CS276670B6 - Surface-treated paper and cartons and methods for making the same - Google Patents

Abstract

Papers and cardboards with a surface treatment are provided with a film-like coating on a fibrous structure from a polystyrene solution. The amount of polystyrene, depending on the final use, is 0.5 to 5% by weight. The production principle is based on impregnation with a polystyrene solution and subsequent drying in a suspension. In order to achieve the required properties for use in printing or packaging technology, it is necessary to adjust the concentration of the impregnation bath to 5 to 15% by weight and to dry at temperatures in the range of 110 to 170 °C.

Description

Field of technology.

The present invention relates to papers and cartons coated with polymer solutions.

Prior art

Papers and cardboards for demanding prints are chemically treated in various ways already during production on a paper machine to increase the wet strength. Another possibility is the treatment of papers and cardboards by painting with special mixtures of polymers and fillers for the field of printing or certain types. with application in the food industry as a packaging material.

However, this does not solve other demands associated with the application of these materials, such as the requirement of high wet strength while at the same time high flexural strength or high surface strength, or high internal bond strength. In the case of the production of cartographic maps, a solution using fibrids and polymers is possible, and the use of polyamides is known. This method requires considerable demands on the production / process and ecology.

The increase in wet strength is solved by a number of manufacturing companies in the paper industry on the principle of using urea or melamine formaldehyde resin. Information on these compositions is published by a number of companies: BASF products are known or applications are disclosed in U.S. Patents 4,537 G57 and 4,336,835. Use of a resin made by polymerizing epichlorohydrin aliphatic dicarboxylic acid and polyalkylamine. Glyoxal polyalkylamide base with a cationic regulator according to U.S. Pat. No. 4,333,411 is also used. By these means, the wet strength is achieved up to a maximum value of -20% of the dry strength. Depending on the management of the technological process, there are losses of chemicals in wastewater. Other principles are based on the application of glyoxal by spraying according to patents ČSSR 208 53G. She is known! The method uses butadiene styrene latex, which is subsequently vulcanized with resorcinol formaldehyde / resin according to patent 249 7G0 of the Czechoslovak Socialist Republic. The main problem is the achievement of uniformity of application in the area of paper or cardboard and environmental issues, because the resins used contain free formaldehyde. Another way of treating papers and cartons with polymers is extrusion with linear polymers, capolymers of vinyl chlorides or vinylidene chlorides according to Czechoslovakia. copyright certificate No. 2032 G5 with application for packaging purposes. . . . - \; ..

A significant group of chemical agents that are applied to paper outside the machine are polymers based on silicones of solvent or disperse types. According to MS. copyright certificate No. 181 453 is used. A special chemical system for reinforcing silicone resins. The result is highly water-resistant, highly hydrophobic and anti-adhesive papers. TAPPI magazine, 1987 (No. Gstr. 103), describes a curing process for a silicone polymer using an elevated temperature catalyst. Silicon papers and cartons treated in this way are difficult to print and their use is primarily for technical and packaging applications. ' OF'- /-.-/ ..

However, the above procedures do not guarantee the achievement of all the required properties of those which, in addition to physical parameters, meet the requirements of polygraphic and print properties. . ''.

The use of polystyrene from a solution of aromatic solvents is a solution that provides the necessary properties of a new type of map paper with high surface strength, hydrophobicity, dimensional stability, but at the same time good printability with high color resolution. The application of polystyrene is the principle below: in this case, the new solution. . . ... , 'o

CS 27GG70 B6

SUMMARY OF THE INVENTION 7 '.' '/.,. '7

The essence of the invention lies in the fact that the paper or cardboard is treated with polystyrene, which forms a film on the fibers of the natural polymer in an amount of 0.5 to 5% by weight, into a fibrous part. This film is a guarantee of quality for high-quality prints, the polymer is formed on paper or cardboard by impregnation on an oil from a solution of polystyrene in toluene and other aromatic solvents. After penetration of the solution, suspension drying is carried out at an initial temperature of 110 ° C up to a maximum temperature of 170 ° C at the end of drying. - · .. -.-: -. . . '.' <· '. '‘

A characteristic of the novelty is the use of the property of polystyrene applied from a toluene solution in combination with paper or paperboard based on pulp. A 6-fold increase in the surface strength of the paper is achieved, a two-fold increase in the bending strength of the papers and cartons, an increase in the mechanical wet resistance. Paper or cardboard can be labeled with common writing means and is very easy to remove, marking by erasing without damaging the surface. ¹ ''

Examples of embodiments of the invention

Attach 1. ... - - - -. ’

Paper intended for the production of geodetic and other maps is impregnated or coated with a solution of 5 wt.%, Polystyrene. · -. 95% by weight of toluene. -.

After application of the solution occurs between k.penetraci baniSinovými fibers, followed by drying at a belt speed of the paper in the oven 6 to 15 m. .Min '· ³ in a drying tunnel. The weight gain reaches 0.6 to 1.1 Ϊ wt. From the point of view of further use of paper, the optimal increase is 1.0% by weight. · -.- <. i.

Example ^2/7, 7 · .- ^<; - '' 7 '' 7: <

Paper intended for packaging · is impregnated with a solution of:

· ... · 10% by weight of polystyrene. <<90% by weight, toluene, or benzene, or xylene

The paper is dried to penetrate. The temperature regime is maintained so that polymer migration does not occur. This means that the final drying temperature must not exceed 170 ° C at fast. z. '' -i- ^: .. ··· · '. ··' - ' ¹ paper belt length 15 m.min. ·.?

Papers and cartons coated with a polystyrene-based polymer are made by saturating the paper or paperboard in a pulp with a solution of polystyrene in a toluene solution. The amount of application is. ř £ Sí; concentration of polystyrene solutions, moving speed of paper or cardboard: vefoulard and.speed in the application system in the impregnation machine. Saturated paper; or carton with a solution of polystyrene is then air-dried in a hot-air oven. ..

Industrial applicability ... · .. ·

-.- About 5 in • the paper industry 'is used to · improve the quality of pulp mills ·

CS 27G57C 36 boxes and cartons. On impregnation devices which are equipped with lift drying, the drying is trouble-free. When guiding the drying curve ... from -110> ° C to i70 ° C at the end: drying and at the optimum speed of the paper or cardboard belt. 10 raeru. Another use of treated paper or cardboard is in the printing industry. It uses better properties for prints, which are then used in the production of geodetic manus, which are used in natural terrain, including humid environments; The descriptiveness of maps by divine writing instruments and the easy removal of "labels without damage" predetermine such products for wide use. The second area _: is the application and packaging, so that it combines the treated paper or cardboard with high demands on flexural strength and weather resistance. . , '' ^: Λ

Claims (2)

PATEN TO V í '. CLAIMS ^7: ' 1. Papers and cardboards coated with a polymer solution, characterized in that they consist of fibrous structures of natural polymer with a basis weight of 70 to -2 „„ - '. . -. '. .::. _v '- _ 250 g λ 'treated with a film of polystyrene in an amount of 0.5 to 5% by weight, per fibrous part. -. ’’ '' 2. A process for the production of paper and board according to claim 1, characterized in that the paper or board web is impregnated with a solution of polystyrene in aromatic solvents such as toluene, xylene, benzene, followed by drying the solvent in suspension at 110 ° C to 170 ° C. 'Ϊ' ’. ’’. and '-L:' ... '.