Modified radix asparagi polyurea coating composition

Abstract

The invention provides a modified radix asparagi polyurea coating composition, and relates to the technical field of radix asparagi polyurea. In the component A of the modified aspartic polyurea coating composition disclosed by the invention, the first aspartic ester resin containing a plurality of secondary amino groups and alkoxy silicon groups is used as matrix resin or one of the matrix resin, so that the modified aspartic polyurea coating composition has relatively good adhesive force on an inorganic base material, especially a metal base material; and the adhesive force, the anti-corrosion effect and the like of the asparagine polyurea coating on an inorganic base material, especially a metal base material are optimized.

Description

Technical Field

[0001] The invention belongs to the technical field of aspartame polyurea and relates to a modified aspartame polyurea coating composition. Background Art

[0002] The surface anti-corrosion treatment of metals is very important for the application of metals. Taking inland containers as an example, existing inland containers are mainly used in C4 and below corrosion environments. The conventional anti-corrosion coating on the surface of the container is an epoxy primer plus a polyurethane topcoat. The process is relatively complex, the drying speed is slow, and the VOC emissions are high. The asparagus polyurea system has the characteristics of fast drying, low VOC, good weather resistance and good corrosion resistance, but the conventional asparagus resin (such as Feiyang Junyan's F420 resin) does not have high adhesion to the metal substrate. Therefore, the pre-treatment requirements for the metal substrate are relatively high, and the metal substrate needs to be deeply polished or sandblasted. Otherwise, the adhesion is insufficient and / or the coating life is insufficient, which leads to the limitation of asparagus resin in medium and light corrosion protection applications. In order to improve the adhesion of asparagus polyurea to the metal substrate, one modification method is to introduce an alkoxysilyl structure into the aspartic acid ester resin to improve the adhesion through double crosslinking of amino-isocyanate crosslinking and hydrolysis crosslinking of alkoxy in moisture. For example, Chinese patent CN109467571A discloses a siloxane-modified aspartic acid ester, which is obtained by reacting polyethylene polyamine with a diester of butenedioic acid through a Michael addition reaction, followed by a reaction with a silane coupling agent. Chinese patent CN117024729A discloses a high-adhesion polyaspartic acid ester, which is obtained by reacting maleic anhydride monoester with polyethylene glycol through an esterification reaction, followed by a Michael addition reaction with a silane coupling agent containing a primary amino group.

[0003] However, the applicant believes that the existing technology of silicone-modified aspartic acid ester resin needs to be further optimized. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a modified aspartame polyurea coating composition.

[0005] The technical solutions of the present invention are as follows:

[0006] A modified aspartame polyurea coating composition, consisting of component A and component B;

[0007] The raw material components of the A component include: first aspartic acid ester resin, and any one or more of fillers, pigments and additives;

[0008] The B component is an isocyanate curing agent;

[0009] The structure of the first aspartic acid ester resin is shown in the following formula (1):

[0010]

[0011] Among them, R1, R2, R3, R5, R6, R 11 、R 12 、R 13 、R 14 、R 15 and R 16 independently selected from C1-C4 alkyl, R7, R8 and R 10 independently selected from C1-C6 divalent alkyl, R4 selected from C1-C4 alkyl or C1-C4 alkoxy, R9 selected from C1-C4 alkyl, C1-C4 alkoxy or the structure shown in the following formula (2), a≥0, b≥0, a+b≤10, b / (a+b)≤0.5,

[0012]

[0013] Among them, R 17 Selected from C1-C6 divalent alkyl, R 18 and R 19 independently selected from C1-C4 alkyl groups.

[0014] Preferably, the values ​​of a and b satisfy: a≤7, b / (a+b)≤0.3.

[0015] Preferably, the values ​​of a and b satisfy: a≤7, b=0.

[0016] Preferably, R1, R2, R3, R5 and R6 are independently selected from methyl or ethyl.

[0017] Preferably, the first aspartic acid ester resin is obtained by Michael addition reaction of a primary amino polyamine compound corresponding to the structure shown in formula (1) with dialkyl maleate and / or dialkyl fumarate.

[0018] More preferably, the dialkyl maleate and / or the dialkyl fumarate is in excess relative to the primary amino groups in the primary amino polyamine compound.

