There is a compound represented by the following formula (I):

##STR00001##

in which R1 and R2, identical or different, represent a C.sub.2-C.sub.30 alkyl group, a C.sub.2-C.sub.30 alkenyl group, a C.sub.2-C.sub.30 alkynyl group, or a C.sub.2-C.sub.30 alkoxy group, the alkyl, alkenyl, alkynyl, or alkoxy groups being optionally substituted with at least one hydroxy, halogen, amino, C.sub.1-C.sub.8 alkyl, or C.sub.1-C.sub.8 alkoxy group, as a temperature change regulating agent in a thermochromic ink composition. There also are thermochromic pigment microcapsules having a compound of formula (I) according to the disclosure, to ink compositions having such thermochromic pigment microcapsules, and to writing instruments comprising such ink compositions.

In a pencil lead manufactured through a baking step regardless of being a black lead or a colored lead, the mechanical strength of the pencil lead is further increased by coating a surface thereof with a resin. A pencil lead includes a baked lead body whose surface is covered by a covering layer made of resin that has a scratch hardness of HB or greater. The scratch hardness of the resin as a subject resin is defined as a lowest hardness index of a tester pencil that is able to form an indentation on a surface of a horizontal flat plate coated with a 5-μm thick film of the subject resin, when the surface is scratched by the tester pencil being pressed onto the surface at an angle of 45° with a load of 7.355 N.

In a pencil lead manufactured through a baking step regardless of being a black lead or a colored lead, the mechanical strength of the pencil lead is further increased by coating a surface thereof with a resin. A pencil lead includes a baked lead body whose surface is covered by a covering layer made of resin that has a scratch hardness of HB or greater. The scratch hardness of the resin as a subject resin is defined as a lowest hardness index of a tester pencil that is able to form an indentation on a surface of a horizontal flat plate coated with a 5-μm thick film of the subject resin, when the surface is scratched by the tester pencil being pressed onto the surface at an angle of 45° with a load of 7.355 N.

A novel blending stump pencil device that provides a user with one implement for both drawing and blending. The device comprises a wood-bodied pencil with a blending stump attached to a rear of the pencil via a securing apparatus. The device comprises a clear finish and a removable plastic sleeve that protects the blending stump from damage and debris. Further, the device can be included in a kit with multiple pencil types.

A novel blending stump pencil device that provides a user with one implement for both drawing and blending. The device comprises a wood-bodied pencil with a blending stump attached to a rear of the pencil via a securing apparatus. The device comprises a clear finish and a removable plastic sleeve that protects the blending stump from damage and debris. Further, the device can be included in a kit with multiple pencil types.

There is a lead casing for pencil for writing, drawing, marking, plotting, and/or coloring, made of a composition having, by weight relative to the total weight of the lead casing for pencil: a) from 50 to 95% of a mixture of polylactic acid and bio-polyethylene in a weight ratio polylactic acid/bio-polyethylene ranging from 60/40 to 90/10, and b) from 5 to 40% of vegetable fillers chosen in the group consisting of wood fibers. There is a pencil including the lead casing for the pencil of the disclosure for writing, drawing, marking, plotting, and/or coloring as well as a method for manufacturing such a pencil.

There is a lead casing for pencil for writing, drawing, marking, plotting, and/or coloring, made of a composition having, by weight relative to the total weight of the lead casing for pencil: a) from 50 to 95% of a mixture of polylactic acid and bio-polyethylene in a weight ratio polylactic acid/bio-polyethylene ranging from 60/40 to 90/10, and b) from 5 to 40% of vegetable fillers chosen in the group consisting of wood fibers. There is a pencil including the lead casing for the pencil of the disclosure for writing, drawing, marking, plotting, and/or coloring as well as a method for manufacturing such a pencil.

There is a compound represented by the following formula (I): ##STR00001##
in which R1 and R2, identical or different, represent a C.sub.2-C.sub.30 alkyl group, a C.sub.2-C.sub.30 alkenyl group, a C.sub.2-C.sub.30 alkynyl group, or a C.sub.2-C.sub.30 alkoxy group, the alkyl, alkenyl, alkynyl, or alkoxy groups being optionally substituted with at least one hydroxy, halogen, amino, C.sub.1-C.sub.8 alkyl, or C.sub.1-C.sub.8 alkoxy group, as a temperature change regulating agent in a thermochromic ink composition. There also are thermochromic pigment microcapsules having a compound of formula (I) according to the disclosure, to ink compositions having such thermochromic pigment microcapsules, and to writing instruments comprising such ink compositions.

The present invention relates to a polymer-based extendable lead or refill for writing, drawing and/or painting tools comprising a binder comprising a mixture of polylactide with at least one polymer having a flexural modulus inferior to the flexural modulus of polylactide and at least one filler. It also relates to writing, drawing and/or painting tool, advantageously a pencil, comprising lead or a refill according to the invention and to the use of a binder comprising a mixture of polylactide with at least one polymer having a flexural modulus inferior to the flexural modulus of polylactide according to the invention to improve the vividness of polymer-based extrudable lead or refill for writing, drawing and/or painting tools.

The present invention relates to a polymer-based extendable lead or refill for writing, drawing and/or painting tools comprising a binder comprising a mixture of polylactide with at least one polymer having a flexural modulus inferior to the flexural modulus of polylactide and at least one filler. It also relates to writing, drawing and/or painting tool, advantageously a pencil, comprising lead or a refill according to the invention and to the use of a binder comprising a mixture of polylactide with at least one polymer having a flexural modulus inferior to the flexural modulus of polylactide according to the invention to improve the vividness of polymer-based extrudable lead or refill for writing, drawing and/or painting tools.