DE102018006613A1 - Material, in particular for the production of window elements - Google Patents

Abstract

The present invention provides a material comprising at least one layer of wood and a layer of imitation wood, the layer of imitation wood comprising PVC resin and rice or peanut shell powder.

Description

The present invention relates to a material, particularly suitable for the production of window elements, the production of this material and its use and the elements obtained thereby.

Windows and doors are often made from wood materials. Due to the availability and sustainability of this material and the good possibilities for processing and shaping (sawing, milling, etc.), woods are popular materials in the manufacture of such elements. Although the material often still works after processing, which may require maintenance work on corresponding elements, such as windows or doors, as well as their frames and frames, etc., such disadvantages are often caused by the aesthetics of the corresponding elements and the aspects of the end user which have positive connotations Use of wood weighed. At the same time, however, there are disadvantages, in particular the susceptibility of wood to weather when it is exposed to external weather in windows and doors. Since often protective coatings cannot completely overcome this disadvantage, there are sometimes quite complex approaches, for example the attachment of metal, often aluminum profiles on the outside, in order to enable better protection. Plastic windows are another option for providing weatherproof windows and doors.

The present invention therefore aims to provide a material which retains the advantages of using wood and at the same time overcomes the disadvantages of using wood, in particular weather resistance.

This object is achieved by the material according to claim 1. Preferred configurations are specified in the subclaims and the description below.

Furthermore, the present invention provides a method for producing the material, as well as its use for producing elements such as window frames, door frames, doors and frames, etc., which have a side that is exposed to the weather.

The material according to the invention is a composite, with at least one layer of wood and thus positively connected, for example by gluing, a layer made of an imitation wood, comprising PVC resin and rice or nutshell powder. Elements such as window scantlings, etc., which have a surface made of wood and a surface made of imitation wood, can be produced from such a material by conventional methods such as sawing and milling. This can later be aligned in the end application so that it faces outwards, since the imitation wood has a much higher weather resistance than wood. However, the imitation wood according to the invention can be processed just like woodworking, that is to say sanding, painting, glazing, etc., so that despite the use of an imitation wood on the outside, a look and feel corresponding to a wood is obtained. At the same time, a wooden surface is provided on the inside, as was previously the case with wooden windows.

The wood to be used in the context of the invention can be any wood, in particular those which are conventionally used for the production of window and door elements. Examples are both European coniferous and European hardwoods and non-European woods, such as Douglas fir, pine, fir, spruce, larch, oak, beech, maple, balau, azobe, birch, alder, ash, aspen, linden, church, plane, robinia , Teak, elm, etc. In the material according to the invention there can be one or more layers of wood which are firmly connected to one another. The presence of several layers of wood, possibly with a selected relative arrangement of the fiber orientations, can be advantageous with regard to later use.

With this at least one layer of wood, a layer of imitation wood is firmly and positively connected. This can be achieved by gluing with conventional wood glue used in wood processing.

The imitation wood to be used according to the invention is based on a thermoplastic polar resin mixed with a cellulose-containing component. In contrast to wood substitute materials, which are based on non-polar thermoplastic materials such as polyethylene, the use of a polar component enables the production of a layer that actually has a very wood-like appearance and feel. A preferred polar thermoplastic resin is PVC. Suitable cellulose-containing components are used in the form of finely ground powders, usually with particle sizes in the range from about 20 to 200, preferably 30 to 100, particularly preferably 40 to 60. Suitable materials are rice and nutshell powder, straw, wood, etc., are preferred rice husk powder. A particularly suitable composition for the imitation wood preferably comprises PVC resin in a mixture with rice or peanut shell powder, preferably rice shell powder. Such imitation wood compositions are for example in the EP 2 536 785 A whose disclosure content is included here by reference. The ratio of PVC resin to rice or peanut shell powder can vary over a wide range. The composition of the imitation wood can be about also have other components, such as fillers, additional polymers, etc. The imitation wood is usually produced as a plate, foamed or not foamed, and then bonded to the at least one wood layer. The imitation wood particularly preferably contains a mixture of 20 to 60% by weight, preferably 30 to 40% by weight of PVC resin (PVC = polyvinyl chloride) and 20 to 60% by weight, preferably 30 to 40% by weight of powder from rice husks or husks and / or peanut husks or husks. Its particle size is preferably 0.42-0.25 mm (40-60 mesh). The designation "mesh" denotes the mesh size of sieves and thus serves as a measure for specifying particle or grain sizes. The smaller the mesh value, the larger the particle size of the bulk material to be described. There are tables for converting mesh values into mesh sizes in mm, for example from the US Bureau of Standards.

The PVC material used is not subject to any particular restrictions. In particular, PVC recycling material can also be used. For example, a PVC resin suspension with a K value of 60-70 is suitable. The K value is a number that is calculated from measurements of the viscosity of dilute solutions of a polymer and a measure of the degree of polymerization or the molecular size is. The K value is used for resin specification.