[0019] Preferably, the raw material components of the A component include second-generation aspartic acid ester resin;

[0020] The structure of the second aspartic acid ester resin is shown in the following formula (3):

[0021]

[0022] Wherein, X is selected from an m-valent organic group with a molecular weight of 50-5000 and inert to the reaction with NCO groups at 100°C, m=2-4, R 20 and R 21 independently selected from C1-C4 alkyl groups.

[0023] More preferably, the weight of the second aspartic acid ester resin does not exceed 100% of the weight of the first aspartic acid ester resin.

[0024] Preferably, the auxiliary agent comprises a dispersant, and the acid value of the dispersant is 5-140 mgKOH / g.

[0025] Preferably, the equivalent ratio of the NH groups in the A component to the NCO groups in the B component is 1:0.8-1.2.

[0026] The beneficial effects of the present invention are:

[0027] (1) The present invention adopts a siloxane-modified aspartic acid ester resin generated by the reaction of oligoaminosiloxane and maleic acid ester as the first aspartic acid ester resin, and there is a dual curing reaction of room temperature curing of the aspartic acid resin with isocyanate and alkoxysilyl moisture absorption curing, which effectively improves the adhesion of the aspartic acid polyurea coating on inorganic substrates, especially the adhesion on low surface treated metal substrates.

[0028] (2) The modified asparagus polyurea coating composition of the present invention uses a dispersant with a certain acid value in component A, which is found to significantly promote the above-mentioned dual curing reaction, is beneficial to the establishment of early hardness and adhesion of the coating curing, and improves the production efficiency of the modified asparagus polyurea coating composition in practical applications. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further illustrated and described below through specific implementation methods.

[0030] In order to improve the adhesion of aspartame polyurea coating to inorganic substrates, especially metal substrates, and reduce the requirements for pretreatment of the metal substrate, the present invention provides a modified aspartame polyurea coating composition, which consists of component A and component B;

[0031] The raw materials of component A include: first aspartic acid ester resin, and any one or more of fillers, pigments and additives;

[0032] Component B is an isocyanate curing agent;

[0033] The structure of the first aspartic acid ester resin is shown in the following formula (1):

[0034]

[0035] Among them, R1, R2, R3, R5, R6, R 11 、R 12 、R 13 、R 14 、R 15 and R 16independently selected from C1-C4 alkyl, R7, R8 and R 10 independently selected from C1-C6 divalent alkyl, R4 selected from C1-C4 alkyl or C1-C4 alkoxy, R9 selected from C1-C4 alkyl, C1-C4 alkoxy or the structure shown in the following formula (2), a≥0, b≥0, a+b≤10, b / (a+b)≤0.5,

[0036]

[0037] Among them, R 17 Selected from C1-C6 divalent alkyl, R 18 and R 19 independently selected from C1-C4 alkyl groups.

[0038] The first aspartic acid ester resin of the present invention has the following structural characteristics: (1) It contains multiple NH groups and alkoxy groups directly bonded to Si. The NH groups can react with active groups such as isocyanate groups and produce crosslinks. When the alkoxy structure encounters moisture, it can undergo a hydrolysis condensation reaction and form a crosslinked structure. Therefore, the first aspartic acid ester resin of the present invention can undergo a double crosslinking reaction, thereby improving the adhesion to inorganic substrates, especially metal substrates, and avoiding the need for grinding or sandblasting the metal substrate during application; (2) It has polysiloxane as the main chain and has good high and low temperature resistance, flexibility, etc. Multiple aspartic acid ester structures are located on the side chains of the polysiloxane main chain and have a high degree of freedom. Therefore, the polysiloxane-modified aspartic acid ester resin of the present invention can synergistically exert the properties of polysiloxane and aspartic acid ester, and has good high and low temperature resistance, weather resistance, corrosion resistance, etc.

[0039] When component A contains fillers, there are no special restrictions on the fillers, which may be inorganic fillers or organic fillers, such as kaolin, talc, titanium dioxide, wollastonite, glass beads, zinc oxide, aluminum oxide, calcium oxide, calcium carbonate, mica powder, barium sulfate, PE micropowder, PTFE micropowder, etc., and the weight proportion of the fillers in component A may be 5-50%; when component A contains pigments, there are no special restrictions on the pigments, which may be inorganic pigments or organic dyes, such as phthalocyanine blue, phthalocyanine green, iron oxide red, carbon black, titanium dioxide, iron yellow, iron black, cobalt yellow, cobalt green, etc., and the weight proportion of the pigments in component A may be 0.5-5%; when component A contains additives, there are no special restrictions on the additives, which may be ultraviolet absorbers, leveling agents, wetting agents, defoaming agents, dispersants, anti-settling agents, thixotropic agents, antioxidants, water absorbents, anti-sagging agents, etc., and the weight proportion of the additives in component A may be 0.8-5%. In addition, the raw material components of component A may also include diluents, such as PMA, butyl acetate, etc.

