Application of a wood reorganizing agent in the preparation of adhesives for the wood industry

Abstract

The invention belongs to the field of polymer materials and provides an application of a wood reorganization agent in preparing an adhesive for the wood industry, wherein the weight percentage of the wood reorganization agent in the modified adhesive is 0.01%-10%. The wood reorganization agent is used to modify the adhesive for the wood industry so that the adhesive has excellent water resistance and can also improve its anti-oxidation and anti-aging effects. When the adhesive is used in the preparation of reorganized wood, the strength and dimensional stability of the reorganized wood are improved.

Description

Technical Field

[0001] The invention relates to the field of polymer materials, and specifically provides an application of a wood reorganization agent in the preparation of an adhesive for the wood industry. Background Art

[0002] High-performance recombinant wood is a new type of high-performance natural polymer composite material made from artificial forest wood as raw material and cells as basic units, which is made by directional recombination and resin compounding. It can overcome the defects of artificial forest wood such as small diameter, soft material, low strength and uneven material. It has the characteristics of controllable performance, designable structure and adjustable specifications. It is one of the effective ways to make good use of small materials and inferior materials. It is one of the frontiers and hot spots of current research in the field of natural polymer materials.

[0003] The existing wood industry adhesives used to prepare reconstructed wood have average anti-aging properties and a short lifespan, which will cause the reconstructed wood to fade and powder due to long-term exposure to wind and sun when used in an external environment, limiting its scope of application. In addition, the huge challenges faced by reconstructed wood also come from the bonding strength and the deterioration of dimensional stability or even expansion and cracking when exposed to water after reconstructing.

[0004] In response to this challenge, many solutions have been reported in the literature. For example, CN101357470 improves the bonding strength by debonding the veneer, improving the crack uniformity of the wood bundle and improving the uniformity of the dipping. Although it has a certain effect in comparison, the internal bonding strength is still low, all below 2MPa, and a good effect has not been achieved; CN111171770 uses synergistic silicon-modified phenolic resin to effectively improve the internal bonding strength and saturated water absorption rate of reconstituted wood (internal bonding strength 3.0-5.0Mpa, saturated water absorption rate 12.5-14.9%), but this technology uses the modification method of adding organic salts, which has the defects of poor compatibility or incompatibility with the phenolic glue system, seriously destroying the stability of the phenolic glue system, causing great passivity in large-scale production and use, and difficult to be widely promoted and applied.

[0005] Therefore, whether it is possible to provide an adhesive for the wood industry suitable for reconstituted wood to overcome the many problems existing in the prior art has become one of the problems that technical personnel in the field need to solve urgently. Summary of the invention

[0006] In view of the blank in the above technology, the present invention provides an application of a wood reorganization agent in the preparation of an adhesive for the wood industry, wherein the weight percentage of the wood reorganization agent in the modified adhesive is 0.01%-10%; the wood reorganization agent is used to modify the adhesive for the wood industry so that it has excellent water resistance, and at the same time, the anti-oxidation and anti-aging effects can be improved. When the adhesive is used in the preparation of reorganized wood, the strength and dimensional stability of the reorganized wood are improved.

[0007] Compared with the prior art, the main improvements of the present invention are as follows:

[0008] The inventors organically combined a resin material modifier using 3-chloro-2-hydroxy-propyl as the end-capping group with conventional wood adhesives, improving the problem of uneven wood bundle impregnation, effectively improving the anti-aging performance and dimensional stability of reconstituted wood, and greatly reducing its absorption thickness and absorption width expansion rate indicators. The entire invention has the advantages of simple process, good dimensional stability, excellent anti-aging performance, etc.

[0009] The prior art JP1998130250 and JP3403590B2 have disclosed the preparation method of the above-mentioned 3-chloro-2-hydroxy-propyl as the resin material modifier part of the compound structure of the end group, and the inventor will not repeat it here. In the above-mentioned technology, the compound of the related structure is mainly used in the optical field, and it has the advantages of high refractive index, low dispersion and impact resistance. This application is the first time to use it as a wood reorganization agent for the modification of adhesives for the wood industry, filling the gap in the application of related compounds in this field.

[0010] Based on the above improvement ideas, the main technical solutions of this application are as follows:

[0011] A use of a wood reorganization agent in the preparation of an adhesive for the wood industry, characterized in that the modified adhesive for the wood industry contains 0.01%-10% of the wood reorganization agent by weight, and the wood reorganization agent has the following structure:

[0012]

[0013] Where n=1-4, R is one or more of the following structures:

[0014]

[0015]

[0016] Where R 1 , R 2 , R 3 With R 4 is a C1-C5 alkane group, R 5 It is a C1-C1000 alkane group.

[0017] More preferably, it is one of pentaerythritol tetrakis(3-(3-chloro-2-hydroxy-propylthio)propionate, 3,3'-((thiobis(ethane-2,1-diyl))bis(1-chloropropane-2-ol), 3,3'-thiobis(1-(2-(3-chloro-2-hydroxy-propyl)thioethyl)-2,2'-bis(3-chloro-2-hydroxy-propyl)thiopropyl sulfide, 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, and epichlorohydrin disubstituted PEG-200;

[0018] The most preferred wood restructurer is 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0019] The above-mentioned recombinant is a hydroxyl-terminated compound, which can react with the hydroxyl group in the wood industry adhesive. The recombinant wood after the curing reaction has good water resistance due to the introduction of the poorly water-soluble group in the recombinant, so it can have a good modification effect on the performance of the adhesive.

[0020] At the same time, the water solubility of the above-mentioned recombinant is worse than that of the adhesive for the wood industry. Therefore, it needs the help of the co-solvent alcohol to form a uniform, transparent and stable solution with the adhesive for the wood industry. Therefore, the recombinant is introduced into the adhesive for the wood industry to modify the adhesive, and finally the modified adhesive for the wood industry is obtained. The recombinant wood prepared with it as raw material has significantly improved performance.

