Adhesive using sustainable raw materials

Abstract

To provide an adhesive that enables reduction in use of raw materials derived from fossil fuels while exhibiting performance equivalent to an adhesive using raw materials derived from fossil fuels, without requiring changes to manufacturing equipment, manufacturing methods, or usage methods.SOLUTION: There is provided an adhesive manufactured using one or more sustainable raw materials, wherein the sustainable raw materials are at least one selected from the group consisting of formaldehyde, phenol, methanol, urea, and melamine. The adhesive is an adhesive used for manufacturing wood laminated materials. The adhesive is an adhesive used for manufacturing wood boards.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to adhesives, and more particularly to adhesives made using one or more sustainable raw materials instead of fossil fuel-derived raw materials. [Background technology]

[0002] In recent years, the depletion of fossil fuel resources and global warming have become serious problems, and there has been an increasing movement towards a sustainable society. From the perspective of realizing a sustainable society, the use of biomass, for example, is attracting attention. Biomass is organic matter produced by living organisms through photosynthesis using solar energy from carbon dioxide and water. When biomass is used, it becomes carbon dioxide and water again, making it a so-called carbon-neutral resource. Therefore, the use of biomass can be an effective means of realizing a sustainable society.

[0003] Therefore, the practical application of biomass-derived resins made from biomass as a raw material is rapidly progressing, and attempts are being made to produce various resins that have traditionally been produced from fossil fuel-derived raw materials from, for example, plant-derived biomass raw materials. In the adhesives field, research is being conducted on adhesives produced by replacing the fossil fuel-derived resin, which is the main component of the adhesive, with a biomass-derived resin, and methods for producing such adhesives. For example, with regard to phenolic resin-based adhesives, research is being conducted on adhesives whose main component is a lignin-modified phenolic resin, in which part of the phenolic resin produced from fossil fuel-derived raw materials is replaced with lignin, a plant-derived resin, and methods for producing such adhesives. For example, a method for producing a kraft lignin (K)-containing phenolic resin that can achieve optimal viscosity for application, good storage stability, and peel test and temporary adhesion test results when the non-volatile content of the kraft lignin (K) and the phenolic resin are comparable has been proposed (Patent Document 1). This method involves heat-treating an aqueous solution containing 10 to 60 parts by mass of kraft lignin (K) as an active ingredient and 0.05 to 10 parts by mass of an acid (A) having a pH of 1.8 or less at 0.1 mol / L, excluding acids having a carboxyl group, per 100 parts by mass of phenols (P), at a temperature of 85°C or higher, and then producing a phenolic resin (Patent Document 1). Furthermore, for example, a method for producing a lignin-modified resol-type phenolic resin has been proposed with the aim of improving the yield of a known method for producing a lignin-modified phenolic resin (Patent Document 2), which includes the steps of: obtaining a first mixture containing phenols, water, and lignins, wherein the ratio of the phenols to the water is 1:0.03 to 1:1.5 by mass; heating the first mixture at a temperature of 70°C to 120°C and a pH of 7 or less to dissolve the lignins in the phenols and the water to obtain a second mixture; adding aldehydes and a basic catalyst to the second mixture to adjust the pH to 7.5 to 12 to obtain a third mixture; and heating the third mixture at a temperature of 60°C to 105°C to react the lignins, phenols, and aldehydes in the presence of the basic catalyst to obtain a lignin-modified resol-type phenolic resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7220824 [Patent Document 2] Japanese Patent Application Publication No. 2024-15513 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention can reduce the amount of raw materials used that are derived from fossil fuels, and can also reduce the manufacturing equipment The present invention aims to provide an adhesive that has performance equivalent to that of adhesives using raw materials derived from fossil fuels, without changing the manufacturing method or the method of use. [Means for solving the problem]

[0006] In view of the above circumstances, the inventors conducted extensive research and discovered that by using sustainable raw materials for the raw materials themselves used in adhesives, it is possible to reduce the amount of fossil fuel-derived raw materials used, and to provide an adhesive with performance equivalent to that of adhesives using fossil fuel-derived raw materials without changing the manufacturing equipment, manufacturing method, or method of use, thereby completing the present invention.

[0007] That is, the present invention relates to adhesives made using one or more sustainable raw materials.

[0008] The sustainable raw material is preferably at least one selected from the group consisting of formaldehyde, phenol, methanol, urea, and melamine.

[0009] The adhesive is preferably an adhesive used in the production of laminated wood lumber.

