DE10354394B4 - Binders for the production and bonding of wood-based materials and / or fibrous materials and use thereof - Google Patents

Abstract

binder for the production and bonding of wooden materials and / or fibrous materials, characterized in that the Binder an acetone-formaldehyde reaction product, a proteinaceous component and a thermally crosslinkable acrylate component, wherein the proportion of acetone-formaldehyde reaction product in the binder in the range of 5 wt .-% to 75 wt .-%, the proportion of proteinaceous component in the binder in the range of 5 wt .-% to 75 wt .-% and the proportion of acrylate component in the binder in the range of 5 Wt .-% to 75 wt .-%, each based on the solids content of Bindemittels lies.

Description

The The invention relates to a binder for the production and bonding of wood-based materials and / or fibrous materials and its use.

Phenolic resins are the most traditional binder for the production of moisture-resistant wood-based materials and have been proven in practice for many decades and have been constantly developed. ( DE 3346153 ; US 6,489,392 )

The fields of application range from chipboard over MDF (Medium Density Fiberboard) to OSB (Oriented Strand Board) and fiber glueing, eg for use as molded parts in the automotive industry or the door industry ( DE 19956765 ). In addition to phenol resins, both urea-formaldehyde (UF), melamine-formaldehyde (MF), melamine-urea-formaldehyde (MUF) and melamine-urea-phenol are used for the production / coating of wood-based materials for general applications and the production of moisture-resistant wood-based materials. Formaldehyde resins (MUPF) and polymeric diisocyanate (PMDI) as the most noteworthy binder used successfully and in very large quantities and depending on the application, their specific advantages and, of course, disadvantages. These advantages and disadvantages relate in particular to reactivity, moisture resistance of the bond, costs of the binder, color of the bond.

This has meant that these binders sometimes compete with each other in terms of the specific application and the user decides, inter alia, according to plant technology or company philosophy, which binder he wants to use. In addition, market and customer-specific decisions help determine the direction in which the binder systems are used and further developed. For the realization of customized solutions, mixtures of thermosetting binders are also discussed and used. ( US 4,209,433 ; US 6,214,265 )

specially such topics as emissions as well as disposal (material cycle) the wood-based materials generally produced with synthetic binders continue to unsettle the end user and have basic Rethinking processes initiated.

Especially The automotive industry is concerned with the odor and environmental problems extremely critical of. This is how the call for phenolic resin-free materials for the automotive interior area getting bigger. (. 11 Braunschweiger Holztechnisches Kolloqium, lecture 10; 4th International Symposium Materials made from renewable raw materials, Erfurt September 2003)

Next The above-mentioned synthetic binders are used again and again natural Binders brought into the discussion, which during processing in suitable Form into a quasi-insoluble one Condition must be brought.

The common natural Binders are based on polyphenols (tannins / lignins), polysaccharides (Starchy Products) and proteins (plant and animal basis).

Out Century-old practice is known that made with natural binders adhesive joints can be.

adversely is at the natural Binders their low moisture resistance. With increasing industrialization and the associated necessary increases in effectiveness were a variety the natural one Binders pushed back, lost in importance and even partially forgotten.

In In recent decades, people have remembered this natural one again Products especially against the background of scarcity of resources, emissions from the glued wood-based materials and the required closed material cycles.

There are extensive scientific publications and patents in which combinations of natural components or binders with synthetic binders are described to at least partially meet the upcoming tasks. (WO 93/21260; WO 94/24192; EP 1318000 )

there act the natural Components as fillers in synthetic binders or are used as a partial replacement synthetic components in the reaction to make the binder with consulted. With that you can Both cost advantages and benefits in terms of emissions and disposal, but only too often by inefficiency in the processing for the production of wood-based material products pushed into the background and partially oppose the use of such binder systems stand.

task The invention is a reactive binder with possible low environmental impact, d. H. with the lowest possible emissions at environmentally hazardous or hazardous to health chemical substances. In addition, such should be one Binder economically producible and easy to process be.

The The object underlying the invention is achieved by a binder for the production and bonding of wood-based materials and / or fibrous materials according to claim 1 solved.

