DE1076359B - Process for the production of rubber-elastic plastics - Google Patents

Description

It is known to produce rubber-elastic plastics by the isocyanate polyaddition process. A storable elastomer can be obtained which corresponds to the raw rubber and which is then treated with a diisocyanate or with other crosslinking agents, e.g. B. with formaldehyde or with peroxides, can be "vulcanized". Rubber-like polyurethanes are also notable for the fact that moldings can be produced from them in the casting process, which makes it possible to produce moldings of complex design without any problems and without loss of material. This casting process is carried out in such a way that polyhydroxyl compounds with a molecular weight above 800 are reacted with an excess of organic diisocyanates and then a compound with at least two reactive hydrogen atoms and a molecular weight below 800 ¹ in one to react with the free NC O groups of the isocyanate-modified polyhydroxyl compounds mixed in insufficient amount. This mixture is pourable; after pouring it is allowed to react with shaping (cf. German patent 831772).

It is also already known in the production of such rubber-elastic materials according to the Casting process oxidizing agent, e.g. B. organic peroxides, to be used in the shaping implementation. This ensures a quick and smooth reaction even in closed molds (see British Patent 748,697).

The present invention is now an improvement of this process for the production of rubber-elastic plastics by reacting polyhydroxyl compounds with a molecular weight above 80O ¹ with an excess of organic diisocyanates and then mixing in a "compound with at least two reactive hydrogen atoms and a molecular weight below 800 in one for Reaction with the free NC O groups of the isocyanate-modified polyhydroxyl compounds in an insufficient amount and subsequent hardening of the mass in the presence of organic oxides with shaping Contains C = C bonds.

The process products obtainable in this way differ from those previously known in the casting process accessible materials by maintaining the well-known good mechanical Properties a better hydrolysis resistance, heat resistance and especially a larger one Have solvent resistance. You let yourself

Method of manufacture
rubber-elastic plastics

Applicant:

Paint factories Bayer Aktiengesellschaft, Leverkusen-Bayerwerk

Dr. Erwin Müller, Dr. Karl Ludwig Schmidt

and Dr. Günther Nischk, Leverkusen,

have been named as inventors

for example in dimethylformaldehyde, which is one of the best solvents for polyurethane plastics represents, no longer dissolve and this alone differs from the usual rubber-elastic Polyurethane plastics, including those made by the aforementioned method of the British Patent 748,697 are made.

From the German patent specification 938 933 it is already known to produce crosslinked, highly elastic products to produce mixtures of saturated and unsaturated linear polyesters with free OH groups Reacts with an excess of diisocyanates and expediently after reacting with causes the diisocyanates subsequent crosslinking by adding polymerization accelerators. A chain extender or crosslinking agent, such as a glycol or a diamine, is used not used. This process does not allow harder rubber-elastic materials to be produced.

From British patent specification 776 979 it is known to use elastomers via a storable intermediate stage to produce, which has free OH groups and which under shaping with organic peroxides is cured. A casting process of the type described herein, however, is used with milder ones Temperatures carried out as a »vulcanization« of a storable intermediate stage by means of peroxides. For example, polyhydroxyl compounds with a molecular weight above 800 are predominant linear polyesters, polyester amides, polyethers, polythioethers or polyacetals. The most suitable Materials have a molecular weight of about 1000 to 5000 and O numbers between "30 and 80 with an acid number below 2 if possible.

909 757/517

3 4

Unsaturated groups required according to the invention in Example 1

of the polyhydroxyl compound, one will In 200 parts by weight of a glycoladipic acid poly-

It is advisable to start from unsaturated polyesters, esters (OH number 56) are after dehydration

which, for example, maleic acid and fumaric acid, at 130 ° C / 12 mm 60 parts by weight of 1,5-naphthylene

contained condensed. 5 stirred in diisocyanate. The temperature is raised

As diisocyanates in excess with these to 135 to 140 ° C and leaves after about 20 minutes

Polyhydroxyl compounds are to be reacted, cool to 120 ° C. Be at this temperature

are above all 1,5-naphthylene diisocyanate, 1,4-naph- 14.2 parts by weight of butenediol and then 8 parts

ethylene diisocyanate, 4,4'-diphenylmethane diisocyanate, parts by weight of dicumyl peroxide are stirred in. One pours in

p-phenylene diisocyanate, toluene diisocyanate and hexaio forms and post-heats for 24 hours at 100 ° C,

methylene diisocyanate mentioned. It should also be noted that the resulting highly elastic product is in

on boiling dimethylformamide containing ester groups after a boiling time

Polyamines produced by phosgenation of 15 minutes still unchanged, while a material

isocyanates. Unsaturated diisocyanates are z. B. rial, which as a comparative product without the

those obtained by reacting 1 mole of butenediol with 15 use of peroxide, according to the

2 moles of a diisocyanate have been prepared. completely resolved at the same time.

