Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Patent
1996-06-07
1999-10-26
Niland, Patrick D.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
525399, 525400, 525401, 525402, C08L 6102, C08L 7504, C08L 6700, C08L 7700
Patent
active
059730811
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a modified polyacetal having improved affinities for various polymers, additives, fillers and the like and is useful for composite or compounded application, and excellent in secondary processabilities such as adhesion or painting (coating), and to a method of producing the same.
BACKGROUND ART
A polyacetal has excellent mechanical strength, slidability, heat resistance, chemical resistance, moldability (formability) and electrical characteristics, and hence is used as an engineering plastic in many fields. Further, a variety of performances have been practically required of such polyacetal accompanied with expanding applications.
On the other hand, the polyacetal has a high crystallinity and hence remarkably poor in affinity or compatibility for other materials. Therefore, it is difficult to modify or reform the polyacetal by means of blending and compounding with other polymers, additives or reinforcing agents and the like, and adhesive properties of the polyacetal with respect to a paint, a printing ink, a coloring agent or an adhesive can hardly be improved. By way of illustration, when an elastomer is blended with the polyacetal for improving impact resistance, satisfactory impact characteristics can not be imparted to the resultant molded article because of poor affinity and compatibility of the polyacetal for the elastomer. Further, the surface of the molded article is peeled off due to poor dispersibility of the elastomer, and hence the external appearance of the molded article is significantly sacrificed. Moreover, addition of a stabilizer, lubricant or other additive to the polyacetal for modification or reforming results in leaching of the additive to the surface of the molded article, and hence the appearance of the molded article is markedly deteriorated and functions of the additive can not be utilized effectively. Accordingly, application or use of the polyacetal may practically be limited to a great extent.
For the purpose of improving affinity of the polyacetal, it is useful to modify the polyacetal by introducing a modifying group into the polyacetal. As such modifying method of the polyacetal by introduction of a modifying group, there have been proposed a variety of technologies. By way of an example, Japanese Patent Publication No. 23467/1968 (JP-B-43-23467) proposes a process which comprises introducing an amino group into a base polyacetal with the use of aminoaldehyde as a comonomer. According to this process, however, boron trifluoride or other Lewis acid used as a polymerization catalyst is easily or readily reacted with the amino group, so that polymerization efficiency and hence characteristics as an engineering plastic are sacrificed.
Japanese Patent Publication No. 19425/1972 (JP-B-47-19425) proposes a process which comprises preparing a polymer with the use of a cyclic ether or cyclic acetal each having a nitro group as a comonomer, and reduction the resultant polymer to convert the nitro group into an amino group. However, in this process, the polymer is liable to be decomposed in the reducing step, and hence the characteristics of the obtained polymer are not satisfactorily high as an engineering plastic.
Japanese Patent Application Laid-open No. 21618/1991 (JP-A-3-21618) and Japanese Patent Application Laid-open No. 21619/1991 (JP-A-3-21619) propose production of a polyacetal copolymer having a hydroxyl group, an acyloxy group, for instance, with the use of a comonomer. Japanese Patent Application Laid-open No. 25238/1993 (JP-A-5-25238) offers a process which comprises copolymerizing trioxane and a cyclic ether or cyclic formal each having a nitrile group, a carboxyl group, an ester group or an amide group. According to these technologies, however, polymerization reactivity is poor so that a copolymer having a high molecular weight can hardly be obtained in a high yield. Japanese Patent Application Laid-open No. 93822/1991 (JP-A-3-93822) proposes a polyacetal copolymer having a nitrile group. However, this process requir
REFERENCES:
patent: 3546321 (1970-12-01), Jabloner et al.
patent: 3658912 (1972-04-01), Raimund et al.
patent: 3997613 (1976-12-01), Lenke et al.
Kanai Hiroyuki
Masuda Eiji
Ohnishi Katsuhei
Serizawa Hajime
Yamamoto Kaoru
Niland Patrick D.
Polyplastics Co. Ltd.
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