| 摘要 |
A polyester/glyoxalated polyvinyl alcohol semi-interpenetrating polymer network hot-melt adhesive and preparation method therefore, mainly inlcudes the steps of: 1) transesterification of certain amounts of dimethyl terephthalate and another dibasic ester with 1,4-butanediol and other diols in the presence of an organotin catalyst under a nitrogen atmosphere in a reactor, completed upon the amount of distillation of a monohydric alcohol byproduct reaching greater than 95% of the theoretical amount; 2) after the temperature is maintained for a period of time, adding in a stabilizer and a polycondensation catalyst and incrementally increasing the temperature to trigger a polycondensation reaction under a reduced pressure to produce particles of a copolymer, and freezing and pulverizing the copolymer particles to produce a powder of a copolyester; 3) uniformly blending a polyvinyl alcohol/glyoxal mixture with the powder produced in step 2) at ambient temperature to produce the target product. The product is capable of forming an internal semi-interpenetrating network at application temperatures. |
| 主权项 |
1. A method for preparation of a polyester/glyoxalated polyvinyl alcohol semi-interpenetrating polymer network hot-melt adhesive, comprising the steps of
1) adding dimethyl terephthalate, another dibasic ester, 1,4-butanediol, other diols and an organotin catalyst in a reactor to conduct a transesterification reaction in a nitrogen atmosphere at a reaction temperature of 140˜180° C. with a vapor temperature maintained at 65˜90° C. and terminating the transesterification reaction when an amount of distillation of a monohydric alcohol byproduct reaches greater than 95% of a theoretical amount; 2) after the reaction temperature is maintained for a period of time, adding in a phosphite-based stabilizer and a polycondensation catalyst and increasing the temperature to 160˜240° C. to conduct a polycondensation reaction under a reduced pressure for 0.5˜1.5 hours to produce particles of a copolymer, and freezing and pulverizing the particles of the copolymer to produce a powder of the copolymer; and 3) uniformly blending a mixture of polyvinyl alcohol/glyoxal with the powder of the copolymer produced in step 2) at ambient temperature to produce the polyester/glyoxalated polyvinyl alcohol semi-interpenetrating polymer network hot-melt adhesive, wherein the another dibasic ester is selected from dioctyl phthalate, 1,6-dibutyl adipate, 1,10-dibutyl sebacate, 1,6-dimethyl adipate or dimethyl phthalate; wherein a molar ratio of dimethyl terephthalate to the another dibasic ester is 1:0.2˜0.35; wherein the other diols are one or more selected from the group consisting of ethylene glycol, 1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, neopentyl glycol and 1,3-propanediol; wherein a molar ratio of 1,4-butanediol to the other dials is 1:0.1˜0.35; wherein a molar ratio of total ester groups to total hydroxyl groups is 1:1.1˜1.8, where the total ester groups refer to ester functional groups in dimethyl terephthalate and the another dibasic ester, the total hydroxyl groups refer to hydroxyl functional groups in 1,4-butanediol and the other diols; wherein the mixture of polyvinyl alcohol/glyoxal comprises 13%˜7.5% by weight of glyoxal; and wherein the mixture of polyvinyl alcohol/glyoxal accounts for 0.2%˜0.5% by weight of the powder of the copolymer produced in step 2). |
