CS250038B1 - Method of polyesterpolyols' production - Google Patents

Abstract

Production of polyesterpolyols suitable mainly for the production of polyurethanes esterification, respectively. by transesterification and ρο-esterification in one or two oxygen side organic the product of cyclohexanone production a cyclohexanol by oxidation of cyclohexane, aqueous washing the reaction mixture water vapor in the expansion vessel partially thickening of both the alcohol and the secondary side product separated as organic the residue from the oxidation hydrolysis after separation of the low boilers having an oxygen number of 150 to 310 (240-290 J mg KOH / g and saponification number) 250-480 (380-450 J mg KOH / g). Esterifies, respectively. transesterifies and polyesterifies with at least one diol to polyol (ethylene glycol, diethylene glycol, propylene glycol, polyglycols, pentaerythritol, dipentaerythritol, polyvinyl alcohol and i.J, res, p. their immediate precursor (alkyloxi- ■ rainy, epichlorohydrin).

Description

The present invention relates to a process for the production of polyester polyols from readily available technically available materials, including oxygen-containing petrochemical feedstocks.

Polyesterpolyols are mainly based on acid adipic and divalent to polyvalent alcohols (Korsak, GolOgubov: Izv. Akad. Nauk USSR otd. Chim. 1949, p. 379; U.S. Pat. Nos. 3,010,943, 2,895,926, 2,916,464 and U.S. Pat. Nos. 823,089 and 797,576; Germany Pat. Nos. 1,112,285, 1,166,852 and 1,178,528). NSR pat. no. 1 112285, 1 166 852 and 1178 588).

However, adipic acid is in some cases replaced in part or in full by phthalic acid (U.S. Pat. No. 2,892,813 and No. 2,905,652), or other dicarboxylic acids, such as: succinic, glutaric, pimelic, cork, sebacic, and azelaic (Dobrov EA: Polyurethanes (SNTL Praha 1961; BIOS Final Report No 1 498), linoleic acid. Aromatic acids are used to produce polyols mainly for elastomers, such as by reaction of 1,3-propanediol and 1,4-butanediol with isophthalic acid and terephthalic acid (U.S. Pat. Nos. 1,313,678, 1,323,727 and 1,351,874); the lactones used are mainly s-caprolactone (Ind. Eng. Prod. Res. and Develop. 2, 27 (1963)). In general, a number of individual components are used to produce polyester polyols from dicarboxylic to polycarboxylic acids or their anhydrides and divalent to polyhydric alcohols, depending on the type of raw materials used and the desired properties of the final polyester polyol Gee G .: Trans. Plastic. Inst., London 26, 187 (1958); Mod. Plastic. 35, 9, 145 (1958)].

Polyesterification is carried out with said starting materials as a rule in the presence of an esterification or polyesterification catalyst, respectively. catalyst mixtures, usually at temperatures of 130 to 240 degrees C of atmospheric pressure or slightly elevated, while the reaction water is separated by an inert gas or azeotropic distillation, most often with xylene or another "entrainer". However, non-sufficient sources of dicarboxylic or polycarboxylic acids limit the development of such products.

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

These polyester polyols, despite many obvious technical advantages, do not meet all the requirements for some selected applications and, moreover, the raw material resources for such polyester polyols diminish with a steady increase in the selectivity of p-xylene oxidation to terephthalic acid and dimethyl terephthalate.

The use of secondary oxygen-containing organic compounds from the production of cyclohexanone and / or cyclohexanol by the oxidation of cyclohexane for the production of polyester polyols by esterification and / or esterification and / or polyesterification with diols to tetraols is protected by MS. AO č. 229 429.

The disadvantage of this process is that we use only the distillation residue from the production of cyclohexanone with a high content of dark, yellowish compounds, which in some cases cause technical problems during further processing. For several application purposes, it is therefore necessary to start from separate separate pools of by-products of cyclohexanone production by oxidation of cyclohexane (e.g. the product of DK-109) or to process products with bituminous compounds under altered reaction conditions.

