DE2625392A1 - METHOD FOR PRODUCING ORGANIC COMPOUNDS WITH BLOCKED HYDROXYL GROUPS - Google Patents

Description

Bayer Aktiengesellschaft 4 2 625 392

Central area of patents, trademarks and licenses

509 Leverkusen. Bayerwerk

Wr-by

Jun / fir *

Process for the production of organic compounds with blocked hydroxyl groups

The present invention relates to a method for Production of new organic compounds with blocked hydroxyl groups, from which by action Compounds containing hydroxyl groups which are free from moisture are formed, the preferred compounds being formed by this process available compounds, as well as a process for the production of polyurethanes, in which polyisocyanates and mixtures containing compounds which can be hydrolytically converted into polyols to react with water will.

It is well known that polyurethanes, which are made from polyols and Polyisocyanates can be produced, numerous areas of application. In general, the implementation of the starting components takes place but so quickly at room temperature that the reaction mixtures (two-component systems) show no noteworthy storage stability even at room temperature. For the production of storage-stable One-component systems must therefore ensure that the isocyanate groups and / or the hydroxyl groups are ready to react can be canceled by reversible blocking.

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Such one-component systems are, for example, the known mixtures of polyhydroxy compounds and polyisocyanates with blocked isocyanate groups (see e.g. POLYURETHANES, Chemistry and Technology, Part-1, Interscience Publishers, 1962, p. 8}. Connections with blocked, Groups which are reactive toward isocyanate groups are described, for example, in German Offenlegungsschrift 2,446,438 Oxazolidine mixtures of polyisocyanates and such oxazolidines represent systems that can be stored at room temperature which only after the admission of water (humidity) with the release of hydroxyl and amino groups to form polyurethane urea Reacting systems result. The production of these urethane oxazolidines takes place in one multi-stage reaction via the intermediate stage of the corresponding N-Hydroxyalky! -oxazolidine, which with polyisocyanates to be converted to the urethane oxazolidines. The prepolymers containing free isocyanate groups, which are known per se, can also be used as polyisocyanates on the basis of the usual polyhydroxy compounds which can be used in polyurethane chemistry.

The present invention is based on the object of providing a simple method which the reversible blocking of the usual polyhydroxy compounds which can be used in polyurethane chemistry is permitted. This object could be achieved by the invention described below.

The present invention is a process for the preparation of organic compounds with blocked Hydroxyl groups, which under the influence of moisture

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Form polyhydroxy compounds with free hydroxyl groups, characterized in that one mole of a polyhydroxyl compound the formula

P (OH)

with 0.5 η - 1 η mol of an orthocarboxylic acid ester for Reaction brings, whereby

η is an integer from 2 to 8 and

P stands for a residue as it is obtained by removing the hydroxyl groups from an n-valent organic Polyhydroxyl compound of molecular weight range 9O-1O,000 is obtained.

and- wherein the hydroxyl groups of the polyhydroxyl compound P (0H} _n are separated from one another by mine members.

bond P (0H} _n by at least 3 chain

The present invention also relates to preferred compounds of the formula obtainable by this process

-0-C-O- R,

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in which

P and η have the meaning given above and

R ₁ and R "stand for identical or different radicals and mean aliphatic hydrocarbon radicals with 1 to 6 carbon atoms and

R., represents hydrogen or a radical whose meaning _{corresponds to the definition for R 1} or R ".

In the above-mentioned method according to the invention arise organic compounds with terminal groups of the formula

₁
-OCOR,

where R, R and R preferably have the meaning already mentioned. From these terminally blocked hydroxyl-containing compounds, compounds with terminal hydroxyl groups are formed under the action of water (atmospheric humidity) with elimination of low molecular weight R ₁ -OH and carboxylic acid ester R ₃ -COOR _2. This means that mixtures which, in addition to polyisocyanates, contain compounds with the end groups mentioned, are storage-stable in the absence of moisture, and react to the corresponding polyurethanes with the ingress of moisture with intermediate formation of hydroxyl groups.

