A branched polyurea urethane and a method for its preparation, a coating

Abstract

The application provides a branched polyurea urethane and a preparation method and a coating thereof. The branched polyurea urethane comprises a structure shown in formula I: wherein Y is selected from p-benzene or m-benzene, R1, R2, R3, R4, R5, R6 and R7 are independently selected from substituted or unsubstituted alkyl or substituted or unsubstituted aryl; and n, m and z are independently integers from 5 to 50. The polyurea urethane provided by the application contains a large number of amide bonds and urea bonds, contains a large number of intermolecular hydrogen bonds, and has the characteristics of high crosslinking degree, and thus has good temperature resistance and mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of polymer chemistry technology, specifically relating to a branched polyurethane, its preparation method, and a coating. Background Technology

[0002] Polyurea is obtained by reacting isocyanate-terminated prepolymers with amino-terminated resins and chain extenders. Due to the large number of hydrogen bonds and a certain degree of crosslinking in polyurea, it possesses excellent tensile strength, impact resistance, abrasion resistance, and corrosion resistance, and is widely used in coatings, elastomers, foams, adhesives, and other fields.

[0003] Because polyurea materials react rapidly, they tend to form excessively large molecular weights, which leads to poor flowability and consequently affects their processability. Current technologies typically improve the flowability of polyurea materials by reducing their molecular weight, thereby enhancing their processability. However, this method can reduce the mechanical properties of the polyurea to some extent.

[0004] Therefore, in order to balance the processability and mechanical properties of polyurea materials, it is necessary to study novel, low-viscosity polyurea amine components, which is of great significance to the development of polyurea materials. Summary of the Invention

[0005] To solve all or part of the above-mentioned technical problems, the main objective of this invention is to provide a branched polyurea urethane and its preparation method. The branched polyamide raw material of the branched polyurea urethane contains a large number of terminal amino groups, which can improve the branching degree and crosslinking degree of polyurea. The large number of intermolecular hydrogen bonds gives the polyurea good mechanical properties and temperature resistance. At the same time, the branched polyamide has the advantage of low viscosity, making it easier to mix evenly with isocyanate and improve the processability of polyurea.

[0006] A first aspect of the present invention is to provide a branched polyurethane, said branched polyurethane comprising the structure shown in Formula I:

[0007]

[0008] Wherein, Y is selected from p-benzene or m-benzene, R1, R2, R3, R4, R5, R6, and R7 are independently selected from substituted or unsubstituted alkyl groups or substituted or unsubstituted aryl groups; n, m, and z are independently integers between 5 and 50.

[0009] The "alkyl" mentioned above can be a straight-chain alkyl, a branched alkyl, or a cycloalkyl.

[0010] In some embodiments, R1 and R2 are selected from C1 to C2. 10 The substituted or unsubstituted alkyl or substituted or unsubstituted aryl groups.

[0011] In some preferred embodiments, R1 and R2 are selected from benzene rings, ethyl, propyl, isopropyl, or sec-butyl. These groups can be bio-based and have advantages such as good biocompatibility and low toxicity.

[0012] In some embodiments, R3 is selected from C2 to C3. 10 The substituted or unsubstituted alkyl or substituted or unsubstituted aryl groups.

[0013] In some preferred embodiments, R3 is selected from ethyl, propyl, pentyl, hexyl, decyl, phenyl, or benzyl.

[0014] In some embodiments, R4 and R5 are independently selected from C3 to C5. 10 The substituted or unsubstituted alkyl or substituted or unsubstituted aryl groups.

[0015] In some preferred embodiments, R4 and R5 are independently selected from phenyl, naphthyl, benzyl, butyl, hexyl, decyl, or groups represented by Formula II.

[0016]

[0017] The properties of polyurethane can be adjusted by modifying the R4 and R5 structures; more flexible chains result in better flexibility.

[0018] In some embodiments, R6 is selected from C2 to C3. 10 The substituted or unsubstituted alkyl or substituted or unsubstituted aryl groups.

[0019] In some preferred embodiments, R6 is selected from cyclohexyl, ethyl hexanoate, cyclohexanedimethyl, hexyl, naphthyl, phenyl, 1,1,3,3 tetramethylcyclohexyl, or trimethylhexamethylene.

[0020] In some embodiments, R7 is selected from C2 to C3. 10 The substituted or unsubstituted alkyl or substituted or unsubstituted aryl groups.