[0040] In some embodiments, the values ​​of a and b satisfy: a≤7, b / (a+b)≤0.3. For example, the value of a can be any value among 0, 1, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, etc., or any value therebetween, without particular limitation; b / (a+b) represents the molar ratio of -SiR4R9O- segments in the first aspartic acid ester resin. When R9 is not the structure shown in formula (2), for example, R9 is a C1-C4 alkyl group, if the value of b / (a+b) is too high, it will affect the reactivity of the first aspartic acid ester resin and / or the crosslinking density of the coating after curing, which is not conducive to improving the adhesion of the coating. For example, the value of b / (a+b) can be any value among 0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, etc., or any value therebetween, without particular limitation.

[0041] In some embodiments, the values ​​of a and b satisfy: a≤7, b=0. For example, the value of a can be any value among 0, 1, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, etc., or any value therebetween, without particular limitation.

[0042] In some embodiments, R1, R2, R3, R5, and R6 are independently selected from methyl or ethyl.

[0043] In some embodiments, the first aspartic acid ester resin is obtained by a Michael addition reaction between a primary amino group-containing polyamine compound corresponding to the structure of formula (1) and a dialkyl maleate and / or a dialkyl fumarate. The preparation of aspartic acid ester resins by Michael addition reaction between a primary amino group and a dialkyl maleate and / or a dialkyl fumarate is well known to those skilled in the art.

[0044] Taking the structure shown in the above formula (1) where b=0 as an example, the primary amino polyamine compound has the structure shown in the following formula (4):

[0045]

[0046] Among them, a, R1, R2, R3, R5, R6, R7, R8 and R 10 The meaning is as above.

[0047] The primary amino polyamine compound represented by formula (4) has no particular limitation on its source. It can be obtained directly from the market, such as Jiangxi Hongbai New Materials Co., Ltd., or prepared according to existing technologies. For example, one preparation method can be: 3-aminopropyltrimethoxysilane is added to methoxyisopropanol, a catalyst and water are added, and the mixture is stirred at a temperature of 50°C to 60°C for 10h to 15h for hydrolysis, and then vacuum dehydration is performed to obtain a polyvalent primary amine polysiloxane. The catalyst can be acetic acid, organotin, etc., and the weight percentages of 3-aminopropyltrimethoxysilane, methoxyisopropanol, catalyst, and water can be (40-50)%: (40-50)%: (0-5)%: (5-16)%. By adjusting the weight percentage of water, different average polymerization degrees a can be obtained. For example, when a=1, the primary amino polyamine compound can be an aminopropyltrimethoxysilane trimer; when a=5, the primary amino polyamine compound can be an aminopropyltrimethoxysilane heptamer. In the above-mentioned method for preparing a primary amino polyamine compound, when aminopropylmethyldimethoxy is added to the raw materials, a -SiR4R9O- structure can be introduced into the primary amino polyamine compound, where R4 is a methyl group and R9 is -(CH2)3NH2. When dimethyldimethoxysilane is added to the raw materials, a -SiR4R9O- structure can be introduced into the primary amino polyamine compound, where both R4 and R9 are methyl groups. Therefore, primary amino polyamine compounds with different structures can be obtained by adjusting the raw material composition and ratio.

[0048] Primary amino polyamine compounds contain multiple primary amino groups, and the Michael addition reaction with dialkyl maleates and / or dialkyl fumarates is a technique well known to those skilled in the art. Taking the primary amino polyamine compound represented by formula (4) as an example, the primary amino polyamine compound and dialkyl maleate (e.g., diethyl maleate) are placed in a molar ratio of 1:(1-1.1)(a+2) into a reaction vessel, heated to 70-100°C, reacted for 72-144 hours, and then purified using a short-path evaporator to obtain the first aspartic acid ester resin.

