DD132018B1 - METHOD FOR PRODUCING HYDROXYL GROUP-CONTAINING ESTERS OF FATS - Google Patents

Description

Field of application of the invention

The process serves to obtain products which are suitable for the production of polyurethane, preferably casting resins, baking and foaming.

Charakterist ik the known t echnical Lös Ungen

Hydroxyl-containing fatty acid esters can be obtained according to the known prior art by the following processes:

A) Esterification of fatty acids with alcohol components to fatty acid ester alcohols

B) Transesterification of fats with alcohol excess

In the oxidation (C) of peracid derivatives, mixtures of substances with different functionality are obtained. The products produced by this process lead to structural inhomogeneities in the production of polyurethanes.

Method D leads to well-defined products. However, if products with OH functionality = 2 are obtained, a relatively high effort is required. Epoxies which already have OH functionality (eg glycidyl compounds) and / or higher functionality fatty acids (eg, dimerized fatty acids) must be used.

Method E also allows the production of well-defined compounds. However, according to this method, products are often obtained which are in the range of higher OH numbers and thus can not be used for some PU application areas. In addition, the hydrogenation is associated with very high economic outlay.

The method E has the further disadvantage that essentially only the expensive product - epoxidized fatty acid derivative - serves as a starting material.

Process F combines the economically favorable aspects of processes A, B and C (using cheaper reaction components) and the reaction-technically advantageous processes D and E (obtaining products with a well-defined structure). The disadvantage of the method F according to the prior art is that for the production of products with low viscosity and high hydrophobicity, the use of epoxidized natural fats or oils (ie of glycerides) is not possible. The reason for this is the high branching occurring in the splitting of the epoxide groups, which causes an increase in viscosity in the known processes. Therefore, it has already been proposed to use epoxidized monoalkyl esters. However, this use requires complex processing steps for the preparation of these products by transesterification of the glycerides with monools or cleavage of the fats or oils and subsequent reaction of the liberated carboxylic acids with monofunctional reactants.

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Another disadvantage of this known method is the limitation of the alcohol components which are suitable for the reaction with the epoxide. If products with an OH functionality greater than 1 are to be obtained, then the use of monools is prohibited since a large part of the technically epoxidized fatty acid monoalkyl esters has only one epoxide group. The use of higher-functionality alcohols which is necessary here in turn leads to an increase in the hydrophilicity of the reaction product that is detrimental for many applications.

d) Object of the invention

The aim of the invention is the development of a process for the preparation of OH-functional fatty acid derivatives with low viscosity, high functionality, low reactivity, good isocyanate compatibility and max. Hydrophobicity based on epoxidized fats and oils.

e ) Presentation of the invention of the invention

The object of the invention is to develop a process for the preparation of hydroxy-containing esters of fatty acids, which at low cost allows the production of higher-functional products with low viscosity and good hydrophobicity.

Features of the invention

The process for the preparation of low-viscosity, hydrophobic, hydroxyIgruppenhaltiger esters of fatty acids with high OH functionality is characterized in that epoxidized natural fats and oils with polyether alcohols of the general formula

with R _{1 B} H, OH

R ₂ , R ^ = H, OH or Alky! Group

m & 1 to be implemented.

e) presentation; the essence of the invention

- Technical problem, which duro'h the invention is achieved

The object of the invention is to develop a process for the preparation of hydroxyl-containing esters of fatty acids, which at low cost allows the production of higher-functional products with low viscosity and good hydrophobicity,

Features of the invention

The process for preparing low-viscosity, hydrophobic, hydroxylgr ⁿ ppenhaltiger esters of fatty acids with a high OH functionality is characterized in that epoxidized natural fats and oils with Polyätheralkoholen of the general formula

with E ₁ = H, OH

E ₂ , E ss H, OH or alkyl group

m => 1

η = 3 and / or> 5

be implemented.

As the polyether alcohol is a condensate of butanediol-O »3)» optionally used in combination with monools long carbon chain,

Polyether alcohols of this type are distinguished by their special structure, by significantly greater hydrophobicity and by low viscosity compared to polyether alcohols which have been obtained by alkylene oxide addition. In addition, these products contain a high proportion of secondary OH groups, which causes low reactivity.

