FI104794B - Microcapsules - Google Patents

Abstract

Microcapsules are obtainable by polymerisation of A) 30 to 100% by weight of one or more C1-C24-alkyl acrylates and/or methacrylates (monomers I), B) 0 to 80% by weight of a bifunctional or polyfunctional monomer (monomers II) which is soluble in solvents which are insoluble or sparingly soluble in water, and C) 0 to 40% by weight of other monomers (monomers III), the solvent, if any, being in the form of a stable oil-in-water emulsion together with the monomers and a free-radical initiator as the disperse phase, and the polymerisation being initiated and controlled by the thermal decomposition of the free-radical initiator. The products preferably serve for the manufacture of pressure-sensitive recording materials.

Description

104794

microcapsules

The invention relates to microcapsules characterized in that they are obtained by polymerization of 5 A) from 30 to 100% by weight of one or more C1-24 alkyl esters of acrylic acid or methacrylic acid (monomers I), B) from 0 to 80% by weight of bi- or a polyfunctional monomer (monomer II) which is soluble in a solvent insoluble or slightly soluble in water; and 10 C) 0 to 40% by weight of other monomers (monomers I-II), wherein the solvent is present alone or in combination with monomers and free radicals. as the dispersed phase with the initiator in a stable oil-in-water emulsion, and the polymerization is initiated and controlled in stages by thermal decomposition of the free radical initiator by raising the temperature.

The present invention also relates to a process for the production of microcapsules, the use of color-forming micro-capsules for the manufacture of pressure-sensitive recording materials, and these recording materials.

EP-A-026 914, EP-A-133 295 and EP-A-218 887 relate to microcapsules based on melamine-formaldehyde resins, recommended for use in pressure sensitive recorders. · 25 materials.

In addition, a method for manufacturing microcapsules is based on in situ polymerization. Microcapsules are produced, for example, by the process described in EP-A-198 089 by first preparing monomers such as acrylic. 30 containing a solution of fatty acid esters, a water-insoluble solvent, a free radical initiator, a polymer and an encapsulating material, and then converting this solution into a stable oil-in-water emulsion. The polymerization of the monomers is then initiated by increasing the temperature, and the resulting polymers form capsule walls which seal the remaining soluble encapsulant dissolved in the organic solution.

Microencapsulated materials include colors, detergents, printing inks, perfumes, adhesives, pharmaceuticals, agrochemicals, fertilizers, fats, oils, nutrients, enzymes, liquid crystals, paints, anticorrosives, preservatives, catalysts, chemical reactants.

The microcapsules 10 of the present invention are prepared from 30 to 100% by weight, preferably from 30 to 95% by weight, of one or more C1-24 alkyl esters of acrylic and / or methacrylic acid as monomer I.

In addition, microcapsules of the present invention may also be formed using up to 80 to 15% by weight of monomer II, preferably 5 to 40% by weight, of a bi- or poly-functional monomer soluble in a water-insoluble or water-insoluble solvent, and other monomers III Up to 40% by weight, preferably up to 30% by weight.

Suitable monomers I are C1-24 alkyl esters of acrylic and / or methacrylic acid. Particularly preferred mono-. mers I are methyl, ethyl, n-propyl, n-butyl ♦ · ♦ and 2-ethylhexyl acrylates and methacrylates. Preferred are: isopropyl, isobutyl, sec-butyl and: tert-butyl acrylates and methacrylates. It is, however

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:. * ·· It is also possible to use n-pentyl, n-hexyl, n-hep-, 1'-yl, n-octyl and lauryl acrylates and methacrylates.

Suitable additional monomers II are bi- or polyfunctional ·, ·, thionic monomers which are soluble in water-insoluble, · ··· φ insoluble or sparingly soluble solvents; these monomers are mainly divinyl and polyvinyl monomers, which cause the capsule walls to network during polymerization.

104794 3

Preferred divinyl monomers include ethanediol di-acrylate, divinyl benzene, ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, methallyl methacrylamide and allyl methacrylate. Particularly preferred are propanediol, butanediol, pentanediol and hexanediol diacrylates or methacrylates.

Preferred polyvinyl monomers include trimethylol propane triacrylate and methacrylate, pentaerythritol triallyl ether and pentaerythritol tetraacrylate.

