CN115386320A - Isocyanate-coated aldehyde-free adhesive and application thereof - Google Patents
Isocyanate-coated aldehyde-free adhesive and application thereof Download PDFInfo
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- CN115386320A CN115386320A CN202211173376.3A CN202211173376A CN115386320A CN 115386320 A CN115386320 A CN 115386320A CN 202211173376 A CN202211173376 A CN 202211173376A CN 115386320 A CN115386320 A CN 115386320A
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- Prior art keywords
- isocyanate
- dextrin
- modified
- free adhesive
- coating
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- Granted
Links
- 239000012948 isocyanate Substances 0.000 title claims abstract description 68
- 150000002513 isocyanates Chemical class 0.000 title claims abstract description 66
- 239000000853 adhesive Substances 0.000 title claims abstract description 36
- 230000001070 adhesive effect Effects 0.000 title claims abstract description 36
- 229920001353 Dextrin Polymers 0.000 claims abstract description 57
- 239000004375 Dextrin Substances 0.000 claims abstract description 57
- 235000019425 dextrin Nutrition 0.000 claims abstract description 57
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims abstract description 48
- 238000000576 coating method Methods 0.000 claims abstract description 38
- 239000011120 plywood Substances 0.000 claims abstract description 37
- 239000011248 coating agent Substances 0.000 claims abstract description 31
- 239000011550 stock solution Substances 0.000 claims abstract description 21
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 20
- 239000000243 solution Substances 0.000 claims abstract description 18
- GOOHAUXETOMSMM-UHFFFAOYSA-N Propylene oxide Chemical compound CC1CO1 GOOHAUXETOMSMM-UHFFFAOYSA-N 0.000 claims abstract description 16
- 238000000034 method Methods 0.000 claims abstract description 14
- -1 polyoxyethylene Polymers 0.000 claims abstract description 13
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 10
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims abstract description 9
- 239000003755 preservative agent Substances 0.000 claims abstract description 5
- 230000002335 preservative effect Effects 0.000 claims abstract description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000002994 raw material Substances 0.000 claims abstract description 3
- 238000003825 pressing Methods 0.000 claims description 24
- 238000007731 hot pressing Methods 0.000 claims description 22
- 238000002360 preparation method Methods 0.000 claims description 15
- 238000007493 shaping process Methods 0.000 claims description 12
- 238000004513 sizing Methods 0.000 claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- UPMLOUAZCHDJJD-UHFFFAOYSA-N 4,4'-Diphenylmethane Diisocyanate Chemical compound C1=CC(N=C=O)=CC=C1CC1=CC=C(N=C=O)C=C1 UPMLOUAZCHDJJD-UHFFFAOYSA-N 0.000 claims description 7
- GEHJYWRUCIMESM-UHFFFAOYSA-L sodium sulfite Chemical compound [Na+].[Na+].[O-]S([O-])=O GEHJYWRUCIMESM-UHFFFAOYSA-L 0.000 claims description 6
- CHHHXKFHOYLYRE-UHFFFAOYSA-M 2,4-Hexadienoic acid, potassium salt (1:1), (2E,4E)- Chemical compound [K+].CC=CC=CC([O-])=O CHHHXKFHOYLYRE-UHFFFAOYSA-M 0.000 claims description 3
- 229940043351 ethyl-p-hydroxybenzoate Drugs 0.000 claims description 3
- NUVBSKCKDOMJSU-UHFFFAOYSA-N ethylparaben Chemical compound CCOC(=O)C1=CC=C(O)C=C1 NUVBSKCKDOMJSU-UHFFFAOYSA-N 0.000 claims description 3
- 239000004302 potassium sorbate Substances 0.000 claims description 3
- 235000010241 potassium sorbate Nutrition 0.000 claims description 3