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ORIGINAL INSPECTED

262: 392

The present invention therefore also provides a process for the production of polyurethanes by reaction of polyisocyanates and polyhydroxy compounds containing free hydroxyl groups under the influence of moisture Mixtures containing forming organic compounds with water, characterized in that under the Influence of moisture, compounds which form polyhydroxy compounds and which have free hydroxyl groups uses the at least 2 radicals of the formula

-0-COR ₀
^R 3

have, where R, R ₀ and R_ have the meaning given above.

The polyols of the formula P (OH) _{n to be blocked according to the invention}

have a molecular weight of 90-10,000, preferably 150-5,000. According to the invention, any polyhydroxy Compounds are used whose hydroxyl groups are replaced by at least 3, preferably at least 4 Chain links are separated from each other. "Chain links" are primarily between the to understand carbon and oxygen atoms arranged in individual hydroxyl groups.

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Examples of suitable polyhydroxy compounds P (° ^H ) are neopentyl glycol, tetramethylene glycol, hexamethylene glycol, octamethylene glycol, 1,5-dihydroxyhexane, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, tripropylene glycol, in particular 2 to the known polyurethane glycol, dibutylene glycol, in particular dibutylene glycol 8 polyesters, polyethers, polythioethers, polyacetates, polycarbonates or polyester amides preferably containing 2 to 4 hydroxyl groups. The first-mentioned low molecular weight polyols and the last-mentioned polyester polyols and polyether polyols are preferred.

The possible polyesters containing hydroxyl groups are, for example, reaction products of polyvalent, preferably dihydric and optionally additionally trihydric alcohols with polyhydric, preferably dihydric, Carboxylic acids. Instead of the free polycarboxylic acids, the corresponding polycarboxylic acid anhydrides or corresponding Polycarboxylic acid esters of lower alcohols or mixtures thereof are used to produce the polyester will. The polycarboxylic acids can be aliphatic, cycloaliphatic, be aromatic and / or heterocyclic in nature and, if necessary, e.g. by halogen atoms, substituted and / or be unsaturated. Examples include: succinic acid, adipic acid, suberic acid. Azelaic acid, sebacic acid, Phthalic acid, isophthalic acid, trimellitic acid, phthalic anhydride, Tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, Glutaric anhydride, maleic acid, maleic anhydride. Fumaric acid, dimers and trimers

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ORIGINAL

262,392

Fatty acids, such as oleic acid, optionally mixed with monomeric fatty acids, dimethyl terephthalate, bisglycol terephthalate. Polyhydric alcohols for the production of polyesters include, for example, ethylene glycol, propylene glycol (1,2) and - (1,3, butylene glycol (1,4) and - (2,3), hexanediol (1,6), octanediol- (1,8), neopentyl glycol, cyclohexanedimethanol (1,4-bis-hydroxymethylcyclohexane), 2-methyl-1,3-propanediol, glycerine, trimethylolpropane, hexanetriol- (1,2,6), butanetriol- (1,2, 4), trimethylolethane, pentaerythritol, quinitol, mannitol and sorbitol, methyl glycoside, also diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycols, dibutylene glycol and polyesters, for example, lactyl glycols, e.g. Hydroxycaproic acid can be used.

Also those that come into question according to the invention, at least two, usually two to eight, preferably two to three, hydroxyl-containing polyethers are such of the type known per se and are e.g. by polymerizing epoxides, such as ethylene oxide, propylene oxide, butylene oxide, Tetrahydrofuran, styrene oxide or epichlorohydrin with itself, e.g. in the presence of BF ^ or by attachment these epoxides, possibly in a mixture or one after the other, on starting components with reactive hydrogen atoms, such as alcohols, phenols or amines, e.g. water, ethylene glycol, propylene glycol- (1,3) or - (1,2), trimethylolpropane, 1,4-dihydroxybenzene, 4,4'-dihydroxydiphenylpropane, aniline, Ammonia, ethanolamine, ethylenediamine produced. Also sucrose polyethers, such as those in the German interpretative publications 1 176 358 and

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■ TED

2B2D392

1,064,938 are suitable according to the invention. Often those polyethers are preferred which predominantly (up to 90% by weight, based on all OH groups present in polyether) have primary OH groups. Polyethers modified by vinyl polymers, such as those used e.g. by polymerization of styrene, acrylonitrile in the presence of polyethers (American patents 3 383 351, 3 304 273, 3 523 093, 3 110 695, German Patent specification 1,152,536) are also suitable, as are polybutadienes containing OH groups.

