RU2459850C2 - Adhesive system - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: adhesive system contains an adhesive composition which contains from approximately 5 to approximately 50 wt % albumen and one or more polymers containing acetoacetylated alcohol. The adhesive system further contains one or more polymers which contain polyvinyl amine, polyvinyl formamide, poly (copolymer of vinyl alcohol and vinyl amine), poly(copolymer of vinyl alcohol and vinyl formamide), polyallyl amine, polyethylene imine or polyamidoamine. To obtain a wood-based product, the adhesive system is applied onto one or more fragments of wood-based material, and the fragments are joined with the next one or more fragments of the material. The fragments are wood chips or wood particles. The wood-based product is laminated material, flooring plywood, furniture plywood, multilayer plywood, wall board, roofing panel or glued plank girder or wood, woodchip or fibre board, or oriented strand board.

EFFECT: use of the adhesive system to obtain a wood-based product provides excellent adhesion strength and water-resistance.

17 cl, 3 tbl, 3 ex

Description

The present invention relates to an adhesive system and method for producing a wood based product.

Introduction

Formaldehyde-based resins such as phenol-formaldehyde resin, melamine-formaldehyde resin and urea-formaldehyde resin are widely used as binders in the manufacture of wood-based products. Examples of such wood-based products are composite products containing layers glued together, such as laminated plywood, laminate products and plywood products used, for example, in furniture. Further examples are lumber products, such as particle boards, wood or fiber boards, where wood chips and / or fibers are compressed together with a binder to form boards.

Formaldehyde emissions can occur during the manufacturing process of a wood-based product, and also later, in the process of using the product, after curing the formaldehyde-based resin. The release of formaldehyde into indoor air has remained a big problem for many years, affecting the state of health.

There is an increasing demand for formaldehyde-free wood adhesives that provide sufficient bonding strength and the overall quality of the final product, making them suitable as alternatives to prior art adhesives containing formaldehyde based resins.

Important key properties of wood-based products, reflecting quality, are water resistance and binding strength. In general, in order to meet evaluation standards for private end products, there are specific quality parameters required for this. For example, a particleboard must meet certain standards in terms of, for example, internal adhesion, swelling thickness and water absorption, while laminate products must meet standards in terms of, for example, delamination.

Protein-based adhesives were used in making multi-ply plywood decades ago, but were replaced with formaldehyde-based resins due to their superior effect. Recently, other types of protein based adhesives have been proposed. WO 2005/113700 A1, US 2004/0037906 and US 2004/0089418 disclose adhesive compositions based on soy protein. A further example of a protein-based adhesive is disclosed in Li et al., “Soy-based adhesives with 1,3-dichloro-2-propanol as a curing agent”, Wood and Fiber Science, 36 (2), 2004, pp. 186-194. US 2002/0005251 discloses an adhesive based on a single soy protein. US 2005/0166796 discloses an adhesive composition containing a separate soy protein. US 6790271 and US 2005/0234156 disclose adhesive compositions containing a separate soy protein used to make a particleboard. Mori et al., "A honeymoon-type adhesive for wood products ...", J. of applied polymer science, Vol. 91, 2966-2972 (2004) discloses acetoacetylated polyvinyl alcohol in wood adhesives, but not in combination with any protein.

There is still a need for an adhesive for wood based on an alternative protein that provides high bonding strength and high product quality.

Accordingly, the present invention provides an adhesive composition that gives excellent bonding strength and product quality under conditions, for example, resistance to water. In addition, a method for producing wood based products is provided.

Invention

The present invention provides an adhesive system containing a protein and one or more polymers (P) containing acetoacetoxy groups.

Under the "adhesive system" in the present description means a combination of two or more components, which is formed and acts as a glue for wood. The term "glue" in the present description also includes the term "binder".

The present invention also relates to a method for producing a wood-based product, comprising applying an adhesive composition comprising a protein and one or more polymers (P) containing acetoacetoxy groups to one or more fragments of a wood-based material and combining the fragments with one or more additional pieces of material, preferably wood based material.

