DE1495849A1 - Process for the production of crosslinked polyurethane elastomers - Google Patents

Description

Process for the production of cross-linked polyurethane elastomers (additive to patent application F 41 483 IVd / 39 c) Subject matter of the main patent (patent application F 41 483 IVd / 59 c) is a process for the production of crosslinked polyurethane elastomers, which is characterized in that one is a mixture of linear, aromatic Amino group-containing polyaddition or condensation products with a Molecular weight from 800 to 3000, aromatic diamines having a molecular weight under 500 and diisoeyanates, if necessary by means of this, sprinkle onto a base and the implementation of the components on this document is completed. In extension this process has now been found to have the same advantage as in The main patent described the method according to the invention can also perform if one on the use of an aromatic diamine with a molecular weight waived below 500.

The linear polyaddition or aromatic amino groups containing - condensation products with a molecular weight of 800 to 3000 correspond to those of the main patent. Starting materials with a molecular weight of 800 are particularly preferred up to 1500. Compounds with a higher molecular weight require a storage time of a few hours before final hardening takes place. The mechanical The properties of the process products are nevertheless excellent. Starting from Diamino compounds with a molecular weight around 1000 are elastomers with obtained extraordinarily high tensile strengths while starting from diamino compounds with a molecular weight around 2000 the elongations at break are high. It can therefore it may be desirable to use mixtures of diamino compounds from both molecular weight ranges to use the elastomers that allow the production of their properties allow to achieve a predictable compromise of these two properties.

The diisocyanates des are suitable for the process according to the invention Main patent.

The process itself can be carried out as in the main patent.

Organic solvents are used to achieve special surface effects such as methylene chloride, ethyl acetate, trichlorofluoromethane, acetone, Dioxane or tetrahydrofuran added to the diamine component and the spraying carried out at room temperature. The cross-linked polyurethane elastomers Then, depending on the choice and concentration of the solvent, either only special smooth surfaces or even a loosened structure and accordingly a reduced volume weight.

The process products are used both for coating large-area parts as well as for spraying a wide variety of materials, such as leather, Metal, paper, wood, solid and porous plastic, cement bodies, rubber and fabrics.

Example 1 a) Production of the starting material in a stirred tank 20.0 kg (20.0 mol) of polypropylene glycol (molecular weight 1000) are dehydrated Hour by heating to 1250/15 mm. Add the solution from 6.57 at 800 kg (40 mol) of p-nitrophenyl isocyanate in about 20 liters of anhydrous chlorobenzene and continues heating to 1200 two hours. The dinitro compound can be in Quantitative presence of Raney nickel below 1000 and with 30 atm. Hydrogen pressure to reduce. After filtration from the metal, the solvent is removed together with the in the reaction generated water is distilled off.

24.85 kg (98 ffi of theory) of a dark brown remain as a residue viscous oil. The molecular weight is 1270; more than 99.3 of the end groups lie as aromatic amino groups, like titration using perchloric acid in anhydrous Shows glacial acetic acid. b) Method According to the Invention In the storage vessel of an automatic 12.68 kg of the starting material mentioned are heated to 1000 in the spray apparatus. The easily transportable liquid is mixed with a Bosch pump of about 0.5 cm3 content and fed there continuously with 2.54 kg of carbodiimide-containing 4,4'-diphenylmethane diisocyanate mixed. Since the funding the Bosch pump is about 2 kg of material per minute, there is a dwell time of just fractions of a second in the mixing head. The sprayed reaction product, however solidifies after a few seconds and remains on vertical surfaces without running, be liable.

The properties of the elastomer and the values for hydrolytic stability and hot air resistance follow from the table.

1 after 25 hours of storage at room temperature 2 after 24 hours Storage at 1000 3 after 21 days of hot water test at 1000 and 95 X rel.

Humidity 4 after 21 days of hot air test at 1250 in an air stream 1 2 3 4 Tensile strength (kp / cm2) 165 169 100 201 Elongation at break (%) 305 280 223 156 Tension (kp / cm2) (100% D) 112 142 93 188 Tension (kp / cm2) (300 ffi D) 162 - -Elasticity (%) 33 36 31 39 Shore hardness A (200) 92 95 91 92 DIN abrasion 160 70 - example 2 10 kg of the starting material are placed in the storage container of an automatic spray apparatus of Example 1 with 2.5 kg of technically pure ethyl acetate at room temperature intimately stirred. In the spray nozzle, the material is then mixed with 2.32 kg of carbodiimide-containing 4, 4-Diphenylmethane diisocyanate implemented and expelled. The elastomer adheres excellent on metal, paper, fabric, wood and plastics, on vertical walls or on the ceilings. The addition of solvent creates a very smooth, obtained glossy surface of the elastomer.

