EP2300202A1

EP2300202A1 - Method of reducing emissions from wood and wood-based materials

Info

Publication number: EP2300202A1
Application number: EP09769080A
Authority: EP
Inventors: Katharina Wiegner; Oliver Jann; Olaf Wilke; Harald Scheffer
Original assignee: Bundesanstalt fuer Materialforschung und Pruefung BAM
Current assignee: Bundesanstalt fuer Materialforschung und Pruefung BAM
Priority date: 2008-06-27
Filing date: 2009-05-19
Publication date: 2011-03-30
Also published as: WO2009156258A1; DE102009000335A1; WO2009156231A1; DE102009000109A1

Abstract

The invention relates to a method of producing wood-containing intermediates for further processing to wood-based materials, more particularly OSB, and solid wood products, comprising the following steps: a) using wood-containing starting materials; b) wetting the wood-containing starting materials with a solution comprising tartaric acid and/or tartaric acid tartrates.

Description

Method for reducing emissions of wood and wood-based materials

The invention relates generally to the field of making wood products and solid wood products. In particular, the invention relates to a process for the production of wood-containing intermediates for further processing into wood-based materials and solid wood products. The invention also novel novel wood-containing intermediates and derived wood materials and solid wood products.

Wood materials and solid wood products are widely used today and are found in many everyday products, e.g. in the manufacture of furniture, buildings or parts of buildings, or toys, to name just a few uses. Naturally, the products of wood-based materials and solid wood are mostly and for a long time in the immediate vicinity and environment of humans and animals, e.g. in the case of wooden furniture, construction wood, wall, floor and ceiling coverings preferred especially in confined spaces.

A particularly important requirement of wood-based materials and solid wood products or products containing them is therefore sufficient compatibility to preclude health hazards or impairments. In particular, emissions of such pollutants play an important role, e.g. Effects on the health of humans and animals can have or can be perceptible to smell and are thus perceived as annoying.

For the protection of consumers and persons involved in the production and distribution of such products, the legislator has already set legal limits for some emissions and it is expected that the scope of such regulations will increase and the limits of existing regulations tend to increase be lowered. An example of how such limits are implemented and measured is the assessment of construction products, which can include wood-based products and solid wood products. The assessment of construction products is based on the scheme of the Committee for the Health Assessment of Construction Products (AgBB). For health assessment, the product undergoes a series of tests defined in the flowchart shown in Figure 1. For a variety of indoor relevant VOC (VOC = volatile organic compounds, volatile organic compounds, SVOC = semivolatile organic Compounds) are listed as health-related auxiliary quantities so-called NIK values (lowest concentrations of interest). These NIK values are relatively small for aldehydes and in particular unsaturated aldehydes, ie even low emissions can lead to a rejection of the construction product. Therefore, it is important to reduce the emission of pollutants from wood products, especially aldehyde emissions.

A class of substances whose emission from wood-based materials and solid wood products is already well-known represent the saturated and unsaturated aldehydes. Aldehydes are volatile organic compounds that are perceptible to the smell of odor and, above all, can be hazardous to health in larger concentrations. This applies in particular to unsaturated aldehydes.

These aldehydes arise largely by oxidation of fats contained in the wood-containing starting materials. These oxidation reactions are also affected by the necessary production conditions for wood-based materials and solid wood products, such as, for example, Comminution of the wood to the desired wood-containing starting materials, drying and pressing at low and high temperatures of wood-containing starting materials favors. Thus, there is a need for a process which can reduce the emission of pollutants, such as e.g. reduced by aldehydes, wood materials and solid wood products or their intermediates.

In WO 06/032267 a process is described for the treatment of wood or wood particles with the aim to reduce a release of unsaturated aldehydes. In particular, a 1.5% sodium citrate solution and a 1% octyl ester gallate acid dispersion have been used. The use of these solutions actually resulted in a reduction in aldehyde emission, however, a relevant residual emission is still detectable.

The object of the invention is to provide improved methods and means enabling the emission of pollutants, such as e.g. aldehydes and / or terpenes, from HoIz materials and solid wood products or their intermediates to further reduce.

This object is achieved by the invention by providing a process for the production of wood-containing intermediates for further processing into wood-based materials and solid wood products. This process comprises the following steps: a) use of wood-containing starting materials, b) wetting of the wood-containing starting materials with a solution containing tartaric acid and / or tartaric acid tartrate.

The individual agents and process steps according to the invention are described in more detail below.

Wood materials: Wood materials in the context of the present invention are composed of wood layers of different thickness, these wood layers containing wood particles. Such wood particles may be wood strips, wood chips or wood fibers of the same or different woods, a certain size or different size.

Usually, plate-shaped or strand-shaped wooden materials are produced by mixing the various types of wood particle with natural and synthetic binders and optionally adding further additives, for example water repellents, in the course of a subsequent hot pressing.

Selected forms of wood-based materials are:

Plywood. As plywood or plywood wood panels are called, which consist of several superimposed veneer or board layers. The layers are glued to each other rotated by 90 ° or can be parallel. The fibers of the visible surfaces run parallel on both sides. The number of veneer layers is therefore mostly odd. In some areas, however, glueing has been in progress for some time. This is done so as not to get into a cross-veneered surface during regrinding (for example in the case of stairs). Only today's quality of glues allows such a construction.

Composite panels: In this case, they are multi-layered materials.

Most high-strength cover layers are combined with light middle layers, which results in a weight saving.

