Adhesive composition for artificial board and application thereof

Abstract

The invention relates to the technical field of adhesives, and discloses an adhesive composition for artificial boards and application thereof.The adhesive composition comprises a component A and a component B. The component A is multi-element modified isocyanate, and a preparation method of the multi-element modified isocyanate comprises the steps that TDI, MDI and polymerized MDI are added into a reaction kettle, the temperature is increased to 40 DEG C, amino polyether is dropwise added, and the temperature is increased to 40 DEG C; after the residual NCO group reaches a theoretical value, raising the temperature to 80 DEG C, then dropwise adding polyfunctional polyether, and after the residual NCO group reaches the theoretical value, obtaining the component A; the component B is prepared by mixing the following raw materials in percentage by weight: 3-10% of polyether capable of reacting with isocyanate, 2-5% of amino polyether, 50-70% of polyamine, 3-10% of modified polyamine and 5-30% of water; the adhesive composition provided by the invention does not contain formaldehyde, and does not generate formaldehyde in the production, processing and use processes; rapid curing can be achieved, and on the premise of rapid curing, the strength of the manufactured artificial board is larger than or equal to 0.8 MPa.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, and in particular to an adhesive composition for artificial boards and application thereof. Background Art

[0002] In the relevant technology, the "triamine glue" used in the production of artificial boards (plywood, fiberboard, particleboard, etc.) is mostly urea-formaldehyde resin, phenol-formaldehyde resin and melamine-formaldehyde resin. With the upgrading of the wood processing industry and the increasing demand of the consumer market for formaldehyde-free and environmentally friendly home decoration materials, the artificial board industry has gradually turned to the use of environmentally friendly adhesives that do not contain formaldehyde. In addition, due to the current fierce industry competition, many artificial board companies have put forward higher requirements for the production efficiency of formaldehyde-free adhesives: it is necessary to increase the curing rate of formaldehyde-free adhesives, reduce the time of cold pressing and hot pressing, and ensure the strength of the processed artificial boards. Summary of the invention

[0003] The purpose of the present invention is to solve the related technical problems mentioned in the background technology at least to a certain extent. To this end, the present invention provides an adhesive composition for artificial boards and its application.

[0004] In order to achieve the above-mentioned object, the first aspect of the present invention provides an adhesive composition for artificial boards, comprising component A and component B, wherein component A is a polyvalent modified isocyanate, and the preparation method of the polyvalent modified isocyanate comprises adding TDI, MDI and polymerized MDI into a reaction kettle, heating to 40° C., dripping amino polyether, and after the residual NCO group reaches a theoretical value, heating to 80° C., and then dripping a multifunctional polyether, and after the residual NCO group reaches a theoretical value, the component A is obtained;

[0005] The B component is a mixture of raw materials with the following percentages: 3-10% of polyether capable of reacting with isocyanate, 2-5% of amino polyether, 50-70% of polyamine, 3-10% of modified polyamine and 5-30% of water.

[0006] Preferably, the polyvalent modified isocyanate is prepared from the following raw materials in parts by weight: 15 parts of TDI, 5 parts of MDI, 80 parts of polymeric MDI, 2 parts of amino polyether and 5 parts of multifunctional polyether.

[0007] Preferably, in the raw materials for preparing the component A, the MDI is MDI-50, and the NCO content of the polymeric MDI is 20-35%, preferably 30%.

[0008] Preferably, in the raw materials for preparing the component A, the structure of the amino polyether is HO-R-NH2, wherein R is –(CH2----CH2) n–, wherein 3≤n≤50, preferably, 3≤n≤25.

[0009] Preferably, in the raw materials for preparing the component A, the functionality of the multifunctional polyether is 3 or 4, and the multifunctional polyether is one or two of trimethylolpropane, tetramethylolmethane, PPG, and PTMG.

[0010] Preferably, in the component B, the polyether is one or two of PEG200, PEG400, PEG600 and diethylene glycol.