Suitable is the mass ratio of protein to one or more polymers (P) from about 1: 2 to about 100: 1, preferably from about 1: 1 to about 100: 1, more preferably from about 1: 1 to about 20: 1, most preferably from about 2: 1 to about 10: 1.

In one embodiment, the adhesive system comprises an adhesive composition.

The adhesive composition accordingly contains from about 1 to about 99 wt.% Protein, preferably from about 3 to about 75 wt.%, Most preferably from about 5 to about 50 wt.%.

The adhesive composition accordingly contains from about 0.1 to about 99 wt.% One or more polymers (P), preferably from about 1 to about 80 wt.%, More preferably from 2 to about 50 wt.%, Even more preferably from about 2 to about 25 wt.%, Most preferably from about 5 to about 15 wt.%.

The solids content in the adhesive composition is suitably from about 10 to about 95 wt.%, Preferably from about 20 to about 75 wt.%, Most preferably from about 30 to about 50 wt.%.

In one embodiment, the adhesive system comprises protein and one or more polymers (P) as separate components that preferably remain separated until they are actually used in the bonding process. The individual components of the adhesive system can also be mixed for a short period of time before actual use in the gluing process, thereby forming the adhesive composition of the present invention. Under the "short period of time" in the present description, respectively, is indicated less than about 1 hour, preferably less than about 30 minutes, most preferably less than about 15 minutes.

In one embodiment of the method of the invention, the adhesive system is applied as separate components to one or more pieces of wood based material, where one component contains protein and the additional component contains one or more polymers (P).

The protein-containing component may comprise a protein solution or dispersion, or may contain the protein as a dry material. The protein solution and dispersion is predominantly aqueous. Accordingly, the component containing one or more polymers (P) is a solution or dispersion, preferably an aqueous solution or dispersion, or a solid material. Accordingly, in the aqueous composition, contains from about 0.1 to about 99 wt.% Polymer (P), as a separate component of the adhesive system, preferably from about 1 to about 80 wt.%, More preferably from about 2 to about 50 wt.% , even more preferably from about 2 to about 25 wt.%, most preferably from about 3 to about 15 wt.%.

In the case where it is intended to apply on one or more fragments of the material based on wood, in the form of separate components of the adhesive system, it is preferable to sequentially apply the components of the adhesive system containing the first applied component and the second applied component.

In one embodiment of the method of the invention, the first supported component comprises a protein, either as a solution or dispersion, or as a dry material. The second supported component contains a solution or dispersion of one or more polymers (P).

In one embodiment of the method of the invention, the first supported component contains a solution or dispersion of one or more polymers (P), and the second supported component contains a protein, either as a solution or as a dispersion, or as a dry material.

In one embodiment of the method of the invention, the first supported component contains one or more polymers (P) as a solid material, and the second supported component contains a protein, either as a solution or as a dispersion, or as a dry material.

In one embodiment of the method of the invention, a mixture of one or more polymers (P) as a solid material and a protein as a dry material is applied.

In one embodiment of the method of the invention, the first deposited component, which is a solution or dispersion, is dried before the second component is applied. In this case, the first supported component is preferably a solution or dispersion of one or more polymers (P).

Examples of suitable proteins are native proteins, that is, unmodified proteins, and modified proteins derived from, for example, milk (casein), soy, potato, corn, wheat, rice, peas, etc. Examples of suitable soy protein products include soy protein concentrate, soy food, soy protein hydrolysis product, and individual soy protein. A preferred protein is single soy protein (SPI). For use in the present invention, the protein is suitably provided in the form of a product, such as a protein food or a single protein. The protein content of a protein food or a single protein is suitably from about 30 to about 100 wt.%, Preferably from about 50 to about 100 wt.%, Most preferably from about 70 to about 100 wt.%.

An aqueous composition containing 12 wt.% Protein has a viscosity (Brookfield, 12 rpm, 4 turns of the rod, at 20 ° C.) from about 500 to about 5,000,000 mPa * s, preferably from about 1,000 to about 2,000,000 MPa * s, more preferably from about 50,000 to about 1,500,000 mPa * s. most preferably from about 100,000 to about 1,000,000 mPa * s.

One or more polymers (P) respectively have a weight average molecular weight of from about 1,000 to about 5,000,000 g / mol, preferably from about 10,000 to about 2,000,000 g / mol.