The reaction can be carried out in a conventional manner by addition of the neutral alcohol component to the epoxide in the presence of catalysts, e.g. 3. boron trifluoride ethyl etherate

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be carried out at normal temperature, followed by reaction at 160 ⁰ O.

A better space-time enhancement is achieved when both reactions, etherification and reaction are coupled with the epoxide. The reaction of the epoxide can be carried out at temperatures between 100 ⁰ C and 200 ⁰ C. At high temperatures, a steady tracking of the epoxide content during the reaction is required to complete the reaction in a timely manner, as side reactions take place after the epoxide has reacted.

In the course of further reaction, the remaining acid and / or a Lewis acid, for. B. Bortrifluoräthylätherat be used as a catalyst. According to the invention, the storage stability of the product can be ensured by maintaining a stabilizing epoxide content, whereby an epoxide content of about 1 % must be maintained. The hydrophobicity of the product can be improved if a part of the polyether alcohol used according to the invention is replaced by long-chain monools. Ss shows that reaction products of epoxidized fats and oils with Llonoolen have a poor compatibility with isocyanates, while the use of Llonoolen in admixture with the polyether alcohols used in the invention, a sufficient compatibility is achieved. Therefore, the hydrophobicity of the product can be improved by partial incorporation of long carbon chain monools. The conversion of epoxidized fatty acid glycerides with polyether diols gives products with very high functionality at low viscosity. This leads to a very good stability during processing in the polyurethane system.

The economic effort to achieve the properties of the product is minimal due to the simple procedure.

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The invention will be explained in more detail below to 6 exemplary embodiments.

Embodiment 1

a) To 3260 g epoxidized. Soybean oil at room temperature and with stirring 3770 of a polypropylene glycol OHZ 355 containing 0.1% Bortrifluoräthylätherat given. After completion of the addition, the temperature is raised to 150 ⁰ C within 3 hours and at this temperature, the reaction is continued for about 2 hours. The polyol thus prepared has the following characteristics:

OHZ / "mg KOR / & J J 220 SZ /" mg K0H / g_7: 1,0 Viscosity at 20 ⁰ CgSJt 3700 Epoxide content C% J ^: ° »°

b) 3260 g of epoxidized soybean oil are reacted according to Example 1 a) with 3770 g of a polyether alcohol produced by acid condensation of 1,3-butanediol OHZ 340, which contains 0.1% Bortrifluoräthylätherat reacted. The product has got the following characteristics:

OH / mg K0H / g_7: 190

SZ / "mg K0H / g_7: 0.4

Viscosity at 20 ⁰ GfQPJi 700

Epoxy content £ "% J г 0.3

The comparison with Example 1 a) shows a strong reduction in the viscosity of the product. This product is stable at 25 ⁰ G for У 2 years, when stored at 80 Ö, it comes very quickly to a sharp increase in the acid number.

Execution Example 2s

a) 1 kg of a product prepared according to Example 1 b) is neutralized with 40% HaOH and then

о _

drained at 20 torr and 100 ⁰ O. The following characteristics were determined before or after б months storage at 80 ⁰ G:

before storage after storage

OH number: 186 187

Acid number: 0.4 0.85

Epoxide content: 0.25% 0.2%

H ₂ O contentj 0.05% 0.11 %

Viscosity b.20 ⁰ O: 720 cP 730 cP

b) To 1 kg of a product prepared according to Example І b) is added so much epoxidized soybean oil that an epoxide content of 1 % is achieved · The following characteristics were determined before or after storage for several months:

before storage after storage

OH number: 184 184- Acid number: 0.65 0.54 Epoxide content: 1 % 0.7 % Viscosity b. 20 ⁰ C: 63o cP 675 cP HpO content: 0.2 % 0.2 % Embodiment 3

To 377 9 g of a polyether alcohol of OHZ 34O, which was obtained by sulfuric acid condensation of butanediol 4i, 3) and still contains 0.1 % HpSO ₂ , 3250 g of epoxidized soybean oil are added.