[0021] After selecting the above recombinant agent, the inventors further provided a preparation method of the corresponding recombinant agent, the specific steps are as follows:

[0022] Weigh a certain amount of polythiol monomer or polyether polyol monomer or polyester polyol monomer and 1.5 times the mass of methanol of the reactant, stir evenly, add a certain molar amount of epichlorohydrin, continue to stir evenly, and then drop a basic catalyst while stirring, control the reaction temperature of the system to be -15-65°C, the reaction time to be 2-24h, and the reaction end point to be determined by high performance liquid chromatography content, when the content of polythiol monomer or polyether polyol or polyester polyol monomer is less than 3%, it is the end point, and remove the solvent by a rotary evaporator to obtain a wood reorganization agent;

[0023] The molar ratio of the polythiol monomer or the polyether polyol monomer or the polyester polyol monomer to epichlorohydrin is controlled at 1:1-4; the alkaline catalyst used is selected from sodium hydroxide, potassium hydroxide and ammonia water, and the stirring speed is 200r / min-500r / min.

[0024] In addition, other preparation methods in the prior art can also be used to prepare it, and the inventor will not elaborate on them.

[0025] Based on the above-mentioned wood reorganization agent, the inventor further provides the application of the wood reorganization agent in the preparation of an adhesive for the wood industry, specifically: a modified adhesive for the wood industry, which is composed of an adhesive for the wood industry, alcohol, water and a wood reorganization agent, wherein the weight ratio is 20-60 parts of the adhesive for the wood industry, 0.1-50 parts of alcohol, 10-60 parts of water and 0.01%-10% of the wood reorganization agent accounting for the weight of the entire modified adhesive for the wood industry.

[0026] The adhesive for the wood industry is selected from one or more of phenolic resin, epoxy resin, urea-formaldehyde resin, melamine-formaldehyde resin, silicone resin, furan resin, unsaturated polyester, acrylic resin, polyimide, polybenzimidazole, phenolic-polyvinyl acetal, phenolic-polyamide, phenolic-epoxy resin, epoxy-polyamide, cellulose ester, polyvinyl acetate, polyvinyl alcohol, polyester, polyether, polyamide, polyacrylate, α-cyanoacrylate, polyvinyl acetal, ethylene-vinyl acetate copolymer, starch, protein, polyurethane, phenolic-nitrile glue, phenolic-chloroprene glue, phenolic-polyurethane glue, epoxy-nitrile glue, and epoxy-polysulfide glue.

[0027] The alcohol is selected from one or more of methanol, ethanol, propylene glycol, n-butanol, isobutanol and ethylene glycol.

[0028] Preferably, the adhesive for wood industry is selected from one of phenolic resin, epoxy resin, urea-formaldehyde resin, melamine-formaldehyde resin, phenolic-polyvinyl acetal, phenolic-polyamide, phenolic-epoxy resin, polyvinyl alcohol, polyurethane, phenolic-nitrile glue, phenolic-chloroprene glue, and phenolic-polyurethane glue.

[0029] In the above formula, water is used as the main solvent; however, the wood industry adhesive and the wood reconstructor are not miscible, and a co-solvent needs to be added. Therefore, alcohol is used as a co-solvent so that the modifier can form a stable and usable solution with other components in the system. Otherwise, it is difficult to prepare a usable modified wood industry adhesive, and it is too wasteful to use only alcohol as a solvent.

[0030] The preferred modified adhesive for wood industry comprises, by weight, 25-55 parts of adhesive for wood industry, 4-45 parts of alcohol, 15-55 parts of water, and 0.1%-8% of a wood reconstructing agent accounting for the weight of the entire modified adhesive for wood industry;

[0031] The preferred amount of wood restructurer is 2-4%, most preferably 4%.

[0032] The preparation method of the above-mentioned adhesive for wood industry with excellent water resistance comprises the following specific steps:

[0033] (a) adding a wood reorganization agent and alcohol into a reaction kettle and mixing them at room temperature for 30 minutes;

[0034] (b) adding a wood industry adhesive to the mixture in step (a), and mixing with mechanical stirring for 30 minutes;

[0035] (c) adding pure water to the mixture obtained in step (b) to make the content of the wood industry adhesive in the final mixture reach 16wt%-30wt%, that is, obtaining a modified wood industry adhesive with excellent water resistance in a uniform solution state.

[0036] The inventors further provide a method for preparing reconstituted wood using the modified wood industrial adhesive, the specific steps of which are as follows:

[0037] The reconstituted wood substrate is obtained by peeling the veneer, and then performing the processes of dipping, pressing, and high-temperature curing on the veneer. Preferably, the pressing adopts a cold pressing process, and the high-temperature curing adopts a program heating process of 100° C.-1 hour, 120° C.-2 hours, and 140° C.-4 hours, so that the core layer temperature is maintained at 120° C. for 2 hours, cooling, and opening a mold to obtain the reconstituted wood substrate;

[0038] The specific process can be as follows: (1) placing the veneer in a reactor, if it is impregnated at normal pressure, do not apply negative pressure for half an hour; if it is impregnated at pressurized pressure, maintain negative pressure for half an hour; (2) adding the modified phenolic adhesive for wood industry into the reactor, impregnating for 24 hours without applying pressure during normal pressure impregnation, and impregnating at positive pressure of 0.6 MPa for 1 hour during pressurized impregnation; (3) taking out the wood from the reactor, extruding-leaching-extruding for a total of 4-5 minutes, and then drying for 24 hours; (4) curing the impregnated veneer by cold pressing process to prepare reconstituted wood, and curing by programmed temperature rise, 100℃-1h, 120℃-2h, 140℃-4h, and testing the core layer temperature to reach 120℃ and maintain for 2 hours.

[0039] The above method is only an example and can also be applied to other methods for preparing recombinant wood.

[0040] The modified wood industrial adhesive described in the present application was used to prepare reconstituted wood, and the performance test results thereof were as follows: excellent anti-aging effect and substrate dimensional stability were achieved, wherein the thickness expansion rate was ≤3.5%, and the width expansion rate was ≤3%.