Wood-chip materials, such as chipboard, chipboard and fiberboard: - Chipboard, also OSB (English: oriented Strand (or structural) board)

- slab of oriented chips, OSB) are multilayer boards made from long, slender shavings (strands). These chips preferably have an average length of 2 to 20 cm. The preparation of the OSB boards is usually done in processes comprising the following steps:

• Chip preparation: The strands or shavings are cut lengthwise from the debarked roundwood by rotating knives.

• Drying: The natural moisture of the chips is reduced at high temperatures. This is necessary to be able to then wet the chips with sufficient adhesive. In addition, may not be too much during the pressing process

Moisture in the chips be present, otherwise the resulting vapor pressure could cause the raw plate to burst (drying temperature up to 500 ⁰ C).

• Gluing: The adhesive is applied finely distributed to the chips. • Scattering: The about 20-200 mm long, 10-50 mm wide and 0.6-1, 5 mm thick chips are scattered in the throwing process longitudinally and transversely oriented so that they are arranged crosswise in usually three layers.

• Pressing: under high pressure and temperature (press temperature up to

250 ⁰ C) the strands are mostly made on continuous presses. • Possibly. then re-drying the pressed plates.

For bonding, preference is given to PF adhesives (phenoplast), MUPF adhesives (melamine-urea-phenol-formaldehyde), urea-formaldehyde adhesive, UF adhesive for short, melamine-containing urea adhesives, MUF adhesives for short and PMDI adhesives (Polymeres Diphenylmethane diisocyanate), being mainly from qualitative

The proportion of PMDI predominates. Very often in the middle layer PMDI is used and in the outer layers MUF or MUPF adhesives.

- Fiberboard, for example MDF (Medium Density Fiberboard): From very finely fused, mainly bark-free softwood and a gentle compression is a in

Longitudinal and transverse direction produced equally homogeneous wood material.

• Processing: As raw material for the production of wood fiber, mainly round wood (logs), wood chips, rinds and to a lesser extent waste wood, remaining rolls of peeled veneer production, veneer residues and sawdust are used. • Wood chips production: Round wood is debarked in most cases and minced in wood chippers or as well as the rinds or waste wood in drum chippers. The chips are sorted before further processing (sieved) and usually dry or wet cleaned of sand and stones.

• Defibration: The woodchips then enter the hydrochemical pretreatment in a predampening tank, then in the digester and then in the refiner (shredder). The shredded fabric is blown out of the refiner via an adjustable "blow valve" through the "blow pipe". The refiner also has six to ten bar steam pressure. The steam forms the transport means for the fibers on their way through the blow pipe into the dryer.

• Drying: After defibering, the pulp - unlike chips - is dried with electric dryers (mostly heated directly with flue gases or burners). The pulp is placed in the hot exhaust stream and dried in the drying channel during pneumatic conveying. In the end, the

Fibrous material with about 5-10% wood moisture in cyclones separated from the air flow.

• Glueing: In most cases, urea-formaldehyde resins (urea resin, urea-formaldehyde => UF) are used for gluing. These resins may be reinforced with melamine or phenol to improve the moisture resistance of the size compound. Only in rare cases are isocyanates (polymeric diphenylmethane diisocyanate - PMDI) used as a sizing system. In newer UF gluing systems, the molar proportion of formaldehyde compared with urea is being further reduced in order to comply with the legal requirements regarding the formaldehyde emissions of wood-based materials (Class E1, E2 in Europe and F ^**** in Europe)

Japan) better to be able to comply. Three types of gluing are distinguished: mixer gluing, blow-line gluing, dry gluing.

• Fiber direction: In most of today's MDF plants, the fibers are cleaned after the drying process (or, if available, only after re-lamination) in a fiber separator. The fibers are placed in a stream of air and freed as far as possible either by vortex formation, sharp deflections, impact vision, Steigluftsichtung or a combination of several effects of heavy particles (glue lump, rubber, metal). Subsequently, the fibers are again separated by cyclone from the air flow and fed to the forming station. • Forming and pressing: Scattering: The scattering station consists of one

Dosing bunker, a mat diffusion and a mat smoothing. Forming line: After the scattering station, the fiber mat is weighed and the fiber moisture is measured. The shaping then passes into the pre-press. Here, the formation is reduced in the cold pre-compaction in thickness, so that the hot presses can be fed more efficiently and the risk of damage to the moldings is reduced. In the pre-compaction in the run is usually worked with belt pre-pressing, according to the principle of the conveyor belt (rarely with apron pre-presses, according to the principle of the tank chain, or with Walzenbandvorpressen, according to the principle of pyramid stone transport with round timbers). After

Prepress follows the mat trimming, in which side strips are separated from the fiber mat, so that the corresponding desired plate width can be produced. Other measuring devices for density control or metal detection may follow. Also a Mattenbesprühung to improve the surface qualities or acceleration of the Mattwartwärmung can follow. Hot Press: This is followed by the hot pressing, where clocked or continuously worked. Fiberboard is made on calender presses. The compression takes place here with press rolls and an outer band on a heated calender roll.

- For reasons of cost, chipboard is mainly produced from wood residues and thinnings. Different wood particles are used, which can differ in the type of wood as well as in the particle size. The actual production process comprises the steps: comminution (cutting) of the wood to desired wood particles; Drying of the wood particles; gluing; pressing; optionally a subsequent drying step of the chipboard. Furthermore, adhesives (wood glues and cement milk) are used to connect the chips and various wetting and separating agents for the pressing process.

Thermowood: Thermowood is the end product of a thermal treatment of wood.