The rice bowls or peanut shells used are also not subject to any particular restrictions, especially not with regard to certain types of rice or peanuts. Rice bowls give better results and are therefore preferred. They can be pulverized very well and optimally mixed with the PVC resin. They also contain less lignin (only about 5%) and therefore bleach less or not at all under the influence of the weather (sun, rain).

In one embodiment of the composition to be used according to the invention for producing an imitation wood, the PVC resin and the rice and / or peanut shell powder are mixed in a ratio of approximately 50:50. The mix order is generally arbitrary.

In a further embodiment of the composition according to the invention for producing an imitation wood, one or more of the following additives or additives are / are also added to the mixture of PVC resin and / or rice and / or peanut shell powder: chemical binder (s) Thermoplastic base (e.g. poly (meth) acrylate), color pigment (s) (e.g. chalk, titanium dioxide, carbon black, red iron oxide, ocher), lubricants or lubricants (e.g. fatty acid salts such as calcium stearate, fatty acid esters, fatty acid amides, paraffin waxes, polyethylene waxes, microcrystalline paraffin) , Calcium carbonate and PVC processing aids ("processing aids") (eg heat and weather stabilizers, antioxidants, anti-aging agents, light stabilizers, ultraviolet absorbers, antistatic agents). The aforementioned additives are available from specialist dealers. The additional components can be mixed with the PVC resin and the rice or peanut shell powder at the same time or in several stages.

A further embodiment of the composition to be used according to the invention for producing an imitation wood contains a mixture of 30-40% by weight, for example 31-37% by weight, PVC resin, 30-40% by weight, for example 33-36% by weight. %, Rice and / or peanut shell powder with a particle size of 0.42-0.25 mm (40-60 mesh), 8-12% by weight, and optionally, for example 7-9% by weight, chemical ( r) thermoplastic-based binder, 0.5-1% by weight of color pigment (s), 2-4% by weight of lubricant or lubricant, 12-18% by weight, for example 11-15% by weight, Calcium carbonate and 8 - 12 wt .-% PVC processing aids.

The chemical binder based on thermoplastic materials, for example, has the function of removing moisture or solvents from natural material fibers and strongly connects or interlinks with the “nonwoven web” or network of natural material fibers. PVC processing aids ("PVC processing aids") can accelerate the fusion ("Fusion"), the melt strength bw. Improve melt toughness, eliminate surface defects and reduce the place out. They can also enhance the metal release properties in the production process. Suitable binders and processing aids are known to the person skilled in the field of PVC processing and are commercially available in a large selection.

In a further embodiment of the composition according to the invention for producing an imitation wood, the PVC resin particles and the rice or peanut shell powder have approximately the same grain size.

The imitation wood to be used according to the invention can be produced by extrusion of a composition described here. The product obtained by extrusion is usually in the form of a plate or strip, so that it can be easily connected to the at least one layer of wood.

The extrusion process used is not particularly restricted. Any commercially available extruder can be used. The operation follows the Manufacturer's instructions. It is clear to the person skilled in the art that the composition according to the invention must be homogenized and liquefied sufficiently under the extrusion conditions (for example temperature and pressure) so that it can be pressed through the extruder nozzle. Suitable extrusion conditions are either those specified by the manufacturer or are determined by a person skilled in the art by simple routine tests. As is known, the geometry of the extrusion die used determines the shape or profile of the extrusion product obtained. The product obtained by extrusion can, for example, have the shape of a plate or be a profile.

For example, the PVC resin is mixed in a high-speed mixer with dried rice husk powder (particle size 40-60 mesh, moisture content e.g. 0.5 to 1.0%) and optionally filler (e.g. calcium carbonate) for 5 minutes at 125-140 ° C. The optional additives such as color pigment, stabilizer, processing aids, lubricants (e.g. epoxy soybean oil, wax) are mixed in a small mixer / blender for 10 minutes and then added to the mixture of PVC resin / rice husk powder / filler in the high-speed mixer. Then the entire mixture is mixed homogeneously for a further 10 min. Finally, the mixture is allowed to cool in a cooling tank for about 30 minutes and then extruded with a twin or twin screw extruder at a controlled temperature in the range of, for example, 150-210 ° C. or 160-175 ° C. to give the imitation wood as the end product.

The plastic skin formed on the surface of the extrusion product is preferably removed after the extrusion. This creates the very wood-like feel and look of the imitation wood, which improves the use in combination with wood with regard to the look of the end product. By removing the plastic skin, the imitation wood also has good slip resistance. The color tone of the imitation wood can be controlled by the color pigments contained in the composition used for its production. Conveniently, no intensive shade is set, but a comparatively rather paler one. The final desired shade is then set by painting or glazing the product made from the imitation wood. This saves the production and storage of a large number of imitations of wood with different colors.

