A kind of polyamide silane coupling agent and preparation method thereof

Abstract

The invention discloses a polyamide silane coupling agent and a preparation method thereof, comprising the following steps: S1. subjecting a polyamine compound, a dicarbonyl compound and a diprimary amine polyether to an amidation reaction to obtain a polyamide resin; S2. subjecting the polyamide resin to a substitution reaction with a silane coupling agent to obtain a polyamide silane coupling agent. The polyamide silane coupling agent proposed by the invention can not only reduce the amount of volatile organic solvent used when preparing an aqueous solution to reduce environmental pollution, but also improve the storage stability of the aqueous solution to overcome the shortcomings of the prior art, while improving the bonding strength between organic materials and inorganic materials.

Description

Technical Field

[0001] The invention relates to the technical field of polymer synthesis, and in particular to a polyamide silane coupling agent and a preparation method thereof. Background Art

[0002] Silane coupling agent, as a special organosilicon compound, has the general formula YR-SiX3. In this structure, X and Y represent groups with different reaction characteristics: X is usually alkoxy, acetoxy or halogen, etc., which can produce silanol (Si-OH) after hydrolysis, and the silanol can form a chemical bond with inorganic materials such as glass; Y is an organic group, such as vinyl, amino, epoxy or mercapto, etc., which can react with organic materials (such as resins, etc.) to enhance the reactivity and compatibility of silane coupling agent with organic materials. R is a carbon chain containing saturated or unsaturated bonds, connecting Y and Si atoms. It is precisely because of the presence of two functional groups with affinity for organic groups and affinity for inorganic groups in the silane coupling agent molecule that it is often used as a binder to connect inorganic materials and organic materials, bonding two materials of different properties to form a composite material of inorganic phase-silane coupling agent-organic phase, thereby improving the crack strength and toughness, heat resistance, cold resistance and corrosion resistance of the composite material.

[0003] Silane coupling agents are small organic molecules. In order to further improve their performance and expand their application areas, researchers generally modify them to obtain improved silane coupling agents with larger molecular weights. When the above-mentioned improved silane coupling agents are used as binders, they generally need to be prepared into aqueous solutions to meet the hydrolysis reaction and improve dispersibility. According to the difference in water solubility, the existing improved silane coupling agents mainly include the following two categories: (1) water-soluble type, which can form a stable dispersion system in water and can be directly prepared into aqueous solutions. This type of improved silane coupling agent generally contains a large number of primary and secondary amino groups. A large number of primary and secondary amino groups are easily protonated in aqueous solutions to form positively charged ions, thereby making the aqueous solution highly alkaline. The improved silane coupling agent can be self-catalytically hydrolyzed without the need for additional acid addition, and the improved silane coupling agent can be hydrolyzed in both acidic and alkaline environments. However, a strong alkaline environment will accelerate the hydrolysis of the improved silane coupling agent and the cross-linking reaction between the hydrolysis products of silanols, resulting in limited storage stability of its aqueous solution, which can usually only be stably stored for several weeks. (2) Poor water solubility. This type of improved silane coupling agent usually contains more hydrophobic groups and has low solubility in water. When preparing its aqueous solution, it is often necessary to add alcohol solvents to improve the dissolution stability, and it is necessary to add acid to the aqueous solution to catalyze hydrolysis. However, due to the structural characteristics of this type of improved silane coupling agent itself, even if a large amount of alcohol solvent is added, it is easy to precipitate from the aqueous solution and undergo cross-linking reaction, resulting in poor storage stability of the aqueous solution. In addition, since the aqueous solution contains a large amount of volatile organic solvents, it is easy to pollute the environment during use. Summary of the invention

[0004] The purpose of the present invention is to provide a polyamide silane coupling agent, which can not only reduce the amount of volatile organic solvent used when preparing an aqueous solution to reduce environmental pollution, but also improve the storage stability of the aqueous solution to overcome the shortcomings of the prior art while improving the bonding strength between organic materials and inorganic materials.