[0010] The adhesive is preferably an adhesive used in the manufacture of wood boards. [Effects of the Invention]

[0011] According to the present invention, it is possible to reduce the amount of raw materials derived from fossil fuels used, and to provide an adhesive that has performance equivalent to that of adhesives that use raw materials derived from fossil fuels, without changing the production equipment, production method, or usage method. DETAILED DESCRIPTION OF THE INVENTION

[0012] [glue] The present invention relates to adhesives made using one or more sustainable raw materials.

[0013] <Sustainable raw materials> In this specification, sustainable raw materials refer to raw materials that can be supplied stably over the long term and raw materials from which products are manufactured that do not have a negative impact on the environment, and more specifically, they refer to biomass raw materials and circular raw materials.

[0014] As used herein, biomass refers to renewable, biologically derived organic resources excluding fossil fuels. Examples of such biomass include woody biomass, construction waste biomass, agricultural, livestock, and fishery biomass, food industry biomass, household biomass, and paper mill biomass. In this specification, renewable also includes reusable and recyclable materials.

[0015] Examples of woody biomass include wood (forestry residues, sawmill waste, thinned wood, fuelwood), rosin, sawdust, bark, and wood fiber (cellulose-based materials).

[0016] Examples of construction waste biomass include demolition materials.

[0017] Agricultural, livestock, and aquatic biomass includes, for example, branches, brush, stalks, corn and corn husks, energy crops, forest stands, fruits, flowers, grains, grasses, herbaceous crops, leaves, bark, needles, firewood, roots, seedlings, short rotation timber crops, shrubs, switchgrass, trees, vegetables, fruit peels, vines, sugar beets, sugar beet pulp, wheat midlings, oat husks, hard and soft wood (excluding wood containing hazardous substances), and agricultural residues. (Sugarcane residue (bagasse), rice husks, sorghum, bamboo, wheat straw, rice straw, corn residue, rice bran, plants, beer lees, etc.), glue, casein, wax, livestock waste (bird droppings, pig manure, cow manure, etc.), sugar, starch, sweet potato, rapeseed, palm oil, etc.

[0018] Examples of food industry biomass include food waste, waste cooking oil (UC oil), food processing waste, and fishery processing residues.

[0019] Examples of domestic biomass include sewage sludge, human waste, kitchen waste, garden trees, and industrial cooking oil.

[0020] Examples of biomass from paper mills include black liquor, tall oil, waste wood, and cellulose (waste paper).

[0021] The sustainable raw materials used in the present invention also include biogas generated by fermentation treatment, such as microbial fermentation, in which biomass raw materials are brought into contact with microorganisms under anaerobic conditions. Examples of biomass raw materials used to generate biogas include food waste, agricultural residues, sewage sludge, and livestock waste.

[0022] The sustainable raw materials used in the present invention also include biomass decomposition gas obtained by pyrolysis of biomass raw materials. Examples of biomass raw materials from which biomass decomposition gas can be obtained include highly moist biomass (woody biomass, sludge, manure, food waste, and organic waste such as rice husks and beer dregs). These highly moist biomass can be heated to produce decomposition gases such as carbon monoxide, methane, and hydrogen.

[0023] The sustainable raw materials used in the present invention also include bionaphtha. Bionaphtha is produced from biomass raw materials and is a hydrocarbon equivalent to petroleum-derived naphtha. The bionaphtha is fed into a heated cracking furnace to obtain cracked gas, which can then be fractionated in a cracked gas fractionator to produce ethylene, propylene, butadiene, benzene, toluene, xylene, and other compounds.

[0024] As used herein, circular raw materials refer to materials obtained by physically and / or chemically processing non-biological renewable materials. Non-biological sources may include fossil fuels. Examples of such circular raw materials include waste oil, refuse-derived fuel (RDF), mixed plastic waste, waste tires, waste textiles, and carbon dioxide (derived from industrial emissions).

[0025] The sustainable raw materials used in the present invention also include circular gases generated by subjecting circular raw materials to at least one treatment selected from the group consisting of physical treatment, chemical treatment, and fermentation treatment such as microbial fermentation. Examples of circular raw materials used to generate circular gases include waste oil, refuse-derived fuel, mixed plastic waste, waste tires, and waste textiles.

[0026] The sustainable raw materials used in the present invention also include circular cracked gas obtained by thermal decomposition of circular raw materials. Examples of circular raw materials from which circular cracked gas can be obtained include waste oil, refuse-derived fuel, mixed plastic waste, waste tires, and waste textiles.

