WO2000013897A1 - Laminate, method for the production and use thereof - Google Patents

Abstract

Disclosed is a laminate with a flexible decorative layer (4) in addition to at least one layer of plastic-resin impregnated supporting material e.g. a layer of resin-laminated core paper, whereby at least one outer thermoactivatable adhesive layer (3) is applied to the at least one plastic-resin impregnated supporting material. The invention also relates to a method for producing the inventive laminate, whereby heat and pressure are applied and the layers (3, 4, 6) are pressed in one step. According to the invention, the laminate can be used as a flexible layer on a platen for a composite platen. The inventive laminate is especially suitable for use on a pressure-sensitive platen.

Description

"Laminate, process for its production and its use"

The invention relates to a laminate, a method for its production according to the preamble of claim 1 or claim 7 and its use.

State of the art

Laminates in the form of an HPL (High Pressure Laminate) or a CPL (Continuous Pressure Laminate) are used, for example, together with a particle board as a carrier board for the production of a composite board.

An HPL or CPL laminate regularly consists of a melamine-formaldehyde resin-impregnated decorative film and one or more core papers that are phenol-formaldehyde resin-impregnated or other resin-absorbing carrier media. HPL materials are manufactured in single or multi-day presses with or without a cooling cycle using pressure and a suitable temperature. CPL materials are manufactured in continuous presses (CPL systems) using pressure and a suitable temperature. Before the When applied to a carrier plate to produce the composite plate, the back of the pressed layer material is usually ground in order to obtain a surface that is as flat and adhesive-affine as possible for the subsequent bonding step with the carrier plate. Bonding to the carrier board is generally carried out under pressure and using a suitable adhesive system (e.g. wood glue). However, the gluing process has the disadvantage that in some cases (for example when gluing with wood glue) a not completely uniform glue application can be achieved before gluing (gluing), that is to say that in some places the glue is present in small quantities or even completely (which preferably occurs in the edge zones of the board materials) or, in contrast, the adhesive (glue) forms lumps or is soaked up by the (open-pore) carrier material so that the adhesive is no longer available on the surface in sufficient quantity for bonding. When gluing with conventional adhesive systems, the problem of temporary adhesive activity (e.g. open time) must also be taken into account, whereby a certain time must not be exceeded between the time the adhesive system is applied and the components to be bonded are brought together not to fall below a desired minimum liability of the components to one another. Furthermore, only a material can be used as the carrier plate for the composite plate, which withstands the pressure during gluing without damage.

A disadvantage of the use of the adhesive systems described above is also the emission of volatile constituents and solvents from the liquid adhesive system and the associated impact on people and the environment, as well as the problem of cleaning the containers, pipes and machines from adhesive residues and disposal this adhesive residue or Cleaning solutions and the associated pollution of the environment.

Object and advantages of the invention

The invention has for its object to provide a layered material which is particularly suitable for producing a composite panel and does not overcome the aforementioned disadvantages.

This object is achieved by a laminate according to claim 1. The invention further relates to processes for producing this laminate and to the use thereof.

The invention relates to a layered fabric with a flexible decorative layer and at least one synthetic resin-impregnated substrate layer, e.g. B. from a resin-impregnated core paper layer. The core idea behind the laminate is that an externally located thermo-activatable adhesive layer is applied to the at least one resin-impregnated carrier material layer, which does not show any adhesive properties at room temperature. As a result of this measure, the laminate can be laminated onto a surface with comparatively substantially lower pressing pressures only by suitable heating to a predetermined temperature. A thermally activated hot-melt adhesive film is preferably used. For example, the thermal lamination of the laminate in a direct coating recooling press can also be carried out by other suitable methods on a desired carrier medium, e.g. B. a chipboard to produce a composite panel on one or both sides. In order to increase the throughput in such a composite panel production, in particular in comparison to a cold glue cold press, a multi-day direct coating recooling press can also be used become. The laminate according to the invention eliminates problems such as adhesive layer inhomogeneities in the form of reduced or missing adhesive application, accumulations of adhesives or adhesives sagging into the carrier medium when producing composite panels in comparison with conventional adhesive bonding techniques (e.g. cold gluing). In contrast to this, the thermo-activatable adhesive layer is present in a closed and uniform thickness on the laminate, preferably in foil form, which also contributes to a quieter surface appearance when arranged on a composite panel. Furthermore, due to the avoidance of faulty glue points, higher process reliability is achieved and the yield z. B. improved in the production of composite panels. Another advantage is that when using the thermolaminatable laminate, the use of a sanding unit to produce an adhesive-affine laminate rear side and the use of units for storing, metering and applying the adhesive can be dispensed with.

The thermally activated laminate also does not require a protective film on the adhesive side during storage and / or during transport. Its adhesive activity is only caused at a predetermined temperature. It is also possible to provide a large number of different adhesive films for different temperature ranges on the basis of nonpolar and polar plastics for different laminates. The final thickness of the laminate can also be adjusted via the number of core paper layers used or other resin-absorbing carrier material layers.