[0021] In some preferred embodiments, R7 is selected from ethyl, butyl, diethylphenyl, 3,3-dichlorotolyl, sodium 2-sulfonate-butyl, propyl, cyclohexyl, sec-butyl, or phenyl.

[0022] A second aspect of the present invention is to provide a branched polyurea-urethane, wherein the raw materials of the branched polyurea-urethane include component A and component B, wherein component A includes an amino-terminated branched polyamide resin and a chain extender, and component B includes an isocyanate compound; the amino-terminated branched polyamide resin includes a compound of formula III:

[0023]

[0024] Wherein, Y is selected from p-phenylene or m-phenylene, and R1, R2, R3, R4, R s The terms n, m, and z are independently selected from substituted or unsubstituted alkyl groups or substituted or unsubstituted aryl groups, and n, m, and z are independently integers between 5 and 50.

[0025] The branched polyamide resin shown in Formula III contains amide bonds, which can improve the thermal properties and processability of polyurea-urethane. Furthermore, this branched polyamide resin also has a three-dimensional structure as shown in the figure below. Its abundant terminal amino groups can react with isocyanates to form crosslinks, improving the mechanical properties of polyurea. Simultaneously, due to its three-dimensional structure, this polyamide resin has a lower viscosity than linear polyamide resins, improving its processing performance during polyurea preparation.

[0026]

[0027] In some embodiments, R1 and R2 are selected from C1 to C2. 10 The substituted or unsubstituted alkyl or substituted or unsubstituted aryl groups.

[0028] In some preferred embodiments, R1 and R2 are selected from benzene ring, ethyl, propyl, isopropyl, or sec-butyl.

[0029] In some embodiments, R3 is selected from C2 to C3. 10 The substituted or unsubstituted alkyl or substituted or unsubstituted aryl groups.

[0030] In some preferred embodiments, R3 is selected from ethyl, propyl, pentyl, hexyl, decyl, phenyl, or benzyl;

[0031] In some embodiments, R4 and R5 are independently selected from C3 to C5. 10 The substituted or unsubstituted alkyl or aryl groups.

[0032] In some preferred embodiments, R4 and R5 are independently selected from phenyl, naphthyl, benzyl, butyl, hexyl, decyl, or groups represented by Formula II.

[0033]

[0034] In some embodiments, the isocyanate compounds include one or more of the following: lysine diisocyanate, cyclohexane diisocyanate, cyclohexane dimethylene diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, naphthalene diisocyanate, terephthalic diisocyanate, and isophorone diisocyanate.

[0035] In some embodiments, the chain extender is a polyol and / or a polyamine. For example, it can be a small molecule polyol or polyamine with a molecular weight between tens and hundreds.

[0036] In some preferred embodiments, the chain extender includes one or more of the following: ethylene glycol, hydroquinone dihydroxyethyl ether, 1,4-butanediol, diethyltoluenediamine, 3,3′-dichloro-4,4′-diaminophenylmethane, sodium 1,4-butanediol-2-sulfonate, dimethylolpropionic acid, pentanediol, propylene glycol, neopentanediol, p-phenylenediamine, hexamethylenediamine, and m-phenylenediamine. When the chain extender is an amine chain extender, R7 is linked to the main chain via a urea bond; when the chain extender is an alcohol chain extender, R7 is linked to the main chain via a carbamate bond.

[0037] In some embodiments, components A and B further include solvents that do not contain active hydrogen.

[0038] In some preferred embodiments, the solvent includes one or a combination of more of benzene, toluene, xylene, ethyl acetate, and butyl acetate.

[0039] In some embodiments, the molar ratio of the sum of amino and / or hydroxyl groups in component A to the -NCO in component B is 1:1 to 1:1.5. When the isocyanate content is high, the isocyanate will continue to react with the -NH- in the polyurea upon heating, achieving further crosslinking, thereby further improving the mechanical properties and temperature resistance of the polyamide polyurea.

[0040] In some embodiments, in component A, the molar ratio of the terminal amino-branched polyamide resin to the amino and / or hydroxyl groups in the chain extender is 7:3 to 4:6.

[0041] The amino-terminated branched polyamide resin of Formula III described in this invention can be obtained, for example, by the following preparation method:

[0042] The preparation method includes: first heating a mixed reaction system containing a polybasic acid, a diamine, and a catalyst to 80–130°C for reaction, and then heating to 150–180°C for further reaction to obtain the terminal amino-branched polyamide resin, wherein the polybasic acid includes a tetrabasic acid represented by Formula IV.