[0041] In summary, the present application provides a complete set of technical solutions from the recombinant to the final recombinant wood. Through comprehensive technical improvements, the final recombinant wood has good mechanical properties while also having excellent UV resistance, bonding strength and excellent substrate dimensional stability, thereby maintaining the application performance of the recombinant wood. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Comparison of the results of the small wooden blocks prepared in different embodiments after 7 days in the UV aging test chamber;

[0043] Figure 2 The color comparison of the plywood prepared in Example 4 and Comparative Example 1 after being placed in the laboratory at room temperature for 40 days;

[0044] Figure 3 Color comparison of the solutions prepared in different embodiments after being placed at room temperature in the laboratory for 3 days;

[0045] Depend on Figure 1 , Figure 2 , Figure 3 It can be proved that the reconstituted wood prepared by phenolic adhesive for the modified wood industry and its own glue have anti-aging effect;

[0046] Figure 4 The fluorescence analysis comparison between Example 4, Example 1, Example 2 and Comparative Example 1 is shown;

[0047] Depend on Figure 4 Fluorescence analysis of the veneers impregnated with modified phenolic adhesive for wood industry showed that the glue distribution in the veneers was more uniform, which corresponds to the better effect of the modified glue.

[0048] Figure 5 Liquid phase spectrum of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane prepared in Example 4;

[0049] Figure 6 The Raman spectrum of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol, a raw material used in Example 4;

[0050] Figure 7 This is the Raman spectrum of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane prepared in Example 4. DETAILED DESCRIPTION

[0051] The following is a further detailed description of the above contents of the present invention through specific implementation methods in the form of embodiments, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples. All technologies implemented based on the above contents of the present invention belong to the scope of the present invention, and unless otherwise specified, the following embodiments are all completed using conventional existing technologies.

[0052] Example 1

[0053] The wood reconstitution agent of this embodiment is pentaerythritol tetrakis (3- (3-chloro-2-hydroxy-propylthio) propionate), and its preparation method is as follows:

[0054] Weigh 244.5g of pentaerythritol tetrakis (3-mercaptopropionic acid) ester and 700g of methanol solvent, stir evenly, add 222.1g of epichlorohydrin, continue to stir evenly, add 9.3g of 2% sodium hydroxide aqueous solution while stirring, control the system to react at 0°C, the reaction time is 20 hours, and the stirring speed is 450r / min. The reaction end point is determined by high performance liquid chromatography content, and the end point is when the content of pentaerythritol tetrakis (3-mercaptopropionic acid) ester is less than 3%, and the solvent is removed by rotary evaporator to obtain pentaerythritol tetrakis (3-(3-chloro-2-hydroxy-propylthio) propionic acid) ester.

[0055] An adhesive for the wood industry with excellent water resistance, comprising the following raw materials in parts by weight: 47.61 parts of phenolic adhesive for the wood industry, 0.5 parts of pentaerythritol tetrakis (3-(3-chloro-2-hydroxy-propylthio) propionate), 12 parts of ethanol, and 39.89 parts of water;

[0056] The preparation steps of the above-mentioned modified wood industry phenolic adhesive are as follows:

[0057] (a) adding 0.5 parts of pentaerythritol tetrakis (3-(3-chloro-2-hydroxy-propylthio) propionate) and 12 parts of ethanol into a reaction kettle and mixing them at room temperature for 30 minutes;

[0058] (b) adding 47.61 parts of phenolic adhesive for wood industry into the reactor of step (a) and mixing for 30 minutes;

[0059] (c) adding 39.89 parts of water to the reaction kettle of step (b) to dilute the mixed solution, thereby obtaining a modified phenolic adhesive for wood industry of pentaerythritol tetrakis(3-(3-chloro-2-hydroxy-propylthio)propionate).

[0060] The steps of preparing reconstituted wood using the above-mentioned modified wood industrial phenolic adhesive are as follows:

[0061] (a) Add 1.2 kg of veneer into a 10 L reactor and keep it under vacuum at -0.4 MPa for 0.5 h;

[0062] (b) adding 10 kg of the modified wood industry phenolic adhesive into a reactor and performing positive pressure impregnation at 0.6 MPa for 1 h;

[0063] (c) taking the wood out of the reactor, subjecting it to extrusion-leach-extrusion for a total of 4-5 minutes, and then air-drying it for 24 hours;

[0064] (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood. The temperature is programmed to cure at 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. After the core layer temperature reaches 120°C, it is maintained for 2 hours and then naturally cooled to room temperature.

[0065] Example 2

[0066] The wood reconstitution agent of this embodiment is 3,3'-((thiobis(ethane-2,1-diyl))bis(1-chloropropane-2-ol), and its preparation method is as follows:

[0067] Weigh 77g of 2,2'-thiobis(ethane-1-thiol) and 282g of methanol solvent, stir evenly, then add 111g of epichlorohydrin, continue stirring evenly, then add 3.8g of 2% sodium hydroxide aqueous solution while stirring, control the system to react at 0°C, the reaction time is 20 hours, and the stirring speed is 450r / min. The reaction end point is determined by high performance liquid chromatography content, and the end point is when the content of 2,2'-thiobis(ethane-1-thiol) is less than 3%, and the solvent is removed by rotary evaporator to obtain 3,3'-((thiobis(ethane-2,1-diyl))bis(1-chloropropane-2-ol).

[0068] The invention discloses an adhesive for wood industry with excellent water resistance, comprising the following raw materials in parts by weight: 46.52 parts of phenolic adhesive for wood industry, 1 part of 3,3'-((thiobis(ethane-2,1-diyl))bis(1-chloropropane-2-ol), 21.35 parts of ethanol and 31.13 parts of water.

[0069] The preparation steps of the above-mentioned modified wood industry phenolic adhesive are as follows:

[0070] (a) adding 1 part of 3,3'-((thiobis(ethane-2,1-diyl))bis(1-chloropropane-2-ol) and 21.35 parts of ethanol into a reaction kettle and mixing them at room temperature for 30 minutes;

[0071] (b) adding 46.52 parts of phenolic adhesive for wood industry into the reactor of step (a) and mixing for 30 minutes;

[0072] (c) Add 31.13 parts of water to the reaction kettle of step (b) to dilute the mixed solution, thereby obtaining a phenolic adhesive for wood industry modified with 3,3'-((thiobis(ethane-2,1-diyl))bis(1-chloropropane-2-ol).

