DE2307247A1 - METHOD OF MANUFACTURING MICROCAPSULES - Google Patents

Description

The invention "relates to a process for the production of oil containing microcapsules which have a synthetic capsule wall with a high molecular weight.

Microcapsules containing oil are widely used in practice for pressure sensitive or self-adhesive Copy papers and will probably be used in the future Manufacture of medicines, agricultural chemicals., Perfumes and the like. Can be used extensively.

The capsule wall of the known, oil-containing microcapsules, however, has not yet been designed for practical use sufficient strength. One is accordingly v / oitcrhin on the "search for improved method for Hearst." production of oil-containing microcapsules.

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As a process for the production of oil containing microcapsules, "where a reactive substance is dissolved in an oil and the Substance is reacted with the formation of a cell film the following processes are known to have a high molecular weight :. . ■.

(a) ein.Verfahren in which a prepolymer of a resin with hydrophobic and hydrophilic groups in the molecule dissolved in an oil, -this so emulsified in a polar solvent becomes ,, that polymerizable. Molecular centers at "the water / Oil interfaces arise, and the polymerization on the outer surface of the oil droplets by adding a polymerization accelerator is carried out; - - ..

(b) a method in which an oil and an oil-soluble Substance that by polymerization forms a substance insoluble in oil, a solution is made, the solution-in a polar one Liquid emulsified and self-polynierizing the Substance capsule films are formed, (as a polymerisable substance if one with a double bond is used, such as ethyl acrylate, methyl acrylate, methyl methacrylate, ethyl methacrylate, Vinyl acetate, styrene and divinylbenzene); and

(c) a method used in the two mutually reactive substances, an added by them and the encapsulated oil and the other a continuous fiber ^r-forming polar liquid is added and then the two substances at the interface between the oil droplets and the continuous phase are reacted with one another to form a capsule film.

However, in the above-mentioned methods (a), (b) and (c) inside the oil droplets · only a single cell wall. forming substance. The methods (a) and (c) have the

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Disadvantage that the capsule film obtained thereby has poor pressure and friction resistance because the film-forming reaction proceeds only on the surface of the oil droplets. On the other hand, in the method (b) in which the capsule film consists of a formed by self-polymerization of a film-forming material having a double bond inside the oil droplets, oil-insoluble reaction products, the oil-insoluble reaction product is not only on the surface of the oil droplets but also formed in the interior of the oil droplets .. As a result, can not Mikroka / pseln with a coated surface with the reaction product _t but only oil containing spherical microcapsules are obtained, whose interior is filled with the reaction product.

In these microcapsules, because of the great permeability or permeability of the capsule film, the enclosed material penetrates Oil is released to the outside or is released to the outside when heated and as a result the trapped materials cannot be kept over a longer side space.

In addition, when such microcapsules are used, a reaction of one enclosed in the capsule can be used Substance with a substance outside the 'capsule to prevent this goal from being achieved -because those in the capsule Trapped substance reacts through the capsule film (the capsule wall) with the substance outside the capsule because the capsule film is permeable. This is a technical problem that needs to be improved, especially in use of the above-mentioned microcapsules in a pressure-sensitive Copy paper.

In particular, it occurs when a top sheet is made by dissolving a nearly colorless compound that results in a color reaction in an oil (color former), encapsulating the oil according to the previously known micro-encapsulation process and application dor capsules received on a carrier, on oin

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underlying paper made by applying a Developer substance (developer), which can form a color product by reacting with the color former, applied and with Water is wetted, the disadvantage that the color former in the microcapsules through passage durch.den capsule film into the The sheet underneath migrates, whereby a color veil is firmly detached. On the other hand, when an interleaf is used, it spreads out (middle sheet) in which a developer is applied to one surface of a support and microcapsules on the back thereof, the capsule solution through small openings in the carrier in the surface coated with the developer or penetrates into this, if according to the previously known Process manufactured "microcapsules used and according to applied to the application of the developer. Consequently there is a disadvantage that the commercial fourth of the pressure-sensitive copying paper is markedly deteriorated because the color former is in the capsule with the developer reacts to form a color and to form colored spots. In addition, in the production of a pressure-sensitive recording paper in which a developer and known microcapsules that contain a color former are applied to the same surface of the carrier, the disadvantage that the developer through the capsule film with the color former in the microcapsules reacts to form a color haze. ·

The aim of the present invention is therefore to provide an improved method for producing von.Mikrokapseln that against Pressure, friction and heat are very resistant and their walls has a very low permeability.

It has now been found that this aim according to the invention with a method can be achieved which consists in that in a polar liquid, which is a continuous phase, an oil (to be encapsulated in microcapsules)

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emulsifies a compound having a group capable of reacting with an active hydrogen group (hereinafter referred to as first, called a cell film or a capsule wall-forming substance) and a compound with an active hydrogen group contains j which is soluble in the oily liquid to be encapsulated (hereinafter referred to as the second, a cell film or a capsule wall-forming substance), which in the reaction with the first, capsule-wall-forming substance forms a compound with a high molecular weight, and the cell wall of the capsule produces by reacting the first substance forming a capsule wall with a compound with an active hydrogen group which (at least in part) is soluble in the polar liquid (hereinafter referred to as the third substance that forms a cell film or a capsule wall referred to) in the polar liquid on the surface of the Oil droplets in the same response system as the cell wall by reacting the first substance forming a capsule wall with the second substance forming a capsule wall is generated inside the oil droplets, the combination of the first, the second and the third, a capsule wall forming substance in a sufficient amount to form the capsule wall Amount is used.