At compounds with at least two reactive The material crosslinked by means of peroxide possesses

capable hydrogen atoms and a molecular following mechanical properties:
weight below 800 are, for example, 1,4-butanediol,

Quinite, hydroquinone - ^ - dioxäthylether, 1,5-naphtha- 20 tensile strength 225 kg / cm

lin - /? - dioxäthylether, dioxäthylanilin, 3,3'-dichlor- elongation at break 425%

benzidine, S.S'-dichloro - ^ '- diamino-diphenylmethane. so- load at 300% elongation 130 kg / cm ²

such as 2,5-dichloro-p-phenylenediamine mentioned. Instead of Shore hardness 85 °

of glycols and diamines one can also find amino elasticity (DIN 53 512) 37%

use alcohols. 25 permanent elongation 10%

The unsaturated C = C or C = C bonds

one is expediently with the help of the connections.

with a molecular weight below 800 in the reaction conditions the following proportions

introduction mixture, although it is also chosen without: 200 parts by weight of glycoladipic acid poly-

further is possible, e.g. B. of one of the above 3 ° ester (OH number 56), 80 parts by weight of 1,5-naphthy

ten unsaturated polyester or both lene diisocyanate, 22.6 parts by weight of butenediol and

an unsaturated polyester as well as an unsaturated 8 parts by weight dicumyl peroxide, then a di-

saturated compound having a molecular weight below methylformamide insoluble material having the following

800 to be used. The more unsaturated bonds obtained in the properties:

If the reaction mixture is present, the higher it becomes- 35 Tensile strength 235 kg / cm *

in addition to crosslinking via isocyanate groups with an elongation at break of 550%

Degree of polymerisation of the rubber-elastic synthetic? Ολή «Ί" τ ^ \ ' ...., - ,, *, »

substance, whereby the solvent and heat load at 300 «/» elongation 148 kg / cm *

resistance of the product can vary. Un- Shore hardness 94

saturated compounds with a molecular weight of 4 ° elasticity 39%

below 800 are for example 1,4-butynediol, 1,4-butene- permanent elongation 10%

diol, fumaric acid diglycol ester, allyl monoglycerol-. .

ether or the reaction product of 2 moles of example Δ

Hydroquinone-yff-dioxäthylether with 1 mole of fumaric acid. A mixture of 160 parts by weight of a GIy-

The reaction of the polyhydroxyl compound with ⁴⁵ koladipic acid polyester (OH number 56) and 40 Geeinem molecular weight over 800 with the organic parts by weight of a diisocyanate see through esterification of 5 moles expediently takes place from adipic acid, 1 mole of fumaric acid and 6.5 moles of glycol Moisture at elevated temperatures, unsaturated polyester obtained (OH number 45; best between 80 and 150 ° C. The excess acid number 1) is dehydrated at 130 ° C / 12 mm, the diisocyanate is advantageously in the range between 5 ° Then 60 Parts by weight of 1,5-naphthylenediiso-20 and 700% above the amount that stirred in cyanate for the reaction. The temperature is increased to 135 ° to 140 ° C. with the OH groups of the polyhydroxyl compound, and after about 20 minutes the temperature is increased as required. Cool the compound with a mole of 120 ° C. At this temperature the weight is below 800, 14.4 parts by weight of butanediol and then 8 parts by weight are added in such a way that the excess of 55 parts by weight of dicumyl peroxide is stirred in. Pouring into NCO groups does not completely disappear. Same shape and heats up for another 24 hours,
Organic peroxides are added in good time. The material obtained is after boiling for 5 hours

Suitable organic peroxides are di-tert-butyl not dissolved in dimethylformamide, while the im

peroxide, cumyl hydroperoxide, dibenzoyl peroxide, comparison test produced, not loaded with peroxide

tert-butyl perbenzoate and in particular dicumyl ^perbenzoate acted completely after 15 minutes

oxide. The peroxides are preferred in the amounts that have gone into solution.

from 1 to 10%, based on the reaction mixture, The material crosslinked with peroxide has the following

used. mechanical properties:

The mixture is briefly and thoroughly transit _"r. ,. . _ori , "

stirred and in the pourable liquid state in the 6 ₅ tensile strength 189 kg / cm *

Form introduced, in which the mass to rubber- elongation at break 255%

elastic plastic expediently under further load at 300% elongation 141 kg / cm ²

The application of heat hardens. The molded pieces obtained Shore hardness 90 °

as usual, the final elasticity is 45% through free reheating

hardened. 7 ° permanent elongation 14%

5 6

EXAMPLE 3 Tes _of polyhydroxy compounds with a molecular weight of 200 parts by weight of the molecular weight described in Example 2 above 800 and an excess of ester mixture are dehydrated at 130 ° C./12 mm. of organic diisocyanates with a minimum of 60 parts by weight of 2,4-tolylene diisocyanate are then stirred in, two reactive hydrogen atoms and cyanate. The temperature is raised to 135 ° to 140 ° C., which has a molecular weight below 800, and after 20 minutes the compound is allowed to cool to 120 ° C. in order to react with the free. 58.8 parts by weight of 4,4'-di-NCO groups of the isocyanate-modified polyamino-3,3'-dichlorodiphenylmethane and then insufficient amount of hydroxyl compound and 8 parts by weight of dicumyl peroxide are then stirred in. Then subsequent curing of the mass in counter-pouring, it is poured into molds and heated for a further 24 hours at xo wart of organic peroxides below mold -100 ° C. It is insoluble in dimethylformamide, characterized in that at least one plastic body is produced which uses at least one resin-building component and has mechanical properties: the unsaturated C = C or C ^ C bonds

Tensile strength contains 185 kg / cm ² .

Elongation at break 170% ¹ S.

Shore hardness 95 ° _ _ - ^,

Elasticity 36% Publications considered:

Permanent elongation 16% British Patent No. 776,979.

Claims (1)

Claim: ₂₀ A process for preparing rubber-elastic ^Contemplated older patents: Plastics by implementing the reaction product- German Patent No. 1 051 491. © 909 757/517 2.60