DE2424471A1 - METHOD OF MANUFACTURING A FILM WITH SURFACE TREATMENT AND THE USE OF IT - Google Patents

Description

Dr. Hans-Heinridi Willrath. ■ _n . ·

T ^ r ^. , "J /. ""^aui;:-;;. D-62 WIESBADEN May 17th 1974

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r. Dieter Vi ^ ber: * »hAw

Dipl. ~ Phys. KIa ^ s Seiffert SKSS? · " ^{II / wh}

PATENTANWÄLTE telegram address - WILLPATENT 1

Billingsfors Bruks Aktiebolag, Billingsfors, Sweden

Process for producing a film with surface treatment and their use

Priority; Patent application

No. 73-07145-8 of May 21, 1973 in

Sweden

The present invention relates to a method for producing a film which, in terms of appearance, has at least one their surfaces through impregnation and surface treatment is post-treated on the surface, and this film is made for application to substrates such as. Particles are thought of composite boards, flat boards, panels and the like. The invention also relates to films obtained by this process.

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With a view to streamlining efforts in the furniture industry there is a great need for prefabricated surfaces, i.e. on surfaces that do not require painting. This need has hitherto largely been met in such a way that printed and unprinted papers impregnated with melamine were used, for example on the one composed of particles Board, such as a wood fiber board, or the furniture part can be pressed on under increased temperature and pressure. From some point of view these surfaces have suitable properties, but they can from the aesthetic point of view cannot be compared with a surface painted in the usual way.

Attempts have been made to impregnate such melamine with a subsequent coating using Combine color components to give the surface a painted look and properties. However, this method did not give satisfactory results because, in simple terms, it was to be impregnated Paper must have large pores in order to facilitate the impregnation and, in contrast, the subsequent coating thick paper is required to get good results.

It has now been shown, surprisingly, that the problem of producing a satisfactory product by combining an impregnation

to get,
tion and overlay / can be solved in the following manner

When carrying out the impregnation in a paper making machine before final drying, it is possible to create a tight pa-

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pier with a sufficient resin content, which is suitable for subsequent coating. The addition of the resin can be done in different ways depending on the requirement to the end product and after the technical facility, and the resin solids content can also be in the corresponding Degree varies within as broad limits as 5 to 60% by weight based on the weight of the paper and resin will. A particularly preferred range for resin solids is 15 to 40% by weight, calculated on the same basis.

According to the method of the invention, the impregnated base sheet has a Gurley porosity of at least 12 sec / 100 ml. The base film is finally on the surface coated by applying a mixture of pigment and binder and optionally also adding a colorant. The impregnating agent used is preferably an aqueous resin solution or dispersion.

The reason that this method is advantageous seems to be the fact that the cellulose fibers are in a known per se Are subject to irreversible changes during drying in the papermaking machine. To the subsequent To enable impregnation, it is normally necessary in the manufacture of the paper to keep the paper very open make, i.e. the fibers must not be beaten too strongly, whereby the paper containing a pore system does the impregnation relieved. However, this openness remains even after the impregnation and means difficulties for the subsequent

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de coating. It is desirable to keep the applied coating paste on the surface, but this creates openness or porosity of the paper that it penetrates.

If, however, according to the invention, the impregnation with a Impregnating agents, such as urea or melamine resin types, for example, are used in papermaking the final drying takes place, either by adding to the stock material or in the paper making machine Spraying, in a dressing press or the bath, or a combination thereof, can avoid the above dilemma. As long as the paper is not completely dry, it retains its porous structure and can easily be used even at higher levels Impregnate degrees of impact and thus results in a denser paper after the final drying. In this case, the paper can also use a machine-glazed surface in order to further improve the result of the subsequent coating.

The subsequent surface coating can be carried out in a manner known per se Way. If an aqueous dispersion is used, application in air is with a brush or a brush Squeegees are preferred, while if the composition contains solvents or other volatile components, an overcoat with a roller or in a so-called curtain machine led to the best results.

In principle, any type of thermoplastic or thermosetting plastic can be used in the method according to the invention compatible with or dispersible in water. As particularly suitable resins, the aminoplasts can be

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are mentioned, such as urea or melamine resins. It is also possible to use thermosetting plastics of the type Use phenolic, acrylic, epoxy, polyurethane and polyester plastics.

The mixture of pigment and binder used for the final coat may have widely varying compositions in accordance with conventional art. So can as a pigment titanium dioxide, clay or chalk can be used. The binder in the coating mixture can, for example, consist of Acrylic latex, styrene-butadiene latex, melamine resin or urea resin or from a UV-curing or catalyst-curing polyester or a binder from nitrocellulose or acid-hardening type. The coating mixture can also contain a colorant if so desired.

The cellulose-based fiber material that forms the base film, can be from any source of cellulose, such as mechanically prepared pulp, chemically prepared pulp and semi-chemically prepared paper stock. Chemically prepared paper stock including sulphite pulp and sulphate pulp, can be used in bleached, semi-bleached or unbleached form, with bleached pulps being preferred and especially bleached sulphate pulp is cheap.