- 229940069338 potassium sorbate Drugs 0.000 claims description 3
- WXMKPNITSTVMEF-UHFFFAOYSA-M sodium benzoate Chemical compound [Na+].[O-]C(=O)C1=CC=CC=C1 WXMKPNITSTVMEF-UHFFFAOYSA-M 0.000 claims description 3
- 239000004299 sodium benzoate Substances 0.000 claims description 3
- 235000010234 sodium benzoate Nutrition 0.000 claims description 3
- 235000010265 sodium sulphite Nutrition 0.000 claims description 3
- ALQLPWJFHRMHIU-UHFFFAOYSA-N 1,4-diisocyanatobenzene Chemical compound O=C=NC1=CC=C(N=C=O)C=C1 ALQLPWJFHRMHIU-UHFFFAOYSA-N 0.000 claims description 2
- SBJCUZQNHOLYMD-UHFFFAOYSA-N 1,5-Naphthalene diisocyanate Chemical compound C1=CC=C2C(N=C=O)=CC=CC2=C1N=C=O SBJCUZQNHOLYMD-UHFFFAOYSA-N 0.000 claims description 2
- 239000005057 Hexamethylene diisocyanate Substances 0.000 claims description 2
- 239000005058 Isophorone diisocyanate Substances 0.000 claims description 2
- RRAMGCGOFNQTLD-UHFFFAOYSA-N hexamethylene diisocyanate Chemical compound O=C=NCCCCCCN=C=O RRAMGCGOFNQTLD-UHFFFAOYSA-N 0.000 claims description 2
- NIMLQBUJDJZYEJ-UHFFFAOYSA-N isophorone diisocyanate Chemical compound CC1(C)CC(N=C=O)CC(C)(CN=C=O)C1 NIMLQBUJDJZYEJ-UHFFFAOYSA-N 0.000 claims description 2
- 239000005056 polyisocyanate Substances 0.000 claims description 2
- 229920001228 polyisocyanate Polymers 0.000 claims description 2
- 229920006389 polyphenyl polymer Polymers 0.000 claims description 2
- 229960003885 sodium benzoate Drugs 0.000 claims description 2
- 239000004402 sodium ethyl p-hydroxybenzoate Substances 0.000 claims description 2
- 235000010226 sodium ethyl p-hydroxybenzoate Nutrition 0.000 claims description 2
- 229940001482 sodium sulfite Drugs 0.000 claims description 2
- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical compound CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 claims description 2
- GYHFUZHODSMOHU-UHFFFAOYSA-N nonanal Chemical compound CCCCCCCCC=O GYHFUZHODSMOHU-UHFFFAOYSA-N 0.000 claims 2
- FKTHNVSLHLHISI-UHFFFAOYSA-N 1,2-bis(isocyanatomethyl)benzene Chemical compound O=C=NCC1=CC=CC=C1CN=C=O FKTHNVSLHLHISI-UHFFFAOYSA-N 0.000 claims 1
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 abstract description 4
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- 230000008569 process Effects 0.000 abstract description 4
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 33
- ODLHGICHYURWBS-LKONHMLTSA-N trappsol cyclo Chemical compound CC(O)COC[C@H]([C@H]([C@@H]([C@H]1O)O)O[C@H]2O[C@@H]([C@@H](O[C@H]3O[C@H](COCC(C)O)[C@H]([C@@H]([C@H]3O)O)O[C@H]3O[C@H](COCC(C)O)[C@H]([C@@H]([C@H]3O)O)O[C@H]3O[C@H](COCC(C)O)[C@H]([C@@H]([C@H]3O)O)O[C@H]3O[C@H](COCC(C)O)[C@H]([C@@H]([C@H]3O)O)O3)[C@H](O)[C@H]2O)COCC(O)C)O[C@@H]1O[C@H]1[C@H](O)[C@@H](O)[C@@H]3O[C@@H]1COCC(C)O ODLHGICHYURWBS-LKONHMLTSA-N 0.000 description 9
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 8
- 238000010008 shearing Methods 0.000 description 8
- 239000003292 glue Substances 0.000 description 7
- PLFFHJWXOGYWPR-HEDMGYOXSA-N (4r)-4-[(3r,3as,5ar,5br,7as,11as,11br,13ar,13bs)-5a,5b,8,8,11a,13b-hexamethyl-1,2,3,3a,4,5,6,7,7a,9,10,11,11b,12,13,13a-hexadecahydrocyclopenta[a]chrysen-3-yl]pentan-1-ol Chemical compound C([C@]1(C)[C@H]2CC[C@H]34)CCC(C)(C)[C@@H]1CC[C@@]2(C)[C@]4(C)CC[C@@H]1[C@]3(C)CC[C@@H]1[C@@H](CCCO)C PLFFHJWXOGYWPR-HEDMGYOXSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 4
- 238000010561 standard procedure Methods 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 239000002023 wood Substances 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 238000003892 spreading Methods 0.000 description 3
- 230000007480 spreading Effects 0.000 description 3