The content of acetoacetoxy groups in one or more polymer (P) is respectively from about 0.05 to about 50 mol%, preferably from about 1 to about 30 mol%, most preferably from about 5 to about 20 mol%.

One or more polymers (P) preferably contain acetoacetylated polyvinyl alcohol (AAPVA).

The adhesive system, respectively, additionally contains one or more polymers (P1) containing amino or amide groups, preferably in the form of separate components or in a mixed form with a protein component. Amide groups are preferably amide side groups.

The term "amide groups" as used herein includes formamide groups.

One or more polymers (P1) preferably contain primary amino groups or formamide groups. Preferably, one or more polymers (P1) comprise polyvinylamine, polyvinylformamide, poly (vinyl alcohol-vinyl amine copolymer), poly (vinyl alcohol-vinyl formamide copolymer), polyallyl amine, polyethylene imine or polyamidoamine. Most preferably, one or more polymers (P1) comprise polyvinylamine or polyethylene imine.

One or more polymers (P1) respectively have a weight average molecular weight of from about 1,000 to about 5,000,000 g / mol, preferably from about 10,000 to about 2,000,000 g / mol.

The aqueous composition accordingly contains from about 0.1 to about 99 wt.% Polymer (P1) as a separate component of the adhesive system, preferably from about 1 to about 80 wt.%, Even more preferably from about 2 to about 50 wt. %, even more preferably from about 2 to about 25 wt.%, most preferably from about 3 to about 15 wt.%.

An aqueous composition containing one or more polymers (P1) may further comprise inorganic or organic salts. A portion of one or more polymers (P1) may be ionically charged, preferably cationically charged. In the aqueous composition, the amount of negative counter-ion salts is suitably from 0 to about 50 wt.%, Preferably from about 1 to about 30 wt.%, Most preferably from about 2 to about 20 wt.%.

One or more components of the adhesive system containing protein, polymer (P) and optionally polymer (P1), respectively, or the adhesive composition containing protein and polymer, and optionally polymer (P1), may additionally contain additives and fillers, such as kaolin.

In one embodiment of the method, the adhesive composition is dried after application and then activated by adding water or an aqueous composition containing one or more polymers (P) or an aqueous composition containing one or more polymers (P1).

In one embodiment, the adhesive system comprises a protein, one or more polymers (P) and one or more polymers (P1) as separate components that remain separated until they are actually used in the bonding process. The individual components of the adhesive system can also be mixed for a short period of time before actual use in the gluing process, thereby forming the adhesive composition of the present invention. By "short time" in the present description, respectively, is meant less than about 1 hour, preferably less than about 30 minutes, most preferably less than about 15 minutes.

In one embodiment of the method of the invention, an adhesive system is applied to one or more fragments of a wood-based material as separate components, where one component contains protein, the next component contains one or more polymers (P), and the subsequent component contains one or more polymers (P1). The protein-containing component may comprise a protein solution or dispersion, or may contain the protein as a dry material. A component containing one or more polymers (P), respectively, is a solution or dispersion. A component containing one or more polymers (P1), respectively, is a solution or dispersion.

In one embodiment of the method, the first supported component comprises a protein solution or dispersion, and one or more polymers (P). The protein is dried before applying the second component, which contains a solution or dispersion of one or more polymers (P1).

In one embodiment of the method, the first supported component comprises a solution or dispersion of a protein and one or more polymers (P1). The first component is dried before applying the second component, which contains a solution or dispersion of one or more polymers (P).

In one embodiment of the method, the first supported component comprises a solution or dispersion of one or more polymers (P). The first component is dried before applying the second component, which contains a solution or dispersion of the protein and one or more polymers (P1).

In one embodiment of the method, the first supported component comprises a solution or dispersion of one or more polymers (P1). The first component is dried before applying the second component, which contains a solution or dispersion of the protein and one or more polymers (P).

The amount of protein and one or more polymers (P), and optionally one or more polymers (P1) in the adhesive composition, respectively, is at least 75 wt.% Of components having a molecular weight equal to or more than 1000 g / mol, also respectively from about 75 to about 100 wt.%, preferably at least 85 wt.%, also preferably from about 85 to about 100 wt.%, most preferably at least 95 wt.%, also most preferably from about 95 to about 100 wt.%.

