DE1114029B - Process for the production of molded articles from polyurethane elastomers - Google Patents

Description

The invention relates to improvements in the manufacture of synthetic rubber-like fabrics from Polyesters, polyester amides or polyethers and polyisocyanates.

It is known to produce such elastomers by reacting organic polyisocyanates with polyesters, To produce polyester amides or polyethers. It is also known to use mixtures of polyesters or polyester amides apply to manufacture elastomeric products that have particularly desired features or have physical properties.

The German Auslegeschrift 1 092 647 discloses a process for the production of molded articles from polyurethane elastomers by reacting mixtures of at least two polyester or polyester amide resins, of which at least one polyester or polyester amide is crystalline and high-melting, with the addition of excess polyisocyanate at temperatures not below 3O suggested ⁰ C of the melting point of the highest melting resin component and curing the composition at a least 2O ⁰ C below the mixing temperature lying temperature in such a way that such used as the highest-melting polyester or Polyesteramidkomponente having a melting point of at least 182 ⁰ C. . In this way, the crosslinking is carried out at a temperature at which the mixture acquires a degree of hardness due to the high-melting component; this crosslinking, which progresses relatively quickly, stabilizes the shape of the uncured product so that it is removed from the mold with little risk of deformation and now z. B. can be cured in an oven.

In the German Auslegeschrift 1 097 130, a process for the production of moldings from polyurethane elastomers by treating a mixture of at least two polyester or polyester amide resins, of which at least one component does not ^{melt below 182 0} C, with excess polyisocyanate at a temperature not more than 30 proposed ° C below the melting point of the highest melting resin component of the mixture and curing the reaction product at a minimum of 20 ⁰ C lower than the mixing temperature lying temperature in accordance with Patent 1,092,647 in such a way that the reaction product formed from the mixture of the polymer and the polyisocyanates with 40 ⁰ C quenched, then optionally deformed at an elevated temperature and hardened in a manner known per se.

It has now been found that this improvement process for the production given in German Auslegeschrift 1,097,130
of molded articles made of polyurethane elastomers

Applicant:

Imperial Chemical Industries Limited,
London

Representative: Dr.-Ing. H. Fincke, Berlin-Lichterfelde, Drakestr. 51, Dipl.-Ing. H. Bohr and Dipl.-Ing.

S. Staeger, Munich 5, patent attorneys

Gerald Patrick Crowley, Manchester,

Lancashire (UK),

has been named as the inventor

also on the production of molded articles from polyurethane elastomers from organic polyisocyanates and other polyesters, polyester amides and polyethers is applicable.

According to the invention, an improved process for the production of molded articles from polyurethane elastomers by reacting one or more polyesters, polyesteramides or polyethers with an excess of a polyisocyanate while quenching the reaction mass is proposed in such a way that the liquid reaction mixture, which optionally contains at least two Contains isocyanate-reactive groups containing crosslinking agent, with the exception of one based on one of at least two polyester or polyester amide resins, of which at least one component does not ^{melt below 182 0} C, by adding excess polyisocyanate at a temperature not more than 30 ⁰ C below the melting point of the highest melting resin component obtained reaction mass, cooled to below 80 ° C and then shaped and cured in a conventional manner.

The quenching can be preferably carried out in detail in the German Auslegesehrift 1,097,130 manner indicated by lowering the temperature of the reaction mixture to between 20 and 35 ⁰ C,. When emptied, the material is usually sufficiently coherent that it can be removed in about 5 to 20 minutes at temperatures between 20 and 20 minutes

109 689/231

3 4

and 25 ° C to process. The invention is illustrated by the following examples, processing stage, including the production of, in which the parts and percentages are based on the coated fabric, and the advantages are based on weight,
the method according to the invention, in more detail in the German Auslegeschrift 1097 130 5 Example 1
described.

