Blocked polyisocyanate
a polyisocyanate and polyisocyanate technology, applied in the field of blocked polyisocyanate, can solve the problem of limited usefulness in the coating area
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Benefits of technology
Problems solved by technology
Method used
Examples
example 1
[0014] A 500 ml round bottom flask fitted with stirrer, nitrogen inlet, condenser and thermocouple was filled with 86.53 grams (1.0 equivalent) of NTI and 9.18 grams (0.2 equivalent) of 1,3-butanediol. The reaction mixture was heated with stirring to 85° C. and held for two hours at which time the NCO content was 35.20% by weight (theoretical 35.11%). The reaction mixture was cooled to room temperature and 31.85 g methyl propyl ketone and 77.04 grams (0.8 equivalent) of 3,5-dimethyl pyrazole was added. The reaction mixture had a strong exotherm and an ice bath was used to keep the temperature to no higher than 65° C. When the exotherm was complete, heat was applied to maintain a reaction temperature of 60° C. The 60° C. reaction temperature was maintained for four hours when an IR spectrum showed no isocyanate remaining. The solids were 85% and the viscosity was >100,000 cps @ 25° C. The isocyanate content of the solution was 256 g / eq. No crystals formed after one month, even after ...
example 2
[0015] The procedure of Example 1 was used except that 87.37 grams (1.0 equivalent) of NTI, 14:97 grams (0.33 equivalent) of 1,3-butanediol, 30.21 grams of methyl propyl ketone and 64.57 grams (0.67 equivalent) of 3,5-dimethyl pyrazole were used. The isocyanate content of the adduct was 27.8% by weight (theoretical 27.5%). The final product had a solids content of 85% and the viscosity was >100,000 cps @ 25° C. The isocyanate content of the solution was 294 g / eq. No crystals formed after one month, even after seeding with pure DMP blocked NTI from Comparison Example 1.
example 3
[0018] A paint formulation was prepared from 39 grams of the blocked isocyanate of Example 1, 100 grams of Desmophen A870 BA, 0.2 grams of Byk 306, 0.2 grams of Byk 358 and 34.7 grams of a mixture of n-butanol:propylmethyl ether acetate:3-ethoxypropanoic acid ethyl ester (4:5:6 weight ratio). When the DMP adduct of NTI 2 was used, the formulation was adjusted for the NCO content.
[0019] Desmophen A870 BA is an acrylic polyol at 70% solids in butyl acetate, having an OH number of 97 and a viscosity at 23° C. of 3500 cps, available from Bayer Polymers LLC. Byk 306 is a silicone surfactant, available from Byk Chemie. Byk 358 is an acrylic leveling additive, available from Byk Chemie.
[0020] The clear coating was drawn down with a 3 mil draw down bar on an e-coated steel panel and cured at 285° C. for 30 minutes.
[0021] The results are given in the following table.
DMP adduct of NTIDMP adduct of NTITestprepolymer 1prepolymer 2Equivalent weight,294216g / eqMEK double rubsPass 100Pass 100A...
PUM
| Property | Measurement | Unit |
|---|---|---|
| temperatures | aaaaa | aaaaa |
| temperatures | aaaaa | aaaaa |
| reaction temperature | aaaaa | aaaaa |
Abstract
Description
Claims
Application Information
Login to View More