[0027] The sustainable raw material of the present invention also includes circular naphtha. The circular naphtha is produced from circular raw materials and is a hydrocarbon equivalent to petroleum-derived naphtha. Examples of circular naphtha include recycled naphtha obtained by recycling renewable waste oil, etc. Examples include oil.

[0028] The adhesive of the present invention is produced from the above-mentioned sustainable raw materials or chemical substances produced from the above-mentioned sustainable raw materials (hereinafter also referred to as chemical substances derived from sustainable raw materials. For example, metamel produced from the above-mentioned sustainable raw materials is also referred to as methanol derived from sustainable raw materials). The above-mentioned chemical substances derived from sustainable raw materials include any chemical substances produced from the above-mentioned sustainable raw materials. Examples of such chemical substances include, but are not limited to, methanol, formaldehyde, urea, melamine, phenol, etc. In this specification, for convenience, the above-mentioned chemical substances derived from sustainable raw materials are also referred to as sustainable raw materials. The adhesive of the present invention can be produced by using one or more sustainable raw materials to produce the main component of the adhesive (in the case of synthetic resin-based adhesives described below, this corresponds to the synthetic resin that constitutes the adhesive). It is not necessary for all of the main components of the adhesive to be produced from sustainable raw materials; they can also be produced by using sustainable raw materials in combination with fossil fuel-derived raw materials. Furthermore, the greater the amount of sustainable raw materials used in the production of the adhesive (hereinafter also referred to as the sustainable raw material usage ratio), the more the amount of fossil fuel-derived raw materials can be reduced, but there is no particular lower limit. The amount of sustainable raw materials used is, for example, 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 98% by mass or more, or 99% by mass or more, based on the total mass (excluding water) of all blended raw materials, including sustainable raw materials and fossil fuel-derived raw materials, used in the production of the adhesive. Furthermore, sustainable raw materials may be used in addition to the main component of the adhesive.

[0029] Methanol derived from sustainable raw materials can be produced by conventionally known methods, including pyrolysis of plant-derived biomass, such as woody biomass or agricultural, livestock, and aquatic biomass, to extract carbon monoxide and hydrogen, which are then converted into methanol using a catalyst. Another method involves extracting carbon monoxide and hydrogen from circular gas and converting them into methanol using a catalyst. The properties of methanol derived from sustainable raw materials produced by these methods are no different from those of methanol derived from fossil fuels.

[0030] Sustainably derived formaldehyde is produced using, for example, sustainable methanol, and can be produced by conventionally known methods such as the excess methanol method or the excess air method. The properties of sustainable formaldehyde produced by these methods are no different from those of fossil fuel-derived formaldehyde.

[0031] Urea derived from sustainable raw materials is produced, for example, using ammonia and carbon dioxide, one or both of which are derived from sustainable raw materials. Ammonia derived from sustainable raw materials can be produced, for example, by treating biomass, such as food industry biomass, which is rich in protein, such as food waste, using microorganisms. On the other hand, carbon dioxide derived from sustainable raw materials can be produced, for example, by extracting carbon dioxide from industrial exhaust gases. The properties of urea derived from sustainable raw materials produced by these methods are no different from urea derived from fossil fuels.

[0032] Melamine derived from sustainable raw materials is produced using, for example, urea derived from sustainable raw materials, and can be produced by low-pressure or high-pressure processes. The properties of melamine derived from sustainable raw materials produced by these processes are no different from melamine derived from fossil fuels.

[0033] Phenol derived from sustainable raw materials is produced by, for example, saccharifying plant-derived biomass contained in wood biomass or agricultural, livestock, and marine biomass, followed by bioconversion using microbial fermentation. Alternatively, it can be produced from bio-naphtha. The properties of phenol derived from sustainable raw materials produced by these methods are no different from phenol derived from fossil fuels.

[0034] The adhesive of the present invention can be produced using one or more sustainable raw materials. For example, the adhesive of the present invention can be produced by replacing the fossil fuel-derived raw materials used in conventionally known adhesives with one or more sustainable raw materials. The adhesive may be, for example, an organic adhesive.

[0035] Examples of organic adhesives include natural resin adhesives, semi-synthetic adhesives, and synthetic resin adhesives. Among these adhesives, the synthetic resin constituting the synthetic resin adhesive is produced using fossil fuel-derived raw materials, but the adhesive of the present invention is obtained by replacing it with one or more sustainable raw materials.

[0036] Examples of synthetic resin adhesives include thermosetting synthetic resin adhesives, thermoplastic synthetic resin adhesives, elastomer synthetic resin adhesives, and composite synthetic resin adhesives.