In a particularly advantageous embodiment of the laminate, there is a absorbent layer between the at least one synthetic resin impregnated carrier material layer and the thermally activated adhesive layer, preferably a sodium kraft paper. This absorbent layer liner enables the combination z. B. a phenol formaldehyde resin-impregnated core paper (thermoset) with a polyolefin adhesive layer (thermoplastic), which could otherwise show connection problems if necessary. In particular, due to the structure of the laminate with an intermediate layer of absorbent paper and the thermoplastic and elastic adhesive layer on the back, the latter has greater flexibility than a conventional laminate. The increased flexibility of the laminate according to the invention facilitates handling and transportation. The adhesive layer reduces the risk of breakage and reduces the possibility of material fragmentation. This not only reduces material losses, it also prevents the risk of injury from splinters or sharp edges. Due to the increased flexibility of the laminate and its reduced tendency to break, laminates can be produced on single or multi-day presses with a cooling cycle or on CPL or short-cycle systems with suitable devices for cooling the thermally activated laminate as well as for further processing and use safe to handle, the thickness of which is less than 0.5 mm.

It is particularly preferred to use a plurality of core paper layers with a specific weight of approximately 70-400 g / m ² , preferably 150-160 g / m ² . It is also advantageous to use absorbent paper in the form of a sodium kraft paper with a weight of approx. 30-250 g / m ² , preferably 80 g / m ² . In addition, it is preferred if the hot-melt adhesive layer has a specific weight of approximately 20-150 g / m ² , preferably approximately 45 g / m ² .

In a preferred method for producing the laminate according to the invention, the layers are one or several resin-absorbing layers of material, e.g. B. synthetic resin impregnated core paper layers, optionally a layer of absorbent paper and the adhesive layer in one step under pressure and heat. As a result, the synthetic resin z. B. in the core paper and the adhesive layer "liquid". As the layer build-up cools, a begins

Recrystallization process of the adhesive film, in which the connection with the underlying layer takes place. It is important for the later bonding process that the adhesive layer can be heated several times for bonding, provided that a critical temperature is not exceeded. In order to be able to remove the layer structure from the press in a simple manner, it is further proposed that a separating layer, for. B. a Teflon film is arranged.

For easy handling of the individual layers for producing the laminate according to the invention, it is also proposed that a thermally activated adhesive film is first connected to an impregnated or non-impregnated paper layer and then the layers are placed one above the other and pressed together with an external adhesive film.

It is particularly preferred if the temperature during the pressing process is selected such that the synthetic resin in the synthetic resin-impregnated carrier material layer and the thermally activated adhesive layer melt without the above-mentioned temperature with regard to the adhesive layer being exceeded. This would reduce or even lose the adhesive properties of the adhesive layer. The thermo-activatable adhesive layer also has the advantage that when a composite panel produced from the laminate according to the invention and a carrier board is specifically reheated, the components are recycled into the material in the sense of recycling Output products can be separated and reused or reused for specific components.

The pressing process can advantageously be carried out in a single- or multi-day high-pressure recooling press, preferably in a multi-day high-pressure press with a chill cycle.

Alternatively, the pressing process can also be carried out in a continuous, so-called CPL pressing system with sufficient cooling capacity for cooling the thermally activated laminate.

The pressing process can also be carried out using the short-cycle method in connection with a suitable device for cooling the thermally activated laminate outside the pressing process.

For an effective pressing process, two identical layer sequences in a mirrored arrangement between z. B. Process two structuring or smooth structure donors (e.g. press plates) at the same time. In order to avoid that the opposite adhesive layers bind together, a non-adhesive release medium, e.g. B. inserted a bilateral separating film or plate. The separating medium, which in another embodiment can also be arranged between the structure donor (for example press plate, press tape) and the adhesive layer, can be easily and completely removed after production. In a preferred embodiment of the invention, the separation medium can be reused for further manufacturing processes.

The laminate according to the invention can particularly preferably be used as a flexible layer on a carrier plate of a composite plate. However, the particular advantage of the laminate according to the invention is that the application (lamination) - as already mentioned above - can be carried out with comparatively low pressures. This means that even those supports can be provided with a thermoactivatable laminate that compresses in an undesired manner, if necessary deformed and partially destroyed and thus reduced in thickness, in a conventional standard press for carrying out a bonding step (e.g. cold gluing) would. This means that almost all pressure-sensitive carrier materials can be used as a carrier plate for gluing with the laminate according to the invention. For example, a honeycomb panel, a foam lath, a lightweight panel or the like may be mentioned as the carrier plate. By combining these pressure-sensitive materials with the thermo-laminatable laminate according to the invention, a large number of novel composite materials can thus be produced.

The carrier materials that can be glued with the thermolaminable laminate can be selected from a wide range of materials. Examples include wood, metal, plastic, glass, ceramic, textile and other inorganic bwz. Called organic materials.

It is also possible to fix the thermo-laminatable laminate solely by targeted, contactless heating - for example by infrared radiation or by supplying hot air - and thereby melting the adhesive layer onto almost any backing plate without the effect of high pressure and temperature on the backing or on the top of the thermolaminatable laminate, the carrier is damaged or the decorative surface of the laminate is impaired in its degree of gloss and / or its decorative structure. The use of the thermo-laminatable laminate is by no means restricted to planar carrier materials. So z. B. the laminate due to its already mentioned increased flexibility and reduced tendency to break also advantageous on non-planar substrates, such as. B. apply pipes, columns and other round shaped bodies.