Subsequent heating of the elastomer is not necessary smaller objects but useful. The table shows the properties of the crosslinked elastomer produced in the presence of ethyl acetate.

1 after 48 hours of storage at room temperature 2 after 14 days of hot water test at 1000 and 95% rel. Air humidity 3 after 14 days of hot air test at 1000 im Air flow 1 2 3 Tensile strength (kp / cm2) 150 121 145 Elongation at break (%) 120 135 117 Modulus (100% elongation) approx. 130 106 135 Shore hardness A (200) 93 92 93 elasticity () (200) 31 30 36 Example 3 There are 20 kg of the starting material from Example 1 in the storage vessel of the spraying apparatus for one, three, five and ten Heated to 1200 hours and only then with 4 kg of 4,41-diphenylmethane diisocyanate im Implemented the spray head of the apparatus. The elastomers show in the test after 24 hours Storage at room temperature corresponding physical value level. The source material can be regarded as thermally stable.

Example 4 a) Preparation of the starting material As in Example 1 48.7 kg of polypropylene glycol (molecular weight 1,950; OH number 57.5) are added the removal of residual traces of water at 800 with the solution of 8.21 kg of p-nitrophenyl isocyanate in 50 liters of anhydrous chlorobenzene.

After reduction with Raney nickel, filtration and removal of the One receives 53.52 kg (96.5 ß d. Th.) Of a medium viscosity oil with a solvent Molecular weight of 2240 bearing more than 96.5% on aromatic amino end groups. b) Implementation According to the Invention The starting material (22.18 kg) is in the storage vessel heated to 1000 in an automatic spray system and then fed to the spray head, where it reacted with 2.66 liquid, carbodiimide-containing 4,4'-diphenylmethane diisocyanate will. The ejected material sticks to vertical surfaces, benutit but until the final state is reached, storage time of two to three hours at room temperature. The elastomer has the following physical properties: in 1 after 24 hours Storage at room temperature in 2 after 24 hours storage at 1000 1 2 tensile strength (kp / cm2) 41 55 Elongation at break (%) 550 565 Modulus (100 elongation) 26 -Modulus (300 elongation) 33 49 Elasticity (%) 36 47 Shore hardness A (200) 76 77 Using from 4 kg of tolylene diisocyanate to 22.18 kg of starting material is formed at 1100 Elastomer that can be sprayed onto vertical walls at the same time, without to run, but not as satisfactory in terms of tensile strength and elongation at break like the elastomer in the table.

When using 3.92 kg of hexamethylene diisocyanate to 22.00 kg of starting material elastomers of extraordinary elasticity are obtained.

Example 5 To 10 kg of starting material from Example 1 (OH number 88) 10 kg of starting material from Example 4 (OH number 50) are added and the mixture is increased 1000 heated. The mixture is mixed with 3.2 kg of carbodiimide-containing 4,4t -diphenylmethane diisocyanate implemented in the spray process. The elastomer remains immediately after being ejected from the Spray nozzle stand on vertical walls and harden within 20 minutes. By Mixing the two polyethers results in an elastomer that has high tensile strength the short-chain with the desired elongation at break of the long-chain starting material combined.

Column 1 after 24 hours of storage at 1100 Column 2 after 14 days Hot water test at 1000 and 95 X relative humidity column 3 after 21 days Hot air aging at 1100 in the air stream 1 2 3 2 tensile strength (kp / cm ) 135 101 111 Elongation at break (ffi) 426 525 427 Modulus (100% elongation) 81 65 92 Modulus (500% elongation) 101 68 96 elasticity (, 200) 37 37 41 Shore hardness A (200) 90 89 90 DIN Abrasion 93 Example 6 a) Production of the starting material 28 kg of a polyester from ethylene glycol and adipic acid (OH number 172) are 150 minutes at 120-130 ° / 14 mm freed from the last remnants of water. After cooling to 800, the solution will turn out 14.55 kg of p-nitrophenyl isocyanate in 45 liters of chlorobenzene were added and the reaction held at 1000 for three hours.

