CS250038B1 - Process for producing polyester polyols - Google Patents

Abstract

The production of polyester polyols, mainly suitable for the production of polyurethanes, is carried out by esterification, respectively. transesterification and polyesterification in one or two stages of the secondary oxygenated organic product from the production of cyclohexanone and cyclohexanol by oxidation of cyclohexane, the aqueous portion from washing the reaction mixture with water vapor in an expansion vessel after partial concentration of alcohol and a specific by-product separated as an organic residue from the hydrolysis of the oxidate after separation of low-boiling substances, which has an acid number of 150 to 310 (240 to 290 J mg KOH/g and a saponification number of 250 to 480 (380 to 450 J mg KOH/g. It is esterified, or transesterified and polyesterified with at least one diol to polyol (ethylene glycol, diethylene glycol, propylene glycol, polyglycols, pentaerythritol, dipentaerythritol, polyvinyl alcohol and others, respectively, with their immediate precursor (alkyloxy- ■rainy, epichlorohydrin).

Description

250038

BACKGROUND OF THE INVENTION The present invention relates to a process for the preparation of polyester polyols which is readily available, including the secondary oxygenated petrochemical raw materials.

Polyesterpolyols are mainly based on adipic acid and divalent to polyhydric alcohols (Korsak, GolOgubov: Izv. Akad. Nauk SSSR otd. Chim. 1949, p. 379; U.S. Pat. No. 3,010,943, 2,895,926, 2,916,464 No. 3,823,089 and 797,576, German Patent No. 1,112,285, 1,166,852, and 1,178,528). Nos. 1,112,285, 1,166,855, and 1178,588).

However, in some instances adipic acid substitutes partially or completely violet acid (U.S. Pat. No. 2,892,813 and No. 2,905,652), or other dicariic acids such as succinic, glutaric, pimelic, corkic, sebacic, and the like. azelain (Dobrov EA: Polyurethanes. SNTL Praha 1961; BIOS Philanth Report No 1,498), further) linoleic acid. Of the aromatic acids, polyols are produced for elastomers such as 1,3-propanediol and 1,4-butanediol with isophthalate and terephthalic acid (V. Brit. U.S. Pat. Nos. 1,313,678, 1,323,727 and 1,351,874); mainly from lactone, s-caprolactone (Ind. Eng.Prod. Res. and Develop. 2: 27 (1963)). In general, the amount of individual components is used to produce polyester polyols from dicarboxylic to polycarboxylic acids or their anhydrides and divalent to polyhydric alcohols, depending on the nature of the raw materials used and the desired properties of the final polyester polyol GeeG .: Trans. Cloak. Inst., London 26, 187 (1958); Cloak. 35, 9, 145 (1958)).

Polyesterification is carried out with the abovementioned starting materials, as a rule, in the presence of an esterification or polyesterification catalyst, respectively. mixtures of catalysts, usually at temperatures of 130 to 240 degrees C atmospheric pressure, or slightly elevated, while separating the reaction water with inert gas or azeotropic distillation, most often with xylene or other "blower". However, the development of such products is limited by the inadequate sources of dicarboxylic or polycarboxylic acids.

However, in addition to the preparation of polyester polyols from defined pure dicarboxylic acids or their anhydrides, the processes for the production of polyester polyols from the distillation residue from the production of terephthalic acid or its dimethyl ester (U.S. Pat. No. 218,170) are known.

Despite the many technical advantages, these polyester polyols do not meet all the requirements for some of the applications and, in addition, the raw materials of the polyester polyols are diminished with the ever increasing selectivity of p-xylene oxidation to terephthalic acid and dimethyl terephthalate.

The use of oxygen-side by-products from the production of cyclohexanone and / or cyclohexanol by oxidation of cyclohexane to produce polyester polyols by esterification and / or transesterification and / or polyesterification with diols to tetraols is protected. AO No. 229 429.