The crosslinking can also be carried out via groups capable of addition or condensation, optionally with the addition of at least bifunctional such groups, in which case the crosslinking reaction is carried out after the polymerization.

Monomers containing such groups include, for example, glycidyl acrylate and methacrylate, and in particular vinyl compounds containing amino, acetylacetone, epoxy or methylol groups.

The functional groups of these monomers may be crosslinked, for example, via bi- or polyfunctional epoxides, amines and alcohols, preferably. via urea and melamine-formaldehyde precondensates.

* »» * ·; · 1 Good results in post-production network M ·

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: .1 In particular, acetoacetoxyethyl methacrylate is used as functional monomer and formaldehyde or glutaraldehyde as the crosslinking component.

Any other monomers suitable as monomers III are preferred, styrene, α-methylstyrene, β-m ···, styrene, butadiene, isoprene, vinyl acetate, vinyl propionate and vinylpyridine.

Particularly preferred monomers III are acrylic, · nitrile, methacrylamide, acrylic acid, methacrylic acid, · itaconic acid, maleic acid, maleic anhydride, N-vi-η 1 ♦ 104794 4-yl-pyrrolidone, 2-hydroxyacrylamide, -methylpropane sulfonic acid.

It is also possible to use N-methylolacrylamide, N-methylol methacrylamide, dimethylaminoethyl 5-methacrylate and diethylaminoethyl methacrylate.

The microcapsules of the invention are prepared by polymerizing the monomers I, II and III, which polymerization is initiated and controlled by raising the temperature to a level where the free radical initiator decomposes. This method is characterized by what is set forth in the characterizing part of claim 5.

Suitable free radical initiators for use in the polymerization reaction include conventional peroxy and azo compounds, which are preferably used in amounts of from 0.2 to 5% by weight, based on the weight of the monomers.

Preferred free radical initiators include tert-butyl peroxineodecanoate, tert-amyl peroxypivalate, dilauryl peroxide, tert-amyl peroxy-2-ethylhexanoate, 2,2'-azobis (2,4-dimethyl) valeronitrile, 2,2'-azobis ( 2-methylbutyronitrile), dibenzoyl peroxide, tert-butyl per-2-ethylhexanoate, di-tert-butyl hydroperoxide, 2,5-dimethyl-11, 2,5-di (tert-butyl peroxy) hexane and cumene hydroperox:: -: cide.

Particularly preferred free radical initiators are di (3,5,5-trimethylhexanoyl) peroxide, 4,4'-azo-bisobutyronitrile, tert-butyl perpivalate, and dimethyl. 2,2-azobisisobutyrate. These have a half-life in the temperature range of 30 ° C to 100 ° C for 10 hours.

The monomers and the free-radical initiator may be dissolved in a water-insoluble or a water-insoluble solvent, whereby the resulting solution forms a dispersed phase in an oil-in-water emulsion. However, it is also possible to first disperse the solvent and add the monomers and the free-radical initiator to the dispersion. Yet another possibility is to disperse the solvent and the monomers and then add only the free radical initiator. Of course, the solvent may also contain other ingredients such as coloring agents.

Suitable water-insoluble or water-insoluble solvents include natural oils, synthetic oils and solvents having a boiling point of 80 to 350 ° C, preferably 150 to 350 ° C. The oil-in-water emulsion preferably contains from 20 to 60% by weight of such oil.

Preferred water-insoluble or water-insoluble solvents include benzines, mineral oils, paraffins, chloroparaffins, hydrofluorocarbons, peanut oil, soybean oil, chlorinated biphenyls, tributylphosphate, dibutylmalibate, o-dichloro, o-dichloro -ksylyyli-ethane.

Substances such as coloring agents have particularly good solubility in a water-insoluble or water-insoluble solvent having a boiling point in the range of from 150 to 350 ° C; examples of these are dibutyl phthalate, diisoheptyl phthalate, dioctyl phthalate, alkyl naphthalenes and partially hydrogenated terphenyls, and, especially diisopropyl naphthalene, dodecyl benzene and mixtures thereof.

* · *: 25 The substances contained in the capsules are especially those mentioned above on page 2, and in particular coloring agents.

