Process for the preparation of low molecular weight polyhydroxyl compounds

The instant invention relates to an improved process for the preparation of low molecular weight polyalcohols by the catalytic hydrogenation of a mixture of different low molecular weight hydroxy aldehydes, hydroxy ketones and optionally also polyhydric alcohols such as is formed from the autocondensation of formaldehyde (such a mixture will hereinafter be referred to as "formose"). The invention also relates to the use of these polyalcohols for the production of polyurethane resins.

BACKGROUND OF THE INVENTION 
It has been known since the work by Butlerow and Loew (Ann. 120, 295 (1861) 
and J. prakt. Chem. 33, 321 (1886) in the previous century that the 
autocondensation of formaldehyde hydrate (formose synthesis) in the 
presence of basic compounds such as calcium or lead hydroxide is 
accompanied by the formation of hydroxy aldehydes and hydroxy ketones. 
Work on formose synthesis has repeatedly been carried out since then. 
In this connection one may refer, for example, to Pfeil, Chem. Berichte 84, 
229 (1951); Pfeil and Schroth, Chemische Berichte 85, 303 (1952); R. D. 
Partridge and A. H. Weiss. Carbohydrate Research 24, 29-44 (1972); the 
formoses obtained from glyceraldehyde and dihydroxy acetone according to 
Emil Fischer; German Pat. Nos. 822,385; 830,951 and 884,791, U.S. Pat. 
Nos. 2,121,981; 2,224,910; 2,692,935 and 2,272,378 and British Pat. No. 
513,708. These known processes have certain disadvantages such as poor 
volume/time yields and, colored by-products. New processes have recently 
been developed by which virtually colorless formoses free from undesirable 
by-products can be prepared in high yields with the aid of conventional 
catalysts. 
One of these new processes consists of carrying out the condensation of 
formaldehyde hydrate in the presence of catalysts consisting of soluble or 
insoluble lead (II) salts or of lead (II) ions attached to high molecular 
weight carriers and in the presence of a cocatalyst which consists of a 
mixture of hydroxy aldehydes and hydroxy ketones which may be obtained 
from the condensation of formaldehyde hydrate and is characterized by the 
following molar ratios: 
compounds with 3 C atoms/compounds with 4 C atoms: 0.5 to 2.0; 
compounds with 4 C atoms/compounds with 5 C atoms: 0.2 to 2.0; 
compounds with 5 C atoms/compounds with 6 C atoms: 0.5 to 5.0; 
and in which the proportion of components containing from 3 to 6 carbon 
atoms is at least 75% by weight, preferably more than 85% by weight, based 
on the total quantity of cocatalyst. 
The reaction temperature is generally between 70.degree. and 110.degree. 
C., preferably between 80.degree. and 100.degree. C., and the pH of the 
reaction solution is adjusted by controlled addition of an inorganic or 
organic base, first to 6.0 to 8.0, preferably 6.5 to 7.0 up to a 
conversion of 10 to 60%, preferably 30 to 50%, and thereafter to 4.0 to 
6.0, preferably 5.0 to 6.0. It is surprisingly found that the proportions 
of products in the mixture of polyols, hydroxy aldehydes and hydroxy 
ketones can be varied in a reproducible manner by this special control of 
the pH followed by cooling at different residual formaldehyde contents (0 
to 10% by weight, preferably 0.5 to 6% by weight). 
When the autocondensation of formaldehyde hydrate has been stopped by 
cooling and/or by inactivation of the lead catalyst with acids, the 
catalyst, and optionally also the water contained in the products, is 
removed. Further details of this procedure may be found in German 
Offenlegungsschriften Nos. 2,639,084 and 2,732,077. 
According to German Offenlegungsschrift No. 2,714,084, highly concentrated 
colorless formoses may also be produced with high volume/time yields by 
condensing aqueous formalin solutions and/or paraformaldehyde dispersions 
in the presence of a soluble or insoluble metal catalyst and in the 
presence of a co-catalyst which has been prepared by partial oxidation of 
a dihydric or higher hydric alcohol which contains at least two adjacent 
hydroxyl groups and has a molecular weight of from 62 to 242 or a mixture 
of such alcohols. The pH of the reaction solution is controlled by 
controlled addition of a base so that it is maintained at 6.0 to 9.0 until 
conversion is 5 to 40% complete and is then adjusted to a value from 4.5 
to 8.0 until the condensation reaction is stopped so that in this phase of 
the reaction it is lower by 1.0 to 2.0 units than in the first reaction 
phase. The reaction is then stopped by inactivation of the catalyst when 
the residual formaldehyde content is from 0 to 10% by weight, and the 
catalyst is removed. 
High quality formoses can also be prepared by the condensation of 
formaldehyde in the presence of a metal catalyst and more than 10% by 
weight, based on formaldehyde, of one or more dihydric or higher hydric 
low molecular weight alcohols and/or relatively high molecular weight 
polyhydroxyl compounds (see German Offenlegungsschrift No. 2,714,104). 
According to another process, it is particularly economical to prepare 
formose directly from formaldehyde-containing synthesis gases, i.e. 
without first preparing aqueous formalin solutions or paraformaldehyde. 
For this purpose, the synthesis gases such as can be obtained from the 
large scale industrial production of formaldehyde are conducted 
continuously or intermittently at temperatures of from 10.degree. to 
150.degree. C. into an absorption liquid which consists of water, 
monohydric or polyhydric low molecular weight alcohols and/or relatively 
high molecular weight polyhydroxyl compounds and/or compounds capable of 
enediol formation as co-catalyst and/or soluble or insoluble metal 
compounds as catalyst, optionally bound to a high molecular weight 
carrier, which absorption liquid is at a pH of from 3 to 10. A 
formaldehyde is directly condensed in situ in the absorption liquid 
(optionally also in a reaction tube or cascade of stirrer vessels 
following the container for the absorption liquid), and autocondensation 
of the formaldehyde is stopped by cooling and/or by inactivation of the 
catalyst with acids when the residual formaldehyde content in the reaction 
mixture is from 0 to 10% by weight. The catalyst is finally removed. 
For some purposes, mixtures of hydroxy aldehydes, hydroxy ketones and 
optionally polyalcohols of the kind obtained by the processes described 
above or by processes known in the art are required to be converted into 
mixtures of polyalcohols by reduction of the carbonyl group. Such polyol 
mixtures obtained by the reduction of formoses will hereinafter be 
referred to as "formite". It is possible for example, to reduce formose 
with sodium borohydride from aqueous solution at room temperature (see R. 
D. Partridge, A. H. Weiss and D. Todd, Carbohydrate Research 24 (1972), 
42); but reduction of formose may also be carried out electrochemically, 
for example. 