Small amounts of a fancy yellow body (N-p-nitrophenyl-ethane-bis-urethane) is brought into solution by adding 5 liters of tetrahydrofuran. The hydrogenation with Raney nickel takes place rapidly at 800 under 50 atmospheres of hydrogen pressure. After filtration is the solvent mixture together with the Reaction water removed in a water jet vacuum. Temperatures above 800 are to be avoided because of then onset of aminolysis of the polyester by the aromatic amino groups.

Yield 35.8 kg (90.5% of theory) of a clear, highly viscous oil with Crystallization tendency. Molecular weight 920; more than 93 of the acylatable end groups existed as an amine function. b) Implementation according to the invention In a storage vessel 10 kg of starting material with 3 liters of technically pure ethyl acetate stirred at room temperature. When spraying at 250, mixing takes place with 3 kg 4,4'-diphenylmethane diisocyanate. The reaction product remained on vertical surfaces Adheres immediately, reacts quickly to the end and has a glossy, closed surface layer. After tempering at 1000 for 24 hours, the results in the table are obtained. the Stability against hydrolysis is surprisingly good.

1 2 3 4 Tensile strength (kp / cm2) 242 292 278 166 Elongation at break (%) 90 35 35 47 Elasticity (%, 2O0) 31 35 35 32 Shore hardness A (200) 91 92 91 90 DIN abrasion 41 - - - 1 after 24 hours of storage at 1000 2 hot air test after 2 weeks at 110 ° in a stream of air, 3 hot air test after 3 weeks at 110 ° in a stream of air 4 Hot water aging after 7 days at 1009 and 95% relative humidity Example 7 a) Preparation of the starting material 23.4 kg of one are placed in a stirred kettle Polyester from 1,3-propanediol and adipic acid (OH number 56) after thorough Drain with the solution of 3.92 kg of p-nitrophenyl isocyanate in 20 liters of chlorobenzene at 1000 µm. After reduction of the dinitro compound, filtration and removal of the Solvent remains 24.1 kg 91% d. Th.) A dark brown viscous oil, that slowly crystallizes. Molecular weight 2280; more than 96% of the acylatable End groups exist as an amine function. b) Implementation according to the invention by means of a automatic atomization machine are 10 kg of starting material at 800 with 1.2 kg 4,4'-Diphenylmethane diisocyanate implemented. The elastomer shows rapid solidification and after 24 hours of storage at room temperature the following properties: tensile strength 82 kp / cm2, elongation at break 545%, tensile stress at 100 elongation 52 kp / cm and 66 kp / cm2 at 300% elongation, elasticity of 35% with a Shore hardness A of 84 and Din abrasion von 95. c) Implementation according to the invention The mixture (1: 1) from the polyester of the example 6 (OH number 122.5) with the above-mentioned polyester with OH number 49 results in after Spray when 2.1 kg of carbodiimide-containing 4,41-diphenylmethane diisocyanate per 10 kg of polyester mixture are used, an elastomer with excellent technical properties. Liability Anything like paper, fabric, metal, cement and wood is good for that The surface is smooth and glossy.

Column 1 after 24 hours of storage at room temperature after column 2 Storage for 24 hours at 110 ° column 3 after hot air aging for 3 weeks at 100 ° Column 4 after 14 days of hot water test at 100 ° and 95% rel. Humidity 1 2 3 4 Tensile strength (kp / cm2) 102 111 185 65 Elongation at break (%) 67 83 222 40 Elasticity (%) 30 31 38 35 Shore hardness A (200) 94 93 97 96 DIN abrasion 117 60--

Claims (1)

Claim method for the production of crosslinked polyurethane elastomers, wherein a mixture of linear, aromatic amino groups containing polyaddition or condensation products with a molecular weight of 800 to 3000, aromatic Diamines with a molecular weight below 500 and diisocyanates if necessary by means of Sprayed nozzles on a surface and the implementation of the components on this Document completed, according to patent. (Patent application F 41 48 IVd / 39 c) characterized in that one only a mixture of linear polyaddition containing aromatic amino groups or condensation products with a molecular weight of 800 to 3000 and diisocyanates used.