The Task will continue through the use of this binder for the production and bonding of wood-based materials and / or fibrous materials solved.

preferred embodiments are each in the subclaims specified.

Under an acetone-formaldehyde reaction product is in the context of the invention understood a reaction product of acetone and formaldehyde, the preferably under neutral to alkaline conditions in aqueous solution is produced. The molar ratio of acetone to formaldehyde preferably 1: 2 to 1: 5, preferably 1: 2.5 to 1: 4. The acetone-formaldehyde reaction product is preferably in a range of pH 7-12, more preferably in the pH range from 7 - 10 and especially in the pH range of 7-9, wherein the pH at 20 ° C is measured. The reaction is preferably carried out in aqueous solution with the addition of basic substances, preferably lye, for example. Sodium hydroxide.

When proteinaceous component can both animal and vegetable proteins are used. The proteins can present as protein fragments or else as protein hydrolysates. The Proteins can in dried form or in solution or used as suspension or dispersion. Preferably the proteins are water-soluble. The proteins can natural Origin or of synthetic origin. For example. is it possible to genetically engineered use prepared proteins.

Under the term "proteinaceous Component "becomes in the sense of the invention understood that the component exclusively or Part consists of protein, protein fragments and / or a protein derivative. In addition to the protein can in the proteinaceous component also other components such as Carbohydrates such as sugar may be included.

Preferably is used as a proteinaceous component on plant proteins based component used. Preferably, the vegetable Protein is a cereal protein, preferably a wheat protein.

in the According to the invention, it is not necessary that it is a pure or purified protein. Rather, the term "protein" also includes mixtures of "proteins." That is, in which preferably used wheat protein may be both a certain protein as well as a protein mixture isolated from wheat or in the processing of wheat accumulating, preferably water-soluble, proteinaceous by-products.

According to one another preferred embodiment is the thermally crosslinkable acrylate component from the group the acrylic acid compounds, in particular the acrylic acid ester or polymeric acrylic acids selected.

When acrylate can the usual Esters such as, for example, methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, tert-butyl, Amyl, isopentyl and / or hexyl esters can be used.

The Inventive binders is preferably thermally crosslinkable or curable. According to a preferred embodiment the thermal crosslinking takes place in a temperature range of 100 ° C to 250 ° C, preferably from 100 ° C up to 200 ° C. The thermal crosslinking can be carried out by application of dry or damp heat be induced.

Preferably the thermally crosslinkable acrylate component is in aqueous Shape, for example as a solution, Suspension or dispersion.

Farther is preferred that the binder is present in total as an aqueous solution.

The However, binder may also contain organic solvents, wherein it is preferred that the solvent is predominantly Water, preferably substantially water, is. Especially preferred is the solvent exclusively Water.

According to the invention the proportion of acetone-formaldehyde reaction product in the binder in a range of 5% by weight - 75 Wt .-%, preferably in a range of 10 wt .-% to 50 wt .-%, in each case based on the solids content of the binder according to the invention.

According to the invention the proportion of proteinaceous component in the binder in the range from 5 wt% to 75 wt%, preferably in the range of 10 wt% to 60 wt .-%, each based on the solids content of the binder according to the invention.

According to the invention, the proportion of acrylate component in the binder in a range of 5 wt .-% to 75 wt .-%, preferably in the range of 10 wt .-% to 70 wt .-%, in particular from 20 wt .-% to 70 wt .-%, in each case based on the Solids content of the binder according to the invention.

The Addition of the aforementioned components results, taking into account optionally further solids present, in each case 100% by weight.

Of the Proportion of water or aqueous Solution in the Binder is preferably in a range of 30% by weight to 70 wt .-%, more preferably from 40 wt .-% to 60 wt .-%, based on the total weight of the binder, d. H. Solids and solvents or water.

The viscosity of the binder is at 20 ° C preferably less than 1000 mPas, more preferably less than 600 mPas. According to one another preferred embodiment is the viscosity of the binder at 20 ° C less than 300 mPas.

The Inventive binders is extremely beneficial a low viscosity binder. The low viscosity of the binder according to the invention allows easy processing. For example. can the binder of the invention easy and reliable on wooden materials to be joined or glued together be applied.

