A coated paperboard comprising a paperboard substrate having a first side and a second side and a coating in contact with the first side of the paperboard substrate, the coating including binder and pigment, the coating containing substantially no fluorochemical or wax, wherein the coated paperboard has a 3M kit test value of at least 3, and wherein the coated paperboard is repulpable.

A method for preparing a printable substrate having a showthrough value of about 0.14 or less, and an opacity value of at least about 88% which includes a paper substrate with a first and second surfaces formed of paper fibers having a basis weight of from about 12 to about 32 lbs/1300 ft.sup.2, and a substrate filler in an amount in the range of from 0 to about 30% by weight of the paper substrate; and a surface size layer on at least one of the first and second surfaces, the surface size layer having about 50 lbs or less per ton of the paper substrate of a starch surface sizing agent and a multivalent metal salt drying agent in an amount sufficient to impart to the at least one of the first and second surfaces a black print density value of at least about 0.8 when inkjet printed with pigmented inks and a waterfastness value of at least about 85% when inkjet printed with dye-based inks, the printable substrate having a MD tensile strength of at least about 12 lbs/in. and a CD tensile strength of at least about 6 lbs/in.

A method for preparing a printable substrate having a showthrough value of about 0.14 or less, and an opacity value of at least about 88% which includes a paper substrate with a first and second surfaces formed of paper fibers having a basis weight of from about 12 to about 32 lbs/1300 ft.sup.2, and a substrate filler in an amount in the range of from 0 to about 30% by weight of the paper substrate; and a surface size layer on at least one of the first and second surfaces, the surface size layer having about 50 lbs or less per ton of the paper substrate of a starch surface sizing agent and a multivalent metal salt drying agent in an amount sufficient to impart to the at least one of the first and second surfaces a black print density value of at least about 0.8 when inkjet printed with pigmented inks and a waterfastness value of at least about 85% when inkjet printed with dye-based inks, the printable substrate having a MD tensile strength of at least about 12 lbs/in. and a CD tensile strength of at least about 6 lbs/in.

A surface treatment composition for paper, board or other fibrous webs. The composition of the invention comprises particles which comprise an active material and a supporting material. The active material comprises a salt of a multivalent metal, such as a divalent or trivalent metal. In accordance with the invention, the supporting material is adapted to release the active material from the particles when subjected to heat and/or pressure and/or a change in pH. Consequently, the active material's adverse effects on the rheology of the composition are avoided while its desired effects on the surface characteristics are retained or enhanced.

A water-dispersible composite structure, which comprises one or more layers, and a method of producing the same. At least a part of the layers is formed by a fibrous web or sheet containing 50-90 parts by weight of wood fibers and 10-90 parts by weight of annual or perennial plant fibers and/or 10-50 parts by weight of synthetic short-cut fibers, and 0.1-20% by weight of a binder, calculated from the weight of the fibers, and at least a part of the binder being a water-soluble polymer and another part a water dispersible binder, and the fibrous sheet or web being produced by wet forming. By means of the invention, the fibers of the composite structure can be recovered and recycled by equipment conventionally used in the paper and paperboard industry.

A water-dispersible composite structure, which comprises one or more layers, and a method of producing the same. At least a part of the layers is formed by a fibrous web or sheet containing 50-90 parts by weight of wood fibers and 10-90 parts by weight of annual or perennial plant fibers and/or 10-50 parts by weight of synthetic short-cut fibers, and 0.1-20% by weight of a binder, calculated from the weight of the fibers, and at least a part of the binder being a water-soluble polymer and another part a water dispersible binder, and the fibrous sheet or web being produced by wet forming. By means of the invention, the fibers of the composite structure can be recovered and recycled by equipment conventionally used in the paper and paperboard industry.

The present invention relates to a press-heating gas grafting hydrophobization apparatus, and a hot water-resistant paper and an oil-absorbing paper manufactured using the press-heating gas grafting hydrophobization apparatus. In the press-heating gas grafting hydrophobization apparatus according to the present invention, since a non-air-permeable dryer belt is provided surrounding and pressing a drying roller to prevent dissipation from a base material of a fatty acid chloride vaporized by the drying roller, the press-heating gas grafting hydrophobization apparatus has an advantage of improving efficiency of a gas grafting reaction. Therefore, by using the press-heating gas grafting hydrophobization apparatus according to the present invention, the reaction amount of fatty acid chloride per unit area can be remarkably improved.

The present invention relates to a press-heating gas grafting hydrophobization apparatus, and a hot water-resistant paper and an oil-absorbing paper manufactured using the press-heating gas grafting hydrophobization apparatus. In the press-heating gas grafting hydrophobization apparatus according to the present invention, since a non-air-permeable dryer belt is provided surrounding and pressing a drying roller to prevent dissipation from a base material of a fatty acid chloride vaporized by the drying roller, the press-heating gas grafting hydrophobization apparatus has an advantage of improving efficiency of a gas grafting reaction. Therefore, by using the press-heating gas grafting hydrophobization apparatus according to the present invention, the reaction amount of fatty acid chloride per unit area can be remarkably improved.

Methods and apparatuses for roll coating are provided. The roll coating system (100) includes a coating roll (110) having a deformable inner layer (12) with a surface thereof covered by a deformable outer layer (14), the inner layer being softer than the outer layer. A substrate (3) is conveyed to the nip (12) between the coating roll and a back-up roll (120). A metered coating material is transferred from the coating roll to a patterned surface structure (40) of the substrate at the nip to form a conformal coating on the patterned structure of the substrate.

A sheet for thermal printing is provided, which may include: a first layer including: a sheet material dyed in a specific color; and a second layer coextensive with the first layer and including a plurality of particles randomly and evenly arranged per a thickness unit and per an area unit of the second layer, the particles being at least partly transmissive to light in the visible light range.