The disadvantage of this process is that we use only the distillation residue of the production of cyclohexanone with a high content of dark, bituminous compounds, which in some cases cause technical problems in further processing. Therefore, for multiple applications, it is desirable to start from separate separate organic compound pools from the production of cyclohexanone by oxidation of cyclohexane (e.g., the product of DK-109) or to process products with bituminous compounds under altered reaction conditions.

This problem is solved by a process for the preparation of polyester polyols by esterification and / or pre-esterification and / or polyesterification of organic di- to polyhydroxy compounds with a secondary oxygenated organic product by the formation of cyclohexanone and / or cyclohexanol by oxidation of cyclohexane such that The selenium component uses the by-product separated as an organic residue by washing up the reaction mixture with aqueous steam or from hydrolysis of the oxidate to the separation of unconverted cyclohexane, the main product and a portion of the predominantly organic and water, optionally with the addition of dicarboxylic acids and / or their anhydrides. An advantage of the process according to the invention is the significant technical use of the by-product, in particular from the production of cyclohexanone and cyclohexanol by oxidation of cyclohexane, but also by-products from the production of trimethylolpropane and pentaerythritol for some polyester polyols. Thereafter, flexibility is required by the qualitative requirements of the final polyester polyol as well as the availability of other raw material components.

Esterification, transesterification as well as esterification according to the invention can also be carried out without catalysts, but more preferably catalyzed. As the esterification, transesterification and polyesterification catalysts, strong mineral acids, such as sulfuric acid, trihydrogenphosphoric acid, and organic are added. sulfoacids such as benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, but notably lead, tin, antimony, manganese, titanium, germanium, molybdenum and the like. This fraction can, however, also be fulfilled by admixtures of metal compounds, especially cobalt, present in the byproduct of the production of cyclohexanol and / or bocyclohexanone, optionally with minor amounts of iron, manganese, titanium, zinc, chromium and other compounds.

Suitable diols for the purposes of the present invention include: ethylene glycol, diethylene glycol, 250038 5 polyglycol, 1-propanediol, 1,4-butanediol, dipropylene glycol, neopentyl glycol, 1,6-hexanediol, diisipropanolamine, and the like.

Triols are mainly trimethylolpropane, glycerol, triethanolamine, propylene oxide and / or ethylene oxide polypropoxylated and / or polyethoxylated trimethylolpropane, similar glycerol and the like. Tetrapolyol to polyol include, but are not limited to, pentaerythritol, dipentaerythritol, byproduct, so-called pentaerythritol, alcoholic, and triethylenepropane syrups, monosaccharides, disaccharides, polysaccharides, especially hydrogenated monosaccharides to polysaccharides, hydrolysed or saponified by polysaccharides , partially saponified polyvinyl acetate, polyvinyl alcohol, partial or complete hydrolyzed or saponified ethylene / vinyl acetate copolymer, and the like. The diol to polyol of the present invention also encompasses "precursors" of diols to polyols such as: ethylene oxide (oxirane), propylene oxide (methyloxirane), epichlorohydrin, C 10 to C 14 alkene oxides, butanediedioxide, cyclopentadiene monoxide, cyclopentadiene dioxide, dicyiclopentadiene amine oxide, dicyclopentadiene dioxide , epoxidized oleic acid and epoxidized unsaturated fats, etc.

The aforementioned and other known direct diol to polyol precursors react mainly analogously as diols to polyols in esterification and polyesterification, and thus the reaction water is not dispensed with, thus eliminating the need to draw larger amounts of water, resulting in an increase in the overall polyester polyol production rate. .

The by-product separated as the organic residue from the hydrolysis of the oxidate after separation of the unconverted cyclohexanone, the main product (cyclohexanone, cyclohexanol) and the portion of the forward organic part and the water is mainly the distillation residue of the hydrolysis column welding machine and / or or cyclohexanol after separation of a substantial portion of the water (e.g., column D 110). This generally has a temperature of 20 ° C of 1 010 to 1115 kg. m ~ 3; water content 4-10% by weight; acid number 150 to 310 mg KOH / g; saponification number 250 to 480 mg KOH / g; bromine number 18 to 55 g Br / 100 g; hydroxyl content of 3.5 to 7.5 wt.

