DE1295832B - Process for the production of a thermoplastic polyurethane - Google Patents

Description

1 2

The invention relates to the preparation of a thermally free diisocyanate to react. The plastic polyurethane, especially the production amount of isocyanate groups and free diisocyanate of a non-discoloring thermoplastic polyurethane, can be done by analyzing a small part of the reaction ethane. Product can be determined. The invention relates to a process for the preparation of between 0.9 and 1.1 moles of diol incorporated per mole of iso of a thermoplastic polyurethane by means of recyanate groups, including free diisocyanate.
Setting of a prepolymer from polymeric diols The reaction product is analyzed for the determination of the and aliphatic diisocyanates with a mono- required amount of the diol to be added for chain extension in the presence of a catalyst, the amount of the diol used is characterized in that the molar ratio is io but can also be based on a molar ratio of aliphatic diisocyanate to the monomeric ratio of the aliphatic diisocyanate used for the preparation of the diol reaction product in the range from 1: 0.9 («- I) to 1: 1.1 (h-l) / w Diol im is where u is greater than 1 and expresses the molar ratio range from 1: 0.9 {u-I) Iu to 1: 1.1 (µ ~ 1) / µ in of diisocyanate to polymeric diol. where u is the molar ratio of di-isocyanate to polymeric diol and, as before a thermoplastic polyurethane consists in this, is greater than 1, preferably that under anhydrous or practically anhydrous 2 to 3.

Conditions of a reaction product with two final catalysts are a) triethy-

permanent or practically terminal groups in lenediamine, its homologues and analogs, e.g. B. the Molecule, each of which is an aliphatic radical with 20 corresponding compound in which the nitrogen passes through has an isocyanate substituent, is replaced with a diol phosphorus, and b) esters, alkyl esters and salts and a catalyst to accelerate the group IV, V and VI metals of the perio chain extension of the reaction product mixed in the system, whereby Group IV metals are used, be preferred, especially those in the lower

The reaction product with the two terminal groups that contains tin. Examples of these catalysis or practically terminal isocyanate groups in the gates are the dialkyltin diesters of fatty acids, eg. B. Molecule is made by reacting a diol with a dibutyltin dilaurate, and divalent tin soaps, e.g. B. obtained aliphatic diisocyanate. Preferably tin (II) octoate and tin (II) oleate.
the diol consists of a practically linear polymer. The reaction product of the diol can in one

Diol (molecular weight over 500) and can be dissolved from a poly 30 solvent, e.g. B. in aliphatic ether, polyester or polyester amide. Poly ketones, such as acetone and methyl isopropenyl ketone, esters with virtually unbranched molecular chains and aromatic compounds, e.g. B. chlorobenzene. That are preferred, and if a polyurethane is desired reaction product can also be prepared in solution which is resistant to water, by putting the polymeric diol in a solution a based on neopentyl glycol polyester 35 medium dissolved and then the polymeric diol with the preferred. If the polyurethane is to be converted into aliphatic diisocyanate with respect to water. Always must be extremely resistant, the diol should be practically anhydrous and the solvent used Polyether with polymethylene oxide units not reactive with the reaction product, diol

and aliphatic diisocyanate.

- (CH ₂ ) O - 40 When referring to »aliphatic compounds«

is taken are compounds with alicyclic

where η is an integer greater than 2. Structure also includes, and with the expressions examples of such polyethers are the polytetra- "isocyanate", "ether" and "diol" become the entspremethylene glycol ethers (molecular weight 500 or above). corresponding sulfur analogues, ie isothiocyanate thio-The polymeric diol is intended to mean three or more carbon ethers and thiol compounds,
atoms in the repeating monomeric unit

have, and it is a non-aromatic diol BE obtained thermoplastic polyurethane, which by preferred. Light is not discolored. The one with diol, catalyst

Typical aliphatic diisocyanates that are used and optionally mixed with solvent can, are dicyclohexylmethane diisocyanate 50 action product can be cast into foils, and hexamethylene diisocyanate. In most cases, the reaction between the real 1 mole of diisocyanate per mole of polymeric diol to form the reaction product and the diol is increased by heating position of the reaction product used, e.g. not caused above 125 ° C.

between 2 and 3 moles of diisocyanate per mole of polymer. The invention is illustrated by the following examples

Diol. 55 explains where all parts are by weight

That are drawn to chain extension of the reaction product.