[0043]

[0044] In Formula IV, Y, R1, and R2 are the same as those in Formula III. R3 in Formula III is derived from the diamine in the mixed reaction system, and R4 and R5 are derived from the tetracarboxylic acid in Formula IV and / or other polycarboxylic acids that may exist in the mixed reaction system.

[0045] The tetrabasic acid content is 5-100 wt% of the polybasic acid. The branching degree of the polyamide resin can be controlled by adjusting the tetrabasic acid content, thereby adjusting the solubility and amino content of the polyamide resin. Further, the tetrabasic acid content is 5-50 wt% of the polybasic acid. When the tetrabasic acid content is within this range, the obtained product has a certain degree of branching and contains abundant terminal and internal amino groups; simultaneously, the mechanical and thermal properties of the polyamide resin can be adjusted by adding other dibasic acids.

[0046] In the mixed reaction system for preparing the terminal amino-branched polyamide resin shown in Formula III, the amount of polybasic acid and diamine added makes the molar ratio of carboxyl groups to amino groups in the mixed reaction system 1:1.1 to 1:2, and further 1:1.1 to 1:1.5.

[0047] In the mixed reaction system for preparing the amino-terminated branched polyamide resin shown in Formula III, the polybasic acid may further include aliphatic diacids and / or aromatic diacids, accounting for 0% to 95% of the total polybasic acid content. Aliphatic diacids, for example, include those with C4 to C5 carbon atoms. 10 Aliphatic diacids.

[0048] For example, polybasic acids also include at least one of terephthalic acid, isophthalic acid, adipic acid, succinic acid, sebacic acid, and azelaic acid. They have advantages such as wide availability and low cost.

[0049] In the mixed reaction system for preparing the amino-terminated branched polyamide resin of Formula III, the diamine includes aliphatic diamines and / or aromatic diamines. The aliphatic diamine, for example, includes those with a carbon number of C2-C6. 18 Aliphatic diamines.

[0050] For example, diamines include at least one of m-phenylenediamine, p-phenylenediamine, m-phenylenediamine, ethylenediamine, diallyltriamine, propylenediamine, hexamethylenediamine, nonyldiamine, lauryldiamine, octadecanediamine, and decanediamine. They have advantages such as wide availability and low cost, and the properties of the curing agent can be adjusted by regulating the type of diacid and diamine.

[0051] In the mixed reaction system for preparing the amino-terminated branched polyamide resin shown in Formula III, the catalyst includes at least one of diphenylphosphine chloride, diethyl phosphate, dicyclohexylcarbodiimide, and triphenylphosphine. The catalyst content is 100–1000 ppm.

[0052] The preparation method of the amino-terminated branched polyamide resin of Formula III specifically includes: uniformly dispersing a polybasic acid, a diamine, and a catalyst in a solvent to obtain a mixed reaction system. The solvent may include, for example, at least one of water, dimethyl sulfoxide, dimethylformamide, and N-methylpyrrolidone.

[0053] The preparation method of the terminal amino-branched polyamide resin shown in Formula III specifically includes: first heating the mixed reaction system to 80-130℃ and maintaining it for 1-5 hours, and then heating it to 150-180℃ and maintaining it for 2-6 hours.

[0054] A third aspect of the present invention is to provide a method for preparing the branched polyurea urethane, the method comprising: uniformly mixing component A and component B, and reacting them at a temperature of room temperature to 150°C to obtain the branched polyurea urethane. Due to the high reactivity of amino groups, the branched polyurea urethane can be obtained by reacting at room temperature; of course, increasing the reaction temperature can increase the degree of intermolecular crosslinking and further improve the mechanical properties of the polyurea.

[0055] In some embodiments, the reaction time is 1 to 48 hours.

[0056] A fourth aspect of the present invention is to provide a coating comprising the branched polyurethane described in any of the technical solutions.