[0073] The steps of preparing reconstituted wood by pentaerythritol tetra(3-(3-chloro-2-hydroxy-propylthio) propionate) modified phenolic adhesive for wood industry are as follows:

[0074] (a) Add 1.2 kg of veneer into a 10 L reactor and keep it under vacuum at -0.4 MPa for 0.5 h;

[0075] (b) adding 10 kg of 3,3'-((thiobis(ethane-2,1-diyl))bis(1-chloropropane-2-ol) modified phenolic adhesive for wood industry into a reaction kettle, and performing positive pressure impregnation at 0.6 MPa for 1 h;

[0076] (c) taking the wood out of the reactor, subjecting it to extrusion-leach-extrusion for a total of 4-5 minutes, and then air-drying it for 24 hours;

[0077] (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood. The temperature is programmed to cure at 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. The core layer temperature is tested to be maintained at 120°C for 2 hours and then naturally cooled to room temperature.

[0078] Example 3

[0079] The wood reconstitution agent of this embodiment is 3,3'-thiobis(1-(2-(3-chloro-2-hydroxy-propyl)thioethyl)-2,2'-bis(3-chloro-2-hydroxy-propyl)thiopropyl sulfide, and its preparation method is as follows:

[0080] Weigh 183.4 g of 3,3'-thiobis(1-(2-mercaptoethyl)thiopropane-2,2'-dithiol) and 408 g of methanol solvent, stir evenly, add 222.1 g of epichlorohydrin, continue stirring evenly, add 8.1 g of 2% sodium hydroxide aqueous solution while stirring, control the system to react at 0°C, the reaction time is 20 hours, and the stirring speed is 450 r / min. The reaction end point is determined by high performance liquid chromatography content, and the end point is when the content of 3,3'-thiobis(1-(2-mercaptoethyl)thiopropane-2-thiol) is less than 3%. Use a rotary evaporator to remove the solvent to obtain 3,3'-thiobis(1-(2-(3-chloro-2-hydroxy-propyl)thioethyl)-2,2'-di(3-chloro-2-hydroxy-propyl)thiopropyl sulfide.

[0081] A wood industry adhesive with excellent water resistance comprises the following raw materials in parts by weight: 44.34 parts of wood industry adhesive, 2 parts of 3,3'-thiobis(1-(2-(3-chloro-2-hydroxy-propyl)thioethyl)-2,2'-bis(3-chloro-2-hydroxy-propyl)thiopropyl sulfide, 22 parts of ethanol and 31.66 parts of water.

[0082] The preparation steps of the above-mentioned modified wood industry phenolic adhesive are as follows:

[0083] (a) adding 2 parts of 3,3'-thiobis(1-(2-(3-chloro-2-hydroxy-propyl)thioethyl)-2,2'-bis(3-chloro-2-hydroxy-propyl)thiopropyl sulfide and 22 parts of ethanol into a reaction kettle and mixing them at room temperature for 30 minutes;

[0084] (b) adding 44.34 parts of phenolic adhesive for wood industry to step (a) and mixing for 30 minutes;

[0085] (c) adding 31.66 parts of water to the mixture of step (b) to dilute the mixture, thereby obtaining a phenolic adhesive for the wood industry modified with 3,3'-thiobis(1-(2-(3-chloro-2-hydroxy-propyl)thioethyl)-2,2'-bis(3-chloro-2-hydroxy-propyl)thiopropyl sulfide.

[0086] The steps of preparing reconstituted wood by using 3,3'-thiobis(1-(2-(3-chloro-2-hydroxy-propyl)thioethyl)-2,2'-bis(3-chloro-2-hydroxy-propyl)thiopropyl sulfide modified wood industry adhesive are as follows:

[0087] (a) Add 1.2 kg of veneer into a 10 L reactor and keep it under vacuum at -0.4 MPa for 0.5 h;

[0088] (b) adding 10 kg of 3,3'-thiobis(1-(2-(3-chloro-2-hydroxy-propyl)thioethyl)-2,2'-bis(3-chloro-2-hydroxy-propyl)thiopropyl sulfide modified phenolic adhesive for wood industry into a reaction kettle, and performing positive pressure impregnation at 0.6 MPa for 1 h;

[0089] (c) taking the wood out of the reactor, subjecting it to extrusion-leach-extrusion for a total of 4-5 minutes, and then air-drying it for 24 hours;

[0090] (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood. The temperature is programmed to cure at 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. The core layer temperature is tested to be maintained at 120°C for 2 hours and then naturally cooled to room temperature.

[0091] Example 4

[0092] The wood reconstitution agent of this embodiment is 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, and its preparation method is as follows:

[0093] Weigh 130.5 g of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol and 460 g of methanol solvent, stir evenly, then add 166.5 g of epichlorohydrin, continue stirring evenly, then add 6 g of 2% sodium hydroxide aqueous solution while stirring, control the system to react at 0°C, the reaction time is 20 hours, and the stirring speed is 450 r / min. The end point of the reaction is determined by high performance liquid chromatography content, and the end point is when the content of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol is less than 3%. Use a rotary evaporator to remove the solvent to obtain 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, and its liquid phase spectrum is as follows Figure 5 shown.

[0094] A wood industry adhesive with excellent water resistance comprises the following raw materials in parts by weight: 40 parts of a phenolic adhesive for the wood industry, 4 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, 36 parts of ethanol and 20 parts of water.

