Two-component polyurethane adhesive with controllable open time, preparation method and application thereof

Abstract

This invention discloses a two-component polyurethane adhesive with controllable open time, its preparation method, and its applications. The two-component polyurethane adhesive with controllable open time includes a base adhesive and a curing agent; wherein the base adhesive is prepared from components including castor oil, polyether polyol A, modified diphenylmethane diisocyanate, chain extender A, and chain extender B, and the curing agent is prepared from components including isocyanate and polyether polyol B. The two-component polyurethane adhesive of this invention has a controllable open time and high shear strength, making it suitable for various applications, such as machine application and manual application.

Description

Technical Field

[0001] This invention relates to the field of polyurethane adhesives, specifically to a two-component polyurethane adhesive with controllable open time, its preparation method, and its application. Background Technology

[0002] As the intersection between various fields becomes increasingly deep, many adhesives, while meeting the requirements in specific scenarios, are difficult to adapt to new environments or situations due to varying usage conditions and scenarios. For example, when applying adhesives to a flat surface, machine application is often more convenient and faster to improve efficiency, requiring adhesives with shorter open times. In the same environment, however, if applying adhesives to a curved surface, machine application is difficult to achieve, necessitating the use of adhesives with longer open times to ensure smooth manual application.

[0003] Based on the above, there is an urgent need for an adhesive that can control the open time, so that it can be adapted to different scenarios in the same working environment, thereby saving product development costs and time costs. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a two-component polyurethane adhesive with controllable open time, its preparation method, and its application. Based on the relationship between the structure and properties of polyurethane, this invention regulates the reaction rate of polyurethane to make its open time controllable, and provides a method for preparing a two-component polyurethane adhesive with controllable open time.

[0005] One objective of this invention is to provide a two-component polyurethane adhesive with controllable open time, comprising a base adhesive and a curing agent. The base adhesive is prepared from components including castor oil, polyether polyol A, modified diphenylmethane diisocyanate, chain extender A, and chain extender B. The curing agent is prepared from components including isocyanate and polyether polyol B. The two-component polyurethane adhesive of this invention has controllable open time, making it primarily suitable for scenarios where the same product has different open time requirements, such as manual application versus machine application.

[0006] In a preferred embodiment of the present invention,

[0007] In the main adhesive:

[0008] The polyether polyol A is at least one selected from polyethylene oxide diol, polypropylene oxide diol, and polytetrahydrofuran diol, and / or, the number average molecular weight of the polyether polyol A is 400-4000 g / mol, preferably 600-1500 g / mol; preferably, the polyether polyol A is at least one selected from polypropylene oxide diol; and / or,

[0009] The modified diphenylmethane diisocyanate is at least one of carbodiimide-modified diphenylmethane diisocyanate (carbodiimide-modified MDI), polyol-modified diphenylmethane diisocyanate (polyol-modified MDI), and blended diphenylmethane diisocyanate (blended MDI), preferably carbodiimide-modified MDI, and more preferably carbodiimide-modified MDI from the brand name Texamodur CD-C; and / or,

[0010] The chain extender A is at least one of small molecule diols, preferably at least one of ethylene glycol, 1,4-butanediol, and hydroquinone dihydroxyethyl ether; and / or

[0011] The chain extender B is at least one of small molecule diamines, preferably at least one of 3,3'-dichloro-4,4'-diaminodiphenylmethane, diethyltoluenediamine, 4,4'-methylene-bis(3-chloro-2,6-diethylaniline), and 4,4'-bissec-butylaminodiphenylmethane, more preferably at least one of 3,3'-dichloro-4,4'-diaminodiphenylmethane and diethyltoluenediamine, and even more preferably 3,3'-dichloro-4,4'-diaminodiphenylmethane.

[0012] In a preferred embodiment of the present invention,

[0013] The components in the main adhesive are calculated based on castor oil in 100 parts by weight.

[0014] Polyether polyol A: 100-300 parts by weight; preferably 120-250 parts by weight;

[0015] 10-30 parts by weight of modified diphenylmethane diisocyanate; preferably 15-25 parts by weight;

[0016] Chain extender A: 10-20 parts by weight; preferably 10-15 parts by weight;

[0017] Chain extender B: 0.1-4.0 parts by weight; preferably 0.2-2.5 parts by weight. For example, the amount of chain extender B can be 0.2 parts by weight, 0.3 parts by weight, 0.4 parts by weight, 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, 1.0 parts by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight, 1.5 parts by weight, 1.6 parts by weight, 1.7 parts by weight, 1.8 parts by weight, 1.9 parts by weight, 2.0 parts by weight, 2.1 parts by weight, 2.2 parts by weight, 2.3 parts by weight, 2.4 parts by weight, 2.5 parts by weight, or any intermediate value between two values.

