Bio-based adhesive and preparation method thereof

Abstract

The invention discloses a bio-based adhesive and a preparation method thereof, the preparation method comprises a preparation process of a bio-based polyurethane prepolymer, and the preparation process comprises the following steps: introducing dried bio-based polyol with a hydroxyl value of greater than 170mgKOH / g and bio-based polyisocyanate into a column type reaction runner with a length-diameter ratio of greater than 100, reacting in the flowing process to generate a bio-based polyurethane prepolymer; wherein the column type reaction flow channel comprises a flow channel body with a flow channel cavity and a plurality of catalytic compounds filled in the flow channel cavity, and each catalytic compound comprises a porous material and a catalyst which is loaded on the porous material and is used for catalyzing reaction; the catalytic compound is movably arranged relative to the flow channel chamber and is limited in the flow channel chamber; the bio-based adhesive prepared by the method has excellent inter-batch quality stability and can be stored for a long time.

Description

Technical Field

[0001] The present invention relates to the field of adhesives, in particular to bio-based adhesives, and specifically to a bio-based adhesive and a preparation method thereof. Background Art

[0002] Adhesive is a substance with excellent bonding properties, which plays the role of connecting objects by bonding the surface through adhesion and cohesion. There are many varieties of adhesives with different components. Among them, polyurethane adhesives, as an important variety of synthetic adhesives, have always attracted much attention for their preparation. Usually, polyurethane adhesives include polyurethane prepolymers, which are prepared by reacting polyols and isocyanates in a reactor, and then mixed with other raw materials such as fillers to form adhesives. However, it has been found in practice that the polyurethane adhesives prepared according to the above method have large quality differences between batches when used. In addition, with the continuous improvement of environmental protection requirements, bio-based polyurethane adhesive products are currently emerging. However, the materials used, especially polyols and isocyanates, are not all bio-based materials. Only some bio-based raw materials are available, and the sources are limited and difficult to obtain.

[0003] It should be noted that the information disclosed in the above background technology section is only used to understand the background of the present application, so the background technology section of the present invention may contain background information about the problem or environment of the present invention, but not necessarily describe the prior art. Therefore, the content contained in the background technology section is not an admission of the applicant to the prior art. Summary of the invention

[0004] The object of the present invention is to overcome one or more deficiencies in the prior art and to provide an improved method for preparing a bio-based adhesive and a bio-based adhesive prepared therefrom. The bio-based adhesive prepared by the method has excellent batch-to-batch quality stability and can be stored for a long time.

[0005] In order to achieve the above object, a technical solution adopted by the present invention is:

[0006] A method for preparing a bio-based adhesive, the method comprising a preparation process of a bio-based polyurethane prepolymer, the preparation process of the bio-based polyurethane prepolymer comprising: introducing a dried bio-based polyol having a hydroxyl value greater than 170 mgKOH / g and a bio-based polyisocyanate into a columnar reaction flow channel having an aspect ratio greater than 100, and reacting to generate a bio-based polyurethane prepolymer during the flow process;

[0007] Among them, the columnar reaction channel includes a channel body forming a channel chamber, and a plurality of catalytic complexes filled in the channel chamber, the catalytic complexes include a porous material and a catalyst loaded on the porous material and used to catalyze the reaction; the catalytic complexes are movably arranged relative to the channel chamber and are confined in the channel chamber.

[0008] According to some preferred aspects of the present invention, the radial dimension of the flow channel chamber varies in its own length direction.

[0009] In some embodiments of the present invention, the changes have a periodic pattern.

[0010] According to some preferred aspects of the present invention, the maximum radial dimension of the flow channel chamber is H1 and the minimum is H2, the radial dimension of the catalytic complex is R, and the following conditions are satisfied: H2<n×R

[0011] According to some preferred aspects of the present invention, a plurality of arc-shaped protrusions are formed on the inner wall of the flow channel chamber.

[0012] According to some preferred aspects of the present invention, the plurality of arc-shaped protrusions are respectively formed on the upper side and the lower side of the inner wall of the flow channel chamber and are symmetrically arranged in pairs.

[0013] According to some preferred aspects of the present invention, on each side, the distance between any two adjacent arc-shaped protrusions gradually increases from outside to inside in the radial direction, and a part of the distance is smaller than the radial dimension of the catalytic complex.