[0005] Another object of the present invention is to provide a method for preparing a polyamide silane coupling agent, which has simple steps and strong operability, and ensures that the obtained silane coupling agent can not only reduce the amount of volatile organic solvent used when it is prepared into an aqueous solution to reduce environmental pollution, but also improve the storage stability of its aqueous solution while improving the bonding strength between organic materials and inorganic materials.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A polyamide silane coupling agent having the structural formula shown in Formula I:

[0008]

[0009] Among them, the sum of x, y and z is 10-50, m is 1-8, and n is 2-10.

[0010] Furthermore, the x is 0-10, the y is 9-50, and the z is 0-10.

[0011] Furthermore, the m is 2-6, and the n is 3-8.

[0012] Furthermore, the weight average molecular weight of the polyamide silane coupling agent is 3000-6000.

[0013] Further, the R1 and the R2 are both C2-C3 alkylene;

[0014] R3 is any one of C1-C8 alkylene, alkenylene and cycloalkylene;

[0015] The R4 is any one of a C1-C3 alkylene group and an alkenylene group;

[0016] The R5 is any one of alkoxy, acetoxy and halogen.

[0017] A method for preparing a polyamide silane coupling agent, used for preparing the above-mentioned polyamide silane coupling agent, comprises the following steps:

[0018] S1. A polyamine compound, a dicarbonyl compound and a diprimary amine polyether are subjected to an amidation reaction to obtain a polyamide resin;

[0019] S2. Substitution reaction of a polyamide resin with a silane coupling agent to obtain a polyamide silane coupling agent;

[0020] In step S1, the polyamine compound has a structural formula shown in Formula II:

[0021]

[0022] The dicarbonyl compound has a structural formula shown in Formula III:

[0023]

[0024] The diprimary amine polyether has a structural formula shown in Formula IV:

[0025]

[0026] In step S2, the silane coupling agent has a structural formula shown in Formula V:

[0027]

[0028] X is any one of Cl, Br and I.

[0029] Further, in step S1, the molar ratio of the polyamine compound, the dicarbonyl compound and the diprimary amine polyether is (2.1-2.2):2:(0.8-1.0);

[0030] In step S2, the molar ratio of the polyamide resin to the silane coupling agent is 1:(5-10).

[0031] Furthermore, in step S1, the reaction temperature of the amidation reaction is 130-180° C., and the reaction time is 12-18 hours.

[0032] Furthermore, in step S2, the reaction temperature of the substitution reaction is 90-130° C., and the reaction time is 3-4 hours.

[0033] Furthermore, step S1 is specifically as follows:

[0034] Under nitrogen protection, a polyamine compound, a dicarbonyl compound and a diprimary amine polyether are subjected to an amidation reaction to obtain a polyamide resin mixture;

[0035] The polyamide resin mixture is distilled under reduced pressure for 3 to 4 hours under a vacuum environment, and then cooled to obtain a polyamide resin;

[0036] Step S2 is specifically as follows:

[0037] After the polyamide resin is completely dissolved in the solvent, a silane coupling agent is added to carry out a substitution reaction to obtain a polyamide silane coupling agent;

[0038] Wherein, the solvent is any one of methanol and ethanol.

[0039] The technical solution provided by the present invention may include the following beneficial effects:

[0040] 1. The polyamide silane coupling agent contains three ether groups: -OCH(CH3)CH2-, -OCH2CH2 and -OCH2CHCH3-. The oxygen atoms in the above three ether groups can form hydrogen bonds with water molecules. The above interaction makes the ether group hydrophilic, which is beneficial to improve the water solubility of the polyamide silane coupling agent. At the same time, as a flexible group, the ether group can change the conformation and flexibility of the polymer chain, making it easier for the polymer chain to contact and interact with water molecules, thereby improving its water solubility. In addition, the presence of the ether group can also increase the gap between the polymer molecular chains, which is beneficial to the penetration and diffusion of water molecules. When water molecules penetrate into the interior of the polymer, they can form hydrogen bonds with the ether group, further increasing the water solubility of the polymer. In addition, the sum of x, y and z is limited to 10 to 50, ensuring that the polyamide silane coupling agent contains a large number of ether groups, which is beneficial to ensuring the water solubility of the polyamide silane coupling agent. That is, the technical solution introduces the three ether groups -OCH(CH3)CH2-, -OCH2CH2 and -OCH2CHCH3-, makes full use of the multiple advantages of the above three ether groups, and limits the sum of the numbers of the above three ether groups, thereby greatly improving the water solubility of the polyamide silane coupling agent, which is beneficial to reducing the use of volatile organic solvents when it is prepared into an aqueous solution, so as to reduce environmental pollution.