[0037] Examples of thermosetting synthetic resin adhesives include adhesives whose main component is a urethane resin such as thermosetting polyurethane or moisture-curing polyurethane, polyester, phenolic resin, lignin-phenolic resin, resorcinol resin, phenol-resorcinol resin, epoxy resin, diglycidyl ether epoxy resin, dimer acid epoxy resin, diglycidyl ester epoxy resin, phenolic epoxy resin, urethane-modified epoxy resin, nitrile-modified epoxy resin, alicyclic epoxy resin, silicone resin, urea resin, melamine resin, urea-melamine resin, epoxy asphalt, polyester polyisocyanate, furan resin, polyethyleneimine, isocyanate resin, diallyl phthalate resin, etc. These may be used alone or in combination of two or more.

[0038] Examples of thermoplastic synthetic resin adhesives include adhesives whose main component is polyvinyl alcohol (PVA), polyvinyl hofmar, polyvinyl butyral, polyvinyl ether, polyvinyl chloride (PVC), polyvinyl acetate, vinyl acetate-vinyl chloride copolymer, post-chlorinated vinyl resin, vinyl acetate-ethylene copolymer, acrylic resin, methacrylic resin, cyanoacrylate, vinyl acetate-acrylate copolymer, polystyrene, polyamide resin, thermoplastic polyester, polyether, etc. These may be used alone or in combination of two or more.

[0039] Examples of elastomer synthetic resin adhesives include adhesives whose main component is recycled rubber, chloroprene rubber, silicone rubber, nitrile rubber, styrene butadiene rubber, neoprene rubber, butyl rubber, polyisobutylene rubber, polyurethane rubber, polysulfide rubber, etc. These may be used alone or in combination of two or more.

[0040] Examples of composite synthetic resin adhesives include adhesives whose main component is polyvinyl hofmar phenolic, polyvinyl butyral phenolic, nitrile phenolic, neoprene phenolic, nylon epoxy, etc. These may be used alone or in combination of two or more.

[0041] The adhesive may be a one-component curing type or a two-component curing type, and the adhesive may be in the form of a water-dispersed adhesive, a solution-based adhesive, a reaction-based adhesive, a solid-based adhesive, or a tape-based adhesive.

[0042] Adhesives are also classified according to their hardening method into dry-hardening adhesives such as water-soluble, emulsion, and latex types; chemical reaction adhesives that harden when a crosslinking reaction occurs by mixing the base agent with a hardener; hot melt adhesives that are solid at room temperature but melt when heated and harden when cooled; and pressure-sensitive adhesives that adhere by applying pressure to a highly viscous, fluid liquid. This may also be the case.

[0043] Among the above adhesives, adhesives containing phenol resin, urea resin, melamine resin, urea-melamine resin or lignin-phenol resin as a main component are preferred.

[0044] Furthermore, the adhesive is preferably one that can be used as an adhesive for plywood, an adhesive for wood boards, a binder for heat insulating materials such as glass wool and rock wool, or an adhesive for floors.

[0045] Examples of raw materials for the plywood adhesive include, but are not limited to, formaldehyde, methanol, phenol, urea, furfuryl alcohol, sodium hydroxide, resorcinol, and melamine.

[0046] The plywood adhesive is particularly suitable for use in the production of laminated wood lumber, such as ordinary plywood, structural plywood, floor base material plywood, formwork plywood, other plywood for construction materials, laminated veneer lumber (LVL), laminated veneer board (LVB), cross-laminated lumber (CLT), and extra-thick plywood.

[0047] Examples of raw materials for adhesives for wood boards include, but are not limited to, formaldehyde, methanol, urea, melamine, sodium hydroxide, formic acid, aqueous ammonia, phenol, and polyvinyl alcohol.

[0048] Examples of wood boards include particle board, medium density fiberboard (MDF), and oriented strand board (OSB).

[0049] The adhesive of the present invention may be used alone or in combination of two or more kinds.

[0050] In addition to the above components, the adhesive of the present invention may contain additives commonly used in adhesives, etc., within the scope of not impairing the effects of the present invention. Examples of such additives include, but are not limited to, curing agents, crosslinking agents, waxes, antioxidants, UV absorbers, fillers, pigments, dyes, antistatic agents, flame retardants, antifoaming agents, antibacterial agents, and deodorizers. The above-mentioned sustainable raw materials may also be used for the additives.