[0049] There is no particular limitation on the dialkyl maleate and / or dialkyl fumarate, and the dialkyl maleate may be diethyl maleate, dimethyl maleate, dibutyl maleate, diethyl fumarate, or the like.

[0050] In some embodiments, the dialkyl maleate and / or dialkyl fumarate is in excess relative to the primary amino groups in the primary amino polyamine compound, which is beneficial to the complete reaction of the primary amino groups in the primary amino polyamine compound, so that the primary amino polyamine compound is converted into the first aspartic acid ester resin as completely as possible. The excess dialkyl maleate and / or dialkyl fumarate can be removed by a short-path evaporator.

[0051] In some embodiments, the raw material components of the A component include a second aspartic acid ester resin;

[0052] The structure of the second aspartic acid ester resin is shown in the following formula (3):

[0053]

[0054] Wherein, X is selected from an m-valent organic group with a molecular weight of 50-5000 and inert to the reaction with NCO groups at 100°C, m=2-4, R 20 and R 21 independently selected from C1-C4 alkyl groups.

[0055] Including a second aspartic acid resin in the raw materials of Component A can reduce the cost and adjust the performance of Component A while still utilizing the properties of the first aspartic acid resin. The second aspartic acid resin can be prepared using conventional methods or directly obtained commercially, such as Feiyang Junyan's F420 resin, F520 resin, F421 resin, F220 resin, F330 resin, F221 resin, and F423 resin, without particular limitation.

[0056] In some embodiments, the weight of the second aspartic acid resin does not exceed 100% of the weight of the first aspartic acid resin. If the weight of the second aspartic acid resin is too large, it may be detrimental to the effect of the first aspartic acid resin in improving the adhesion of the inorganic substrate. For example, the weight of the second aspartic acid resin can be any value of 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, etc., or any value in between, of the weight of the first aspartic acid resin.

[0057] In some embodiments, the auxiliary agent includes a dispersant, and the acid value of the dispersant is 5-140 mgKOH / g. Dispersants are generally used to disperse fillers to improve the dispersibility and stability of the filler in the coating composition. It was unexpectedly found in the present invention that when the acid value of the dispersant is within a certain range, it helps to accelerate the dual curing reaction, improve the hardness and adhesion of the coating in the early stage of curing, and is beneficial to improve production efficiency in practical applications. If the acid value of the dispersant is not enough, the effect of promoting the dual curing reaction is not obvious; if the acid value of the dispersant is too high, it will cause the dual curing reaction to be too fast, which is not conducive to the early adhesion of the coating. For example, the acid value of the dispersant can be any value among 5 mgKOH / g, 10 mgKOH / g, 15 mgKOH / g, 20 mgKOH / g, 30 mgKOH / g, 40 mgKOH / g, 50 mgKOH / g, 60 mgKOH / g, 70 mgKOH / g, 80 mgKOH / g, 90 mgKOH / g, 100 mgKOH / g, 110 mgKOH / g, 120 mgKOH / g, 130 mgKOH / g, 140 mgKOH / g, or any value therebetween. Further, the acid value of the dispersant can be 5-80 mgKOH / g. The present invention has no special requirements for the dispersant, and it can be a small molecule dispersant or a polymer dispersant.

[0058] In some embodiments, the equivalent ratio of the NH groups in component A to the NCO groups in component B is 1:0.8-1.2. For example, the equivalent ratio of the NH groups to the NCO groups can be any value among 1:0.8, 1:0.85, 1:0.9, 1:0.95, 1:1, 1:1.05, 1:1.1, 1:1.15, 1:1.2, etc., or any value in between. There are no particular limitations on the isocyanate curing agent, and it can be a diisocyanate monomer, such as IPDI, HMDI, HDI, etc., or an adduct of a diisocyanate monomer and a polymer diol (such as GB902-100 from Feiyang Junyan Co., Ltd.), or a trimer of a diisocyanate monomer, such as HDI trimer, IPDI trimer, etc.

[0059] The modified asparagus polyurea coating composition of the present invention can be prepared by uniformly mixing the raw materials of component A and then uniformly mixing with component B. The modified asparagus polyurea coating composition of the present invention can be applied to the substrate surface by roller coating, brush coating, spraying, or other techniques. To improve the solubility of the isocyanate curing agent in component B, the isocyanate curing agent can be pre-diluted with an organic solvent.

[0060] The technical solution of the present invention is further described and illustrated below based on various preparation examples and examples. Unless otherwise specified, the parts mentioned in the following preparation examples and examples are parts by weight.