[0014] In some embodiments of the present invention, the multiple arc-shaped protrusions divide the flow channel chamber into a first chamber and a second chamber connected to the first chamber, the first chamber and the second chamber each have at least one, and the volume of the second chamber is greater than the volume of the first chamber.

[0015] In some embodiments of the present invention, filter screens are respectively provided at the inlet and the outlet of the flow channel chamber to prevent the catalytic complex from leaving the flow channel chamber.

[0016] According to some preferred aspects of the present invention, the porous material has a diameter of 0.4-4.5 mm and a pore size of 0.05-400 μm.

[0017] In some embodiments of the present invention, the porous material is made of silicon dioxide.

[0018] According to some preferred aspects of the present invention, the temperature in the column reaction channel is controlled to be 70-100° C., and the reaction residence time is 10-30 min. ​

[0019] According to some preferred aspects of the present invention, the aspect ratio of the columnar reaction channel is 100-8000.

[0020] According to some preferred aspects of the present invention, the total loading amount of the catalyst is 0.05%-1.0%, further 0.2%-0.5%, of the total mass of the bio-based polyol and the bio-based polyisocyanate in the flow channel chamber.

[0021] In some embodiments of the present invention, the catalytic composite is formed by loading the catalyst on the porous material by impregnation. Further, the catalyst is a combination of one or more selected from organic bismuth catalysts, organic zinc catalysts, and organic tin catalysts.

[0022] According to some preferred aspects of the present invention, the bio-based polyol has a hydroxyl value of 170-400 mgKOH / g, a molecular weight of 100-2000 g / mol, and a viscosity of no more than 5000 mPa·s.

[0023] Further, in some embodiments of the present invention, the bio-based polyol is a combination of one or more selected from modified soybean oil with hydroxyl groups, BioPTMG polytetramethyl ether glycol, PO3G polytrimethylene ether glycol, HM-635S sorbitol polyether polyol, modified castor oil polyol, and palm oil polyol. These bio-based polyols have good biodegradability and renewability, which helps to reduce the environmental burden of materials.

[0024] In some embodiments of the present invention, the bio-based adhesive is a one-component bio-based adhesive, and the embodiments of preparing the one-component bio-based adhesive include:

[0025] The bio-based polyol is pumped into a drying channel filled with a desiccant, and the dried bio-based polyol, bio-based polyisocyanate and a selective chain extender are respectively pumped into the columnar reaction channel to generate a bio-based polyurethane prepolymer, and then the bio-based polyurethane prepolymer is mixed with other raw materials to obtain the single-component bio-based adhesive.

[0026] In some embodiments of the present invention, the one-component bio-based adhesive comprises, by weight:

[0027] Bio-based polyol 32-50 parts

[0028] 38-50 parts of bio-based polyisocyanate

[0029] Chain extender 2-6 parts

[0030] 1-25 parts of auxiliary agent;

[0031] The auxiliary agent is a combination of one or more selected from anti-sagging agent, pigment, dispersant, antifungal agent, defoaming agent and flame retardant.

[0032] In some embodiments of the present invention, the pigment is a combination of one or more selected from shell powder, calcium powder, glass beads, bio-based pigment BioBlack TX, and Valley Blue VBL007, which gives the material good color and hiding power.

[0033] In some embodiments of the present invention, the anti-sagging agent is a combination of one or more selected from fumed silica, nano calcium carbonate, modified bentonite, hydrogenated castor oil, and polyamide wax to improve the construction performance and leveling of the material. Preferably, nano calcium carbonate and hydrogenated castor oil are used.

[0034] In some embodiments of the present invention, the antifungal agent is selected from one or a combination of nano zinc oxide and nano silver, which can endow the material with good antifungal properties.

[0035] In some embodiments of the present invention, the defoaming agent is a combination of one or more selected from acrylates, polysiloxane solutions, modified polysiloxane solutions, and polysiloxane containing hydrophobic particles.

[0036] In some embodiments of the present invention, the chain extender is one or a combination of 1,4-butanediol, 1,3-propylene glycol, 1,6-hexanediol, and polyaspartic acid ester prepared by Michael addition reaction of dialkyl maleate and aliphatic primary diamine.

[0037] In some embodiments of the present invention, the flame retardant is one or a combination of several selected from aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, antimony trioxide, zinc borate, barium metaborate, and antimony oxide-silicon oxide composite.

[0038] In some embodiments of the present invention, the catalyst is a combination of one or more selected from an organic bismuth catalyst, an organic zinc catalyst, and an organic tin catalyst.