[0095] The preparation steps of the above-mentioned modified wood industry phenolic adhesive are as follows:

[0096] (a) adding 4 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane and 36 parts of ethanol into a reaction kettle and mixing them at room temperature for 30 minutes;

[0097] (b) adding 40 parts of phenolic adhesive for wood industry to step (a) and mixing for 30 minutes;

[0098] (c) adding 20 parts of water to step (b) to dilute the mixed solution, thereby obtaining a phenolic adhesive for wood industry modified with 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0099] The steps of preparing reconstituted wood by using 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified wood industrial adhesive are as follows:

[0100] (a) Add 1.2 kg of veneer into a 10 L reactor and keep it under vacuum at -0.4 MPa for 0.5 h;

[0101] (b) adding 10 kg of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified phenolic adhesive for wood industry into the reactor, and performing positive pressure impregnation at 0.6 MPa for 1 h;

[0102] (c) taking the wood out of the reactor, subjecting it to extrusion-leach-extrusion for a total of 4-5 minutes, and then air-drying it for 24 hours;

[0103] (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood. The temperature is programmed to cure at 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. The core layer temperature is tested to be maintained at 120°C for 2 hours and then naturally cooled to room temperature.

[0104] Example 5

[0105] The wood reconstitution agent of this embodiment is 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, and its preparation method is as follows:

[0106] Weigh 130.5 g of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol and 460 g of methanol solvent, stir evenly, add 166.5 g of epichlorohydrin, continue stirring evenly, add 6 g of 2% sodium hydroxide aqueous solution while stirring, control the system to react at 0°C, the reaction time is 20 hours, and the stirring speed is 450 r / min. The end point of the reaction is determined by high performance liquid chromatography content, and the end point is when the content of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol is less than 3%. Use a rotary evaporator to remove the solvent to obtain 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0107] A wood industry adhesive with excellent water resistance comprises the following raw materials in parts by weight: 40 parts of a phenolic adhesive for the wood industry, 4 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, 36 parts of ethanol and 20 parts of water.

[0108] The preparation steps of the above-mentioned modified wood industry phenolic adhesive are as follows:

[0109] (a) adding 4 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane and 36 parts of ethanol into a reaction kettle and mixing them at room temperature for 30 minutes;

[0110] (b) adding 40 parts of phenolic adhesive for wood industry to step (a) and mixing for 30 minutes;

[0111] (c) adding 20 parts of water to step (b) to dilute the mixed solution, thereby obtaining a phenolic adhesive for wood industry modified with 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0112] The steps of preparing reconstituted wood by using 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified wood industrial adhesive are as follows:

[0113] (a) Add 1.2 kg of veneer into a 10 L reactor;

[0114] (b) adding 10 kg of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified phenolic adhesive for wood industry into a reaction kettle, and performing normal pressure impregnation for 24 hours;

[0115] (c) taking the wood out of the reactor, subjecting it to extrusion-leach-extrusion for a total of 4-5 minutes, and then air-drying it for 24 hours;

[0116] (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood. The temperature is programmed to cure at 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. The core layer temperature is tested to be maintained at 120°C for 2 hours and then naturally cooled to room temperature.

[0117] Example 6

[0118] The wood reconstitution agent of this embodiment is 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, and its preparation method is as follows:

[0119] Weigh 130.5 g of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol and 460 g of methanol solvent, stir evenly, add 166.5 g of epichlorohydrin, continue stirring evenly, add 6 g of 2% sodium hydroxide aqueous solution while stirring, control the system to react at 0°C, the reaction time is 20 hours, and the stirring speed is 450 r / min. The end point of the reaction is determined by high performance liquid chromatography content, and the end point is when the content of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol is less than 3%. Use a rotary evaporator to remove the solvent to obtain 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0120] A wood industry adhesive with excellent water resistance comprises the following raw materials in parts by weight: 48.6954 parts of a phenolic adhesive for the wood industry, 0.0001 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, 12 parts of ethanol, and 39.3045 parts of water.

[0121] The preparation steps of the above-mentioned modified wood industry phenolic adhesive are as follows:

[0122] (a) adding 0.0001 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane and 12 parts of ethanol into a reaction kettle and mixing them at room temperature for 30 minutes;

[0123] (b) adding 48.6954 parts of phenolic adhesive for wood industry to step (a) and mixing for 30 minutes;

[0124] (c) adding 39.3045 parts of water to step (b) to dilute the mixed solution, thereby obtaining a phenolic adhesive for wood industry modified with 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0125] The steps of preparing reconstituted wood by using 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified wood industrial adhesive are as follows:

[0126] (a) Add 1.2 kg of veneer into a 10 L reactor and keep it under vacuum at -0.4 MPa for 0.5 h;

[0127] (b) adding 10 kg of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified phenolic adhesive for wood industry into the reactor, and performing positive pressure impregnation at 0.6 MPa for 1 h;

[0128] (c) taking the wood out of the reactor, subjecting it to extrusion-leach-extrusion for a total of 4-5 minutes, and then air-drying it for 24 hours;

[0129] (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood. The temperature is programmed to cure at 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. The core layer temperature is tested to be maintained at 120°C for 2 hours and then naturally cooled to room temperature.

[0130] Example 7

[0131] The wood reconstitution agent of this embodiment is 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, and its preparation method is as follows:

[0132] Weigh 130.5 g of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol and 460 g of methanol solvent, stir evenly, add 166.5 g of epichlorohydrin, continue stirring evenly, add 6 g of 2% sodium hydroxide aqueous solution while stirring, control the system to react at 0°C, the reaction time is 20 hours, and the stirring speed is 450 r / min. The end point of the reaction is determined by high performance liquid chromatography content, and the end point is when the content of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol is less than 3%. Use a rotary evaporator to remove the solvent to obtain 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0133] A wood industry adhesive with excellent water resistance comprises the following raw materials in parts by weight: 26.9565 parts of a phenolic adhesive for the wood industry, 10 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, 48 parts of ethanol, and 15.0435 parts of water.