• ·. ·; ·. Suitable colorants for encapsulation are, for example, colorless or poorly colored compounds which, in the presence of acids, become colored, as is the case, for example, with many phthalides, which · · * · ·· * when opened, form colored open-chain acids.

Preferred coloring agents are 3,3-bis (p-dimethyl-? 35-liaminophenyl) phthalide, 3- (p-dimethylaminophenyl) -3-? , 2-diraethylindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2-phenylindol-3-yl) phthalide, rhodamine-B-anilinolactam, 3-dimethylamino-7- methoxifluorane, p-nitrobenzoyl-leukomethylene blue, 3-methylpyrod-5 naphthopyran and 3-propylpyrodibenzopyran.

Particularly preferred are 3,3-bis (p-dimethylamino-phenyl) -6-dimethylaminophthalide and N-benzoyl-leucomethylene blue and mixtures thereof.

The coloring agents are generally used in amounts of 1-10% by weight, preferably 2-8% by weight, based on the weight of the oil phase of the emulsion.

Suitable acidic coloring agents include acidic clay, attapulgite, aluminum silicate, benzoic acid, chlorobenzoic acid, toluene acid, salicylic acid and 4-tert-butyl-15-salicylic acid, as well as especially kaolin and alkyl-substituted phenols.

The microcapsules of the invention may be prepared by conventional methods, for example, as described in EP-A-198 089.

Generally, the polymerization is carried out at a temperature of 20-100 ° C, preferably 40-80 ° C.

The polymerization is preferably carried out at normal pressure, but reduced or slightly increased pressure, for example 50 to 25,500 kPa, may also be used.

The reaction time is normally 1-10 hours, usually 2-7 hours.

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In general, the process is carried out such that water, protective colloids, ionic emulsifiers, water-insoluble or sparingly soluble solvents, and other substances dissolved in them, free radicals, · · *; the mixture of tiators and monomers is added simultaneously or sequentially, dispersed and heated with vigorous stirring to the decomposition temperature of the free radical initiator.

7 104794

The polymerization can be controlled by the temperature and the amount of free radical initiator.

Once the reaction temperature has been reached, the polymerization is preferably continued for about 2-6 hours to reduce the remaining monomer content.

Water-soluble polymers are preferred emulsifiers because they lower the surface tension of water from a maximum value of 73 mN / m to 45-70 mN / m and thereby ensure the formation of open capsule walls and capsules having a particle size of 1-30 μπι, preferably 3-12 μπι.

Preferred protective colloids are in particular cellulose derivatives such as hydroxyethylcellulose, carboxymethylcellulose and methylcellulose, polyvinylpyrrolidone and copolymers of vinylpyrrolidone.

Preferably, gelatin, acacia, xanthan gum, sodium alginate, casein, polyvinyl alcohol and partially hydrogenated polyvinyl acetate are used.

Generally, protective collars are used in amounts of 0.1 to 10% by weight, preferably 0.5 to 5% by weight, based on the weight of the aqueous phase of the emulsion.

Ionic emulsifiers may be added to improve the stability of the emulsions. It is especially important to add ionic emulsifiers when the microcapsule content of the dispersion is high, since without the addition of an ionic stabilizer, the microcapsules may agglomerate. These agglomerates if they are between 1 and. 3 μπι, reduce the yield of useful microcapsules, • · · or if they are larger than about 10 μπι in diameter, ... 3 0 increase the abrasion sensitivity.

Suitable ionic emulsifiers include, in particular: • · * · * · * polymethacrylic acid, sulfoethyl acrylate and methacrylate, sulfopropyl acrylate and methacrylate, N- (sulfoethyl) maleimide, 2-acrylamido-2-alkanesulfonic acid.

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8 104794 Polymers of styrene sulfonic acid or vinyl sulfonic acid.

Preferred ionic emulsifiers are naphthalenesulfonic acid and naphthalenesulfonic acid / formaldehyde condensates and especially polyacrylic acids and phenolic sulfonic acid / formaldehyde condensates.

Ionic emulsifiers are generally used in amounts of 0.1 to 10% by weight, based on the weight of the aqueous phase of the emulsion.

