Polymerizable compositions comprising a radically polymerizable resin can be polymerized in the absence of a peroxide initiator and other undesirable components. The polymerizable compositions and methods employ a manganese- or iron-containing salt or organic complex and a 1,3-dioxo compound with one or more other components. The polymerizable compositions have better storage stability and reduced gel time-drift.

Polymerizable compositions comprising a radically polymerizable resin can be polymerized in the absence of a peroxide initiator and other undesirable components. The polymerizable compositions and methods employ a manganese- or iron-containing salt or organic complex and a 1,3-dioxo compound with one or more other components. The polymerizable compositions have better storage stability and reduced gel time-drift.

A description is given for an anti-drumming composition comprising a polymer dispersion comprising at least one dispersed (meth)acrylic polymer obtainable by emulsion polymerization of radically polymerizable (meth)acrylic monomers, a high density filler mixture and a specific dispersing aid, wherein the anti-drumming composition has either a volume contraction or only a very low volume expansion after drying.

A description is given for an anti-drumming composition comprising a polymer dispersion comprising at least one dispersed (meth)acrylic polymer obtainable by emulsion polymerization of radically polymerizable (meth)acrylic monomers, a high density filler mixture and a specific dispersing aid, wherein the anti-drumming composition has either a volume contraction or only a very low volume expansion after drying.

Polymerizable compositions comprising a radically polymerizable resin can be polymerized in the absence of a peroxide initiator and other undesirable components. The polymerizable compositions and methods employ a manganese- or iron-containing salt or organic complex and a 1,3-dioxo compound with one or more other components. The polymerizable compositions have better storage stability and reduced gel time-drift.

Provided is an acrylic polymer composition comprising an acrylic polymer and a polyfunctional organic compound having a urea group, wherein the acrylic polymer composition has less than 50% decrease in molecular weight of the acrylic polymer when heated under conditions of 190 C. and 144 hours in air.

Provided is an acrylic polymer composition comprising an acrylic polymer and a polyfunctional organic compound having a urea group, wherein the acrylic polymer composition has less than 50% decrease in molecular weight of the acrylic polymer when heated under conditions of 190 C. and 144 hours in air.

Provided is an acrylic polymer composition comprising an acrylic polymer and a polyfunctional organic compound represented by the following general formula (1):

##STR00001## (in the general formula (1), R.sup.4 and R.sup.2 are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R.sup.3 and R.sup.4 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms; and k is an integer of 1 or larger).

Provided is an acrylic polymer composition comprising an acrylic polymer and a polyfunctional organic compound represented by the following general formula (1):

##STR00001## (in the general formula (1), R.sup.4 and R.sup.2 are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R.sup.3 and R.sup.4 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms; and k is an integer of 1 or larger).

An electrophotographic photoreceptor includes a conductive substrate, a charge generation layer provided on the conductive substrate, a charge transport layer provided on the charge generation layer, and a surface protective layer provided on the charge transport layer, in which the surface protective layer is a cured film formed of a composition that contains a resin (X) having at least one of a unit represented by Formula (X1) or a unit represented by Formula (X2) and a reactive group-containing charge transport material containing a reactive group and a charge-transporting skeleton in an identical molecule.

##STR00001##