[0041] 2. In view of the fact that the difficulty of protonation of primary amino groups, secondary amino groups and tertiary amine groups decreases in sequence, that is, their contribution to the alkalinity of aqueous solutions after protonation gradually weakens. In order to improve the storage stability of polyamide silane coupling agents, this technical solution grafts -R4-Si-(R5)3 groups to the primary amino groups in the polyamide silane coupling agent, so that the primary amino groups are converted into secondary amine groups with a lower degree of protonation; at the same time, the same silane group grafting is also performed on some secondary amine groups in the polyamide silane coupling agent, so that the secondary amino groups are further converted into tertiary amine groups with a lower degree of protonation. The above transformation effectively reduces the alkalinity of the aqueous solution of the polyamide silane coupling agent, thereby slowing down the rate of hydrolysis and cross-linking reactions, and significantly improving its storage stability.

[0042] 3. The technical solution limits the number of m to 1 to 8, so as to appropriately adjust the degree of conversion of secondary amino groups to tertiary amino groups, ensure that the alkalinity of the polyamide silane coupling agent aqueous solution is maintained at an appropriate level, and is conducive to effectively slowing down the hydrolysis and cross-linking reaction speed and improving the storage stability under the premise of ensuring self-hydrolysis catalysis. That is, through the above two effects, the storage stability of the polyamide silane coupling agent aqueous solution is improved. DETAILED DESCRIPTION

[0043] The present technical solution provides a polyamide silane coupling agent having a structural formula shown in Formula I:

[0044]

[0045] Among them, the sum of x, y and z is 10-50, m is 1-8, and n is 2-10.

[0046] In order to solve the defects that the existing improved silane coupling agent requires a large amount of volatile organic solvent when it is configured into an aqueous solution and its aqueous solution has poor storage stability, the technical solution proposes a polyamide silane coupling agent, which introduces amide groups and polyether groups, and combines the control of the protonation degree of the amino group. On the premise of improving the bonding strength between organic materials and inorganic materials, it can not only reduce the use of volatile organic solvents when it is prepared into an aqueous solution to reduce environmental pollution, but also improve the storage stability of its aqueous solution to meet actual usage needs.

[0047] Specifically, the polyamide silane coupling agent contains an amide group. The nitrogen atom and the carbonyl oxygen atom in the amide group can form hydrogen bonds with water molecules. The above interaction makes the amide group hydrophilic, which is beneficial to improve the water solubility of the polyamide silane coupling agent, thereby reducing the amount of volatile organic solvent used when preparing the aqueous solution of the polyamide silane coupling agent, thereby reducing pollution to the environment.

[0048] At the same time, the polyamide silane coupling agent contains three ether groups, namely -OCH(CH3)CH2-, -OCH2CH2 and -OCH2CHCH3-. The oxygen atoms in the above three ether groups can form hydrogen bonds with water molecules. The above interaction makes the ether group hydrophilic, which is beneficial to improve the water solubility of the polyamide silane coupling agent. At the same time, as a flexible group, the ether group can change the conformation and flexibility of the polymer chain, making the polymer chain more likely to contact and interact with water molecules, thereby improving its water solubility. In addition, the presence of the ether group can also increase the gap between the polymer molecular chains, which is beneficial to the penetration and diffusion of water molecules. When water molecules penetrate into the interior of the polymer, they can form hydrogen bonds with the ether group, further increasing the water solubility of the polymer. In addition, the sum of x, y and z is limited to 10 to 50, ensuring that the polyamide silane coupling agent contains a large number of ether groups, which is beneficial to ensuring the water solubility of the polyamide silane coupling agent. That is, the technical solution introduces the three ether groups -OCH(CH3)CH2-, -OCH2CH2 and -OCH2CHCH3-, makes full use of the multiple advantages of the above three ether groups, and limits the sum of the numbers of the above three ether groups, thereby greatly improving the water solubility of the polyamide silane coupling agent, which is beneficial to reducing the use of volatile organic solvents when it is prepared into an aqueous solution, so as to reduce environmental pollution.

