A polymer-bound refill for writing, drawing and/or painting devices, in particular for pencils or coloured pencils, including at least one binder, at least one wax, at least one colouring agent and at least one filler. The refill includes polylactide as binder.

A polymer-bound refill for writing, drawing and/or painting devices, in particular for pencils or coloured pencils, including at least one binder, at least one wax, at least one colouring agent and at least one filler. The refill includes polylactide as binder.

A pencil lead and a pencil containing the pencil lead wherein the pencil lead is polymer-based, extrudable, non-expanded, non-calcined and comprises graphite, of which 25% to 100% by weight or 50% to 100% by weight of the graphite, in relation to the total weight of the graphite, is expanded graphite.

A pencil lead and a pencil containing the pencil lead wherein the pencil lead is polymer-based, extrudable, non-expanded, non-calcined and comprises graphite, of which 25% to 100% by weight or 50% to 100% by weight of the graphite, in relation to the total weight of the graphite, is expanded graphite.

The invention relates to a graphite lead or graphite chalk or graphite block for drawing and painting, having a base body made of a base mass at least containing a cellulose-based binding agent, a filler, and graphite, the base body being impregnated with a waterproof preparation mixture containing at least a mixture of iso-paraffins and n-paraffins or a water-soluble preparation mixture containing at least a water-soluble emulsifier.

The invention also relates to a pencil with such a graphite lead and to a method for producing a graphite lead or graphite chalk or a graphite block.

The invention relates to a graphite lead or graphite chalk or graphite block for drawing and painting, having a base body made of a base mass at least containing a cellulose-based binding agent, a filler, and graphite, the base body being impregnated with a waterproof preparation mixture containing at least a mixture of iso-paraffins and n-paraffins or a water-soluble preparation mixture containing at least a water-soluble emulsifier.

The invention also relates to a pencil with such a graphite lead and to a method for producing a graphite lead or graphite chalk or a graphite block.

A pencil lead may achieve high levels of both improved density and improved fixability of a hand-drawn line and also be less likely to stain a hand during writing. Examples of this pencil lead include a pencil lead comprising a black porous fired lead body including at least graphite, wherein at least a compound selected from octyldodecyl erucate, oleyl oleate, octyldodecyl oleate, isopropyl palmitate, 2-ethylhexyl palmitate, and propylene glycol monooleate is impregnated in pores of the porous fired lead body. The pores of the black porous fired lead body are preferably impregnated with at least one selected from a terpene phenolic resin, a rosin ester resin, a ketone resin, and a rosin-modified phenolic resin, in addition to the compound.

A pencil lead may achieve high levels of both improved density and improved fixability of a hand-drawn line and also be less likely to stain a hand during writing. Examples of this pencil lead include a pencil lead comprising a black porous fired lead body including at least graphite, wherein at least a compound selected from octyldodecyl erucate, oleyl oleate, octyldodecyl oleate, isopropyl palmitate, 2-ethylhexyl palmitate, and propylene glycol monooleate is impregnated in pores of the porous fired lead body. The pores of the black porous fired lead body are preferably impregnated with at least one selected from a terpene phenolic resin, a rosin ester resin, a ketone resin, and a rosin-modified phenolic resin, in addition to the compound.

This disclosure describes a process for preparing silica-coated calcium carbonate particles, involving the steps of preparing an aqueous carbonate slurry containing calcium carbonate particles, adding at least one silicate composition to the aqueous carbonate slurry to obtain a carbonate-silicate slurry, lowering a pH of the carbonate-silicate slurry by adding at least one acidic compound to obtain a pH-adjusted slurry containing the silica-coated calcium carbonate particles, and isolating the silica-coated calcium carbonate particles—in which at the adding of the acidic compound is controlled such that a final pH of the pH-adjusted slurry ranges from about 7 to about 10, and the silica-coated calcium carbonate particles include a porous coating having an average pore diameter ranging from 2 nm to 50 nm. This disclosure also describes articles and compositions containing the silica-coated calcium carbonate particles, as well as hollow silica spheres formed from the silica-coated calcium carbonate particles.

This disclosure describes a process for preparing silica-coated calcium carbonate particles, involving the steps of preparing an aqueous carbonate slurry containing calcium carbonate particles, adding at least one silicate composition to the aqueous carbonate slurry to obtain a carbonate-silicate slurry, lowering a pH of the carbonate-silicate slurry by adding at least one acidic compound to obtain a pH-adjusted slurry containing the silica-coated calcium carbonate particles, and isolating the silica-coated calcium carbonate particles—in which at the adding of the acidic compound is controlled such that a final pH of the pH-adjusted slurry ranges from about 7 to about 10, and the silica-coated calcium carbonate particles include a porous coating having an average pore diameter ranging from 2 nm to 50 nm. This disclosure also describes articles and compositions containing the silica-coated calcium carbonate particles, as well as hollow silica spheres formed from the silica-coated calcium carbonate particles.