Many processes are already known for the catalytic hydrogenation of sugars 
and of formose. Widely differing quantities and types of catalysts are 
employed, depending on the process. Thus L. Orthner and E. Gerisch 
Biochem. Zeitung 259, 30 (1933), for example, describe a process for the 
catalytic hydrogenation of formose in which a 4% aqueous solution of 
formose is hydrogenated with 170% by weight, based on the quantity of 
formose, of Raney nickel by a reaction carried out for 7 to 8 hours at 
130.degree. C. under a hydrogen pressure of 120 bar. Such a process is, of 
course, economically unsatisfactory in every aspect. In U.S. Pat. No. 
2,269,935, a process has been disclosed in which a solution containing 
approximately 40% by weight of formose is hydrogenated at an acid pH with 
20% by weight of nickel catalyst at a hydrogen pressure of 600 to 620 bar 
and at 120.degree. C. The disadvantage of this variation of the process 
lies not only in the high operating pressure but also in the low pH, which 
results in products which are colored green by nickel ions. 
In U.S. Pat. No. 2,224,910 a process has been disclosed for the 
hydrogenation of formose, in which a 40% formose solution is hydrogenated 
with 30% by weight of Raney nickel, based on the quantity of formose, at a 
hydrogen pressure of 140 to 210 bar and pH 7 for 4 hours. This process is 
also unsatisfactory because of the large amount of catalyst required and 
the long reaction time. 
Other hydrogenation processes have been described in German Pat. Nos. 
705,274; 725,842; 830,951; 888,096 and 1,004,157 and in U.S. Pat. Nos. 
2,271,083; 2,272,378; 2,276,192; 2,760,983 and 2,775,621. All of these 
processes, however, have one or more of the following disadvantages: 
considerable outlay in apparatus and difficulty of handling owing to the 
high hydrogen pressures; large consumption of catalyst, based on the 
quantity of hydrogenated product (10 to 200% by weight): discolored 
products due to long hydrogenation times (1 to 10 hours). 
Common to all of the known processes is the use of metal catalysts and in 
some cases noble metal catalysts. Raney nickel, which is commonly used, 
develops its full activity only in the alkaline range. However, since 
formoses have a strong tendency to caramelize and give rise to severely 
discolored products in an alkaline medium, the processes known in the art 
are generally carried out at a slightly acid or neutral pH. 
It was therefore an object of the present invention to provide a process 
for the rapid hydrogenation of formose with little capital expenditure and 
very small quantities of catalyst. 
DESCRIPTION OF THE INVENTION 
It has now surprisingly been found that, contrary to the view hitherto held 
in the literature, formoses which may be mixed with other natural or 
synthetic sugars, can be rapidly hydrogenated to colorless polyol mixtures 
in an alkaline medium with only small quantities of catalyst, at hydrogen 
pressures of from 100 to 200 bar and temperatures of from 50.degree. to 
250.degree. C. This is new and in view of the above-mentioned 
caramelization reactions of formose, which take place particularly rapidly 
in an alkaline medium at elevated temperatures, it is also completely 
unexpected. One would indeed have expected dark colored to black products 
to be produced. 
It must also be regarded as surprising that in the polyalcohol mixtures 
obtained by the process according to the invention, the proportion of low 
molecular weight C.sub.2 -, C.sub.3 - and C.sub.4 -alcohols is 
substantially higher than in formites produced by conventional processes. 
This is particularly advantageous for various applications. 
The present invention thus relates to a process for the preparation of low 
molecular weight, polyhydric alcohols by the reduction of formose at a 
temperature of from 80.degree. to 220.degree. C. under a hydrogen pressure 
of from 50 to 300 bar in the presence of a metal catalyst, in which 
process 
(1) a solution of formose at a concentration of at least 20%, preferably 
more than 35% and most preferably more than 45% is introduced batchwise 
into a reactor maintained at a temperature of from 100.degree. to 
200.degree. C., most preferably at 140.degree. to 190.degree. C., in such 
an amount that the proportion of reducible groups, determined as carbonyl 
groups, in the product mixture contained in the reactor does not exceed 2% 
by weight and preferably does not exceed 1% by weight and most preferably 
not 0.5% by weight; 
(2) the pH is adjusted to a value in the range of from 7.5 to 12.5, 
preferably from 8.5 to 11.5, immediately before the hydrogenation 
reaction; 
(3) the total quantity of catalyst used is from 10.sup.-4 to 
5.times.10.sup.-2 % by weight, based on the total quantity of starting 
material which is to be reduced, the catalyst content remaining constant 
in the reactor; 
(4) the reaction product is withdrawn batchwise from the reactor when the 
proportion of reducible groups, determined as carbonyl groups, has fallen 
below 0.15% by weight, and preferably below 0.05% by weight. 
The process according to the invention is advantageously carried out as 
follows: 
The quantity of catalyst, preferably Raney nickel, required for the 
hydrogenation of the entire batch is introduced into water in a pressure 
reactor. The reactor is filled with gaseous hydrogen to the operating 
pressure of 50 to 300 bar and then heated to the hydrogenation temperature 
of from 80.degree. to 220.degree. C. From three to thirty times the 
quantity, preferably five to twenty times, of formose solution, based on 
the catalyst, is then slowly pumped in (i.e. about 1/6th of the capacity 
of the reactor) within 3 minutes to 2 hours, preferably 5 to 30 minutes. 
Hydrogenation is then continued for a period ranging from half to four 
times the time which was required for pumping in the solution. The 
quantity of reaction mixture corresponding to the quantity of formose 
solution pumped in is then forced out through a steel-jacketed frit while 
the catalyst is left in the reactor. A new batch is then pumped into the 
reactor and treated in the same way as the first batch. All subsequent 
batches are treated in the same manner. 
This batchwise hydrogenation by pumping according to the invention results 
in an extremely long catalyst life and hence, based on the total quantity 
of formose which is reduced or to be reduced, very low catalyst 
consumption. 
In this connection, it should be pointed out again that the long catalyst 
life which can be achieved according to the invention is completely 
surprising since, in view of the caramelization reactions of formose which 
would be expected to take place in an alkaline medium, it would be 
expected that the catalyst would be inactivated by the products. 
The process according to the invention for production of hydrogenated 
sugars or hydrogenated formose ("formite") affords the following important 
advantages over the known art: 
1. The process according to the invention is highly economical. Compared 
with all known processes, it requires an extremely small amount of 
catalyst. The hydrogenation velocity is very high; for example, only 10 to 
15 minutes are required for each hydrogenation step at high temperatures 
(150.degree. to 190.degree. C.). 
2. The process according to the invention can be carried out without great 
capital outlay since, in view of the relatively low pressures employed, no 
special apparatus or safety measures are necessary. 
