DE1618845B - Process for the production of storage-stable, liquid toluylene diisocyanate raw mixtures - Google Patents

Description

3 4

definitely. To make a product that is a they are not as excessively low viscosity as ge

Amine equivalent within the range mentioned purified toluylene diisocyanate and can at

a mixture of tolylene diisocyanate and mechanical foaming can occur even under extreme conditions

tarry substances are modified, which are handled up to 15 Ge conditions. they have one

contains tarry substances by weight. Toluylene diiso- S low freezing point below 0 ° C, so it

cyanates, which are produced by phosgenation of toluene di- in contrast to purified toluene diis-

amines usually contain about cyanates which makes them easy to use

5 percent by weight of tarry substances. Determining the winter to transport and use.

The content of tarry substances can therefore be found in the _{3 The}

most traps by removing part of the toIu- io _{haUenen teeri matter} . _faen ^^ _{dmch Oesm} _

perform ylendnsocyanates. lation and separation are lost, but the reaction

Amm equivalent is the number of grams of a toluylenediamine phosgenation ion product

Isocyanates to be understood, which from 1 gram-mole of di- _{can in this stage into the end product} !

n-butylamm with the formation of the corresponding urine _{, which leads to considerable economic benefits}

Substance compound are consumed. The determination 15 _te jj _e i. _at
takes place by adding an excess of 2 N-Di-

n-butylamine to a known amount of the isocyanate- The examples illustrate the invention. Parts mean

mixture gives and the excess of butylamine parts by weight,

back-titrated. For example, the amine equi-example is 1
valent of a toluene diisocyanate with a mol- 20

Weight of 174, the two isocyanate residues in the It is a solution of toluene diamines (one

Molecule contains 174/2, ie 87. Mixture of about 80 ° / _? 2,4-tolylenediamine and about

The 20% 2,6-tolylenediamine) and dichlorobenzene used in accordance with the invention as starting material in a single reaction product are phosgenated by weight ratio of 12: 130 and a solution of tolylenediamines according to the usual. The method produces phosgene and dichlorobenzene in one weight behavior. In most cases the phosgenation ratio is 1: 2. The toluenediamines and tolylenediamines in the presence of a phosgene solution are carried out in portions of 142 parts by means of such as dichlorobenzene. In these or 90 parts per hour in the first reactor, in which case the solvent is expediently introduced before it is ^{kept at 30 °} C., and the reaction modification is separated off again from the product. 30 is carried out. The reaction product will then

Organotin compounds are preferably converted in a second reactor, which uses at about 70 ⁰ C, the following compounds: stannous octoate, is maintained. Phosgene tin oleate, tin acetate, dimethyl tin diacetate, dibutyl- is introduced into the second reactor until the reaction liquid has become slightly liquid tin diacetate, dibutyl tin dilaurate, dibutyl tin distearate. The reaction liquid is turned into a dilauryl tin diacetate. The organotin compound in the third reactor, which is kept at 160 ^° C., is passed in an amount of 0.1 to 2 percent by weight, and the reaction is brought to an end. In the reaction is preferably 0.5 to 1.0 weight percent, based on product dry nitrogen is introduced at 130 to 160 ⁰ C, the reaction product of Toluylendiaminphosgenie _r used by the unreacted phosgene and the tion. The working temperature affects the hydrogen chloride removal. The reaction rate and the properties of the dichlorobenzene are then removed by vacuum distillation and the product obtained. An effect is observed even at a mixture of toluene diisocyanate and 5.5% Teeri-150 ⁰ C. The preferred temperature is when substances are obtained as a by-product. The mixture, however, in the range 200-230 ⁰ C, at higher had an amine equivalent of 90.7 and a viscous temperatures, the effect of Qrganozinnverbin- sity of about 10 cP at 25 ° C. The viscosity of the Gedung Although increased , but the toluene diisocyanate mixture was essentially the same as that of then strongly degraded. For this reason, tolylene diisocyanate is alone. ■ .. · ,; Temperature of over 250 ⁰ C inexpedient. The he-. To 1300 parts of this mixture, 13 parts can be heated, carried out in one or in two stages, tin octoate is added as a catalyst. The obtained e.g. B. initially at 150 to 200 ⁰ C, and then mixture is dry under nitrogen RühTenin 200 heats the organotin compound or the 5 ° atmosphere at 200 ⁰ C to 250 ⁰ C.. After heating the Er reaction product of the toluylenediamine phosgenation for one hour, the reaction liquid is cooled; it can also be introduced separately into the heating zone. receives 1288 parts of a completely homogeneous toluene di-