As polyacetals come e.g. those from glycols, such as diethylene glycol, Triethylene glycol, 4,4'-dioxethoxy-diphenyldimethylmethane, Hexanediol and formaldehyde preparable compounds in question. Also let through the polymerization of cyclic acetals According to the invention, suitable polyacetals can be prepared.

Polycarbonates containing hydroxyl groups are those of the type known per se, which can be obtained, for example, by reaction of diols, such as propanediol (1,3), butanediol (1,4) and / or Hexanediol (1.6), diethylene glycol, triethylene glycol, tetraachylene glycol with diaryl carbonates, e.g. diphenyl carbonate or phosgene.

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ORIGINAL INSPECTED

The polyester amides include, for example, those made from polyvalent saturated and unsaturated carboxylic acids or their anhydrides and polyhydric saturated and unsaturated amino alcohols obtained, predominantly linear Condensates.

The inventive blocking of the polyhydroxyl compounds mentioned is very easy. For this purpose, the polyhydroxyl compound with an orthocarboxylic acid ester is sufficient Approx. 80-2OO ° C, preferably 100-150 ° C.

Suitable orthocarboxylic acid esters are, for example, those of the formula

which ^R 3 - C O
<—O - R ¹ - ^R 4 in

R ₁ , R ₂ and R- have the meaning already mentioned and in which

R- corresponds to the meaning of R ₁ or R _2.

Examples of suitable orthocarboxylic acid esters are trimethyl orthoformate, Triethyl orthoformate, tributyl orthoformate, trihexyl orthoformate, Trimethyl orthoacetate, triethyl orthoacetate, tributyl orthoacetate or Trimethyl orthohexanecarboxylate. Triethyl orthoformate is preferred used.

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In general, the proportions of the reactants are chosen so that per hydroxyl group in the reaction mixture the polyhydroxyl compound to be blocked is 0.5-1 molecule of the orthocarboxylic acid ester. Of course However, it is also possible to use an excess of orthocarboxylic acid esters, which follows the Reaction according to the invention can be removed by distillation.

In the blocking reaction according to the invention, with elimination of alcohol R ₄ -OH, compounds are always formed which have the group at the end

0 - R ₁
-0-COR ₂

^R 3

exhibit. However, this occurs at the same time, especially when using less than the amount of orthocarboxylic acid ester a chain extension or crosslinking reaction with the formation of linkage points of the formulas

0 - R ₁
-POCOP-

0 - P --P-O-C-O-P-

^R 3

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with elimination of R “-OH and optionally R ₁ -OH.

Accordingly, especially when using polyols of higher functionality, P (OH) becomes extensive Avoidance of the formation of excessively highly crosslinked process products in equivalent proportions the reactant preferred. With this preferred use, equivalent amounts of the reactants are formed preferably compounds of the formula

0 - R ₁
-0-COR

R ₃ .

In these formulas, P, R-, ι- R ₂ , ^R 3 ^{and n have the} meaning already mentioned.

The blocking reaction according to the invention can be carried out in the presence of suitable, inert solvents. However, it is preferred to work without solvents. The split off in the blocking reaction according to the invention By-products (low molecular weight alcohols) are removed from the reaction mixture by distillation. The history the blocking reaction can be followed quantitatively by determining the amount of by-products distilled off will.

Both the terminal groups of the formula that are always present in the blocked polyols

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O - R ₁
-0-COR

^R 3

as well as the linking and networking points of the formulas

O - R ₁
-POCOP

^R 3

O - P -P-O-C-O-P-

^R 3

are very likely to have the corresponding free hydroxyl groups under the influence of moisture Connections split. In any case, it was found that mixtures of the last-named 3 groupings on pointing compounds blocked according to the invention with polyisocyanates are storage-stable in the absence of moisture are, however, under formation in the presence of moisture of polyurethanes react.

