DE1771507A1 - Process for the production of laminates of great hardness and flexibility - Google Patents

Description

PATENT LAWYERS

DR. CLAUS REINLÄNDER DIPL-ING. KLAUS BERNHARDT Qg pj _D

Since MUNICH 23
MAINZER STRASSE 5

CENTRAL ADAMAS S.p.A. Milan / Italy

Process for the production of laminates of great hardness and flexibility

Priority: June 3, 1967 Italy file number: 16 843 A / 67

For the production of laminates are present various methods known; these are essentially based on the use of paper made from pure cellulose, which is impregnated with synthetic resin - generally with phenolic resin - and then several of which are placed on top of one another Sheets are pressed at high temperature. Different thicknesses are used in such plastic composites by laying a larger or smaller number on top of one another Obtained clay impregnated bow

«. 2 «· 109887/1509

Purely these are now generally used procedures basically two different types of paper are used, namely *

1. Kraft pulp paper, weight or similar. 150 gr / sqm, impregnated with solutions or dispersions of synthetic, preferably phenolic resins, then dried and is cut into formats. Several such sheets of paper are used to form the inner one The finished laminate is placed on top of one another.

2. Paper made of "alpha cellulose", possibly with wood imitation decoration o.a., is impregnated with synthetic resins, preferably melamine resins. Such sheets of paper are used for the outer layers of the finished laminate used.

Eventually, but not necessarily, also will a very thin paper, weight approx. 20 - 30 gr / qm, used, also impregnated with synthetic resin applied to the upper surface of the laminate to make the surface more solid and shiny.

- 3 109887/1509

A layer of stacked sheets of paper from the above mentioned type is pressed for a few tens of minutes between bare and chrome-plated plates, with one Pressure tone approx. 70 kg / qm and a temperature tone approx. 150 - 170 ° C. Before pressing material removed from the press the plates are cooled to prevent the formation of moisture bubbles or even the detachment of the various Avoid shifts

With this method, laminates with favorable properties, such as high hardness and good abrasion resistance, are obtained, but the method is rather expensive due to the inevitable handling of the numerous paper layers in successive operations of impregnation and drying. In addition, the Schichtpresstoff obtained is little flexible and very brittle% these features make a "factory in thicknesses of less than 0.6 mm impossible.

The invention is therefore intended to be an economical Process for the production of a rubber compound with overall better mechanical properties are made available. This object is achieved according to the invention solved that a synthetic resin or a resin mixture was added directly to a cellulose material for paper

109887/1509 " ⁴ "

is that from this material sheets or plates of any thickness in a cardboard machine ^ and the so produced sheets or plates can be treated directly in a varm press. It turned out to be surprising found that it is possible to use a bow . or to obtain a plate in a single, homogeneous layer that can be treated directly in the hot press, if that is normally the case with the known method The amount of resin required for impregnating the papers is at least partially added directly to the cellulose material becomes, and that then a Sohiohtpresetoff with large Flexibility can be achieved.

You can manufacture such sheets or plates on one known machine for cardboard in rolls or sheets follow, starting at Hindestdioken τοη approx. 0.3 mm, to too thick τοη oa. 3 am. The received Sohiohtpresetoff retains the same excellent properties of hardness and abrasion resistance, along with a good one Flexibility.

Preferably the method of the present invention is used carried out as follows

A fabric made of unbleached, semi-bleached or

109887/1509 - 5 -

bleached Kraft cellulose, as needed, becomes a Dispersion of phenolic resins added, in percent by weight, which is at least part of that amount of resin which is used for the known method for impregnating the paper. These resins are preferably whipped onto the elementary fibers of the pulp, with the addition of a coagulant and / or a fixing agent such as sodium chloride, Aluminum sulfate or similar

The fabric prepared in this way is fed into a cardboard machine, e.g. a combined machine for the production of relatively thin strips of material - from 0.3 to 1 mm - or in a hand-held cardboard machine with a format roller for production of sheets of greater thickness from 1 to 3 mm.

The sheet or plate produced in this way has sufficient consistency to be easily transported and directly into the To be brought to a press for polymerization and hardening of the resins provided temperature; the press will get the finished product in the way you want Dioke removed

The sheet or plate produced on the cardboard machine can still undergo double treatments before

109887/1509 ~ ⁶ ~

he got under the press. In particular, it can be immersed in a melamine resin bath to take part in the Surface to receive a resin coating, which gives the finished sheet better abrasion resistance. Besides it is possible to apply a decoration to the surface of the sheet, by varnishing or a two-color trioh directly on the sheet itself, or by applying a very thin sheet that has been colored beforehand has been printed.

ffaeh the method of the present invention is accordingly a Sohiohtpresstoff achieved, which has unexpected, excellent mechanical properties absolutely lower cost. The possibility of achieving much smaller thicknesses appears particularly interesting - up to 0.3 mm - thanks to the great flexibility and low brittleness of the material obtained; here results a saving in material and consequently also in Production and storage costs without sacrificing abrasion resistance would worsen. The application to the carrier material by gluing, e.g. on wood, is due to the good adaptability of the very thin laminate to the shape of the carrier material facilitated · The manufacturing process is more economical and works quickly, since there is practically no time for the impregnation the one bow and the preparation of those to be laid on top of each other Sheet pacts in discontinuation comes

109887/1509

Claims (8)

06 P1 D claims s 1.) Process for the production of layered materials from of great hardness and flexibility, characterized in that a cellulose material for paper is a synthetic Resin or a resin mixture is added directly so that sheets or plates are then produced from this material in the desired bead on a cardboard machine and the sheets or plates produced in this way are treated directly under a hot press 2. The method according to claim 1, characterized in that the amount of synthetic resin added to the paper stock is at least part of the total required Amount of resin is. 3. The method according to claim 1 or 2, characterized in that that the synthetic resins are added in the form of a solution or dispersion and then precipitated, before the sheets or plates are formed. 4 «Method according to claim 1, 2 or 3» characterized in that that the ones from the cardboard machine 109887/1509 -A2- stepping arches or plates a covering of eyntetlschem Resin is applied before eie under the Hot press are brought. 5. The method according to claim 4 »characterized in that that the coating is applied by spraying 6. The method according to claim 4, characterized in that that the coating is applied in the immersion process. 7. The method according to any one of claims 1-6, characterized in that that phenolic resins are added as resin. 8. The method according to any one of claims 4, 5 or 6, characterized characterized in that the resin coating consists of thermal amine resin. 109887/1509