国家/地区 中国（4）
IPC部 C（4）
IPC大类 C09（4）
IPC小类 C09D（4）
IPC C09D013/00（4）
发明人 WANG H（3） YUAN D（2）
公开年 2018（4）
申请年 2017（4） 
专利权人 GUANGAN CITY.（4）

High strength pencil core comprises sodium thiosulfate, sodium humate, graphene, talc, food grade paraffin wax, sodium carboxymethyl cellulose and clove oil.

YUAN D, WANG H

Environmentally friendly dustless chalk comprises desulfurated ash, sodium thiosulfate, activated clay, titanium pigment, pigment, nano graphene, paraffin, lecithin and water.

WANG H, LUO A

Nontoxic dustless chalk comprises gypsum powder, magnesium carbonate, titanium pigment, activated clay, medical stone powder, plant pigment, nano graphene, borax, Aloe and water.

DUAN J, YUAN D

Dustless chalk comprises calcined gypsum powder, talc powder, pigment, nano graphene, carboxymethyl cellulose, polysorbate, and water.

WANG H, DAI B