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ORIGINAL INSPECTED

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In the process according to the invention for producing polyurethanes, the processes according to the invention are accordingly blocked compounds mixed with polyisocyanates, in addition to the hydrolytic cleavage of the orthoester groups accelerating catalysts, the auxiliaries and additives customary in polyurethane chemistry are used can be.

In the production of the polyurethanes according to the invention, the type and amount of the reactants are chosen so that that the molar ratio between isocyanate groups and the total amount of alcoholic hydroxyl groups present after hydrolysis of the blocked compounds between 0.8: 1-2: 1, preferably 1: 1-1.6: 1. In addition, the circumstance must be taken into account That in this hydrolysis monohydric alcohols, i.e. alcohols acting as chain terminators, are split off. This means that in the process according to the invention for the production of polyurethanes preferably tri- and Higher-functional polyisocyanates are used to reduce the chain-breaking effect of the hydrolytically split off to compensate for monohydric alcohols. This is particularly important when using an NCO excess Complete compensation is not required, since when using an excess of isocyanate in addition to the NCO / OH reaction further crosslinking reactions via allophanate groups are possible. A complete compensation for the chain breaking Effect of the split off monohydric alcohols exclusively via NCO / OH reactions would be how easy can only be seen if at least tetrafunctional polyisocyanates are used.

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In fact, however, it turned out that triisocyanates when using a suitable excess isocyanate (NCO / OH ratio about = 1.5) is sufficient. From the The reason given above, the use of diisocyanates is less preferred, although also when using diisocyanates the chain-breaking effect due to the split off monohydric alcohols when using a corresponding one Excess diisocyanate compensated for by secondary crosslinking reactions via aliophanate groups could be.

Suitable polyisocyanates for the process according to the invention are aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates, as described, for example, by Siefgen in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136, for example ethylene diisocyanate, 1,4 -Tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3 and 1,4-diisocyanate and any mixtures of these isomers. 1-isocyanato-3,3, S-trimethyl-S-isocyanatomethyl-cyclohexane (DAS 1 202 785), 2,4- and 2,6-hexahydrotolylene diisocyanate and any mixtures of these isomers, hexahydro-1,3- and / or - 1,4-phenylene diisocyanate, perhydro-2,4- and / or -4,4'-diphenylmethane diisocyanate, 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2,6-tolylene diisocyanate and any mixtures of these isomers , Diphenylmethane-2,4 ¹ - and / or -4,4'-diisocyanate, napthylene-1,5-diisocyanate, triphenylmethane-4,4 ', 4 "-triisocyanate, polyphenyl-polymethylene-polyisocyanates, as they are by aniline Obtain formaldehyde condensation and subsequent phosgenation and, for example, in the

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Iq

British patents 874 430 and 848 671 are described, perchlorinated ary! polyisocyanates, as for example in the German Auslegeschrift 1 157 601 are described, carbodiimide-containing polyisocyanates, as described in German patent specification 1 092 007 can be described. Diisocyanates as described in the American patent 3,492,330, polyisocyanates containing allophanate groups, such as those described in British Patent 994 890, Belgian patent specification 761 626 and published Dutch patent application 7 102 are described, polyisocyanates containing isocyanurate groups, As for example in the German patents 1 022 789, 1 222 067 and 1 027 394 as well as in the German Disclosure documents 1 929 034 and 2 004 048 described are, urethane group-containing polyisocyanates, such as those in Belgian patent 752 261 or in US Pat. No. 3,394,164, polyisocyanates containing acylated urea groups according to German Patent 1,230,778, polyisocyanates containing biuret groups, such as those used, for example, in German Patent specification 889 050 and in French patent specification 7 017 514 are described by telomerization reactions manufactured polyisocyanates, such as those described in Belgian patent specification 723 640, Polyisocyanates containing ester groups, such as those described, for example, in British Patents 956,474 and 1,072,956, in in the American patent 3,567,763 and in the German patent 1,231,688, translation products are mentioned of the above-mentioned isocyanates with acetals according to German Patent 1,072,385.