[0057] Compared with the prior art, the present invention has at least the following technical effects: The present invention uses the branched polyamide resin shown in Formula III as the raw material for synthesizing the above-mentioned polyurea urethane. The branched polyamide resin has a low viscosity and good compatibility with isocyanate, thereby improving the processing performance of polyurea; the branched polyamide resin has abundant terminal amino and amide bonds, thus enabling the synthesis of highly crosslinked polyurea; at the same time, the imide bonds contained in the branched polyamide resin can improve the thermal and mechanical properties of polyurea; and the polyamide resin can be based on bio-based sources, resulting in low biotoxicity; furthermore, the polyurea urethane provided by the present invention contains a large number of amide and urea bonds, has a high degree of crosslinking, and a large number of hydrogen bonds, which endow the polyurea urethane with good temperature resistance and mechanical properties, as well as good processability. Attached Figure Description

[0058] Figure 1 This is the DSC spectrum of the branched polyurea in Example 4 of the present invention. Detailed Implementation

[0059] The technical solutions of the present invention will be described in detail below with reference to specific embodiments, so that those skilled in the art can better understand and implement the technical solutions of the present invention. The specific functional details disclosed herein should not be construed as limiting, but are merely intended to form the basis of the claims and to teach those skilled in the art to employ the representative basis of the invention in different ways in any suitable detailed embodiment.

[0060] The raw materials and reagents used in the specific embodiments of this invention are all commercially available.

[0061] Example 1

[0062] (1) Preparation of component A:

[0063] 10g of terephthaloyl chloride was dissolved in 50g of dichloroethane and stirred to obtain a terephthaloyl chloride solution. 26.5g of 2-aminoterephthalic acid was weighed and dissolved in 100g of water. The pH was adjusted to 8.0 using sodium carbonate to obtain an aqueous solution of 2-aminoterephthalic acid. The terephthaloyl chloride solution was slowly added dropwise to the aqueous solution of 2-aminoterephthalic acid. During the reaction, the pH was controlled between 7.5 and 8.0, and the temperature was controlled at 10±5℃. The reaction yielded a tetrabasic acid monomer synthesized from terephthaloyl chloride and 2-aminoterephthalic acid.

[0064] Using 0.2 mol of the above-synthesized tetracarboxylic acid monomer, 0.6 mol of sebacic acid, and 1.2 mol of hexamethylenediamine under nitrogen protection, with dicyclohexylcarbodiimide as a catalyst, the reaction was carried out at 1.5 MPa and 150 °C for 2 h. Then, the mixture was slowly evacuated and heated to 200 °C for 1 h to obtain polyamide resin. After cooling, 0.2 mol of pentanediol and a small amount of toluene were added, and the viscosity was measured to be 68 mPa·s. The resin was then sealed and stored for later use.

[0065] (2) Preparation of component B:

[0066] Dissolve naphthalene diisocyanate in toluene, seal and store for later use.

[0067] (3) Preparation of branched polyurethane:

[0068] Weigh out 80g of component A and 20g of component B, mix them, and apply the mixture to a wooden board with a thickness of 200±10μm. Slowly dry the solvent and heat it to 150℃ for 1h to obtain a polyurethane coating.

[0069] The polyurea-urethane coating was tested according to GB / T 19250-2013 standard. Its tensile strength was 35.7 MPa; its impact resistance was 50 cm without cracks, wrinkles or peeling; and its melting point was 276℃.

[0070] Example 2

[0071] (1) Preparation of component A:

[0072] 10g of terephthaloyl chloride was dissolved in 50g of dichloroethane and stirred to obtain a terephthaloyl chloride solution. 26.5g of aminoglutaric acid was weighed and dissolved in 100g of water, and the pH was adjusted to 8.0 with sodium carbonate to obtain an aqueous solution of aminoglutaric acid. The terephthaloyl chloride solution was slowly added dropwise to the aminoglutaric acid aqueous solution. During the reaction, the pH was controlled between 7.5 and 8.0, and the temperature was controlled at 10±5℃. The reaction yielded a tetrabasic acid monomer synthesized from terephthaloyl chloride and aminoglutaric acid.

[0073] The tetracarboxylic acid monomer synthesized above, isophthalic acid, and isophthalic dimethylamine were mixed at a carboxyl to amino molar ratio of 1:1.5. Under nitrogen protection, triphenylphosphine was used as a catalyst, and the mixture was reacted at 1.8 MPa and 160 °C for 3 h. Then, the mixture was slowly evacuated and heated to 240 °C for 1 h to obtain polyamide resin. After cooling, 0.3 moles of hexanediol and a small amount of ethyl acetate were added, and the viscosity was measured to be 101 mPa·s. The resin was then sealed and stored for later use.

[0074] (2) Preparation of component B:

[0075] Dissolve cyclohexane diisocyanate in ethyl acetate, seal and store for later use.