[0011] Preferably, in the component B, the amino polyether is a compound having a molecular weight of less than 400 and containing one hydroxyl group and one amino group.

[0012] Preferably, in the component B, the polyamine is at least three of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, monoethanolamine, diethanolamine and triethanolamine.

[0013] Preferably, in the component B, the modified polyamine is a cardanol-modified polyamine or a glycidyl ether-modified polyamine.

[0014] The second aspect of the present invention provides an application of the above-mentioned adhesive composition for artificial boards, which includes mixing component A and component B evenly to form an adhesive composition, then spraying the adhesive composition onto wood chips, and forming the adhesive composition by high-temperature pressing to obtain the artificial board; wherein the weight ratio of the component A, the component B and the wood chips is (20-10):1:650.

[0015] Through the above technical scheme, the adhesive composition provided by the present invention does not contain formaldehyde, and no formaldehyde will be generated during the production, processing and use processes. The adhesive composition can achieve rapid curing, and specifically can achieve complete curing within 60 seconds under the temperature condition of 200°C; in addition, under the premise of rapid curing, the strength of the artificial board processed based on the adhesive composition provided by the present invention is ≥0.80MPa; therefore, the adhesive composition provided by the present invention has broad application prospects in the field of artificial board production. DETAILED DESCRIPTION

[0016] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0017] The first aspect of the present invention provides an adhesive composition for artificial boards, comprising a component A and a component B, wherein the component A is a polyvalent modified isocyanate, and the preparation method of the polyvalent modified isocyanate comprises adding TDI, MDI and polymerized MDI into a reaction kettle, heating the reaction kettle to 40° C., dripping an amino polyether, and after the residual NCO group reaches a theoretical value, heating the reaction kettle to 80° C., dripping a multifunctional polyether, and after the residual NCO group reaches a theoretical value, obtaining the component A;

[0018] The B component is a mixture of raw materials with the following percentages: 3-10% of polyether capable of reacting with isocyanate, 2-5% of amino polyether, 50-70% of polyamine, 3-10% of modified polyamine and 5-30% of water.

[0019] The adhesive composition provided by the present invention comprising the above-mentioned component A and component B does not contain formaldehyde, and no formaldehyde is generated during the production, processing and use processes. The adhesive composition can achieve rapid curing, specifically, can achieve complete curing within 60 seconds under the temperature condition of 200° C.; in addition, under the premise of rapid curing, the strength of the artificial board processed based on the adhesive composition provided by the present invention is greater than 0.6 MPa; therefore, the adhesive composition provided by the present invention has broad application prospects in the field of artificial board production.

[0020] In the present invention, the polyvalent modified isocyanate is prepared from the following raw materials in parts by weight: 15 parts of TDI, 5 parts of MDI, 80 parts of polymeric MDI, 2 parts of amino polyether and 5 parts of multifunctional polyether.

[0021] In the present invention, in the raw materials for preparing the component A, the MDI is MDI-50, and the NCO content of the polymerized MDI is 20-35%, preferably 30%.

[0022] In the present invention, in the raw materials for preparing the component A, the structure of the amino polyether is HO-R-NH2, wherein R is –(CH2----CH2) n –, 3≤n≤50, preferably, 3≤n≤25. The inventors of the present application have found in practice that if n is too large, the molecular weight will be large, resulting in too high viscosity of component A, which is not conducive to uniform spraying of the adhesive composition of the present invention in the wood chips, so n≤25 is preferred.

[0023] In the present invention, in the raw materials for preparing the component A, the functionality of the multifunctional polyether is 3 or 4, and the multifunctional polyether is one or two of trimethylolpropane, tetramethylolmethane, PPG, and PTMG.

[0024] In the present invention, in the component B, the polyether is one or two of PEG200, PEG400, PEG600 and diethylene glycol.

[0025] In the present invention, in the component B, the amino polyether is a compound having a molecular weight of less than 400 and containing one hydroxyl group and one amino group. Thus, the viscosity of the final adhesive composition is appropriate.