This method physically works by vigorously heating the wood. The aim of the treatment is to modify the technical properties of the building material wood and thus to improve its suitability for certain purposes. Differentiation to other methods: In these thermal wood treatments temperatures of degrees 170 ⁰ C to 250 ⁰ C are used. The thermal treatment of woods can be short term or over 24-48 hours, partially in the absence of oxygen or in a steam atmosphere. Thermowood is to be distinguished from a damping or fumigation.

Solid wood products: For the purposes of the present invention, solid wood products are wood products which essentially consist of solid wood or solid wood parts. Solid wood refers to wood-containing starting materials whose cross-sections have been worked out of a tree trunk and possibly further processed by machining, without any changes being made to the structure of the wood.

Wood-containing starting materials:

The term wood-containing starting materials in the context of the present invention includes all wood-containing substances which can be used as starting material for the production of wood-based materials or solid wood products. Preferred wood-containing starting materials are wood particles or wood parts, as used in the production of chipboard, OSB boards or other wood materials (fiber, carpenter Funierplatten) use and solid wood parts, such as those used in the manufacture of solid wood products including glued wood.

Adhesive: Adhesives which can be used according to the invention include all adhesives which are suitable for the production of wood-based materials or solid wood products and their additives, such as those known to the person skilled in the art. Binders, waxes, resins, glues, cementmilk, PF adhesives (phenoplast), MUPF adhesives (melamine-urea-phenol-formaldehyde), UF adhesive (urea-formaldehyde adhesive), MUF adhesives (melamine-containing urea adhesives) Adhesives) and PMDI adhesives (polymeric diphenylmethane diisocyanate).

Binder based on renewable resources: tannins

Tannins are vegetable polyhydroxyphenols (tannins) which are soluble in water, alcohols and acetone. Tannins are mainly extracted by extraction from wood, bark, leaves and fruit. There are numerous studies on the use of extractives from bark of mimosa and bark of various pine species.

Chemically, the tannins are divided into hydrolyzable and condensed types. The use of tannins as a binder is carried out either with a formaldehyde component as a crosslinker or in combination with amino or phenolic resins. Preferred glues are selected from:

- Glutin glue: Glutin glue is a natural glue that is made from skin, leather or bone waste. Casein glue: This glue consists of milk and lime. Resorcinol-formaldehyde resin glue (also called RF glue): Consists of liquid glue and pulverulent hardener.

- Formaldehyde-poor polycondensation glue: Formaldehyde is needed to harden the glue resins. In most cases, the formaldehyde content is higher than that of the other resin constituents to ensure good cure (stoichiometric excess). However, in the case of this polycondensation glue, the reduction of free formaldehyde is achieved by addition of formaldehyde scavenger or reduction of the formaldehyde content.

Formaldehyde-free dispersion glue: The known white glue is a formaldehyde-free dispersion glue based on PVAC (polyvinyl acetate) as a binder which is supplied ready for use in water as a dispersion and is available as cold glue, quick binder, veneer glue, hardener glue, lacquer glue and hot glue. It is available in the stress groups D2-D3. For D4 gluing, a D3 glue is required, to which hardener is added before consumption. There are also D2 glues, which reach the D4 quality with the addition of a hardener.

- PU glues: Today, the most modern glues for the wood industry are the one-component PU glues (polyurethanes). They are waterproof (D4) and not only glue wood, but almost all sticky materials. These are solvent-free reaction adhesives that cure with the help of moisture.

Solvent for providing solutions containing tartaric acid and / or tartar tartrate:

Suitable solvents are solvents in which the desired antioxidants and / or preservatives and optionally further constituents of the solution, such as adhesives, can be dissolved sufficiently well and which are suitable for use on wood-containing starting materials. These are preferably water, or other organic solvents, such as, for example, alcohols. Suitable solvents include mixtures of water and organic solvents, such as mixtures containing alcohols or mixtures containing various organic solvents. Suitable solvents are known to the person skilled in the art. In particular, the final solution containing tartaric acid or tartaric acid tartrates may be an aqueous solution. wet:

The wetting of the wood particles or solid wood parts with a solution containing tartaric acid and / or tartaric acid tartrates can be carried out by any method known to those skilled in the art, which is suitable for contacting the wood particles or solid wood parts with the solution containing tartaric acid and / or tartaric acid tartrate. Suitable methods are e.g. Treating, spraying, coating, dipping or other methods of applying the solution (for example, in the case of MDF production also adding during cooking). The addition of tartaric acid and / or tartaric acid tartrate can also be done together with the glue.

Tartaric acid and / or tartaric acid tartrate:

The term "tartaric acid and / or tartaric acid tartrate" means a compound consisting of or containing tartaric acid having the empirical formula C ₄ H ₆ _O , also referred to as 2,3-dihydroxysuccinic acid or 2,3-dihydroxybutanedioic acid In particular, the salts and esters of tartaric acid, also called tartrates of tartaric acid, include the D - (-) -, as well as the L - (+) form, the meso form of tartaric acid or mixtures thereof, in particular their racemates, such as In particular, the term "tartaric acid esters" in their alcohol part has a branched or unbranched, saturated or mono- or polyunsaturated alkyl having a carbon chain length of from C1 to C12, particularly preferably from C1 to C8 , most preferably from C1 to C4.

Tartaric acid and / or tartaric acid tartrates are preferably used in concentrations of 200 mg / kg to 3 g / kg of wood to be treated or of 10 mg / L to 100 g / L of solution. In particular, the solution according to the invention may contain tartaric acid and / or tartaric acid tartrates in a concentration of <10 g / l, preferably <6 g / l.

The solution containing tartaric acid and / or tartaric acid tartrates may contain at least one further antioxidant or another preservative. Suitable further antioxidants and preservatives are given below: According to Appendix 7 of the Addendum Authorization Regulation (ZZuIV):

- "Preservatives" Substances that prolong the shelf life of foods by protecting them from the harmful effects of micro-organisms.

- "Antioxidants" Substances that prolong the shelf life of foods by protecting them from the harmful effects of oxidation, such as rancidity of fat and color changes.

The above groups also include enzyme inhibitors. According to the invention, it is preferable to use the preservatives and antioxidants which are permitted in the additive approval regulation and in the cosmetics regulation. Substances not listed there also come into question for the uses and products according to the invention, for example 4-hexylresorcinol, NTA (nitrilotriacetate, nitrilotriacetic acid), as well as naturally occurring antioxidants in foods.

Preferred preservatives and antioxidants are those in the version of the additive approval (ZZuIV) in the version valid at the filing date, in particular in their Appendices 4 and 5, and in the Cosmetics Ordinance in the version valid at the filing date, in particular in Appendix 6 thereof ,

Valid versions of the ZZuIV and the Kosmetikverordnung i.S. this application are:

- Regulation on the authorization of additives to foods for technological purposes (Addi- tive Authorization Regulation - ZZuIV) of 29 January 1998

(BGBI I p. 231), as amended by the 1st Regulation amending additives legislation of 13.1.2000 (BGBI I p. 1520), Regulation amending additives legislation and other foodstuffs ordinances of 20. 12. 2002 (BGBI. I p 4695) ^** ), Regulation on fruit juice, some similar products and fruit nectars (Fruit Juice Regulation) of 24 May 2004 (BGBI I p. 1016) ^*** ), Article 1 of the Regulation amending the Additives Marketing Authorization Regulation and other food-law regulations of 20. 1. 2005 (BGBI. I p. 128) ^**** ), Art. 2 § 3 of the G for the reorganization of the food and feed law of 1. 9. 2005 (BGBI 2618) 1) 2) and Art. 2 of the Regulation on amending the food and tobacco law provisions of 22 February 2006 (BGBI I p.

- Cosmetics Ordinance, new version of 7 October 1997 (BGBI I p. 2410), amended by 27. ÄndVO of 19. 12. 1997 (BGBI. I p. 3314) 2), V amending the amending cosmetics regulations of 25 6, 1998 (BGBI., I, p. 1622) 3), 28th Amendment to the Dec. 18, 1998 (BGBl., I, p. 3773), 29th Amendment, 14. 6. 2000, BGBl. I, p. 4), 30. ÄndV of 21. 12. 2000 (BGBI., I, No. 57, pp. 1848), Amendments to 9. 1. 1. 2001 (BGBI., I, p. 3030), Art. 11 §1 1 of the G for the reorganization of the health consumer protection and the food safety of 6. 8. 2002 (BGBI.I. P. 3082), 32. ÄndVO of 28. 3. 2003 (BGBI.I P. 443) 5), 33. ÄndVO vom 23.4.2003 (Federal Gazette No. 79 of 26. 4. 2003, p. 8997) 6), Art. 2 of the Regulation amending the EC TSE Exception Regulation and the 33rd Regulation amending the Cosmetics Ordinance of 29. 9.2003 (BGBI I p. 1951), Art. 7 of the Act amending the Meat Hygiene Act, the Poultry Meat Hygiene Act, the Foodstuffs and Consumer Goods Act Ständegesetzes and other regulations of 13. 5. 2004 (BGBI I p. 934) 7), Art. 1 of the VO amending the Cosmetics Ordinance and amending further foodstuffs legislation of 6. 10. 2004 (BGBI. 2580) 8), Article 1 of the 35th Regulation amending the KosmetikVO of 20 December 2004 (BGBI I, 3569) 9), Article 1 of the 36th Regulation amending the Kosmetik-VO of 18.2.2005 (BGBI., I, p. 120), Art. 5 of the 4th Regulation amending the Food Labeling Ordinance and other foodstuffs ordinances of 18.5.2005 (BGBI. I p. 1401) 10), 37. VO to the Amend the Cosmetics Regulation of 30. 6. 2005 (BGBI I p. 2019) 1 1), Art. 2 of the VO amending the consumer goods Regulation and the Cosmetics Regulation of 13. 7. 2005 (BGBI. I p 2159) 12) and 38. VO amending the Cosmetics Regulation of 13. 12. 2005 (BGBI. I P. 3479) 13).

Some of the other particularly effective antioxidants or preservatives are listed below.

From Annex 4 of the ZZuIV:

(E 170) calcium carbonate, (E 260) acetic acid, (E 261) potassium acetate, (E 262) sodium acetate, sodium acetate, sodium diacetate, (E 263) calcium acetate, (E 270) lactic acid, (E 296) malic acid, (E 300) Ascorbic acid, (E 301) sodium ascorbate, (E 302) calcium ascorbate, (E 304) fatty acid esters of ascorbic acid, ascorbyl palmitate, ascorbyl stearate, (E 306) strong tocopherol-containing extracts, (E 307) alpha-tocopherol, (E 308) gamma-tocopherol, (E 309) delta tocopherol, (E 322) lecithin, (E 325) sodium lactate, (E 326) potassium lactate, (E 327) calcium lactate, (E 330) citric acid, (E 331) sodium citrate, monosodium citrate, disodium citrate, trisodium citrate, (E 332) potassium citrate, monocalcium citrate, tripotassium citrate, (E 333) calcium citrate, monocalcium citrate, dicalcium citrate, tricalcium citrate, (E 334) L (+) - tartaric acid, (E 335) sodium tartrate, mononatrium tartrate, disodium tartrate, (E 336) potassium tartrate , Monocalcium tartrate, dipotassium tartrate, (E 337) potassium sodium tartrate, (E 350) sodium malate, sodium mmalate, sodium hydrogen malate, (E 351) potassium malate, (E 352) calcium malate, calcium malate, calcium hydrogen malate, (E 354) calcium tartrate, (E 380) triammonium citrate, (E 400) alginic acid, (E 401) sodium alginate, (E 402) Potassium alginate, (E 403) ammonium alginate, (E 404) calcium alginate, (E 472a) acetic acid esters of mono- and diglycerides of fatty acids, (E 472b) lactic acid esters of mono- and

Diglycerides of fatty acids, (E 472c) Citric acid esters of mono- and diglycerides of fatty acids, (E 472d) Tartaric acid esters of mono- and diglycerides of fatty acids, (E 472e) Mono- and diacetyl tartaric acid esters of mono- and diglycerides of fatty acids, (E 472f) Mixed Tartaric and acetic acid esters of mono- and diglycerides of fatty acids, (E 500) Sodium carbonates, Sodium carbonate, Sodium hydrogencarbonate, Sesquicarbonate, (E 501) Potassium carbonate, Potassium carbonate, Potassium bicarbonate, (E 503) Ammonium carbonates, ammonium carbonate, ammonium bicarbonate, (E 504) magnesium carbonate, magnesium carbonate, magnesium hydroxide carbonate, magnesium hydrogencarbonate, (E 507) hydrochloric acid, (E 508) potassium chloride, (E 509) calcium chloride, (E 51 1) magnesium chloride, (E 513) sulfuric acid , (E 514) sodium sulfates, sodium sulfate, sodium bisulfate, (E 515) potassium sulfates, potassium sulfate, potassium bisulfate, (E 516) calcium sulfate, (E 524) sodium hydroxide, (E 525) potassium hydroxide, (E 526) calcium hydroxide, (E 527) ammonium hydroxide , (E 528) magnesium hydroxide, (E 529) calcium oxide, (E 530) magnesium oxide, (E 570) fatty acids, (E 574) gluconic acid, (E 575) glucono-delta-lactone, (E 576) sodium gluconate, (E 577 ) Potassium gluconate, (E 578) calcium gluconate.

From Annex 5 of the ZZuIV:

(E 200) sorbic acid, (E 202) potassium sorbate, (E 203) calcium sorbate, (E 210) benzoic acid, (E 211) sodium benzoate, (E 212) potassium benzoate, (E 213) calcium benzoate, (E 214) ethyl-p hydroxybenzoate, (E 215) sodium ethyl p-hydroxybenzoate, (E 216) propyl p-hydroxybenzoate, (E 217) sodium propyl p-hydroxybenzoate, (E 218) methyl p-hydroxybenzoate, (E 219) sodium methyl p-hydroxybenzoate, (E 220) sulfur dioxide, (E 221) sodium sulfite, (E 222) sodium hydrosulfite, (E 223) sodium metabisulfite, (E 224) potassium metabisulfite, (E 226) calcium sulfite, (E 227) calcium bisulfite, (E 228) Potassium bisulfite, (E 249) potassium nitrite, (E 250) sodium nitrite, nitrite pickling salt, (E 251) sodium nitrate, (E 252) potassium nitrate, (E 231) othopenylphenol, (E 232) sodium orthophenylphenol, (E 234) nisin, (E 235) natamycin, (E 239) hexamethylenetetramine, (E 280) propionic acid, (E 281) sodium propionate, (E 282) calcium propionate, (E 283) potassium propionate, (E 284) boric acid, (E 285) sodium tetraborate, (borax) as boric acid; (E 1 105) lysozyme, (E 310) propyl gallate, (E 311) octyl gallate, (E 312) dodecyl gallate, (E 320) butyl hydroxyanisole (BHA), (E 321) butyl hydroxytoluene (BHT), (E 315) isoascorbic acid, ( E 316) sodium isoascorbate, (E 310) propyl gallate, (E 31 1) octyl gallate, (E 312) dodecyl gallate, (E 320) butyl hydroxyanisole.

From Annex 6 of the KosmetikV:

Benzoic acid, its salts and esters, propionic acid and its salts, salicylic acid and its salts, 4

2,4-hexadienoic acid (sorbic acid) and its salts, 5 formaldehyde and paraformaldehyde, 2-hydroxybiphenyl (o-phenylphenol) and its salts, phenol, 2-zinc bis (2-thiolato-pyridine-1-oxide), (zinc pyrithione ), Inorganic sulfites and bisulfites, unbound SO ₂ , sodium iodate, chlorobutanol, 4-hydroxybenzoic acid, its salts and esters, 4-hydroxybenzoic acid benzyl ester, 3-acetyl-6-methyl-2,4 (3H) -pyran-dione (dehydroacetic acid and its salts, formic acid and its sodium salt, 1, 6-bis (4-amidino-2-bromophenoxy) -n-hexane (dibromohexamide) and its salts (including isethionate), ethylmercury (II) thiosalicylic acid, Sodium salt (thiomersalum), phenylmercury and its salts (incl. Borate) compounds, Undecylenic acid and its salts, 5-amino-1,3-bis (2-ethylhexyl) -5-methyl-hexahydropyrimidine, (hexetidine), 5-bromo-5-nitro-1,3-dioxane, 2-bromo-2- nitro-1,3-propanediol (Bronopol), 2,4-dichlorobenzyl alcohol, N- (4-chlorophenyl) -N '- (3,4-dichloro-phenyl) -urea 3-3'-4-4'-tetra - (triclocarbanum), (chloroazobenzene and 3-3'-4-4'-tetrachloroazoxybenzene, 4-chloro-m-cresol, 2,4,4'-trichloro-2'-hydroxy-diphenyl ether, (triclosanum), 4-chloro-3,5-dimethylphenol, 1, 1 '-

