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EP-4741468-A1 - COMPOSITION AND PROCESS TO PREPARE A LIGNOCELLULOSIC-BASED ARTICLE

EP4741468A1EP 4741468 A1EP4741468 A1EP 4741468A1EP-4741468-A1

Abstract

The present invention relates to a process for preparing a lignocellulosic-based article comprising resinating lignocellulosic material with an adhesive composition comprising a protein, an organic polycarboxylic acid compound, a non-aromatic polyol and water.

Inventors

  • MANGEON PASTORI, Carine
  • PELLETIER, Henri

Assignees

  • EVERTREE

Dates

Publication Date
20260513
Application Date
20241107

Claims (15)

  1. An adhesive composition comprising at least three different components which are a protein, an organic polycarboxylic acid compound and a non-aromatic polyol and optionally water; provided that if said organic polycarboxylic acid compound comprises only two carboxyl functional groups then said polyol comprises at least three hydroxyl functional groups and if said polyol comprises only two hydroxyl functional groups then said organic polycarboxylic acid compound comprises at least three carboxyl functional groups, provided that said adhesive composition is substantially free from an oligoester obtainable by esterification of glycerol and citric acid and provided that if the adhesive composition comprises one or more additional components, then the latter is/are non-aromatic components.
  2. The adhesive composition according to claim 1, wherein the organic polycarboxylic acid compound is selected from the group consisting of succinic acid, tartaric acid, malic acid, oxalic acid, malonic acid, maleic acid, fumaric acid, adipic acid, glutaric acid, suberic acid, isophthalic acid, terephthalic acid, itaconic acid, citric acid, aconitic acid, isocitric acid, oxalosuccinic acid, tricarballylic acid, trimesic acid and a combination thereof, preferably tartaric acid, malic acid, glutaric acid, citric acid and a combination thereof.
  3. The adhesive composition according to claim 1 or 2, wherein the polyol is selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, glycerol monolaurate, propylene glycol, glycerol, polyglycerol, erythritol, threitol, arabitol, xylitol, ribitol, mannitol, sorbitol, galactitol, fucitol, iditol, sucrose, inositol, volemitol, isomalt, maltitol, lactitol, maltotriitol, maltotetraitol, fructose, glucose and a combination thereof, preferably diethylene glycol, triethylene glycol, propylene glycol, glycerol, polyglycerol, sucrose and a combination thereof.
  4. The adhesive composition according to anyone of claims 1 to 3, wherein the protein is selected from the group consisting of ground plant seed, a plant seed meal or flour, a plant protein concentrate and a plant protein isolate.
  5. The adhesive composition according to anyone of claims 1 to 4, wherein it further comprises an additive.
  6. The adhesive composition according to anyone of claims 1 to 5, wherein it comprises at least 2 wt% crude protein, at least 5 wt% non-aromatic polyol and at least 5 wt% organic polycarboxylic acid compound, the percent being by weight relative to the total weight of the adhesive composition.
  7. The adhesive composition according to anyone of claims 1 to 6, wherein it has a viscosity at 20°C and at 1 atm of less than 1000 mPa.s.
  8. The adhesive composition according to anyone of claims 1 to 7, wherein it is a one-part adhesive composition, a two-part adhesive composition or a multi-part adhesive composition.
  9. A process for preparing a lignocellulosic-based article comprising the steps of: a. providing lignocellulosic material and an adhesive composition according to anyone of claims 1 to 8, b. resinating the lignocellulosic material with the adhesive composition, c. curing and optionally pressing the lignocellulosic material impregnated with the adhesive composition, thereby forming the lignocellulosic-based article.