In the following, the invention is illustrated by examples which illustrate the concept of the invention not limit, further explained. In these examples the porosity is given according to Gurley, and this The porosity value is determined according to the standard method SCAN-P 19:66. Although all examples use bleached

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Concerning sulfate cellulose, it should be noted that in the formation the base film all types of cellulose-based fiber materials are useful, such as those given above, and the invention is in no way limited limited the use of bleached sulfate cellulose only.

example 1

2
A paper of about 60 g / m 2 of bleached sulfate cellulose was produced with the simultaneous addition of about 10% by weight of urea resin (based on the dry paper weight) to the stock material and about 20% by weight by spraying onto the paper strip after the press section. The urea resin added to the stock material was a resin called Dynorit ^ L 32O (der Dyno Industrier, Norway) and the urea resin which was applied to the paper sheet by spraying was Kaurit 210 (BASF, West Germany), together with O, O2 % By weight NH * C1 as a catalyst. The impregnated paper then had a surface weight of about 80 g / m 2 and a Gurley porosity of 80 sec./100 ml. In

In a subsequent process, the paper was 40 g / m a pigmented polyester varnish coated with a peroxide catalyst had been added. The film obtained was then used to cover furniture parts by resin glue applied to a board made of particles, then applied the film and pressed it in a press with

2
a pressure of 10 kp / cm and for 15 seconds at about 140 ° C. The product obtained had a

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hard, smooth surface that can be used as an exterior surface in shelves and Closets was suitable.

Example 2

2
A paper made of about 100 g / m 2 of bleached sulfate cellulose was in the middle of the drying section of a papermaking

machine in an introduced bath impregnated with 40 g / m melamine resin, and this impregnation was given a machine-glazed finish. The melamine resin used was Kauramin ^ '772 (an aqueous solution of a condensation product von- urea and formaldehyde from BASF, West Germany) together with 0.025% by weight HCOOH as a catalyst. After Upon final drying, the paper had a surface weight of

140 g / m. The porosity was 35 sec / 100 ml Paper in two stages with one pigmented with titanium dioxide

Melamine solution coated. The amount applied was 25 g / m 2.

As in Example 1, the film was pressed onto a board of particles with wet adhesive. The latter was then used to to cover the inside of kitchen equipment.

Example 3

2
A paper made from about 120 g / m 2 of bleached sulfate cellulose was made

with 40 g / m 2 of a urea resin in the middle of the drying section a papermaking machine in an imported make-ready press. The urea resin used here was Kaurit ^ 210 (a liquid condensation resin of Melamine and formaldehyde from BASF, West Germany).

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A dried one removed downstream of the dressing press Sample showed a porosity of 50 sec./100 ml. After further drying, the paper was in a doctor blade coating device, which was introduced into the papermaking machine with

20 g / m of a coating paste, in which the pigment consists of 50% titanium dioxide and 50% clay and the binder consists of an in Acrylate latex dispersed in water. After final drying, the finished film was produced in a manner similar to that in Example 1 used to cover the interior of simple wardrobes and cloakrooms.

Similar results were obtained when using unbleached sulfate pulp to make the base sheet and when using used bleached or unbleached sulphite pulp.

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Claims (9)

Patent claims .j Process for the production of a film with surface aftertreatment, characterized / that a sheet-like fiber material based on cellulose in a paper making machine impregnated with an impregnating agent before final drying, while giving the sheet a Gurley porosity of at least 12 sec / 100 ml and then the sheet on at least one of its surfaces with a mixture of pigment and binder coated. 2. The method according to claim 1, characterized in that the impregnating agent in an amount of 5 to 60% by weight, before-ί preferably used in an amount of 15 to 40% by weight, based on the solids weight of the impregnated base film. 3. The method according to claim 1 and 2, characterized in that in the surface treatment on at least one A colorant is applied to the surface of the sheet. 4. The method according to claim 1 to 3, characterized in that an aqueous resin solution or dispersion is used as the impregnating agent used. 5. The method according to claim 1 to 4, characterized in that the impregnating agent is an aminoplast, such as a urea or melamine resin is used. 6. The method according to claim 1 to 4, characterized in that a thermosetting salt of the phenolic is used as the impregnating agent Type, acrylic resin type, epoxy resin type, polyurethane resin type 409850/0835 . 242U71 or polyester type or a mixture of one or more of these substances is used. 7. The method according to claim 3 to 6, characterized in that the surface using one of titanium dioxide, clay or chalk coated with existing pigment. 8. The method according to claim 1 to 7, characterized in that the surface by applying a pigment and a Binder made from a dispersion of acrylic latex, styrene-butadiene latex, Melamine resin or urea resin consists or these contains, coated. 9. The method according to claim 1 to 7, characterized in that the surface by applying a mixture of pigment and a binder consisting of a UV-curable or catalyst-curing polyester or a binder of the nitrocellulose or acid-curing type or contains such, covers. A09850 / 0836