3. The process according to the invention results in light colored or 
colorless products which can be used for a wide variety of purposes 
without further purification. 
4. One surprising and special advantage of the process is the substantial 
splitting of the starting materials into low molecular C.sub.2 - to 
C.sub.5 -alcohols, whereby the viscosity of the polyhydroxyl compounds is 
lowered, their processibility is improved and at the same time their 
compatibility with other substances is increased, especially with the 
starting components used for the production of synthetic resins by the 
polyisocyanate polyaddition process (in particular higher molecular weight 
polyhydroxyl compounds and blowing agents). 
5. Another special advantage is that, if desired, other compounds. e.g. 
alkanals, alcohols (e.g. C.sub.1 to C.sub.23, in particular C.sub.1 to 
C.sub.8 alcohols, which may be either monohydric or polyhydric), ketones, 
aldehydes or higher molecular weight polyols may be present during 
hydrogenation, particularly because they improve the compatibility of the 
reaction products with the blowing agents used for the polyisocyanate 
polyaddition process. These aldehydes, ketones and alkanals may be added 
in quantities of up to 50% by weight (based on the total quantity of 
substances which are to be reduced). 
6. Not only formose but other natural and synthetic sugars may also be 
hydrogenated by the process according to the invention. 
The aldehydes or alkanals which may also be used in the process according 
to the invention include in particular acetaldehyde, propionaldehyde, 
butyraldehyde, isobutyraldehyde and their methylol derivatives. 
The ketones used may be acetone, methylethyl ketone, diethyl ketone, 
cyclopentanone, cyclohexanone, mesityloxide, isophorone, acetophenone, 
benzophenone and their methylol derivatives. 
The solvent used in the process according to the invention is mainly water 
although the formoses may be dissolved in any monohydric or polyhydric 
alcohols. Examples of suitable alcohols include methanol; ethanol; 
propanol; butanol; isopropanol; isobutanol; cyclopentanol; cyclohexanol; 
2-ethoxy-ethanol; 2-propoxyethanol; b 2-isopropoxyethanol; 
2-butoxy-ethanol; 2-(2-methoxyethoxy)-ethanol; 2-(2-ethoxyethoxy)-ethanol; 
1,2-bis-(2-hydroxyethoxy)-ethane; ethylene glycol, diethylene glycol; 
triethylene glycol; tetraethylene glycol; 1,2-propanediol; isopropylene 
glycol; 1,3-propanediol; 1,2-butanediol; 1,3-butanediol; 
2-methoxy-1-butanol; 2,3-butane-diol; 1,5-pentanediol; 
2,2-dimethyl-1,3-propanediol; 1,6-hexanediol; 2,5-hexanediol; 
2-methyl-2,4-pentanediol; 3-methyl-1,5-pentanediol; 
3-methyl-2,4-pentanediol; 2,3-dimethyl-2,3-butanediol; 
2-methyl-2-propyl-1,3-propanediol; 2,2-diethyl-1,3-propanediol; 
2-ethyl-1,3-hexanediol; 2,5-dimethyl-2,5-hexanediol; 
2,2,4-trimethyl-1,3-pentanediol; 1,3-diethoxy-2-propanol; 
2-hydroxymethyl-2-methyl-1,3-propanediol; 1,2,6-hexanetriol; 
2-ethyl-2-hydroxymethyl-1,3-propanediol; 
2,2-bis-hydroxymethyl-1,3-propanediol; erythritol; quinitol; mannitol; 
sorbitol; methyl glycoside and ethoxylation and propoxylation products of 
these alcohols with a molecular weight of up to about 400 and, of course, 
also mixtures of these alcohols. Ethylene glycol, glycerol and 
1,4-butanediol are particularly preferred. 
According to the invention, polyhydroxyl compounds having a molecular 
weight of from 400 to 10,000, preferably from 500 to 6,000, may also be 
used for the hydrogenation of formose, optionally as mixtures with the 
above mentioned alcohols. These polyhydroxyl compounds are preferably also 
liquid at room temperature or soluble in the formose solution. For 
example, the polyesters, polyethers, polythioethers, polyacetals, 
polycarbonates and polyester amides containing at least 2, generally from 
2 to 8, preferably from 2 to 4 hydroxyl groups, of the type commonly used 
for the production of homogeneous and cellular polyurethanes may be used. 
The hydrogenation process according to the invention is applicable to any 
formoses obtained by the known processes described above. The formose may 
also be used as a mixture with up to 80% by weight, based on the total 
quantity of compounds to be hydrogenated, of other artificial or natural 
sugars, e.g. glucose, maltose, fructose, saccharose, lactose, etc. One 
advantage of formose used in such mixtures is that it is an excellent 
solvent or solubilizing agent for such sugars. 
The artificial invert sugars which may also be used according to the 
invention may be hydrolysates of any di- and/or polysaccharides e.g. 
hydrolysates of cane sugar, mixtures of cane sugar and invert sugars, 
hydrolysates of trehalose, maltose or isomaltose, hydrolysates of corn and 
potato starch and of pectins (amylose and amylopectins), cellobiose and 
lactose, hydrolystates of galactose, glucose mixtures, raffinose 
hydrolysates, cellulose hydrolysates, hydrolysates of dextrins optionally 
mixed with unhydrolyzed dextrins, hydrolysates of Schardinger dextrins 
(cyclic dextrins) hydrolysates of glycogen, hydrolysates of 
glucose-6-phosphoric acid, hydrolysates of glucose-1-phosphate 
(coriesters), fructose-6-phosphate, degraded pectins (polygalacturonic 
acids), degraded glucosamines and hydrolysates of molasses residues, etc. 
The pH of the solution which is to be hydrogenated may be adjusted with 
either inorganic or organic bases. Sodium hydroxide, potassium hydroxide, 
calcium hydroxide, magnesium hydroxide, barium hydroxide, aluminum 
hydroxide, triethylamine, N-methyl morpholine and N-methyl piperidine are 
preferably used. It is particularly preferred to use the base which has 
been used for the synthesis of the formose and which has been converted 
into the free OH form before hydrogenation by treatment of the formose 
solution with the ion exchange resin in the OH form. In that case, the 
formose solution automatically adjusts itself to the required alkalinity. 