[0051] <Adhesive manufacturing method> The adhesive of the present invention can be produced by any known method, and the production method is not particularly limited, such as a method in which the sustainable raw materials and additives other than the sustainable raw materials are charged into a reactor equipped with a stirring blade or a stirring kneader equipped with a heating device, and stirred or kneaded while heating.

[0052] The heating temperature during stirring or kneading is not particularly limited and is, for example, from 60° C. to 120° C., for example, from 80° C. to 100° C. The stirring or kneading time is not particularly limited and is, for example, from 5 minutes to 300 minutes, for example, from 30 minutes to 180 minutes, for example, from 60 minutes to 120 minutes.

[0053] <Adhesive body and its manufacturing method> An adhesive body can be formed by a method including a coating step of applying the adhesive of the present invention to one surface of a first substrate to form an adhesive layer, and a bonding step of bonding the first substrate and a second substrate via the adhesive layer.

[0054] The substrates used as the first substrate and the second substrate are not particularly limited, and examples thereof include paper, woody materials such as wood, porous substrates made of natural materials such as cellulose-based materials and cotton-based materials, nonwoven substrates, and the like. Examples include fabric materials such as cloth; plastic materials such as polyvinyl chloride resin, polyolefin (polypropylene, polyethylene, ethylene-propylene copolymer, etc.), polyurethane, polyester, epoxy, nylon, polycarbonate, acrylic, ABS, polycarbonate (PC) ABS; rubber materials such as natural rubber and synthetic rubber; metal materials such as aluminum, iron, stainless steel; and inorganic materials such as ceramics. The shape of each substrate is not particularly limited and may be, for example, a sheet, foil, plate, molded product, etc. Furthermore, each substrate may be made of only one type of material, or may be made of two or more types of material.

[0055] The adhesive of the present invention is suitable for use as an adhesive in laminated wood lumber. Accordingly, wood materials are preferred as the first substrate and the second substrate, and examples of such wood materials include ordinary plywood, structural plywood, floor base plywood, formwork plywood, other plywood for construction materials, laminated veneer lumber (LVL), laminated veneer board (LVB), cross-laminated lumber (CLT), and extra-thick plywood.

[0056] The laminated wood material is not limited to two layers. Therefore, in addition to the first and second substrates, for example, a third substrate, a fourth substrate, a fifth substrate, etc. may be laminated, which may be the same as or different from the first and second substrates.

[0057] The adhesive of the present invention may be used alone or in combination with two or more types in the wood laminate. For example, two or more types of adhesives may be used to bond the first and second substrates, or one type of adhesive may be used to bond the first and second substrates, and a different adhesive may be used to bond the second and third substrates from the adhesive used to bond the first and second substrates, for a total of two adhesives.

[0058] In the coating step, known methods can be used to coat the substrate, such as spiral spray coating, slot coater coating, curtain spray coating, roll coater coating, omega coating, dot coating, and bead coating.

[0059] The bonding method in the bonding step is not particularly limited. For example, pressure bonding may be performed using a simple method such as fingers, a trowel, or a roller without using any device. Alternatively, known methods such as known press bonding methods and vacuum molding methods may be used.

[0060] <Wood board and its manufacturing method> Furthermore, a wood board can be obtained by mixing the adhesive of the present invention with a lignocellulosic material such as wood chips or wood fibers obtained from biomass raw materials, particularly lumber waste, to obtain an adhesive mixture, and then molding the adhesive mixture. The wood board is produced by mixing the lignocellulosic material with a thermosetting synthetic resin adhesive such as phenolic resin, melamine resin, urea resin, urea-melamine resin, or isocyanate resin, followed by heating and pressure molding. Examples of wood boards include particle board, medium-density fiberboard (MDF), and oriented strand board (OSB).

[0061] The adhesive mixture for producing wood boards is obtained by mixing the adhesive of the present invention, water, a curing agent, additives such as diphenylmethane diisocyanate (MDI) and wax, and lignocellulosic materials such as wood chips. One type of adhesive may be used alone, or two or more types may be used in combination.

[0062] The method for heat-pressure molding the adhesive mixture is not particularly limited, and for example, a known press molding method can be used. The temperature, pressure, and heating and pressing time during the heating and pressing process can be selected as appropriate. The temperature during the heating and pressing is about 170°C to 230°C, the pressure is about 1 MPa to 15 MPa, and the heating and pressing time is about 1 minute to 10 minutes. [Example]

[0063] The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these. In the following description, "parts" means "parts by mass," and the figures in parentheses after the descriptions of bone-dry state and air-dry state, such as (less than 4%), indicate the moisture content.