The invention further relates to the use of an adhesive system according to the invention for gluing fragments of wood-based materials to produce a wood-based product.

In one embodiment of the present invention, wood based materials are sheets or parquet boards. In this case, the wood-based material is respectively a laminate, a plywood flooring, a plywood furniture material, a laminated plywood, a wall panel, a roof panel or a glued beam.

In one embodiment of the present invention, fragments of the wood based material are wood chips or wood particles, such as wood chips, shavings, flakes, sawdust, or any similarly ground wood based material. In this case, the wood based product is suitably a wood board, a particle board, or a fiber board, or an oriented chip board.

The moisture content of the wood particles for use in the present invention is suitably from about 0 to about 20 wt.%, Preferably from about 1 to about 10 wt.%, More preferably from about 1.5 to about 5 wt.%.

The mass ratio of wood particles to the adhesive system, in terms of dry weight, is suitably from about 100: 1 to about 1: 1, preferably from about 50: 1 to about 2: 1, more preferably from about 30: 1 to about 2, 5: 1, most preferably from about 15: 1 to about 3: 1.

The method according to the invention accordingly includes the steps of contacting one or more fragments of the wood-based material with the adhesive system of the invention, compressing and thereby joining the fragments of the wood-based material with the subsequent wood-based material. Compression accordingly takes place at elevated temperature. The wood based material can be any type and form of wood based material, such as wood chips, fibers, sheets, layers, veneers, fragments, etc. The method accordingly comprises applying an adhesive composition according to the invention to the surface of a wood-based material, followed by compression. The compression temperature depends on which wood-based product you intend to produce, but is suitably from about 50 to about 250 ° C and preferably from about 70 to about 200 ° C. For wood, particle board or fiber board products, the compression temperature is preferably from about 100 to about 225 ° C, most preferably from about 150 to about 200 ° C. For laminated products such as laminated plywood, laminate or parquet flooring, the compression temperature is preferably from about 70 to about 175 ° C, most preferably from about 90 to about 160 ° C.

Compression time and compression temperature are related so that lower compression temperatures generally require a longer compression time. The manufactured product accordingly also determines the compression temperature and compression time. The compression time is respectively equal to at least about 10 seconds, also respectively from about 10 seconds to about 60 minutes, preferably at least about 30 seconds, also preferably from about 30 seconds to about 30 minutes, most preferably at least at least about 1 minute, also preferably from about 1 to about 15 minutes.

In one embodiment of the method, when layered products are made, the method accordingly comprises applying an adhesive composition according to the invention to a surface such that the adhesive compound contains an initially applied amount of from about 0.1 to about 500 g / m ² . The amount applied depends on the product to be produced: for compression of shaped plywood, it is preferably from about 50 to about 200 g / m ² , for laminate, it is preferably from about 100 to about 160 g / m ² . The appropriate upper limit that is applied by the solution also depends on the type of wood based material. The adhesive composition may be applied to one or both of the surfaces to be joined. If applied to both surfaces, the total amount applied to each surface will correspond to the preferred amounts for a whole specific adhesive bond.

In another implementation of the method, when layered products are manufactured, the method accordingly includes applying to the surface of the adhesive system according to the invention, protein and one or more polymers (P), as separate components. Accordingly, both protein and polymer (P) are applied as aqueous compositions. Alternatively, protein and one or more polymers (P) may be applied to individual surfaces intended to be attached. The total amount of the adhesive system applied to one or both surfaces is such that the adhesive compound will contain an initially applied amount of from about 0.1 to about 500 g / m ² . The amount applied depends on the product to be produced: for compression of shaped plywood, it is preferably from about 50 to about 200 g / m ² , for laminate materials it is preferably from about 100 to about 160 g / m ² . The appropriate upper limit that is applied by the solution also depends on the type of wood based material.

In another implementation of the method, when wood, wood-particle or fiber-board and similar products are produced, the method accordingly includes applying to the wood chips the adhesive system according to the invention in the form of individual protein components and one or more polymers (P).