- 238000006467 substitution reaction Methods 0.000 description 3
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229920000858 Cyclodextrin Polymers 0.000 description 1
- 239000001116 FEMA 4028 Substances 0.000 description 1
- 229920001807 Urea-formaldehyde Polymers 0.000 description 1
- 239000008186 active pharmaceutical agent Substances 0.000 description 1
- 238000004026 adhesive bonding Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 235000011175 beta-cyclodextrine Nutrition 0.000 description 1
- 229960004853 betadex Drugs 0.000 description 1
- 125000003636 chemical group Chemical group 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000004403 ethyl p-hydroxybenzoate Substances 0.000 description 1
- 235000010228 ethyl p-hydroxybenzoate Nutrition 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- ODGAOXROABLFNM-UHFFFAOYSA-N polynoxylin Chemical compound O=C.NC(N)=O ODGAOXROABLFNM-UHFFFAOYSA-N 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000010902 straw Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J105/00—Adhesives based on polysaccharides or on their derivatives, not provided for in groups C09J101/00 or C09J103/00
- C09J105/16—Cyclodextrin; Derivatives thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27D—WORKING VENEER OR PLYWOOD
- B27D1/00—Joining wood veneer with any material; Forming articles thereby; Preparatory processing of surfaces to be joined, e.g. scoring
- B27D1/04—Joining wood veneer with any material; Forming articles thereby; Preparatory processing of surfaces to be joined, e.g. scoring to produce plywood or articles made therefrom; Plywood sheets
- B27D1/08—Manufacture of shaped articles; Presses specially designed therefor
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
- C09J11/08—Macromolecular additives
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Wood Science & Technology (AREA)
- Forests & Forestry (AREA)
- Veneer Processing And Manufacture Of Plywood (AREA)
Abstract
The invention relates to the technical field of artificial board production, in particular to an isocyanate-coated aldehyde-free adhesive and application thereof, wherein the isocyanate-coated aldehyde-free adhesive comprises the following raw materials in parts by weight: 100 parts of coating modified dextrin stock solution, 5-15 parts of modified isocyanate and 1-10 parts of preservative; the modified dextrin stock solution for coating is prepared by introducing nitrogen into a dextrin solution and adding epoxypropane and sodium hydroxide; the modified isocyanate is obtained by reacting isocyanate and polyoxyethylene alcohol. The invention uses the method of modified dextrin coating to protect isocyanate groups, and the produced isocyanate-coated aldehyde-free adhesive has enough high bonding strength and the working life can reach 6 to 8 hours, thereby meeting the production requirements of plywood by the original process and equipment of plywood factories.
Description
Technical Field
The invention relates to the technical field of artificial board production, in particular to an isocyanate-coated aldehyde-free adhesive and application thereof.
Background
The plywood can improve the utilization rate of the wood and is a main way for saving the wood. The adhesive for the traditional plywood-based panel is mainly urea-formaldehyde glue (UF), and the adhesive can release formaldehyde which is harmful to human bodies. With the improvement of environmental awareness of people, an environment-friendly artificial board without formaldehyde is needed to improve the health and the quality of life of people.