The polymerization conditions are preferably selected as the time generally used for the preparation of microcapsules having a diameter of 1 to 35 μττι, in particular 3 to 15 μπκ

The viscosities of the capsule dispersions are measured in seconds to the completion of a 100 ml dispersion of 4 mm from a 15-hole Ford cup in accordance with German standard DIN 53 211.

The microcapsule dispersions of the invention preferably have a solids content of 20 to 60% by weight.

The color forming mic-20 rock capsules of the present invention are used to make pressure-sensitive recording materials.

These materials are mainly stiffening papers impregnated with a color developer and coated with a microcapsule dispersion. pen pressure! '25 causes the microcapsules to break, whereby the color: * ·. · Dosers or color-forming components become colored as they develop.

• ·. ·; ·. The · · · microcapsule dispersions prepared in accordance with the present invention can be used directly to coat the paper… or the dispersions can be dried, for example, by spray drying and redispersed before use.

• * • · «i · 9 104794

EXAMPLES Preparation of Color Forming Microcapsules Example 1

A mixture of 5 1280 g of water 20 g of polyvinylpyrrolidone K90 15 g of phenolsulfonic acid / formaldehyde condensate 522 g of diisopropylnaphthalene 10 522 g of dodecylbenzene 48 g of 3,3-bis (p-dimethylaminophenyl) -6-dimethyl- 36 g) and a mixture of N-benzoyl-leucomethylene blue (12 g) 168 g of methyl methacrylate 15 g of butanediol acrylate 1.4 g of azobisisobutyronitrile 2 g of dimethyl 2-azobisisobutyrate were dispersed at room temperature for 20 minutes. The dispersion was then heated while continuing to disperse at 60 ° C and held at this temperature for 1.5 hours. It was then heated at 65 ° C for 4 hours to complete the polymerization, then the dispersion was cooled.

The dispersion obtained had a solids content of 49.1% by weight and a flow time from the Ford cup of 101 seconds.

: 25 The microcapsules had an average particle size of 5.6 μιτι with a practical variation in size ranging from 3 to 7 μπ \.

·; ··· Example 2. This dispersion was prepared by the method of Example 1 from the following components: ... 30287 g of water • 3 g of 20 g of polyvinylpyrrolidone K90 • a * ”· 18 g of phenolsulfonic acid / formaldehyde condensate 732 g of diisopropylnaphthalene 10 104794 314 g of high boiling aliphatic hydrocarbon mixture (boiling range 230-265 ° C) 48 g of a mixture of 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (36 g) and N-benzoyl-5 leukomethylene blue (12 g) 131 g of methyl methacrylate 5.6 g of butanediol diacrylate 1.4 g of azobisisobutyronitrile 2 g of dimethyl 2,2-azobisisobutyrate.

The resulting dispersion had a solids content of 48.5% by weight and a flow time from the Ford cup of 135 seconds.

The microcapsules had an average particle size of 5.4 μιη with a size range of practically 3 to 7 µm. Example 3 This dispersion was prepared by the method of Example 1 from the following components: 1280 g water 20 g polyvinylpyrrolidone K90 15 g phenolsulfonic acid / formaldehyde condensate 732 g diisopropylnaphthalene 314 g high boiling aliphatic hydrocarbon C) 48 g of a mixture of 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (36 g) and N-benzoyl leucomethylene blue (12 g) • 9 · 93.5 g methyl methacrylate 37 , 4 g butanediol acrylate · · · 1.4 g azobisisobutyronitrile ... 30 2 g dimethyl 2,2-azobisisobutyrate • ·

The dispersion obtained had a solids content of 48.6% by weight and a flow time from the Ford cup of 103 seconds.

The microcapsules had an average particle size of 5.8 μτη with a size range in the range of 3-8 μιη.

«« · 35 li 104794

Example 4 This dispersion was prepared by the method of Example 1 from the following components: 1270 g of water 5 15 g of polyvinylpyrrolidone K90 15 g of phenolsulfonic acid / formaldehyde condensate 636 g of diisopropylnaphthalene 273 g of high boiling aliphatic hydrocarbon ) 48 g of a mixture of 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (36 g) and N-benzoyl-leukomethylene blue (12 g) 287 g of methyl methacrylate 15 33 g of acetoacetoxyethyl methacrylate 5.5 g of azobisisobutyronitrile However, after 1.5 hours of polymerization at 60 ° C, 2,2-azobisisobutyrate was added a solution of 4.7 g of formaldehyde and 28 g of water in one hour, and the temperature was raised to 65 ° C and maintained at 1.5 ° C. hours.