[0064] [Example 1] 968 parts of biomass-derived formaldehyde [manufactured by MGC Woodchem Co., Ltd.], 162.8 parts of fossil fuel-derived methanol [manufactured by Mitsubishi Gas Chemical Co., Ltd.], 1000 parts of fossil fuel-derived phenol [manufactured by Mitsubishi Chemical Corporation], and 1769.2 parts of water were charged into a reactor, and 250 parts of 25% caustic soda was added as a reaction catalyst. The mixture was heated to 80°C, and then the kinematic viscosity measured using an Ostwald viscometer in the temperature range of 80°C to 95°C was 100mm. 2 The reaction was continued for about 60 minutes until the kinematic viscosity reached 200 mm / s, which was the end point of the primary reaction. After that, 700 parts of 25% caustic soda was added and the reaction was continued for another 100 minutes. When the kinematic viscosity measured using an Ostwald viscometer reached 200 mm / s, 2 / s, cooling was started, and 50 parts of fossil fuel-derived urea (manufactured by Mitsui Chemicals, Inc.) and 100 parts of water were added, followed by cooling to room temperature to obtain the desired plywood adhesive of Example 1.

[0065] [Example 2] An adhesive for plywood of Example 2 was obtained in the same manner as in Example 1, except that biomass-derived methanol (manufactured by Mitsubishi Gas Chemical Company, Inc.) was used instead of fossil fuel-derived methanol.

[0066] [Example 3] The plywood adhesive of Example 3 was obtained in the same manner as in Example 1, except that biomass-derived methanol (manufactured by Mitsubishi Gas Chemical Company, Inc.) and biomass-derived phenol (manufactured by Mitsui Chemicals, Inc.) were used instead of fossil fuel-derived methanol and fossil fuel-derived phenol.

[0067] [Example 4] The plywood adhesive of Example 4 was obtained in the same manner as in Example 1, except that biomass-derived methanol (manufactured by Mitsubishi Gas Chemical Co., Inc.), biomass-derived phenol (manufactured by Mitsui Chemicals, Inc.), and biomass-derived urea (manufactured by Mitsui Chemicals, Inc.) were used instead of fossil fuel-derived methanol, fossil fuel-derived phenol, and fossil fuel-derived urea.

[0068] [Comparative Example 1] A plywood adhesive of Comparative Example 1 was obtained in the same manner as in Example 1, except that fossil fuel-derived formaldehyde (manufactured by MGC Woodchem Co., Ltd.) was used instead of biomass-derived formaldehyde (all raw materials derived from fossil fuels were used).

[0069] [Example 5] 200 parts of biomass-derived urea [manufactured by Mitsui Chemicals, Inc.], 220 parts of fossil fuel-derived formaldehyde [manufactured by MGC Woodchem Co., Ltd.], 37 parts of fossil fuel-derived methanol [manufactured by Mitsubishi Gas Chemical Co., Ltd.], 263 parts of water, 0.5 parts of 25% caustic soda, 40 parts of fossil fuel-derived melamine [manufactured by Mitsui Chemicals, Inc.], and 1 part of 25% aqueous ammonia were charged into a reactor, heated to 80°C, and the reaction was allowed to proceed for about 10 minutes. After that, 2 parts of 20% formic acid were added, and the kinematic viscosity measured using an Ostwald viscometer was 60 mm 2After the reaction was continued for about 75 minutes until the kinematic viscosity reached 100 mm / s, 0.5 parts of 25% caustic soda and 20 parts of biomass-derived urea were added and the reaction was continued for another 40 minutes. 2 At this point, 1.0 part of 25% caustic soda and 220 parts of biomass-derived urea were added to begin cooling. After cooling, the desired board adhesive of Example 5 was obtained.

[0070] [Example 6] An adhesive for boards of Example 6 was obtained in the same manner as in Example 5, except that biomass-derived formaldehyde (manufactured by MGC Woodchem Co., Ltd.) was used instead of fossil fuel-derived formaldehyde.

[0071] [Example 7] The board adhesive of Example 7 was obtained in the same manner as in Example 5, except that biomass-derived formaldehyde (manufactured by MGC Woodchem Co., Ltd.) and biomass-derived melamine (manufactured by Mitsui Chemicals, Inc.) were used instead of fossil fuel-derived formaldehyde and fossil fuel-derived melamine.