In recent years, aldehyde-free isocyanate adhesives have become more widely used. Besides containing no formaldehyde, the isocyanate has many advantages, such as high bonding strength, high curing speed, relaxed requirements on water content of wood/straw materials, excellent board physical properties and the like. Chinese patent CN10524857A invented an aldehyde-free plywood prepared by adopting an isocyanate spraying sizing method, but the original process equipment needs to be modified. When the waterborne polymer-isocyanate wood adhesive (API for short) is used, the compound isocyanate is required to be used as a curing agent. Because the chemical property of the isocyanate group (-NCO) is very active, the isocyanate group (-NCO) is very easy to react with water and substances containing active hydrogen, the active period is short, and the requirements of technological operation cannot be met.
Disclosure of Invention
Aiming at the problem of short working life of isocyanate formaldehyde-free adhesives, the invention provides an isocyanate formaldehyde-free adhesive and application thereof, which have the advantages of high bonding strength and long working life and can be used for producing plywood by using the original process and equipment of plywood factories.
In a first aspect, the invention provides an isocyanate-coated aldehyde-free adhesive, which comprises the following raw materials in parts by mass:
100 parts of modified dextrin stock solution for coating;
5-15 parts of modified isocyanate;
1-10 parts of a preservative;
the modified dextrin stock solution for coating is prepared by introducing nitrogen into a dextrin solution and adding epoxypropane and sodium hydroxide;
the modified isocyanate is obtained by reacting isocyanate and polyoxyethylene alcohol.
Nitrogen is bubbled through the dextrin solution and propylene oxide and sodium hydroxide are added to produce hydroxypropyl beta-cyclodextrin. A plurality of hydroxyl groups are distributed on the outer side edge of the cavity of the hydroxypropyl beta-cyclodextrin molecule, so that the outer wall of the hydroxypropyl beta-cyclodextrin molecule has strong hydrophilicity; the inner cavity of the hydroxyl beta-cyclodextrin is composed of hydrogen atoms on carbon atoms at 3 and 5 positions and oxygen atoms on carbon atoms at 4 positions, so that the hydroxypropyl beta-cyclodextrin molecular cavity presents relative hydrophobicity. Therefore, the hydroxypropyl beta-cyclodextrin has an external hydrophilic and internal hydrophobic special cavity structure and can be used as a main body of the inclusion compound.
The isocyanate molecules all contain benzene rings, have strong hydrophobicity, form modified isocyanate molecules by modifying the isocyanate, provide driving force for entering cavities of the hydroxypropyl beta-cyclodextrin, and can be used as an object of the inclusion compound.
And part or all of the modified isocyanate molecules enter the hydroxypropyl beta-cyclodextrin cavity to replace water molecules in the hydroxypropyl beta-cyclodextrin cavity, so that the inclusion is completed. The inclusion compound formed by utilizing the cavity of the hydroxypropyl beta-cyclodextrin can not only increase the solubility of modified isocyanate molecules, but also control the release of the modified isocyanate molecules, slow down the reaction of isocyanate (-NCO) and water and prolong the service life of the adhesive.
Further, the preparation method of the modified dextrin stock solution for coating comprises the following steps:
(1) Adding water into dextrin to prepare a dextrin solution with the mass concentration of 30-70%;
(2) Introducing nitrogen into the dextrin solution, adding epoxypropane and sodium hydroxide, reacting for 1-48 hours, and adjusting the pH value to 5-7 to obtain the modified dextrin stock solution.
Furthermore, the dosage of the propylene oxide is 1 to 10 percent of the mass of the dextrin, and the dosage of the sodium hydroxide is 0.5 to 1 percent of the mass of the dextrin.
Further, the preparation method of the modified isocyanate comprises the following steps:
10 parts by weight of isocyanate and 1 part by weight of polyoxyethylene alcohol with the molecular weight of 600-750 are uniformly mixed and react for 2 hours at the temperature of 75 ℃ to prepare the modified isocyanate.
Further, the isocyanate is one or more of diphenylmethane diisocyanate, 1, 5-naphthalene diisocyanate, tetramethyl diisocyanate, p-phenylene diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dimethylene phenyl diisocyanate and polymethylene polyphenyl polyisocyanate.
