Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Post imaging process – finishing – or perfecting composition...
Reexamination Certificate
1999-02-25
2001-02-27
Dote, Janis L. (Department: 1753)
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Post imaging process, finishing, or perfecting composition...
C430S110100
Reexamination Certificate
active
06194113
ABSTRACT:
DESCRIPTION OF THE RELATED ART
The present invention relates to an olefin resin having low melting temperature for obtaining a good fixing property at low temperature, improved compatibility and strength, and to a toner comprising the same which is used in printers or copying machines utilizing heat-roll fixing.
BACKGROUND OF THE INVENTION
Recently, various improvements or modifications on coelectrophotography machines or printers utilizing electrophotography have been desired as these machines have become more popular. For example, it has been desired to reduce energy consumption in order for these machines to be practical for home use. It is also desirable to make the machines run at high speeds in order to promote the spread of the machines into so called gray areas between printers and copiers. It is also necessary to simplify the structure of the machine in order to reduce the cost of the machines. Moreover, it has become popular to use the machines having functions of printing on both sides of the printed sheet and delivering the printed sheet automatically. Of the above-described requirements, particularly desired is a toner for electrophotography (hereafter, referred to simply as “toner”) having a lower fixing temperature, a good anti-offset quality and fixing strength so that spots are not generated in a printed sheet in printing both sides of the printed sheet.
Polyolefines having a low molecular weight have generally excellent cold resistance, heat resistance, chemical resistance, abrasion resistance, and the like; therefore, they have been used as workability improvers for rubbers and plastics, dispersing agents for printing inks, abrasion resistance improvers, blocking resistance improvers, lustering agents, removers, electrical insulating materials, preservatives, and the like.
In an electrophotography field, polyolefins has received much attention as a remover among these uses; therefore, polyolefins are widely used to prevent the offset phenomenon of toners used in printers or copiers.
Moreover, in general, a polyolefin is easily handled, because its viscosity is low when it is melted. On the other hand, its compatibility with other resins and with solvents is poor; therefore, it has been desired to improve its compatibility.
Concretely, when an olefin resin is used alone in a binder resin comprising a toner as a main component, it is difficult to obtain both an anti-offset property and good fixing property. Therefore, it is impossible to use only olefin resin as a binder resin of a toner. Accordingly, when olefin resins such as styrene-acrylic copolymer and polyester resin are used as a binder resin, a remover should be mixed in at a range of 1 to 10 weight % with regard to the amount of olefin resin. However, the remover cannot be uniformly dispersed into the binder resin.
In order to solve this problem, it is suggested to improve the compatibility of olefin resin with other resins by copolymerization of olefin monomer and polar monomer, oxidative deconstituent of polyolefin, introduction of polar group by chemical denaturation, and the like.
A certain degree of its compatibility and dispersibility can be improved by introducing a polar group into polyolefin. However, it is difficult to obtain such an effect for some kinds of polyolefin.
Problems to be solved
Therefore, it is an object of the present invention to provide new olefin resin having excellent compatibility with other resins, in addition to a low melting temperature, and a low viscosity by improving conventional olefin resins. Moreover, it is also an object of the present invention to provide a toner having no offset phenomenon, and excellent fixing strength to a transfer paper by using the improved olefin resin as a binder resin of a toner.
SUMMARY OF THE INVENTION
The present invention relates to an olefin resin which is a copolymer of &agr;—olefin and at least one constituent selected from the group consisting of maleic anhydride and maleate, wherein said at least one constituent selected from the group consisting of maleic anhydride and maleate is crosslinked.
Specifically, a first embodiment of the present invention is an olefin resin which is a copolymer of &agr;—olefin and at least one constituent selected from the group consisting of maleic anhydride and maleate, wherein said at least one constituent selected from the group consisting of maleic anhydride and maleate is partially or entirely crosslinked with bivalent or greater valent epoxy compound, and a toner comprising the same.
A second embodiment of the present invention is an olefin resin which is a copolymer of &agr;—olefin and at least one constituent selected from the group consisting of maleic anhydride and maleate, wherein said at least one constituent selected from the group consisting of maleic anhydride and maleate is partially or entirely crosslinked with at least one constituent selected from the group consisting of diols and trivalent or greater valent polyols, and a toner comprising the same.
A third embodiment of the present invention is an olefin resin which is a copolymer of &agr;—olefin and at least one constituent selected from the group consisting of maleic anhydride and maleate, wherein said at least one constituent selected from the group consisting of maleic anhydride and maleate is partially or entirely crosslinked with amino compound and/or partially or entirely added amino compound by amidification reaction, and a toner comprising the same.
In the first olefin resin, an ester bond is introduced into the copolymer by a crosslinking reaction. As a result, the compatibility of the first olefin resin with other resins can be improved while a low melting temperature is maintained. The improvement of the compatibility of the first olefin resin means an improvement of the brittleness thereof. Therefore, when the first olefin resin is used as a binder resin of the toners, the brittleness of the toners can be improved while a low melting temperature, a low temperature fixing property, an anti-offset property, and a good shelf life are maintained.
An &agr;—olefin having 22 or less carbon atoms is preferable for the monomer used in ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, and 1-dococene.
An alkyl ester having 20 or less carbon atoms represented by the following formula (3) is suitable for the maleate used in the first olefin resin. For example, low dialkyl esters such as dimethyl maleate, diethyl maleate, and dibutyl maleate are preferable.
The epoxy compound has preferably 2 or greater epoxy groups. Epoxy compounds having 2 or greater epoxy groups include, for example, but are not limited to, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,4-butane diol diglycidyl ether, 1,6-hexane diol diglycidyl ether, 1,8-octane diol diglycidyl ether, glycerin diglycidyl ether, diglycidyl phthalate, glycidyl methacrylate, diglycidyl hydantoin, neopentyl glycol diglycidyl ether, trimethylol propane triglycidyl ether, glycerol polyglycidyl ether, sorbitol polyglycidyl ether, alkyl phenol diglycidyl ether, 1,2-cyclohexane diglycidyl dicarboxylate, glycidyl amine epoxide, bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, brominated novolak type epoxy resin, bisphenol F type epoxy resin, tetramethyl bisphenol type epoxy resin, bisphenol S type epoxy resin, and alicyclic epoxy resins.
Aliphatic diglycidyl ethers and aliphatic polyglycol glycidyl ethers are preferable among these epoxy compounds. In particular, aliphatic diglycidyl ethers having an alkylene chain having 2 to 10 carbon atoms other than those comprising a diglycidyl ether group are most preferable. In addition, aliphatic polyglycol glycidyl ethers comprising 1 to 100 repeating glycol units are also most preferable.
Moreover, bisphenol A type epo
Dote Janis L.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Tomoegawa Paper Co. Ltd.
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