For example, the plastic skin can be removed by grinding. Grinding can e.g. with an abrasive material such as sand or sand paper with a grain size in the range from 24 to 300, for example using an electrically operated hand grinder. A smaller numerical value stands for a coarser grain and a higher numerical value for a finer grain. A grain size of 24 is rather coarse and is suitable e.g. for removing glue or varnish layers, while a grain size of 60 is rather medium and is used, for example, for rough pre-grinding of raw wooden surfaces. Finer grits may then be used to finish a smooth and optically fine surface. The person skilled in the art chooses the suitable grain size in accordance with the practical circumstances or the effect to be achieved.

Alternatively, the plastic skin can also be removed in another way, for example by planing or sandblasting.

In a further embodiment of the imitation wood, its surface is lacquered, glazed or oiled, if necessary after a corresponding pretreatment (e.g. primer). For example, water-based one-component paints are suitable for painting. Two-component paints are particularly suitable for extreme use. Non-opaque glazes and lacquers can be used, but of course opaque paints, such as color lacquers, are selected depending on the application. Elements for conservatories etc. are often designed with an opaque white color.

Depending on the pigmentation and surface tint, different wood looks and haptics can also be realized, e.g. of tropical wood such as Burma teak, Siam teak, Java teak or aged teak, but also of wood such as larch etc. which are often used in window and door construction.

Due to its stability, dimensional stability and absolute resistance to the effects of moisture such as rain, the imitation wood to be used according to the invention is far superior to conventional wood / PE composites (WPCs) and also many types of wood. Surfaces made from imitation wood, for example window or door elements, are almost waterproof. The PVC used is not hygroscopic and does not absorb water and thus prevents water from penetrating even if the surface is damaged, so that the applied layers of paint do not infiltrate and no paint flaking occurs. The imitation wood to be used according to the invention is therefore also dimensionally stable, so that it cannot be deformed naturally (e.g. by swelling or shrinking). Conventional wood / PE composites swell under the influence of moisture. Varnishes no longer adhere because the penetrating water infiltrates them and thereby detaches them.

The imitation wood or the material according to the invention has a very wood-like appearance and feel on the surface provided with the imitation wood, and in many respects alone offers significantly improved properties compared to the vast majority of types of wood.

Due to the polar properties of the PVC used, the surface of the imitation wood can be oiled, varnished or varnished without any problems, so that the new material is particularly suitable for the manufacture of the above-mentioned elements. The polar properties also allow easy adhesion and confer antistatic properties. Conventional wood / PE composites (WPCs) are not or only very difficult to paint due to the non-polar properties of PE, cannot be glued and are not antistatic.

Due to the excellent strength, it is possible to drive in nails or screw in screws into the imitation wood as with conventional wood materials. Machining is also problem-free, making it easy to cut through with a saw, drilling, milling, grinding or even sandblasting. The imitation wood does not crack or splinter, and cut waste is 100% recyclable.

The material according to the invention is therefore particularly suitable for the production of elements for the production of windows or doors or other structural elements and borders, with or without inserts, such as glass inserts, as are used, for example, in winter gardens in which one side is exposed to the weather. These elements, such as window scantlings, etc. can be produced from the material in a conventional manner, since the material according to the invention can be processed like wood.

In the material according to the invention, the respective layer thicknesses for the layer made of imitation wood and the at least one layer made of wood can be chosen freely, depending on the desired application. Layer thicknesses in the range from 0.5 to 10 cm, preferably 1 to 8 cm, have proven to be suitable. Typically, the imitation wood layer is thinner than the wood layer (s). The thickness of the layer of imitation wood is preferably set so that it is ensured during end use that only the layer of imitation wood is exposed to the weather (while the layer of wood is protected beneath it).

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 2536785 A [0009]

Claims (10)

Material comprising at least one layer of wood and a layer of imitation wood, the layer of imitation wood comprising a polar thermoplastic resin, such as PVC, and a cellulose-containing component, such as rice or peanut shell powder. Material after Claim 1 , the imitation wood containing 30-40% by weight of PVC resin and 30-40% by weight of rice and / or peanut shell powder with a particle size of 0.42-0.25 mm (40-60 mesh), preferably wherein the PVC resin and the rice and / or peanut shell powder are mixed in a ratio of about 50:50. Material after Claim 1 or 2 , the wood of the at least one layer of wood being selected from pine, larch, oak or beech. Material according to one of the Claims 1 to 3 , wherein the at least one layer of wood and a layer of imitation wood are glued together. Material according to at least one of the Claims 1 to 4 , wherein the imitation wood layer and the at least one wood layer each have a thickness of 0.5 to 10 cm. Method for producing a material according to at least one of the Claims 1 to 5 , comprising the gluing, optionally using a press, a layer of imitation wood with a layer of wood. Use of the material according to one of the Claims 1 to 5 or get after Claim 6 for the production of elements in which a surface is exposed to the weather in the end application. Use after Claim 7 , the elements being selected from elements for the production of windows or doors. Product comprising the material according to one of the Claims 1 to 5 or made after Claim 6 , the product being selected from products in which a surface is exposed to the weather in the end use. Product after Claim 9 , are selected from products for the manufacture of windows or doors.