[0076] (3) Preparation of branched polyurethane:

[0077] Weigh 25.1g of component A and 15.2g of component B, mix them, and coat them onto a stainless steel plate with a coating thickness of 200±10μm. Slowly dry the solvent and heat to 80℃ for 2h to obtain polyurethane.

[0078] Its tensile strength was tested to be 32.6 MPa; impact resistance: no cracks, wrinkles or peeling were observed after a 50 cm impact; melting point: 268℃.

[0079] Example 3

[0080] (1) Preparation of component A:

[0081] 10g of isophthaloyl chloride was dissolved in 50g of dichloroethane and stirred to obtain an isophthaloyl chloride solution. 26.5g of aminosuccinic acid was weighed and dissolved in 100g of water, and the pH was adjusted to 8.0 with sodium carbonate to obtain an aqueous solution of aminosuccinic acid. The isophthaloyl chloride solution was slowly added dropwise to the aminosuccinic acid aqueous solution. During the reaction, the pH was controlled between 7.5 and 8.0, and the temperature was controlled at 10±5℃. The reaction yielded a tetrabasic acid monomer synthesized from isophthaloyl chloride and aminosuccinic acid.

[0082] Using this tetracarboxylic acid monomer, oxalic acid, and propylenediamine, a carboxyl to amino molar ratio of 1:1.3 was mixed. Under nitrogen protection, diphenylphosphoyl chloride was used as a catalyst, and the mixture was reacted at 2.0 MPa and 130 °C for 3 h. Then, the mixture was slowly evacuated and heated to 220 °C for 2 h to obtain polyamide resin. After cooling, 0.1 molar amount of diethyltoluenediamine and a small amount of xylene were added, and the viscosity was measured to be 93 mPa·s. The resin was then sealed and stored for later use.

[0083] (2) Preparation of component B:

[0084] Dissolve lysine diisocyanate in xylene, seal and store for later use.

[0085] (3) Preparation of branched polyurethane:

[0086] Weigh 20.3g of component A and 8.9g of component B, mix them, and coat them onto an iron plate with a coating thickness of 200±10μm. Let the solvent evaporate slowly at room temperature and cure at room temperature for 48h to obtain branched polyurethane.

[0087] Its tensile strength was tested to be 31.2 MPa; impact resistance: no cracks, wrinkles or peeling were observed after a 50cm impact; melting point: 243℃.

[0088] Example 4

[0089] (1) Preparation of component A

[0090] 10g of isophthaloyl chloride was dissolved in 50g of dichloroethane and stirred to obtain an isophthaloyl chloride solution. 26.5g of 3-aminophthalic acid was weighed and dissolved in 100g of water. The pH was adjusted to 8.0 using sodium carbonate to obtain an aqueous solution of 3-aminophthalic acid. The isophthaloyl chloride solution was slowly added dropwise to the aqueous solution of 3-aminophthalic acid. During the reaction, the pH was controlled between 7.5 and 8.0, and the temperature was controlled at 10±5℃. The reaction yielded a tetrabasic acid monomer synthesized from isophthaloyl chloride and 3-aminophthalic acid.

[0091] Using this tetracarboxylic acid monomer, isophthalic acid, and decanediamine, a carboxyl to amino molar ratio of 1:1.3 was mixed and reacted under nitrogen protection with diphenylphosphochloride as a catalyst at 2.0 MPa and 130 °C for 3 h. Then, the mixture was slowly evacuated and heated to 220 °C for 2 h to obtain polyurethane. After cooling, 0.2 moles of m-phenylenediamine and a small amount of toluene were added, and the viscosity was measured to be 65 mPa·s. The mixture was then sealed and stored for later use.

[0092] (2) Preparation of component B:

[0093] Dissolve trimethyl-1,6-hexamethylene diisocyanate in toluene, seal and store for later use.

[0094] (3) Preparation of branched polyurethane:

[0095] Weigh 15.2g of component A and 8.1g of component B, mix them, and coat them onto stainless steel with a coating thickness of 200±10μm. Let the solvent evaporate slowly at room temperature and cure at room temperature for 48h to obtain polyurethane. Figure 1 The image shows the DSC spectrum of the branched polyurea in Example 4.

[0096] Its tensile strength was tested to be 28.3 MPa; impact resistance: no cracks, wrinkles or peeling were observed after a 50cm impact; melting point was 229℃.