The invention therefore relates to a method for production of microcapsules, which is characterized in that an oil to be encapsulated which contains a first, a capsule wall forming substance and a second substance which forms a "capsule wall", which by reaction with the first, a capsule wall forming substance forms a high molecular compound, eiaulgieri in a polar liquid as a continuous phase; and producing the microcapsules by reacting the first, a capsule wall-forming substance with a third, a ' Capsule wall-forming substance in a polar liquid on the surface of the oil droplets in the same in which the capsule walls by implementing the first, a

Capsule wall-forming substance are formed with the second, capsule-wall-forming substance inside the oil droplets ", with the formation of a stable capsule wall with a "low Permeability to the encapsulated content.

The components of the η system according to the invention are described below briefly described:

I._ First_e, _one_ Chapter_s £ lwand__bildend_e Substans_

(a) it contains at least one group capable of with an active hydrogen-containing compound too react;

(b) it is used for implementation when necessary an auxiliary solvent dissolved in the oily liquid;

(c) it may or may not be insoluble in the polar liquid be;

(d) it forms a capsule wall with the third Substance a reaction product insoluble in the oily liquid and in the polar liquid.

Bildj3nde_Subj3tanz

(a) it contains active hydrogen,

(b) see I .. (b),

(c) it is preferably insoluble in the polar liquid,

(d) It forms one in the oily liquid and in the polar liquid with the first substance which forms a capsule wall Liquid insoluble reaction product.

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IIJ._third, _a cheesecloth__TDildend_e substance_

(a) it contains alcaline hydrogen,

(b) it is at least partially in the polar liquid soluble,

(c) it may or may not be in the polar liquid be insoluble and

(d) see I. (d). .

According to the above-mentioned, a capsule wall forming substances are added after emulsifying the oil of the polar liquid or an oil that is the first, a Capsule wall-forming substance and the second substance, capsule-wall-forming substance, may be in the polar liquid which contains the third substance which forms a capsule wall.

The method, which consists in first mixing the first, capsule wall-forming substance with the second, a capsule wall forming substance in the oil to be encapsulated, this oil is emulsified and then the third, a capsule wall forming substance on the surface of the oil droplet is reacted with it to form a capsule film, seems to be the invention. to be similar to the method according to the invention, but it is essentially different from this in technical terms and the Resistance of the capsules to pressure and friction is much lower than that of the method according to the invention manufactured capsules. According to the method according to the invention The microcapsules produced not only have very good resistance to pressure and friction and good heat resistance on, but their capsule wall also has a very low permeability or permeability. About that In addition, emulsification can be carried out according to the process according to the invention

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can be carried out easily and capsules of uniform size can easily be manufactured.

As can be seen from the foregoing, it was according to the invention Process by no combination of the "previously known processes for the production of microcapsules suggested"

The first and second capsule wall-forming substances used in the method according to the invention are are compounds that react with each other in the oil, one in both the oil and the polar liquid form insoluble compound with a high molecular weight. The third substance, which forms a capsule wall, acts it is a compound that is dissolved or dispersed in the polar liquid (which is a continuous phase) and by reacting with the first capsule wall-forming substance in both the oil and the polar liquid forms insoluble substance with a high molecular weight. '-

Preferred examples of the first capsule wall-forming substance used in the present invention are compounds with two or more isocyanate groups, isothiocyanate groups, Epoxy groups, acid chloride groups, chloroformate or lilpichlorohydrin groups. Preferred examples of the second capsule wall-forming substance used in the present invention are are compounds with two or more hydroxyl groups, carboxyl groups, Mercapto groups, amino groups and the like. Preferred examples of the third capsule wall-forming substance, which is used according to the invention are compounds with two or more amino groups, hydroxyl groups, carboxyl groups, Mercapto groups or alkali metal salts of aromatic polyhydroxy compounds O "

Examples of preferred combinations of these substances are given in Table I below.

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Combination system

label I

the first, a capsule wall forming the second, a capsule wall forming the third, a capsule wall Substance forming substance forming substance

Polyisocyanates, polyisocyanate polyhydroxy compounds,

addition products with residual epoxy compounds, polycarbon small isocyanate groups ^ polyisodium acids, polythiols (mercapto

cyanates or polyisothiocyanate compounds) and phenol form

addition products with residual aldehyde resins chen isothiocyanate groups and epichlorohydrin polyamines or modified Products thereof, polyhydroxy compounds, polycarboxylic acids and Polythiols

Epoxy compounds polyamines or modified
Products thereof

Polyamines or modified products thereof

CO O -3 K)

polybasic acid chlorides and polyvalent chloroformates Phenol-formaldehyde resins, polyhydroxy compounds, polythiols and polycarboxylic acids

Polyamines or modifi- ' decorated products thereof,, alkali metal salts of phenol-formaldehyde condensates and alkali metal salts of aromatic polyhydroxy compounds

of the combination system are the first, the second and the third, forming a capsule wall Substance different from each other.

The capsule wall-forming substances used in the above combinations are not intended to limit the invention in any way, that is, the capsule-wall-forming substances added to the oil to be encapsulated are not always limited to two types, but more than two types thereof can be used. For example, it is possible to use a capsule wall-forming substance B ¹ that reacts with a capsule-wall-forming substance A. together with two kinds of capsule-wall-forming substances A and B that react with each other. In addition, two kinds of capsule wall forming substances A 'and B' which react with each other can be used together with two kinds of capsule wall forming substances A and B which react with each other.