The crude toluylene diisocyanate mixture obtained according to the invention. The analysis showed that the

Crude cyanate mixtures have the following advantages: Product has an amine equivalent of 110 and a viscous

_H _. _,,,,. . _{,, A} 55 sity of 13OcP at 25 ° C and 0.09 weight percent

1. The products contained a sufficient amount of amine, _{saponifiable chlorine} . _{In the} distillation equivalent and a low isocyanate residue- ^^ _{70 5} percent by weight of distilled toluene content per unit weight compared to _{diisocyanate and} 29.5 percent by weight of tarry substances remitted toluene dusocyanates There is therefore _{ac residue obtained} .

no excessive _{6o Bd} in the reaction with polyols, _{the obtained} Joluylendiisocyanatroh _SQ-heat development It is therefore possible to ^^ _{falleQ bd 3-month} standing no Undem shot process _{soluble substances from} Polyurethanhartschaum-.
to obtain fabrics with excellent properties. Example 2

2. The products usually have a viscosity of 65,100 parts of the mixture obtained in Example 1 from 30 to 300 cP at 25 ° C and are completely homo- made from toluene diisocyanate and tarry substances Genetic and stable liquids from which 6.5 parts of dibutyltin dilaurate are added. The none Separate insoluble substances. In addition, it is mixed with stirring for 15 hours in the dryer

5 6

Nitrogen atmosphere heated to 23O ⁰ C. Then, the crude toluylene diisocyanate mixture is kept falling after the reaction liquid has cooled; no insoluble substances are obtained after standing for 3 months. 1283 parts of a completely homogeneous toluene diiso-. .
raw cyanate mixture. The analysis showed that the Pro Example 5
Dukt had an amine equivalent of 105.8 and a viscosity of 5,650 parts of the mixture obtained in Example 1 sity of 35 cP at 25 ° C and 0.09 percent by weight of toluene diisocyanate and tarry substances contained zent saponifiable chlorine. During the distillation with 13 parts of tin octoaf added and 7 hours in 80 weight percent of distilled toluene diiso- dry nitrogen atmosphere were ^{heated to 160 0} C, cyanate and 20 weight percent of tarry substances as Then a further 650 parts of the same mixture residue are obtained. In the case of the toluene-io thus obtained from toluene-diisocyanate and tarry substances, crude diisocyanate mixture precipitates after standing for 3 months, and the mixture is kept at 220 ° C. for 2 hours, and no insoluble substances are released. hitzrrEs are 1245 parts of a completely homogeneous

^. -I ^ ". '* ..: T®iuyiendns'ocyanatrohgemisches obtained. The ana-

Ji e ι s ρ ι el J. ..-_ ■ -.: Ij _y ^ _e gjg ^ <j _a ß the product is an amine equivalent of

From 2600 parts of the Ge 15 114 obtained in Example 1 and had a viscosity of 21OcP at 25 ° C and Mixture of toluene diisocyanate and tarry substances contained 0.09 percent by weight saponifiable chlorine. at 1300 parts of tolylene diisocyanate are distilled off. of the distillation, 68.5 percent by weight were distilled is a partially concentrated tolylene diisocyanate and 31.5 percent by weight obtained cyanate liquid containing about 11 weight of tarry substances as residue. With that so great contains tarry substances. 1300 parts of this crude toluene diisocyanate mixture containing toluene ao fall afterwards If 13 parts of tin octoate are left to stand for 3 months, diisocyanate liquid will not form any insoluble substances. added and with stirring for 4 hours in a dry place. . .