In the manufacture of wood, particle board or fiber board and the like, when applied individually, the protein may be applied in dry form or be present in an aqueous composition. Preferably, the protein is applied in dry form. One or more polymers (P) may be applied as a solid or as an aqueous composition. Preferably, one or more polymers (P) are first added to the chips, followed by protein.

In one embodiment, in the manufacture of wood, particle board, or fiber board and the like, one or more polymers (P) is applied as an aqueous composition, followed by the addition of protein in dry form.

In one embodiment, in the manufacture of wood, particle board, or fiber board and the like, one or more polymers (P) is applied as a solid, simultaneously with the protein in dry form.

The present invention also relates to a wood-based product obtained by a method for producing a wood-based product.

The wood based product is suitably a wood, particle board or fiber board product. Alternatively, the wood-based product is a suitably laminated product, such as laminated plywood, laminate or parquet product.

A wood, particle board or fiberboard product made according to the invention accordingly has a protein content of from about 1 to about 20 wt.%, Preferably from about 3 to about 15 wt.%, Calculated on dry weight.

A wood, particle board, or fiberboard product made according to the invention accordingly has a polymer containing an acetoacetoxy group from about 0.5 to about 10 wt.%, Preferably from about 1 to about 5 wt.%, Based on dry the weight.

The invention is further illustrated by the following non-limiting examples. Parts and percentages respectively relate to parts of mass percent, unless otherwise noted.

Examples

Example 1

Plywood products were made by applying various compositions on 15x15 cm various chipboards, followed by drying for 5 days. The dried adhesive layers were then re-wetted, followed by lining the boards with a 0.6 mm beech layer. The assemblies were compressed for 1 minute at 130 ° C. Checked the gap layers (chisel).

The compositions were tested:

1) 14 g of individual soy protein (SPI) (Supro®500E from Solae), 100 ml of water,

2) 8 g of individual soy protein (SPI) (Supro®500E from Solae), 50 g of a solution of acetoacetylated polyvinyl alcohol (AAPVA) (Gohsefimer® Z-220 from Nippon Gohsei) (5 wt.%),

3) 8 g of individual soy protein (SPI) (Supro®500E from Solae), 50 g of a solution of acetoacetylated polyvinyl alcohol (AAPVA) (Gohsefimer® Z-220 from Nippon Gohsei) (10 wt.%).

Table 1 First applied component The amount of the first applied Rewetting Layer Break (%) warm cold SPI 2.7 g 1 g of water 20-30 ~ 5 SPI 2.7 g 1g AAPVA
(12 wt.%) 50-60 50-60 SPI + AAPVA
(5 wt.%) 3.7 g 1.4 g of water ~ 90 ~ 30 SPI + AAPVA
(10 wt.%) 3.7 g 1.4 g of water one hundred one hundred SPI + AAPVA
(10 wt.%) 3.7 g 1.1 g of polyvinylamine (11 wt.%) one hundred one hundred

Example 2

A chipboard was made by mixing 864 g of wood chips having a moisture content of 2 wt.% With 205 g of an aqueous solution of approximately 11 wt.% Acetoacetylated polyvinyl alcohol (AAPVA) (Gohsefimer® Z-220 from Nippon Gohsei), followed by mixing with approximately 85 g individual soy protein, (SPI) (Prisolate® 601 EM from Food Partner). SPI had a protein content> 90% by weight. and a dry content of 94 wt.% A chip mixture was formed into a 30 × 30 cm slab and compressed at 185 ° C for three minutes, and compressed into a 16 mm thick slab. The compression sequence was 160 kg / cm ² for 30 s, 40 kg / cm ² for 2.5 minutes and no pressure for the last 30 s. The ultimate strength (internal bond, IB), swelling thickness (TSW), and water absorption (ABS) were measured.