In addition, as a third substance, which forms a capsule wall, the polar liquid forming a continuous phase is present, two or more substances are used, those with at least one of the oils contained in the oil to be encapsulated, substances forming a capsule wall react and become insoluble in both the oil and the polar liquid Form substance. , ·

Examples of polyisocyanates and polyisocyanate addition products containing an isocyanate group are aliphatic or aromatic compounds, such as e.g. the diisocyanates and diisothiocyanates, for example m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, naphthalene-1,4-diisocyanate,. Diphenylmethane-4,4'-diisocyanate ^s 'dimethoxy-4,4'-biphenyl diisocyanate, 3,3, 3 s 3'-Dimethyldiphenylmethan-4,4'-diisocyanate, xylylene diisocyanate, 1,4-xylylene-1 , 3-diisocyanate, 4,4'-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, ethylidine diisocyanate, cyclohexylene

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1,2-diisocyanate, cyclohexylene-1,4-diisocyanate, xylylene-1,4-diisothiocyanate, ethylidine diisothiocyanate and hexaniethylene diisothiocyanate; Triisocyanates such as 4,4'-4 "-triphenylmethane triisocyanate, toluene-2,4,6-triisocyanate and polyethylene polyphenyl isocyanate; tetraisocyanates, such as 4,4'-dimethyl-diphenylmethane-2,2 ¹ , ^ j ^ '- tetraisocyanate, and addition products having two or more isocyanate groups in the molecule, which are produced by adding the above-mentioned polyisocyanates to polyamines, polycarboxylic acids, polythiols, polyhydroxy compounds, epoxy compounds and the like.

Examples of epoxy compounds are aliphatic glycidyl ethers, of which the preferred aliphatic groups contain 3 to 18 carbon atoms, such as diglycidyl ether, glycerol triglycidyl ether and polyallyl glycidyl ether; aliphatic glycidyl esters, like the diglycidyl ester of dimeric linoleic acid; aromatic glycidyl ethers such as the diglycidyl ether of bisphenol A, the triglycidyl ether of trihydroxyphenylpropane and the Tetraglycidyl ether of tetraphenylenathane; and glycidyl ethers estermi loops, like the digylcidyl ether ester of 4,4-bis (4-hydroxyphenyl) pentanoic acid.

Examples of polybasic acid chlorides are aliphatic (preferably with 3 to 18 carbon atoms in the aliphatic Group) and aromatic (preferably with 1 or 2 aromatic units) polycarboxylic acid chlorides, such as adipic acid chloride, Sebacoyl chloride, phthaloyl chloride, terephthaloyl chloride, Hydro: cypolyamine and the like.

Examples of polychloroformates are compounds in which at least two chloroformate groups are linked to one another via an aliphatic or aromatic hydrocarbon, such as hexamethylene bis (chloroformate), p-phenylene bis (chloroformate), ClOCO- ^ A-OOOGl and the like.

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Examples of polyhydroxy compounds are aliphatic and aromatic polyhydroxy compounds, hydroxy polyesters and hydroxy polyalkylene ethers and the like. Examples of aromatic and aliphatic polyhydroxy alcohols that can be used are catechol, resorcinol, hydroquinone, 1,2-dihydroxy-4-methylbenzene, 1,3-dihydroxy-3-methylbenzene , 4-dihydroxy-1-methylbenzene, 3 ₅ 5 ~ I) i-hydroxy-1-methyrbenzene, 2,4-dihydroxyethylbenzene, 1,3-naphthalenediol, 1,5-faphthalenediol, 2,7-naphthalenediol, 2,3 -Naphthalene diol, o, o'-biphenol, ρ, ρ'-biphenol, 1,1'-bi-2-naphthol, bis-phenol A, 2,2'-bis- (4 * hydroxyphenyl) butane, 2.2 '-Bis- (4-hydroxyphenyl) -isopentane, 1,1'-bis- (4-hydroxyphenyl) -cyclopentane, 1,1'-bis- (4-hydroxyphenyl) -cyclohexane, 2,2'-BiS- ( 4-hydroxy-3-methylphenyl) propane, bis (2-hydroxyphenyl) methane, xylene diol, ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 1,6-heptanediol , 1,7-heptanediol, 1,8-octanediol, 1,1,1-trimethylolpropane, hexanetriol, pentaerythritol, glycerin and sorbitol.

Examples of usable hydroxy polyesters are those made from polycarboxylic acids and polyhydroxy alcohols. Examples for polycarboxylic acids for the production of hydroxypolyesters are aliphatic polycarboxylic acids such as malonic acid, succinic acid, Glutaric acid, adipic acid, gluconic acid, pimelic acid, maleic acid and the like, or aromatic polycarboxylic acids, such as isophthalic acid and terephthalic acid. The above-mentioned compounds can be used as polyhydroxy alcohols.

Examples of hydroxypolyalkylene ethers are the condensation products of alkylene oxides and polyhydroxy alcohols. As alkylene oxides butylene oxide, amylene oxide, propylene oxide and ethylene oxide can be used to produce the hydroxypolyalkylene ethers will. The above-mentioned compounds can be used as polyhydroxy alcohols (e.g. the adducts of sorbitol or Trimethylol with propylene oxide or ethylene oxide, such as ACTCOL XS-550 B (trade name for an adduct of sorbitol with propylene

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oxide from Takeda Chemical Industries Ltd », OH number 550, Viscosity 5500 cP) and HEvVPOL GEP 2800 (trade name for an adduct of trimethylol with ethylene oxide and propylene oxide, average molecular weight 2800)).