Further, the preservative is one or more of sodium benzoate, potassium sorbate, sodium sulfite and ethyl p-hydroxybenzoate.
In a second aspect, the invention provides an application of the isocyanate-coated formaldehyde-free adhesive in preparing plywood.
In a third aspect, the invention provides a method for preparing a plywood by coating the isocyanate formaldehyde-free adhesive, which comprises the following steps:
(1) Sizing: coating isocyanate non-formaldehyde adhesive on a single board by a double-sided coating method;
(2) Assembling: assembling the glued single boards according to the required board area and the number of the single board layers to obtain assembled board blanks;
(3) Cold pressing: putting the assembled plate blank into a press for cold pressing and shaping;
(4) Hot pressing: and (3) placing the cold-pressed and shaped plate blank for 2-8 hours, and then carrying out hot-press shaping at 120 ℃.
Further, the sizing amount of the sizing agent is 220-280 g/m 2 。
Further, the cold pressing pressure is 5-10 MPa, and the cold pressing time is 30-60 min.
Further, the hot pressing pressure is 1.5-2.5 MPa, and the hot pressing time is 0.8-2 min/mm.
The invention has the beneficial effects that:
the isocyanate-coated aldehyde-free adhesive provided by the invention uses a modified dextrin coating method to protect isocyanate groups, the working life can reach 6-8 hours, and the production requirements of plywood by the original process and equipment of a plywood factory are met.
Detailed Description
In order to make those skilled in the art better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the following examples, polymeric MDI was obtained from the Vanhua chemical group, inc., polyoxyethylene monol was obtained from Jiangsu Haian petrochemical plant, and other reagents were commercially available.
Example 1
1. Preparation of isocyanate-coated aldehyde-free adhesive
(1) Adding water into dextrin to prepare a dextrin solution with the mass concentration of 50%; introducing nitrogen into the dextrin solution, adding propylene oxide and sodium hydroxide, wherein the dosage of the propylene oxide is 5% of the mass of the dextrin, the dosage of the sodium hydroxide is 1% of the mass of the dextrin, reacting for 48 hours, and then adjusting the pH value to 5 by using hydrochloric acid to obtain the modified dextrin stock solution for coating.
(2) 10 parts by weight of polymeric MDI and 1 part by weight of polyoxyethylene monol with the molecular weight of 750 are mixed evenly and reacted for 2 hours at the temperature of 75 ℃ to prepare the modified isocyanate.
(3) Mixing 100 parts by weight of coating modified dextrin stock solution, 10 parts by weight of modified isocyanate and 1 part by weight of potassium sorbate, and uniformly stirring to obtain the isocyanate-coated formaldehyde-free adhesive.
2. Preparation of plywood
(1) Sizing: coating isocyanate non-formaldehyde adhesive on a single board by a double-sided coating method, wherein the coating amount is 250g/m 2 ；
(2) Assembling: assembling the glued single boards according to the required board area and the number of the single board layers to obtain assembled board blanks;
(3) Cold pressing: putting the assembled plate blank into a press for cold pressing and shaping, wherein the cold pressing pressure is 5MPa, and the cold pressing time is 60min;
(4) Hot pressing: and (3) respectively placing the cold-pressed and shaped plate blank for 2 hours, 4 hours and 6 hours, and then carrying out hot-pressing and shaping at the temperature of 120 ℃, wherein the hot-pressing pressure is 2MPa, and the hot-pressing time is 1.5min/mm.
When the veneer is glued by using the isocyanate-coated formaldehyde-free adhesive, the gluing is uniform; the formaldehyde emission of the produced plywood is 0.025mg/L; the method is characterized in that a standard method of a II-type plywood is used for detection, the shearing strength of the plywood produced by hot-press forming after the slab is placed for 2 hours, 4 hours and 6 hours is respectively 1.3MPa, 1.0MPa and 0.75MPa, and the standard of the II-type plywood (the standard value of the shearing strength of the II-type plywood is not less than 0.7 MPa) is met.
