A kind of preparation method and application of stable NDI prepolymer

A prepolymer and closed prepolymer technology, applied in the field of polyurethane elastomers, can solve problems such as unstable production process, high NDI activity, and decreased NCO content, and achieve excellent dynamic mechanical properties and heat resistance, and improve Effects of degree of microphase separation and storage stability at low and high temperatures

Active Publication Date: 2022-07-08
WINSIN MATERIALS INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, NDI has high activity, and the stability of the synthesized prepolymer is extremely poor. Generally, it needs to be used within 30 minutes in the production process, otherwise it will cause a decrease in NCO content, an increase in material viscosity, and a decrease in performance, etc.
[0003] Patents such as CN106414539A and CN103608374B disclose methods for preparing NDI prepolymers by rapid cooling. The prepolymers can be stored stably for 6 months at room temperature, but the production process is complicated and the cost is high.
The CN106632980A patent discloses the use of catalyst-free polyester polyols and adding an appropriate amount of antioxidants during the synthesis process to prepare NDI-polyester prepolymers with stable NCO content after 6 months of storage at room temperature, but the range of raw materials used Narrower, the product has poor hydrolysis resistance
The CN105837788A patent discloses the use of cetyl alcohol to reduce the reactivity of NDI, and the addition of wax to reduce the viscosity and shear force of the prepolymer to prepare NDI prepolymers that can be stored at room temperature for 6 months, but the process is required by NDI. High-temperature melting, and NDI is prone to deterioration during high-temperature melting, which can easily cause instability in the production process

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] 1. Preparation of NDI primary prepolymer P-1: add 500 parts by weight of dry PTMG1000 to a drying flask, heat to 100° C., add 352 parts by weight of NDI powder, after the NDI is completely dissolved, add 500 parts by weight of dry PTMG1000, The reaction was carried out at 90° C. for 15 min to obtain the primary prepolymer P-1.

[0029] 2. Preparation of closed-type prepolymer F-1: add 313 parts by weight of dry NP to the above-mentioned primary prepolymer P-1, and continue to react at 90° C. for 2 hours until there is no residual NCO group to obtain a closed-type prepolymer. Body F-1.

[0030] 100 parts by weight of the prepared closed prepolymer F-1 and 10.3 parts by weight MOCA were mixed uniformly at 90 ° C, poured into a mold at 100 ° C after vacuum defoaming, and demolded after vulcanization for 24 hours to obtain polyurethane elasticity body.

Embodiment 2

[0032] 1. Preparation of NDI prepolymer P-2: add 600 parts by weight of dry PTMG2000 to a drying flask, heat it to 100°C, add 208 parts by weight of NDI powder, after the NDI is completely dissolved, add 400 parts by weight of dry PTMG2000, and at 90 The reaction was carried out at °C for 25 min to obtain the primary prepolymer P-2.

[0033] 2. Preparation of closed-type prepolymer F-2: add 226 parts by weight of dry NP to the above-mentioned primary prepolymer P-2, and continue the reaction at 90° C. for 2 hours until there is no residual NCO group to obtain a closed-type prepolymer. Body F-2.

[0034] 100 parts by weight of the prepared closed prepolymer F-2 and 8.6 parts by weight of MOCA were mixed uniformly at 90 ° C, poured into a mold at 100 ° C after vacuum defoaming, and demolded after vulcanization for 24 hours to obtain polyurethane elasticity body.

Embodiment 3

[0036] 1. Preparation of NDI prepolymer P-3: add 500 parts by weight of dry CAPA2101A to a drying flask, heat it to 110° C., add 403 parts by weight of NDI powder, after the NDI is completely dissolved, add 500 parts by weight of dry CAPA2101A, and put it at 90 The reaction was carried out at °C for 20 min to obtain the primary prepolymer P-3.

[0037] 2. Preparation of the closed prepolymer F-3: add 425 parts by weight of dry NP to the above primary prepolymer P-3, and continue the reaction at 90°C for 2.5 hours until there is no residual NCO group to obtain a closed prepolymer. Aggregate F-3.

[0038] 100 parts by weight of the prepared closed prepolymer F-3 and 10 parts by weight of HQEE were mixed uniformly at 120 ° C, poured into a mold at 120 ° C after vacuum defoaming, and demolded after vulcanization for 24 hours to obtain polyurethane elasticity body.

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Abstract

The invention discloses a preparation method and application of a stable NDI prepolymer, which is characterized in that NDI powder is added to part of oligomer polyol at one time, and the remaining oligomers are added in batches after complete dissolution The polyol is reacted to obtain the NDI primary prepolymer P; then the primary prepolymer P is subjected to a blocking treatment with a blocking agent to obtain the blocked prepolymer F. The method of batch feeding in the present invention reduces the proportion of macromolecular compounds, improves the regularity of the molecular structure, and thus reduces the viscosity of the NDI primary prepolymer; The reasons for the instability of NDI prepolymers were investigated, thereby improving the storage stability of NDI prepolymers, especially the storage stability at high temperature. The polyurethane elastomer prepared from the prepolymer has a very good degree of microphase separation and good mechanical strength.

Description

technical field [0001] The invention relates to the technical field of polyurethane elastomers, in particular to a stable NDI prepolymer and a preparation method and application thereof. Background technique [0002] Polyurethane elastomer is a special polymer synthetic material with adjustable hardness. It has excellent wear resistance, good physical and mechanical properties, medium resistance, ozone resistance and other properties, so it is widely used in rollers, seals and other fields. Due to the symmetry and rigidity of the molecular structure of 1,5-naphthalene diisocyanate (NDI), the prepared polyurethane elastomer has excellent dynamic properties and wear resistance, and has high mechanical strength, low damping, high resilience, and endogenous heat. It can be used in high dynamic load and heat-resistant occasions. However, NDI has high activity, and the synthesized prepolymer has extremely poor stability. Generally, it needs to be used within 30 minutes in the pr...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G18/80C08G18/76C08G18/48C08G18/10C08G18/32
CPCC08G18/8067C08G18/7678C08G18/4854C08G18/10C08G18/3814
Inventor 袁军王功海彭威周军
Owner WINSIN MATERIALS INC
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