[0134] The preparation steps of the above-mentioned modified wood industry phenolic adhesive are as follows:

[0135] (a) adding 10 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane and 48 parts of ethanol into a reaction kettle and mixing them at room temperature for 30 minutes;

[0136] (b) adding 26.9565 parts of phenolic adhesive for wood industry to step (a) and mixing for 30 minutes;

[0137] (c) adding 15.0435 parts of water to step (b) to dilute the mixture, thereby obtaining a phenolic adhesive for wood industry modified with 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0138] The steps of preparing reconstituted wood by using 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified wood industrial adhesive are as follows:

[0139] (a) Add 1.2 kg of veneer into a 10 L reactor and keep it under vacuum at -0.4 MPa for 0.5 h;

[0140] (b) adding 10 kg of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified phenolic adhesive for wood industry into the reactor, and performing positive pressure impregnation at 0.6 MPa for 1 h;

[0141] (c) taking the wood out of the reactor, subjecting it to extrusion-leach-extrusion for a total of 4-5 minutes, and then air-drying it for 24 hours;

[0142] (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood. The temperature is programmed to cure at 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. The core layer temperature is tested to be maintained at 120°C for 2 hours and then naturally cooled to room temperature.

[0143] Example 8

[0144] The wood reconstitution agent of this embodiment is epichlorohydrin disubstituted PEG-200 (DEPEG-200), and its preparation method is as follows:

[0145] Weigh 200g of PEG-200 and 578g of methanol solvent, stir evenly, add 185.04g of epichlorohydrin, continue to stir evenly, add 7.7g of 2% sodium hydroxide aqueous solution while stirring, control the system to react at 0°C, the reaction time is 20 hours, and the stirring speed is 450r / min. The end point of the reaction is determined by high performance liquid chromatography content, and the end point is when the content of PEG-200 is less than 3%. The solvent is removed by a rotary evaporator to obtain epichlorohydrin disubstituted PEG-200.

[0146] The invention discloses an adhesive for wood industry with excellent water resistance, comprising the following raw materials in parts by weight: 46.52 parts of phenolic adhesive for wood industry, 1 part of epichlorohydrin disubstituted PEG-200, 20 parts of ethanol and 32.48 parts of water.

[0147] The preparation steps of the above-mentioned modified wood industry phenolic adhesive are as follows:

[0148] (a) adding 1 part of epichlorohydrin disubstituted PEG-200 and 20 parts of ethanol into a reaction kettle and mixing them at room temperature for 30 minutes;

[0149] (b) adding 46.52 parts of phenolic adhesive for wood industry to step (a) and mixing for 30 minutes;

[0150] (c) adding 52.48 parts of water and 32.48 parts of water to the mixture of step (b) to dilute the mixture, thereby obtaining an epichlorohydrin disubstituted PEG-200 modified phenolic adhesive for wood industry.

[0151] The steps for preparing reconstituted wood by using epichlorohydrin disubstituted PEG-200 modified wood industrial adhesive are as follows:

[0152] (a) Add 1.2 kg of veneer into a 10 L reactor and keep it under vacuum at -0.4 MPa for 0.5 h;

[0153] (b) adding 10 kg of epichlorohydrin disubstituted PEG-200 modified phenolic adhesive for wood industry into the reactor, and performing positive pressure immersion at 0.6 MPa for 1 h;

[0154] (c) taking the wood out of the reactor, subjecting it to extrusion-leach-extrusion for a total of 4-5 minutes, and then air-drying it for 24 hours;

[0155] (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood. The temperature is programmed to cure at 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. The core layer temperature is tested to be maintained at 120°C for 2 hours and then naturally cooled to room temperature.

[0156] Example 9

[0157] The wood reconstitution agent of this embodiment is 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, and its preparation method is as follows:

[0158] Weigh 130.5 g of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol and 460 g of methanol solvent, stir evenly, add 166.5 g of epichlorohydrin, continue stirring evenly, add 6 g of 2% sodium hydroxide aqueous solution while stirring, control the system to react at 0°C, the reaction time is 20 hours, and the stirring speed is 450 r / min. The end point of the reaction is determined by high performance liquid chromatography content, and the end point is when the content of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol is less than 3%. Use a rotary evaporator to remove the solvent to obtain 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0159] A wood industry adhesive with excellent water resistance comprises the following raw materials in parts by weight: 40 parts of an epoxy resin adhesive for the wood industry, 4 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, 36 parts of ethanol, and 20 parts of water.

[0160] The preparation steps of the above modified wood industrial epoxy resin adhesive are as follows:

[0161] (a) adding 4 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane and 36 parts of ethanol into a reaction kettle and mixing them at room temperature for 30 minutes;

[0162] (b) adding 40 parts of epoxy resin adhesive for wood industry to step (a) and mixing for 30 minutes;

[0163] (c) adding 20 parts of water to step (b) to dilute the mixed solution, thereby obtaining an epoxy resin adhesive for wood industry modified with 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0164] The steps of preparing reconstituted wood by using 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified epoxy resin adhesive for wood industry are as follows:

[0165] (a) Add 1.2 kg of veneer into a 10 L reactor and keep it under vacuum at -0.4 MPa for 0.5 h;

[0166] (b) 10 kg of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified epoxy resin adhesive for wood industry was added into the reactor and positive pressure impregnation was performed at 0.6 MPa for 1 h;

[0167] (c) taking the wood out of the reactor, subjecting it to extrusion-leach-extrusion for a total of 4-5 minutes, and then air-drying it for 24 hours;

[0168] (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood. The temperature is programmed to cure at 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. The core layer temperature is tested to be maintained at 120°C for 2 hours and then naturally cooled to room temperature.