[0018] In a preferred embodiment of the present invention,

[0019] In the curing agent:

[0020] The isocyanate is at least one of aromatic isocyanates, aliphatic isocyanates, and alicyclic isocyanates, preferably at least one of aromatic isocyanates, more preferably at least one of diphenylmethane diisocyanate and polyphenylmethane polyisocyanate, for example, at least one of MDI-100, MDI-50, and PMDI; and / or

[0021] The polyether polyol B is at least one of polyethylene oxide diol, polypropylene oxide diol, and polytetrahydrofuran diol, and / or the number average molecular weight of the polyether polyol B is 400-2000 g / mol, preferably 400-600 g / mol; preferably, the polyether polyol B is at least one of polypropylene oxide diol.

[0022] In a preferred embodiment of the present invention,

[0023] The curing agent contains components in parts by weight of isocyanate, with each component comprising 100 parts by weight.

[0024] 30-50 parts by weight of polyether polyol B; preferably 35-45 parts by weight.

[0025] In a preferred embodiment of the present invention,

[0026] The raw materials for preparing the main adhesive also include at least one of the following: dehydrating agent A and adhesion promoter; and / or,

[0027] The raw materials for preparing the curing agent also include at least one of filler and dehydrating agent B;

[0028] Preferably,

[0029] The dehydrating agent A may be the same as or different from the dehydrating agent B, and each is independently at least one type of molecular sieve, preferably at least one type of 3a, 4a, or 5a molecular sieve; and / or,

[0030] The adhesion promoter is at least one of silane coupling agents and phthalate coupling agents, preferably at least one of silane coupling agents; and / or,

[0031] The filler is at least one of fumed silica, wollastonite, titanium dioxide, light calcium carbonate, heavy calcium carbonate, and quartz powder, preferably heavy calcium carbonate; preferably, the particle size of the filler is 0.001-100 μm. For example, the fumed silica can be selected from hydrophobic fumed silica from Hubei Huifu Nanomaterials Co., Ltd., the particle size of wollastonite is preferably <10 μm, the particle size of titanium dioxide is preferably 0.2-0.6 μm, the particle size of light calcium carbonate is preferably 0.02-1 μm, the particle size of heavy calcium carbonate is preferably 0.5-45 μm, and the particle size of quartz powder is preferably 150-500 μm.

[0032] In a preferred embodiment of the present invention,

[0033] When the raw materials for preparing the main adhesive also include at least one of dehydrating agent A and adhesion promoter, the amount of castor oil is calculated as 100 parts by weight.

[0034] Dehydrating agent A: 50-120 parts by weight; preferably 55-110 parts by weight; and / or,

[0035] 0.2-2 parts by weight of adhesion promoter; preferably 0.5-1 parts by weight.

[0036] In a preferred embodiment of the present invention,

[0037] When the raw materials for preparing the curing agent also contain at least one of filler and dehydrating agent B, the curing agent is prepared in parts by weight of isocyanate.

[0038] 60-110 parts by weight of filler; preferably 80-100 parts by weight; and / or,

[0039] Dehydrating agent B: 40-60 parts by weight; preferably 50-60 parts by weight.

[0040] In a preferred embodiment of the present invention,

[0041] The mass ratio of the main adhesive to the curing agent is (0.5-5):1, preferably (1-2):1.

[0042] The main adhesive described in this invention may also contain conventional additives in the art, such as polymerization inhibitors, and the dosage is also conventional. Those skilled in the art can add them according to the actual situation.

[0043] A second objective of this invention is to provide a method for preparing a two-component polyurethane adhesive with controllable open time, as described in one of the objectives of this invention, comprising:

[0044] Preparation of the main adhesive: includes the steps of reacting castor oil, polyether polyol A and modified diphenylmethane diisocyanate to obtain a hydroxyl-terminated polyurethane prepolymer, and then mixing the components including chain extender A, chain extender B and optional dehydrating agent A and adhesion promoter with the hydroxyl-terminated polyurethane prepolymer.

[0045] Preparation of curing agent: includes the steps of reacting isocyanate and polyether polyol B to obtain isocyanate-based end-capped polyurethane prepolymer, and then mixing the components including optional filler and dehydrating agent B with isocyanate-based end-capped polyurethane prepolymer.

[0046] In a preferred embodiment of the present invention,

[0047] In the preparation of the main adhesive, the reaction conditions include: a temperature of 70-90℃, and / or a time of 2-3 hours; and / or...

[0048] In the preparation of the curing agent, the reaction conditions include: a temperature of 70-90℃ and / or a time of 2-3 hours.