The resulting dispersion had a solids content of 48.2% by weight and a flow time from the Ford cup of 74 seconds.

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The average particle size of the microcapsules was I «· i '. · 25 5.5 μτη with a practical size ranging from 3 to 8 μηι.

Example 5 *: · 1: This dispersion was prepared by the method of Example 1: 1 · 1; with the following components: 1280 g water ···. 3 0 20 g of polyvinylpyrrolidone K90 • · 15 g of phenolsulfonic acid / formaldehyde condensate • · · thia * · 1,522 g of diisopropylnaphthalene 522 g of dodecylbenzene «II · III · • · · 12 104794 48 g of 3.3- a mixture of bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (36 g) and N-benzoyl leukomethylene blue (12 g) 19 g ethyl acrylate 5 9 g ethyl methacrylate 19 g 2-ethylhexyl acrylate 112 g methyl methacrylate 2 g of dimethyl 2,2-azobisisobutyrate

The dispersion obtained had a solids content of 43.5% by weight and a flow time from the Ford cup of 106 seconds.

The microcapsules had an average particle size of 5.8 μηι, with a practical variation in the range of 3-12 μιη.

Example 6 This dispersion was prepared by the method of Example 1 from the following components: 1 464 g water 50 g polyvinylpyrrolidone K90 20 10 g polyacrylic acid K50 645 g diisopropylnaphthalene 285 g high boiling aliphatic hydrocarbon mixture (boiling range 230-265 ° C) 50 g of a mixture of 3,3-bis (p-dimethylaminophenyl) -6-dimethyl-25-yl-aminophthalide (35.5 g) and N-benzoyl leukomethylene blue (12.5 g) ·: ··· 120 g methyl methacrylate 2 g azobisisobutyronitrile 30 g 20% anhydrous methacrylate copolymer ... 30 dispersion in cyclohexane (methacrylic acid content 4.8%).

After heating to 65 ° C, the vessel was polymerized at this temperature for 2.5 hours and then at 70 ° C for 2.25 hours.

• 4 · «• · 13 104794

The dispersion obtained had a solids content of 41.6% by weight and a flow time from the Ford cup of 50 seconds.

The microcapsules had an average particle size of 5.2 μτη with a size range in the range of 2-6 μπι.

Example 7 This dispersion was prepared by the method of Example 6 from the following components: 1334 g water 45 g polyvinylpyrrolidone K90 10 11 g polyacrylic acid K50 732 g diisopropylnaphthalene 313 g high boiling aliphatic hydrocarbon mixture (boiling range 230-265 ° C) 55 g of a mixture of 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (41 g) and N-benzoyl leukomethylene blue (14 g) 187 g methyl methacrylate 3.1 g azobisisobutyronitrile 45 g 20% anhydrous methacrylate copolymer dispersion in cyclohexane (methacrylic acid content 4.8%)

The dispersion obtained had a solids content of 47% by weight and a flow time from the Ford cup of 106 seconds.

The microcapsules had a mean particle size of • · 4 l at 5.4 μτη with a practical variation in size between 3 and 6 μπι.

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The permeability, color intensity and abrasion sensitivity of the microcapsules of the present invention were examined.

In this case, the microcapsule dispersions were diluted to a solids content of 16.5% by weight and then applied in an amount of 5 g microcapsules per square meter (a) on standard typewriting paper and • ·:, * ·· b) typewriting paper that had been pretreated to develop color with attapulgite, and then these papers were dried.

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I · • <· 14 104794 Ά) Determining Permeability Permeability is a measure of the amount of color former in non-capsule form.

To determine the permeability, the paper b) was slightly moistened with dodecylbenzene, whereupon the non-encapsulated color former was detached and formed with the developer. The degree of discoloration of the paper so treated was measured by measuring the difference between the reflectances of the non-sprayed paper sheet b) and the sprayed sheet of paper b) by reflection photometry and reported as relative percentages by setting the reflectance of the un sprayed paper sheet b).