  10. A process according to claim 9, wherein the lignocellulosic-based article is a multi-layer lignocellulosic-based article comprising a core layer and two surface layers, each layer comprising or consisting of lignocellulosic material, comprising: a. providing lignocellulosic material and an adhesive composition according to anyone of claims 1 to 8, b1. resinating the lignocellulosic material forming the core layer, by adding the adhesive composition to a lignocellulosic material, to provide a lignocellulosic material impregnated with the adhesive composition, b2. resinating the lignocellulosic material forming the surface layers, by adding the adhesive composition to a lignocellulosic material, to provide a lignocellulosic material impregnated with the adhesive composition, c1. forming a mat with the lignocellulosic material forming the core layer impregnated with the adhesive composition and the lignocellulosic material forming the two surface layers impregnated with the adhesive composition, and c2. curing the adhesive compositions impregnating the lignocellulosic material forming the core layer and the lignocellulosic material forming the surface layers whereby a multi-layer lignocellulosic-based article comprising a core layer and two surface layers is obtained.
  11. A process according to claim 9, wherein the lignocellulosic-based article is a multi-layer lignocellulosic-based article comprising a core layer and two surface layers, each layer comprising or consisting of lignocellulosic material, comprising: a1 providing lignocellulosic material, a2. providing a first adhesive composition according to anyone of claims 1 to 8, a3. providing a second adhesive different from the first adhesive composition, b1. resinating the lignocellulosic material forming the core layer, by adding the second adhesive composition to a lignocellulosic material, to provide a lignocellulosic material impregnated with the second adhesive composition, b2. resinating the lignocellulosic material forming the surface layers, by adding the first adhesive composition to a lignocellulosic material, to provide a lignocellulosic material impregnated with the first adhesive composition, c1. forming a mat with the lignocellulosic material forming the core layer impregnated with the second adhesive composition and the lignocellulosic material forming the two surface layers impregnated with the first adhesive composition, c2. curing the adhesive compositions impregnating the lignocellulosic material forming the core layer and the lignocellulosic material forming the surface layers whereby a multi-layer lignocellulosic-based article comprising a core layer and two surface layers is obtained.
  12. A process according to claim 11, wherein the second adhesive composition comprises or consists of: - a protein-based adhesive, such as soy flour, - a polyamidoamine-epichlorohydrin (PAE) resin, a PAE-based resin, a polyalkylenepolyamine-epichlorohydrin resin, an itaconic acid-based polyamidoamine-epichlorohydrin resin and/or an amine polymer-epichlorohydrin resin, - an epoxy resin such as bisphenol A diglycidyl ether epoxy resin, - an isocyanate resin and/or isocyanate-based resin, - an urea-formaldehyde (UF) resin, melamine-formaldehyde resin, melamine-urea-formaldehyde (MUF) resin, phenol-formaldehyde resin, resorcinol-formaldehyde resin, other resins based on formaldehyde or on another aldehyde such as furfural, propanal, butyraldehyde, succinaldehyde, glutaraldehyde, dimethoxyethanal, glyoxylic acid, glycolaldehyde, vanillin, - a polyurethane-based resin, - a polyacid-based resin such as based on maleic anhydride or acetic acid, - an acrylate-based or methacrylate-based resin such as poly(methyl methacrylate), ethylene vinyl acetate (EVA), ethylene-co-vinylacetate-co-acrylic acid, ethylene-co-vinylacetate-co-methacrylic acid, ethylene-co-vinylacetate-co-vinylalcohol, carboxylated vinyl acetate-ethylene copolymers, ethylene vinyl alcohol (EVOH), polyvinylalcohol, polyvinylbutyral-co-vinylalcohol, polyvinylacetate-co-vinylalcohol, or - a mixture thereof.
  13. A process according to anyone of claims 9 to 12, wherein the lignocellulosic material includes straw, paper, cardboard, wood flour (or powder) wood sawdust, wood fibers, wood strands (or flakes), wood particles (or chips) or a mixture thereof
  14. A lignocellulosic mat comprising lignocellulosic material impregnated with an adhesive composition according to anyone of claims 1 to 8.
  15. A lignocellulosic-based article obtained by the process according to anyone of claims 9 to 13.