Heated to 230 ° C in a nitrogen atmosphere. Then the comparative example

Reaction liquid cooled. This gives a completely The mixture of toluene obtained in Example 1

homogeneous toluylene diisocyanate mixture in 98% strength ² 5 diisocyanate and tarry substances was according to the yield. The analysis showed that the product had a usual concentration method at 120 ° C / 10 Torr amine equivalent of 113.5 and a viscosity of distilled and so a certain amount Toluylendiiso-98 cP at 25 ⁰ C and 0.18 weight percent of comparable cyanate removed. The distillation contained a soluble chlorine.In the distillation, centered crude tolylene diisocyanate was obtained, which contained 69.5 percent by weight of distilled tolylene diisocyanate, 30.5 percent by weight of tarry substances and 30.5 percent by weight of tarry substances as a residue of concentrated tolylene diisocyanate of Example 3. In the case of the tolylene diisocyanate obtained in this way,. The analysis showed that the product was a crude mixture precipitated after 3 months of standing amine equivalent of 118.2 and a viscosity of no insoluble substances. Had more than 500 cP at 25 ^{° C.} That was unfavorable

_. . . . 35 the product immediately after cooling off insoluble

Example 4 began to fall. After a week the whole thing was raw

1300 parts of the mixture obtained in Example 1, liquid essentially in a gel-like addition of toluene diisocyanate and tarry substances, are transferred. This gel-like mass was admixed with 10.5 parts of tin acetate and triturated with stirring. An insoluble precipitate, for 8 hours in a dry nitrogen atmosphere was obtained at 40 heated Gewichtspro 210 ⁰ C during washing with cold benzene to 6.9. Then, the reaction liquid was slightly insoluble in benzene.

chilled. There are 1270 parts of a completely homogeneous next, the above-mentioned simple concentration

Raw toluene diisocyanate mixture obtained. The application process is interrupted as soon as the salary has reached lysis showed that the product was an amine equivalent of tarry materials 20 percent by weight. Man he-107 and had a viscosity of 95 cP at 25 ° C. and so held a concentrated product analogous to Example 2. Contained 0.09 percent by weight saponifiable chlorine. This product also fell insoluble in large quantities 72 percent by weight was borrowed from the distillation; after a week the in stilh'ertes toluylene diisocyanate and 28 percent by weight of benzene-insoluble compounds 4.2 percent by weight proteinaceous Substances obtained as a residue. With that so very often.

Claims (3)