Examples of polycarboxylic acids are aliphatic ^ polycarboxylic acids such as pimelic acid, suberic acid, azelaic acid and sebacic acid, aromatic polycarboxylic ^{acids such as phthalic acid, terephthalic acid, 4,4 l} -biphenyl-bicarboxylic acid and 4,4'-sulfonyldibenzoic acid.

Examples of Polythiol® are the co nde nsation products of Thioglycol and the reaction products of polyhydroxy alcohols with suitable thioether glycols.

Examples of hydroxypolyamines are the adducts of a polyamine with an alkylene oxide such as AGTGOL XR 45 (trade name for a Adduct of ethylamine with propylene oxide from Takeda Chemical Industries Ltd., OH number 500, viscosity 55OÜ cP) and ACTCOL XGE 48B (trade name for an adduct of an aromatic Amine with propylene oxide from Takeda Chemical Industries Ltd., OH number 360, viscosity 30,000 cP).

Examples of polyamines or modified products thereof are aromatic polyamines such as o-phenylenediamine, p-phenylenediamine and diaminonaphthalene, aliphatic polyamines, such as 1,3 ~ propylenediamine, Diethylenetriamine and 1,6-hexamethylenediamine and addition products of aromatic and aliphatic polyamines and epoxy compounds. Connections with a large number of amino groups in the molecule such as gelatin can also be used. When a compound has two or more amino groups contains in the molecule, it can be used as a polyamine or as a polyamine-modified product in the process according to the invention be used.

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Examples of alkali metal salts which can be used according to the invention; ..; .-: of aromatic polyhydroxy compounds are the sodium al ζ .. of bisphenol A, the potassium salt of a phenol-formalin condensate, the alkali salts of 2,2'-bis- (4-hydroxyphenylpropane) , the alkali salts of Λ , 5-dihydroxynaphthalene and the alkali salts of phenophthalein.

The third capsule wall forming substance may be added after emulsifying the oil to be encapsulated containing the first and second capsule wall forming substances in the polar liquid or before emulsifying the polar liquid. However, it is preferably added after emulsification because emulsification can be carried out easily and because capsules have. uniform droplet size can be easily obtained because the oil droplets do not aggregate when emulsified and the ;. The viscosity of the emulsion does not increase rapidly. The oils which can be used according to the invention are liquids which are immiscible with water, such as vegetable oils, animal oils, mineral oils and synthetic oils. In general, without any limitation as to the other properties and / or types, any oil which meets this criterion can be used. Specific examples of such oils are paraffin oil, cottonseed oil, soybean oil, corn oil, olive oil, castor oil, fish oil ₉ lard, chlorinated paraffins, chlorinated diphenyls, dibutyl phthalate, dioctyl phthalate, tributyl phosphate, tricresyl phosphate, dibutyl malethol, benzyl alcohol, o-dichlorobenzene, typically benzyl Example of a polar. The liquid that forms a continuous phase is water, but butethylene glycol, glycerine, butyl alcohol, octyl alcohol and the like can also be used. The polar liquid used according to the invention is immiscible with the oil to be encapsulated.

For emulsifying the above-mentioned oil in the polar liquid, protective colloids or surface active agents can be used in

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an amount of preferably 2 "to 20% by weight or of 0.05 up to 1% by weight, based on the polar liquid used, be used. Examples of usable protective colloids are found in the Matur and synthetic hydrophilic ones High molecular weight substances such as gelatin, gum arabic, casein, carboxymethyl cellulose, starch, polyvinyl alcohol and the like. Examples of surfactants are anionic surfactants such as alkylbenzenesulfonates, Alkylnaphthalene sulphonates, polyoxyethylene sulphates and Turkish red oil and the non-ionic surfactants, such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenol ethers. and sorbitan fatty acid esters.

To speed up the implementation between the the capsule wall Forming substances, catalysts can be used. The catalyst can be used in a small amount (i.e. in a usually catalytic amount used) either to the oil to be encapsulated or to the polar liquid, which is a continuous Phase forms, are added. With the use of the catalyst, the capsule wall formation reaction proceeds more efficiently and it is possible to thereby further reduce the permeability of the capsule wall and that required to form the capsule wall Shorten time. In addition, if a catalyst is used, it is possible to carry out the encapsulation at a lower one Temperature.

Examples of catalysts that can be used are those catalysts "which is an addition reaction with an isocyanate group promote, such as amines, organic metal compounds, metal salts of organic acids and tertiary phosphine, which are preferred are used when the first substance forming a capsule wall is polyisocyanates or containing an isocyanate group Polyisocyanate addition products can be used.

Examples of amines which can be used as a catalyst in accordance with the invention

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.sind trialkylamines, such as triethylamine, tetraalkyldiamines, such as N ₅ N ₅ N ', N ¹ -tetramethyl-1, J-butanediamine, amino alcohols, such as dimethylethanolamine, ethoxylamine, ethoxyldiamine, esteramines, such as bis (diethylethanolamine) adipate, triethylenediamine, N ₅ N-dimethylcyclohexylamine derivatives, morpholine derivatives, such as N-methylmorpholine, and piperazine derivatives, such as N, N ¹ -diethyl-2-methylpiperazine and N, N'-bis (2-hydroxypropyl) -2-methylpiperazine.