Example 2
1. Preparation of isocyanate-coated aldehyde-free adhesive
(1) Preparing a modified dextrin stock solution for coating:
adding water into dextrin to prepare a dextrin solution with the mass concentration of 50%; introducing nitrogen into the dextrin solution and adding propylene oxide and sodium hydroxide; the using amount of the propylene oxide is 10 percent of the mass of the dextrin, the using amount of the sodium hydroxide is 1 percent of the mass of the dextrin, and after 48 hours of reaction, the pH value is adjusted to 6 by hydrochloric acid, so as to obtain the modified dextrin stock solution for coating.
(2) Preparation of modified isocyanates
10 parts by weight of polymeric MDI and 1 part by weight of polyoxyethylene monol with the molecular weight of 600 are evenly mixed and reacted for 2 hours at the temperature of 75 ℃ to prepare the modified isocyanate.
(3) And (3) uniformly stirring 100 parts by weight of coating modified dextrin stock solution, 10 parts by weight of modified isocyanate and 10 parts by weight of sodium sulfite.
2. Preparation of plywood
(1) Sizing: coating isocyanate non-formaldehyde adhesive on a single board by a double-sided coating method, wherein the coating amount is 250g/m 2 ；
(2) Assembling: assembling the glued single boards according to the required board area and the number of the single board layers to obtain assembled board blanks;
(3) Cold pressing: putting the assembled plate blank into a press for cold pressing and shaping, wherein the cold pressing pressure is 5MPa, and the cold pressing time is 60min;
(4) Hot pressing: and (3) respectively placing the cold-pressed and shaped plate blank for 4 hours and 8 hours, and then carrying out hot-pressing and shaping at the temperature of 120 ℃, wherein the hot-pressing pressure is 2MPa, and the hot-pressing time is 1.5min/mm.
When the veneer is glued by using the glue spreading method in the embodiment 2, the glue is uniformly spread; formaldehyde emission of the produced plywood: 0.025mg/L; the method is characterized in that a II-type plywood standard method is used for detection, the shearing strength of the plywood produced by hot-press forming after the slab is placed for 4 hours and 8 hours is 0.95MPa and 0.7MPa respectively, and the II-type plywood standard is met (the standard value of the shearing strength of the II-type plywood is more than or equal to 0.7 MPa).
Example 3
1. Preparation of isocyanate-coated aldehyde-free adhesive
(1) Preparing a modified dextrin stock solution for coating:
adding water into dextrin to prepare a dextrin solution with the mass concentration of 30%; introducing nitrogen into the dextrin solution and adding epoxypropane and sodium hydroxide; the amount of the propylene oxide is 7 percent of the mass of the dextrin, the amount of the sodium hydroxide is 0.5 percent of the mass of the dextrin, and after 24 hours of reaction, the pH value is adjusted to 6 by hydrochloric acid, thus obtaining the modified dextrin stock solution for coating.
(2) Preparation of modified isocyanates
10 parts by weight of polymeric MDI and 1 part by weight of polyoxyethylene monol with the molecular weight of 750 are mixed evenly and reacted for 2 hours at the temperature of 75 ℃ to prepare the modified isocyanate.
(3) And (3) uniformly stirring 100 parts by weight of the coating modified dextrin stock solution, 5 parts by weight of modified isocyanate and 5 parts by weight of sodium benzoate.
2. Preparation of plywood
(1) Sizing: coating isocyanate non-formaldehyde adhesive on a single board by adopting a double-sided coating method, wherein the coating amount is 220g/m 2 ；
(2) Assembling: assembling the glued single boards according to the required board area and the number of the single board layers to obtain assembled board blanks;
(3) Cold pressing: putting the assembled plate blank into a press for cold pressing and shaping, wherein the cold pressing pressure is 7MPa, and the cold pressing time is 30min;
(4) Hot pressing: and (3) placing the cold-pressed and shaped plate blank for 6 hours, and then carrying out hot-pressing and shaping at the temperature of 120 ℃, wherein the hot-pressing pressure is 1.5MPa, and the hot-pressing time is 0.8min/mm.