It consists of a mixture of momocarboxylic adicarboxylic acids, hydroxy- and keto-acids, their cyclohexyl esters. Furthermore, lactones are present in monomeric form, but also in dimers and polymers.

Monoicarboxylic acids (butyric, capric, valeric), dicarboxylic acids (succinic, glutaric, adipic) and hydroxyacids (delta-hydroxybutyric acid, delta-hydroxy-valeric acid, hydroxycaproic acid) have been identified. Thereafter, the esters of the foregoing and other acids (cyclohexyl valerate, capricancyclohexyl; dicyclohexyl glutarate; cyclohexyl adipate). In addition, they contain admixtures of cobalt, iron, nickel, titanium and zinc compounds.

This by-product separated as an organic moiety for carrying out the present invention can, if desired, also be pretreated, e.g., by partial hydrogenation, with hydrogen peroxide, chlorine, and the like. alkali metal hypochlorite, adsorbents, by distillation, in particular by distillation under reduced pressure. Many of these processes can also be applied to the final polyester-polyol product.

Additives of one or more of the known dicarboxylic acids or their anhydrides can also be used to carry out the process for producing the polyol polyols of the present invention with the more oxygenated organic product from the production of cyclohexanone and / or cyclohexanol.

The process according to the invention is usually carried out by distilling off the water, in particular the reaction or alcohols, as well as other high-melting points liberated by transesterification under atmospheric or reduced pressure, but can also be carried out under elevated pressure, in the case of a continuous process. In the case of a discontinuous or continuous operation, in particular, if the process is carried out without catalysts.

Removal of water and other high-melting fractions is accomplished by distillation of the off-gas as an azeotrope, especially with added xylene, or other "water", usually in conjunction with a blown gas, generally an inert gas (nitrogen, carbon dioxide, argon), through a drop trap, most commonly through a riser filled with a filler to prevent unwanted abduction of valuable reaction components such as glycols, polyhydric alcohols and the like.

The production process according to the invention can be carried out continuously, semi-continuously, but advantageously, taking into account the fluctuations in the composition of the raw materials mainly in the continuous.

Some other details of the manufacturing process as well as other advantages are apparent from the examples. 2.10038 Example

To a 4-neck esterification flask of a volume of 4 dm 3, with a stirrer, a temperature controller, a riser with a filling temperature of 105 ° C, and 2 530 g of organic residue from the hydrolysis column cooker were weighed with an inert gas inlet cyclohexanone and / or cyclohexanol by cyclohexane oxidation (acid number 267.4 mg KOH / g, saponification number 420.2 mgKOH / g, hydroxyl number 163.4 mg KOH / g, bromine number 27.4 g Br / 100 g) 840 g of ethylene glycol and 840 g of dipentaerythritol are added.

Polyesterifillation and transesterification are carried out with stirring at 200 [deg.] C. for the continuous removal of low molecular weight reaction products from the reaction medium through an inert gas stream for 10 h. 3,450 g of dark colored polyester polyol with an acid value of 0.5 mg are obtained. KOH / g, saponification number 281.2 mg KOH / g, hydroxyl number 435.0 mg KOH / g and viscosity 850 mPaspri at 25 ° C. Example 2

In the procedure described in Example 1, 2,530 g of an organic distillation residue from a hydrolysis column cooker is esterified and re-esterified after removal of a portion of the water, in particular cyclohexanone and / or cyclohexanol by oxidation of cyclohexane in the presence of 840 g of ethylene glycol, 756 g of pemtaerythritol and 84 g of dipentaerythritol for 8 h at 220 ° C. 3,460 g of dark brown phosphorous polyester, polyol having an acidity value of 1.2 mgKOH / g, a saponification number of 285 mg KOH / g and a hydroxyl number of 505 mg KOH / g are obtained.