120 parts of polyethylene glycol adipate (molecular weight

wetting agents are, for example, glycols, more weight 1850, acid number 2.5) are heated and

Valuable alcohols, which more than two hydroxyl stirring at 170 to 180 ⁰ C under reduced pressure

groups per molecule, or diamines. io (11.5 mm Hg) dehydrated. After 10 minutes with this one

As examples of the polyesters, polyester amides and temperature, the vacuum is then lifted

Polyethers are the substances that are first 0.15 parts of adipic acid and then in the loading list

Letters of Patent 1092,647 are given, 18.0 parts of 1,5-naphthylene diisocyanate were added. That

in particular polyethylene glycol adipate, stirring is 5 minutes at ordinary pressure,

Polyethylene glycol glutarate, polyethylene glycol azelate, 15 then a further 5 minutes under reduced pressure

Polydiethyleneglycol adipate, Polydiethyleneglykolgluta- (11.5 mm Hg) continued with the temperature at

rat and polypentamethylene glycol glutarate and poly- 180 ° C is kept. The mixture is then in

mixed ester, which was pretreated from the polyethylene glycol adipate with a mold release agent (»ge

by replacing part of the adipic acid and / or smeared «) metal wells, in which they are poured on

cool the ethylene glycol component with other acids 20 room temperature. The cooled material

or derived from glycols. stays there for 1 hour, the plate is then removed from the

Troughs and 1 mm thick films are taken as examples of organic diisocyanates

Mentioned: Diphenylmethane-4,4'-diisocyanate, naphthy between "lubricated" plates made of stainless steel

len-l, 5-diisocyanate, p-phenylene diisocyanate, naph- by heating to 110 ° C for 1 ¹ ^ hours

ethylene-1,4-diisocyanate, 4,4-'Diphenylen-diisocyanat, 25 pressed ^{a pressure of 1.05 kg / mm 2.} The so

3,3'-Dimethyl-4,4'-diphenylene diisocyanate, diphenyl-recovered film is removed from the press and

ethane-4,4'-diisocyanate, toluene-diisocyanate, 3,3'-di- hardened for a further 48 hours at 110 ° C in an oven, methyl - diphenylmethane - 4,4 '- diisocyanate, dibenz-

furan-2,6-diisocyanate, 3-methyl-4,4'-diisocyanatodi- Example 2
phenylmethane or mixtures thereof. 3 °

The hardening of the mixture can be carried out in a known manner by 100 parts of polyethylene glycol adipate (molecular weight

be carried out, e.g. B. in an oven at the weight 2010, acid number 2.3) are heated up

desired temperature is maintained. Appropriately 170 to 180 ⁰ C with stirring and a pressure of

the curing process can dewater at a temperature of 10 mm Hg. After 10 minutes with this one

between 100 and 150 ° C. 35 temperature, the vacuum is lifted and only

Other additives can add to the NCO groups - 0.15 parts of adipic acid, then 15 parts of 1,5-naphthylene-

pointing polyester or polyester amide urethane diisocyanate added. Stirring is 5 minutes

be incorporated, z. B. Curing agent and curing under ordinary pressure, then another 5 minutes

catalysts, such as tertiary amines, fillers, such as carbon black, continued under a pressure of 10 mm Hg. then

Iron oxide, glue, barite, ground chalk, 1.05 parts 1,4-butylene glycol are added. the

Lithopone, other organic and inorganic mixture is applied for 1 minute at ordinary pressure

Pigments or plasticizers. stirred and then poured into a greased metal well.

In the cooling process according to the precast and cooled to room temperature. To

lying invention is the liquid starting 20 minutes, the plastic mass from the trough

reaction mixture is removed in a solid, plastic state 45 in the form of a plate and remains at least

transferred, making the normal reaction workable for 6 hours,
velvet and it is possible to use the material in one

Maintain a shape appropriate to the procedure above Example 3
continue for a longer period of time. This is otherwise

