Process for production of oxymethylene copolymers

A technology of oxymethylene copolymerization and polymerization reaction, which is applied in the field of preparation of oxymethylene copolymers, and can solve the problems of reduced toughness, decreased productivity, low melt index and the like

Active Publication Date: 2009-08-05
MITSUBISHI GAS CHEM CO INC
View PDF1 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] However, in the process of preparing an oxymethylene copolymer having a branched chain or network structure, there is a problem that the power required in the polymerization process varies greatly due to a very small polymerization rate and a very small melt index. In order to control the required power and resin temperature, there is a problem that the productivity is significantly reduced, and the desired effect may not be satisfactory from the viewpoint of productivity.
[0010] In addition, in the case of using the above-mentioned oxymethylene copolymer having a branched or network structure alone, in order to enhance the effect of nucleation, as a problem, 1) the very small melt index as described above, 2) the approved The problem of reducing toughness in order to form high branching or network density

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Process for production of oxymethylene copolymers
  • Process for production of oxymethylene copolymers
  • Process for production of oxymethylene copolymers

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0020] In the preparation method of the oxymethylene copolymer of the present invention, comprise utilizing cationic polymerization catalyst to trioxane (A component) and the cyclic ether and / or cyclic formal (B component) that have at least one carbon-carbon bond in the ring structure ) A step of continuously polymerizing in a polymerization reaction system (polymerization step).

[0021] As a polymerization method for obtaining an oxymethylene copolymer, it is preferable to apply a bulk polymerization method that does not use a solvent substantially. This so-called bulk polymerization method refers to a polymerization method that utilizes monomers in a molten state. As the polymerization proceeds, the polymer crystallizes out in the monomer mixture, and soon the whole system becomes blocky and powdery to obtain a solid. shaped aggregates. This polymerization is preferably carried out under an oxygen-free condition, more preferably under a nitrogen atmosphere.

[0022] Cati...

Embodiment 1～7、 comparative example 1～5

[0066] An oxymethylene copolymer was produced using, as a continuous reaction apparatus, an apparatus obtained by serially connecting two of the above-mentioned continuous reaction machine and the terminator mixer in order from the raw material supply side.

[0067] Under the conditions described in the following Table 1 and Table 2, intermittently to the mixed flow of 90.0 kg / hr of trioxane (A component) and 3.8 kg / hr of 1,3-dioxolane (B component) Supply C component, further, supply the benzene solution (25 mass %) of methylal, the benzene solution (preparation concentration: 0.3mol / kg), immediately introduced into the first continuous reactor for continuous polymerization (block polymerization).

[0068] However, the supply of the C component in Example 4 was carried out so that the minimum supply rate of the C component was 0.045 mmol per 1 mol of trioxane, and the maximum supply rate was 2.2 mmol per 1 mol of trioxane. In Comparative Example 4, the C component was suppl...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

A process for the production of oxymethylene copolymers which comprises the step of polymerizing (A) trioxane with (B) a cyclic ether having at least one carbon-carbon bond in the cyclic structure and / or a cyclic formal continuously by using a cationic polymerization catalyst in a polymerization system, wherein (C) a glycidyl compound and / or an alcohol is intermittently fed to either a raw material for polymerization containing at least either of the components (A) and (B) or the above polymerization system by the early stage of the polymerization at the latest under the following conditions (1), (2) and (3): (1) the ratio (t / T) of the feed time (t) of the component (C) fed intermittently to the feed time (T) of the component (A) fed to the polymerization system is 1 / 600 to 1 / 6; (2) the feed of the component (C) in the feed time (t) is 0.4 to 50mmol per mol of the component (A); and (3) the total feed of the component (C) is 0.0004 to 0.5mmol per mol of the component (A).

Description

technical field [0001] The present invention relates to the preparation method of oxymethylene copolymer, specifically, relate to the method for continuously preparing oxymethylene copolymer. Background technique [0002] Oxymethylene copolymers have excellent mechanical and thermal properties, and are widely used as representative engineering plastics in a wide range of fields related to machinery, electricity and electronics, and automobiles. In recent years, with the expansion of the application range, the performance requirements of plastics have been improved, and the requirements for cost reduction have also been strengthened. [0003] Oxymethylene copolymer is a highly crystalline resin, and it has been confirmed that spherulites are rapidly formed in the process from a molten state to supercooling and solidification. It is recognized that the size of the spherulites affects not only mechanical properties but also various product properties such as gas permeability. ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C08G2/22
CPCC08G2/10C08G2/22C08G2/18
Inventor 冈村显长井聪
Owner MITSUBISHI GAS CHEM CO INC
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap