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EP-4735551-A1 - SUGAR-CONTANING BINDER COMPOSITION FOR WOOD MATERIAL BOARDS, IN PARTICULAR WOOD PARTICLE BOARDS, IN THE FORM OF A ONE-COMPONENT SYSTEM

EP4735551A1EP 4735551 A1EP4735551 A1EP 4735551A1EP-4735551-A1

Abstract

The present invention relates to a binder composition for wood material boards, as in the form of a one-component system, the binder composition comprising a) at least one sugar, and b) at least one mixture composed of at least one compound of general formula (I) R 1 a SiX 1 (4-a) (I), wherein X 1 is alkoxy, aryloxy, acyloxy, and R 1 is an organic moiety selected from the group comprising alkyl, aryl, cycloalkyl, which can be interrupted by -O- or -NH-, and wherein R 1 comprises at least one functional group Q 1 , which is selected from a group containing an acryl group, an acryloxy group, an amino group, an aminoalkylamino group, a methacryl group, a methacryloxy group, a cyano group, an isocyano group, an epoxide group, and an alkenyl group, and a is 0, 1, 2, 3, in particular 0 or 1, at least one compound of general formula (II) R 2 b SiX 2 (4-b) (II), wherein X 2 is alkoxy, aryloxy, acyloxy, R 2 is a non-hydrolyzable organic moiety R2 selected from the group comprising alkyl and aryl, and b is 1, 2, 3, or 4, preferably 1 or 2.

Inventors

  • GIER, ANDREAS
  • KALWA, NORBERT

Assignees

  • SWISS KRONO Tec AG

Dates

Publication Date
20260506
Application Date
20240625

Claims (15)

  1. 1. Binder composition for wood-based panels, in particular wood chipboards, as a one-component system comprising a) at least one sugar; and b) at least one mixture of at least one compound of the general formula (I) R 1 aSiX 1 (4 -a) (I), where - X 1 is alkoxy, aryloxy, acyloxy, and - R 1 is an organic radical selected from the group comprising alkyl, aryl, cycloalkyl, which may be interrupted by -O- or -NH-, and - wherein R 1 has at least one functional group Qi which is selected from a group containing an acrylic, acryloxy, amino, aminoalkylamino, methacrylic, methacryloxy, cyano, isocyano, epoxide and alkenyl group, and - a = 0, 1, 2, 3, in particular 0 or 1, - at least one compound of the general formula (II) R 2 bSiX 2 ( 4 .b) (II), where - X 2 is alkoxy, aryloxy, acyloxy, - R 2 is a non-hydrolyzable organic radical R 2 is selected from the group comprising alkyl and aryl, and - b = 1, 2, 3, or 4, preferably 1 or 2.
  2. 2. Binder composition according to claim 1, characterized in that it is free from formaldehyde, synthetic polyols and/or plastics.
  3. 3. Binder composition according to one of the preceding claims, characterized in that the at least one sugar is a mono- or disaccharide, preferably sucrose.
  4. 4. Binder composition according to one of the preceding claims, characterized in that at least two, preferably at least three silane compounds of the general formula (I) and at least one compound of the general formula (II) are contained.
  5. 5. Binder composition according to one of the preceding claims, characterized in that X 1 and X 2 are selected from a group containing C 1-6 alkoxy, in particular methoxy, ethoxy, n-propoxy and butoxy, C 1-6 aryloxy, in particular phenoxy, C 2-7 acyloxy, in particular acetoxy or propionoxy.
  6. 6. Binder composition according to one of the preceding claims, characterized in that R 1 is selected from a group comprising C 1 -C 6 -alkyl, in particular C 1 -C 25 -alkyl, C 1 -C 6 -alkyl, and C 8 -C 8 -cycloalkyl.
  7. 7. Binder composition according to one of the preceding claims, characterized in that the at least one functional group Q 1 is selected from a group containing amino, aminoalkylamino, cyano, isocyano, epoxide and alkenyl groups, preferably amino, aminoalkylamino, epoxide and alkenyl groups, particularly preferably amino, aminoalkylamino and alkenyl groups.
  8. 8. Binder composition according to one of the preceding claims, characterized in that at least one compound of the general formula (I) corresponds to the formula R 1 SiX 1 3 with R 1 being C1-C10 alkyl with a functional group Q 1 selected from amino, aminoalkylamino, cyano, isocyano, epoxide and alkenyl groups and with X 1 being alkoxy, in particular methoxy, ethoxy, n-propoxy or i-propoxy.
  9. 9. Binder composition according to one of the preceding claims, characterized in that at least one compound of the general formula (I) corresponds to the formula SiX 1 4, in particular with X 1 alkoxy, in particular methoxy, ethoxy, n-propoxy or i-propoxy.
  10. 10. Binder composition according to one of the preceding claims, characterized in that the non-hydrolyzable organic R 2 is selected from a group comprising Ci-Cis-alkyl, in particular Ci-C alkyl, and Ce-C aryl, preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, cyclohexyl, phenyl and naphthyl.
  11. 11. Binder composition according to one of the preceding claims, characterized in that at least one compound of the formula (II) corresponds to the formula R 2 SiX 2 3 with R 2 as a C1 -C10 alkyl group, preferably methyl, ethyl, propyl, pentyl, hexyl, heptyl, octyl, or as a C6-C10 aryl group, preferably phenyl, and with X 2 as alkoxy, in particular methoxy, ethoxy, n-propoxy or i-propoxy.
  12. 12. Binder composition according to one of the preceding claims, characterized in that inorganic particles, in particular SiO2, Al2O3, ZrO2, TiO2 particles, can be included.
  13. 13. Binder composition according to one of the preceding claims, characterized by at least one thickener.
  14. 14. Wood-based panel comprising at least one binder system according to one of the preceding claims.
  15. 15. Wood-based panel according to claim 14, characterized in that it is a wood chipboard with a transverse tensile strength of greater than 0.2 N/mm 2 , preferably greater than 0.25 N/mm 2 , particularly preferably greater than 0.3 N/mm 2 , even more preferably greater than 0.4 N/mm 2 .

Description

Sugar-containing binder composition for wood-based panels, in particular particle boards, as a one-component system The present invention relates to a sugar-containing binder system for wood-based panels, and to a wood-based panel containing this sugar-containing binder system. Description Adhesives and binding agents are a crucial component in the industrial production of a wide range of products, including the manufacture of wood-based panels. Wood shredded products are glued with the binding agent and pressed into shaped bodies such as panels using pressure and temperature. The type and quantity of binding agent used is significantly influenced by the size and quality of the wood fibers and/or wood chips used. Wood materials (HWS) have been manufactured for decades using binders based on thermosets. Of these thermosets, urea-formaldehyde glues are the most important in terms of quantity. Other glues also used in wood materials are melamine-urea-formaldehyde and phenol-formaldehyde glues. These binders essentially contain two components. One component is formaldehyde, the other component is a chemical based on petroleum (e.g. phenol) or from ammonia chemistry (e.g. melamine or urea). In recent years, however, toxicological studies have shown that formaldehyde is to be classified as carcinogenic. This naturally also affects products such as wood materials, which emit small amounts of formaldehyde during use due to the use of the above-mentioned glue. There are also glues based on isocyanates (PMDI = polymeric diphenylmethane diisocyanate). All of these glues are made from petrochemical precursors. The developments at EU level show that, in addition to the requirements regarding the circular economy, there is also an increased focus on the use of renewable raw materials for the manufacture of products. The glues mentioned above and the HWS made from them therefore have problems. On the one hand, recycling HWS made with thermosetting binders is difficult because the glues used for Part must have a high hydrolysis resistance and of course the use of petrochemical precursors should be avoided. In addition, the requirements regarding the emission of ingredients, especially formaldehyde, are currently becoming more stringent, which does not necessarily encourage the use of HWS with formaldehyde-containing glues. One possible solution is to use glues based on renewable raw materials. Possible precursors include mono- or disaccharides, starch, proteins, lignin, to name just a few. The binder composition described in EP 2930195 A1 is based on a mono- and/or disaccharide, an amide and an aldehyde, in particular formaldehyde. Although the proportion of formaldehyde could be reduced, a complete elimination of formaldehyde is not possible with this system. EP351 1353 A1 discloses a binder composition comprising a mono- and/or disaccharide, an amide and a dialdehyde, whereby a stable precursor is first produced from the saccharide and urea as an amide. The dialdehyde is added to this precursor shortly before use as a binder. EP 3995538 A1 and EP 4129597 A1 describe two-component binder systems for wood-based panels based on sugar or sugar alcohols and isocyanate and possibly polyvinyl alcohol. EP 2576661 A1 describes a two-component system consisting of a plant flour and a polyisocyanate-based prepolymer or latex. Another system based on lignin, alkali and epichlorohydrin is disclosed in WO 2022003614. This system is used to produce plywood. In each of the systems described, a hardener or crosslinker is described, which makes the system technically usable in the first place. The hardeners or crosslinkers are usually based on "petroleum chemicals", so the approach of developing a binder system based only on renewable raw materials is not fulfilled. In addition, the hardeners or crosslinkers sometimes have to be added in considerable quantities. Another aspect is that these binders are not suitable for the production of the various wood materials, but only for one or a few HWS. However, a binder system should enable the production of "all" wood materials. Adhesive systems with plant components are also known. CN 106398614 describes a process for producing a spray adhesive for application to the surface of a wooden article. The adhesive composition described here is based on epoxy resins, MQ silicone resin (M: MesSiO; Q: SiO4), organic solvents (such as acetone, cyclohexane), EDTA, various plant components such as Echinacea, Magnolia officinalis, Pineilia Chrysanthemum and many others, tea, almond milk, ash, boron carbide, brown sugar and many other components. As part of these changes in the market due to legal requirements, the question always arises as to whether the use of renewable raw materials could lead to food shortages. The question also needs to be answered as to whether the precursors for the production of glues are available in sufficient quantities all year round. In addition, possible glues based on renewa