[0049] The present invention can adopt the following specific technical solutions:

[0050] The preparation method of the main adhesive includes: firstly, dehydrating polyether polyol A: placing polyether polyol A in a reaction vessel, stirring and heating to 110-120℃, evacuating to a vacuum degree of -0.095MPa, and then taking samples every 30 minutes to test the moisture content until the moisture content is below 1500ppm; then, according to the formula, reacting castor oil, polyether polyol A, and modified diphenylmethane diisocyanate at 70-90℃ for 2-3 hours, and obtaining a hydroxyl-terminated polyurethane prepolymer after the isocyanate groups have reacted completely; subsequently, mixing chain extender A, chain extender B, optional dehydrating agent A, and adhesion promoter with the hydroxyl-terminated polyurethane prepolymer evenly, degassing, filtering, and obtaining the main adhesive; the main adhesive needs to be sealed and stored.

[0051] The preparation method of the curing agent includes: firstly, dehydrating polyether polyol B: placing polyether polyol B in a reaction vessel, stirring and heating to 110-120℃, evacuating to a vacuum degree of -0.095MPa, and then taking samples every 30 minutes to test the moisture content until the moisture content is below 1500ppm; then reacting isocyanate and polyether polyol B at 70-90℃ for 2-3 hours according to the formula, and obtaining isocyanate-terminated polyurethane prepolymer after the hydroxyl groups have reacted completely; then mixing the optional filler and dehydrating agent B with the isocyanate-terminated polyurethane prepolymer evenly, degassing, filtering, and obtaining the curing agent; the curing agent needs to be sealed and stored.

[0052] A third objective of this invention is to provide an application of a two-component polyurethane adhesive with controllable open time, as described in one objective of this invention, or a two-component polyurethane adhesive with controllable open time prepared by the preparation method described in another objective of this invention, in the field of adhesives.

[0053] This invention regulates the reaction rate of polyurethane by adjusting the amount of small-molecule diamine added. On one hand, it induces the isocyanate groups to react with the amine groups to produce urea groups. On the other hand, the nitrogen-containing groups act as accelerators, promoting the reaction between the isocyanate groups and the hydroxyl groups. This two-way adjustment controls the open time of the polyurethane, making it controllable. The two-component polyurethane adhesive prepared by this invention can be used to adapt the application and splicing time of polyurethane adhesives, including different application scenarios for adhesives with the same performance, such as machine application and manual application. Detailed Implementation

[0054] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0055] Unless otherwise specified, the raw materials used in the embodiments of this invention are all publicly available in the prior art, and can be directly purchased or prepared according to the preparation methods disclosed in the prior art. Among them, the silane coupling agent is γ-aminopropyltriethoxysilane, brand name KH-550, purchased from Hangzhou Jessica Chemical Co., Ltd.; castor oil is purchased from SOLVAY; heavy calcium carbonate, model Omyacarb 2T-JI, is purchased from Omya; carbodiimide modified MDI, model Dexmodur CD-C; PMDI, model PM-200, is purchased from Shandong Wanhua; MDI-50 is purchased from Shandong Wanhua; and 3a, 4a, and 5a type molecular sieve activation powder is purchased from Jiangxi Xintao Technology Co., Ltd.

[0056] In this invention, the open time of the two-component polyurethane adhesive was determined according to the standard HG / T 3716-2013, "Determination of Open Time of Hot Melt Adhesives".

[0057] In this invention, the fully cured shear strength of the two-component polyurethane adhesive is determined according to the standard GB / T 7124-2008 Determination of tensile shear strength of adhesives (rigid material to rigid material).

[0058] Example 1

[0059] The components and weight proportions of the main adhesive are shown in Table 1 below:

[0060] Table 1

[0061] castor oil 100 parts by weight Polypropylene oxide diol (number average molecular weight 1000 g / mol) 250 parts by weight Carbodiimide-modified MDI 25 parts by weight Ethylene glycol 14 parts by weight Diethyltoluenediamine 2.5 parts by weight 3a molecular sieve 107.5 parts by weight Silane coupling agent 1 part by weight

[0062] The components and weight proportions of the curing agent are shown in Table 2 below:

[0063] Table 2

[0064] PMDI 100 parts by weight Polypropylene oxide diol (number average molecular weight 400 g / mol) 38.9 parts by weight 3a molecular sieve 55.6 parts by weight Heavy calcium carbonate 83.3 parts by weight

[0065] Preparation of two-component polyurethane adhesives with controllable open time:

[0066] Preparation of the main adhesive: First, the polyether polyol A was dehydrated: polyoxypropylene diol (1000 g / mol) was placed in a reaction vessel, stirred and heated to 120°C, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts castor oil, 250 parts polyoxypropylene diol (1000 g / mol), and 25 parts carbodiimide-modified MDI were reacted at 80°C for 2 hours. After the isocyanate groups had reacted completely, a hydroxyl-terminated polyurethane prepolymer was obtained. Subsequently, 14 parts ethylene glycol, 2.5 parts diethyltoluene diamine, 107.5 parts 3a molecular sieve, and 1 part silane coupling agent were mixed evenly with the hydroxyl-terminated polyurethane prepolymer, degassed, and filtered to obtain the main adhesive. The main adhesive was then sealed and stored.