B) Determination of Color Intensity To determine the color intensity, the coated sheet of a) sheet of paper a) was placed against a paper coated with a color developer and three additional layers of 38 g / m 2 paper were placed on top. This stack of paper was then typed into an area of 4.2 x 3.4 cm with maximum compression. The color intensity of a Nel-20 stretch copy was measured by a reflection photometer as the difference of reflection between the typewritten paper and the unwritten paper and is expressed as relative percentages of the reflectance of the unwritten paper, defined as 100.

: 25 C) Determination of Abrasion Sensitivity: * ·. · The hue value is a measure of the color obtained by rubbing only.

To determine the abrasion value, a sheet of paper a) was placed over a sheet of • paper treated with a color developer and ... 30 papers a) pulled slowly and evenly with a flat flat weight of 2.1 N / cm2 loaded with a developer coated sheet. over the paper.

The developer-coated paper was then kept in the dark for an hour, and then its degree of staining was measured by a reflection photometer, whereby the difference between the reflectance values of the scratched and the tailed paper was calculated. as a percentage of the reflection value of uncoated paper set to 100.

The following table shows the results of tests A, B and C 5.

TABLE

Application Characteristics of Microcapsules of Examples 1-5 10 Pre-Permeation Color Intensity Rubbing Value (%) (%) (%) 1 43 29.8 23.7 2 7 38.8 15.5 3 10 42.0 19.8 15 4 43 23.3 15.3 5 27 28.5 38.5

Example 8

Mixture of 20 1 287 g of water 20 g of polyvinylpyrrolidone K90 18 g of phenolsulfonic acid-formaldehyde condensate 770 g of diisopropylnaphthalene • · * V 25 330 g of high boiling aliphatic hydrocarbon /. : thiose mixture (boiling range 230-265 ° C) *: ··· 48 g of 3,3-bis (p-dimethylaminophenyl) -6-dimer * £ *. of a mixture of methylaminophthalide (36 g) and N-benzoyl leukomethylene blue (12 g) 30 131 g of methyl methacrylate. 56 g of butanediol diacrylate • · 3.4 g of tert-butyl perpivalate t <I were treated as described in Example 1. It was polymerized at 51 ° C for 2 hours and then raised to 35 to 72 ° C for 4 hours.

16 104794

Example 9

A mixture of 1 293 g of water 20 g of polyvinylpyrrolidone K90 5 27 g of phenolsulfonic acid-formaldehyde condensate 770 g of diisopropylnaphthalene 330 g of a high boiling aliphatic hydrocarbon mixture (boiling range 230-265 ° C) 10 48 g a mixture of bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (36 g) and N-benzoyl leukomethylene blue (12 g) 131 g methyl methacrylate 56 g butanediol acrylate 15 1.4 g azobisisobutyronitrile in 1 g dimethyl 2,2-azobisisobutyrate 1 as described. It was polymerized at 65 ° C for 2 hours and then raised to 71 ° C for 4 hours.

Example 10

Mixture of 1 287 g of water 20 g of polyvinylpyrrolidone K90: 18 g of phenolsulfonic acid-formaldehyde condensate · 25 · 25. : 770 g of diisopropylnaphthalene »· 330 g of high boiling aliphatic hydrocarbon mixture (boiling range 230-265 ° C) II · * 48 g of 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (36 g) and a mixture of N-benzoyl -? - leukomethylene blue (12 g)

III

131 g of methyl methacrylate 56 g of butanediol acrylate 1.4 g of azobisisobutyronitrile • '35 2 g of dimethyl 2,2-azobisisobutyrate 17 104794 were treated as described in Example 1. It was polymerized at 60 ° C for 2 hours and then raised to 75 ° C for 4 hours.

Example 11 A mixture of 1287 g water 20 g polyvinylpyrrolidone K90 18 g phenolsulfonic acid formaldehyde condensate 10 l carboxymethylcellulose 770 g diisopropylnaphthalene 330 g high boiling aliphatic hydrocarbon (48 g) A mixture of 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (36 g) and N-benzoyl leukomethylene blue (12 g), 131 g of methyl methacrylate, 56 g of butanediol acrylate, 1.4 g of azobisisobutyronitrile, 20 g of dimethyl-2, 2-Azobisisobutyrate was treated as described in Example 1.