The Inventive binders is extremely advantageous a high reactivity on and allows therefore a fast and reliable Curing. The is called, glued using the binder of the invention or bonded wood or fiber materials can processed in an advantageous manner after a short time or-processed become.

According to one another preferred embodiment The binder is used in combination with thermosetting Binders which are preferably selected from the group urea-formaldehyde (UF), melamine-urea-formaldehyde (MUF), melamine-urea-phenol-formaldehyde (MUPF), Melamine formaldehyde (MF), phenol-formaldehyde (PF), phenol-urea-formaldehyde (PUF), resorcinol-phenol-urea-formaldehyde (RPUF), resorcinol-phenol-formaldehyde (RPF), polymeric diisocyanate (PMDI) resins and mixtures thereof is used.

According to one another embodiment The invention relates to the binder according to the invention in combination with thermoplastic binders, preferably from the group selected are made of polyvinyl alcohols, polyvinyl acetals and mixtures of which is used.

D. h., The binder of the invention is advantageously compatible with conventionally used binders and can replace them to some extent. This can advantageously the proportion of conventional Binders by partial exchange against the binder of the invention be lowered.

The Inventive binders is characterized by the fact that it is both alone and in combination with conventionally used binders can be used. This allows extremely advantageous one for appropriate setting of the binder for each purpose.

The Inventive binders is particularly suitable for bonding wood-based materials and / or Fibers. The fibrous materials are preferably around plant fibers. According to one preferred embodiment the plant fibers are fibers of annual plants.

When Plant fibers are preferably wood, flax, hemp, sisal, Bast, jute or mixtures thereof used.

Farther becomes the binder according to the invention preferably in combination with wood fibers and / or synthetic fibers, for the production of fiberboard, fiber mats or molded fiber parts uses.

When Synthetic fibers are preferably polypropylene, polyester, polyamide fibers or mixtures thereof.

According to one another preferred embodiment The fibers are inorganic fibers such as mineral fibers and / or glass fibers. The mineral fibers may be, for example, ceramic fibers be.

The Inventive binders is particularly suitable for the production and bonding of wood-based materials like chipboard, fiber or OSB boards.

insofar the binder according to the invention is suitable also for the processing of wood waste or residues caused by Shredders are converted into fibers and / or shavings.

Surprisingly could be found, the hybrid binder thus prepared itself by a very high reactivity, also opposite used individual components, characterized by what an example explained shall be.

example

There are 20 parts by weight of an aqueous acetone-formaldehyde reaction product (mol ratio of acetone: formaldehyde = 1: 4), characterized by a content of non-volatile constituents of about 50% and a reactivity expressed as B time at 130 ° C of> 10 min with 30 parts by weight of a protein-containing aqueous suspension (wheat-soluble from. CERESTAR Deutschland GmbH) with a content of non-volatile constituents of about 30 and a not definable B-time at 130 ° C (the product dries only one) mixed. The resulting 50 parts by weight of product are in turn mixed with 50 parts by weight of a thermally crosslinkable acrylic acid ester (Policril / ^® 309 / R, FAR, Italy) with a non-volatile content of about 50% and a B-time at 130 ° C of> Mixed for 2 minutes.

The thus produced binder has a content of non-volatile Constituents of approx. 45% and a reactivity, expressed as B time at 130 ° C., of approx. 2 min at a viscosity of about 150 mPas / 20 ° C.

The B time is determined according to DIN 16916-02-C2.

Of the Content of non-volatile In each case, constituents are determined in accordance with DIN 16916-02-H1.

To similar Results are also obtained when considering the proteinaceous component at the beginning or during the preparation of the acetone-formaldehyde reaction product at elevated temperature, for example 50 ° C, into the system and then the acrylate component added there.

It could thus surprisingly be found that at suitable combination of the individual components mentioned a binder can be produced with significantly improved reactivity, resulting in Consideration of the individual components would not have been expected. It will thus giving the consumer a binder system which comparable reactivities and parameters such as synthetic binders while providing significant Proportions of natural Contains binder.