[0072] [Example 8] The board adhesive of Example 8 was obtained in the same manner as in Example 5, except that biomass-derived formaldehyde (manufactured by MGC Woodchem Co., Ltd.), biomass-derived melamine (manufactured by Mitsui Chemicals, Inc.), and biomass-derived methanol (manufactured by Mitsubishi Gas Chemical Company, Inc.) were used instead of fossil fuel-derived formaldehyde, fossil fuel-derived melamine, and fossil fuel-derived methanol.

[0073] Comparative Example 2 A board adhesive of Comparative Example 2 was obtained in the same manner as in Example 5, except that fossil fuel-derived urea (manufactured by Mitsui Chemicals, Inc.) was used instead of biomass-derived urea (all fossil fuel-derived raw materials were used).

[0074] <Adhesion performance evaluation test> 100 parts of the plywood adhesive of Examples 1 to 4 and Comparative Example 1 were mixed with 10 parts of water, 10 parts of wheat flour, 15 parts of calcium carbonate, and 3 parts of soda ash to produce the pastes of Examples 1 to 4 and Comparative Example 1. For the base board and middle board, rotary veneers measuring 3 x 6 shaku (90 x 180 cm) and 2.6 mm thick made from domestic larch were selected. For the glue core veneer, rotary veneers measuring 3 x 6 shaku and 2.6 mm thick made from cedar were selected. All veneers were used in an absolute dry state (less than 4%). The glue core veneer was coated on both sides with the glue liquid from Examples 1 to 4 and Comparative Example 1 at 38 g / shaku 2 (g / 30.3 cm square), and assembled into a total of five layers (5 plies) consisting of base board (2.6 mm) / glue core veneer (2.6 mm) / middle board veneer (2.6 mm) / glue core veneer (2.6 mm) / base board (2.6 mm), and pressure was applied at 10 kgf / cm so that the thickness of the plywood after bonding would be 12 mm. 2 After 20 minutes of cold pressing at 130℃ 10kgf / cm 2 The plywood was molded by hot pressing for 360 seconds (30 seconds / mm). Next, the obtained plywood was cut into test pieces 2.5 cm wide x 7.5 cm long, and the adhesive strength and wood breakage rate were measured using the repeated steaming test (special type test) specified in the Japanese Agricultural and Forestry Standards for plywood (JAS 0233-2). In the steaming cycle test, the test piece was immersed in room temperature water for at least 2 hours, then steamed at 130±3°C for 2 hours, immersed in running water at room temperature for 1 hour, steamed again at 130±3°C for 2 hours, and immersed in room temperature water until cooled. An adhesive strength test was performed in which the test piece was tensile broken in both ends while still wet, and the adhesive strength (maximum load) and wood breakage rate were measured, and the average adhesive strength and average wood breakage rate were calculated. The wood breakage rate means the percentage of broken wood remaining attached to the adhesive layer for the test piece used for adhesive strength measurement. Average adhesive strength (kgf / cm) for n=4 tests 2 ) is 1.0kgf / cm 2 Above: 〇, 1.0kgf / cm 2 Those with a value of less than this were evaluated as x. Tests with n = 4 showed that the average wood fracture rate (%) was 50% or more, and tests with less than 50% were rated as ◯. The results of the evaluation are shown in Table 1 below. The sustainable raw material usage ratio (% indicates mass %) shown in Table 1 was calculated excluding water.

[0075] [Table 1]

[0076] The results shown in Table 1 indicate that the plywood adhesives of Examples 1 to 4, which were produced using biomass raw materials included in sustainable raw materials, were evaluated as equivalent in average adhesive strength and average wood fracture rate to the plywood adhesive of Comparative Example 1, which was produced using raw materials derived from fossil fuels. Furthermore, it was shown that the evaluations of average adhesive strength and average wood fracture rate did not change even when the proportion of sustainable raw materials used was gradually increased from the plywood adhesive of Example 1 to the plywood adhesive of Example 4.

[0077] An adhesive mixture was obtained by mixing 100 parts of the board adhesive of Examples 5 to 8 and Comparative Example 2, 100 parts of water, 100 parts of diphenylmethane diisocyanate (MDI) [manufactured by Sumika Covestro Urethane Co., Ltd.], and 1,000 parts of wood chips with a moisture content of 2%. The adhesive mixture was poured into a mold measuring 32.5 cm in length and 32.5 cm in width to produce a mat (adhesive mixture formed into a plate shape). Next, after removing the mold, 16 mm square spacer rods were placed on both sides of the mat, and the mat was subjected to hot-press molding at a temperature of 185°C for a pressing time of 250 seconds to produce a wood board. The manufactured wood boards were cut into test pieces according to the dimensions specified in JIS A 5908, and the test pieces were evaluated for bending strength, wet bending strength (Test A), peel strength, and water absorption thickness swelling rate in accordance with JIS A 5908.