Example 12 t'j · Mixture containing: 1 287 g of water 25 20 g of polyvinylpyrrolidone K90. : 18 g of phenolsulfonic acid-formaldehyde condensate ♦ · ... 1.3 g of polyacrylic acid • ♦ ♦ * 770 g of diisopropylnaphthalene 30 330 g of high-boiling aliphatic hydrocarbon ··· ♦ mixture (boiling range 230 - 265 °) C) • · · · · · 48 g of a mixture of 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (36 g) and N-benzoyl-leucomethylene blue (12 g) 35 131 g of methyl methacrylate 104794 ° C 56 g Butanediol acrylate 1.4 g Azobisisobutyronitrile 2 g Dimethyl 2,2-azobisisobutyrate was treated as described in Example 1. It was polymerized at 60 ° C for 2 hours and then raised to 75 ° C for 4 hours.

Example 13 Mixture of 1287 g of water 10 20 g of polyvinylpyrrolidone K90 18 g of phenolsulfonic acid formaldehyde condensate 770 g of diisopropylnaphthalene 330 g of high boiling aliphatic hydrocarbon mixture (boiling range 230-265 ° C) A mixture of 3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (36 g) and N-benzoyl-leucomethylene blue (12 g) 131 g methyl methacrylate 20 56 g 1,3-propanediol acrylate 1.4 g azobisisobutyronitrile 2 g dimethyl-2,2 azobisisobutyrate II 'was treated as described in Example 1. It was polymerized at 60 ° C for 2 hours and then raised to 25 to 75 ° C for 4 hours,

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: Example 14

Mixture of kk ... 1 287 g of water • 20 g of polyvinylpyrrolidone K90 30 g of phenolsulfonic acid-formaldehyde condensate • 770 g of diisopropylnaphthalene 330 g of high boiling aliphatic hydrocarbon mixture (boiling range) 265 ° C) 19 104794 48 g of a mixture of 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (36 g) and N-benzoyl-leucomethylene blue (12 g) 131 g of methyl methacrylate 5 56 g of hexanediol acrylate 1.4 g of azobisisobutyronitrile 2 g of dimethyl 2,2-azobisisobutyrate were treated as described in Example 1. It was polymerized at 60 ° C for 2 hours and then raised to 10 to 75 ° C for 4 hours.

Example 15 Mixture of 1287 g of water 20 g of polyvinylpyrrolidone K90 15 18 g of phenolsulfonic acid-formaldehyde condensate 770 g of diisopropylnaphthalene 330 g of a high boiling aliphatic hydrocarbon mixture (boiling range 230-265 ° C) A mixture of 3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (36 g) and N-benzoyl-leucomethylene blue (12 g). * 131 g methyl methacrylate: 56 g butanediol acrylate · * · 5.4 g bis (3,5,5-trimethylhexanoyl) peroxide: treated as described in Example 1. It was polymerized at 52 ° C for 2 hours and then raised to • * ... 59 ° C for 4 hours.

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Example 16 30 Mixture of * ··· * 1287 g of water * ... · 20 g of polyvinylpyrrolidone K90 18 g of phenolsulfonic acid-formaldehyde condensate 35 1 g of carboxymethylcellulose 20 1 0 4 7 9 4 770 g of diisopropylnaphthalene 330 g of a high boiling aliphatic hydrocarbon mixture (boiling range 230-265 ° C) 48 g of a mixture of 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (36 g) and N-benzoyl leucomethylene blue (12 g) 131 g methyl methacrylate 56 g butanediol acrylate 1.4 g azobisisobutyronitrile 10 g dimethyl 2,2-azobisisobutyrate

With the exception of the monomers and initiators, all ingredients were dispersed together at room temperature for 5 minutes. The other ingredients were then added and the dispersion continued for another 15 minutes. The mixture was polymerized at 60 ° C for 2 hours and then at 65 ° C for 4 hours.

