%). The emulsion is allowed to stand for 2 hours at room temperature and then stir for 2 h at 60 ° C. Finally, the pH is adjusted to 24% ammonia of 6.0 a.

b) 100 g of the above primary suspension are diluted with 100 ml of water and added with stirring Room temperature with a solution of 20 g of the aminoplast precondensate according to 1.3 in 60 ml Water added. The suspension is stirred at room temperature for 0.5 h and then made by addition of 0.5 ml of phosphoric acid (85%) to a pH of 4.6. To complete the reaction The reaction mixture is stirred for 1 hour at 40.degree. C. and for a further 1 hour at 60.degree the capsule suspension cooled to room temperature and treated with concentrated ammonia adjusted to a pH of 7. Filtration of the suspension gives the capsule mass which is dried in a vacuum cabinet at 60 C.

A solution of 5 g of hexachlorophene in 95 g of trichlorodiphenyl can also be used under the same conditions be encapsulated.

Example 11

a) 30 g of the reactive surfactant according to regulation IV are dissolved in 160 g of water and 1.5 g of glacial acetic acid. 30 g of tri-butyl phosphate are emulsified in the aqueous solution. The emulsion is diluted with 350 ml of water and adjusted to a pH of 3.1 with a solution of 6 ml of concentrated phosphoric acid in 50 ml of water. The emulsion is then stirred for 1.5 hours at room temperature, then for 1.5 hours at 40.degree. C. and finally for 2 hours at 60.degree. The mixture is then allowed to cool to about 25 ° C. and a pH of 6.0 is set with 12 ml of concentrated ammonia.
b) 7 g of the aminoplast precondensate according to 1.3 in 10 ml of water are added to 200 g of the primary suspension prepared according to a) within 5 minutes at room temperature and with stirring. The mixture is then stirred for 0.5 h at room temperature, then adjusted to a pH of 3.4 with 3.4 ml of concentrated phosphoric acid (85%) and then stirred for 1 h at 40 ° C. and 2 h at 60 C. The reaction mixture is then cooled to about 25 to 30 ° C. and adjusted to a pH of 8.0 with 12.6 ml of concentrated ammonia.

The capsule mass, which is dried at 60 ° C. in a vacuum chamber, is obtained by filtering the suspension will.

Under the same conditions, a solution of 0.9 g of crystal violet laetone in 29.1 g of tri-n-butylpliosphate or e ^; Encapsulate the solvent mixture of trichloroethyl phosphate and trichlorobenzene.

Example 12

a) 25 g of the reactive surfactant according to regulation IV are dissolved in 125 g of water and 2.5 g of glacial acetic acid. 100 g of tris (2,3-dibromopropyl) phosphate are added to the aqueous solution emulsified. The emulsion is diluted with 500 ml of water, then 0.5 h at Stirred at room temperature and adjusted to pH with 10 ml of concentrated phosphoric acid (85%) set of 3.2. The emulsion is then stirred for 0.5 h at 25 ° C., 45 min at 40 ° C. and 2 h at 60 ° C. After cooling to 25 ° C., the resulting suspension is concentrated with 18.0 ml Ammonia adjusted to pH 6.0.

b) 800 g of the primary suspension prepared according to a) are diluted with 100 ml of water and placed within 10 min at room temperature and with stirring 100 g of the aminoplast precondensate according to 1.3 added in 100 ml of water.

The suspension is stirred for 0.5 h at room temperature and made up with concentrated phosphoric acid A pH of 3.0 is then stirred for 0.5 hour at 25 ° C. for 1 hour at 40 ° C. and for a further 1 hour at 60 °. After the suspension has cooled to 25 ° C., a pH of 6.0 is set with concentrated ammonia. The capsule mass is obtained by filtering the suspension and is dried at 60 ° C. in a vacuum cabinet will.

Example 13

g of the reactive surfactant according to regulation I are diluted with 100 g of water and 260 g of commercial petroleum are emulsified in it using a high-speed stirrer. The emulsion obtained is further diluted with water up to 2500 g. The diameter of the petroleum droplets is no more than 1 μ. By adding 85% H ₃ PO ₄ , the pH of the emulsion is adjusted to 3.5 and the mixture is heated to 60 ° C. for 2 hours, with no or only

stirs very weakly. A mixture of 33 g of urea and 87.5 g of 37% formaldehyde is then added, the pH value is adjusted to 3.0 by further addition of acid and the emulsion is ^{stirred at 60 °} C. for about 4 to 6 hours. The capsule mass formed One sucks on the suction filter, and washed sb with distilled water. Neither in the filtrate nor in the wash

16

water can be detected free petroleum, so that the encapsulation is practically complete. the Capsule mass is then at ordinary or slightly elevated temperature, e.g. B. at 60 C, dried. Man ι receives a solid, colorless powder that contains over 80% petroleum and, for example, as a solid fuel can be used.