Methylenebis [3- (1-hydroxy-methyl-2,5-dioximidazolidin-4-yl) urea], (imidazolidinylurea), poly (hexamethylenediguanide) hydrochloride, 2-phenoxy-ethanol, hexamethylenetetramine (methenamine), 1 - (3-chloroallyl) -3,5,7-triaza-1 -azonia-adamantane chloride, 1- (4-chlorophenoxy) -1- (imidazol-1-yl) -3,3-dimethyl-2-butanone, 1, 3-bis- (hydroxy-methyl) -5,5-dimethyl-2,4-imidazolidinedione, benzyl alcohol, 1-hydroxy-4-methyl-6- (2,4,4-trimethylpentyl) -2-pyridone,

Monoethanolamine salt, 1,2-dibromo-2,4-dicyanobutane, 2,2'-methylenebis (6-bromo-4-chlorophenol), bromochlorophene, 3-methyl-4- (1-methylethyl) phenol, 2 Benzyl 4-chlorophenol, chlorophenum, 2-chloroacetamide, chlorhexidine, its acetate, gluconate and hydrochloride, 1-phenoxy-1-propan-2-ol, 4 N-alkyl (C12-C22) trimethylammonium bromide and chloride, 4.4 -Dimethyl-1,3-geoxazolidine, N-hydroxymethyl-N- [1,3-di (hydroxymethyl) -2,5-dioxoimidazolidin-4-yl] -N'-hydroxymethylurea, 1,6-bis (4-amidino-phe-noxy) -n-hexane (hexamidine) and its salts, including isethionate and p-hydroxybenzoate, glutaraldehyde (pentane-1, 5-dial), 5-ethyl-1-aza-3,7- dioxabicyclo- [3.3.0] octane, 3- (4-chlorophenoxy) -1,2-propanidol (chlorphenesin), sodium hydroxymethylaminoacetate, silver chloride, benzethonium chloride, benzalkonium chloride, bromide and saccharinate, benzalkonium chloride, benzylhemiformal, 3 iodo-2-propynyl-butylcarbamate, 2-methyl-3 (2H) -isothiazolone.

Very particularly preferred further antioxidants and / or preservatives are selected from the group comprising BHA (E320), BHT (E321), citric acid (E330), EDTA (E385), lauryl gallate (Gallate E310 to E312), octyl gallate (E31 1), and their salts and esters.

The antioxidants and / or preservatives are preferably used in the concentrations permitted by law in the Food and Cosmetic Additives Ordinance. The antioxidants and / or preservatives are very particularly preferably used in concentrations of 200 mg / kg to 3 g / kg of wood or of 10 mg / L to 100 g / L of solution. The at least one further antioxidant or the at least one further preservative is preferably present in a concentration of <10 g / l, preferably <6 g / l, very particularly preferably <3 g / l.

In particular, citric acid and / or citric acid tartrates can be used as at least one further antioxidant or at least one further preservative. The ratio of tartaric acid and / or tartaric acid tartrates to a further antioxidant or preservative in a solution according to the invention can be selected from a range from 10: 1 to 1:10, preferably from 5: 1 to 1: 5. The ratio is particularly preferably 1: 1.

The solution according to the invention may in particular contain tartaric acid and / or tartaric acid tartrates and citric acid and / or citric acid tartrates in equal concentration proportions, preferably in each case in a concentration of <6 g / l, more preferably of <3 g / l each.

According to the invention, at least one or more different preservatives, antioxidants and combinations thereof can be used in one solution or in different solutions, in a single step or in several, different process steps, at one or more points in the process according to the invention.

An embodiment of the process according to the invention for the production of wood-containing intermediates for further processing into wood materials, in particular OSB, and solid wood products, comprises the steps: a) use of wood-containing starting materials, b) wetting the wood-containing starting materials with a solution containing tartaric acid and / or tartaric acid tartrates.

A preferred embodiment of the process according to the invention for the production of wood-containing intermediates for further processing into wood materials, in particular OSB, and solid wood products, comprises the steps: a) use of wood particles or solid wood parts, b) wetting the wood particles or solid wood parts with a further solution containing tartaric acid and or tartaric acid tartrate, wherein the solution may contain other ingredients, such as an adhesive.

The wood-containing starting materials, preferably wood particles and / or solid wood parts, wetted with a solution comprising tartaric acid and / or tartaric acid tartrate, may optionally be subjected to a drying step before and / or after wetting with the solution according to the invention. A process which is particularly suitable for the production of wood-containing intermediates for further processing into wood materials, in particular OSB, comprises the steps: a) use of wood particles, optionally dried, b) wetting of the wood particles with a solution containing tartaric acid and / or tartaric acid tartrates and at least one adhesive, c) pressing the wetted wood particles.