Examples of organic metal compounds which can be used according to the invention are organic complex compounds that act as the metal center tin, lead, cadmium, cobalt, aluminum, potassium, chromium or contain zinc. The most preferred organic tin complex compounds are, for example, dibutyltin laurate and dibutyltin (- "2- / ethylhexoate).

Examples of metal salts of organic acids are the metal salts, such as the tin, lead, cadmium, cobalt, aluminum, potassium, chromium and zinc salts of oleic acid, naphthenic acid, Caproic acid, and octylic acid. Examples of tin salts of organic Acids belonging to these compounds are tin (II) oleate, tin 2-ethylcaproate, tin naphthenate and tin octylate.

Examples of tertiary phosphines are trialkylphosphines and Dialkylbenzylphosphines (those with alkyl groups, lower alkyl groups such as ethyl and butyl groups are preferred). These Catalysts can be used alone, but several types of catalyst can also be used together. Particularly good results are obtained when amines are combined with organic metal compounds or metal salts of organic Acids are used.

To speed up the implementation of the first one, a capsule wall forming substance and the second, a capsule wall

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"forming substance as well as the implementation between the first, a capsule wall-forming substance and the third, capsule-wall-forming substance, the system can be heated, however, the temperature of the system must be lower than the boiling point of the polar liquid which is the continuous Phase forms, or as the boiling point of the oil to be encapsulated. In general, a temperature of room temperature will be used used until just below the boiling point of the liquid.

The reaction time and the reaction pressure can vary widely within the temperature range given above For example, the pressure is typically atmospheric as in the examples given below, if there is no need to use underprinting or overprinting exists, and the reaction is only continued until it has ended, the reaction time being for example a few seconds to a day, depending on the selected reactants and the temperature used.

The oil-containing prepared by the process according to the invention Microcapsules have capsule walls with a very high strength and low permeability on. Accordingly, they give good results when used in a pressure-sensitive copier paper. The after microcapsules produced by the process according to the invention have the advantage that no color fogging occurs when the developer is used during the manufacture of a pressure-sensitive Copy paper comes into contact with a capsule solution because the permeability of the capsule film is very low. Such microcapsules also have the advantage that they are very qualitative high quality products can be produced because during the production of an intermediate paper (middle paper) or of a pressure-sensitive recording paper in which the

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Color former containing microcapsules and the developer are applied to the same surface, no color fogging occurs.

If the microcapsules produced according to the invention are a perfume oil is added, the perfume component does not penetrate through the capsule walls and is retained for a long period of time.

If the first and second capsule wall-forming substances are insoluble in the oil to be encapsulated, this may occur Oil solvents, such as acetone, tetrahydrofuran, methyl ethyl ketone and ethyl acetate, are added as auxiliary solvents, which dissolves the substances forming the capsule wall and is miscible with the oily liquid to be encapsulated »the auxiliary solvent can be used in an amount of less than 50% by weight, but of more than 0% by weight, usually less than 10% by weight, based on the oil, can be used.

The invention is illustrated in more detail by the following examples, but without being limited to it.

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example 1

7 g KOLONATE HL (a hexamethylene diisocyanate trimethylolpropane addition product containing isocyanate groups, Molar ratio 3: 1, made by Nippon Polyurethane Industry Co., Ltd.) as the first substance to form a capsule wall "and 1 g of ACTCOL 51-530 (a polyoxypropylene polyol, viscosity 28,000 cP, made by Takeda Chemical Industries, Ltd.) as the second, a capsule wall constituent substance was added to dipropylnaphthalene as 30 g added to the oil to be encapsulated. After dissolving, 1 g of dibutyltin laurate was added.

This oil became 60 g of water at 20 ° C., which contained 2 g (2% by weight) Carboxymethyl cellulose (viscosity 10-20 cP at 25 ° C, etherification number about 0.7) and 2 g of polyvinyl alcohol (average polymerization 550, saponification number 88 mol%), added with stirring to form oil droplets 4-10 microns in diameter. The system was then added diluted by 80 g of water. The third substance forming a capsule wall was water, which is the continuous phase formed, 6 g Epon hardener (EPICURE U) (an aliphatic polyamine-epoxy compound addition product (polyamino compound), Viscosity 60-120 Gardner-Holdt at 23 ° C., nitrogen of the amine: 18-21%, from Shell Chemical Co.). The temperature the system was kept so that it did not exceed 20 ° C during the above-mentioned operation. Then the The temperature of the system is increased to 85 ° C for 6 hours to allow the reaction between the first substance to form a capsule wall and the second capsule wall forming substance and the reaction between the first capsule wall forming substance To accelerate the substance and the third substance, which forms a capsule wall, to complete the encapsulation. on In this way, microcapsules containing BLOropylnaphthalene, which were surrounded by a capsule wall.

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According to the method described above, were also according to the invention Microcapsules made using ACTCOL IR 45 (an ethylenediamine-propylene oxide addition product, OH number 500, viscosity 5500 cP from Takeda Chemical Industries, Ltd.) instead of ACTCOL 51-530. ■

On the other hand, the above mentioned first, a capsule wall forming substance and the above-mentioned second capsule wall forming substance dissolved in dipropylnaphthalene. After the addition of dibutyltin laurate as a catalyst, the solution was heated to 65 ° C for 3 hours to produce the first, one 'To react capsule wall-forming substance with the second, capsule-wall-forming substance. In this case the viscosity increased of the dipropylnaphthalene oil to be encapsulated noticeably and the oil solidified to a semi-solid substance. This oil was in water containing carboxymethyl cellulose and polyvinyl alcohol, as emulsified in the first attempt. In this case emulsification was impossible because the first substance, which forms a capsule wall, reacted with the second, a capsule wall forming substance a substance had already arisen,

which was insoluble in the oil.