[0039] According to some preferred aspects of the present invention, the bio-based polyisocyanate is prepared by the following method:

[0040] React 1,1-dimethyl-2,2,2-trichloroethoxycarbonyl chloride with sodium azide to generate a compound represented by formula (I);

[0041]

[0042] Further, the reaction is carried out at 20-40° C. in an organic solvent; further, the organic solvent may be acetone or the like;

[0043] The compound represented by formula (I) is reacted with azelaic acid to generate a bio-based polyisocyanate represented by formula (II);

[0044]

[0045] Furthermore, the reaction is carried out at 60-80° C. in the presence of 4-dimethylaminopyridine in an organic solvent; further, the organic solvent may be acetonitrile or the like.

[0046] Furthermore, the azelaic acid can be prepared by ozonolysis of biomass acid. The method of preparing azelaic acid by ozonolysis of biomass acid can be carried out with reference to the prior art, or azelaic acid from bio-based sources can be directly purchased.

[0047] Furthermore, the biomass acid may be oleic acid.

[0048] The method for preparing bio-based polyisocyanate of the present invention is simple to operate and has a high yield. Azelaic acid has a wide source and can be prepared by ozone decomposition of biomass acid, thus overcoming the defect that existing biomass polyisocyanate is not easy to obtain.

[0049] Another technical solution provided by the present invention is a method for preparing a polyurethane adhesive, the method comprising a preparation process of a polyurethane prepolymer, the preparation process of the polyurethane prepolymer comprising: introducing a dried polyol having a hydroxyl value greater than 170 mgKOH / g and a polyisocyanate into a columnar reaction flow channel having a length-to-diameter ratio greater than 100, and reacting to generate a polyurethane prepolymer during the flow process; wherein the columnar reaction flow channel comprises a flow channel body forming a flow channel chamber, and a plurality of catalytic composites filled in the flow channel chamber, the catalytic composites comprising a porous material and a catalyst loaded on the porous material and used to catalyze the reaction; the catalytic composites are movably arranged relative to the flow channel chamber and confined in the flow channel chamber.

[0050] Another technical solution provided by the present invention is a bio-based adhesive, which is prepared by the above-mentioned method for preparing the bio-based adhesive.

[0051] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0052] The present invention is based on the problem that the polyurethane adhesive prepared in the prior art has large quality differences between batches when used. After a large number of experimental studies, the inventors of the present invention believe that this is caused by the existing use of a reactor to react polyols and isocyanates. First, after the added catalyst is added to the reactor, the dispersion efficiency may be low by stirring, resulting in a more intense local reaction, while the reaction of the part without the catalyst is slower. The dispersion conditions may be different for each reaction, resulting in different structures and molecular weights of each batch of polyurethane prepolymers, and obvious quality differences. Second, the added catalyst remains in the polyurethane prepolymer, making it difficult to separate it. Therefore, the catalyst usually remains in the product, causing the catalyst to work during storage, causing the isocyanate group to further react with the carbamate, changing the structure and molecular weight of the polyurethane prepolymer, thereby causing significant differences in the structure and molecular weight of the polyurethane prepolymer between batches, resulting in unstable quality of the adhesive; thirdly, the reaction between the isocyanate group and the hydroxyl group is an exothermic process, and it is difficult for the existing conventional reactor to timely conduct the heat released by the internal reaction through the reactor wall, resulting in heat concentration, which in turn causes different reaction degrees in different areas, resulting in large differences in the quality and viscosity of the polyurethane prepolymer obtained in each batch;

[0053] Based on the above findings, the present invention innovatively proposes a new type of columnar reaction channel for the reaction of polyisocyanate and polyol, and by controlling the aspect ratio, the reaction raw materials can react to generate polyurethane prepolymers during the process, especially the catalyst required for the reaction is loaded on the porous material in a loaded manner, and the catalytic composite formed after the catalyst is loaded is movably arranged in the columnar reaction channel, that is, the catalytic composite can move freely at a local position in the channel chamber, and then in the process of contact with the reaction raw materials, the two can not only maximize the contact, the contact area is large, but also the reaction materials can be brought into contact with each other by the flow impact during the process. The catalytic complex moves freely and rotates, which increases the disturbance of the fluid, further improves the mixing uniformity of the polyisocyanate and the polyol, improves the catalyst effect, and improves the reaction balance; at the same time, since the columnar reaction flow channel with a relatively large aspect ratio can provide more contact area with the flowing reaction mixture, the heat will not be concentrated and can be dispersed more easily, thereby avoiding the problem of unbalanced reaction caused by heat concentration; in addition, after the catalyst of the present invention is loaded and fixed, it will not flow out with the outflow of the polyurethane prepolymer, and it is not only reusable, but also avoids a series of problems caused by the catalyst remaining in the polyurethane prepolymer.