After two hours of reaction at 160 ⁰ O, the product is neutralized with 40iger sodium hydroxide solution and dehydrated analogously to Example a). The following characteristics were determined before or after 6 months of storage at 80 ^° C.:

before storage after storage

OH number: 190 189 Acid number: 0.1 Q, 15 Epoxide contentj 1.1% 1.0 Viscosity b. 20 ⁰ C: ^ O cP 6.20 cP H ₂ 0 content: 0.04% 0.07 % Execution of game 4:

In a 100 l stirred tank, alcohol of OHZ 34O, prepared by etherification of butanediol- (1.3) with 0.1% ^H p ^S0 4 ^{as Каѣа1} У ^оа ' ^Ьпг , is added to 48 kg of polyethylene

p4

of neutralization, 42 kg of epoxidized soybean oil at 70 ⁰ C. After mixing, a temperature of 130 ⁰ C sets, and there is the addition of 76 g of boron trifluoride ethyl etherate. The temperature is raised to 160 ⁰ C and the reaction continued for 1.5 hours at this temperature and Yakuum. Thereafter, the product is cooled in a stirred tank and filled at 80 ⁰ C. The polyol has the following characteristics:

OH / mg K0H / gJ7: 190

SZ / "mg KOR / gJ: 0.6

Viscosity b. 20 ⁰ C: 550

Epoxide content / ~% _7: 1.05

Ausfüiirungsbeisp iel 5:

370 kg of butanediol (1.3) with 740 g conz. H ₂ SO ^ presented and heated in an enameled Eührreaktor with distillation apparatus to 180 ⁰ C. After 40 kg of condensation water are separated, gradually epoxidized soybean oil is added in order to maintain an epoxide content of the reaction mixture of about 0.8. Once 80 kg of condensate are deposited, the temperature is lowered to 160 ⁰ C and the remaining epoxy (total 173 ^k S are used) zubegeben. Further processing is analogous to example 5,

It becomes a polyol with the characteristics

OHZ / "mg KOH / g J χ 195

SZ / ~ mg KOH / g 7 ί 0.3

Ϊ ² ° ^Ό ro * J "ι ⁵ ^

Epoxide content / ~% _7: 1.08

receive.

Ausführungsbe ispiel 6;

50 parts of a prepared according to Example 5 hydroxy1-containing fatty acid derivative, 35 parts barite, 8 parts of a polyether alcohol based on glycerol propylene oxide with an OHZ ^ 400, 8 parts of a dehydrating paste based on iTatriumaluminiumsi likat zeolite structure are homogenized and after 24 hours with 44 parts of a polymeric crude product of Diphenylmethandiis ^ cyanats (NCO equivalent weight 135) crosslinked. After curing, the mixture gives a tough hard coating compound (Snore D hardness 70). Due to the long service life, the low viscosity and the self-leveling properties, the material is particularly suitable for hand processing. The hydrophobic behavior of the system avoids blistering and good surface quality; reached.

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Claims (1)

invention claims 1. A process for preparing low-viscosity, hydrophobic esters of fatty acids having high OH functionality, characterized in that epoxidized natural fats and oils with polyether alcohols of the general formula R ₁ - (GR ₂ R ₃ ) - 0 T- with R ₁ = H, OH R ₂ , R- = H, OH or alkyl groups m ^ be reacted in known manner or by addition of the epoxide to the alcohol at temperatures of 100 ⁰ C to 200 ⁰ C in the presence of acidic catalysts and in the reaction product, a stabilizing epoxide content of about 1 % is maintained. Process according to item 1, characterized in that a condensate of butanediol- (1,3) "optionally in combination with monools of long carbon chain is used as the polyether alcohol. Process according to items 1 and 2, characterized in that the catalyst of the polyether alcohol synthesis simultaneously serves as a catalyst for the reaction of the epoxide. Process according to items 1 to 3 », characterized in that a variation of the concentration of the catalyst acid takes place by partial addition of the epoxide.