Example 2

In the same manner as in Example 1, an ear builder solution was prepared containing microcapsule! for a pressure-sensitive (self-adhesive) recording paper made with a very strong cellular film with impermeability properties were coated, but this time using a 1.5 g dissolved crystal violet lactone and 0.5 g of dissolved benzoylleucomethylene blue as a color former containing dipropylnaphthalene solution instead of 30 g of dipropylnaphthalene. This capsule solution was applied to a paper and dried to form an upper pressure-sensitive recording sheet. In this

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upper blade occurred after ten hours of heating to 10O ⁰ C no permeation of the contents, and there was no deterioration of the coloring ability observed in a conventional pressure-sensitive recording sheet lower.

In addition, one of 30 parts of water was placed on this top sheet, 100 parts of acid clay and 20 parts of SBR latex were applied and dried to form one pressure-sensitive recording sheet which was self-writing. This white sheet did not discolor. No color fog was observed when the surface was rubbed with paper and the like when writing on the same however, clear blue images were obtained. Similar results were obtained when using ACTCOL IR 45 instead of ACTCOL 51-530.

Comparative tests (A) and (B) were carried out as follows:

(A) Encapsulation was carried out using only one a capsule wall formation reaction inside the oil droplet with COLONATE HL as the first substance to form a capsule wall and ACTCOL 51-530 as the second substance to form a capsule wall Substance. In this example, no Epon hardener Epicure U was used as the third substance that forms a capsule wall. in the 7 g of COLONATE HL and 1 g of ACTCOL 51-530 were individually added to 32 g of a dipropylnaphthaic solution, which were used as color former for the pressure-sensitive recording paper contained 1.5 g of crystal violet lactone and 0.5 g of benzoyl leucomethylene blue. After dissolving, 1 g of dibutyltin laurate was added as a catalyst. This oily liquid became with vigorous stirring added to 60 g of water at 20 ° C. containing 2 g of carboxymethyl cellulose and 2 g of polyvinyl alcohol. After manufacture of oil droplets with a diameter of 4-10 microns became the

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Solution diluted by adding 80 g of water. The temperature the system was kept so that it did not exceed 20 ° C during the above-mentioned operation. To speed up After the reaction, the temperature of the system was raised to 85 C and the encapsulation was completed.

The capsule wall of the microcapsules contained in this way had a very high permeability, i. in the case of a pressure-sensitive upper recording sheet which was prepared by applying this capsule solution to a paper and drying the same, the capsule contents leaked -The capsules ran out and the staining ability of the upper sheet went down in a conventional pressure-sensitive lower recording sheet lost. In addition, the above developing solution was applied to a pressure-sensitive upper recording sheet applied, which was coated with this capsule solution, and dried to form a pressure-sensitive recording sheet which is self-writing. was. This sheet stained with the time blue even without lettering and it could therefore not be used in practice.

(B): Encapsulation was carried out using only one a capsule wall formation reaction on the outside of the oil droplets using COLONATE HL as the first, a Substance forming a capsule wall and an Epon hardener U as the third substance forming a capsule wall, i.e. without use the second, a capsule wall-forming substance according to Example 2. Specifically, 7 g of COLONATE HL to 32 g of a Dipropylnaphthalene solution was added, which used as a color former for the pressure-sensitive recording paper 1.5 crystal violet lactone and 0.5 g of benzoyl leucomethylene blue. Then the The solution is added with vigorous stirring to 60 g of water at 20 ° C., the 2 g of dissolved carboxymethyl cellulose and 2 g of dissolved polyvinyl alcohol contained. After making oil droplets

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with a diameter of 4-10 microns, the system was diluted by adding 80 g of water and adding to the water containing the continuous phase, 6 g Epon hardener U were added. The temperature of the system was kept so that it was not above 20 ° C. during this process. To speed up After the capsule wall formation reaction, the temperature of the system was increased to -85 ° C to complete the encapsulation. The microcapsules obtained in this way had poor resistance to pressure and friction. A pressure sensitive one Upper recording sheet made by applying this capsule solution to paper and drying was placed under a developer sheet prepared by applying the above-mentioned developing solution and drying had been to the developer layer with the capsule layer to bring in contact. Then the developer sheet became

shifted 15 cm under a pressure of 100 g / cm, with blue spots of color on the developer sheet due to the friction developed. The degree of discoloration (color staining) was very high compared to the color staining that occurred on the was formed in the same manner using a pressure-sensitive upper recording sheet made according to the present invention Procedure as in Example 2 was prepared. In addition, the above-mentioned developing solution was applied to this The upper sheet was applied and dried to form a pressure-sensitive recording sheet which was self-writing. A blue haze appeared on this sheet not only when writing under pressure, but also when the surface was rubbed with paper and the like, and it was therefore difficult to handle.