Diol used has two terminal or practically Example 1

terminal - OH groups and preferably consists

from a di-primary aliphatic alcohol (mole 200 parts of a polytetramethylene glycol of one

weight less than 500), but diols with a molecular weight of about 3000 can be used by heating under a higher molecular weight, as can vacuum, apart from a very slow one-di-aliphatic alcohol. Typical examples of circuit-pure nitrogen, for 2 hours at 110 to play for diols sind_die short chain aliphatic 120 ⁰ C with stirring dehydrated. The temperature of diols such as butanediol, ethylene glycol and trimethylene was lowered to 100 ° C. and then glycol was constant. In order to hold a thermoplastic polyurethane and maintain it with stirring and nitrogen blowing, the reaction product has to be handled, while 52.5 parts of diol mixed with dicyclohexylmethane diol are sufficient to be added with velvet cyanate. The mixture was heated with borrowed isocyanate groups and possibly 100 ^° C. for 2 hours and then cooled.

Claims (3)

3 4 The water-clear syrupy liquid obtained had agitation and nitrogen sparge continued a viscosity of 45,000 cps at 25 ⁰ C. was, while 45 parts Dicyclohexylmethandiiso-To 100 parts of the liquid polymers were cyanate were added, followed by stirring and Er-3.0 Part 1,4-butanediol and 0.1 part dibutyltin heating were continued for 2 hours. The product laurate was added as a 3% solution in acetone. 5 was cooled to 5O ⁰ C and 6.4 parts of 1,4-butanediol The mixture was poured onto glass plates, where, and 0.1 part of dibutyltin dilaurate and they were formed thin layers, which then at 100 ⁰ C1 200 parts of dry STUN Chlorobenzene added. The temde were heated. After cooling were the temperature was increased and stripped for 2 hours at 100 ⁰ C layers of the plates, whereby to-held, with stirring and nitrogen was bubbled sammenhaftende films exhibited. Parts were heated io. A vacuum was then applied and that and became ^{plastic at about 150 0} C; Removed chlorobenzene from the polymer on cooling. This solidified this material and became plastic again while the polymer held was a tough rubbery heating. thermoplastic polyurethane, which ^{tests carried out at 150 °} C. with parts of the film yielded soft and became liquid ^{at 200 ° C.} It is easy to result in the following: 15 organic solvents, such as methylene chloride and Tensile strength, kg / mm «3.38 ^acetone > ^and methyl ethyl ketone soluble. Module at 300% elongation, kg / mm ² 0.36 Claims: Elongation at break, ⁰ / «750. _ΛΛ . . _TT ". , Condition after immersion at ^ao , ^L Υ ** ³ * ¹ ™, ™ ^Her ' ^teI1 " ^ng _TT ^{emeS therm} °" 5O ⁰ C for 24 hours of plastic polyurethane by implementing a Y _n . Prepolymers from polymeric diols and ahpha- Petroleum naphtha unchanged! ^een! "isocyanates with a monomeric diol Carbon tetrachloride .... swollen ^m the presence of a catalyst characterized 10 ⁰ I HCl sticky ^{a5 denotes} that the molar ratio 100 / Ü H ₂ SO ₄ ''.'.'.'.'.'.'.'.'.'.'.'.'. very little stickiness of ^the aliphatic diisocyanate to the monomeric one 10 "HO ₂ very little sticky diol in the range from 1: 0.9 (u-1) /" to 1: 1.1 1 ° / "NaOCl not very sticky ^ Ι ^ Ψα ^ ° ^Πη " iP ^{ßer than λ and that} 10 ° / ₀ NaOH not very sticky ™? ^l f ^rs ratio of diisocyanate to polymeric '"30 diol prints out. . 2. The method according to claim 1, characterized Example λ shows that the formation of the reaction pro- 100 parts of a neopentyl glycol sebacic acid poly- duktes used from a polymer with Esters (average molecular weight about 1750) were composed by a molecular weight above 500. Heating to 110 to 12O ⁰ C with stirring under 35 3. The method according to claim 1 and 2, characterized reduced pressure in pure nitrogen while characterized that the with the reaction pro- Dehydrated for 2 hours. The temperature was reduced and the catalyst mixed diol to form a low and kept at 100 ⁰ C, with the kular weight of less than 500 possesses.