[0049] In summary, the technical solution greatly improves the water solubility of the polyamide silane coupling agent by introducing amide groups and ether groups and limiting the number of ether groups, which is beneficial to reducing the amount of volatile organic solvents used when preparing the aqueous solution, thereby reducing environmental pollution.

[0050] More specifically, if the improved silane coupling agent has good water solubility, it often contains primary amino groups and secondary amino groups. The above two amine groups are easily protonated in aqueous solution to form positively charged ions, giving the aqueous solution alkaline properties. When the number of primary amino groups and secondary amino groups is too large, the aqueous solution will be forced to present a strong alkaline environment, and the strong alkaline environment will accelerate the hydrolysis of the improved silane coupling agent and the cross-linking reaction between the hydrolysis products of silanols, resulting in limited storage stability of the improved silane coupling agent aqueous solution, which can usually only be stably stored for several weeks. Therefore, the present technical solution cannot be designed based on the above principle.

[0051] Given that the ease of protonation of primary amino groups, secondary amino groups, and tertiary amine groups decreases in sequence, that is, their contribution to the alkalinity of aqueous solutions after protonation gradually weakens. In order to improve the storage stability of polyamide silane coupling agents, this technical solution grafts -R4-Si-(R5)3 groups to the primary amino groups in the polyamide silane coupling agent, so that the primary amino groups are converted into secondary amine groups with a lower degree of protonation; at the same time, the same silane group grafting is performed on some secondary amine groups in the polyamide silane coupling agent, so that the secondary amino groups are further converted into tertiary amine groups with a lower degree of protonation. The above transformation effectively reduces the alkalinity of the aqueous solution of the polyamide silane coupling agent, thereby slowing down the rate of hydrolysis and cross-linking reactions, and significantly improving its storage stability.

[0052] In addition, the technical solution limits the number of m to 1 to 8, so as to appropriately adjust the degree of conversion of secondary amino groups to tertiary amino groups, ensure that the alkalinity of the polyamide silane coupling agent aqueous solution is maintained at an appropriate level, and is conducive to effectively slowing down the hydrolysis and cross-linking reaction speeds and improving storage stability under the premise of ensuring self-hydrolysis catalysis. That is, through the above two effects, the storage stability of the polyamide silane coupling agent aqueous solution is improved.

[0053] Further, the multiple secondary amine groups in the polyamide silane coupling agent of the technical solution not only maintain the reactivity with organic materials (such as epoxy resin and organic acid), but also enhance the bonding strength with these materials. Meanwhile, the silane coupling agent is embedded in the polyamide silane coupling agent chain, which improves its molecular weight. Compared with small molecule aminosilane coupling agents, polyaminoamide silane coupling agents are more likely to interact, entangle or interpenetrate with the macromolecular chains of organic materials because of having longer molecular chains, thereby significantly enhancing the bonding strength with organic materials. In addition, multiple-R4-Si-(R5)3 groups in polyamide silane coupling agents also enhance their effective combination with inorganic materials through the bonding action between hydrolysis and its hydrolyzate and inorganic materials. That is, the polyamide silane coupling agent in the technical solution is conducive to increasing the bonding strength between inorganic materials and organic materials.

[0054] In addition, the multiple amide groups distributed on the polyamide silane coupling agent chain make it easier for the chain segments to move relative to each other, thereby increasing its flexibility. At the same time, the interaction between the amide groups and the formation of hydrogen bonds make the chain structure of the polyamide silane coupling agent more compact and orderly, which is conducive to improving its tensile strength and impact resistance.

