Polyurethane curing agent compounded by diphenylmethane diisocyanate and hydroxyl compound

A technology of polyurethane curing agent and diisocyanate, applied in the direction of polyurea/polyurethane coatings, coatings, etc., can solve the problems of reactivity, difficult construction activation period, poor storage stability, low hardness of paint film, etc., and achieve excellent use characteristics, Good stability and high film hardness

CN101955575AActive Publication Date: 2011-01-26CARPOLY CHEM GRP
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2011-01-26
Patent Text Reader

Abstract

The invention discloses a polyurethane curing agent compounded by diphenylmethane diisocyanate and hydroxyl compounds, which comprises the following raw materials in parts by weight: 28 parts to 33 parts of diphenyl-methane-diisocyanate (MDI) monomer, 1.5 parts to 2 parts of trimethylolpropane, 0.5 part to 1.5 parts of propanediol, 22 parts to 26 parts of hydroxyl polymer compound, 0.5 part to 1 part of butyl cellosolve, 0.05 part to 0.1 part of dibutyltin dilaurate, 6 parts to 9 parts of acetic ether, 6 parts to 9 parts of butyl acetate, 8 parts to 12 parts of dimethylbenzene and 8 parts to 12 parts of methylbenzene. The invention has the advantages that free MDI is low, and the polyurethane curing agent has high stability when being stored at high and low temperature and does not turn white in high-wet weather; NCO in the curing agent is high, and when the polyurethane curing agent is in cross-linking reaction with paint components containing the hydroxyl group, the reaction activity and the construction activation period can be met simultaneously, and the harness of paint films is higher; and the polyurethane curing agent can form into coating films of different characteristicsafter normal temperature copolymerization by matching with the paint components containing the hydroxyl group. The invention has very excellent use characteristic and wide application fields.
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Description

technical field

[0001] The invention relates to a polyurethane curing agent, in particular to a polyurethane curing agent synthesized from diphenylmethane diisocyanate and hydroxyl-containing compounds and a preparation method thereof. Background technique

[0002] At present, when curing agent manufacturers manufacture diphenylmethane diisocyanate (MDI) polyurethane curing agents, most of them use pure 2,4-body diphenylmethane diisocyanate monomer or modify 2,4-body diphenylmethane with carbodiimide. Diisocyanate monomers react directly with trimethylolpropane or some hydroxyl-containing polymer compounds to synthesize polyurethane curing agents. This kind of curing agent has many disadvantages: the free diphenylmethane diisocyanate (MDI) of the curing agent is high, the storage stability is poor, and it is easy to turn white in high humidity weather; the NCO of the curing agent is low, and it interacts with the hydroxyl-containing paint components In the case of combined ...

Examples

preparation example Construction

[0028] The preparation method of diphenylmethane diisocyanate and hydroxyl compound synthetic polyurethane curing agent, it comprises the steps:

[0029] (1), drop into MDI monomer, trimethylolpropane, propylene glycol, hydroxyl-containing macromolecule compound, ethyl acetate and butyl acetate successively by the amount of above-mentioned parts by weight in reaction vessel, then stir and heat up; Reaction vessel can It is a four-necked flask equipped with a thermometer, a condenser, and a stirring paddle, and the heating can be heated by heating oil;

[0030] (2), heat up to 60-70°C within 30-45 minutes, and keep warm for 0.5-1.5 hours;

[0031] (3), add ethylene glycol butyl ether, and the heating oil heats up;

[0032] (4), heat up to 80-90 DEG C in 20-30 minutes, keep warm for 2-3 hours;

[0033] (5) Cool down to 65-75°C in 20-30 minutes, add dibutyltin dilaurate catalyst, and keep warm at 65-75°C for 1.5-2.5 hours;

[0034] (6) Cool down to 40-50° C. to filter and disc...

Embodiment 1

[0036] The polyurethane curing agent synthesized by diphenylmethane diisocyanate and hydroxyl-containing compounds is mainly made of raw materials including the following parts by weight: diphenylmethane diisocyanate (MDI) monomer: 28; trimethylolpropane: 1.5; propylene glycol: 0.5 ;Hydroxyl-containing polymer compound: 22; Ethylene glycol butyl ether: 0.5; Dibutyltin dilaurate: 0.05; Ethyl acetate: 6; Butyl acetate: 6; Dimethyl carbonate: 6; :8.

Embodiment 2

[0038] The polyurethane curing agent synthesized by diphenylmethane diisocyanate and hydroxyl-containing compounds is mainly made of raw materials including the following parts by weight: diphenylmethane diisocyanate (MDI) monomer: 33; trimethylolpropane: 2; propylene glycol: 1.5 ; Hydroxyl-containing polymer compound: 26; Ethylene glycol butyl ether: 1; Dibutyltin dilaurate: 0.1; Ethyl acetate: 9; Butyl acetate: 9; Dimethyl carbonate: 9; Xylene: 12; :12.