Claims
- 1. A methacrylimide containing polymer comprising from 2 to 100% by weight of a structural unit represented by the general formula (I): ##STR4## where R represents a hydrogen atom or an aliphatic group, aromatic group or cycloaliphatic hydrocarbon group with 1 to 20 carbon atoms and from 0 to 98% by weight of a structural unit derived from an ethylenic monomer, the polymer having:
- (a) a molecular weight (Mw) of greater than 50,000 and less than 200,000 as measured by GPC,
- (b) an amount of amide segments in the polymer of less than 5% by weight,
- (c) a yellowness index (YI.sub.0) of 3 or below,
- (d) a yellowness degree (.DELTA.YI) of 3 or below,
- (e) an iron content in the polymer of less than 20 ppm, and
- (f) a content of fine particles sized from 0.5 .mu.m to 25 .mu.m in the polymer as measured by a fine particle counter of less than 50,000/g of the polymer,
- said polymer having been prepared by a process wherein
- an inert gas is introduced into methyl methacrylate or a mixture of methyl methacrylate and an ethylenic monomer copolymerizable with the methyl methacrylate to reduce the amount of dissolved oxygen,
- polymerization or copolymerization of methyl methacrylate, imidization of the polymer or copolymer of methyl methacrylate to form a methacrylimide containing polymer, and separation of volatile materials from the methacrylimide containing polymer are carried out continuously.
- 2. A methacrylimide containing polymer as defined in claim 1, wherein an amount of low molecular weight amide derivatives as a volatile ingredient in the polymer is less than 1000 ppm and an amount of residual monomers as the volatile ingredient in the polymer is less than 500 ppm.
- 3. A methacrylimide containing polymer as defined in claim 1, wherein a distribution range for an imidization ratio of the polymer is 5 % or below.
- 4. A methacrylimide containing polymer comprising from 2 to 100 % by weight of a structural unit represented by the general formula (I): ##STR5## where R represents a hydrogen atom or an aliphatic group, aromatic group or cycloaliphatic hydrocarbon group with 1 to 20 carbon atoms and from 0 to 98 % by weight of a structural unit derived from an ethylenic monomer, the polymer having
- (a) a molecular weight (Mw) of greater than 50,000 and less than 200,000 as measured by GPC and
- (b) an amount of amide segments in the polymer of less than 5% by weight and
- wherein the distribution range for the imidization ratio of the polymer is 5% or below.
Priority Claims (1)
Number |
Date |
Country |
Kind |
63-334725 |
Dec 1988 |
JPX |
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Parent Case Info
This application is a continuation-in-part continuation division of application Ser. No. 07/461,337, filed on Dec. 28, 1989, now abandoned.
US Referenced Citations (6)
Continuations (1)
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Number |
Date |
Country |
Parent |
461337 |
Dec 1989 |
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