What is claimed is:
1. An image forming apparatus, comprising:
an image carrier;
charging means for charging said image carrier and residual toner on said image carrier;
charging bias applying means adapted for regulating a charging bias applied to said charging means;
electrostatic image forming means for forming an electrostatic image on said image carrier charged by said charging means;
developing means for collecting the residual toner on said image carrier and visualizing said electrostatic image;
developing bias regulating means for regulating a developing bias applied to said developing means;
image ratio calculating means for calculating an image ratio on the basis of the electrostatic image formed on said image carrier; and
regulating means for regulating a contrast potential between the developing means collecting the residual toner and said image carrier on the basis of a calculation result of said image ratio calculating means.
2. The apparatus according to claim 1, wherein said regulating means regulates the charging bias applied by said charging bias applying means.
3. The apparatus according to claim 1 or 2, wherein said developing means has a magnetic brush comprising at least magnetic carriers and toner and said magnetic brush is in contact with said image carrier.
4. The apparatus according to claim 3, wherein a surface rotational moving direction of said image carrier differs from a rotating direction of the developer carrier carrying said magnetic brush.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A flame retardant composition comprising
A. a thermoplastic vulcanizate composition comprising:
1. from about 15 to about 75 weight percent of a continuous phase comprising at least one thermoplastic polyester, and
2. from about 25 to about 85 weight percent of a dispersed phase comprising at least one peroxide-cured elastomer selected from the group consisting of polyacrylate rubbers, polymethacrylate rubbers, polyethylenepolyacrylate rubbers, and polyethylenepolymethacrylate rubbers; wherein said rubber is dynamically crosslinked with at least one peroxide free radical initiator and at least one organic multiolefinic co-agent;
\u2003the weight percentages of the continuous phase and the dispersed phase being based on the total combined weight of the continuous and dispersed phases,
B. from about 1 to about 30 weight percent, based on the total weight of the flame retardant composition, of at least one flame retardant selected from the group consisting of phosphinates of formula I, diphosphinates of formula II, polymers thereof and combinations of two or more thereof
\u2003wherein R1 and R2 are independently selected from the group consisting of hydrogen, linear or branched C1-C6 alkyl groups, and aryl groups; R3 is a linear or branched C1-C10-alkylene group, a C6-C10-arylene group, a C6-C10-alkylarylene or a C6-C10-arylalkylene group; M is a metal ion selected from the group of calcium ions, magnesium ions, aluminum ions, zinc ions, and mixtures thereof, m is 2 to 3; n is 1 or 3; and x is 1 or 2 with the proviso that when m is 2, then x and n are each 1, and when m is 3, x is 2 and n is 3; and
C. from about 0.05 to about 1.75 weight percent, based on the total weight of the flame retardant composition, of an ultra-high molecular weight polysiloxane.
2. A flame retardant composition of claim 1, wherein the ultra-high molecular weight polysiloxane is an ultra-high molecular weight polysiloxane of the formula
wherein R1, R2, R3, R4, R5, R6, R7 and R8 are identical or different and are selected from the group consisting of alkyl, vinyl, chloroalkyl, fluororalkyl, aminoalkyl, epoxy, chloro, fluoro, and hydroxy groups, and a is 500 or greater.
3. A flame retardant composition according to claim 2, wherein the ultra-high molecular weight polysiloxane is a polydimethylsiloxane of the formula
wherein R1 and R2 are identical or different and are selected from the group consisting of alkyl groups, vinyl groups, chloroalkyl groups, aminoalkyl groups, epoxy groups, fluororalkyl groups, chloro groups, fluoro groups, and hydroxy groups, and wherein a is 500 or greater.
4. A flame retardant composition of claim 1, wherein the ultra-high molecular weight polysiloxane is a polydimethylsiloxane of formula
wherein a is 1350 or greater.
5. A flame retardant composition of claim 1, wherein the at least one flame retardant is selected from the group consisting of aluminum methyl ethyl phosphinate, aluminum diethyl phosphinate and zinc diethyl phosphinate.
6. A flame retardant composition of claim 1, wherein the at least one free-radical initiator is selected from the group consisting of 2,5-dimethyl-2,5-di-(t-butylperoxy)hexyne-3, t-butyl peroxybenzoate, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane, dicumyl peroxide, \u03b1,\u03b1-bis(t-butylperoxy)-2,5-dimethylhexane and mixtures thereof.
7. A flame retardant composition of claim 1, wherein the at least one organic multiolefinic co-agent is selected from the group consisting of diethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, N,N\u2032-m-phenylene dimaleimide, triallylisocyanurate, trimethylolpropane trimethacrylate, tetraallyloxyethane, triallyl cyanurate, tetramethylene diacrylate, polyethylene glycol dimethacrylate, and mixtures thereof.
8. A flame retardant composition of claim 1, wherein the at least one thermoplastic polyester continuous phase comprises a copolyetherester elastomer prepared from monomers comprising (1) poly(tetramethylene oxide) glycol; (2) a dicarboxylic acid selected from the group consisting of isophthalic acid, terephthalic acid and mixtures thereof; and (3) a diol selected from the group consisting of 1,4-butanediol, 1,3-propanediol and mixtures thereof.
9. A flame retardant composition of claim 1, wherein the flame composition comprises at least one amorphous polymer.
10. A flame retardant composition according to claim 9, wherein the at least one amorphous polymer is selected from the group consisting of polycarbonates, polyarylates, amorphous polyester copolymers, polymethylmethacrylate, and mixtures thereof.
11. A flame retardant composition of claim 1, wherein the flame retardant composition comprises one or more additives selected from the group consisting of heat stabilizers, antioxidants, metal deactivators, and mixtures of two or more thereof.
12. A wire or cable comprising a coating comprising the flame retardant composition recited in claim 1.