[0061] Preparation Example 1-4 Preparation of the first aspartic acid ester resin

[0062] Preparation Example 1

[0063] Aminopropyltrimethoxysilane trimer (a=1 in the above formula (4), R1, R2, R3, R5 and R6 are all methyl, R7, R8 and R 10 The molar ratio of propylene glycol and diethyl maleate is 1:3.3.

[0064] Aminopropyltrimethoxysilane trimer and diethyl maleate were added to a reaction vessel and heated to 80°C for 72 hours. After the reaction, the product was evaporated through a short-path evaporator at 110°C and a vacuum of 4 Pa ​​to obtain the first aspartic acid ester resin, designated as resin S-1.

[0065] Preparation Example 2

[0066] Aminopropyltrimethoxysilane dimer (a=0 in the above formula (4), R1, R2, R3, R5 and R6 are all methyl, R7, R8 and R 10 The molar ratio of propylene glycol and dibutyl maleate is 1:2.1.

[0067] Aminopropyltrimethoxysilane dimer and dibutyl maleate were added to a reaction vessel and heated to 80°C for 96 hours. After the reaction, the product was evaporated through a short-path evaporator at 120°C and a vacuum of 6 Pa to obtain the first aspartic acid ester resin, designated as resin S-2.

[0068] Preparation Example 3

[0069] The molar ratio of aminopropyltrimethoxysilane polymer to diethyl maleate is 1:8.2.

[0070] The structure of aminopropyltrimethoxysilane polymer is:

[0071]

[0072] Aminopropyltrimethoxysilane polymer and diethyl maleate were added to a reaction vessel and heated to 100°C for 120 hours. After the reaction, the product was evaporated through a short-path evaporator at 110°C and a vacuum of 5 Pa to obtain the first aspartic acid ester resin, designated as resin S-3.

[0073] Preparation Example 4

[0074] The molar ratio of aminopropyltrimethoxysilane polymer to diethyl maleate is 1:11.

[0075] The structure of aminopropyltrimethoxysilane polymer is:

[0076]

[0077] Aminopropyltrimethoxysilane polymer and diethyl maleate were added to a reaction vessel and heated to 100°C for 120 hours. After the reaction, the product was evaporated through a short-path evaporator at 120°C and a vacuum of 5 Pa to obtain the first aspartic acid ester resin, designated as resin S-4.

[0078] Comparative Preparation Example 1

[0079] The molar ratio of aminopropyltrimethoxysilane polymer to diethyl maleate is 1:5.3.

[0080] The structure of aminopropyltrimethoxysilane polymer is:

[0081]

[0082] Aminopropyltrimethoxysilane polymer and diethyl maleate were added to a reaction vessel and heated to 100°C for 120 hours. After the reaction, the product was evaporated through a short-path evaporator at 110°C and a vacuum of 5 Pa to obtain a siloxane-modified polyaspartic acid ester resin, designated as resin S-5.

[0083] Example 1

[0084] The raw material components of component A are composed of 40 parts of resin S-1 of Preparation Example 1, 1 part of dispersant BYK2013 (acid value 8 mgKOH / g), 0.6 parts of fumed silica R972, 0.2 parts of defoamer BYK1790, 0.1 parts of anti-sagging agent BYK410, 10 parts of aluminum zinc phosphomolybdate, 35 parts of titanium dioxide R-606, 3 parts of 3A molecular sieve, 0.1 parts of leveling agent EFKA FL3600, 0.9 parts of anti-aging agent 1130, 0.6 parts of anti-aging agent 292, 5 parts of butyl acetate and 3.5 parts of PMA.

[0085] The raw material composition of component B consists of 20 parts of HT-600, 60 parts of GB902-100, 10 parts of PMA and 10 parts of butyl acetate.

[0086] Component A and component B are uniformly mixed according to a molar ratio of NH group to NCO group of 1:1.05 to obtain a modified aspartame polyurea coating composition.

[0087] Example 2

[0088] The difference between this example and Example 1 is that in Example 1, the resin S-1 of Preparation Example 1 is replaced by an equal weight of the resin S-2 of Preparation Example 2. The remaining steps remain unchanged.

[0089] Example 3

[0090] The difference between this example and Example 1 is that in Example 1, the resin S-1 of Preparation Example 1 is replaced by an equal weight of the resin S-3 of Preparation Example 3. The remaining steps remain unchanged.