[0055] To further illustrate, the x is 0-10, the y is 9-50, and the z is 0-10.

[0056] By optimizing x, y and z, suitable raw materials can be selected as needed, which improves the flexibility of the solution and helps to meet the needs of different application scenarios.

[0057] To further illustrate, m is 2-6, and n is 3-8.

[0058] Further optimizing the values ​​of m and n is beneficial to achieving better performance of the polyamide silane coupling agent and further improving the storage stability of the polyamide silane coupling agent aqueous solution.

[0059] It is further described that the weight average molecular weight of the polyamide silane coupling agent is 3000-6000.

[0060] Limiting the weight average molecular weight of the polyamide silane coupling agent is beneficial to improving the storage stability of its aqueous solution and the bonding strength between organic materials and inorganic materials at a lower cost.

[0061] Further description, said R1 and said R2 are both C2-C3 alkylene;

[0062] R3 is any one of C1-C8 alkylene, alkenylene and cycloalkylene;

[0063] The R4 is any one of a C1-C3 alkylene group and an alkenylene group;

[0064] The R5 is any one of alkoxy, acetoxy and halogen.

[0065] By optimizing the groups of R1, R2, R3, R4 and R5, not only can the appropriate raw materials be selected as needed, the flexibility of the scheme is improved, and it is conducive to meeting the needs of different application scenarios, but also the groups of R1, R2, R3, R4 and R5 are relatively common, which is conducive to ensuring the availability of raw materials and reducing the production difficulty and production cost of polyamide silane coupling agents.

[0066] Preferably, both R1 and R2 are ethylene;

[0067] R3 is any one of cyclohexylene, vinylene, ethylene, propylene, butylene and octylene;

[0068] The R4 is any one of vinylene, ethylene and propylene;

[0069] The R5 is any one of a methoxy group, an ethoxy group and a chloro group.

[0070] A method for preparing a polyamide silane coupling agent, used for preparing the above-mentioned polyamide silane coupling agent, comprises the following steps:

[0071] S1. A polyamine compound, a dicarbonyl compound and a diprimary amine polyether are subjected to an amidation reaction to obtain a polyamide resin;

[0072] S2. Substitution reaction of a polyamide resin with a silane coupling agent to obtain a polyamide silane coupling agent;

[0073] In step S1, the polyamine compound has a structural formula shown in Formula II:

[0074]

[0075] The dicarbonyl compound has a structural formula shown in Formula III:

[0076]

[0077] The diprimary amine polyether has a structural formula shown in Formula IV:

[0078]

[0079] In step S2, the silane coupling agent has a structural formula shown in Formula V:

[0080]

[0081] X is any one of Cl, Br and I.

[0082] The technical solution also proposes a method for preparing a polyamide silane coupling agent. The preparation method is simple and easy to operate, ensuring that the obtained silane coupling agent can not only reduce the amount of volatile organic solvent used when it is prepared into an aqueous solution to reduce environmental pollution, but also improve the storage stability of its aqueous solution while improving the bonding strength between organic materials and inorganic materials.

[0083] Specifically, the specific reaction of step S1 in this technical solution is as follows:

[0084]

[0085] The specific reaction of step S2 is as follows:

[0086]

[0087] Preferably, R6 is any one of hydroxyl, methoxy, ethoxy and propoxy.

[0088] Further, in step S1, the molar ratio of the polyamine compound, the dicarbonyl compound and the diprimary amine polyether is (2.1-2.2):2:(0.8-1.0);

[0089] In step S2, the molar ratio of the polyamide resin to the silane coupling agent is 1:(5-10).

[0090] The technical solution limits the molar ratio of the polyamine compound, the dicarbonyl compound and the diprimary amine polyether, and the polyamine compound is slightly excessive, which is beneficial to ensure that the polymer obtained from the polyamine compound, the dicarbonyl compound and the diprimary amine polyether is produced as expected, thereby improving the purity and yield of the target product polyamide resin.