[0169] Example 10

[0170] The wood reconstitution agent of this embodiment is 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, and its preparation method is as follows:

[0171] Weigh 130.5 g of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol and 460 g of methanol solvent, stir evenly, add 166.5 g of epichlorohydrin, continue stirring evenly, add 6 g of 2% sodium hydroxide aqueous solution while stirring, control the system to react at 0°C, the reaction time is 20 hours, and the stirring speed is 450 r / min. The end point of the reaction is determined by high performance liquid chromatography content, and the end point is when the content of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol is less than 3%. Use a rotary evaporator to remove the solvent to obtain 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0172] An adhesive for the wood industry with excellent water resistance, comprising the following raw materials in parts by weight: 40 parts of urea-formaldehyde resin adhesive for the wood industry, 4 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, 36 parts of ethanol, and 20 parts of water;

[0173] The preparation steps of the above-mentioned modified wood industrial urea-formaldehyde resin adhesive are as follows:

[0174] (a) adding 4 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane and 36 parts of ethanol into a reaction kettle and mixing them for 30 minutes;

[0175] (b) adding 40 parts of urea-formaldehyde resin adhesive for wood industry to step (a) and mixing for 30 minutes;

[0176] (c) adding 20 parts of water to step (b) to dilute the mixed solution, thereby obtaining a urea-formaldehyde resin adhesive for wood industry modified with 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0177] The steps of preparing reconstituted wood by using 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified urea-formaldehyde resin adhesive for wood industry are as follows:

[0178] (a) Add 1.2 kg of veneer into a 10 L reactor and keep it under vacuum at -0.4 MPa for 0.5 h;

[0179] (b) adding 10 kg of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified urea-formaldehyde resin adhesive for wood industry into the reactor, and performing positive pressure impregnation at 0.6 MPa for 1 h;

[0180] (c) taking the wood out of the reactor, subjecting it to extrusion-leach-extrusion for a total of 4-5 minutes, and then air-drying it for 24 hours;

[0181] (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood. The temperature is programmed to cure at 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. The core layer temperature is tested to be maintained at 120°C for 2 hours and then naturally cooled to room temperature.

[0182] Comparative Example 1

[0183] An adhesive for the wood industry comprises the following raw materials in parts by weight: 48.69 parts of phenolic adhesive for the wood industry and 51.31 parts of water.

[0184] The preparation steps of the phenolic adhesive for wood industry of this embodiment are as follows:

[0185] 48.69 parts of phenolic adhesive for wood industry and 51.31 parts of water were added into a reaction kettle for mixing and dilution, so as to obtain the desired diluted phenolic adhesive for wood industry.

[0186] The steps for preparing recombinant wood are as follows:

[0187] (a) Add 1.2 kg of veneer into a 10 L reactor and keep it under vacuum at -0.4 MPa for 0.5 h;

[0188] (b) adding 10 kg of the diluted phenolic adhesive for wood industry into the reactor and performing positive pressure impregnation at 0.6 MPa for 1 h;

[0189] (c) taking the wood out of the reactor, subjecting it to extrusion-leach-extrusion for a total of 4-5 minutes, and then air-drying it for 24 hours;

[0190] (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood. The temperature is programmed to cure at 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. The core layer temperature is tested to be maintained at 120°C for 2 hours and then naturally cooled to room temperature.

[0191] Comparative Example 2

[0192] The wood reconstitution agent of this comparative example is 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, and its preparation method is as follows:

[0193] Weigh 130.5 g of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol and 460 g of methanol solvent, stir evenly, add 166.5 g of epichlorohydrin, continue stirring evenly, add 6 g of 2% sodium hydroxide aqueous solution while stirring, control the system to react at 0°C, the reaction time is 20 hours, and the stirring speed is 450 r / min. The end point of the reaction is determined by high performance liquid chromatography content, and the end point is when the content of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol is less than 3%. Use a rotary evaporator to remove the solvent to obtain 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0194] A wood industry adhesive with excellent water resistance comprises the following raw materials in parts by weight: 48.69555 parts of a phenolic adhesive for the wood industry, 0.00005 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, 8 parts of ethanol, and 43.3044 parts of water.

[0195] The preparation steps of the above-mentioned modified wood industry phenolic adhesive are as follows:

[0196] (a) adding 0.00005 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane and 8 parts of ethanol into a reaction kettle and mixing them at room temperature for 30 minutes;

[0197] (b) adding 48.69555 parts of phenolic adhesive for wood industry to step (a) and mixing for 30 min;

[0198] (c) adding 43.3044 parts of water to step (b) to dilute the mixture, thereby obtaining a phenolic adhesive for wood industry modified with 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0199] The steps of preparing reconstituted wood by using 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified wood industrial adhesive are as follows:

[0200] (a) Add 1.2 kg of veneer into a 10 L reactor and keep it under vacuum at -0.4 MPa for 0.5 h;

[0201] (b) adding 10 kg of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified phenolic adhesive for wood industry into the reactor, and performing positive pressure impregnation at 0.6 MPa for 1 h;

[0202] (c) The wood in the reactor is taken out, and subjected to extrusion-leach-extrusion for a total of 4-5 minutes, followed by air drying for 24 hours; (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood, and the temperature is programmed to rise for curing, 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. The core layer temperature is tested to be maintained at 120°C for 2 hours, and then naturally cooled to room temperature.

[0203] Comparative Example 3

[0204] The wood reconstitution agent of this comparative example is 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, and its preparation method is as follows:

[0205] Weigh 130.5 g of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol and 460 g of methanol solvent, stir evenly, add 166.5 g of epichlorohydrin, continue stirring evenly, add 6 g of 2% sodium hydroxide aqueous solution while stirring, control the system to react at 0°C, the reaction time is 20 hours, and the stirring speed is 450 r / min. The end point of the reaction is determined by high performance liquid chromatography content, and the end point is when the content of 2,3-bis(2-mercaptoethylthio)-3-propane-1-thiol is less than 3%. Use a rotary evaporator to remove the solvent to obtain 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0206] A wood industry adhesive with excellent water resistance comprises the following raw materials in parts by weight: 22.6087 parts of wood industry phenolic adhesive, 12 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, 52 parts of ethanol and 13.3913 parts of water.

[0207] The preparation steps of the above-mentioned modified wood industry phenolic adhesive are as follows:

[0208] (a) adding 12 parts of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane and 52 parts of ethanol into a reaction kettle and mixing them at room temperature for 30 minutes;

[0209] (b) adding 22.6087 parts of phenolic adhesive for wood industry to step (a) and mixing for 30 minutes;

[0210] (c) adding 13.3913 parts of water to step (b) to dilute the mixture, thereby obtaining a phenolic adhesive for wood industry modified with 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

[0211] The steps of preparing reconstituted wood by using 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified wood industrial adhesive are as follows:

[0212] (a) Add 1.2 kg of veneer into a 10 L reactor and keep it under vacuum at -0.4 MPa for 0.5 h;

[0213] (b) adding 10 kg of 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane modified phenolic adhesive for wood industry into the reactor, and performing positive pressure impregnation at 0.6 MPa for 1 h;

[0214] (c) The wood in the reactor is taken out, and subjected to extrusion-leach-extrusion for a total of 4-5 minutes, followed by air drying for 24 hours; (d) The impregnated veneer is cured by cold pressing to prepare reconstituted wood, and the temperature is programmed to rise for curing, 100°C for 1 hour, 120°C for 2 hours, and 140°C for 4 hours. The core layer temperature is tested to be maintained at 120°C for 2 hours, and then naturally cooled to room temperature.