The hydrogenation catalysts used for the process according to the invention 
are mainly metals with atomic numbers 23 to 29, in the elementary and/or 
oxidic form. Suitable catalysts include, for example, those based on 
nickel or cobalt. As carriers for the catalysts there may be used both 
inorganic materials such as Kieselguhr, silicates, aluminum oxides, alkali 
metal and alkaline earth metal silicates, aluminum silicates, 
montmorillonite, zeolithes, spinells, dolomite, kaolin, magnesium 
silicates, zirconium oxide, iron oxide, zinc oxide, calcium carbonate, 
silicon carbide, aluminum phosphate, boron phosphate, asbestos or active 
charcoal and organic materials such as naturally occurring or synthetic 
high molecular weight compounds such as silk, polyamides, polystyrenes, 
cellulose or polyurethanes. The carrier may be in the form of pellets, 
strands, filaments, cylindrical shapes, polygons or powders. It is 
preferred to use Raney-type catalysts such as Raney-nickel, W-1-, W-5-, 
W-6- and W-7-Raney nickel (see H. Adkins, J. Am. Chem. Soc. 69, 3039 
(1974)), Raney-cobalt catalysts, Raney-copper, Raney-nickel-iron, 
Raney-cobalt-nickel and Raney-cobalt-iron. Metal catalysts obtained by the 
reduction of nickel or cobalt salts may also be used; for example, 
urushibara nickel, nickel or cobalt salts which have been reduced with 
metal alkyl compounds, alkali metal hydrides, hydrazines, boranates or 
hydrogen boride, catalysts prepared by the reduction of metal oxides or 
metal oxide mixtures, or the metal oxides or metal oxide mixtures 
themselves. 
The preferred catalysts according to the invention, which are based on 
metals with atomic numbers 23 to 29, may contain up to 10% by weight of 
one or more of the following elements as accelerators: Li, Na, Ca, Ba, K, 
Ag, Be, La, Ce, V, Nb, Ta, Mo, W, and up to 1% by weight of the elements 
Ru, Rh, Pd, Au, Ir, and Pt. 
Raney nickel containing 90% by weight of Ni and &lt;1% by weight of Fe, Ca and 
Na, Raney nickel iron containing from 5 to 30% by weight of Fe and &lt;1% by 
weight of Ca and Na, and Raney cobalt-iron containing from 10-30% by 
weight of Fe are particularly suitable catalysts. 
The mixtures of polyhydric low molecular weight alcohols prepared according 
to the invention are most preferably used as polyol components for the 
polyisocyanate polyaddition process. 
The present invention thus also relates to a process for the preparation of 
cellular or non-cellular polyurethane resins by the reaction of 
(a) a polyisocyanate with 
(b) a compound with a molecular weight of from 32 to 400 which contains at 
least two active hydrogen atoms, optionally 
(c) a compound with a molecular weight of from 400 to 10,000 containing at 
least two active hydrogen atoms, and optionally 
(d) blowing agents, catalysts and other known additives, which process is 
characterized in that component (b) consists entirely or partly of a 
mixture of low molecular weight polyhydric alcohols prepared according to 
the invention. 
The polyisocyanates used as starting components according to the invention 
may be aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic 
polyisocyanates such as those described, for example, by W. Siefken in 
Justus Liebigs Annalen der Chemie, 562, pages 75 to 136. Examples include 
ethylene diisocyanate; tetramethylene-1,4-diisocyanate; 
hexamethylene-1,6-diisocyanate; dodecane-1,12-diisocyanate; 
cyclobutane-1,3-diisocyanate; cyclohexane-1,3- and -1,4-diisocyanate and 
any mixtures of these isomers; 
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (German 
Auslegeschrift No. 1,202,785 and U.S. Pat. No. 3,401,190); 
hexahydrotolylene-2,4-diisocyanate and -2,6-diisocyanate and any mixtures 
of these isomers; hexahydrophenylene-1,3-diisocyanate and/or 
1,4-diisocyanate; perhydrodiphenylmethane-2,4'-diisocyanate and/or 
4,4'-diisocyanate; phenylene-1,3-diisocyanate and -1,4-diisocyanate; 
tolylene-2,4-diisocyanate and -2,6-diisocyanate and any mixtures of these 
isomers; diphenylmethane-2,4'-diisocyanate and/or 4,4'-diisocyanate; 
naphthylene-1,5-diisocyanate; triphenylmethane-4,4',4"-triisocyanate; 
polyphenyl-polymethylene polyisocyanates which can be obtained by 
aniline-formaldehyde condensation followed by phosgenation and which have 
been described, for example in British Pat. Nos. 874,430 and 848,671; m- 
and p-isocyanatophenyl-sulphonyl isocyanates as described in U.S. Pat. No. 
3,454,606; perchlorinated aryl polyisocyanates such as those described in 
U.S. Pat. No. 3,277,138; polyisocyanates having carbodiimide groups as 
described in U.S. Pat. No. 3,152,162; diisocyanates of the kind described 
in U.S. Pat. No. 3,492,330; polyisocyanates with allophanate groups as 
described e.g. in British Pat. No. 994,890, Belgian Pat. No. 761,626 and 
published Dutch Patent Application No. 7,102,524; polyisocyanates with 
isocyanurate groups, e.g. as described in U.S. Pat. No. 3,001,973, German 
Pat. Nos. 1,022,789; 1,222,067 and 1,027,394 and German 
Offenlegungsschriften Nos. 1,929,034 and 2,004,048; polyisocyanates with 
urethane groups as described e.g. in Belgian Pat. No. 752,261 or U.S. Pat. 
No. 3,394,164; polyisocyanates with acylated urea groups as described in 
German Pat. No. 1,230,778; polyisocyanates with biuret groups as described 
e.g. in German Pat. No. 1,101,394; U.S. Pat. Nos. 3,124,605 and 3,301,372 
and British Pat. No. 889,050; polyisocyanates prepared by telomerization 
reactions as described for example, in U.S. Pat. No. 3,654,106; 
polyisocyanates containing ester groups, such as those described, for 
example, in British Pat. Nos. 965,474, and 1,072,956; U.S. Pat. No. 
3,567,763 and German Pat. No. 1,231,688; reaction products of the above 
mentioned isocyanates with acetals as described in German Pat. No. 
1,072,385; and polyisocyanates containing polymeric fatty acid groups as 
described in U.S. Pat. No. 3,455,883. 
The distillation residues obtained from the commercial production of 
isocyanates and still containing isocyanate groups may also be used, 
optionally as solutions in one or more of the above mentioned 
polyisocyanates. Any mixtures of the above mentioned polyisocyanates may 
also be used. 
As a general rule, it is particularly preferred to use readily available 
polyisocyanates such as tolylene-2,4-diisocyanate and -2,6-diisocyanate 
and any mixtures of these isomers ("TDI"); polyphenyl-polymethylene 
polyisocyanates of the kind which can be prepared by aniline-formaldehyde 
condensation followed by phosgenation ("crude MDI"); and polyisocyanates 
containing carbodiimide groups, urethane groups, allophanate groups, 
isocyanurate groups, urea groups, or biuret groups ("modified 
polyisocyanates"). 
