Synthesis method of polyester glycol

A technology of polyester diol and synthesis method, which is applied in the field of polyester diol, can solve the problems of large deviation between molecular weight and theoretical molecular weight, large fluctuation of product molecular weight, and change of raw material ratio, etc., and achieve mechanical properties and performance Excellent, reduced synthesis cost, cheap effect

Inactive Publication Date: 2017-06-23
ZHANGJIAGANG NANGUANG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The polyester synthesis reaction is controlled by the gradual polymerization mechanism. The feed ratio of raw materials is very important and directly determines the target molecular weight. If the loss of raw materials is caused in the synthesis process, the ratio of raw materials will change. In this way, the actual molecular weight of the product deviates greatly from the theoretical molecular weight. When unstable, the same initial feed ratio often fails to obtain qualified quality products, and the molecular weight of different batches of products fluctuates greatly

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] In a nitrogen atmosphere, add 450 g (3.08 mol) of adipic acid, 220 g (2.11 mol) of neopentyl glycol, ethylene di Mix 100g (1.11mol) of alcohol evenly, then turn on the stirrer, and heat up to 180°C at a heating rate of 100°C / h, keep the temperature until the water output reaches 34g, then continue to heat up to 210°C, then add tetramethyl titanate Ester 10ppm, continue to react until the water yield reaches 50g, and the acid value drops below 30mgKOH / g, ready for vacuum reaction;

[0031] Lower the temperature to 100°C, continue the esterification reaction, then vacuumize to remove the water generated by the reaction until the acid value drops below 1.5mgKOH / g; then lower the temperature to 80°C, and add KOH alkaline solution with a mass concentration of 20% dropwise , the dropping rate is 100ml / min, and the reaction is 1.5h; finally, the temperature is raised to above 180° C., a small amount of unreacted glycol is evaporated, and the temperature is lowered to obtain po...

Embodiment 2

[0034] In a nitrogen atmosphere, add 400 g (3.77 mol) of butylmalonic acid, 100 g (1.39 mol) of polytetrahydrofuran (PTFE), 100 g (1.39 mol) of polytetrahydrofuran, and Mix 250g (2.36mol) of diol evenly, then turn on the stirrer, and heat up to 190°C at a heating rate of 100°C / h, keep the temperature until the water output reaches 41g, continue to heat up to 220°C, add tetra-titanate Propyl ester 10ppm, continue the reaction until the water yield reaches 61g, and the acid value drops below 30mgKOH / g, ready for vacuum reaction;

[0035] Lower the temperature to 110°C, continue the esterification reaction, and then vacuumize to remove the water generated by the reaction until the acid value drops below 1.5mgKOH / g; then lower the temperature to 90°C, and add KOH alkaline solution with a mass concentration of 20% dropwise , the rate of addition is 150ml / min, and react for 1h; finally, the temperature is raised to above 180° C., a small amount of unreacted glycol is evaporated, and...

Embodiment 3

[0038] In a nitrogen atmosphere, add 200 g (1.20 mol) of terephthalic acid, 350 g (2.01 mol) of suberic acid, polypropylene glycol, Mix 220g (0.52mol) and 300g (2.58mol) of cyclohexanedimethanol evenly, then turn on the stirrer, and heat up to 190°C at a heating rate of 100°C / h, keep the temperature until the water output reaches 33g, then continue to heat up to After 230°C, add 10ppm tetraisopropyl titanate and continue the reaction until the water yield reaches 50g and the acid value drops below 30mgKOH / g, ready for vacuum reaction;

[0039] Lower the temperature to 90°C, continue the esterification reaction, and then vacuumize to remove the water generated by the reaction until the acid value drops below 1.5mgKOH / g; then lower the temperature to 60°C, and add NaOH alkaline solution with a mass concentration of 20% dropwise , the dropping rate is 200ml / min, and react for 2h; finally, the temperature is raised to above 180° C., a small amount of unreacted glycol is evaporated...

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Abstract

The invention discloses a synthesis method of polyester glycol. The synthesis method comprises the following steps: 1) carrying out normal-pressure reaction: uniformly mixing dihydric alcohol , binary acid or binary acid anhydride in a normal-pressure and nitrogen atmosphere; adding an organic titanate catalyst and carrying out the normal-pressure reaction; 2) carrying out vacuum reaction: reducing temperature to enable a mixture to be subjected to esterification reaction; vacuumizing to remove water generated by the reaction; cooling and dropwise adding an alkaline solution to reduce the acid value of the product polyester glycol; finally, raising the temperature until less unreacted dihydric alcohol is distilled out; cooling to obtain the polyester glycol which has the acid value less than 0.4mgKOH/g, the molecular weight of 800 to 3500 and the hydroxyl value of 30mgKOH/g to 100mgKOH/g and is suitable for preparing polyurethane prepolymer. According to the method disclosed by the invention, a synthesis process is subjected to quantitative treatment so that the synthesis stability is greatly improved and the acid value of the synthetic product polyester glycol is reduced.

Description

technical field [0001] The invention relates to a polyester diol, in particular to a method for synthesizing the polyester diol. Background technique [0002] Polyester polyols are very important raw materials for polyurethane chemistry and are widely used in polyurethane elastomers and foams. Polyester diol has two important characteristic parameters - acid value and hydroxyl value. The polyurethane industry hopes that the acid value should be as close to zero as possible, while the hydroxyl value can be controlled. [0003] The synthesis of polyester polyols involves two reactions, namely esterification and transesterification. Esterification is a reaction between carboxyl and hydroxyl, releasing water as a by-product, which increases the molecular weight and viscosity of the system; transesterification is a reaction between ester and hydroxyl, which does not change the average molecular weight of the system, but changes The molecular weight distribution. [0004] The e...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G63/78C08G63/85C08G63/16C08G63/672C08G63/42C08G18/42
CPCC08G63/78C08G18/4238C08G18/4252C08G18/4291C08G63/16C08G63/42C08G63/672C08G63/85
Inventor 颜迪冯向华
Owner ZHANGJIAGANG NANGUANG CHEM
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