not possible. The plastic nature of the cooled 50 100 parts of a ^{polyester melting at 55 0} C, material is particularly suitable for extrusion, which was made from ethylene glycol and adipic acid, spreading in the molten state and molding and having a molecular weight of about 2000, and for producing solutions or Dough and an acid number of better than 1 than 2.5, like spreading masses by dissolving in solution are dewatered for 20 minutes at 130 to 140 ⁰ C with a medium, such as ketones or chlorinated hydrocarbons, stirring at a pressure of 10 mm Hg , fabrics; Article made of rubber-synthetic resin layer- The vacuum is released and 12.1 parts of a substance can also be produced from the 65:35 mixture of 2,4- and 2,6-toluylene diiso compounds described there. Losses cyanate is added at 130 ⁰ C by cycling. Mixing will occur due to bubbling in the ordinary 30 minutes of stirring and ordinary pouring method are also excluded. 60 pressure, then 3 minutes under a pressure of When crosslinking agents, such as glycols or diamines, are heated to 20 mm Hg. The resulting liquid product to the starting liquid reaction mixture before is added by pouring it onto a cold, "smeared" cool down, then the normal well is cooled. The soft plastic reaction that forms is inhibited in a similar manner. The polyester is left to stand through a plate for 5 days at room temperature with the moisture content checked and the moisture removed, then the ethers used in the reaction become part of a 2 mm thick plate between the processing time of the made from it «Pressed stainless steel sheets, cooled material can be controlled. by this for 30 minutes at 110 ⁰ C under a

Pressure of 0.35 kg / mm ^{2 are} heated. The product is cured for 50 hours at 115 ° C and has a tensile strength of 160 kg / cm ² and an elongation at break of 818% -

5 Example 4

130 parts of a polyester which was made from ethylene glycol and a mixture of adipic acid and terephthalic acid in a molar ratio of 9: 1 and which has an acid value of 2 and a molecular weight of 1930 are 10 minutes at 140 to 150 ° C under a Pressure of 11.5 mm Hg heated and stirred to remove all traces of moisture. The temperature is then raised to 18O ⁰ C, the vacuum was broken and 0.19 parts of adipic acid and 18.7 parts of 1,5-naphthylene diisocyanate added. The mixture is heated with stirring for 5 minutes at ordinary pressure and then for an additional 5 minutes at a pressure of 11.5 mm Hg. The liquid reaction product is poured onto a cold, "lubricated" trough to cool; after it has been standing at room temperature for 1 hour, the resulting plastic film by lstündiges pressing at 110 ⁰ C and 1.05 kg / mm ² is placed in air at 1 mm thickness. After curing for a further 30 hours in a convection oven, the translucent, rubber-like film has the following properties:

Tensile strength 551 kg / cm ²

Elongation at break 800%

Modulus of elasticity at 500% elongation 183 kg / cm ²

Example 5

100 parts of polytetramethylene glycol ether with a molecular weight of 2800 are ^{heated for 10 minutes at 140 °} C. and a pressure of 10 mm Hg with stirring in order to remove traces of moisture. The vacuum is then released and 13 parts of 3-methyl-4,4'-diisocyanatodiphenylmethane are added. The mixture is for 15 minutes at ordinary pressure and stirred, and 140 to 15O ⁰ C then 4 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane was added. Then, the mixture is heated for 5 minutes at 140 to 15O ⁰ C and a pressure of 10 mm Hg with stirring and then cooled by pouring into cold, greased form. The resulting plastic plate is left to stand at room temperature for 24 hours and then molded into a U-shaped ring shape by heating at 110 ° C. for 1 hour under 0.70 kg / mm ² pressure. The rubber-like product can be easily removed from the mold and is post-cured by heating in a forced-air oven for 30 hours at 110 ° C.

Example 6

The cooled plastic material obtained in Example 4 is dissolved in a 20% strength solution in ethylene dichloride ^s. The resulting mass is a varnish that has good adhesion to polyvinyl chloride.

Claims (4)

PATENT CLAIMS: 1. A process for the production of molded articles from polyurethane elastomers by reacting one or more polyesters, polyesteramides or polyethers with an excess of a polyisocyanate while quenching the reaction mixture, characterized in that the liquid reaction mixture, which optionally contains a crosslinking agent containing at least two isocyanate-reactive groups , with the exception of one based on a reaction mass obtained from at least two polyester or polyester amide resins, of which at least one component does not melt below 182 ° C, by adding excess polyisocyanate at a temperature not more than 30 ° C below the melting point of the resin component with the highest melting point cooled below 80 ° C and then shaped and cured in a conventional manner. 2. The method according to claim 1, characterized in that the quenching to temperatures from 20 to 35 ° C. 3. The method according to claim 1 and 2, characterized in that as crosslinking glycols, more find use as dihydric alcohols or diamines. 4. The method according to claim 1 to 3, characterized in that the curing at a Temperature between 100 and 150 ° C takes place. © 109 689/231 9.61