By the procedure described in Example 1, 425 g of an organic residue from a hydrolyze column of cyclohexanone and / or cyclohexanol by esterification of cyclohexanone in the presence of 141 g of ethylene glycol, 107 g of sucrose at 200 DEG C. are esterified and recrystallized in a 1 dm @ 3 flask. The polyester polyol was obtained with an acid number of 8.45 mg KOH / g, a saponification number of 265.2 mg KOH / g, a hydroxyl number of 307.6 mg KOH / g and a viscosity of 456 mPas at 25 ° C. Example 4

By the procedure described in Example 1, 425 g of an organic residue from the varachydrolysis column was esterified and re-esterified in a 1 dm 3 flask after the removal of the cyclohexanone and / or cyclohexanol by the cyclohexane in the presence of 53 g of pentaerythritol and 53 g of sucrose for 11 h at 200 ° C. A dark polyester polyol having an acid number of 8.7 milligrams KOH / g, a saponification number of 278 milligrams KOH / g, a hydroxyl number of 401.5 milligrams KOH / g and a viscosity of 620 mPas at 25 ° C is obtained. Example 5

Following the procedure described in Example 1, 425 g of an organic residue from a varnish-hydrolysis column of cyclohexanone and / or cyclohexanol by means of cyclo-hexane oxidation at 110-220 ° C in the presence of 141 g of ethylene glycol are esterified and recrystallized in a 1 dm 3 column. 300 g of sucrose molasses production for 13 h. A dark polyester polyol having an acid number of 4.2 mgKOH / g, a saponification number of 270 mg KOH / g, a hydroxyl number of 380 mg KOH / g and a viscosity of 468 mPas is obtained. Example 6

Following the procedure described in Example 1, 425 g of an organic residue from a varnish-hydrolysis column of cyclohexanone and / or cyclohexanol by means of cyclo-hexane and 106 g of adipic acid were esterified and reshaped in a 2 dm 3 column in the presence of 298 g of diethylene glycol, 70 g of pentaerythritol and 70 g of sucrose at 180 ° C for 14 h to give 605 g of a product with an acid value of 4.2 mg KOH / g, a saponification number of 302 mg KOH / g, a hydroxyl number of 430 mg KOH / g and a viscosity of 630 mPas at 25 ° C. A rd e d 7

In the procedure described in Example 1, 425 g of an organic residue from a boiling pot of a hydrolysis column produced by cyclohexanone and / or cyclohexanol by oxidation of cyclohexane in the presence of 140 gylene glycol, 105 g of sucrose and 5 g of an aqueous solution of polyvinyl alcohol are esterified and re-esterified with a 2 dm @ 3 boiling pot column. resp. paraffinized polyvinyl acetate (dry weight 16.5 wt%, viscosity 4% aqueous solution = 12 mPas, acid value 3.8 mgKOH / g, saponification number 132 mg KOH / g, hydroxyl number 13.4 mg KOH / g 570 g of product 0 'acid value 0.9 mg KOH / g, hydrolysis 290 mg KOH / g, hydroxyl number 445 mg KOH / g and viscosity 1.6 mPaspri 25 are obtained. ° C Example 8

Following the procedure described in Example 1, 425 g of the organic residue from the binder of the hydrolysis column of cyclohexanone and / or cyclohexanol by the oxidation of cyclohexanone as specified in Example 1, 120 g of diethylene glycol, 20 g of epichlorohydrin and 130 was esterified and re-esterified with 2 dm 3.

Claims (2)

Process for the production of polyester polyols by esterification and / or esterification and / or polyesterification of organic di-, polyhydroxy compounds with an oxygen by-product of the manufacture of cyclOhexanone and / or cyclohexanol by oxidation of cyclohexane, characterized in that by-product separated as the residue from water vapor scrubbing of the reaction mixture and / or from oxidation of the oxidate after separation of the unconverted cyclohexane, the main product and a portion of the front organic portion and water, optionally with the addition of dicarboxylic acids and / or their anhydrides. 2. A process according to claim 1, wherein the by-product separated as an organic residue has an acid number of 150 to 310 mg KOH / g, preferably 240 to 290 mg KOH / g and a saponification number 250 to 480 mg KOH / g, preferably 380 to 450 milligrams of KOH / g.