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It is also possible to have the isocyanate groups obtained in the technical production of isocyanates Use distillation residues, optionally dissolved in one or more of the aforementioned polyisocyanates'. It is also possible to use any desired mixtures of the aforementioned polyisocyanates.

In addition to the trifunctional and higher-functional representatives of the polyisocyanates mentioned, in particular those in the Prepolymers containing free isocyanate groups known from polyurethane chemistry are preferred, as they are obtained by reaction of preferably at least trifunctional polyhydroxyI compounds are accessible with excess amounts of diisocyanates of the type mentioned. With these NCO prepolymers underlying polyhydroxy compounds can be both low molecular weight polyols such as e.g. Trimethylolpropane or even higher molecular weight polyester or polyether polyols of the type already mentioned Act.

The implementation between the blocked according to the invention Polyols and the isocyanate component take place after exposure of water, e.g. atmospheric moisture, on the mixtures containing both components. Here It is surprising that the hydrolysis of the blocked polyols and their subsequent implementation are evident with the isocyanate groups of the polyisocyanate component proceeds faster than the direct reaction between isocyanate groups and water.

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Air

This is due to the small amount of the fractions that can be extracted from the polyurethanes, which implies allows the polyols to be incorporated into the polyurethanes ultimately obtained, while in a direct one A chemical fixation of the polyols would not have taken place between isocyanate groups and water and these should therefore be extractable.

The hydrolytic cleavage of the polyols blocked according to the invention can be accelerated by using acidic catalysts such as, for example, p-toluenesulfonic acid or phosphoric acid. In addition to these catalysts, the auxiliaries and additives customary in polyurethane chemistry can be used in the mixtures for the production of the polyurethanes according to the invention. These include catalysts that accelerate the NCO / OH reaction, such as tertiary amines, such as triethylamine, tributylamine, N-methyl-morpholine, N-ethyl-morpholine, N-cocomorpholine, Ν, Ν, Ν ¹ , N'-tetramethyl-ethylenediamine, 1,4-diazabicyclo- (2,2,2) -octane, N-methyl-N-dimethylaminoethyl-piperazine, N, N-dimethylbenzylamine, bis- (N, N-diethylaminoethyl) -adipate, Ν, Ν-diethylbenzylamine , Pentamethyl diethylenetriamine, N, N-dimethylcyclohexylamine, Ν, Ν, Ν ¹ , N ¹ -tetramethyl-1,3-butanediamine, N, N-dimethyl-ß-phenylethylamine, 1,2-dimethylimidazole, 2-methylimidazole.

Silaamines with carbon-silicon bonds are also used as catalysts, as described, for example, in German patent specification 1 229 290, in question, e.g. 2,2,4-trimethyl-2-silamorpholine, 1,3-diethylaminomethyl-tetramethyl-disiloxane.

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Nitrogen-containing bases, such as Tetraalkylammonium hydroxides, also alkali hydroxides such as sodium hydroxide, alkali phenolates such as sodium phenolates or Alkali alcoholates, such as sodium methylate, are suitable. Hexahydrotriazines can also be used as catalysts will.

According to the invention, organic metal compounds, in particular organic tin, zinc and lead compounds can be used as catalysts.

Tin (II) salts are preferably used as organic tin compounds of carboxylic acids, such as tin (II) acetate, tin (II) octoate, Tin (II) ethyl hexoate and tin (II) laurate and the dialkyl tin salts of carboxylic acids such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate or dioctyltin diacetate into consideration.

Preferably combinations of acidic, the catalytic cleavage of the blocked; Polyols accelerating catalysts used with the exemplified organometallic catalysts for the NCO / OH reaction. The catalysts are generally used in amounts totaling from 0.001 to 10% by weight.

Surface-active additives can also be used according to the invention can also be used. The sodium salts of castor oil sulfonates or of fatty acids, for example, are used as emulsifiers or salts of fatty acids with amines, such as oleic acid diethylamine or stearic acid diethanolamine in question. Even Alkali or ammonium salts of sulfonic acids such as of

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Dodecylbenzenesulfonic acids or dinaphthylmethanedisulfonic acid or of fatty acids such as ricinoleic acid or of polymers Fatty acids can also be used as surface-active additives.