[0215] Experimental example:

[0216] The properties of the reconstituted wood prepared by the reconstituted agent modified wood industrial adhesive provided in Examples 1-10 and Comparative Examples 1-3 were tested respectively; the parallel loading strength and vertical loading strength were tested using a 3365 universal tensile testing machine from Instron, USA; the anti-aging performance was tested using a BD / ZN-P ultraviolet lamp from Zhongke Boda Technology Co., Ltd.; and the fluorescence analysis was tested using a Zeiss Axio Scope A1 fluorescence microscope from Germany. The relevant performance test results are shown in Tables 1 and Figure 1-4 shown.

[0217] Table 1 Performance data of reconstituted wood prepared in Examples and Comparative Examples

[0218]

[0219]

[0220] As can be seen from Table 1, the reconstituted wood prepared by the reconstituted agent modified wood industry adhesive provided in Examples 1-10 of the present invention has excellent mechanical properties and better anti-aging properties. Although Comparative Examples 2 and 3 use the same reconstituted agent as in the examples, the amount of the reconstituted agent used is too small or too large, and the application effect is not achieved, resulting in poor performance of the reconstituted wood.

[0221] The following conclusions can be drawn from Table 1: (1) After being placed under ultraviolet light for one month, the color of the reconstituted wood sample prepared by using wood reconstituter to modify the wood industry adhesive is lighter than that of the reconstituted wood sample prepared by using unmodified wood industry adhesive, and the color is closer to the original wood color, indicating that the addition of wood reconstituter improves the anti-aging performance of wood industry adhesive; (2) The internal bonding strength of the reconstituted wood sample prepared by using wood reconstituter to modify the wood industry adhesive is higher than that of the reconstituted wood sample prepared by using unmodified wood industry adhesive, indicating that the addition of wood reconstituter improves the bonding strength of wood industry adhesive; (3) The water absorption and expansion rate of the reconstituted wood sample prepared by using wood reconstituter to modify the wood industry adhesive is lower than that of the reconstituted wood sample prepared by using unmodified wood industry adhesive, indicating that the addition of wood reconstituter improves the dimensional stability of the reconstituted wood prepared by using wood industry adhesive.

[0222] The technical features of the above-described embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above implementation case description can be used to help understand the principles and methods of the present invention. However, the above implementation case is not unique and should not be construed as a limitation of the present invention. At the same time, for those of ordinary skill in the art, according to the principles and methods of the present invention, flexible changes can be made in specific implementation methods and application scopes.

Claims

1. Use of a wood reorganization agent in the preparation of an adhesive for the wood industry, characterized in that: The modified adhesive for wood industry comprises 20-60 parts of adhesive for wood industry, 0.1-50 parts of alcohol, 10-60 parts of water and 0.01%-10% of wood reconstructor by weight of the modified adhesive for wood industry; the adhesive for wood industry is selected from one of phenolic resin, epoxy resin and urea-formaldehyde resin, and the wood reconstructor has the following structure: Where n=1-4, R is one or more of the following structures: Wherein R1, R2, R3 and R4 are C1-C5 alkane groups, and R5 is C1-C1000 alkane group.

2. The use of the wood reorganization agent according to claim 1 in the preparation of an adhesive for the wood industry, characterized in that: The wood reconstructor is selected from one of pentaerythritol tetrakis(3-(3-chloro-2-hydroxy-propylthio)propionate, 3,3'-((thiobis(ethane-2,1-diyl))bis(1-chloropropane-2-ol), 3,3'-thiobis(1-(2-(3-chloro-2-hydroxy-propyl)thioethyl)-2,2'-bis(3-chloro-2-hydroxy-propyl)thiopropyl sulfide, 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane, and epichlorohydrin disubstituted PEG-200.

3. The use of the wood reorganization agent according to claim 2 in the preparation of an adhesive for the wood industry, characterized in that: The wood restructurer is selected from 2,3-bis(2-(3-chloro-2-hydroxy-propylthio)ethylthio)-1-(3-chloro-2-hydroxy-propyl)thiopropane.

4. The use of the wood reorganization agent according to claim 1 in the preparation of an adhesive for the wood industry, characterized in that: The alcohol is selected from one or more of methanol, ethanol, propylene glycol, n-butanol, isobutanol and ethylene glycol.

5. The use of the wood reorganization agent according to claim 1 in the preparation of an adhesive for the wood industry, characterized in that: The preparation method of the modified adhesive for wood industry comprises the following specific steps: (a) adding a wood reorganization agent and alcohol into a reaction kettle and mixing them at room temperature for 30 minutes; (b) adding a wood industry adhesive to the mixture in step (a), and mixing with mechanical stirring for 30 minutes; (c) adding pure water to the mixture obtained in step (b) to make the content of the wood industry adhesive in the final mixture reach 16wt%-30wt%, that is, obtaining a modified wood industry adhesive with excellent water resistance in a uniform solution state.

6. The modified wood industrial adhesive prepared by using the wood reorganization agent according to claim 1, characterized in that: The composition is 20-60 parts of wood industry adhesive, 0.1-50 parts of alcohol, 10-60 parts of water and 0.01%-10% of wood reconstructor accounting for the weight of the modified wood industry adhesive. The wood industry adhesive is selected from one of phenolic resin, epoxy resin and urea-formaldehyde resin.

7. Reconstructed wood prepared using the modified wood industrial adhesive according to claim 6.

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