The problem is solved by a process for the production of polyester polyols by esterification and / or esterification and / or polyesterification of organic di- to polyhydroxy compounds with an oxygen-containing organic by-product from the production of cyclohexanone and / or cyclohexanol by oxidation of cyclohexane. the organic residue from the reaction mixture scrubbing with water vapor and / or from the oxidation of the oxidate after separation of the unconverted cyclohexane, the main product and part of the front organic portion and water, optionally with the addition of dicarboxylic acids and / or their anhydrides.

An advantage of the process of the present invention is the significant technical utilization of the by-product mainly from the production of cyclohexanone and cyclohexanol by oxidation of cyclohexane, but for some polyester polyols also by-products from the production of trimethylolpropane and pentaerythritol. Then its flexibility according to the qualitative requirements of the final polyester polyol as well as the availability of other raw material components.

Although the esterification, the transesterification and the polyesterification according to the invention can be carried out without catalysts, it is preferable to carry out the process in a catalytic manner. Suitable esterification, esterification and polyesterification catalysts are strong mineiral acids, such as sulfuric acid, trihydrogenphosphoric acid, and other organic sulfo acids, such as benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, but in particular lead, tin, antimony, antimony, germanium, molybdenum and the like. This fraction can, however, also be admixed with admixtures of metal compounds, in particular cobalt, present in the by-product from the production of cyclohexanol and / or cyclohexanone, possibly with slight additions of amounts of iron, manganese, titanium, zinc, chromium and others.

Suitable diols for carrying out the process according to the invention are:

ethylene glycol, diethylene glycol, polyglycol,

1,2-propanediol,

1,4-butanediol, dipropylene glycol, neopentyl glycol,

1,6-hexanedio-1, diisotpropanolamine aip.

As triols, mainly trimethylolpropane, glycerol, triethanolamine, propylene oxide and / or ethylene oxide polypropoxylated and / or polyethoxylated trimethylolpropane, similar to glycerol and / or p.

Tetrapolyol to polyol are mainly pentaerythritol, dipentaerythritol, a byproduct, so-called. syrups from the production of pentaerythritol, as well as from the production of trimethylolpropane, monosaccharides, disaccharides, polysaccharides, especially hydrogenated monosaccharides to polysaccharides, hydrolyzed or saponified polysaccharides, partially saponified p-olyvinyl acetate, polyvinyl alcohol or polyolinyl alcohol or partially polyol vinyl alcohol or polyol vinyl alcohol or partially polyol vinyl alcohol or polyol vinyl alcohol.

Diols to polyols for carrying out the process of the present invention include the "proximity precursors" of parts to polyols, such as:

ethylene oxide (oxirane), propylene oxide (methyloxirane), epichlorohydrin, C10 to C14 alkene oxides, butanediene dioxide, cyclopentadiene monoxide, cyclopentadiene oxide, dicyclopentadiene monoxide, diclopentadiene dioxide and epoxidized tannic acid and epoxidized tannic acid.

These and other known immediate precursors of diols to polyols react mainly in the esterification and polyesterification analogously to diols to polyols, only the reaction water does not disappear and thus the need to "withdraw" larger amounts of water is eliminated, which ultimately results in an increase in overall polyesterpolyol production rate.

The by-product separated as an organic residue from oxidized hydrolysis after separation of the unconverted cyclohexanone, the main product (cyclohexanone, cyclohexanol) and part of the front organic fraction and water is mainly the distillation residue from the hydrolysis column reboiler of the cyclohexanone and / or cyclohexanol production. (e.g. column D 110). This generally has a density of 1 010 to 1115 kg at 20 ° C. m ~ ³ ; a water content of 4 to 10% by weight;

acid number 150-310 mg KOH / g;

saponification number 250 to 480 mg KOH / g;

bromine number 18 to 55 g Br / 100 g;

content of -hydroxyl groups 3.5 to 7.5 wt.