When the veneer is glued by using the glue spreading agent in the embodiment 3, the glue is uniformly spread; formaldehyde emission of the produced plywood: 0.025mg/L; and (3) detecting by using a II-type plywood standard method, wherein the shearing strength of the plywood is 0.8MPa, and the II-type plywood standard is met (the standard value of the shearing strength of the II-type plywood is not less than 0.7 MPa).
Example 4
1. Preparation of isocyanate-coated aldehyde-free adhesive
(1) Preparing a modified dextrin stock solution for coating:
adding water into dextrin to prepare a dextrin solution with the mass concentration of 70%; introducing nitrogen into the dextrin solution and adding epoxypropane and sodium hydroxide; the amount of the propylene oxide is 8 percent of the mass of the dextrin, the amount of the sodium hydroxide is 0.8 percent of the mass of the dextrin, after 36 hours of reaction, the pH value is adjusted to 7 by hydrochloric acid, and modified dextrin stock solution for coating is obtained.
(2) Preparation of modified isocyanates
10 parts by weight of polymeric MDI and 1 part by weight of polyoxyethylene mono-alcohol with the molecular weight of 750 are evenly mixed and reacted for 2 hours at the temperature of 75 ℃ to prepare the modified isocyanate.
(3) And (3) uniformly stirring 100 parts by weight of coating modified dextrin stock solution, 15 parts by weight of modified isocyanate and 7 parts by weight of ethyl p-hydroxybenzoate.
2. Preparation of plywood
(1) Sizing: coating isocyanate non-formaldehyde adhesive on a single board by a double-sided coating method, wherein the coating amount is 280g/m 2 ；
(2) Assembling: assembling the glued single boards according to the required board area and the number of the single board layers to obtain assembled board blanks;
(3) Cold pressing: putting the assembled plate blank into a press for cold pressing and shaping, wherein the cold pressing pressure is 10MPa, and the cold pressing time is 45min;
(4) Hot pressing: and (3) placing the cold-pressed and shaped plate blank for 8 hours, and then carrying out hot-pressing and shaping at the temperature of 120 ℃, wherein the hot-pressing pressure is 2.5MPa, and the hot-pressing time is 2min/mm.
When the veneer is glued by using the glue spreading agent in the embodiment 4, the glue is uniformly spread; the formaldehyde emission of the produced plywood is as follows: 0.025mg/L; the detection is carried out by using a II-type plywood standard method, the shearing strength of the plywood is 1.25MPa, and the II-type plywood standard is met (the standard value of the shearing strength of the II-type plywood is not less than 0.7 MPa).
Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made on the embodiments of the present invention by those skilled in the art without departing from the spirit and scope of the present invention, and these modifications or substitutions are within the scope of the present invention/any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention.
Claims (10)
1. The isocyanate-coated aldehyde-free adhesive is characterized by comprising the following raw materials in parts by weight:
100 parts of modified dextrin stock solution for coating;
5-15 parts of modified isocyanate;
1-10 parts of a preservative;
the modified dextrin stock solution for coating is prepared by introducing nitrogen into a dextrin solution and adding epoxypropane and sodium hydroxide;
the modified isocyanate is obtained by reacting isocyanate and polyoxyethylene alcohol.
2. The isocyanate aldehyde-free adhesive according to claim 1, wherein the preparation method of the modified dextrin stock solution for coating comprises the following steps:
(1) Adding water into dextrin to prepare a dextrin solution with the mass concentration of 40-70%;
(2) Introducing nitrogen into the dextrin solution, adding epoxypropane and sodium hydroxide, reacting for 1-48 hours, and adjusting the pH value to 5-7 to obtain the modified dextrin stock solution.
3. The isocyanate non-aldehyde adhesive according to claim 2, wherein the propylene oxide is used in an amount of 5 to 10% by mass of the dextrin, and the sodium hydroxide is used in an amount of 0.5 to 1% by mass of the dextrin.