The use of the laminate is also not limited to solid supports with regard to its bondability. Thus, in a particular form of use, the thermolaminatable laminate can also be brought into contact with liquid, heated plastic materials in such a way that a flat composite slat or another shaped composite element is formed after the plastic has cooled.

Composite elements of this type cannot be produced with conventional laminates.

The product technology data of a

Laminated chipboard composite panels are in any case comparable to a conventionally produced composite panel. Some parameters, such as B. peel strength, d. H. the adhesion of the laminate to the chipboard even clearly exceeds the values of a conventional laminate-chipboard composite. The heat resistance of a composite system according to the invention can be adjusted via the selection of the adhesive layer.

Finally, the laminate according to the invention in the Do It Yourself (DIY) and hobby area by the user himself and individually z. B. be applied by means of an iron or other suitable device to a wood base material or the like. Drawings

An embodiment of the invention is shown in the drawing and explained in more detail with the mention of further advantages and details.

The figure shows

a sectional view of two mirror-symmetrically arranged layer sequences of a laminate during the pressing process between two press plates.

Description of the embodiment

In the figure, a section of two mirror-symmetrically arranged laminates 1 between two press plates 2 are shown in cross-section during a pressing process. Each laminate 1 consists of a thermally activated hot-melt film 3, a subsequent, for. B. 80 g / m ² heavy sodium kraft paper 4, several phenol formaldehyde resin-impregnated core papers 5 and finally a z. B. Melamine formaldehyde resin-impregnated decorative film 6. So that the superimposed during the pressing process

Do not glue hot-melt film layers 3 to one another, there is a separating layer 7 between them.

During the pressing process, the resin melts in the decorative film 6, in the core paper 5, and the hot-melt film. This connects the decorative film with the core paper and the core paper on one side with the sodium kraft paper. On the other hand, the hot-melt film forms an intimate connection with the sodium kraft paper. The temperature is reduced during the pressing process even under pressure, which causes the melted layers to solidify. After removing the Press plates 2 and the reusable separating layer 7 have two thermo-activatable layer materials available after one operation, which can be combined with a large number of carrier materials by reheating, which results in the hot-melt film melting.

Reference symbol list:

1 laminate

2 press plates

3 hot-melt film

4 sodium kraft paper

5 core paper

6 decorative film

7 release film

Claims

Expectations : 1. laminate with a flexible decorative layer and at least one resin-impregnated carrier material layer, for. B. a resin-impregnated core paper layer, characterized in that on the at least one Carrier material layer (5) an external thermo-activatable adhesive layer (3) is applied. 2. Laminate according to claim 1, characterized in that the adhesive layer is a thermally activated hot-melt film. 3. Laminate according to claim 1, characterized in that a absorbent layer (4) is arranged between the at least one carrier material layer (5) and the thermally activated adhesive layer (3). 4. Laminate according to one of the preceding claims, characterized in that one or more core paper layers (5) have a specific weight of about 70 - 400 g / m ² . 5. Laminate according to one of the preceding claims, characterized in that the absorbent layer (4) comprises a sodium kraft paper or a parchment paper or another suitable absorbent special paper with a specific weight of approx. 30-250 g / m ² . 6. layered fabric according to one of the preceding claims, characterized in that the thermally activated adhesive layer (3) has a specific weight of about 20 - 150 g / m ² . 7. A method for producing a laminate according to one of claims 1 to 6, characterized in that the layers are pressed in one step under pressure and heat. 8. The method according to claim 6, characterized in that before the pressing on the outer adhesive layer, a separating layer, for. B. Teflon film is arranged. 9. The method in particular according to claim 6 or 7, characterized in that first a thermo-activatable adhesive film is connected to an impregnated or non-impregnated paper layer and then the layers with the external adhesive film are superimposed and pressed. 10. The method according to any one of claims 7 to 9, characterized in that the temperature during the pressing process is selected so that the synthetic resin in the synthetic resin-impregnated substrate material layer (5) and the thermally activated adhesive layer (3) melt. 11. The method according to any one of claims 7 to 10, characterized in that the pressing process takes place in a single or multi-day high-pressure recooling press, preferably a multi-day high-pressure press with a chill cycle. 12. The method according to any one of claims 7 to 10, characterized in that the pressing process takes place in a CPL (Continuous Pressure Laminate) pressing device. 13. The method according to any one of claims 7 to 10, characterized in that the pressing process in one Short cycle press in connection with a cooling of the Laminate is carried out by a suitable cooling device outside the press. 14. Use of the laminate according to one of claims 1 to 6 as a flexible layer on a carrier plate of a composite plate. 15. Use of the laminate according to one of claims 1 to 6 as a flexible layer on a carrier plate of a composite plate, the carrier plate made of a pressure-sensitive material, such as. B. a honeycomb panel, a foam panel, a lightweight panel or the like.