Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
  • D21H27/18—Paper- or board-based structures for surface covering
  • D21H27/22—Structures being applied on the surface by special manufacturing processes, e.g. in presses
  • D21H27/26—Structures being applied on the surface by special manufacturing processes, e.g. in presses characterised by the overlay sheet or the top layers of the structures
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/54—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen
  • D21H17/57—Polyureas; Polyurethanes

Definitions

• the present invention relates to a base paper for decorative coating materials, in particular laminated materials, laminates, decorative films and pre-impregnates produced by the short-cycle method.
• the most important material basis for the production of decorative films or decorative laminates are special base papers that are impregnated with synthetic resin as so-called decorative papers.
• the decorative coating materials are preferably used for surface coating in furniture manufacture and in interior construction.
• Decorative film is understood to be a resin-impregnated or resin-impregnated and surface-treated paper web, which is glued to a carrier plate under the action of heat and / or pressure.
• Laminates High Pressure Laminates are laminates that are created by pressing several impregnated, stacked papers.
• the structure of these laminates generally consists of a transparent support sheet (overlay) that produces maximum surface resistance, a resin-impregnated decorative paper and phenol-coated kraft paper. Hardwood and chipboard as well as plywood are used as a base for this.
• the decorative paper impregnated with synthetic resin is pressed directly onto a base (e.g. chipboard) using low pressures.
• the decorative paper used in the coating materials mentioned above is used in white or color with or without additional printing.
• the process step of impregnating or impregnating the decorative paper which is essential for the production of the coating materials, requires resins which can easily penetrate into the capillary spaces of the paper and harden there.
• Thermosetting resins such as urea-formaldehyde resin and melamine-formaldehyde resin or thermoplastic resins such as polyester resins are used for this purpose.
• the known coating materials are in need of improvement from an ecological point of view. According to the current international status, a large number of the known decorative film types and laminates do not yet meet the requirements for formaldehyde emissions of less than 0.1 ppm. In connection with the global efforts to minimize environmental pollution, the production of environmentally friendly coating materials is therefore becoming increasingly important.
• the present invention is therefore based on the object of providing a base paper for decorative coating materials, in particular for laminated materials, laminates, decorative films and pre-impregnates produced by the short-cycle method, which continues to meet the requirements placed on the base paper and those mentioned at the outset and which are more environmentally friendly to produce decorative composite systems.
• a base paper which consists of cellulose fibers, at least one filler and a wet-strengthening cationic resin and which is treated with a polyisocyanate and / or a modified polyisocyanate.
• the polyisocyanate and the modified polyisocyanate have cycloaliphatic and / or aliphatic isocyanate groups (CNO).
• CNO cycloaliphatic and / or aliphatic isocyanate groups
• the isocyanate groups can also be aromatically bound.
• the modified polyisocyanate can be a polyether-modified or a polyester-modified polyisocyanate.
• the polyisocyanate and / or modified polyisocyanate is water dispersible. Mixtures of polyisocyanates which are not self-dispersible with ionic or nonionic emulsifiers can be used as water-dispersible polyisocyanates.
• self-dispersing polyisocyanates are used in water.
• the polyisocyanate and / or the modified polyisocyanate can be nonionic or cationic.
• the cationicity can be brought about by the content of tertiary amino or ammonium groups.
• the amount of the polyisocyanate and / or modified polyisocyanate used for treating the base paper according to the invention is preferably 0.5 to 40% by weight, based on the paper pulp.
• the polyisocyanates used according to the invention can be used both for impregnating the paper web and in bulk.
• Suitable fillers for the base papers according to the invention are, for example, titanium dioxide, zinc sulfide, calcium carbonate, kaolin, talc or mixtures thereof.
• a rutile titanium dioxide surface-treated with Al2O3 is used.
• the amount of titanium dioxide in the paper pulp is between 1 and 55% by weight.
• Melamine-formaldehyde resins, polyamine or polyamide derivatives can be used as wet strength agents in amounts of 0.2 to 2% by weight.
• the paper pulp can also contain other substances such as organic and inorganic colored pigments and dyes, optical brighteners, retention aids and dispersing agents.
• the base papers according to the invention are produced in a known manner using a paper machine in a grammage range from 50 to 200 g / m 2, the products to be used according to the invention preferably being applied in the paper machine using a size press. However, they can also be applied to the surface of the base paper to be coated using all other known application units.
• Example 2 A base paper as in Example 1 was treated with the following 15% aqueous dispersion and dried: Dispersion Weight gain,% V1a V1b V1c V1d Epichlorohydrin resin (Nadavin DHN) 2.0 6.1 11.3 16.0
• the base paper from Example 1 without surface treatment was used as a comparison.
• test strips 15 x 100 mm were dipped in melamine resin MW 550 (without wetting agent and without hardener), placed over a flat surface between two strips of blotting paper, loaded with a support weight for 15 s and then weighed back. The resin absorption is calculated in% of the sample weight.
• test strips (8 x 6 cm) were immersed in a 98% triethanolamine solution (TEA) stained with rhodamine B.
• TEA triethanolamine solution
• Penetration is measured from the time the paper is placed in the solution until the first drops of liquid appear on the surface.
• a paper strip of defined length and width (1.5 x 10) was clamped in a holder and brought into contact with water or air of certain humidity. The resulting stretch or shrinkage is transferred to a recorder. The transverse elongation (%) was calculated on the basis of the measurement curve, taking strip length into account.
• the opacity is a measure of the translucency of the paper. It was measured on 8 x 8 cm paper test strips using the Elrepho 2000 colorimeter.
• the stiffness values of the base papers were determined with the bending stiffness tester from Lorentzen & Wettre, according to standard SCAN-P 29.69. The measured values are given in mN.
• test strips 15 mm wide were immersed in distilled water for a period of 5 minutes.
• the wet strips were then tested for their wet breaking load in a tensile testing machine.
• the measured values are given in mN. The lower the numerical value, the worse the wet strength.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Paper (AREA)

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Citations (4)

• 1994
  • 1994-12-14 DE DE19944444489 patent/DE4444489A1/de not_active Withdrawn
• 1995
  • 1995-12-04 EP EP95119031A patent/EP0717145A1/fr not_active Withdrawn

Patent Citations (4)

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