According to the invention, reaction retarders, e.g. acidic substances such as hydrochloric acid or organic acid halides as well as pigments or dyes and flame retardants of the type known per se, e.g. tris-chloroethyl phosphate or ammonium phosphate and polyphosphate, furthermore Stabilizers against aging and weathering influences / plasticizers and fungistatic and bacteriostatic Substances, fillers such as barium sulfate, kieselguhr, soot or whiting chalk can also be used.

Further examples of possibly also to be used according to the invention surface-active additives, reaction retarders, stabilizers, flame-retardant substances, plasticizers, Dyes and fillers as well as fungistatic and bacteriostatic substances and details About the use and mode of action of these additives are in the Kunststoff-Handbuch, Volume VI, published by Vieweg and Höchtlen, Carl-Hanser-Verlag, Munich 1966, e.g. on pages 103 to 113.

The process according to the invention for the preparation of polyurethanes can be carried out in the presence of solvents will. Suitable solvents are, for example, the usual paint solvents such as ethyl acetate, butyl acetate, methyl ethyl ketone, Methyl isobutyl ketone, toluene or xylenes or from mixtures of such solvents.

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The low molecular weight formed in the hydrolytic cleavage according to the invention of the polyols blocked according to the invention Ester also has the effect of a solvent that during and / or after the chemical The curing of the mixtures used in the process according to the invention for producing the polyurethanes evaporates.

The process according to the invention for producing the polyurethanes Can be used in particular for the production of films, lacquers, coatings, sealants, impregnating agents or adhesives can be used for natural or synthetic substrates. Coatings or films can be from the compositions with or without solvents permanently or removable on a suitable substrate, such as metal, glass, wood, plastic, paper or leather, possibly with the use of adhesion promoters, such as Silanes.

According to the invention, the blocked polyols are used in the following exemplary embodiments Production and combinations of the blocked polyols with polyisocyanates explained in more detail.

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example 1

Implementation of triethylene glycol and triethyl orthoformate. Molar ratio: 1: 2

100 g of triethylene glycol and 200 g of triethyl orthoformate are placed in a flask equipped with devices for stirring, adding, heating and a distillation apparatus. After heating, a distillate with a boiling range of 80-82 ° C passes over at approx. 110 ° C. Towards the end of the reaction, the reaction ^{temperature is briefly increased to approx. 150 °} C., a total of approx. 60 g of distillate being obtained. The reaction has ended after a total of 1 hour. The blocked diol is obtained as a liquid, light-colored distillation residue.

Viscosity of the diol at 20 ° C: approx. 50 mPa.s viscosity of the reaction product

at 20 ° C: approx. 10 mPa.s

Distillate composition

Ethanol approx. 90%

Triethyl orthoformate approx. 6.5%

Ethyl formate approx. 3%

unknown substances approx. 0.5%

Example 2

Implementation of triethylene glycol and triethyl orthoformate. Molar ratio: 1: 1.8

Production method as in example 1.

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Approach: 100 g of triethylene glycol and 180 g of triethyl orthoformate

Amount of distillate: approx. 60 g

Example 3

Implementation of triethylene glycol and triethyl orthoformate. Molar ratio: 1: 1

Production method as in example 1.

Approach: 150 g of triethylene glycol and 150 g of triethyl orthoformate

Amount of distillate: approx. 85 g

Viscosity of the product at 20 ° C: approx. 845 mPa.s.

Example 4

Implementation of a linear polyether polyol based on propylene oxide, molecular weight approx. 2000 g. mol ~ and 1.7% hydroxyl content, and triethyl orthoformate. Molar ratio: 1: 2

Production method as in example 1.

Approach: 1000 g of polyol and 150 g of triethyl orthoformate .

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Amount of distillation: approx. 30 g

Viscosity of the starting polyol at 20 ° C: 340 mPa.s.

Viscosity of the product at 20 ⁰ C: 310 mPa.s

Example 5

Implementation of a linear polyester polyol based on adipic acid and diethylene glycol, hydroxyl content approx. 1.7%, with triethyl orthoformate.
Molar ratio: 1: 2

Production method as in example 1.