4. The isocyanate aldehyde-free adhesive of claim 1, wherein the isocyanate is one or more of diphenylmethane diisocyanate, 1, 5-naphthalene diisocyanate, tetramethyl diisocyanate, p-phenylene diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and polymethylene polyphenyl polyisocyanate.
5. The isocyanate aldehyde-free adhesive of claim 1, wherein the preservative is one or more of sodium benzoate, potassium sorbate, sodium sulfite, and ethyl p-hydroxybenzoate.
6. Use of the isocyanate-coated aldehyde-free adhesive of claim 1 in the preparation of plywood.
7. A method of producing plywood coated with an isocyanate formaldehyde-free adhesive according to claim 1 comprising the steps of:
(1) Sizing: coating isocyanate formaldehyde-free adhesive on a single board by adopting a double-sided coating method;
(2) Assembling: assembling the glued single boards according to the required board area and the number of the single board layers to obtain assembled board blanks;
(3) Cold pressing: putting the assembled plate blank into a press for cold pressing and shaping;
(4) Hot pressing: and (3) placing the cold-pressed and shaped plate blank for 2-8 hours, and then carrying out hot-press shaping at the temperature of 120-140 ℃.
8. The method of claim 7, wherein said sizing has a size of 220 to 280g/m 2 。
9. The method according to claim 7, wherein the cold pressing pressure is 5-10 MPa and the cold pressing time is 30-60 min.
10. The method of claim 7, wherein the hot pressing pressure is 1.5 to 2.5MPa and the hot pressing time is 0.8 to 2min/mm.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR910018408A (en) * | 1990-04-16 | 1991-11-30 | 원본미기재 | Cyclodextrin Coated Solid Substrates and Methods for Making the Same |
| CN106336835A (en) * | 2016-09-20 | 2017-01-18 | 中国科学院理化技术研究所 | Single-component formaldehyde-free adhesive for multilayer plate and application thereof |
| CN107573427A (en) * | 2017-10-19 | 2018-01-12 | 无锡甜丰食品有限公司 | A kind of preparation method of hydroxypropyl maltodextrin |
| CN108641673A (en) * | 2018-05-10 | 2018-10-12 | 北京盛大华源科技有限公司 | A kind of preparation method of plywood without formaldehyde release |
| CN112831036A (en) * | 2020-12-30 | 2021-05-25 | 中国林业科学研究院林业新技术研究所 | Plant glycosyl polyester adhesive as well as preparation method and application thereof |
| CN113831863A (en) * | 2020-06-24 | 2021-12-24 | 万华化学集团股份有限公司 | Adhesive, preparation and application thereof |
| CN114456739A (en) * | 2022-01-25 | 2022-05-10 | 杭州昭朗五金有限公司 | Formaldehyde-free glued jointed board and production process thereof |
-
2022
- 2022-09-26 CN CN202211173376.3A patent/CN115386320B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR910018408A (en) * | 1990-04-16 | 1991-11-30 | 원본미기재 | Cyclodextrin Coated Solid Substrates and Methods for Making the Same |
| CN106336835A (en) * | 2016-09-20 | 2017-01-18 | 中国科学院理化技术研究所 | Single-component formaldehyde-free adhesive for multilayer plate and application thereof |
| CN107573427A (en) * | 2017-10-19 | 2018-01-12 | 无锡甜丰食品有限公司 | A kind of preparation method of hydroxypropyl maltodextrin |
| CN108641673A (en) * | 2018-05-10 | 2018-10-12 | 北京盛大华源科技有限公司 | A kind of preparation method of plywood without formaldehyde release |
| CN113831863A (en) * | 2020-06-24 | 2021-12-24 | 万华化学集团股份有限公司 | Adhesive, preparation and application thereof |
| CN112831036A (en) * | 2020-12-30 | 2021-05-25 | 中国林业科学研究院林业新技术研究所 | Plant glycosyl polyester adhesive as well as preparation method and application thereof |
| CN114456739A (en) * | 2022-01-25 | 2022-05-10 | 杭州昭朗五金有限公司 | Formaldehyde-free glued jointed board and production process thereof |
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