Example 3

5 g of TAKENATE D-103 were added to 20 g of dimethyldiphenylmethane as an oil (a tolylene diisocyanate-Ü? rimethyIo! propane addition product,

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Molar ratio 3: 1, with remaining isocyanate groups and 25% ethyl acetate from Takeda Chemical Industry Ltd.) was added as a substance that forms a capsule wall. To complete 7 g of acetone were added to the dissolution of the substances forming a capsule wall in the oil. To this oily Liquid was added as the second substance forming a capsule wall, 2 g of TAKELAC U-25 (a polyester polyol). These Oily liquid was added to 60 g of water at 18 ° C. with vigorous stirring, 3 drops of Turkish red oil and 3 g of gum arabic and 2 g of polyvinyl alcohol dissolved therein. After making oil droplets with a diameter of 5-20 Micron, the system was diluted by adding 100 g of water. As a third substance forming a capsule wall, 3 g Eponhärter U and 2 g EPOMATE QX-3 (a hardener for Epoxy resins, a polyamine-modified product with a viscosity of 20 P at 20 ° C, one active hydrogen equivalent von 85, the company Ajino.moto Co. Ltd.) was added. The temperature the system was kept during the above-mentioned operations so that it was not above 20 ° C. The system was -. Stirred one day and night at room temperature to complete encapsulation. Microcapsules were obtained the dimethyldiphenylmethane in a strong capsule wall , included. ,

Example 4

One drop of Turkish red oil, 1 g of carboxymethyl cellulose as used in Example 1 and 2 g of polyvinyl alcohol as used in Example 1 were dissolved in 80 g of water. As a third, a capsule wall-forming substance further 2 g EPOMATE N were 002 (a hardener for epoxy resin, a polyamine-modified product having a viscosity of 20 P at 20 ⁰ C, an active hydrogen equivalence of 85, the company Ajinomoto Co., Ltd. ) added and dissolved in the system.

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35 g of dipropynaphthalene were added to this aqueous solution (as oil), the 7 g TAKENATE D-I2ON (a bicyclohexylmethane diisocyanate-iD Rimethylolpropane addition product, molar ratio 3: 1, with remaining isocyanate groups, isocyanate group content 11.3%, from Takeda Chemical Industry, Ltd.) contained 2 g of Epon hardener as the first substance to form a "capsule wall" 828 (an epoxy compound with a viscosity of 25 ° C from 120 to 150 P, an epoxy equivalent of 184-194, molecular weight 380, from Shell Chem. Co.) and 10 g Perfume oil AROMA ORANGE (from Ogawa Kogyo Co.) under strong Stir added to form oil droplets 20-50 microns in diameter. The temperature of the system was kept during the above operations so that it was not above 20 ° C. There were 100 g of water from 20 ° C added to the system. The temperature of the system was raised to 50 ° C and the system was stirred for three hours, to complete the encapsulation. In this way, microcapsules containing perfume oil were obtained.

The capsule solution obtained was applied to paper and dried. If you keep the coated paper for 6 months Left room temperature, the AROMA ORANGE content did not evaporate from the capsules and the capsules only gave one strong orange-like odor when destroyed by pressure.

Example 5

6 g Epon Hardener 828 (an epoxy resin for coatings from Shell Chem. Co.) as the first substance to form a capsule wall was dissolved in 20 g of toluene. To this toluene solution were the second, a substance forming the capsule wall 2 g of o-phenylenediamine were added. This oily liquid became too much with vigorous stirring 50 g water, the 2 g gelatine and 3 g polyvinyl alcohol in

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contained dissolved form, added with the formation of oil droplets 60-100 microns in diameter. This operation was carried out at a temperature not above 15 ° C. to 6 g of diethylenetriamine were added to this continuous phase as the third substance forming a capsule wall. Around To accelerate the reaction to form the capsule wall, the temperature of the system was increased to 85 ° C. The system was stirred for a whole day and night to complete the encapsulation. That way were Microcapsules containing toluene are obtained. The.microcapsules were separated by filtration and dried by allowing them to stand at room temperature. The walls of the microcapsules had a very high mechanical strength and the capsules were not destroyed during filtration. Also meadows the capsules exhibited excellent thermal strength, and the toluene trapped therein occurred even after ten hours Do not heat up to 100 ° C.

Example 6

7 g of tolylene diisocyanate and 1 g of terephthalic acid chloride were added as the first substance forming a capsule wall to 25 g of xylene as an oil to be encapsulated. To this oily liquid, 2 g of 4,4'-biphenyldicarboxylic acid was added as a second substance forming a capsule wall. To completely dissolve these capsule wall-forming substances, 7 g of tetrahydrofuran was added to the oily liquid with stirring. The above operation was carried out at a temperature not higher than 10 ^° C. The oily liquid was added with vigorous stirring to 60 g of water containing 2 g of polyvinyl alcohol and 2 g of carboxydimethyl cellulose at a temperature below 10 ° C. in order to emulsify the system. After adding 100 g of water at 10 ° C to this system, the third substance forming a capsule wall was 4 g of thioglycol and 3 g of the sodium salt of a phenol-ebrmaline pre-addition

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Product added. The temperature of the system was increased to 80 ° C. This temperature became a whole day and a whole Maintain stirring overnight — keep to encapsulation complete. Thus, a microcapsule solution containing xylene was obtained.