In a process for the production of wood-containing intermediates for further processing into wood-based materials, in particular OSB boards, wetting with a solution containing tartaric acid and / or tartaric tartrate both before drying the wood particles, and only after drying or at another appropriate time take place in the process, the solution may then optionally contain other ingredients, such as at least one suitable adhesive. The process according to the invention also comprises processes in which, both before drying the wood particles, wetting with a solution containing tartaric acid and / or tartaric acid tartrate takes place, as well as after drying or at another suitable time in the process, e.g. before gluing or together with gluing using a solution containing both tartaric acid and / or tartaric acid tartrates, as well as optionally other ingredients, e.g. contains at least one adhesive. In this case, identical or different further preservatives, antioxidants or combinations thereof may be contained in the two solutions, preferably citric acid and / or salts or esters thereof.

A preferred process for the preparation of wood-containing intermediates for further processing into wood-based materials, in particular OSB, comprises the steps of: a) using wood particles, b) wetting the wood particles with a solution containing tartaric acid and / or tartaric acid tartrates, c) drying the product from step b), d) wetting the product from step c) with a solution containing tartaric acid and / or tartaric acid tartrates and / or other preservatives and / or antioxidants and at least one adhesive, e) pressing the product from step d).

The inventive methods are not limited to wood of a particular type of wood. Also, different woods can be processed together in a process as mixed or separate wood particles or solid wood parts. The process is particularly suitable for the production of wood-containing intermediates containing softwood.

The process according to the invention is very particularly suitable for the production of wood-containing intermediates containing pinewood, preferably Pinus sylvestris.

The invention further provides wood-containing intermediates for further processing into wood-based materials, in particular OSB, and solid wood products, which are characterized in that the wood-containing starting materials were wetted with a solution containing tartaric acid and / or tartaric acid tartrate.

The invention also relates to wood-based materials, preferably OSB boards, and solid wood products, which are characterized in that the wood materials or solid wood products contain wood-containing starting materials which have been wetted with a solution containing tartaric acid and / or Tartarate tartrates or wood-containing intermediates prepared by any of the invention Processes are made.

The tartaric acid and / or tartaric acid tartrates can be used to prepare the wood-containing intermediates according to the invention.

Tartaric acid and / or tartaric acid tartrates can be used in a process according to the invention for the production of wood-containing intermediates.

In the above uses and methods, the following further preservatives and antioxidants are preferably used, either as a single antioxidant or as a single preservative or in combination of several different preservatives and / or antioxidants: BHA (E320), BHT (E321), citric acid (E330) , EDTA (E385), lauryl gallate (Gallate E310 to E312), octyl gallate (E31 1) and / or their salts or esters. A preferred combination of preservatives and antioxidants contains tartaric acid and citric acid. EXAMPLES

Example 1: Evaluation of the experiments with strands with regard to the effectiveness of added substances in the μ-Chamber

Concentrations of the solutions in the beaches

For subsequent experiments and investigations with subsequent analyzes, solutions of selected compounds in water were prepared. The selected and used concentrations and mixtures of compounds are shown in Table 1. In this case, sodium citrate and octyl gallate were used in the concentrations as in the patent application WO 2006/032267 A1. Octyl gallate is not a solution but a dispersion.

Table 1: Concentrations of the solutions in the examples

Fresh strands were individually dipped in the above solutions of tartaric acid / citric acid (W / C), tartaric acid (W), citric acid (C), sodium citrate (NaC) and a dispersion of octyl gallate (O) at the concentrations shown in Table 1, and then dried in a muffle furnace at 400 ⁰ C. The substances were used individually and / or as a mixture as described in Table 1. For comparison, untreated (treated with water) strands were dried in a muffle furnace at 400 ⁰ C. After drying, the strands were introduced into the μ-chamber and the VOC emission determined. The results are shown in Table 2.

Table 2: Strands treated with water, W / C, W, C, NaC and O.

It is clearly evident that both the mixture of tartaric and citric acid and tartaric acid alone significantly more effectively suppress aldehyde formation than sodium citrate and octyl gallate. This effect is all the more surprising, since sodium citrate and octyl gallate were used in significantly higher concentrations than tartaric acid or the tartaric acid / citric acid mixture. The suppression of aldehyde formation is attributable to the concentration differences of pentanal, hexanal, heptanal, octanal and nonanal. In addition, the release of terpenes by solutions containing tartaric acid is drastically lower. In particular, it has been shown that the use of tartaric acid, both alone and in admixture with citric acid, has an advantage in the range of the octanal compared to sodium citrate and octyl gallate. Compared to sodium citrate, tartaric acid, alone or mixed with citric acid, has clear advantages over all aldehydes (pentanal, hexanal, heptanal, octanal and nonanal). Compared to octyl gallate, tartaric acid alone or mixed with citric acid has distinct advantages in the emission of alpha-pinene, beta-pinene and 3-carene, as well as a measurable advantage in the emission of the octanal aldehyde. The superiority of tartaric acid can be further increased by using instead of tartaric acid alone a mixture of tartaric acid and citric acid. The mixture of tartaric acid and citric acid shows in all investigated parameters a measurable advantage over tartaric acid alone.

Example 2: Comparison of emission levels of OSB prepared from treated or untreated strands

8.5 kg of fresh strands were sprayed with 1 liter of aqueous solution of 3 g / L tartaric acid and 3 g / L citric acid within 10 minutes (100 ml / min) in a gluing drum. The strands were then dried at 250 ⁰ C and 400 ⁰ C in a drum dryer. After the loan to value of dried mung Strands the production of OSB panels was carried out at a press temperature of 220 ⁰ C (pressing time factor 15). Four OSB plates treated with preservatives were prepared and, for comparison, OSB plate was prepared without the addition of preservatives (water only). A total of five OSB boards were produced and tested.