[0067] Preparation of the curing agent: First, the polyether polyol B was dehydrated: polyoxypropylene diol (400 g / mol) was placed in a reaction vessel, stirred and heated to 120°C, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts of PMDI and 38.9 parts of polyoxypropylene diol (400 g / mol) were reacted at 80°C for 2 hours. After the hydroxyl groups had reacted completely, an isocyanate-terminated polyurethane prepolymer was obtained. Subsequently, 55.6 parts of 3a molecular sieve and 83.3 parts of heavy calcium carbonate were mixed evenly with the isocyanate-terminated polyurethane prepolymer, degassed, and filtered to obtain the curing agent. The curing agent was sealed and stored.

[0068] In the two-component polyurethane adhesive with controllable open time in Example 1, the mass mixing ratio of the main adhesive and the curing agent is 1.5:1.

[0069] Example 2

[0070] The components and weight proportions of the main adhesive are shown in Table 3 below:

[0071] Table 3

[0072] castor oil 100 parts by weight Polypropylene oxide diol (number average molecular weight 1000 g / mol) 250 parts by weight Carbodiimide-modified MDI 25 parts by weight 1,4-Butanediol 14.5 parts by weight 3,3'-Dichloro-4,4'-Diaminodiphenylmethane 2 parts by weight 4a molecular sieve 107.5 parts by weight Silane coupling agent 1 part by weight

[0073] The components and weight proportions of the curing agent are shown in Table 4 below:

[0074] Table 4

[0075] PMDI 100 parts by weight Polypropylene oxide diol (number average molecular weight 400 g / mol) 38.9 parts by weight 4a molecular sieve 55.6 parts by weight Heavy calcium carbonate 83.3 parts by weight

[0076] Preparation of two-component polyurethane adhesives with controllable open time:

[0077] Preparation of the main adhesive: First, the polyether polyol A was dehydrated: polyoxypropylene diol (1000 g / mol) was placed in a reaction vessel, stirred and heated to 120℃, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts castor oil, 250 parts polyoxypropylene diol (1000 g / mol), and 25 parts carbodiimide-modified MDI were reacted at 80℃ for 2 hours. After the isocyanate groups had reacted completely, a hydroxyl-terminated polyurethane prepolymer was obtained. Subsequently, 14.5 parts 1,4-butanediol, 2 parts 3,3'-dichloro-4,4'-diaminodiphenylmethane, 107.5 parts 4a molecular sieve, and 1 part silane coupling agent were mixed evenly with the hydroxyl-terminated polyurethane prepolymer, degassed, and filtered to obtain the main adhesive. The main adhesive was then sealed and stored.

[0078] Preparation of the curing agent: First, the polyether polyol B was dehydrated: polyoxypropylene diol (400 g / mol) was placed in a reaction vessel, stirred and heated to 120°C, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts of PMDI and 38.9 parts of polyoxypropylene diol (400 g / mol) were reacted at 80°C for 2 hours. After the hydroxyl groups had reacted completely, an isocyanate-terminated polyurethane prepolymer was obtained. Subsequently, 55.6 parts of 4a molecular sieve and 83.3 parts of heavy calcium carbonate were mixed evenly with the isocyanate-terminated polyurethane prepolymer, degassed, and filtered to obtain the curing agent. The curing agent was sealed and stored.

[0079] In the two-component polyurethane adhesive with controllable open time in Example 2, the mass mixing ratio of the main adhesive and the curing agent is 1.5:1.

[0080] Example 3

[0081] The components and weight proportions of the main adhesive are shown in Table 5 below:

[0082] Table 5

[0083] castor oil 100 parts by weight Polypropylene oxide diol (number average molecular weight 1000 g / mol) 125.8 parts by weight Carbodiimide-modified MDI 16.1 parts by weight 1,4-Butanediol 10 portions by weight Diethyltoluenediamine 0.65 parts by weight 5a molecular sieve 69.4 parts by weight Silane coupling agent 0.65 parts by weight

[0084] The components and weight proportions of the curing agent are shown in Table 6 below:

[0085] Table 6

[0086] MDI-50 100 parts by weight Polypropylene oxide diol (number average molecular weight 400 g / mol) 42.9 parts by weight 5a molecular sieve 57.2 parts by weight Heavy calcium carbonate 85.8 parts by weight

[0087] Preparation of two-component polyurethane adhesives with controllable open time:

[0088] Preparation of the main adhesive: First, the polyether polyol A was dehydrated: polyoxypropylene diol (1000 g / mol) was placed in a reaction vessel, stirred and heated to 120℃, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts castor oil, 125.8 parts polyoxypropylene diol (1000 g / mol), and 16.1 parts carbodiimide-modified MDI were reacted at 80℃ for 2 hours. After the isocyanate groups had reacted completely, a hydroxyl-terminated polyurethane prepolymer was obtained. Subsequently, 10 parts 1,4-butanediol, 0.65 parts diethyltoluene diamine, 69.4 parts 5a molecular sieve, and 0.65 parts silane coupling agent were mixed evenly with the hydroxyl-terminated polyurethane prepolymer, degassed, and filtered to obtain the main adhesive. The main adhesive was then sealed and stored.