Claims (21)

Binder for the production and bonding of wood-based materials and / or fibrous materials, characterized in that the binder comprises an acetone-formaldehyde reaction product, a proteinaceous component and a thermally crosslinkable acrylate component, wherein the proportion of acetone-formaldehyde reaction product in the binder in the range from 5% by weight to 75% by weight, the proportion of proteinaceous component in the binder in the range from 5% by weight to 75% by weight and the proportion of acrylate component in the binder in the range from 5% by weight to 75 wt .-%, each based on the solids content of the binder. Binder according to claim 1, characterized in that that this Binder thermally curable is. Binder according to claim 1 or 2, characterized that this Acetone-formaldehyde reaction product in the pH range, measured at 20 ° C, 7 - 12, preferably 7-10, especially 7 - 9, is present. Binder according to one of the preceding claims, characterized characterized in that proteinaceous component on plant proteins, in particular on wheat protein, based component. Binder according to one of the preceding claims, characterized characterized in that proteinaceous component in water-soluble, solid form, as a solution, suspension or dispersion is present. A binder according to any one of the preceding claims characterized characterized in that thermally crosslinkable acrylate component is selected from the group those made from acrylic acid compounds, especially acrylic acid esters, polymeric acrylic acids and their mixtures exist. Binder according to one of the preceding claims, characterized characterized in that thermally crosslinkable acrylate component is present in aqueous form. Binder according to one of the preceding claims, characterized characterized in that Binders as aqueous solution is present. Binder according to one of the preceding claims, characterized characterized in that Proportion of acetone-formaldehyde reaction product in the binder in Range from 10 wt.% To 50 wt.%, Each based on the solids content of the binder lies. Binder according to one of the preceding claims, characterized characterized in that Proportion of proteinaceous component in the binder in the range of 10 wt.% To 60 wt .-%, each based on the solids content of the binder lies. Binder according to one of the preceding claims, characterized characterized in that Proportion of acrylate component in the binder in the range of 10% by weight up to 70% by weight, in each case based on the solids content of the binder, lies. Binders according to one of the preceding An Claims, characterized in that the viscosity of the binder at 20 ° C less than 1,000 mPas, preferably less than 600 mPas. Binder according to claim 12, characterized in that that the viscosity of the binder at 20 ° C less than 300 mPas. Binder according to one of claims 1 to 13, characterized that it in combination with thermosetting binders, preferably selected from the group are made from urea-formaldehyde (UF), melamine-urea-formaldehyde (MUF), melamine-urea-phenol-formaldehyde (MUPF), melamine-formaldehyde (MF), phenol-formaldehyde (PF), phenol-urea-formaldehyde (PUF), resorcinol-phenol-urea-formadehyde (RPUF), resorcinol-phenol-formaldehyde (RPF), polymeric diisocyanate (PMDI) resins and mixtures thereof is present. Binder according to one of claims 1 to 14, characterized that it in combination with thermoplastic binders, preferably selected from the group made of polyvinyl alcohols and polyvinyl acetals and mixtures thereof exists. Use of a binder according to one of claims 1 to 15, for the production and bonding of wood-based materials and / or Fibers. Use of a binder according to claim 16, preferably in combination with wood fibers and / or synthetic fibers, for the production of fiberboard, fiber mats or molded fiber parts. Use according to claim 16 or 17, characterized that the Fibers Plant fibers, preferably vegetable fibers of annual plants are. Use according to claim 16, characterized that the Fibers inorganic fibers, preferably mineral fibers and / or glass fibers. Use of a binder according to one of claims 1 to 13 in combination with thermosetting binders, preferably selected from the group are made from urea-formaldehyde (UF), melamine-urea-formaldehyde (MUF), melamine-urea-phenol-formaldehyde (MUPF), melamine-formaldehyde (MF), phenol-formaldehyde (PF), phenol-urea-formaldehyde (PUF), Resorcinol-phenol-urea-formaldehyde (RPUF), resorcinol-phenol-formaldehyde (RPF), polymeric diisocyanate (PMDI) resins and mixtures thereof. Use of a binder according to one of claims 1 to 13 in combination with thermoplastic binders, preferably selected from the group are made of polyvinyl alcohols and polyvinyl acetals and mixtures of which consists.