[0026] In the present invention, in the B component, the polyamine is at least three of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, monoethanolamine, diethanolamine, and triethanolamine; it should be noted that by selecting at least three polyamines for mixing, both the reaction speed and the network cross-linking are guaranteed.

[0027] In the present invention, in the component B, the modified polyamine is a cardanol-modified polyamine or a glycidyl ether-modified polyamine.

[0028] The second aspect of the present invention provides an application of the above-mentioned adhesive composition for artificial boards, which includes mixing component A and component B evenly to form an adhesive composition, then spraying the adhesive composition onto wood chips, and forming the adhesive composition by high-temperature pressing to obtain the artificial board; wherein the weight ratio of the component A, the component B and the wood chips is (20-10):1:650.

[0029] The adhesive composition provided by the present invention is specifically described below through specific examples.

[0030] Example 1

[0031] In the adhesive composition provided in this embodiment, the raw materials used to prepare component A and the raw material formula contained in component B are shown in the following table.

[0032]

[0033] The preparation method of component A includes: adding 15g TDI, 5g MDI-50 and 80g polymerized MDI (NCO content is 30%) into a reactor, heating to 40°C, and dropping 2g amino polyether (HO–(CH2----CH2) 10 –NH2), and ensure that the dripping is completed within 3 hours. After the residual NCO group reaches the theoretical value, the temperature is raised to 80°C, and 5g of polyether PPG (functionality 3) is dripped, and ensure that the dripping is completed within 3 hours. After the residual NCO group reaches the theoretical value, the A component is obtained;

[0034] In this embodiment, component A and component B are mixed evenly to form an adhesive composition, and then the adhesive composition is sprayed onto wood chips and formed by high-temperature pressing to obtain an artificial board; wherein the weight ratio of the component A, the component B and the wood chips is 18:1:650.

[0035] Example 2

[0036] In the adhesive composition provided in this embodiment, the raw materials used to prepare component A and the raw material formula contained in component B are shown in the following table.

[0037]

[0038] The preparation method of component A includes: adding 15g TDI, 5g MDI-50 and 80g polymerized MDI (NCO content is 30%) into a reactor, heating to 40°C, and dropping 2g amino polyether (HO–(CH2----CH2) 15 –NH2), and ensure that the dripping is completed within 3 hours. After the residual NCO group reaches the theoretical value, the temperature is raised to 80°C, and 5g of polyether PPG (functionality 3) is dripped, and ensure that the dripping is completed within 3 hours. After the residual NCO group reaches the theoretical value, the A component is obtained;

[0039] In this embodiment, component A and component B are mixed evenly to form an adhesive composition, and then the adhesive composition is sprayed onto wood chips and formed by high-temperature pressing to obtain an artificial board; wherein the weight ratio of the component A, the component B and the wood chips is 19:1:650.

[0040] Example 3

[0041] In the adhesive composition provided in this embodiment, the raw materials used to prepare component A and the raw material formula contained in component B are shown in the following table.

[0042]

[0043]

[0044] The preparation method of component A includes: adding 15g TDI, 5g MDI-50 and 80g polymerized MDI (NCO content is 30%) into a reaction kettle, heating to 40°C, dripping 2g amino polyether (HO-(CH2----CH2)3-NH2), and ensuring that the dripping is completed within 3 hours, and after the residual NCO group reaches the theoretical value, heating to 80°C, and then dripping 5g polyether PTMG (functionality 4), and ensuring that the dripping is completed within 3 hours, and after the residual NCO group reaches the theoretical value, the component A is obtained;

[0045] In this embodiment, component A and component B are mixed evenly to form an adhesive composition, and then the adhesive composition is sprayed onto wood chips and formed by high-temperature pressing to obtain an artificial board; wherein the weight ratio of the component A, the component B and the wood chips is 20:1:650.