[0089] Preparation of the curing agent: First, the polyether polyol B was dehydrated: polyoxypropylene diol (400 g / mol) was placed in a reaction vessel, stirred and heated to 120°C, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts of MDI-50 and 42.9 parts of polyoxypropylene diol (400 g / mol) were reacted at 80°C for 2 hours. After the hydroxyl groups had reacted completely, an isocyanate-terminated polyurethane prepolymer was obtained. Subsequently, 57.2 parts of 5a molecular sieve and 85.8 parts of heavy calcium carbonate were mixed evenly with the isocyanate-terminated polyurethane prepolymer, degassed, and filtered to obtain the curing agent. The curing agent was sealed and stored.

[0090] In the two-component polyurethane adhesive with controllable open time in Example 3, the mass mixing ratio of the main adhesive and the curing agent is 1.5:1.

[0091] Example 4

[0092] The components and weight proportions of the main adhesive are shown in Table 7 below:

[0093] Table 7

[0094] castor oil 100 parts by weight Polypropylene oxide diol (number average molecular weight 1000 g / mol) 125.8 parts by weight Carbodiimide-modified MDI 16.1 parts by weight Ethylene glycol 10.3 parts by weight 3,3'-Dichloro-4,4'-Diaminodiphenylmethane 0.32 parts by weight 3a molecular sieve 69.4 parts by weight Silane coupling agent 0.65 parts by weight

[0095] The components and weight proportions of the curing agent are shown in Table 8 below:

[0096] Table 8

[0097] MDI-50 100 parts by weight Polypropylene oxide diol (number average molecular weight 400 g / mol) 42.9 parts by weight 3a molecular sieve 57.2 parts by weight Heavy calcium carbonate 85.8 parts by weight

[0098] Preparation of two-component polyurethane adhesives with controllable open time:

[0099] Preparation of the main adhesive: First, the polyether polyol A was dehydrated: polyoxypropylene diol (1000 g / mol) was placed in a reaction vessel, stirred and heated to 120℃, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts castor oil, 125.8 parts polyoxypropylene diol (1000 g / mol), and 16.1 parts carbodiimide-modified MDI were reacted at 80℃ for 2 hours. After the isocyanate groups had reacted completely, a hydroxyl-terminated polyurethane prepolymer was obtained. Subsequently, 10.3 parts ethylene glycol, 0.32 parts 3,3'-dichloro-4,4'-diaminodiphenylmethane, 69.4 parts 3a molecular sieve, and 0.65 parts silane coupling agent were mixed evenly with the hydroxyl-terminated polyurethane prepolymer, degassed, and filtered to obtain the main adhesive. The main adhesive was then sealed and stored.

[0100] Preparation of the curing agent: First, the polyether polyol B was dehydrated: polyoxypropylene diol (400 g / mol) was placed in a reaction vessel, stirred and heated to 120°C, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts of MDI-50 and 42.9 parts of polyoxypropylene diol (400 g / mol) were reacted at 80°C for 2 hours. After the hydroxyl groups had reacted completely, an isocyanate-terminated polyurethane prepolymer was obtained. Subsequently, 57.2 parts of 3a molecular sieve and 85.8 parts of heavy calcium carbonate were mixed evenly with the isocyanate-terminated polyurethane prepolymer, degassed, and filtered to obtain the curing agent. The curing agent was sealed and stored.

[0101] In the two-component polyurethane adhesive with controllable open time in Example 4, the mass mixing ratio of the main adhesive and the curing agent is 1.5:1.

[0102] Example 5

[0103] The composition and weight percentages of the main adhesive are shown in Table 9 below:

[0104] Table 9

[0105] castor oil 100 parts by weight Polypropylene oxide diol (number average molecular weight 1000 g / mol) 125.8 parts by weight Carbodiimide-modified MDI 16.1 parts by weight Ethylene glycol 10.3 parts by weight Diethyltoluenediamine 0.32 parts by weight 3a molecular sieve 69.4 parts by weight Silane coupling agent 0.65 parts by weight

[0106] The components and weight proportions of the curing agent are shown in Table 10 below:

[0107] Table 10

[0108] MDI-50 100 parts by weight Polypropylene oxide diol (number average molecular weight 400 g / mol) 42.9 parts by weight 3a molecular sieve 57.2 parts by weight Heavy calcium carbonate 85.8 parts by weight

[0109] Preparation of two-component polyurethane adhesives with controllable open time:

[0110] Preparation of the main adhesive: First, the polyether polyol A was dehydrated: polyoxypropylene diol (1000 g / mol) was placed in a reaction vessel, stirred and heated to 120℃, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts castor oil, 125.8 parts polyoxypropylene diol (1000 g / mol), and 16.1 parts carbodiimide-modified MDI were reacted at 80℃ for 2 hours. After the isocyanate groups had reacted completely, a hydroxyl-terminated polyurethane prepolymer was obtained. Subsequently, 10.3 parts ethylene glycol, 0.32 parts diethyltoluene diamine, 69.4 parts 3a molecular sieve, and 0.65 parts silane coupling agent were mixed evenly with the hydroxyl-terminated polyurethane prepolymer, degassed, and filtered to obtain the main adhesive. The main adhesive was then sealed and stored.

[0111] Preparation of the curing agent: First, the polyether polyol B was dehydrated: polyoxypropylene diol (400 g / mol) was placed in a reaction vessel, stirred and heated to 120°C, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts of MDI-50 and 42.9 parts of polyoxypropylene diol (400 g / mol) were reacted at 80°C for 2 hours. After the hydroxyl groups had reacted completely, an isocyanate-terminated polyurethane prepolymer was obtained. Subsequently, 57.2 parts of 3a molecular sieve and 85.8 parts of heavy calcium carbonate were mixed evenly with the isocyanate-terminated polyurethane prepolymer, degassed, and filtered to obtain the curing agent. The curing agent was sealed and stored.

[0112] In the two-component polyurethane adhesive with controllable open time in Example 5, the mass mixing ratio of the main adhesive and the curing agent is 1.5:1.

[0113] Example 6

[0114] The components and weight proportions of the main adhesive are shown in Table 11 below:

[0115] Table 11

[0116]

[0117]

[0118] The components and weight proportions of the curing agent are shown in Table 12 below:

[0119] Table 12

[0120] MDI-50 100 parts by weight Polypropylene oxide diol (number average molecular weight 400 g / mol) 42.9 parts by weight 3a molecular sieve 57.2 parts by weight Heavy calcium carbonate 85.8 parts by weight

[0121] Preparation of two-component polyurethane adhesives with controllable open time:

[0122] Preparation of the main adhesive: First, the polyether polyol A was dehydrated: polyoxypropylene diol (1000 g / mol) was placed in a reaction vessel, stirred and heated to 120℃, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts castor oil, 125.8 parts polyoxypropylene diol (1000 g / mol), and 16.1 parts carbodiimide-modified MDI were reacted at 80℃ for 2 hours. After the isocyanate groups had reacted completely, a hydroxyl-terminated polyurethane prepolymer was obtained. Subsequently, 10.3 parts ethylene glycol, 0.1 parts 3,3'-dichloro-4,4'-diaminodiphenylmethane, 69.4 parts 3a molecular sieve, and 0.65 parts silane coupling agent were mixed evenly with the hydroxyl-terminated polyurethane prepolymer, degassed, and filtered to obtain the main adhesive. The main adhesive was then sealed and stored.

[0123] Preparation of the curing agent: First, the polyether polyol B was dehydrated: polyoxypropylene diol (400 g / mol) was placed in a reaction vessel, stirred and heated to 120°C, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts of MDI-50 and 42.9 parts of polyoxypropylene diol (400 g / mol) were reacted at 80°C for 2 hours. After the hydroxyl groups had reacted completely, an isocyanate-terminated polyurethane prepolymer was obtained. Subsequently, 57.2 parts of 3a molecular sieve and 85.8 parts of heavy calcium carbonate were mixed evenly with the isocyanate-terminated polyurethane prepolymer, degassed, and filtered to obtain the curing agent. The curing agent was sealed and stored.

[0124] In the two-component polyurethane adhesive with controllable open time in Example 6, the mass mixing ratio of the main adhesive and the curing agent is 1.5:1.

[0125] Example 7

[0126] The composition and weight percentages of the main adhesive are shown in Table 13 below:

[0127] Table 13

[0128] castor oil 100 parts by weight Polypropylene oxide diol (number average molecular weight 1000 g / mol) 125.8 parts by weight Carbodiimide-modified MDI 16.1 parts by weight Ethylene glycol 10.3 parts by weight 3,3'-Dichloro-4,4'-Diaminodiphenylmethane 4 parts by weight 3a molecular sieve 69.4 parts by weight Silane coupling agent 0.65 parts by weight

[0129] The components and weight proportions of the curing agent are shown in Table 14 below:

[0130] Table 14

[0131] MDI-50 100 parts by weight Polypropylene oxide diol (number average molecular weight 400 g / mol) 42.9 parts by weight 3a molecular sieve 57.2 parts by weight Heavy calcium carbonate 85.8 parts by weight

[0132] Preparation of two-component polyurethane adhesives with controllable open time:

[0133] Preparation of the main adhesive: First, the polyether polyol A was dehydrated: polyoxypropylene diol (1000 g / mol) was placed in a reaction vessel, stirred and heated to 120℃, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts castor oil, 125.8 parts polyoxypropylene diol (1000 g / mol), and 16.1 parts carbodiimide-modified MDI were reacted at 80℃ for 2 hours. After the isocyanate groups had reacted completely, a hydroxyl-terminated polyurethane prepolymer was obtained. Subsequently, 10.3 parts ethylene glycol, 4 parts 3,3'-dichloro-4,4'-diaminodiphenylmethane, 69.4 parts 3a molecular sieve, and 0.65 parts silane coupling agent were mixed evenly with the hydroxyl-terminated polyurethane prepolymer, degassed, and filtered to obtain the main adhesive. The main adhesive was then sealed and stored.

[0134] Preparation of the curing agent: First, the polyether polyol B was dehydrated: polyoxypropylene diol (400 g / mol) was placed in a reaction vessel, stirred and heated to 120°C, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts of MDI-50 and 42.9 parts of polyoxypropylene diol (400 g / mol) were reacted at 80°C for 2 hours. After the hydroxyl groups had reacted completely, an isocyanate-terminated polyurethane prepolymer was obtained. Subsequently, 57.2 parts of 3a molecular sieve and 85.8 parts of heavy calcium carbonate were mixed evenly with the isocyanate-terminated polyurethane prepolymer, degassed, and filtered to obtain the curing agent. The curing agent was sealed and stored.

[0135] In the two-component polyurethane adhesive with controllable open time in Example 7, the mass mixing ratio of the main adhesive and the curing agent is 1.5:1.

[0136] Comparative Example 1

[0137] The components and weight proportions of the main adhesive are shown in Table 15 below:

[0138] Table 15

[0139] castor oil 100 parts by weight Polypropylene oxide diol (number average molecular weight 1000 g / mol) 125.8 parts by weight Carbodiimide-modified MDI 16.1 parts by weight Ethylene glycol 10.3 parts by weight 3,3'-Dichloro-4,4'-Diaminodiphenylmethane 0 parts by weight 3a molecular sieve 69.4 parts by weight Silane coupling agent 0.65 parts by weight

[0140] The components and weight proportions of the curing agent are shown in Table 16 below:

[0141] Table 16

[0142]

[0143]

[0144] Preparation of two-component polyurethane adhesives:

[0145] Preparation of the main adhesive: First, the polyether polyol A was dehydrated: polyoxypropylene diol (1000 g / mol) was placed in a reaction vessel, stirred and heated to 120℃, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts castor oil, 125.8 parts polyoxypropylene diol (1000 g / mol), and 16.1 parts carbodiimide-modified MDI were reacted at 80℃ for 2 hours. After the isocyanate groups had reacted completely, a hydroxyl-terminated polyurethane prepolymer was obtained. Subsequently, 10.3 parts ethylene glycol, 69.4 parts 3a molecular sieve, and 0.65 parts silane coupling agent were mixed evenly with the hydroxyl-terminated polyurethane prepolymer, degassed, and filtered to obtain the main adhesive. The main adhesive was then sealed and stored.

[0146] Preparation of the curing agent: First, the polyether polyol B was dehydrated: polyoxypropylene diol (400 g / mol) was placed in a reaction vessel, stirred and heated to 120°C, and vacuumed to -0.095 MPa. Samples were taken every 30 minutes to test the moisture content until it was below 1000 ppm. Then, according to the formula, 100 parts of MDI-50 and 42.9 parts of polyoxypropylene diol (400 g / mol) were reacted at 80°C for 2 hours. After the hydroxyl groups had reacted completely, an isocyanate-terminated polyurethane prepolymer was obtained. Subsequently, 57.2 parts of 3a molecular sieve and 85.8 parts of heavy calcium carbonate were mixed evenly with the isocyanate-terminated polyurethane prepolymer, degassed, and filtered to obtain the curing agent. The curing agent was sealed and stored.

[0147] In the two-component polyurethane adhesive of Comparative Example 1, the mass mixing ratio of the main adhesive and the curing agent is 1.5:1.

[0148] The performance test results of the two-component polyurethane adhesives of Examples 1-7 and Comparative Example 1 are shown in Table 17.

[0149] Table 17

[0150]

[0151]

[0152] As can be seen from Examples 1-7, Comparative Example 1, and Table 17, in this invention, the reaction rate of polyurethane is controlled by adjusting the type and amount of small molecule diamines, thereby controlling the open time and making the open time controllable. Furthermore, in order to maintain high shear strength, it is preferable to use at least one of 3,3'-dichloro-4,4'-diaminodiphenylmethane and diethyltoluenediamine as the added small molecule diamine, more preferably using 3,3'-dichloro-4,4'-diaminodiphenylmethane as the added small molecule diamine; furthermore, in this invention, the amount of small molecule diamine (based on 100 parts by weight of castor oil) is preferably 0.1-4.0 parts by weight, more preferably 0.2-2.5 parts by weight.