In the same way as the previous one, an additional chipboard was made by mixing 994 g of wood chips having a moisture content of 2 wt.% With approximately 85 g of a separate soy protein (Supro® 500E from Solae). SPI had a protein content of> 90 wt.% And a dry content of 94 wt.%. The tensile strength (intercom, IB) was measured.

table 2 Wood chips
(g) Protein Protein (g) AAPVA (11%) (g) Moisture content before compression (%) IB (kPa) TSW
24 h (%) ABS 24 h (%) 864 SPI 85.3 205 14.6 490 30,2 93.7 994 SPI 79.6 _ 7.8 10 _ * _ * * not measured

Example 3

By mixing 50.7 g of wood chips having a moisture content of 2% by weight, respectively, with 1 g of acetoacetylated polyvinyl alcohol (AAPVA) (Gohsefimer® Z-220 from Nippon Gohsei), presented as an aqueous solution of approximately 16.5% by weight, was made on a smaller scale, particle boards followed by mixing in varying amounts with a separate soy protein (SPI) (Supro® 500E from Solae). SPI had a protein content of> 90 wt.% And a dry content of 94 wt.%. A reference sample without SPI and a reference sample without AAPVA were also obtained. Mixtures of wood chips were compressed into slabs 10 mm thick. Compression was performed for 5 minutes at 9 kg / cm ² and 180-185 ° C. The internal bond strength (IB) was measured by gluing fragments of 5 × 5 cm into two metal blocks and breaking them apart.

Table 3 Protein Amount (SPI) (g) The amount of AAPVA (g) IB (kPa) - one 127 0.2 one 222 0.5 one 359 2 one 480 5 one 322 5 - 176

Claims (17)

1. An adhesive system for gluing fragments of wood-based material containing an adhesive composition containing from about 5 to about 50 wt.% Protein and one or more polymers (P) containing acetoacetylated polyvinyl alcohol. 2. The adhesive system according to claim 1, where the mass ratio of protein to one or more polymers (P) is from about 1: 2 to about 100: 1. 3. The adhesive system according to claim 2, where the mass ratio of protein to one or more polymers (P) is from about 1: 1 to about 20: 1. 4. The adhesive system according to any one of claims 1 to 3, where the adhesive composition contains from about 3 to about 15 wt.% One or more polymers (P). 5. The adhesive system according to any one of claims 1 to 3, additionally containing one or more polymers (P1) containing polyvinylamine, polyvinylformamide, poly (copolymer of vinyl alcohol and vinylamine), poly (copolymer of vinyl alcohol and vinylformamide), polyallyl amine, polyethyleneimine or polyamidoamine. 6. The adhesive system according to claim 5, where one or more polymers (P1) contain polyvinylamine. 7. A method of obtaining a product based on wood, comprising applying the adhesive system according to any one of claims 1 to 6 on one or more fragments of the material based on wood, and combining the fragments with one or more subsequent fragments of the material. 8. The method according to claim 7, where the adhesive system is applied to fragments of a material based on wood, in the form of an adhesive composition. 9. The method of claim 8, where the adhesive composition is dried after application, and later activated by adding water or an aqueous composition containing one or more polymers (P), or an aqueous composition containing one or more polymers (P1) containing polyvinylamine, polyvinylformamide poly (copolymer of vinyl alcohol and vinylamine), poly (copolymer of vinyl alcohol and vinylformamide), polyallyl amine, polyethyleneimine or polyamidoamine. 10. The method of claim 8, where the adhesive system further comprises one or more polymers (P1) containing polyvinylamine, polyvinylformamide, poly (copolymer of vinyl alcohol and vinylamine), poly (copolymer of vinyl alcohol and vinylformamide), polyallyl amine, polyethyleneimine or polyamidoamine . 11. The method according to claim 10, where one or more polymers (P1) contains polyvinylamine. 12. The method according to any one of claims 7 to 11, where the fragments are one or more sheets, parquet boards and plywood. 13. The method of claim 12, wherein the wood-based product is a laminate, plywood flooring, furniture plywood, laminated plywood, wall panel, roof panel, or glazed beam. 14. The method according to any one of claims 7 to 11, where the fragments are wood chips or wood particles. 15. The method according to 14, where the product based on wood is a wood, particle board, or fiber board, or oriented particle board. 16. The product based on wood, obtained by the method according to PP.7-15. 17. The use of the adhesive composition according to claims 1-6 for bonding fragments of materials based on wood, to obtain a product based on wood.