[0091] Example 4

[0092] The difference between this example and Example 1 is that in Example 1, the resin S-1 of Preparation Example 1 is replaced by an equal weight of the resin S-4 of Preparation Example 4. The remaining steps remain unchanged.

[0093] Comparative Example 1

[0094] The difference between this comparative example and Example 1 is that in Example 1, the resin S-1 of Preparation Example 1 is replaced by an equal weight combination of F420 resin and F520 resin in a weight ratio of 7:3. The remaining steps remain unchanged.

[0095] Comparative Example 2

[0096] The difference between this comparative example and comparative example 1 is that in Example 1, the resin S-1 of Preparation Example 1 is replaced by an equal weight of the resin S-5 of Comparative Preparation Example 1. The remaining steps remain unchanged.

[0097] Comparative Example 3

[0098] The difference between this comparative example and comparative example 1 is that in comparative example 1, the raw material components of component A further include 3 parts of 3-aminopropyltrimethoxysilane. The remaining steps remain unchanged.

[0099] Example 5

[0100] The difference between this example and Example 1 is that in Example 1, the resin S-1 of Preparation Example 1 is replaced by an equal weight combination of the resin S-1 of Preparation Example 1 and F520 resin in a weight ratio of 3:1. The remaining steps remain unchanged.

[0101] Example 6

[0102] The difference between this example and Example 1 is that in Example 1, the resin S-1 of Preparation Example 1 is replaced by an equal weight combination of the resin S-1 of Preparation Example 1 and F520 resin in a weight ratio of 1:1. The remaining steps remain unchanged.

[0103] Comparative Example 4

[0104] The difference between this comparative example and Example 1 is that in Example 1, the resin S-1 of Preparation Example 1 is replaced by an equal weight combination of the resin S-1 of Preparation Example 1 and F520 resin in a weight ratio of 1:2. The remaining steps remain unchanged.

[0105] The spray plate substrate was Q235 cold-rolled steel, which was degreased and air-dried with a detergent. A modified asparagus polyurea coating composition was sprayed onto the clean cold-rolled steel surface to a film thickness of approximately 100 μm. The pencil hardness of the coating was tested 6, 24, 48, and 168 hours after spraying. Adhesion was tested on a 100-grid scale after one day of room temperature curing. Follow-up adhesion tests were performed on days 2, 3, 5, and 7 (grade 0 is best, grade 5 is worst). The results are shown in Tables 1 and 2.

[0106] Table 1 Pencil hardness

[0107]

[0108] Table 2 Adhesion of 100 grids

[0109]

[0110] Combining the results of Tables 1 and 2 above, it can be seen that the early hardness of the different examples and comparative examples is different, but the hardness of the coating can all reach H after 7 days. The early adhesion of the different examples and comparative examples is different, and the adhesion after 7 days is also significantly different. Comparing Examples 1-4 and Comparative Examples 1-3, the use of the first aspartic acid ester resin of the present invention has good early adhesion and final adhesion, and the adhesion gradually improves as the curing is gradually completed. Comparing Example 5 and Example 6 with Comparative Example 4, the first aspartic acid ester resin is partially mixed with the second aspartic acid ester resin, and the weight proportion of the second aspartic acid ester resin exceeds 50%, and the adhesion will be significantly deteriorated.

[0111] Example 7

[0112] The difference between this embodiment and embodiment 1 is that in embodiment 1, BYK2013 is replaced by BYK110 (acid value 53 mgKOH / g) of equal weight, while the remaining steps remain unchanged.

[0113] Example 8

[0114] The difference between this embodiment and embodiment 1 is that in embodiment 1, BYK2013 is replaced by BYK111 (acid value 129 mgKOH / g) of equal weight, while the remaining steps remain unchanged.

[0115] Example 9

[0116] The difference between this embodiment and embodiment 1 is that in embodiment 1, BYK2013 is replaced by BYK163 (acid value 1 mgKOH / g) of equal weight, while the remaining steps remain unchanged.

[0117] Example 10

[0118] The difference between this embodiment and embodiment 1 is that in embodiment 1, BYK2013 is replaced by an equal weight of Hemmingsdecker Disponer 904S (acid value 200 mgKOH / g), and the remaining steps remain unchanged.