[0153] The above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A two-component polyurethane adhesive with controllable open time, comprising a base adhesive and a curing agent; wherein, The main adhesive is prepared from components including castor oil, polyether polyol A, modified diphenylmethane diisocyanate, chain extender A and chain extender B, and the curing agent is prepared from components including isocyanate and polyether polyol B.

2. The two-component polyurethane adhesive as described in claim 1, characterized in that: In the main adhesive: The polyether polyol A is at least one selected from polyethylene oxide diol, polypropylene oxide diol, and polytetrahydrofuran diol, and / or the number average molecular weight of the polyether polyol A is 400-4000 g / mol; and / or, The modified diphenylmethane diisocyanate is at least one of carbodiimide-modified diphenylmethane diisocyanate, polyol-modified diphenylmethane diisocyanate, and blended diphenylmethane diisocyanate; and / or, The chain extender A is at least one of small molecule diols, preferably at least one of ethylene glycol, 1,4-butanediol, and hydroquinone dihydroxyethyl ether; and / or The chain extender B is at least one of small molecule diamines, preferably at least one of 3,3'-dichloro-4,4'-diaminodiphenylmethane, diethyltoluenediamine, 4,4'-methylene-bis(3-chloro-2,6-diethylaniline), and 4,4'-bissec-butylaminodiphenylmethane.

3. The two-component polyurethane adhesive as described in claim 1, characterized in that: The components in the main adhesive are calculated based on castor oil in 100 parts by weight. Polyether polyol A: 100-300 parts by weight; preferably 120-250 parts by weight; 10-30 parts by weight of modified diphenylmethane diisocyanate; preferably 15-25 parts by weight; Chain extender A: 10-20 parts by weight; preferably 10-15 parts by weight; Chain extender B: 0.1-4.0 parts by weight; preferably 0.2-2.5 parts by weight.

4. The two-component polyurethane adhesive as described in claim 1, characterized in that: In the curing agent: The isocyanate is at least one of aromatic isocyanates, aliphatic isocyanates, and alicyclic isocyanates, preferably at least one of aromatic isocyanates; and / or, The polyether polyol B is at least one of polyethylene oxide diol, polypropylene oxide diol, and polytetrahydrofuran diol, and / or the number average molecular weight of the polyether polyol B is 400-2000 g / mol.

5. The two-component polyurethane adhesive as described in claim 1, characterized in that: The curing agent contains components in parts by weight of isocyanate, with each component comprising 100 parts by weight. 30-50 parts by weight of polyether polyol B; preferably 35-45 parts by weight.

6. The two-component polyurethane adhesive according to any one of claims 1-5, characterized in that: The raw materials for preparing the main adhesive also include at least one of the following: dehydrating agent A and adhesion promoter; and / or, The raw materials for preparing the curing agent also include at least one of filler and dehydrating agent B; Preferably, The dehydrating agent A may be the same as or different from the dehydrating agent B, and each is independently at least one type of molecular sieve, preferably at least one type of 3a, 4a, or 5a molecular sieve; and / or, The adhesion promoter is at least one of silane coupling agents and phthalate coupling agents; and / or, The filler is at least one of fumed silica, wollastonite, titanium dioxide, light calcium carbonate, heavy calcium carbonate, and quartz powder.

7. The two-component polyurethane adhesive according to any one of claims 1-5, characterized in that: The mass ratio of the main adhesive to the curing agent is (0.5-5):1, preferably (1-2):

1.

8. A method for preparing a two-component polyurethane adhesive as described in any one of claims 1-7, comprising: Preparation of the main adhesive: includes the steps of reacting castor oil, polyether polyol A and modified diphenylmethane diisocyanate to obtain a hydroxyl-terminated polyurethane prepolymer, and then mixing the components including chain extender A, chain extender B and optional dehydrating agent A and adhesion promoter with the hydroxyl-terminated polyurethane prepolymer. Preparation of curing agent: includes the steps of reacting isocyanate and polyether polyol B to obtain isocyanate-based end-capped polyurethane prepolymer, and then mixing the components including optional filler and dehydrating agent B with isocyanate-based end-capped polyurethane prepolymer.

9. The preparation method according to claim 8, characterized in that: In the preparation of the main adhesive, the reaction conditions include: a temperature of 70-90℃, and / or a time of 2-3 hours; and / or... In the preparation of the curing agent, the reaction conditions include: a temperature of 70-90℃ and / or a time of 2-3 hours.

10. The application of a two-component polyurethane adhesive according to any one of claims 1-7 or a two-component polyurethane adhesive prepared by any one of claims 8-9 in the field of adhesives.

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