The present disclosure is drawn to sizing compositions, which can include 25 wt % to 80 wt % starch based on dry components, 15 wt % to 60 wt % cationic multivalent salt based on dry components, and an organic additive. The organic additive can be a water-swellable polymer having a weight average molecular weight ranging from 150,000 Mw to 1,000,000 Mw, a wax, or both the water-swellable polymer and the wax.

The present invention provides a preparation method of aramid fiber far-infrared emitting paper. In the present invention, para-aramid chopped fiber and para-aramid pulp fiber are used as paper base functional materials with excellent characteristics of high specific strength and high specific stiffness. In addition, the para-aramid chopped fiber and the para-aramid pulp fiber can form a paper material with pores and porous channels, and carbon nanotubes are embedded into the structural pores and porous channels of the paper material. Therefore, the aramid fiber far-infrared emitting paper has better molding quality and composite performance. Results of embodiments indicate that: A far-infrared wavelength emitted by the aramid fiber far-infrared emitting paper provided in the present invention is 4 μm to 20 μm, a main frequency band thereof is approximately 10 μm, and far-infrared conversion efficiency is up to 99%; and the aramid fiber far-infrared emitting paper has tensile strength of 0.12 KN/mm.sup.2 to 0.18 KN/mm.sup.2, and can be bent and folded.

The present invention provides a preparation method of aramid fiber far-infrared emitting paper. In the present invention, para-aramid chopped fiber and para-aramid pulp fiber are used as paper base functional materials with excellent characteristics of high specific strength and high specific stiffness. In addition, the para-aramid chopped fiber and the para-aramid pulp fiber can form a paper material with pores and porous channels, and carbon nanotubes are embedded into the structural pores and porous channels of the paper material. Therefore, the aramid fiber far-infrared emitting paper has better molding quality and composite performance. Results of embodiments indicate that: A far-infrared wavelength emitted by the aramid fiber far-infrared emitting paper provided in the present invention is 4 μm to 20 μm, a main frequency band thereof is approximately 10 μm, and far-infrared conversion efficiency is up to 99%; and the aramid fiber far-infrared emitting paper has tensile strength of 0.12 KN/mm.sup.2 to 0.18 KN/mm.sup.2, and can be bent and folded.

The present invention relates to a coating composition for coating of paper or paperboard, said composition comprising: a pigment, a binder, an optical brightening agent (OBA), and xylitol, and to paper or paperboard coated with at least one layer of the coating composition. The present invention further relates to a method for preparing said coating composition and to an OBA premix useful in the method of preparing the coating composition, said premix comprising an OBA and xylitol, wherein the OBA and sugar alcohol together make up at least 10% by weight, preferably at least 20% by weight, based on the total weight of solids in the premix.

The present invention relates to a coating composition for coating of paper or paperboard, said composition comprising: a pigment, a binder, an optical brightening agent (OBA), and xylitol, and to paper or paperboard coated with at least one layer of the coating composition. The present invention further relates to a method for preparing said coating composition and to an OBA premix useful in the method of preparing the coating composition, said premix comprising an OBA and xylitol, wherein the OBA and sugar alcohol together make up at least 10% by weight, preferably at least 20% by weight, based on the total weight of solids in the premix.

The invention relates to a security pigment, comprising core-shell particles having a core based on an organic addition polymer, a shell based on an organic condensation polymer and a feature substance present in the core in finely dispersed or dissolved form, wherein the addition polymer is a three-dimensionally cross-linked duromer.

The invention relates to a security pigment, comprising core-shell particles having a core based on an organic addition polymer, a shell based on an organic condensation polymer and a feature substance present in the core in finely dispersed or dissolved form, wherein the addition polymer is a three-dimensionally cross-linked duromer.

Provided herein are polysaccharide derivatives substituted (a) at a degree of substitution (DS1) of at least 0.05 by a fluorescent group (FG) having a mono or polycyclic ring system including at least one heteroatom selected from N, O and S and conjugated double bonds, and having an absorption band in the UV region of light and an emission band in the visible region of light, and bonded via a first linker to any one of the native functional groups of the polysaccharide repeating units; and (b) at a degree of substitution (DS2) of at least 0.05 by a charged group (CG) bonded via a second linker to any one of the native functional groups of the polysaccharide repeating units.

Provided herein are polysaccharide derivatives substituted (a) at a degree of substitution (DS1) of at least 0.05 by a fluorescent group (FG) having a mono or polycyclic ring system including at least one heteroatom selected from N, O and S and conjugated double bonds, and having an absorption band in the UV region of light and an emission band in the visible region of light, and bonded via a first linker to any one of the native functional groups of the polysaccharide repeating units; and (b) at a degree of substitution (DS2) of at least 0.05 by a charged group (CG) bonded via a second linker to any one of the native functional groups of the polysaccharide repeating units.

Provided herein is a colorant composition comprising: 1) water; 2) at least one water-soluble inorganic salt; 3) microcrystalline cellulose; and 4) at least one colorant comprising water-soluble anionic dyes, water-soluble fluorescent brighteners, water-soluble cationic dyes, or combinations thereof. The colorant composition described may have a weight ratio of the at least one water-soluble inorganic salt to the at least one colorant in the colorant composition ranges from 1:0.25 to 1:4.0 and a specific gravity of the colorant composition is about 1.05 kg/l to about 1.45 kg/l. Also provided are methods of preparing the disclosed colorant composition.