The starting components used according to the invention may also include 
compounds with a molecular weight of generally 400 to 10,000, which 
contain at least two isocyanate-reactive hydrogen atoms. These compounds 
may contain amino groups, thiol groups or carboxyl groups but are 
preferably polyhydroxyl compounds, and in particular compounds having from 
two to eight hydroxyl groups. Especially preferred are polyhydroxyl 
compounds having molecular weights of from 800 to 10,000, preferably 1,000 
to 6,000, e.g. polyesters, polyethers, polythioethers, polyacetals, 
polycarbonates and polyester amides containing at least two, generally two 
to eight, but preferably two to four hydroxyl groups, of the kind which 
are generally known for the production of both homogeneous and cellular 
polyurethanes. 
Suitable polyesters with hydroxyl groups include e.g. reaction products of 
polyhydric, and preferably dihydric alcohols (to which trihydric alcohols 
may be added) and polybasic, preferably dibasic, carboxylic acids. Instead 
of free polycarboxylic acids, the corresponding polycarboxylic acid 
anhydrides or corresponding polycarboxylic acid esters of lower alcohols 
or mixtures thereof may, of course, be used for preparing the polyesters. 
The polycarboxylic acids may be aliphatic, cycloaliphatic, aromatic and/or 
heterocyclic and they may be substituted, e.g. by halogen atoms, and/or 
unsaturated. 
The following are mentioned as examples: Succinic acid; adipic acid; 
suberic acid; azelaic acid; sebacic acid; phthalic acid; isophthalic acid; 
trimellitic acid; phthalic acid anhydride; tetrahydrophthalic acid 
anhydride; hexahydrophthalic acid anhydride; tetrachlorophthalic acid 
anhydride; endomethylene tetrahydrophthalic acid anhydride; glutaric acid 
anhydride; maleic acid; maleic acid anhydride; fumaric acid; dimeric and 
trimeric fatty acids such as oleic acid which may be mixed with monomeric 
fatty acids; dimethyl terephthalate and terephthalic acid-bis-glycol 
esters. The following are examples of suitable polyhydric alcohols: 
Ethylene glycol; propylene glycol-(1,2) and -(1,3); butylene glycol-(1,4) 
and -(2,3); hexanediol-(1,6); octanediol-(1,8); neopentylglycol; 
cyclohexanediol methanol (1,4-bis-hydroxymethylcyclohexane); 
2-methyl-1,3-propanediol; glycerol; trimethylolpropane; 
hexanetriol-(1,2,6); butanetriol-(1,2,4); trimethylolethane; 
pentaerythritol; quinitol; mannitol and sorbitol; methyl glycoside; 
diethylene glycol; triethylene glycol; tetraethylene glycol; polyethylene 
glycols; dipropylene glycol; polypropylene glycols; dibutylene glycol and 
polybutylene glycols. The polyesters may also contain a proportion of 
carboxyl end groups. Polyesters of lactones such as .epsilon.-caprolactone 
or hydroxycarboxylic acids such as .omega.-hydroxycaproic acid may also be 
used. 
The polyethers used according to the invention which have at least two, 
generally two to eight and preferably two or three hydroxyl groups are 
also known per se and are prepared, for example, by polymerization of 
epoxides such as ethylene oxide, propylene oxide, butylene oxide, 
tetrahydrofuran, styrene oxide or epichlorohydrin, either each on its own, 
e.g. in the presence of boron trifluoride, or by addition of these 
epoxides, either as mixtures or successively, to starting components which 
have reactive hydrogen atoms, such as water, alcohols, ammonia or amines. 
Suitable alcohols and amines include ethylene glycol, propylene 
glycol-(1,3) or -(1,2), trimethylolpropane, 
4,4'-dihydroxy-diphenylpropane, aniline, ethanolamine or ethylene diamine. 
Sucrose polyethers may also be used according to the invention, e.g. those 
described in German Auslegeschriften Nos. 1,176,358 and 1,064,938. It is 
in many cases preferred to use polyethers which contain predominantly 
primary hydroxyl groups (up to 90% by weight, based on all the hydroxyl 
groups present in the polyether). Polyethers modified with vinyl polymers, 
e.g. the compounds obtained by polymerization of styrene or acrylonitrile 
in the presence of polyethers (U.S. Pat. Nos. 3,383,351; 3,304,273; 
3,523,093 and 3,110,695 and German Pat. No. 1,152,536) are also suitable, 
as are polybutadienes which contain hydroxyl groups. 
Particularly to be mentioned among the polythioethers are the condensation 
products obtained by reacting thiodiglycol on its own and/or with other 
glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or amino 
alcohols. The products obtained are polythio mixed ethers, polythio ether 
esters or polythio ether ester amides, depending on the cocomponents. 
Suitable polyacetals include, for example, the compounds which can be 
prepared from glycols such as diethylene glycol, triethylene glycol, 
4,4'-dioxethoxydiphenyl dimethylmethane, hexanediol and formaldehyde. 
Suitable polyacetals for the purpose of the invention may also be prepared 
by the polymerization of cyclic acetals. 
The polycarbonates with hydroxyl groups used may be of the kind already 
known, for example those which can be prepared by the reaction of diols 
such as propanediol-(1,3), butanediol-(1,4) and/or hexanediol-(1,6), 
diethylene glycol, triethylene glycol or tetraethylene glycol with 
diarylcarbonates, e.g. with diphenylcarbonate or phosgene. 
Suitable polyester amides and polyamides include, for example, the 
predominantly linear condensates prepared from polyvalent saturated and 
unsaturated carboxylic acids or their anhydrides and polyvalent saturated 
and unsaturated amino alcohols, diamines, polyamines and mixtures thereof. 
Polyhydroxyl compounds already containing urethane or urea groups and 
modified or unmodified natural polyols such as castor oil, carbohydrates 
or starch may also be used. Addition products of alkylene oxides and 
phenol formaldehyde resins or of alkylene oxides and urea formaldehyde 
resins are also suitable for the purpose of the invention. 
Representatives of these compounds which may be used according to the 
invention are known and have been described, for example, in High 
Polymers, Vol. XVI, "Polyurethanes, Chemistry and Technology" by 
Saunders-Frisch, Interscience Publishers, New York, London, Volume I, 
1962, pages 32-42 and pages 44-54 and Volume II, 1964, pages 5-6 and 
198-199 and in Kunstoff-Handbuch, Volume VII, Vieweg-Hochtlen, 
Carl-Hanser-Verlag, Munich, 1966, pages 45 to 71. 
Mixtures of the above mentioned compounds which contain at least two 
isocyanate-reactive hydrogen atoms and have a molecular weight of from 400 
to 10,000 may, of course, also be used, for example mixtures of polyethers 
and polyesters. 