Description

Field of the Invention The present invention relates to an adhesive composition, its uses for preparing a lignocellulosic-based article and to a lignocellulose-based article obtained thereof. The adhesive composition comprises at least three different components which are a protein, an organic polycarboxylic acid compound and a non-aromatic polyol. More specifically, the present invention relates to a process for preparing a multi-layer lignocellulosic article comprising a core (inner) and two surface (outer) layers using this adhesive composition. Background of the Invention Lignocellulosic-based composites comprise a plurality of lignocellulosic materials (e.g., wood, straw) bound together with an adhesive (or resin). Traditionally, these lignocellulosic-based composites are manufactured using an urea formaldehyde (UF) resin, a melamine urea formaldehyde (MUF) resin, a phenol formaldehyde (PF) resin, or a polymeric methylenediphenyl diisocyanate (pMDI) resin; all made from petroleum feedstock. Processes and industrial equipment that can be used to manufacture lignocellulosic-based composites, such as plywood, oriented strand board, particleboard, chipboard fiberboard, are described for example in: Wood-Based Panels - An Introduction for Specialists, COST Office, 2010, Edited by H. Thoemen, M. trie and M. Sernek, Published by Brunel University Press, London, UB8 3PH. England, ISBN 978-1-902316-82-6. In particular, multi-layer lignocellulosic-based articles, such as wood-based composites, include at least one lignocellulosic core (or intermediate) layer sandwiched between two lignocellulosic surface (or face) layers which are at least one upper lignocellulosic surface layer and at least one lower lignocellulosic surface layer. The density and the structure of the lignocellulosic layers can be identical or different. The lignocellulosic layers can respectively be made of identical or different lignocellulosic materials such as straw, paper, cardboard, wood. The orientation of the lignocellulosic materials forming the layers can respectively be identical or different, for example oriented longitudinally or transversely. Also, the size of the lignocellulosic materials forming the layers can respectively be identical or different. The wood particles used in the surface layers have generally a smaller average particle size than wood particles used in the core layer. For example, wood particleboards are manufactured with three different layers; one core layer with large wood particles (average particles width approximately between 1 to 5 mm) representing around 50 to 80% of the panel, and two surface layers, located on each side of the core layer, with smaller wood particles (average particles width approximately below 1 mm) representing 20 to 50% of the panel. Wood particles have an average aspect ratio (length:width) of greater than 1:1. Recent environmental and health concerns highlight the need for more eco-friendly adhesive compositions and for lignocellulosic-based composites with low emissions of volatile organic compounds (VOC). Patent application FR3001461 A1 discloses an adhesive composition having low emissions of volatile organic compounds, useful for preparing a cellulose-based particleboard. This adhesive composition comprises a protein and an oligoester obtainable by esterification of glycerol and citric acid. According to patent application FR3001461 A1, an oligoester is an oligomer with a degree of polymerization (DP) comprised between 1 and 20 and whose units are linked by ester functions. During esterification, the citric acid/glycerol molar ratio is of 1/1 to 10/1. Esterification takes place without the protein. The esterification temperature is comprised between 100°C and 200°C. In the adhesive composition, the proportion by weight relative to the weight of the adhesive of (i) the oligoester is from 60% to 99%, (ii) the protein is from 1% to 20% and (iii) the water is from 1% to 20%. The adhesive composition can further comprise unreacted citric acid and glycerol, but in small quantities. Typically the unreacted glycerol represents less than 5% and in particular less than 2% by weight relative to the weight of the adhesive. Indeed, according to this document one seeks to minimize the presence of glycerol which can have a negative impact during the subsequent preparation of the particle board, because it would promote delamination of the particle board. This adhesive composition does not contain petroleum feedstock; however its method of preparation requires heating the mixture at high temperature, optionally with vacuum, to obtain the oligoester, therefore increasing the production time and costs. Patent application FR3001461 A1 also discloses a process for preparing mono- or multi-layer lignocellulosic-based particleboards using this adhesive composition. Umemura et al. 2013 and 2015 (respectively "Investigation of a new natural adhesive composed of citric acid and sucrose for particleboard"