Claims (1)

Protective colloids to support the emulsifiable Claim: ^ ^. ^ ^ _{A combination of a PoIvrneri} _ Process for the "production of microcapsules ^ - ^ ΓΓ ^^ Αί d ^ Th ^ Ten ^ T ^ n ^ TtSlTeint harvest for the production of double-walled Lp e nde ^ aterlal in a liquid in counter-capsules, after which first a ^ -narkapsule-Wt of a reactive surfactant is dispersed, the shell is polycondensed by dissolving a monomer in an oil, reactive surfactant, which thereby dispersing the solution in a vassngen Ge of a star suspensionL of microcapsules a xo hydrophilic ,, film _. idend; Matenah » mitJjchteto aminoplast precondensate lower surface geb.ldet oer polymerization and then added colloidal Mate activity and also polycondensed .al by Koazervat.on to de Pnmarkapseluand ^b _is deposited and is excavated with formaldehyde, is cured. This process does not result in chemically bonded double walls, but only adhering to one another. tending walls. These disadvantages are in the process of making microcapsules with reinforced, polymeric A method for the production of microcapsules, capsule walls largely avoided, if in accordance with the invention the finely dispersed substances are encapsulated in a tive surfactant with the help of reactive ao according to the material to be encapsulated, is from the German liquid in the presence of a reactive surfactant from Sperschen Offenlegungsschrift 15 19 771 known. The suspension of microcapsules produced by this process has, however, only weak capsule walls which are easily penetrated or mechanically damaged and also polycondensed
can be died. One coated for 60 h at HOC According to the German Offenlegungsschrift 14 44 414 paper carried out aging test shows that the after one can use water-insoluble, solid or liquid sub- dem Method of the German Offenlegungssehrift encapsulate punch, if you can use a quick-15 19 771 single capsule wall after 1 h running stirrer in the solution of e.g. B. from urine 30 is unusable, while according to the invention hergestoff and formaldehyde, prepared in the usual way, left the capsule walls practically unchanged after 60 hours Primary condensate dispersed and the dispersion remain at. continued stirring to acidify to form resin. These further comparative tests have shown that at known working method leads to the use of a reactive surfactant as an adhesive for several reasons unsatisfactory result. The solution of this 35 can be encapsulated peacefully, with the cape primary condensate exhibits only a modest dispersion mass when applied to paper, not a smooth one j. greed, so that you only give relatively coarse capsules sticky surface and after application of at least a few μ diameter can be produced. Pressure on the coated paper creates a strong adhesive. However, the smaller the capsules, the better and the more effective it is. On the other hand, if you use more evenly, your content can come into effect. In addition, the intensive surfactant necessary for the maintenance published patent application 14444114 to reactivate the distribution of the particles impairs a greasy, two-phase system which, when stirred, contains the formation of a uniform capsule that does not contain any adhesive and on th wrapping. It is therefore difficult. Capsules of your paper give a sticky surface,
to produce sufficient tightness and strength. 45 In the method according to the invention, the In addition, substances that are relatively encapsulating material in the form of fine particles in the P are difficult to disperse, 7. B. viscous adhesives, dispersed in solution of the reactive surfactant and the II the usual primary condensate solutions at all dispersion used reactive surfactant in an insoluble not be brought into distribution. If you try to transfer the Liches resin. On the thus formed relative dispersion of such materials by the addition of emulsifiers 5 ° thin-walled capsules, a second resin layer \ Gators conventional type to force, it is found, generates or intensifies the skin first formed by encapsulation that subsequently no longer it is possible that the capsule dispersion formed is one solution, since the emulsifier adds the surface of the particles to the usual aminoplast precondensate and keeps this Ί occupied. also polycondensed. While the formation of the learner is required in the German Offenlegungsschrift 55 original emulsion or dispersion a powerful j 18 17 316 a process for the production of capsules agitator, the actual encapsulation, j can be described with multilayered shells, with two ie hardening of the reactive surfactant as well as the education liquid grains in different phases of the next / wide layer practically without components, one of which is hydrophilic and the other stirring, since the particles formed are so small that they are hydrophobic, are used. Each envelope ⁶ ° are subject to Brownian movement in such a way that the leaks and thus the homogeneity of the suspension, including the last capsule wall formed, are sealed without stirring. This applies in particular, with a new one in the outer phase whenever the specific weight of the encapsulated monomer is used. The capsule substance does not deviate significantly from that of the surrounding solution wall due to the reaction of an external phase with the compound. inner phase formed. This method, too, is particularly necessary for the method according to the invention either high stirring speeds for suitable reactive surfactants contain methylol groups right maintenance of the dispersion or the addition of aminoplast precondensates, which