The starting components used according to the invention may also include 
compounds with a molecular weight of from 32 to 400 which have at least 
two isocyanate-reactive hydrogen atoms. These compounds are also 
understood to be compounds containing hydroxyl groups and/or amino groups 
and/or thiol groups and/or carboxyl groups, preferably hydroxyl groups 
and/or amino groups, and they serve as chain lengthening agents or 
cross-linking agents. They generally have from two to eight 
isocyanate-reactive hydrogen atoms, preferably two or three such hydrogen 
atoms. 
The following are examples of such compounds: Ethylene glycol, propylene 
glycol-(1,2) and -(1,3), butylene glycol-(1,4) and -(2,3), 
pentanediol-(1,5), hexanediol-(1,6), octanediol-(1,8), neopentyl glycol, 
1,4-bis-hydroxymethylcyclohexane, 2-methyl-1,3-propanediol, glycerol, 
trimethylol propane, hexanetriol-(1,2,6), trimethylolethane, 
pentaerythritol, quinitol, mannitol and sorbitol, diethylene glycol, 
triethylene glycol, tetraethylene glycol, polyethylene glycols with a 
molecular weight of up to 400, dipropylene glycol, polypropylene glycols 
with a molecular weight of up to 400, dibutylene glycol, polybutylene 
glycols with a molecular weight of up to 400, 4,4'-dihydroxy-diphenyl 
propane, dihydroxymethyl-hydroquinone, ethanolamine, diethanolamine, 
triethanolamine, 3-aminopropanol, ethylene diamine, 1,3-diaminopropane, 
1-mercapto-3-aminopropane, 4-hydroxyphthalic acid, 4-aminophthalic acid, 
succinic acid, adipic acid, hydrazine, N,N-dimethylhydrazine, 
4,4'-diaminodiphenylmethane, tolylenediamine, methylene-bis-chloroaniline, 
methylene-bis-anthranilic acid ester, diaminobenzoic acid esters and the 
isomeric chlorophenylene diamines. 
In this case again, mixtures of various compounds having a molecular weight 
of from 32 to 400 and containing at least two isocyanate-reactive hydrogen 
atoms may be used. 
Polyhydroxyl compounds which contain high molecular weight polyadducts or 
polycondensates in a finely dispersed or dissolved form may also be used 
according to the invention. Such modified polyhydroxyl compounds are 
obtained when polyaddition reactions, e.g. reactions between 
polyisocyanates and amino functional compounds or polycondensation 
reactions, e.g. between formaldehyde and phenols and/or amines are carried 
out in situ in the above mentioned hydroxyl compounds. Processes of this 
kind have been described, for example, in German Auslegeschriften Nos. 
1,168,075 and 1,260,142 and in German Offenlegungsschriften Nos. 
2,324,134; 2,423,984; 2,512,385; 2,513,815; 2,550,796; 2,550,797; 
2,550,833 and 2,550,862. These modified polyhydroxyl compounds may also be 
obtained according to U.S. Pat. No. 3,869,413 or German 
Offenlegungsschrift No. 2,500,860 by mixing a previously prepared aqueous 
polymer dispersion with a polyhydroxyl compound and then removing the 
water from the mixture. When modified polyhydroxyl compounds of this type 
are used as starting components in the polyisocyanate polyaddition 
process, the polyurethane resins obtained in many cases have substantially 
improved mechanical properties. 
According to the invention, water and/or readily volatile organic 
substances may be used as blowing agents. Suitable organic blowing agents 
include, for example, acetone, ethyl acetate and halogen substituted 
alkanes such as methylene chloride, chloroform, ethylidene chloride, 
vinylidene chloride, monofluorotrichloromethane, chlorodifluoromethane, 
and dichlorodifluoromethane as well as butane, hexane, heptane and diethyl 
ether. The effect of a blowing agent can also be obtained by the addition 
of compounds which decompose at temperatures above room temperature to 
release gases such as nitrogen, e.g. azo compounds such as azoisobutyric 
acid nitrile. Further examples of blowing agents and the use of blowing 
agents have been described in Kunststoff-Handbuch, Volume VII, published 
by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich 1966, e.g. on pages 108 
and 109, 453 to 455 and 507 to 510. 
Catalysts are also frequently used according to the invention. The 
catalysts added may be known per se, for example tertiary amines such as 
triethylamine; tributylamine; N-methylmorpholine; N-ethylmorpholine; 
N-cocomorpholine; N,N,N',N'-tetramethylethylenediamine; 
1,4-diazabicyclo-(2,2,2)-octane; 
N-methyl-N'-dimethylaminoethyl-piperazine; N,N-dimethylbenzylamine; 
bis-(N,N-diethylaminoethyl)-adipate; N,N-diethylbenzylamine; 
pentamethyldiethylenetriamine; N,N-dimethylcyclohexylamine; 
N,N,N',N'-tetramethyl-1,3-butanediamine; 
N,N-dimethyl-.beta.-phenylethylamine; 1,2-dimethylimidazole and 
2-methylimidazole. Mannich bases known per se which have been obtained 
from secondary amines such as dimethylamine and aldehydes, preferably 
formaldehyde, or ketones such as acetone, methyl ethyl ketone or 
cyclohexanone and phenols such as phenol, nonylphenol or bis-phenol may 
also be used as catalysts. 
Examples of tertiary amines with isocyanate-reactive hydrogen atoms which 
may be used as catalysts include triethanolamine; triisopropanolamine; 
N-methyl-diethanolamine; N-ethyl-diethanolamine and 
N,N-dimethyl-ethanolamine and their reaction products with alkylene oxides 
such as propylene oxide and/or ethylene oxide. Silaamines with 
carbon-silicon bonds as described e.g. in German Pat. No. 1,229,290, 
corresponding to U.S. Pat. No. 3,620,984, may also be used as catalysts, 
e.g. 2,2,4-trimethyl-2-silamorpholine or 
1,3-diethylamino-methyl-tetramethyl-disiloxane. 
Basic nitrogen compounds such as tetraalkylammonium hydroxides, alkali 
metal hydroxides such as sodium hydroxide, alkali metal phenolates such as 
sodium phenolate and alkali metal alcoholates such as sodium methylate may 
also be used as catalysts. Hexahydrotriazines are also suitable catalysts. 
Organic metal compounds may also be used as catalysts according to the 
invention, in particular organic tin compounds. 
The organic tin compounds used as preferably tin (II) salts of carboxylic 
acids such as tin (II) acetate, tin (II) octoate, tin (II) ethyl hexoate 
and tin (II) laurate and tin (IV) compounds such as dibutyl tin oxide, 
dibutyl tin dichloride, dibutyl tin diacetate, dibutyl tin dilaurate, 
dibutyl tin maleate or dioctyl tin diacetate. All of the above mentioned 
catalysts may, of course, be used as mixtures. 