[0097] Example 5

[0098] (1) Preparation of component A:

[0099] 10g of isophthaloyl chloride was dissolved in 50g of dichloroethane and stirred to obtain an isophthaloyl chloride solution. 26.5g of aminomalonic acid was weighed and dissolved in 100g of water, and the pH was adjusted to 8.0 with sodium carbonate to obtain an aminomalonic acid aqueous solution. The isophthaloyl chloride solution was slowly added dropwise to the aminomalonic acid aqueous solution. During the reaction, the pH was controlled between 7.5 and 8.0, and the temperature was controlled at 10±5℃. The reaction yielded a tetrabasic acid monomer synthesized from isophthaloyl chloride and aminomalonic acid.

[0100] Using this tetracarboxylic acid monomer, adipic acid, and ethylenediamine in a carboxyl to amino molar ratio of 1:1.3, under nitrogen protection, diphenylphosphochloride was used as a catalyst, and the reaction was carried out at 2.0 MPa and 130 °C for 3 h. Then, the mixture was slowly evacuated and heated to 220 °C for 2 h to obtain polyamide resin. After cooling, 0.1 molar amount of 1,4-butanediol-2-sulfonate sodium and a small amount of xylene were added. The viscosity was measured to be 93 mPa·s. The resin was then sealed and stored for later use.

[0101] (2) Preparation of component B:

[0102] Component B was prepared by dissolving terephthalic diisocyanate in toluene;

[0103] (3) Preparation of branched polyurethane:

[0104] Weigh 20.5g of component A and 6.8g of component B, mix them, and coat them onto an iron plate with a coating thickness of 200±10μm. Slowly dry the solvent and heat to 120℃ to cure for 2 hours to obtain branched polyurethane.

[0105] Its tensile strength was tested to be 33.2 MPa; impact resistance: no cracks, wrinkles or peeling were observed after a 50cm impact; melting point: 256℃.

[0106] Example 6

[0107] (1) Preparation of component A:

[0108] 10g of isophthaloyl chloride was dissolved in 50g of dichloroethane and stirred to obtain an isophthaloyl chloride solution. 26.5g of diaminododecanoic acid was weighed and dissolved in 100g of water, and the pH was adjusted to 8.0 with sodium carbonate to obtain an aqueous solution of diaminododecanoic acid. The isophthaloyl chloride solution was slowly added dropwise to the aqueous solution of diaminododecanoic acid. During the reaction, the pH was controlled between 7.5 and 8.0, and the temperature was controlled at 10±5℃. The reaction yielded a tetrabasic acid monomer synthesized from isophthaloyl chloride and diaminododecanoic acid.

[0109] Using this tetracarboxylic acid monomer, terephthalic acid, and butanediamine, a carboxyl to amino molar ratio of 1:1.3 was mixed. Under nitrogen protection, diphenylphosphoyl chloride was used as a catalyst, and the mixture was reacted at 2.0 MPa and 130 °C for 3 h. Then, the mixture was slowly evacuated and heated to 220 °C for 2 h to obtain a polyamide resin. After cooling, 0.1 molar amount of 3,3′-dichloro-4,4′-diaminophenylmethane and a small amount of xylene were added. The viscosity was measured to be 93 mPa·s. The resin was then sealed and stored for later use.

[0110] (2) Preparation of component B:

[0111] Isophorone diisocyanate was dissolved in toluene to prepare component B.

[0112] (3) Preparation of branched polyurethane:

[0113] Weigh 20.5g of component A and 6.8g of component B, mix them, and coat them onto an iron plate with a coating thickness of 200±10μm. Slowly dry the solvent and heat to 130℃ to cure for 1.5h to obtain branched polyurethane.

[0114] Its tensile strength was tested to be 32.9 MPa; impact resistance: no cracks, wrinkles or peeling were observed after a 50cm impact; melting point: 248℃.

[0115] Comparative Example 1

[0116] The only difference between Comparative Example 1 and Example 3 is that the tetracarboxylic acid monomer used in the preparation of component A is terephthalic acid, as detailed below:

[0117] Terephthalic acid and decanediamine were mixed in a molar ratio of 1:1.3 and reacted under nitrogen protection with diphenylphosphine chloride as a catalyst at 2.0 MPa and 130 °C for 3 h. Then, the mixture was slowly evacuated and heated to 220 °C for 2 h to obtain polyurethane. After cooling, 0.2 moles of m-phenylenediamine and a small amount of toluene were added, and the viscosity was measured to be 378 mPa·s. The mixture was then sealed and stored for later use.