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

Monocarboxylic acids (butyric, caproic, valeric), dicarboxylic acids (succinic, glutaric, adipic) and hydroxy acids (delta-hydroxybutyric acid, delta-hydroxyvaleric acid, hydroxycaproic acid) were identified. Then, esters of the aforementioned and other acids (cyclohexyl valerate, cyclohexyl caproate; dicyclohexyl glutarate; cyclohexyl adipane). In addition, they contain admixtures of cobalt, iron, nickel, titanium and zinc compounds.

This by-product separated as an organic residue for carrying out the process of the invention can also be pre-purified if desired, e.g. partial hydrogenation, deposition of hydrogen peroxide, chlorine, resp. alkali metal hypochlorite, adsorbents, by distillation, in particular by film distillation under reduced pressure. Many of these processes can also be applied to purify the end product, polyester polyol.

Additives of one or more known dicarboxylic acids or their anhydrides can also be used to carry out the process for producing the polyester polyols according to the invention in addition to the oxygen-containing organic by-product from the production of cyclohexanone and / or cyiclohexanol.

The process according to the invention is usually carried out by distilling off water, in particular reaction, optionally alcohols and other high-volatile fractions released by transesterification at atmospheric or reduced pressure, but can also be carried out at elevated pressure, in particular in the case of continuous operation. In the case of a discontinuous or semi-continuous process, in particular if the process is carried out without catalysts.

Separation of water and other high volatiles is accomplished by distilling off as azeotrope, in particular with added xylene or other "water", usually also with the aid of a blown gas, usually inert gas (nitrogen, carbon dioxide, argon), via a drip catcher, preferably through a riser filled with a charge so as 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 a differently defined variation in the composition of the raw materials, mainly discontinuously.

Some other details of the production method as well as other advantages are evident from the examples.

280038

EXAMPLE

To a 4-necked 4 dm ³ esterification flask equipped with a stirrer, a temperature controller, a 105 ° C temperature riser and an inert gas inlet was weighed 2530 g of the residue from the hydrolysis column of the cyclohexanone and / or cyclohexanol production plant. acidity 267.4 mg KOH / g, saponification number 420.2 mg KOH / g, hydroxyl value 163.4 mg KOH / g, bromine number 27.4 g Br / 100 g) are added 840 grams of ethylene glycol and 840 g of dipentaerythritol.

The polyester esterification and transesterification is carried out with stirring at 200 ° C with continuous removal of low molecular weight reaction products from the reaction medium by a stream of inert gas for 10 h. 3450 g of a dark-colored polyester polyol having an acid number of 0.5 mg KOH / g, a saponification number of 281.2 mg KOH / g, a hydroxyl number of 435.0 mg KOH / g and a viscosity of 850 mPas at 25 [deg.] C. are obtained.

Example 2

According to the procedure described in Example 1, 2530 g of organic distillate residue from the hydrolysis column boil are esterified and re-esterified after removal of part of the water from the cyclohexanone and / or cyclohexanol production plant by oxidation of cyclohexane in 840 g ethylene glycol, 756 g pentaerythritol and 84 g dipentaerythritol. 220 DEG. 3460 g of a dark-brown polyester polyester having an acid number of 1.2 mg KOH / g, a saponification number of 285 mg KOH / g and a hydroxyl number of 505 mg KOH / g are obtained. Example 3

In a 1 dm ³ flask as described in Example 1, 425 g of organic residue from the hydrolysis column boiling plant of cyclohexanone and / or cyclohexanol are esterified and re-esterified by oxidation of cyclohexanone in the presence of 141 g of ethylene glycol, 107 g of sucrose at 200 ° C for 11 h . A polyester polyol having an acid number of 8.45 mg KOH / g, a saponification number of 265.2 mg KOH / g, a hydroxyl value of 307.6 mg KOH / g and a viscosity of 456 mPas at 25 ° C is obtained.