Approach: 300 g of polyol and 45 g of orthoformic acid

triethyl ester

Amount of distillate: approx. 10 g

Viscosity of the starting polyol at 20 C: approx. 12,000 mPa.s. Viscosity of the reaction product

at 20 ° C: approx. 19000 mPa.s

Example 6

Implementation of a tetrafunctional polyether polyol (propoxylated pentaerythritol), hydroxyl content 11.2%, with triethyl orthoformate.
Molar ratio: 1: 4

Approach: approx. 150 g of polyol and 150 g of triethyl orthoformate

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Production method analogous to example 1. Amount of distillate: approx. 41 g

The mixture is heated to 123 ° C. over the course of 20 minutes, ethanol passes over at 80 ° C., and finally the temperature increases in the reaction mixture to approx. 145 ° C. Duration of the experiment approx. 1 hour.

Viscosity of Ausgangspolyols at 20 ⁰ C: 1100 mPa.s viscosity of the reaction product

at 20 ° C: approx. 120 mPa.s.

Example 7

Implementation of 1,4-Ris- (2-hydroxyethoxy) -benzene and Triethyl orthoformate.

Molar ratio: 1: 2

Approach: approx. 100 g of 1,4-bis (2-hydroxyethoxy) benzene

and 150 g of triethyl orthoformate.

Production method analogous to Example 1
Amount of distillate: approx. 47 g

The suspension is heated slowly, at approx. 83 ° C a homogeneous solution is formed, at approx. 103 ° C ethanol passes over, Finally, the temperature in the reaction mixture increases to approx. 145 ° C. Duration of the experiment approx. 1 hour.

Viscosity of the reaction product at 20 ° C: approx. 70 mPa.s.

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Example 8

Implementation of triethylene glycol and trimethyl orthoformate. Molar ratio: 1: 1.8

Approach: 100 g of triethylene glycol and 127.5 g of ortho-

trimethyl formate

The production method cannot be carried out as in Example 1, since the implementation is only imperfect. The following modification of the manufacturing method, for example, is successful. The mixture is heated over 20 min to about 110 ⁰ C, then held for a further 2 hours at reflux. A distillate with a boiling range of approx. 65 - 70 ° C then passes over.

Amount of distillate: approx. 40 g

Viscosity of the reaction product at 20 ° C: approx. 10 mPa.s.

Example 9

100 g of the blocked polyol according to Example 2, 0.6 g of dibutyltin dilaurate
0.12 g p-toluenesulfonic acid

47Og of a solution of an isocyanurate group Polyisocyanate made by catalytic trimerization a mixture of 3 moles of 2,4-diisocyanatotoluene and 2 moles of hexamethylene diisocyanate; mean NCO functionality = 4; 60% solution in butyl acetate; NCO content of the solution = 10.5%.

The mixture is stored for 5 days, then glass plates and steel sheets are coated with a wet film thickness of 150 μm. Thieves-

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Layers are dust-dry after 15 minutes at room temperature and a relative humidity of 50% cure clear and bubble-free.

Pendulum hardness according to DIN 53 157 156 s after 1 day Erichsen depression according to DIN 53 156 0.5 mm after 1 day

Fractions of the films obtained which can be extracted with ether: approx. 0.3%.

Example 10

100 g of the blocked polyol according to Example 5, 0.2 g of dibutyltin dilaurate

0.04 g p-toluenesulfonic acid
100 g of the polyisocyanate solution from Example 9

The mixture is stored for 5 days, then glass plates and steel sheets are coated to a wet film thickness of 150 μm. the Coatings are dust-dry after 3 1/2 hours at room temperature and a relative humidity of 50% and cure clear and bubble-free.