Example 17 Mixture of 128 g of water 2 g of polyvinylpyrrolidone K90 1.8 g of phenolsulfonic acid formaldehyde condensate 13.1 g of methyl methacrylate II * 5.6 g of butanediol acrylate: 88 g of di (2-ethylhexyl) phthalate 25 22 g perfume t <: 0.14 g of azobisisobutyronitrile • · · · m · m · 2 g of dimethyl 2,2-azobisisobutyrate • · ... All ingredients were dispersed together at room temperature for 3 minutes. At 2 ° C for 30 hours and then at 65 ° C for 4 hours The perfume-containing microcapsules had a diameter of 2-5 µτη.

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·, ,, · Example 18

Mixture of 128 g water 35 2 g polyvinylpyrrolidone K90 21 104794 1.8 g phenolsulfonic acid formaldehyde condensate 13.1 g methyl methacrylate 5.6 g butanediol acrylate 5 110 g metolachlor 0.14 g azobisisobutyronitrile 0.2 g 2-azobisisobutyrate

All ingredients were dispersed together at room temperature for 3 minutes. The mixture was polymerized at 60 ° C for 2 hours to 10 hours and then at 65 ° C for 4 hours. The microcapsules containing the plant protection agent had a diameter of 3-8 μτη. Example 19 A mixture of 128 g of water 15 g of polyvinylpyrrolidone K90 1.8 g of phenol sulfonic acid formaldehyde condensate 18.6 g of methyl methacrylate 88 g of lead (II) -2-ethylhexanoate 20 22 g of white oil 0.1 g of azobisisoburyronitrile g of dimethyl 2,2-azobisisobutyrate

All ingredients were dispersed together at room temperature for 5 minutes. The mixture was polymerized at 60 ° C for 2 hours and then 12 ° 3: 1: 25 then at 65 ° C for 4 hours. The micro-capsule containing lead salt • · .1 ·. ♦ had a diameter of 2-6 μπι.

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The microcapsules prepared in Examples 8-19 have similar characteristics to those produced in Examples 1-7.

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Claims (8)

22 1 0 4 7 9 4 Microcapsules, characterized in that they are obtained by polymerization Microcapsules according to claim 1, characterized in that they are obtained by polymerization A) 30-95% by weight of monomers I, B) 5-40% by weight of monomer II and C) 0-30% by weight of other monomers III. 1 ,,; ' Microcapsules according to claim 1, characterized in that the boiling point of the water-insoluble or slightly soluble solvent is 150 to 350 ° C. <<. • .J Microcapsules according to claim 1, characterized in that the water-insoluble or sparingly soluble solvent is diisopropylnaphthalene or dodecylbenzene. 5. A process for the preparation of microcapsules, characterized in that the water-insoluble or water-insoluble solvent is modified with or without the following ingredients: a) 30 to 100% by weight of one or more C: -24 alkyl esters of acrylic or 35-methacrylic acid (monomers I), 23 104794 B) 0-80% by weight of a bi- or polyfunctional monomer (monomer II) soluble in a solvent, and C) 0-40% by weight -% of other monomers (monomers III) and 5 free-radical initiator in water, conventionally in a stable oil-in-water emulsion, and then polymerization of the monomers is initiated and controlled by thermal decomposition of the free-radical initiator by raising the temperature of the shell and core to form capsules. A) from 30 to 100% by weight of one or more C1.24 alkyl esters of acrylic acid or methacrylic acid (monomers I), B) 0 to 80% by weight of a bi- or polyfunctional monomer (monomer II) which is soluble in a solvent which: insoluble or slightly soluble in water, and 10 C) 0 to 40% by weight of other monomers (monomers III), wherein the solvent is present alone or in combination with the monomers and the free radical initiator in a dispersed oil-in-water emulsion and polymerization is initiated; it is controlled in stages by the thermal decomposition of the free radical initiator by raising the temperature. Microcapsules according to claim 1, characterized in that they contain a color former. Use of the color forming microcapsules of claim 6 for the manufacture of a pressure sensitive recording material. 8. Pressure-sensitive recording material containing microcapsules according to claim 6, characterized in that it further contains a component for color development. • «· I • I • ♦ ♦ ♦ ♦ ♦ ♦ ♦ 1 1 1 1 1 1 1 1 1 24 1 0 4 7 9 4