Example 7

3 g Epicote 828, 3 g ACTCOL 51-530 and 6 g TAKENATE D-103 (a tolylene diisocyanate / trimethylolpropane addition compound with a molar ratio of 3: 1) was used as a capsule wall-forming substance to 30 g of dipropylnaphthalene as a substance to be encapsulated oil (the 10 g Perfume Oil Ibse from Ogawa Kogyo Co) was added. To complete the dissolution of these capsule wall-forming substances, 7 g Acetone added. In this case, the combinations of the substances forming the capsule wall consisted of D-103 and Epicote 828 and D-103 and ACTCOL 51-530, the inside of the oil droplet reacted with each other. This oily liquid was added to 50 g of water, which contained 3 g of polyvinyl alcohol, with vigorous stirring and contained 2 g of carboxymethyl cellulose. After making the oil droplets with a diameter of 5-10 μ the system was diluted by adding 100 g of water. The third to this aqueous system was a capsule wall forming substance 4 g of Epon hardener and 3 g of ACTCOL 51-530 were added. In this case, the ACTCOL 51-530 with the D-103 and the Epon hardener ü''with Epicote 528 and D-103 implemented on the surface of the oil droplets to form the cell film. The above operations were performed at one temperature carried out below 20 ° C. To accelerate the conversion between the substances forming the capsule wall the system then heated to 70 ° C and stirred for 3 hours to complete encapsulation. In this way became a Obtained microcapsule solution containing perfume oil. After the above

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Procedures were also made using ACTCOL IR-45 instead obtained from ACTCOL 51-530 microcapsules according to the invention.

This capsule solution was applied to paper and dried to form a sheet that was coated with the microcapsules containing the perfume oil. This capsule sheet was very resistant to pressure and friction, and the perfume odor was hardly noticeable during handling because the capsules were not destroyed. When this sheet was ^{heated to 100 °} C. for 10 hours or left to stand at room temperature for 12 months, the enclosed perfume did not escape through the capsule walls. When the capsules were broken by the application of pressure or friction, a strong fcosen-like odor was given off.

Although the invention has been explained in more detail above with reference to specific embodiments, it is it is clear to the person skilled in the art that these can be changed and modified in many ways without thereby affecting the Is left within the scope of the present invention.

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Claims (10)

PATENT CLAIMS 1. A method for the production of microcapsules, characterized in that an oil to be encapsulated which contains a first substance which forms a capsule wall and a second substance which forms a capsule wall which is produced by reaction with the first substance which forms a capsule wall forms a high molecular compound, emulsified in a polar liquid as a continuous phase and the microcapsules / »created by reacting the first, a capsule wall-forming substance with a third, a Capsule wall-forming substance in a polar liquid on the surface of the oil droplets in the same reaction system, in which the capsule walls by reacting the first, a capsule wall-forming substance with the second, a The substance forming the capsule wall is formed inside the oil droplets, with the formation of a stable capsule .wall with a low permeability for the encapsulated Contents. 2. The method according to claim 1, characterized in that the products of the reaction between the first and second, a capsule wall-forming substance and the first and third, substances forming a capsule wall in which oil and polar liquid are insoluble. 3. The method according to claim 1 and / or 2, characterized in that the first substance forming a capsule wall is a that is used which contains at least one group associated with an active hydrogen-containing compound can react under the reaction conditions, and that as the second and third substances forming a capsule wall 309834/09 10 those used are each active hydrogen contain. 4. The method according to at least one of claims 1 to 3, characterized in that a compound is used as the 'first substance forming a capsule wall, the two or more isocyanate, isothioeyanate, epoxy, acid chloride, chloroformate or epichlorohydrin includes groups that a compound is used as a second, a capsule wall-forming substance containing two or more hydroxy, carboxyl, mercapto or amino groups _s and that as a third, a capsule wall-forming substance is a two or more amino, hydroxyl , Compound containing carboxyl or mercapto groups or an alkali metal salt of an aromatic polyhydroxy compound is used. 5. The method according to at least one of claims 1 to 4, characterized in that the first, second and third, one. Capsule wall-forming substances different compounds can be used. 6. The method according to at least one of claims l to 5, characterized in that the first, second and third substances forming a capsule wall are those from the combination system I to 3 specified below is selected will: 309834/0910 Combination system first, a capsule wall-forming substance, second, a capsule wall
forming substance third substance forming a capsule wall O
CO
OO a polyisocyanate, a polyisocyanate addition product with remainder Isocyanate groups, a polyisothiocyanate or a polyisothiocyanate addition product with remaining isothiocyanate groups and epichlorohydrin an epoxy compound} a polybasic acid chloride and a polyvalent chloroformate; a polyhydroxy compound, a polyamine or an oxide, an epoxy compound, fied product thereof, a polycarboxylic acid, a a polyhydroxy compound, Polythiol (a mercapto-polycarboxylic acid and compound) and a phenol / polythiol; Formaldehyde resin; a polyamine or a modified product thereof j
a phenol / formaldehyde resin, a polyhydroxy compound, a polythiol and
a polycarboxylic acid a polyamine ^ or a modified product thereof a polyamine or a modified product thereof, an alkali metal salt of a phenol / formaldehyde condensate and an alkali metal salt of a polyhydroxy aromatic compound. ^ 7. Ancestors according to at least one of claims 1 to 6 * . characterized in that the Reäktiohssystem a effective amount of a catalyst is added. Bi method according to at least one of claims 1 Bio Ί, characterized in that the reaction at a temperature within the range room temperature to VOH au a dürehgeführt fempörätmr below the boiling point of the polar liquid of the oil barren wircL 9. The method haeh at least one of claims i to 8 ^ - thereby gekenn2eitähnet _r that the Erttiiigieren is completed before egg tim ^ setting, 10. The method has at least one dör claims i to 9 ». characterized * that the product of the reaction of the first substance M forming a capsule wall of the second * substance forming a capsule wall with the
third * a substance forming a capsule wall reacts on the surface of the polar Plüssigkeits / öi-Sräpföheh.