After fabrication, the plates were placed in emission test chambers and VOC emission measured over a period of up to 49 days. The results are shown in Table 3.

Table 3: Hexanal emission in [μg / m ³ ] from OSB treated with water or with W / C, dried at 250 and 400 ⁰ C over time in days

This showed a significantly lower emission of aldehydes from the treated plates than from the untreated plate (reduction by% to Vz of the comparative sample). The Hexanalemissionen treated with tartaric acid and citric acid OSB (W / C) are from the third day significantly lower than that of the comparative plate (water, 250 ⁰ C). The treated plates also have a higher concentration of aldehydes at no later time point. Thus, it is clearly evident that the treatment with a mixture of tartaric and citric acid is not a time delay of the aldehyde emissions.

Example 3: Comparison of untreated and treated strands

In this experiment, the strands were prepared in the pilot plant in an industrial comparable plant from the pine logs and in the Beleimtrommel which is usually used for gluing, sprayed with the solutions containing a mixture of tartaric and citric acid with the concentration of Table 1. The technological parameters are the same as in the OSB plate production and specified there under the experimental procedure. The beaches were then dried in a drum dryer at 250 ^° C. or at 400 ^° C. This was followed by examination and analysis in the laboratory. The results are shown in Table 4. Table 4: Industrial strands untreated, treated with water or with W / C, dried at 250 and 400 ⁰ C untreated; Water, W / C, W / C, not dried by dried by drying at 25O ⁰ C 25O ⁰ C 400 ⁰ C.

Hexanal 415 38 8

These results confirm that even with a reduction in the industry Strands Aldehydemission is achieved both at a drying at 250 ⁰ C and at 400 ° C by using a mixture of tartaric and citric acid.

Example 4: Evidence of Reduction of Aldehyde Emission on Strands Obtained from Spruce

Fresh spruce strands were individually dipped in the abovementioned solutions of tartaric acid / citric acid (W / C), tartaric acid (W), citric acid (C) with the concentrations given in Table 1 and then dried in a muffle furnace at 400 ^° C. , The substances were used individually and / or as a mixture as described in Table 1. For comparison, only treated with water (untreated) spruce strands were dried in a muffle furnace at 400 ° C. After drying, the spruce strands were introduced into the μ-chamber and the VOC emission determined. The hexanal emission of the spruce strands are summarized in Table 5.

Table 5: hexanal emission in [g / m ^3]

Even with spruce wood, the low hexanal emission could be completely reduced individually by treating with a mixture of tartaric acid and citric acid and the solutions of each citric or citric acid.

Claims

claims

1. A process for the preparation of wood-containing intermediates for further processing into wood materials, in particular OSB, and solid wood products, comprising the steps: a) use of wood-containing starting materials, b) wetting the wood-containing starting materials with a solution containing tartaric acid and / or tartaric acid tartrates.

2. The method according to claim 1 for the production of wood-containing starting materials for further processing into wood materials, in particular OSB, comprising the steps: a) use of wood particles, b) wetting of the wood particles with a solution containing tartaric acid and / or

Tartaric acid tartrate and at least one adhesive, c) pressing the wetted wood particles.

3. The method according to claim 2, comprising the steps of: a) using wood particles, b) wetting the wood particles with a solution containing tartaric acid and / or tartaric acid tartrates, c) drying the product from step b), d) wetting the product from step c ) with a solution containing tartaric acid and / or tartaric acid tartrates and / or other preservatives and / or antioxidants and at least one adhesive, e) pressing the product from step d).

4. The method according to any one of the preceding claims, characterized in that the solution is an aqueous solution.

5. The method according to any one of the preceding claims, characterized in that the solution contains tartaric acid and / or tartaric acid tartrates in a concentration of <10 g / l, preferably <6 g / l.

6. The method according to any one of the preceding claims, characterized in that the solution contains at least one further antioxidant or at least one further preservative.

7. The method according to claim 6, characterized in that the at least one further antioxidant or the at least one further preservative in a concentration of <10 g / l, preferably <6 g / l is present.

8. The method according to any one of claims 6 to 7, characterized in that the at least one further antioxidant or the at least one further preservative

Citric acid and / or salts or esters thereof.

9. The method according to any one of claims 6 to 8, characterized in that the solution contains tartaric acid and / or tartrates and citric acid and / or salts or esters thereof in equal concentration proportions, in each case in a concentration of <6 g / l, preferably from each <3 g / l.

10. The method according to any one of the preceding claims, characterized in that the wood-containing starting materials containing softwood, especially pine, preferably from Pinus sylvestris.

1 1. Wood-containing intermediates for further processing into wood materials, in particular OSB, and solid wood products, characterized in that the wood-containing starting materials have been treated with a solution containing tartaric acid and / or tartaric acid tartrates.

12. wood materials, esp. OSB, characterized in that the wood materials contain wood-containing intermediates according to claim 11.

13. OSB, characterized in that these OSB contain wood-containing intermediates according to claim 1 1.

14. Solid wood products, characterized in that the solid wood products wood-containing

Intermediates according to claim 11 included.

15. Use of tartaric acid and / or tartrates for the production of wood-containing intermediates.

16. Use of a solution containing tartaric acid and / or tartaric acid tartrates and citric acid and / or salts or esters thereof for the production of wood-containing intermediates.