[0119] The adhesion and hardness properties of Examples 1, 7-10 are shown in Tables 3 and 4 below.

[0120] Table 3 Pencil hardness

[0121] Example 1 Example 7 Example 8 Example 9 Example 10 6h ＜B B HB ＜B HB 24h B HB H ＜B H 48h HB H H F H 168h H H H H H

[0122] Table 4 Adhesion of 100 grids

[0123] Example 1 Example 7 Example 8 Example 9 Example 10 1d Level 2 Level 1 Level 1 Level 3 Level 3 2d Level 2 Level 1 Level 2 Level 2 Level 4 3d Level 0 Level 0 Level 2 Level 2 Level 4 5d Level 0 Level 0 Level 2 Level 1 Level 4 7d Level 0 Level 0 Level 3 Level 1 Level 5

[0124] Combining the results of Tables 3 and 4, it can be seen that when the acid value of the dispersant is within a relatively suitable range, the hardness and adhesion of the coating can be quickly established as the acid value increases. Comparing Examples 1, 9, and 10, the acid value of the dispersant in Example 9 is very low, and the hardness and adhesion in the early stage of curing are slowly established. The acid value of the dispersant in Example 10 is too high, and the hardness in the early stage of curing is quickly established, but the adhesion in the early stage of curing is poor, and the final coating has poor adhesion.

[0125] As described above, the basic principles, main features, and advantages of the present invention are shown and described. Those skilled in the art should understand that the present invention is not limited to the above-described embodiments. The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. In other words, equivalent changes and modifications made within the scope of the present invention and the contents of the specification should still fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A modified aspartame polyurea coating composition, characterized in that: It consists of component A and component B; The raw material components of the A component include: first aspartic acid ester resin, and any one or more of fillers, pigments and additives; The B component is an isocyanate curing agent; The structure of the first aspartic acid ester resin is shown in the following formula (1): Among them, R1, R2, R3, R5, R6, R 11 、R 12 、R 13 、R 14 、R 15 and R 16 independently selected from C1-C4 alkyl, R7, R8 and R 10 independently selected from C1-C6 divalent alkyl, R4 selected from C1-C4 alkyl or C1-C4 alkoxy, R9 selected from C1-C4 alkyl, C1-C4 alkoxy or the structure shown in the following formula (2), a≥0, b≥0, a+b≤10, b / (a+b)≤0.5, Among them, R 17 Selected from C1-C6 divalent alkyl, R 18 and R 19 independently selected from C1-C4 alkyl groups.

2. The modified asparagus polyurea coating composition according to claim 1, characterized in that The values ​​of a and b satisfy: a≤7, b / (a+b)≤0.

3.

3. The modified asparagus polyurea coating composition according to claim 1, characterized in that The values ​​of a and b satisfy: a≤7, b=0.

4. The modified asparagus polyurea coating composition according to claim 1, characterized in that The R1, R2, R3, R5 and R6 are independently selected from methyl or ethyl.

5. The modified asparagus polyurea coating composition according to claim 1, characterized in that The first aspartic acid ester resin is obtained by Michael addition reaction of a primary amino polyamine compound corresponding to the structure shown in formula (1) with dialkyl maleate and / or dialkyl fumarate.

6. The modified aspartame polyurea coating composition according to claim 5, characterized in that: The dialkyl maleate or the dialkyl fumarate is in excess relative to the primary amino groups in the primary amino polyamine compound.

7. The modified asparagus polyurea coating composition according to claim 1, characterized in that: The raw material components of the A component include second aspartic acid ester resin; The structure of the second aspartic acid ester resin is shown in the following formula (3): Wherein, X is selected from an m-valent organic group with a molecular weight of 50-5000 and inert to the reaction with NCO groups at 100°C, m=2-4, R 20 and R 21 independently selected from C1-C4 alkyl groups.

8. The modified asparagus polyurea coating composition according to claim 7, characterized in that: The weight of the second aspartic acid ester resin does not exceed 100% of the weight of the first aspartic acid ester resin.

9. The modified aspartame polyurea coating composition according to claim 1, characterized in that: The auxiliary agent comprises a dispersant, and the acid value of the dispersant is 5-140 mgKOH / g.

10. The modified aspartame polyurea coating composition according to claim 1, characterized in that: The equivalent ratio of the NH groups in the A component to the NCO groups in the B component is 1:0.8-1.2.

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