[0046] Comparative Example 1

[0047] The crude MDI is uniformly sprayed into the wood chips, and the wood-based panels are formed by high-temperature pressing, wherein the weight ratio of the crude MDI to the wood chips is 45:650.

[0048] The curing time of the artificial boards prepared in Examples 1-3 was counted, and the strength of the artificial boards was tested according to the test method in GBT 17657-2013. The test results are summarized in Table 1.

[0049] Table 1:

[0050] Curing time Strength MPa Yield % Example 1 55 0.80 99.6 Example 2 50 0.85 99.9 Example 3 43 0.90 99.4 Comparative Example 1 120 0.38 95.1

[0051] It can be seen from the data of the above embodiments that the adhesive composition provided by the present invention can not only be cured in a shorter time, but also the strength of the obtained artificial board after curing has obvious advantages (≥0.80MPa), and the yield rate of artificial boards produced by the adhesive composition provided by the present invention is significantly improved. Therefore, the adhesive composition provided by the present invention has broad application prospects.

[0052] The above shows and describes the basic principles, main features and characteristics of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of the present invention to be protected is defined by the attached claims and their equivalents.

Claims

1. An adhesive composition for artificial boards, characterized in that: The invention comprises a component A and a component B, wherein the component A is a polyvalent modified isocyanate, and the preparation method of the polyvalent modified isocyanate comprises the following steps: adding TDI, MDI and polymerized MDI into a reaction kettle, heating the temperature to 40° C., dripping an amino polyether, and after the residual NCO group reaches a theoretical value, heating the temperature to 80° C., dripping a multifunctional polyether, and after the residual NCO group reaches a theoretical value, obtaining the component A; The B component is a mixture of raw materials with the following percentages: 3-10% of polyether capable of reacting with isocyanate, 2-5% of amino polyether, 50-70% of polyamine, 3-10% of modified polyamine and 5-30% of water.

2. The adhesive composition for artificial boards according to claim 1, characterized in that: The polyvalent modified isocyanate is prepared from the following raw materials in parts by weight: 15 parts of TDI, 5 parts of MDI, 80 parts of polymeric MDI, 2 parts of amino polyether and 5 parts of multifunctional polyether.

3. The adhesive composition for artificial boards according to claim 1, characterized in that: In the raw materials for preparing the component A, the MDI is MDI-50, and the NCO content of the polymerized MDI is 20-35%, preferably 30%.

4. The adhesive composition for artificial boards according to claim 1, characterized in that: In the preparation raw materials of the A component, the structure of the amino polyether is HO-R-NH2, wherein R is –(CH2----CH2) n –, wherein 3≤n≤50, preferably, 3≤n≤25.

5. The adhesive composition for artificial boards according to claim 1, characterized in that: In the raw materials for preparing the component A, the functionality of the multifunctional polyether is 3 or 4, and the multifunctional polyether is one or two of trimethylolpropane, tetramethylolmethane, PPG, and PTMG.

6. The adhesive composition for artificial boards according to claim 1, characterized in that: In the B component, the polyether is one or two of PEG200, PEG400, PEG600 and diethylene glycol.

7. The adhesive composition for artificial boards according to claim 1, characterized in that: In the B component, the amino polyether is a compound having a molecular weight of less than 400 and containing one hydroxyl group and one amino group.

8. The adhesive composition for artificial boards according to claim 1, characterized in that: In the component B, the polyamine is at least three of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, monoethanolamine, diethanolamine and triethanolamine.

9. The adhesive composition for artificial boards according to claim 1, characterized in that: In the component B, the modified polyamine is cardanol-modified polyamine or glycidyl ether-modified polyamine.

10. An application of the adhesive composition for artificial boards according to any one of claims 1 to 9, characterized in that: The application includes uniformly mixing component A and component B to form an adhesive composition, then spraying the adhesive composition onto wood chips, and forming the wood-based panels by high-temperature pressing; wherein the weight ratio of component A, component B and wood chips is (20-10):1:650.

Images