[0091] Furthermore, the technical solution limits the molar ratio of the polyamide resin and the silane coupling agent, which is conducive to ensuring the substitution reaction between the polyamide resin and the silane coupling agent, ensuring that the reaction proceeds as expected, and the reaction is complete.

[0092] Further, in step S1, the reaction temperature of the amidation reaction is 130-180° C., and the reaction time is 12-18 hours.

[0093] The amidation reaction is a reversible reaction. When the reaction temperature of the amidation reaction is too low and the reaction time is too short, the reaction degree is low and the product yield is low; when the reaction temperature of the amidation reaction is too high and the reaction time is too long, the reaction degree and the product yield increase are not obvious, and the production cost is greatly increased and the production efficiency is reduced. The technical solution is conducive to increasing the product yield while reducing the production cost and improving the production efficiency by limiting the reaction temperature and reaction time.

[0094] Further, in step S2, the reaction temperature of the substitution reaction is 90-130° C., and the reaction time is 3-4 h.

[0095] When the reaction temperature of the substitution reaction is too low and the reaction time is too short, the reaction degree is low and the product yield is low; when the reaction temperature of the substitution reaction is too high and the reaction time is too long, the reaction degree and the product yield increase are not obvious, and the production cost is greatly increased and the production efficiency is reduced. The technical solution limits the reaction temperature and reaction time of the substitution reaction, which is conducive to increasing the product yield while reducing the production cost and improving the production efficiency.

[0096] To further illustrate, step S1 is specifically:

[0097] Under nitrogen protection, a polyamine compound, a dicarbonyl compound and a diprimary amine polyether are subjected to an amidation reaction to obtain a polyamide resin mixture;

[0098] The polyamide resin mixture is distilled under reduced pressure for 3 to 4 hours under a vacuum environment, and then cooled to obtain a polyamide resin;

[0099] Step S2 is specifically as follows:

[0100] After the polyamide resin is completely dissolved in the solvent, a silane coupling agent is added to carry out a substitution reaction to obtain a polyamide silane coupling agent;

[0101] Wherein, the solvent is any one of methanol and ethanol.

[0102] Carrying out the reaction under nitrogen protection is not only beneficial to prevent oxygen in the air from oxidizing the polyamine compound and the dicarbonyl compound, thereby affecting the reaction and the purity of the product, but also can remove some by-products through nitrogen, further improving the purity of the product. In addition, by distilling the polyamide resin mixture under vacuum for 3 to 4 hours, it is beneficial to remove by-products in the reaction process, which is also beneficial to improving the purity of the polyamide resin.

[0103] Furthermore, in order to promote the chemical reaction between the polyamide resin and the silane coupling agent, the present technical solution completely dissolves the solid polyamide resin in the solvent before the substitution reaction, thereby ensuring uniform dispersion of the polyamide resin molecules in the solvent and creating favorable conditions for the substitution reaction.

[0104] In addition, the chemical reaction between polyamide resin and silane coupling agent is highly complete, and the two can be efficiently combined to generate high-purity polyamide silane coupling agent, which simplifies the subsequent processing process and ensures the quality of the product. Given that the polyamide silane coupling agent needs to be used in the form of an aqueous solution and the product already has high purity, this solution does not arrange additional purification steps during the preparation process, avoiding unnecessary resource consumption and cost increase.

[0105] Preferably, in step S1, the vacuum degree of the vacuum environment is 0.05-0.1 MPa.

[0106] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0107] Example 1

[0108] S1. Under nitrogen protection, triethylenetetramine, diethyl maleate and polyetheramine ED-600 were reacted at 160°C for 15 hours to obtain a polyamide resin mixture; the polyamide resin mixture was subjected to reduced pressure distillation at a vacuum degree of 0.1 MPa for 4 hours, and then cooled to obtain a polyamide resin; wherein the molar ratio of triethylenetetramine, diethyl maleate and polyetheramine ED-600 was 2.1:2:0.8;

[0109] S2. After the polyamide resin is completely dissolved in methanol, 3-chloropropyltrimethoxysilane is added and reacted at 95° C. for 3 hours to obtain a polyamide silane coupling agent with a weight average molecular weight of 3260; wherein the molar ratio of the polyamide resin to the 3-chloropropyltrimethoxysilane is 1:5.