[0118] The branched polyurea-urethane coating was prepared in the same manner as in Example 3. Its tensile strength was tested to be 21.3 MPa; impact resistance: no cracks, wrinkles, or peeling were observed after a 50 cm impact; melting point was 206°C.

[0119] Table 1. Relevant properties of component A and branched polyurethane coatings in the embodiments and comparative examples of the present invention.

[0120]

[0121]

[0122] In summary, the polyurea urethane prepared by this invention has better strength, mainly because component A in the preparation of this invention is a branched polyamide polyester with more terminal amino groups. Therefore, the prepared polyurea has a higher degree of crosslinking. At the same time, the presence of a small amount of imide bonds improves the temperature resistance of the polyurea urethane.

[0123] All aspects, embodiments, features, and examples of this invention are to be regarded as illustrative in all respects and are not intended to limit the invention, the scope of which is defined only by the claims. Other embodiments, modifications, and uses will become apparent to those skilled in the art without departing from the spirit and scope of the invention as claimed.

[0124] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0125] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this invention is not intended to be limited to the specific embodiments disclosed for carrying out the invention, but rather is intended to encompass all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated otherwise, any use of the terms first, second, etc., does not indicate any order or importance, but is used to distinguish one element from another.

Claims

1. A branched polyurethane, characterized in that, The method for preparing the branched polyurea urethane includes: uniformly mixing component A and component B, and reacting them at a temperature of room temperature to 150°C to obtain the branched polyurea urethane; component A includes terminal amino-branched polyamide resin and chain extender, and component B includes isocyanate compounds; and the molar ratio of the terminal amino-branched polyamide resin in component A to the hydroxyl groups in the chain extender, or the sum of hydroxyl and amino groups, is 7:3 to 4:6, and the molar ratio of the sum of amino and hydroxyl groups in component A to the -NCO group in component B is 1:1 to 1:1.5; The method for preparing the terminal amino-branched polyamide resin includes: first heating a mixed reaction system containing a polybasic acid, a diamine, and a catalyst to 80-130°C for reaction, and then heating to 150-180°C for reaction to obtain the terminal amino-branched polyamide resin; wherein, the polybasic acid includes a tetrabasic acid as shown in Formula IV and other aliphatic diacids and / or aromatic diacids, and the content of the tetrabasic acid is 5-50 wt% of the polybasic acid; the diamine includes aliphatic diamines and / or aromatic diamines; the amount of polybasic acid and diamine added is such that the molar ratio of carboxyl groups to amino groups in the mixed reaction system is 1:1.1 to 1:2; ; In Formula IV, Y is selected from p-benzene or m-benzene, and R1 and R2 are independently selected from substituted or unsubstituted alkyl or substituted or unsubstituted aryl groups; The chain extender is selected from one or more of the following: ethylene glycol, hydroquinone dihydroxyethyl ether, 1,4-butanediol, diethyltoluenediamine, 3,3'-dichloro-4,4'-diaminophenylmethane, sodium 1,4-butanediol-2-sulfonate, dimethylolpropionic acid, pentanediol, propylene glycol, neopentanediol, p-phenylenediamine, hexamethylenediamine, and m-phenylenediamine.

2. The branched polyurea urethane according to claim 1, characterized in that: R1 and R2 are selected from C1~C2. 10 The substituted or unsubstituted alkyl or substituted or unsubstituted aryl groups.

3. The branched polyurethane according to claim 2, characterized in that: R1 and R2 are selected from benzene ring, ethyl, propyl, isopropyl, or sec-butyl.

4. The branched polyurea urethane according to claim 1, characterized in that: The isocyanate compounds include one or more of the following: lysine diisocyanate, cyclohexane diisocyanate, cyclohexane dimethylene diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, naphthalene diisocyanate, terephthalic diisocyanate, and isophorone diisocyanate.

5. The branched polyurea urethane according to claim 1, characterized in that: Components A and B also include solvents that do not contain active hydrogen.

6. The branched polyurea urethane according to claim 5, characterized in that: The solvent includes one or a combination of more of the following: benzene, toluene, xylene, ethyl acetate, and butyl acetate.

7. The branched polyurea urethane according to claim 1, characterized in that: Components A and B are uniformly mixed and reacted at room temperature to 150°C for 1 to 48 hours to obtain the branched polyurethane.

8. A coating, characterized in that, The coating comprises the branched polyurethane according to any one of claims 1 to 7.

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