Example 4

As described in Example 1, 425 g of organic residue from the hydrolysis column boil is esterified and re-esterified in a 1 dm ³ flask after removing some of the water from the cyclohexanone and / or cyclohexanol production plant by oxidizing cyclohexane in the presence of 53 g of pentaerythritol and 53 g of sucrose. temperature 200 ° C. A dark polyester polyol is obtained with an acid number of 8.7 milligrams of KOH / g, a saponification number of 278 milligrams of KOH / g, a hydroxyl value of 401.5 milligrams of KOH / g and a viscosity of 620 mPas at 25 ° C.

Example 5

As described in Example 1 in a flask 1 ^dm3 esterified and re-esterified 425 g of the organic residue from the digester hydrolysis column production of cyclohexanone and / or cyclohexanol by oxidation of cyclohexane at 110 to 220 DEG C. in the presence of 141 g of ethylene glycol and 300 g of molasses production sucrose for 13 h. A dark polyester polyol having an acid number of 4.2 mg KOH / 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

In a 2 dm ³ flask as described in Example 1, 425 g of organic residue from the hydrolysis column boiling plant of cyclohexanone and / or cyclohexanol are esterified and re-esterified by oxidation of cyiclohexane and 106 g of adipic acid in the presence of 298 g of diethylene glycol, 70 g of pentaerythritol and 70 g. of sucrose at 180 ° C for 14 h. 605 g of product are obtained with an acid number 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.

Example (k Ί a d 7

As described in Example 1 in a four-necked flask 2 ^dm3 esterified and re-esterified 425 g of the organic residue from the digester hydrolysis column production of cyclohexanone and / or cyclohexanol by oxidation of cyclohexane in the presence of 140 g of ethylene glycol, 105 g of sucrose and 5 g of an aqueous flowable polyvinyl alcohol, or . partially saponified polyvinyl acetate (dry matter 16.5% by weight, 4% aqueous solution viscosity = 12 mPas, acid value 3.8 mg KOH / g, saponification number 132 mg KOH / g, hydroxyl value 13.4 mg KOH / g at temperature 200 ° C for 12 h. 570 g of product 0 'were obtained with an acid number of 0.9 mg KOH / g, a saponification number of 290 mg KOH / g, a hydroxyl number of 445 mg KOH / g and a viscosity of 1.6 mPas at 25 ° C.

Example 8

In a 2 dm ³ flask as described in Example 1, 425 g of the organic residue from the hydrolysis column boiling plant of cyclohexanone and / or cyclohexanol are esterified and re-esterified by oxidizing the cyclohexanone specified in Example 1, 120 g diethylene glycol, 20 g epichlorohydrin and 130 g.

O r * Π

Χτι Í-. ití ί η »

Three grams of dipentaerythritol. The esterification is carried out at 210 ° C for 10 h. 480 g of product are obtained with an acid number of 2.8 mg KOH / g, a saponification number of 315 mg KOH / g, a hydroxyl number of 85 mg KOH / g and a viscosity of 320 mPas at 25 ° C.

Example 9

The preparation of the polyester polyol is carried out in a 1 dm ³ flask as described in Example 1. The acidic component used is the aqueous fraction of the scrubbing of the reaction mixture after oxidation of cyclohexane with water, in an expansion vessel, after partial concentration. Then 500 g of this by-product (water content 18.6% by weight, acid value 305 mg KOH / g, content of esters and other compounds 32.1% by weight, hydroxyl value 106 mg KOH / g) are esterified, polyesterified and partly re-esterified with a mixture of 152 g of ethylene glycol and 112 g of pentaerythritol at 200 ° C for 8 h. A polyester polyol having an acid number of 2.8 mg KOH / g, a hydroxyl number of 536.3 mg KOH / g, a saponification number of 326 mg KOH / g and a dynamic viscosity of 695 mPas / 25 ° C is obtained.

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.