Further examples of catalysts which may be used according to the invention 
and details concerning the activity of the catalysts are described in 
Kunststoff-Handbuch, Volume VII, published by Vieweg and Hochtlen, 
Carl-Hanser-Vergag, Munich 1966, pages 96 to 102. 
The catalysts are generally used in a quantity of between about 0.001 and 
10% by weight, based on the quantity of formite. 
Surface active additives such as emulsifiers and foam stabilizers may also 
be used according to the invention. Suitable emulsifiers include e.g. the 
sodium salts of ricinoleic sulphonate or salts of fatty acids with amines 
such as oleic acid diethylamine or stearic acid diethanolamine. Alkali 
metal or ammonium salts of sulphonic acids such as dodecylbenzenesulphonic 
acid or dinaphthylmethane disulphonic acid or of fatty acids such as 
ricinoleic acid or of polymeric fatty acids may also be used as surface 
active additives. 
Suitable foam stabilizers are particularly the polyether siloxanes, and 
especially those which are water-soluble. These compounds generally have a 
polydimethyl siloxane group attached to a copolymer of ethylene oxide and 
propylene oxide. Foam stabilizers of this kind have been described, for 
example, in U.S. Pat. Nos. 2,834,748; 2,917,480 and 3,629,308. 
Other additives which may also be used according to the invention include 
reaction retarders, e.g. substances which are acid in reaction such as 
hydrochloric acid or organic acid halides; cell regulators known per se 
such as paraffins, fatty alcohols or dimethyl polysiloxanes; pigments 
dyes; flame retarding agents known per se such as 
tris-chloroethylphosphate, tricresyl phosphate or ammonium phosphate and 
polyphosphate; stabilizers against ageing and weathering; plasticizers; 
fungistatic and bacteriostatic substances; and fillers such as barium 
sulphate; kieselguhr, carbon black or whiting. 
Other examples of surface active additives, foam stabilizers, cell 
regulators, reaction retarders, stabilizers, flame retarding substances, 
plasticizers, dyes, fillers and fungistatic and bacteriostatic substances 
which may be used according to the invention and details concerning the 
use and mode of action of these additives may be found in 
Kunststoff-Handbuch, Volume VII, published by Vieweg and Hochtlen, 
Carl-Hanser-Verlag, Munich 1966, pages 103 to 113. 
According to the invention, the components are reacted together by the 
known one-shot, prepolymer or semiprepolymer process, often using 
mechanical devices such as those described in U.S. Pat. No. 2,764,565. 
Details concerning processing apparatus which may also be used according 
to the invention may be found in Kunststoff-Handbuch, Volume VII, 
published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich, 1966, pages 
121 to 205. 
According to the invention, the reaction for producing foams is often 
carried out inside molds. In this process, the foamable reaction mixture 
is introduced into a mold which may be made of a metal such as aluminum or 
a plastics materials such as an epoxide resin, and it foams up inside the 
mold to produce the shaped product. This process of foaming in molds may 
be carried out to produce a product having a cellular structure on its 
surface or it may be carried out to produce a product having a compact 
skin and cellular core. According to the invention, one or other result 
can be obtained as desired by either introducing just sufficient foamable 
reaction mixture to fill the mold with foam after the reaction or 
introducing a larger quantity of reaction mixture than is necessary to 
fill the mold with foam. The second method is known as "overcharging", a 
procedure which has already been disclosed, e.g. in U.S. Pat. Nos. 
3,178,490 and 3,182,104. 
So-called "external mold release agents" known per se, such as silicone 
oils, are frequently used when foaming is carried out inside molds but the 
process may also be carried out with the aid of so-called "internal mold 
release agents", if desired as mixtures with external mold release agents, 
e.g. as disclosed in German Offenlegungsschriften Nos. 2,121,670 and 
2,307,589. 
Cold setting foams may also be produced according to the invention by the 
processes described in British Pat. No. 1,162,517 and German 
Offenlegungsschrift No. 2,153,086. 
Foams may, of course, also be produced by the process of block foaming or 
by the laminator process known per se. 
The method of reacting only the polyhydroxyl compounds which are obtainable 
according to the invention, without the addition of other isocyanate 
reactive components, with strongly elasticizing polyisocyanates such as 
polyisocyanates which have a biuret structure as described in German 
Auslegeschrift No. 1,543,178, results in hard, light-fast, scratch 
resistant and solvent resistant coatings and lacquers. 
Polyether alcohols with a high functionality can be obtained by basic or 
acid catalyzed propoxylation and/or ethoxylation of the polyols. Among 
these polyether alcohols, those which have high hydroxy numbers may be 
used for the manufacture of rigid or semi-rigid cellular polyurethane 
resins whereas those with low hydroxyl numbers are suitable starting 
materials for highly elastic polyurethane foams. Further details 
concerning the preparation of polyethers may be found in German 
Offenlegungsschrift No. 2,639,083. 
Highly branched polyesters which may be used as additives to alkyd resins 
to improve their hardness can be obtained by reacting the mixtures of 
polyhydric alcohols prepared according to the invention with polybasic 
carboxylic acids of the type mentioned above, such as phthalic acid, 
isophthalic acid, terephthalic acid, tetra- and hexahydrophthalic acid, 
adipic acid or maleic acid by the usual methods of polyester condensation, 
for example as described in Houben Weyl, Methoden der organischen Chemie, 
Volume XIV 12, page 40. The hydroxyl-containing polyesters synthesized 
from the hydroxyl compounds which have been prepared according to the 
invention are, of course, also suitable as starting components for the 
production of polyurethane resins. 
The polyhydric alcohols prepared according to the invention may also easily 
be reacted with long chain, aliphatic monocarboxylic acids such as 
caprylic, capric, lauric, myristic, palmitic, stearic, oleic, linoleic, 
arachidonic or behenic acid or their derivatives, e.g. their methyl or 
ethyl esters, or their anhydrides or mixed anhydrides, to produce 
hydroxyl-containing esters. These esters, like the ethoxylation products 
of the polyols or the carbamic acid esters obtained by reacting the 
polyhydroxyl compounds prepared according to the invention with long chain 
monoisocyanates such as n-octyl, n-decyl, n-dodecyl, myristyl, cetyl or 
stearyl isocyanate (see e.g. K. Lindner, Tenside Volume III, 
Wissenschaftliche Verlagsgesellschaft Stuttgart 1964, page 2336), are 
non-ionogenic, surface active compounds which are valuable emulsifiers, 
wetting agents and plasticizers. The compounds according to the invention 
may also be used as moisturizers in cosmetics and synthetic resins. 
