TDI-MDI型水性聚氨酯贴合料的制备及应用

Synthesis and application of TDI- MDI hybrid waterborne polyurethane adhesives

采用磺化聚酯二元醇(S-44)和二羟甲基丙酸(DMPA)引入复合亲水基团,以甲苯二异氰酸酯(TDI)、4-4'-二苯基甲烷二异氰酸酯(MDI)、聚己二酸乙二醇酯(PEA)、三羟甲基丙烷(TMP)等为主要原料,制备了TDI-MDI型的高固含水性聚氨酯分散体,讨论了磺化聚酯的用量、MDI/TDI比、n(NCO)/n(OH)对WPU的乳液及其胶膜性能的影响。结果表明:当n(S-44)/n(PEA)=7/3,w(DMPA)=1.4%,n(MDI)/n(TDI)=4/6,n(NCO)/n(OH)=1.50时,乳液固含量达到53.4%,黏度305c P(25℃),贮存稳定性和成膜物力学性能好。应用表明:制得的WPU贴合料可用于PU/PVC革生产线,上料量为70~80g/m^2时,PVC与涤纶基布的贴合强度达到35N/25mm以上,恒温恒湿7d后为20N/25mm以上。

Waterborne polyurethane（WPU） dispersion containing carboxylic and sulfonic groups were synthesized using poly- ester polyol containing sulfonate （S -44） and 2,2 dimethylol propionic acid （DMPA） as hydrophilic monomer and toluene diiso- cyanate（ TDI）, 4,4 - diphenyl methane diisocyanate （ MDI ）, polyethyleneglycol adipate （ PEA - 2000 ）, trimethylolpropane （TMP） as the main raw materials. The conditions influencing the quality of WPU emulsion and film were studied, such as the dif- ferent ratio of PEA/S44, the molar ratio of MDI/TDI,--NCO/--OH. The results indicate that when n （S -44）/n （PEA） --7/3, w（DMPA） = 1.4% ,n（MDI）/n（TDI） =4/6 ,n（NCO）/n（OH） = 1.50, WPU emulsion whose solid content is 53.4%, have low viscosity（305cP/25~C ）and good stability. Their films show excellent mechanical properties and low water absorptivity. The appli- cation results show that the resultant WPU binders could be used in the production line of PU/PVC leather. When the dosage of WPU is 70 -- 80g/m2, the peel strength between PVC and polyester fabric can be above 35N/25mm, and it still keeps more than 20N/25mm after tested in constant temperature and humidity for 7 days.