[0110] Example 2

[0111] S1. Under nitrogen protection, diethylenetriamine, dimethyl succinate and polyetheramine ED900 were reacted at 180°C for 13 hours to obtain a polyamide resin mixture; the polyamide resin mixture was subjected to reduced pressure distillation at a vacuum degree of 0.05 MPa for 3 hours, and then cooled to obtain a polyamide resin; wherein the molar ratio of diethylenetriamine, dimethyl succinate and polyetheramine ED900 was 2.2:2:1;

[0112] S2. After the polyamide resin is completely dissolved in ethanol, 3-chloropropyltriethoxysilane is added and reacted at 100° C. for 3 hours to obtain a polyamide silane coupling agent with a weight average molecular weight of 4180; wherein the molar ratio of the polyamide resin to the 3-chloropropyltriethoxysilane is 1:6.

[0113] Example 3

[0114] S1. Under nitrogen protection, tetraethylene pentamine, glutaric acid and polyetheramine ED-2003 were reacted at 170°C for 15 hours to obtain a polyamide resin mixture; the polyamide resin mixture was subjected to reduced pressure distillation at a vacuum degree of 0.08 MPa for 3.5 hours, and then cooled to obtain a polyamide resin; wherein the molar ratio of tetraethylene pentamine, glutaric acid and polyetheramine ED-2003 was 2.1:2:0.9;

[0115] S2. After the polyamide resin is completely dissolved in ethanol, 3-chloropropyltripropylsilane is added and reacted at 100°C for 3 hours to obtain a polyamide silane coupling agent with a weight average molecular weight of 5110; wherein the molar ratio of the polyamide resin to 3-bromopropyltriethoxysilane is 1:6.

[0116] Comparative Example 1

[0117] Comparative Example 1 has the same method and raw materials as Example 1, except that polyetheramine ED-600 is not added in step S1 of Comparative Example 1.

[0118] The polyamide silane coupling agent prepared in the embodiment and the comparative example was formulated into an aqueous solution with a mass concentration of 15%. According to the provisions of "GB 3186-1982 Sampling of Coating Products", three groups of samples were obtained. One group of samples was placed at room temperature for 1 day; another group of samples was placed at 50±2°C for 30 days; the remaining group of samples was placed at room temperature for 365 days; the appearance of the three groups of samples was observed, and the viscosity of the three groups of samples was tested, and the average value of the viscosity of each group of samples was taken as the viscosity test result. The test results are shown in Table 1 below.

[0119] In addition, the polyamide silane coupling agent aqueous solution configured in the comparative example and the embodiment was coated on the surface of the glass substrate and dried at 130°C for 10 hours to obtain a polyamide silane coupling agent coating; the bisphenol A type epoxy resin solution was coated on the polyamide silane coupling agent coating and dried at 160°C for 3 hours to obtain a composite material. The peel strength between the glass substrate and the bisphenol A type epoxy resin was measured using a tensile testing machine. The test results are shown in Table 1 below.

[0120] Table 1 Test results of relevant properties of polyamide silane coupling agent

[0121]

[0122] From the performance test results in the above table, it can be seen that the aqueous solution prepared by the polyamide silane coupling agent obtained in the embodiment of the technical scheme is placed at 50±2°C for 30 days and at room temperature for 365 days, and its appearance and viscosity do not change significantly. However, the aqueous solution prepared by the polyamide silane coupling agent obtained in Comparative Example 1 has a sharp increase in viscosity after being placed at 50±2°C for 30 days, and directly solidifies after being placed at room temperature for 365 days. It can be seen that the storage stability of the aqueous solution prepared by the polyamide silane coupling agent obtained in the embodiment of the technical scheme is higher than the storage stability of the aqueous solution prepared by the polyamide silane coupling agent obtained in the comparative example.