They may also be used, for example, as anti-freezes or as additives in 
formulations for plant protection.

The following examples serve to explain the process according to the 
invention. Quantities given represent parts by weight of percentages by 
weight unless otherwise indicated. 
Examples 3 and 4 show that the quantity of catalyst required is very small. 
EXAMPLES 
Example 1 
(Comparison Example) 
This example shows that in processes known in the art, using much longer 
times and larger quantities of catalyst, a higher proportion of C.sub.6 
-C.sub.8 components is obtained than in the process according to the 
invention. 
250 ml of a formose solution according to Example 1 of German 
Offenlegungsschrift No. 2,721,186 are hydrogenated with 80 g of Raney 
nickel in a 0.7 liter autoclave at a hydrogen pressure of 150 bar for 4 
hours at 30.degree. C., then for 1 hour at 60.degree. C. and finally for 1 
hour at 100.degree. C. 
A slightly yellowish solution of polyhydroxyl compounds containing 0.018% 
of reducing groups and having the following molecular distribution is 
obtained: 
______________________________________ 
Compounds containing 2 C atoms 
0.8 
Compounds containing 3 C atoms 
2.2 
Compounds containing 4 C atoms 
5.6 
Compounds containing 5 C atoms 
30.4 
Compounds containing 6 C atoms 
40.0 
Compounds containing 7 or more C atoms 
21.0 
______________________________________ 
Example 2 
(Comparison Example) 
This example shows that neither adjustment of the pH to an alkaline value 
nor increase in temperature alone is capable of producing the low 
molecular weight distribution of components obtained in the following 
examples. 
250 ml of the formose solution from Example 1 are adjusted to pH=10 and 
hydrogenated with 80 g of Raney nickel in a 0.7 liter autoclave at 150 bar 
hydrogen pressure for 30 minutes. The temperature is raised from 
30.degree. C. to 100.degree. C. during this time. The solution is 
hydrogenated for 1 hour at 100.degree. C. and then for 1 more hour at 
140.degree. C. A colorless solution in which no more reducing constituents 
can be detected and which has the following molecular distribution is 
obtained: 
______________________________________ 
Compounds containing 2 C atoms 
3.2 
Compounds containing 3 C atoms 
8.0 
Compounds containing 4 C atoms 
12.6 
Compounds containing 5 C atoms 
33.6 
Compounds containing 6 C atoms 
27.0 
Compounds containing 7 or more C atoms 
16.6 
______________________________________ 
General Method of Hydrogenation 
(Examples 3 and 4) 
100 parts of catalyst (C) in 300 parts of water are introduced into a 3 
liter refined steel autoclave and heated to the hydrogenation temperature 
(T). The volume above the water is then filled with hydrogen gas at the 
operating pressure (P). 500 parts of a 50% formose solution prepared 
according to Example 1 of German Offenlegungsschrift No. 2,721,186, 
containing 11.1% of reducible groups (determined as carbonyl groups) are 
adjusted to the required pH and then pumped into the autoclave within a 
predetermined pumping time (PT). Hydrogenation is then continued for a 
fixed period of time (HT). 500 parts of solution are then discharged 
through an upright pipe containing a frit which holds back the catalyst. 
The process is repeated with the next batch of formose solution containing 
500 parts. Hydrogenation is continued until the activity of the catalyst 
falls or until the required number of cycles has been performed or the 
required quantity of product has been obtained. No loss of catalyst was 
found to occur even after many cycles of hydrogenation. The hydrogenated 
solutions are collected and freed from most of the water in them by 
evaporation under vacuum. Colorless to pale yellowish formites which can 
be worked up without further purification are obtained in all cases. If 
desired, the solutions may be completely desalted over ion exchange 
resins. The distribution of components indicated was calculated from gas 
chromatographic analyses. 
Example 3 
This example shows that in the process according to the invention, 
hydrogenation may be carried out with very little consumption of catalyst. 
______________________________________ 
T = 100.degree. C. 
pH = 10.0 P = 150 bar C = Raney nickel/ 
PT = 25 min. 
HT = 25 min. iron (85%/15%) 
Batch Number % &gt; C = 0 
______________________________________ 
1 0.016 
2 0.016 
3 0.016 
4 0.016 
5 0.016 
6 0.016 
7 0.016 
8 0.016 
9 0.016 
10 0.016 
20 0.031 
30 0.031 
40 0.031 
50 0.031 
100 0.040 
150 0.023 
200 0.029 
250 0.020 
300 0.028 
350 0.014 
400 0.032 
______________________________________ 
A colorless solution by mixing the solutions of all batches having the 
following molecular distribution is obtained: 
______________________________________ 
Compounds containing 
2 C atoms 3.9% by weight 
3 C atoms 20.7% by weight 
4 C atoms 24.1% by weight 
5 C atoms 22.4% by weight 
6 C atoms 22.0% by weight 
7 or more 6.8% by weight 
______________________________________ 
Example 4 
This example shows that hydrogenation can be effected very rapidly with 
little consumption of catalyst by the process according to the invention. 
______________________________________ 
T = 140.degree. C. 
pH = 10.5 P = 150 bar C = Raney nickel/ 
PT = 6 min HT = 6 min iron (85%/15%) 
Batch number % &gt; C = 0 
______________________________________ 
1 0.005 
2 0.005 
3 0.006 
4 0.008 
5 0.006 
6 0.005 
7 0.006 
8 0.006 
9 0.012 
10 0.012 
20 0.014 
30 0.014 
40 0.025 
50 0.031 
100 0.034 
150 0.042 
200 0.027 
260 0.023 
______________________________________ 
A colorless solution by mixing the solutions of all batches having the 
following molecular distribution is obtained: 
______________________________________ 
Compounds containing 
2 C atoms 6.8% by weight 
3 C atoms 19.3% by weight 
4 C atoms 22.3% by weight 
5 C atoms 19.0% by weight 
6 C atoms 20.0% by weight 
7 or more 12.6% by weight 
C atoms 
______________________________________ 
Example 5 
Preparation of a polyurethane foam. 
25 parts of a polypropylene oxide (hydroxyl number 74) which has been 
started on ethylenediamine, 
22 parts of the formite from Example 3, 
10 parts of trichloroethyl phosphate, 
15 parts of monofluorotrichloromethane, 
0.5 parts of dimethylbenzylamine, 
0.5 parts of a commercial silicone stabilizer (L-5420 of UCC) and 
75 parts of a commercial phosgenation product of aniline/formaldehyde 
condensates (isocyanate content: 29%) 
are mixed vigorously and the resulting mixture is left to foam up in an 
open mold. A rigid, fine celled foam which has high tear resistance and 
dimensional stability is obtained.