A combination structure for a base member and an erect member, and a manufacturing method thereof, are disclosed. The combination structure includes a base member comprising a slot and a through hole in communications with the slot. An erect member is inserted into the slot, and a combining member detachably engages with the through hole. The combining member thereby fixedly positions the erect member in the slot when the combining member is joined to the through hole.

A retaining clip includes a first strap body and a second strap body. The first strap body includes a first engaging portion. The first engaging portion includes a first abutting surface and a first protrusion. One end of the second strap body is connected with one end of the first strap body. The second strap body includes a ring-shaped portion and a second engaging portion. The second engaging portion is adapted to be detachably engaged with the first engaging portion and includes a second protrusion and a second abutting surface. When the first engaging portion is engaged with the second engaging portion, the first strap body passes through the ring-shaped portion, and the first abutting surface faces the second abutting surface, and the first protrusion faces the second protrusion.

A writing instrument that includes an elongated body with a first end and a second end, wherein the first end is coupled to a post and the second end has an aperture for a writing tip to be exposed, a rotary bearing coupled to the post, wherein the rotary bearing has a central opening and wherein the post at least partially extends through the central opening of the rotary bearing, and a rotary device coupled to the bearing.

[Problems] An object of the present invention is to provide: a thermochromic color-memory composition which effectively expresses a property of being able to interchangeably memorize and retain colors and which is thus applicable to various fields; and a thermochromic color-memory microcapsule pigment encapsulating the same. [Solution] Provided is a thermochromic color-memory composition including: (a) an electron-donating color-developing organic compound; (b) an electron-accepting compound; and (c) an ester compound represented by the following Formula (1), as a reaction medium which controls color reaction between the component (a) and the component (b): ##STR00001##
(wherein, R represents an alkyl group having 3 to 18 carbon atoms, a cycloalkylalkyl group having 6 to 11 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms or an alkenyl group having 3 to 18 carbon atoms; each X independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 3 carbon atoms or a halogen atom; and each Y independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group or a halogen atom).

A housing element for a writing instrument includes a hollow, sleeve-shaped, elongated base body having an opening for receiving the writing instrument or a pencil lead of the writing instrument at a first longitudinal end. The base body has a second longitudinal end, which is opposite the first longitudinal end, and has a retaining recess that is formed with a polygonal cross section for directly or indirectly retaining a bit in a rotationally fixed manner. A writing instrument including the housing element is also provided.

The present invention provides for a writing instrument that includes an elongated body with a first end and a second end, wherein the first end is coupled to a post and the second end has an aperture for a writing tip to be exposed, a rotary bearing coupled to the post, wherein the rotary bearing has a central opening and wherein the post at least partially extends through the central opening of the rotary bearing, and a rotary device coupled to the bearing.

[Problems] An object of the present invention is to provide: a thermochromic color-memory composition which effectively expresses a property of being able to interchangeably memorize and retain colors and which is thus applicable to various fields;

and a thermochromic color-memory microcapsule pigment encapsulating the same.

[Solution] Provided is a thermochromic color-memory composition including: (a) an electron-donating color-developing organic compound; (b) an electron-accepting compound; and (c) an ester compound represented by the following Formula (1), as a reaction medium which controls color reaction between the component (a) and the component (b):

##STR00001##

(wherein, R represents an alkyl group having 3 to 18 carbon atoms, a cycloalkylalkyl group having 6 to 11 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms or an alkenyl group having 3 to 18 carbon atoms; each X independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 3 carbon atoms or a halogen atom; and each Y independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group or a halogen atom).

A writing instrument includes an elongated body with a first end and a second end, wherein the first end is coupled to a post and the second end has an aperture for a writing tip to be exposed, a rotary bearing coupled to the post, wherein the rotary bearing has a central opening and wherein the post at least partially extends through the central opening of the rotary bearing, and a rotary device coupled to the bearing.

A mechanical pencil includes a main body in which a mechanism for discharging a pencil lead is located, and a clip attached to the main body wherein the clip includes a container for storing a refill for a pencil lead.

A pencil holder for storing a pencil includes a hollow basic body which has an elongated interior that opens out in an insertion opening for partially receiving the pencil. In the region of the insertion opening the basic body merges into a least one retaining tongue which juts out from the basic body in the longitudinal direction and which is set up for the purpose of holding the pencil on the basic body as a result of clamping.