[0078] The bending strength test was carried out using a Tensilon universal material testing machine (manufactured by Orientec Co., Ltd., model number RTC-1350A), and a load was applied to the test piece at a span of 22.5 cm and an average deformation speed of approximately 10 mm / min to measure the maximum load. The bending strength was then calculated using the following formula (1). σ=3PL / 2bt 2 Formula (1) (σ: bending strength (N / mm 2 ), P: Maximum load (N), L: Span (mm), b: Width of specimen (mm), t: Thickness of specimen (mm) Bending strength (N / mm 2 ) is 12.0N / mm 2 Above: 〇, 12.0N / mm 2 Those with a value of less than 100% were evaluated as X. The evaluation results are shown in Table 2 below.

[0079] For the wet flexural strength (Test A), the test piece was immersed in warm water at 70±3°C for 2 hours, then immersed in water at room temperature for 1 hour, and then subjected to the same test as the flexural strength test while still wet, to measure the maximum load, and the flexural strength was calculated using the formula (1). Wet bending strength (N / mm 2 ) is 4.0N / mm 2 Above: 〇, 4.0N / mm 2 Those with a value of less than 100% were evaluated as X. The evaluation results are shown in Table 2 below.

[0080] In the peel strength test, the test piece was attached to an aluminum block, which was a jig for setting it in a Tensilon universal material testing machine (Orientec Co., Ltd., model RTC-1350A), and a tensile load was applied perpendicular to the surface of the test piece to measure the maximum load at the time of peel failure.The peel strength was then calculated using the following formula (2). IB=P' / b×L Equation (2) (IB: Peel strength (N / mm 2 ), P': maximum load at peel failure (N), b: width of test piece (mm), L: length of test piece (mm) Peel strength (N / mm 2 ) is 0.6N / mm 2 Above: 〇, 0.6N / mm 2 Those with a value of less than 100% were evaluated as X. The evaluation results are shown in Table 2 below.

[0081] In the water absorption thickness swelling test, the thickness of the central part of the test piece was measured in advance using a micrometer with an accuracy of 0.005 mm, and the test piece was immersed in water at 20°C ± 1°C for 24 hours. After that, the test piece was taken out, the water was wiped off, and the thickness of the central part was measured. The water absorption thickness swelling rate was calculated using the following formula (3). TS=(t2-t1 / t1)×100 Equation (3) (TS: Water absorption thickness expansion rate (%), t1: Thickness before water absorption (mm), t2: Thickness after water absorption (mm)) Those with a water absorption thickness swelling rate (%) of less than 15% were evaluated as ◯, and those with a water absorption thickness swelling rate of 15% or more were evaluated as ×. The evaluation results are shown in Table 2 below. Note that the sustainable raw material usage rate (% indicates mass %) shown in Table 2 was calculated excluding water.

[0082] [Table 2]

[0083] The results shown in Table 2 indicate that the wood boards manufactured using the board adhesives of Examples 5 to 8, which were manufactured using biomass raw materials included in sustainable raw materials, were evaluated as equivalent in bending strength, wet bending strength (Test A), peel strength, and water absorption thickness swelling rate to the wood board manufactured using the board adhesive of Comparative Example 2, which was manufactured using raw materials derived from fossil fuels. Furthermore, it was shown that even when the proportion of sustainable raw materials used was gradually increased from the board adhesive of Example 5 to the board adhesive of Example 8, the evaluations of bending strength, wet bending strength (Test A), peel strength, and water absorption thickness swelling rate did not change. [Industrial Applicability]

[0084] The adhesives made from sustainable raw materials of the present invention can reduce the amount of fossil fuel-derived raw materials used, and have the same performance as adhesives made from fossil fuel-derived raw materials without requiring changes to the manufacturing equipment, manufacturing method, or usage method, so they can be used in place of any adhesives made solely from fossil fuel-derived raw materials.

Claims

1. Adhesives made from one or more sustainable raw materials.

2. The adhesive according to claim 1 , wherein the sustainable raw material is at least one selected from the group consisting of formaldehyde, phenol, methanol, urea, and melamine.

3. 3. The adhesive of claim 2, which is an adhesive used in the production of laminated wood lumber.

4. The adhesive of claim 2, which is an adhesive used in the manufacture of wood boards.

Images