1 ■ 2 toluene isocyanate is obtained if a mixture of claims: · the toluene isocyanate and the tarry substances are subjected to vacuum distillation, the toluene- 1. Process for the production of storage diisocyanate distilled off and the content of tarry 'stable, liquid toluylene diisocyanate raw mixtures 5 substances increased. On the other hand, it was observed that see from the reaction product of the toluene-toluene diisocyanate when standing to precipitate un- diamine phosgenation, which means that substances tend to be soluble. These are particularly unstable draws that the reaction product in crude toluene diisocyanate, which the tarry substances in Contain the presence of 0.1 to 2 percent by weight of a concentrated form. Usually fall at Organotin compound of the general formula io these products in a short time several percent un- ■ Γ: · '. soluble substances. The insoluble substances are true- Sn (OGOR) ₂ or R ' ₂ Sn (OCOR) ₂ ; ■ apparent. Dimers and / or polymers formed from the isocyanates. Your education increases with the in .der R and -R 'aliphatic hydrocarbon concentration of tarry substances. These insoluble mean residues, heated to 150 to 250 ° C. 15 substances are, however, extremely sustainable when foamed 2. The method according to claim 1, characterized in part, in particular during mechanical foaming, draws that an organotin compound is tin- From the German Auslegeschrift 1195 298 it is octoate tin oleate, tin acetate, dimethyl tin - known, liquid, undistilled toluene diisocyanate, acetate, dibutyltin diacetate, dibutyltin dilaurate, which have an IR spectrum at 7.37 μ, at higher Dibutyltin distearate and dilauryltin diacetate react at 20 temperatures with phosgene until the product turns, products are free from the maximum at 7.37 μ. Which he- 3. The method according to claim 1, characterized products are somewhat more stable than the distinction that the organotin compound is used in the raw material, but still for the "one-shot" process Amounts of 0.5 to 1 percent by weight are used. not completely satisfactory. 25 The object of the invention is to produce storage-stable, liquid toluylene diisocyanate raw mixtures, which do not precipitate any insoluble "substances and to "Manufacture of rigid polyurethane foams by the" one-shot "process are suitable. This Auf-30 would be solved by the invention. Polyurethane foams are known to be the subject of the invention is thus a process Reaction of compounds with at least two for the production of storage-stable, liquid toluene-active hydrogen atoms, ... mostly polyester or ylene diisocyanate raw mixtures from the reaction polyether glycol with diisocyanates in the presence of toluene diaminophosgenation, which produces propellants, catalysts and, for example, wetting agents - 35 is characterized in that the reaction product is placed in. In particular, 0.1 to 2 percent by weight of a rigid orgaurethane foams from toluene diisocyanates is used for the production of poly-tin compound of the general formula
and Z. B. a polyether glycol the so-called »Pre- polymer «method used in which the toluene-Sn (OCOR) ₂ or R ' ₂ Sn (OCOR) ₂ , diisocyanate with part of the polyether glycol to 40 a prepolymer is implemented. Then the rest of the polyether glycol, which is aliphatic hydrocarbon radicals in the R and R ', is added and the reaction is heated to 150 to 250 ° C,
completed. The Toluyiendiiso- Compared to this prepolymer process, raw cyanate mixtures are completely stable and do not form any undas so-called "bne-shot" processes, in which the 45 soluble precipitates and, are suitable for the production of foaming takes place in one stage, simpler and treatment of rigid polyurethane foams according to the quemer. However, the manufacture of polyurethane has a one-step process. rigid foams according to the »one-shoti process. In the process according to the invention, a at the -cleaned. Toluylene diisocyanate uses part of the tohrylene diisocyanate in a non-volatile are, to this day, practically unsuccessful .'50 converted to tarry components; effective - remains It is known to be suitable diisocyanates for approximately half of the isocyanate component. It is therefore possible to use crude toluylene diisocyanates in one-step process to use crude toluene diisocyanate mixtures. The use of crude toluene diisocyanates to obtain high yields that is not only different from the usual cyanates. with regard to the manufacturing. _T completely differentiate between crude toluene diisocyanates and vöifienV because here the one-step ratio syi-Derärfige ’toluene diisocyanate mixtures cannot be used, but because they are more insoluble’ Shafts of the rigid foams obtained are used as starting material for polyurethanes, preferably have an amine. In the production of toluylene diisocyanates, the equivalent of about 105 to 120 and a content of toluylene dusocyanate from the reaction of tolylene diamines with phosgene 60 of about 65 to 85 percent by weight result in tarry by-products. These tarry fabrics zenf. The toluene diisocyanate content can easily be removed and cannot be removed by distillation, so that this can be expected if the residue obtained during the distillation of the toluene is obtained during the distillation. In addition, they contain small amounts of isocyanate ylenediisocyanate. In addition, the amine residue can be used as an active ingredient. The amount of tarry substances obtained as secondary equivalents, depending on requirements, is usually about 5 percent by weight without the toluene dusocyanate content. change when you look at the tarry content in the It is also known that the abovementioned reaction product of tolylenediamine phosgenation can be used