[0054] Therefore, the present invention solves the problem that the polyurethane adhesive prepared in the prior art has large quality differences between batches when used. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a schematic structural diagram of a flow channel body of a column-type reaction flow channel in an embodiment of the present invention;

[0056] Figure 2 One of the structural schematic diagrams of the column-type reaction channel (the catalytic composite is filled in a single row) used in the embodiments of the present invention;

[0057] Figure 3 The second structural schematic diagram of the column-type reaction channel (the catalytic composite is filled in double rows) used in the embodiment of the present invention;

[0058] Figure 4 The third structural schematic diagram of the columnar reaction channel (the catalytic composite is filled in three rows) used in the embodiment of the present invention;

[0059] Figure 5 It is a schematic diagram of the structure of the production device used in the preparation process of the single-component bio-based adhesive in an embodiment of the present invention;

[0060] In the accompanying drawings: 100, columnar reaction channel; 110, channel body; 111, channel chamber; 1111, first chamber; 1112, second chamber; 112, arc-shaped protrusion; 120, catalytic complex; 200, bio-based polyol storage tank; 300, bio-based polyisocyanate storage tank; 400, drying channel; 510, chain extender storage tank; 520, additive storage bin; 600, twin-screw extruder; 700, product storage tank. DETAILED DESCRIPTION

[0061] The present invention provides a method for preparing a bio-based adhesive with relatively stable quality between batches, so as to reduce and / or eliminate the negative impact caused by problems in operation and reaction equipment during the preparation process.

[0062] The improved bio-based adhesive method includes a preparation process of a bio-based polyurethane prepolymer, which includes: introducing a dried bio-based polyol with a hydroxyl value greater than 170 mgKOH / g and a bio-based polyisocyanate into a columnar reaction channel with an aspect ratio greater than 100, and reacting to generate a bio-based polyurethane prepolymer during the flow process; wherein the columnar reaction channel includes a channel body formed with a channel cavity, and a plurality of catalytic composites filled in the channel cavity, wherein the catalytic composites include a porous material and a catalyst loaded on the porous material and used to catalyze the reaction; and the catalytic composites are movably arranged relative to the channel cavity and confined in the channel cavity.

[0063] Combine the following Figures 1 to 5 The above preparation method of the present invention is further described. Figures 1 to 4The structural schematic diagram of the column-type reaction channel used in the present invention is given as an example. Figure 5 Schematic diagram of the structure of the production device used in the preparation process of one-component bio-based adhesive.

[0064] The columnar reaction channel 100 includes a channel body 110 formed with a channel chamber 111, and a plurality of catalytic complexes 120 filled in the channel chamber 111. The catalytic complexes 120 include a porous material and a catalyst loaded on the porous material and used for catalytic reaction; the catalytic complexes 120 are movably arranged relative to the channel chamber 111 and are confined in the channel chamber 111.

[0065] The radial dimension of the flow channel chamber 111 varies in its own length direction, and the variation has a periodic law, such as Figure 1 As shown, the radial dimension of the flow channel chamber 111 in its own length direction first decreases and then increases, decreases and then increases, and repeats this cycle. This change can change the local flow rate of the reaction material passing through, and the different flow rates at various positions will aggravate the fluidity differences of the reaction materials, thereby producing a mutual disturbance effect, which can increase the mixing uniformity between the reaction materials such as bio-based polyols and bio-based polyisocyanates, improve the reaction efficiency and reaction balance, and can quickly disperse and transfer heat outward through the chamber wall during the disturbance and mutual circulation process, avoiding the concentration of heat in local positions.

[0066] Furthermore, the maximum radial dimension of the flow channel chamber 111 is H1 and the minimum radial dimension is H2, the radial dimension of the catalytic complex 120 is R, and the following conditions are satisfied: H2<n×R Figure 1 and 2 As shown, such a configuration can prevent the catalytic compound 120 from circulating in a large range and be limited to a specific spatial position. On the one hand, it can prevent the catalytic compound 120 from being aggregated together; on the other hand, it is conducive to evenly distributing the filled catalytic compound 120 along the length direction of the flow channel chamber 111, thereby improving the catalytic uniformity and stability.