Film properties after: 1 day 12 days

Pendulum hardness according to DIN 53 157: 35 s 55

Erichsen depression according to DIN 53 156: 9.6 mm (sheet metal crack) 8.0

Fractions of the films obtained that can be extracted with ether: approx. 6%

Example 11

100.0 g of the blocked polyol according to Example 2, 5.0 g of dibutyltin dilaurate
1.0 g of phosphoric acid

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262O92

1700.0 g of a branched, higher molecular weight polyisocyanate, made from polypropylene oxide polyether polyol and 2,4-diisocyanatotoluene; NCO content = 3.5% Viscosity at 20 ° C = approx. 8000 nPa.s.

Thick films cure within 4 days at room temperature and a relative humidity of 50% bubble-free through. The above-mentioned mixture can be stored for more than 1 month at 50 ° C.

Example 12

100 g of the blocked polyol according to Example 7, 470 g of the polyisocyanate solution according to Example 9.

Films produced from the storable mixture are at room temperature and a relative humidity of 50% dust dry after 10 minutes and harder clear and free of bubbles.

Example 13

100.00 g of the blocked polyol according to Example 6 190.00 g of a 75% solution in ethyl acetate

Reaction product of 3 moles of 2,4-diisocyanatotoluene and 1 mole of trimethylolpropane 0.20 g of d-butyltin dilaurate
0.04 g p-toluenesulfonic acid

Films produced from the storable mixture cure at room temperature and a relative humidity of 50% clear and bubble-free.

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Example 14

100.0 g of the blocked polyol according to Example 7, 0.5 g of dibutyltin dilaurate 0/1 9 p-toluenesulfonic acid

190.0 g of the polyisocyanate containing biuret groups from 3 moles of hexamethylene diisocyanate and 1 mole of water; NCO content = 22%, average NCO functionality = 3.

Coatings produced from the storable mixture are after about 5 hours at room temperature and one relative humidity of 50% dust-dry.

Example 15
(Making a sealant)

10.0 g of blocked polyol according to Example 6

95.0 g of the polyisocyanate from Example 11

105.0 g alkyl sulfonic acid ester _{(C 1} JH _{31 -SO 3} -CgH _1. )

1.0g lead octoate (24% Pb)

0.2 g of p-toluenesulfonic acid

12.0 g of highly disperse silica

40.0 g of polyvinyl chloride powder

5.0 g titanium dioxide

0.2 g of carbon black

5.0 g zeolite powder (molecular sieve)

The specified storable sealant compound hardens at room temperature and a relative humidity of 50% for approx. 1 mm per day. Shore A hardness of the material =

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ORIGINAL INSPECTED

Claims (4)

262S392 claims 1. Process for the production of organic compounds with blocked hydroxyl groups which, under the influence of moisture, form polyhydroxyl compounds with free hydroxyl groups, characterized by that one T moles of a polyhydroxyl compound of the formula P (OH) _n with 0.5 η - 1 η mol of an orthocarboxylic acid ester to react, wherein η is an integer from 2 to 8 and P stands for a residue as it is obtained by removing the hydroxyl groups from an n-valent organic Polyhydroxyl compound of molecular weight range 90-10,000 is obtained, and wherein the hydroxyl groups of the polyhydroxyl compound P (OH) each by at least members are separated from each other. bond P (OH) through at least 3 chain 2. The method according to claim 1, characterized in that the orthocarboxylic acid ester is triethyl orthoformate used. 709850/0416 Le A 17 231 - 29 - ORIGINAL INSPECTED 262S332 a * 3./Compounds of the formula P- f O - C - O - R ,,, η
in which P and η have the meaning given in claim 1, R, and R2 stand for identical or different radicals and aliphatic ^ mean hydrocarbon radicals with 1 to 6 carbon atoms and R- represents hydrogen or a radical whose meaning corresponds to _{the definition for R 1} or R _2. 4. Process for the production of polyurethanes by reacting polyisocyanates and under the influence of Polyhydroxy compounds containing moisture-free hydroxyl groups Mixtures containing forming organic compounds with water, characterized in that that as polyhydroxyl compounds having free hydroxyl groups under the influence of moisture Forming compounds are those which have at least 2 radicals of the formula -0-COR ₂
* 3 709850/0416 Le A 17 23T - 30 - wherein R., R "and R, those mentioned in claim 3 Have meaning. * l Le A 17 231 - 31 -