[0123] Furthermore, the peel strength between the glass substrate and the bisphenol A epoxy resin in the embodiment of the technical solution is significantly higher than the peel strength between the glass substrate and the bisphenol A epoxy resin in the comparative example. The peel strength between the glass substrate and the bisphenol A epoxy resin is closely related to the bonding strength between the glass substrate and the bisphenol A epoxy resin. When the peel strength between the glass substrate and the bisphenol A epoxy resin is greater, the bonding strength between the glass substrate and the bisphenol A epoxy resin is also greater, and vice versa. Therefore, it can be seen from the above that the polyamide silane coupling agent obtained by the preparation method of a polyamide silane coupling agent in the technical solution can not only reduce the use of volatile organic solvents when it is prepared into an aqueous solution to reduce environmental pollution, but also improve the storage stability of its aqueous solution, while improving the bonding strength between organic materials and inorganic materials.

[0124] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A polyamide silane coupling agent, characterized in that: It has the structural formula shown in Formula I: Among them, the sum of x, y and z is 10-50, m is 1-8, and n is 2-10.

2. A polyamide silane coupling agent according to claim 1, characterized in that: The x is 0-10, the y is 9-50, and the z is 0-10.

3. A polyamide silane coupling agent according to claim 1, characterized in that: The m is 2-6, and the n is 3-8.

4. A polyamide silane coupling agent according to claim 1, characterized in that: The weight average molecular weight of the polyamide silane coupling agent is 3000-6000.

5. A polyamide silane coupling agent according to claim 1, characterized in that: The R1 and R2 are both C2-C3 alkylene; R3 is any one of C1-C8 alkylene, alkenylene and cycloalkylene; The R4 is any one of a C1-C3 alkylene group and an alkenylene group; The R5 is any one of alkoxy, acetoxy and halogen.

6. A method for preparing a polyamide silane coupling agent, characterized in that: The method for preparing the polyamide silane coupling agent according to any one of claims 1 to 5 comprises the following steps: S1. A polyamine compound, a dicarbonyl compound and a diprimary amine polyether are subjected to an amidation reaction to obtain a polyamide resin; S2. Substitution reaction of a polyamide resin with a silane coupling agent to obtain a polyamide silane coupling agent; In step S1, the polyamine compound has a structural formula shown in Formula II: The dicarbonyl compound has a structural formula shown in Formula III: The diprimary amine polyether has a structural formula shown in Formula IV: In step S2, the silane coupling agent has a structural formula shown in Formula V: X is any one of Cl, Br and I.

7. The method for preparing a polyamide silane coupling agent according to claim 6, characterized in that: In step S1, the molar ratio of the polyamine compound, the dicarbonyl compound and the diprimary amine polyether is (2.1-2.2):2:(0.8-1.0); In step S2, the molar ratio of the polyamide resin to the silane coupling agent is 1:(5-10).

8. The method for preparing a polyamide silane coupling agent according to claim 6, characterized in that: In step S1, the reaction temperature of the amidation reaction is 130-180° C., and the reaction time is 12-18 hours.

9. The method for preparing a polyamide silane coupling agent according to claim 6, characterized in that: In step S2, the reaction temperature of the substitution reaction is 90-130° C., and the reaction time is 3-4 hours.

10. The method for preparing a polyamide silane coupling agent according to claim 6, characterized in that: Step S1 is specifically as follows: Under nitrogen protection, a polyamine compound, a dicarbonyl compound and a diprimary amine polyether are subjected to an amidation reaction to obtain a polyamide resin mixture; The polyamide resin mixture is distilled under reduced pressure for 3 to 4 hours under a vacuum environment, and then cooled to obtain a polyamide resin; Step S2 is specifically as follows: After the polyamide resin is completely dissolved in the solvent, a silane coupling agent is added to carry out a substitution reaction to obtain a polyamide silane coupling agent; Wherein, the solvent is any one of methanol and ethanol.

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