[0067] In practice, the value of n is determined according to the configuration of the catalytic complex 120, for example, Figure 2 As shown, the catalytic composite 120 is filled in a single row, in which case n is 1; if Figure 3 As shown, the catalytic composite 120 is filled in double rows, and n is 2; if Figure 4 As shown, the catalytic composites 120 are filled in three rows, and in this case n is 3, and so on; such an arrangement is more conducive to uniform dispersion of the catalyst.

[0068] ​Furthermore, a plurality of arc-shaped protrusions 112 are formed on the inner wall of the flow channel chamber 111, and the plurality of arc-shaped protrusions 112 are respectively formed on the upper side and the lower side of the inner wall of the flow channel chamber 111 and are symmetrically arranged in pairs; on each side, the distance between any two adjacent arc-shaped protrusions 112 gradually increases from the outside to the inside along the radial direction, and some of the distances are smaller than the radial dimension of the catalytic complex 120. Figure 1 As shown, the aforementioned multiple arc-shaped protrusions 112 separate the flow channel chamber 111 into a first chamber 1111 and a second chamber 1112 connected to the first chamber 1111. The first chamber 1111 and the second chamber 1112 each have at least one, and the volume of the second chamber 1112 is greater than the volume of the first chamber 1111. The arrangement of the aforementioned arc-shaped protrusions 112 realizes that the radial dimension of the flow channel chamber 111 changes in its own length direction, and the arc-shaped protrusions 112 can further increase the contact area and improve the heat dissipation efficiency on the one hand, and on the other hand, can change the direction of fluid flow and increase the turbulence effect, that is, can further improve the uniformity of dispersion and mixing; in addition, the arrangement of the aforementioned arc-shaped protrusions 112 can also increase the probability of the catalytic complex being driven to move or rotate in the reaction material, thereby effectively ensuring the uniformity of dispersion of the catalytic complex 120, improving the catalyst effect, and improving the reaction balance.

[0069] Furthermore, in order to prevent the catalytic complex 120 from being carried out of the flow channel chamber 111 under certain special circumstances, filter screens can be respectively set at the inlet and outlet of the flow channel chamber 111 to prevent the catalytic complex from leaving the flow channel chamber. The aspect ratio of the columnar reaction channel 100 can be 100-8000.

[0070] Furthermore, the diameter of the porous material is 0.4-4.5 mm, the pore size is 0.05-400 μm, the material of the porous material is silicon dioxide, and the total loading amount of the catalyst is 0.05%-1.0% of the total mass of the bio-based polyol and the bio-based polyisocyanate in the flow channel chamber, for example, it can be 0.2%-0.5%; the catalytic composite is formed by loading the catalyst on the porous material by impregnation, and the catalyst is a combination of one or more selected from organic bismuth catalysts, organic zinc catalysts, and organic tin catalysts.

[0071] Specifically, the preparation method of the catalytic composite is as follows: drying the porous material in a forced air drying oven, taking it out and placing it in a drying tower to cool it to room temperature, preparing ethanol and ethyl acetate into a mixed solution, adding a measured amount of catalyst and the dried porous material, stirring it fully, filtering it, and then placing it in a forced air drying oven to dry it to obtain the catalytic composite.

[0072] Furthermore, the temperature in the column reaction channel 100 is controlled to be 70-100° C., and the reaction residence time is 10-30 min. In the present invention, a temperature control device such as some heat exchangers can be used to control the temperature in the column reaction channel.

[0073] Furthermore, the bio-based adhesive is a single-component bio-based adhesive. The implementation method of preparing the single-component bio-based adhesive includes: pumping the bio-based polyol into a drying channel 400 filled with a desiccant, and pumping the dried bio-based polyol, bio-based polyisocyanate and a selective chain extender into the columnar reaction channel 100 respectively to generate a bio-based polyurethane prepolymer, and then mixing the bio-based polyurethane prepolymer with other raw materials to obtain a single-component bio-based adhesive.

