Allophonate modified polyisocyanates
a technology of polyisocyanates and allophonates, applied in the field of polyisocyanates, can solve the problems of low nco functionality of aliphatic polyisocyanates containing uretdione groups, uretdione structure can be prone to scission under high temperature or aging, and within the coating
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Benefits of technology
Problems solved by technology
Method used
Image
Examples
example 1
[0064] Hexamethylene diisocyanate (HDI, DESMODUR® H, Bayer Materials Science, LLC, Pittsburgh, Pa.) was charged to a reactor and heated to 105° C. under a nitrogen sparge. At 105° C. a mixture of 67 g n-butanol, 55 g 1-propanol, and 60 g 1-pentanol was fed to the reactor over a 30-minute period. The mix was maintained at 105° C. for 30 minutes and then heated to 115° C. at which time 2.5 g of a 10% zinc octoate solution was added over a 1-hour period. After a 30-minute hold period, the temperature was increased to 120° C. for two hours when 0.27 g p-toluene sulfonic acid was added to the reactor and the product was stripped in TFE at 140° C. at less than 300 mTorr until all volatiles were removed. The 100% solids product had 19.4 wt. % NCO groups and a viscosity of 382 cps at 25° C. at a shear rate of 200 sec−1 and 0.08 wt. % HDI monomer. Gel permeation chromatography using polystyrene standards indicated that the HDI allophanate trimer product had a number average molecular weight ...
examples 2 and 3
[0065] Polyurethanes were prepared by combining DESMOPHEN® VP LS 2328 (polyester polyol, Bayer Materials Science) and the compound of Example 1 (Example 2) and DESMODUR® N-3400 (prior art, polyisocyanate based on HDI and containing uretdione groups, Bayer Materials Science, Example 3) at a 1:1 NCO:OH equivalent ratio, pouring the mixture into a casting plaque and allowing the composition to fully cure. The compositions were cured at standard conditions of 20° C., 50% relative humidity for at least two weeks before testing. Tensile strength and percent elongation were determined according to ASTM D-412. Split and Die “C” tear strengths were determined according to ASTM D-624. The resulting films had the following properties:
TensileElongationExampleStrength(%)Split TearDie C Tear2397.4144.47.741.23181.8 87.16.534.6Improvement119%66%18%19%
[0066] The percent improvement values indicate the superior tensile and tear properties of polyurethanes prepared using the isocyanate containing c...
examples 4 and 5
[0067] Polyurethanes were prepared by combining DESMOPHEN® VP LS 2328 (polyester polyol, Bayer Materials Science) and a 50 / 50 w / w mixture of the compound of Example 1 and DESMODUR® XP-7100N (polyfunctional isocyanate based on HDI, Bayer Materials Science; Example 4) and a 50 / 50 w / w mixture of DESMODUR® N-3400 and DESMODUR® XP-7100N (prior art, Example 5) at a 1:1 NCO:OH equivalent ratio, pouring the mixture into a casting plaque and allowing the composition to fully cure. The compositions were cured at standard conditions of 20° C., 50% relative humidity for at least two weeks before testing. Tensile strength and percent elongation were determined according to ASTM D-412. Split and Die “C” tear strengths were determined according to ASTM D-624. The resulting films had the following properties:
TensileElongationExampleStrength(%)Split TearDie C Tear4485.9119.56.7532.55281.1 84.35.4 29.7Improvement72.9%41.8%25%9%
[0068] The percent improvement values indicate the superior tensile and ...
PUM
| Property | Measurement | Unit |
|---|---|---|
| elongation | aaaaa | aaaaa |
| tensile strength | aaaaa | aaaaa |
| thicknesses | aaaaa | aaaaa |
Abstract
Description
Claims
Application Information
Login to View More