[0074] See also Figure 5 As shown, the production device used in the preparation process of the single-component bio-based adhesive includes a column reaction channel 100, a bio-based polyol storage tank 200, a bio-based polyisocyanate storage tank 300, a drying channel 400, a chain extender storage tank 510, an auxiliary agent storage bin 520, a twin-screw extruder 600 and a product storage tank 700; the bio-based polyol storage tank 200, the drying channel 400, the column reaction channel 100, the twin-screw extruder 600 and the product storage tank 700 are connected in sequence, and the bio-based polyisocyanate storage tank 510 is connected to the bio-based polyol storage tank 200. The cyanate storage tank 300 is connected to the column reaction channel 100, the chain extender storage tank 510 is connected to the column reaction channel 100, the chain extender storage tank 510 can be connected to the bio-based polyisocyanate storage tank 300 through a pipeline or different pipelines and the column reaction channel 100, the auxiliary agent storage bin 520 is connected to the twin-screw extruder 600, the auxiliary agent storage bin 520 can buffer the auxiliary agent, and there can be one or more, for example, the auxiliary agent can be stored in multiple storage bins or mixed and stored together.

[0075] Furthermore, the twin-screw extruder 600 is used to mix the materials uniformly, and its operating parameters are: rotation speed of 300-700 rpm, and residence time of 3-10 min.

[0076] Furthermore, the single-component bio-based adhesive includes, by weight: 32-50 parts of bio-based polyol, 38-50 parts of bio-based polyisocyanate, 2-6 parts of chain extender, and 1-25 parts of auxiliary agent, wherein the auxiliary agent is a combination of one or more selected from anti-sagging agent, pigment, dispersant, antifungal agent, defoaming agent, and flame retardant.

[0077] Furthermore, the drying channel 400 is mainly used to control the water content of the bio-based polyol. For example, the water content is preferably controlled below 500 ppm. A circulation pipe can be provided, and a fixed desiccant is filled in the circulation pipe so that the bio-based polyol is dehydrated by the desiccant during the circulation process. Of course, other methods can also be used to remove the water contained in the bio-based polyol, which will not be described in detail here.

[0078] Furthermore, before the preparation begins, each device may be prepared for dehydration, for example, by heating and drying. For channels, inert gases such as nitrogen may be introduced in advance to replace the water-containing air inside.

[0079] The above scheme is further described below in conjunction with specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments; the implementation conditions adopted in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0080] Unless otherwise specified in the following examples, all raw materials are commercially available or prepared by conventional methods in the art.

[0081] In the following, the bio-based polyisocyanate used is prepared according to the following method: 1,1-dimethyl-2,2,2-trichloroethoxycarbonyl chloride and sodium azide are reacted in a molar ratio of 1:1.2 at room temperature in acetone to generate an intermediate; then the intermediate is reacted with azelaic acid in a molar ratio of 2.4:1 at 70°C in the presence of 4-dimethylaminopyridine in acetonitrile to generate a bio-based polyisocyanate, and the product is separated and purified by thin film distillation separation technology at a separation pressure of 100 Pa and a temperature of 130°C to obtain a purified bio-based polyisocyanate.

[0082] In the following, the catalytic composite is prepared by the following method: the porous material is dried in a 120°C forced air drying oven for 3 hours, taken out and placed in a drying tower to cool to room temperature, ethanol and ethyl acetate are mixed in a 1:1 ratio, a measured amount of catalyst and the dried porous material are added, stirred thoroughly for 1 hour, filtered, and then placed in a 120°C forced air drying oven to dry for 3 hours to obtain the catalytic composite.

[0083] Example 1

[0084] This example provides a method for preparing a one-component bio-based adhesive and the one-component bio-based adhesive prepared by the method. Figure 2 The column reaction channel shown in Figure 5 The device and production process shown;

[0085] Among them, the formula content of the single-component bio-based adhesive is shown in Table 1;

[0086] Table 1

[0087]

[0088] The maximum radial dimension H1 of the flow channel chamber is 4 mm, the minimum radial dimension H2 is 2.5 mm, and the length is 10 m;

[0089] The catalyst is dibutyltin dilaurate, purchased from Jiangsu Mingtai New Materials Co., Ltd., brand T-12; the porous material is silica, the average diameter R of the porous material is 3 mm, purchased from Qingdao Xinchanglai Silica Gel Co., Ltd., brand FNG-C series (customizable size);

[0090] The total loading amount of the catalyst is 0.5% of the total mass of the bio-based polyol and the bio-based polyisocyanate in the flow channel chamber;

[0091] The temperature in the column reaction channel is controlled to be 85° C. and the reaction residence time is 10 min.

[0092] The twin-screw extruder is used to mix the materials evenly, and its operating parameters are: rotation speed is 600 rpm, and residence time is 8 min.

[0093] Example 2

[0094] This example provides a method for preparing a one-component bio-based adhesive and the one-component bio-based adhesive prepared by the method. Figure 3 The column reaction channel shown in Figure 5 The device and production process shown;

[0095] Among them, the formula content of the single-component bio-based adhesive is shown in Table 2;

[0096] Table 2

[0097]

[0098] The maximum radial dimension H1 of the flow channel chamber is 5 mm, the minimum radial dimension H2 is 3.5 mm, and the length is 10 m;

[0099] The catalyst is dibutyltin dilaurate, purchased from Jiangsu Mingtai New Materials Co., Ltd., brand T-12; the porous material is silicon dioxide, the average diameter R of the porous material is 2 mm, purchased from Qingdao Xinchanglai Silica Gel Co., Ltd., brand FNG-C series;

[0100] The total loading amount of the catalyst is 0.4% of the total mass of the bio-based polyol and the bio-based polyisocyanate in the flow channel chamber;

[0101] The temperature in the column reaction channel is controlled to be 70° C. and the reaction residence time is 25 min.

[0102] The twin-screw extruder is used to mix the materials evenly, and its operating parameters are: rotation speed is 600 rpm, and residence time is 8 min.

[0103] Example 3

[0104] This example provides a method for preparing a one-component bio-based adhesive and the one-component bio-based adhesive prepared by the method. Figure 4 The column reaction channel shown in Figure 5 The device and production process shown;

[0105] Among them, the formula content of the single-component bio-based adhesive is shown in Table 3;

[0106] Table 3

[0107]

[0108] The maximum radial dimension of the flow channel chamber is 5 mm in dimension H1, 4 mm in dimension H2, and 10 m in length;

[0109] The catalyst is dibutyltin dilaurate, purchased from Jiangsu Mingtai New Materials Co., Ltd., brand T-12; the porous material is silica, the average diameter R of the porous material is 1.5 mm, purchased from Qingdao Xinchanglai Silica Gel Co., Ltd., brand FNG-C series;

[0110] The total loading amount of the catalyst is 0.3% of the total mass of the bio-based polyol and the bio-based polyisocyanate in the flow channel chamber;

[0111] The temperature in the column reaction channel is controlled to be 100° C. and the reaction residence time is 30 min.

[0112] The twin-screw extruder is used to mix the materials evenly, and its operating parameters are: rotation speed is 600 rpm, and residence time is 8 min.

[0113] Comparative Example 1

[0114] This example provides a bio-based adhesive, which is prepared using a traditional kettle method and has the same formulation as Example 1.

[0115] Preparation process: Add bio-based polyols and chain extenders to a closed reactor, stir and heat, control the temperature at 110±5℃, turn on the vacuum pump to draw negative pressure, control the pressure below -0.08MPa, and evacuate for 1h. Cool down to below 60℃, introduce dry nitrogen to release the vacuum, add bio-based polyisocyanate, control the temperature at 80±2℃, and polymerize for 3h. Cool down to below 50℃, add catalysts and other additives, and stir and mix for 30min.

[0116] Performance Testing

[0117] The bio-based adhesives prepared in the above Examples 1-3 and Comparative Example 1 were subjected to the following performance tests, and the performance test results are shown in Table 4. The viscosity was tested using a NDJ-1s digital rotational viscometer, and the bonding strength was tested in accordance with GB / T 16777-2008.

[0118] Table 4 Bio-based adhesives

[0119]

[0120] It can be seen from Table 4 above that the bio-based adhesive of the present invention has better storage stability.

[0121] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

[0122] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

Claims

1. A method for preparing a bio-based adhesive, characterized in that: The preparation method includes a preparation process of a bio-based polyurethane prepolymer, and the preparation process of the bio-based polyurethane prepolymer includes: introducing a dried bio-based polyol having a hydroxyl value greater than 170 mgKOH / g and a bio-based polyisocyanate into a columnar reaction flow channel with an aspect ratio greater than 100, and reacting to generate a bio-based polyurethane prepolymer during the flow process; Among them, the columnar reaction channel includes a channel body forming a channel chamber, and a plurality of catalytic complexes filled in the channel chamber, the catalytic complexes include a porous material and a catalyst loaded on the porous material and used to catalyze the reaction; the catalytic complexes are movably arranged relative to the channel chamber and are confined in the channel chamber.

2. The method for preparing a bio-based adhesive according to claim 1, characterized in that: The radial dimension of the flow channel chamber varies along its length direction.

3. The method for preparing the bio-based adhesive according to claim 2, characterized in that: The changes have a periodic pattern.

4. The method for preparing a bio-based adhesive according to claim 2, characterized in that: The maximum radial dimension of the flow channel chamber is H1 and the minimum radial dimension is H2. The radial dimension of the catalytic complex is R, and the following condition is satisfied: H2<n×R<H1<(n+1.5)×R, where n is a positive integer.

5. The method for preparing the bio-based adhesive according to claim 2, characterized in that: A plurality of arc-shaped protrusions are formed on the inner wall of the flow channel chamber.

6. The method for preparing the bio-based adhesive according to claim 5, characterized in that: The multiple arc-shaped protrusions are respectively formed on the upper and lower sides of the inner wall of the flow channel chamber and are symmetrically arranged in pairs; and / or, on each side, the distance between any two adjacent arc-shaped protrusions gradually increases from outside to inside along the radial direction, and some distances are smaller than the radial dimension of the catalytic complex.

7. The method for preparing the bio-based adhesive according to claim 5, characterized in that: The multiple arc-shaped protrusions divide the flow channel chamber into a first chamber and a second chamber connected to the first chamber. The first chamber and the second chamber each have at least one, and the volume of the second chamber is greater than the volume of the first chamber.

8. The method for preparing a bio-based adhesive according to claim 1, characterized in that: The porous material has a diameter of 0.4-4.5 mm and a pore size of 0.05-400 μm; and / or the porous material is made of silicon dioxide.

9. The method for preparing a bio-based adhesive according to claim 1, characterized in that: The temperature in the columnar reaction channel is controlled to be 70-100° C., and the reaction residence time is 10-30 min; and / or the aspect ratio of the columnar reaction channel is 100-8000.

10. The method for preparing a bio-based adhesive according to claim 1, characterized in that: The total loading amount of the catalyst is 0.05%-1.0%, further 0.2%-0.5%, of the total mass of the bio-based polyol and the bio-based polyisocyanate in the flow channel chamber; and / or, the catalytic composite is formed by loading the catalyst on the porous material by impregnation; and / or, the hydroxyl value of the bio-based polyol is 170-400 mgKOH / g, the molecular weight is 100-2000 g / mol, and the viscosity is not more than 5000 mPa·s.

11. The method for preparing a bio-based adhesive according to claim 1, characterized in that: The bio-based adhesive is a one-component bio-based adhesive, and the implementation method of preparing the one-component bio-based adhesive includes: The bio-based polyol is pumped into a drying channel filled with a desiccant, and the dried bio-based polyol, bio-based polyisocyanate and a selective chain extender are respectively pumped into the columnar reaction channel to generate a bio-based polyurethane prepolymer, and then the bio-based polyurethane prepolymer is mixed with other raw materials to obtain the single-component bio-based adhesive.

12. The method for preparing a bio-based adhesive according to claim 11, characterized in that: In parts by weight, the one-component bio-based adhesive comprises: Bio-based polyol 32-50 parts 38-50 parts of bio-based polyisocyanate Chain extender 2-6 parts 1-25 parts of auxiliary agent; The auxiliary agent is a combination of one or more selected from anti-sagging agent, pigment, dispersant, antifungal agent, defoaming agent and flame retardant.

13. The method for preparing the bio-based adhesive according to any one of claims 1 to 12, characterized in that: The bio-based polyol is a combination of one or more selected from modified soybean oil with hydroxyl groups, BioPTMG polytetramethyl ether glycol, PO3G polytrimethylene ether glycol, HM-635S sorbitol polyether polyol, modified castor oil polyol, and palm oil polyol.

14. The method for preparing the bio-based adhesive according to any one of claims 1 to 12, characterized in that: The bio-based polyisocyanate is prepared by the following method: React 1,1-dimethyl-2,2,2-trichloroethoxycarbonyl chloride with sodium azide to generate a compound represented by formula (I); The compound represented by formula (I) is reacted with azelaic acid to generate a bio-based polyisocyanate represented by formula (II); wherein the azelaic acid is prepared by ozone decomposition of biomass acid; 15. A bio-based adhesive, characterized in that: The bio-based adhesive is prepared by the preparation method of the bio-based adhesive according to any one of claims 1 to 14.

Images