A 4-position linked naphthalene diisocyanate, a method for synthesizing the same and use thereof in preparing a naphthalene polyurethane material

Abstract

The application discloses a 4-position linked naphthalene diisocyanate which is a halogenated acyl naphthylamine, is prepared by an Ullmann coupling reaction in the presence of a ligand and under the protection of an inert gas with a metal or a salt thereof as a catalyst, amide hydrolysis, and then carbonation with a carbonation reagent. Based on the same inventive concept, the application further discloses a preparation method of the 4-position linked naphthalene diisocyanate. Based on the same inventive concept, the application further discloses applications of the 4-position linked naphthalene diisocyanate in preparation of urethane rubber and elastomer, urethane fiber, cast urethane rubber, urethane emulsion and paint, urethane adhesive and urethane foam material. The obtained linked naphthalene polyurethane has better wear resistance and impact resistance modulus than common polyurethane materials, and can be used for preparing high-impact urethane devices and high-foaming-rate damping shock-absorbing energy-absorbing foam materials.

Description

Technical Field

[0001] This invention belongs to the field of urethane material preparation technology, specifically relating to a 4-position naphthalene diisocyanate, its synthesis method, and its application in the preparation of naphthalene polyurethane materials. Background Technology

[0002] Polyurethane, abbreviated as PU, is a class of polymer materials containing a large number of repeating urethane groups (-NHCOO-) in its molecular chain. Polyurethane elastomers are a relatively unique class of elastomers. From a molecular structure perspective, polyurethane elastomers are block polymers, generally consisting of soft segments formed by flexible long chains of oligomeric polyols, and hard segments formed by diisocyanates and chain extenders. The hard and soft segments are arranged alternately to form repeating structural units. In addition to containing urethane groups, hydrogen bonds can form within and between polyurethane molecules, and the soft and hard segments can form microphase regions, resulting in microphase separation.

[0003] The symmetry and rigidity of the 1,5-naphthalene diisocyanate (NDI) molecular structure give polyurethane elastomers, which use 1,5-naphthalene diisocyanate as a synthetic intermediate, high hardness, good wear resistance, strong impact resistance, good stability, and high temperature resistance. NDI is one of the hard segment raw materials required to manufacture high-elasticity and high-hardness polyurethane elastomers, and polyurethane elastomers using NDI as a synthetic intermediate are among the isocyanate monomers available on the market. However, in some special applications under high temperature and high heat environments, materials need to have stronger dynamic properties and higher fatigue resistance, so that the materials have both excellent mechanical properties and heat resistance. Isocyanate monomers that can meet such demanding conditions are very rare. Summary of the Invention

[0004] The purpose of this invention is to address the problems of existing technologies by providing a 4-position naphthalene diisocyanate, its synthesis method, and its application in the preparation of naphthalene polyurethane materials. The 4-position naphthalene diisocyanate provided by this invention, as a high-modulus organic synthesis intermediate, possesses stable chemical bonds and a dense molecular structure. Polynaphthalene polyurethane prepared using the 4-position naphthalene diisocyanate of this invention exhibits better wear resistance and impact modulus than ordinary polyurethane materials. It can be used to prepare high-impact-resistant polyurethane devices and high-expansion-rate damping, shock-absorbing, and energy-absorbing foam materials.

[0005] The technical solution of this invention is implemented as follows:

[0006] A 4-position naphthalene diisocyanate, which is a haloacrylnaphthaleneamine, is prepared by a Ullmann coupling reaction in the presence of a ligand and under inert gas protection, using a metal or its salt as a catalyst, followed by amide hydrolysis and then carbonylation with a carbonylating agent. Preferably, the metal or its salt mentioned in this invention is a metal or its salt such as nickel, copper, palladium, or platinum.

[0007] As described above, a 4-position naphthalene diisocyanate, wherein the haloacylnaphthylamine has the structure shown in formula (I), wherein X is chlorine, bromine, iodine, trifluoromethanesulfonyloxy or p-toluenesulfonyloxy; R1 is C1-C1. 10 Straight-chain or branched alkyl groups, C1-C 10 alkoxy or C1-C 10 alkylthio group.

[0008]

[0009] The structure of the product generated by the Ullman coupling reaction of the above-mentioned 4-position naphthalene diisocyanate is shown in formula (II), wherein R1 is C1 to C2. 10 Straight-chain or branched alkyl groups, C1-C 10 alkoxy or C1-C 10 alkylthio group,

[0010]

[0011] The structure of the product generated by the amide hydrolysis reaction of the aforementioned 4-position naphthalene diisocyanate is shown in formula (III).

[0012]

[0013] The structure of the product generated by the carbonylation reaction of the 4-position naphthalene diisocyanate described above is shown in formula (Ⅳ).

[0014]

[0015] The 4-position naphthalene diisocyanate provided by this invention is an important organic synthesis intermediate used to manufacture polyurethane elastomers with high elasticity and high hardness. The resulting urethane is suitable for extreme environments requiring high strength, high hardness, wear resistance, and high temperature resistance, such as those in new energy vehicle batteries, shock absorbers, bridges, and military applications. The 4-position naphthalene diisocyanate provided by this invention possesses stable chemical bonds and a dense molecular structure, thus exhibiting excellent thermal stability and tensile strength. The resulting polynaphthalene urethane has high cohesive energy and impact modulus, making it particularly suitable for applications requiring high wear resistance and high heat resistance. As a polymer material with excellent properties and wide applications, the synthesis method and technological applications of this polynaphthalene urethane are of significant value.

[0016] Based on the same inventive concept, the present invention also provides a method for synthesizing 4-position naphthalene diisocyanate, comprising the following steps:

[0017] Step 1: Halogenated acyl naphthylamine is dissolved in an organic solvent and reacted with a metal or its salt as a catalyst in the presence of a ligand under inert gas protection at a temperature of 100–150 °C for 24–48 h. After the reaction mixture is cooled, the solvent is evaporated by filtration. The product is purified by column chromatography using ethyl acetate and n-heptane in a volume ratio of 1:4 as eluent to obtain a yellow solid product, namely alkyl acyl naphthylamine.

[0018] Optionally, the organic solvent in step one is either anhydrous N,N-dimethylformamide (hereinafter referred to as "DMF") or anhydrous tetrahydrofuran. Preferably, the organic solvent is anhydrous DMF.

[0019] Optionally, the catalyst is any one of cuprous iodide, cuprous oxide, and nickel chloride. Preferably, the catalyst is cuprous iodide.

[0020] Optionally, the ligand in step one is any one of N,N-dimethylethylenediamine, 1,2-cyclohexanediamine, and triphenylphosphine. Preferably, the ligand is N,N-dimethylethylenediamine.

[0021] Preferably, step one is performed under alkaline conditions, wherein the alkalinity is adjusted using an inorganic base; optionally, the inorganic base is cesium carbonate. Optionally, the molar ratio of the haloacrylnaphthylamine to the inorganic base is 1:(1-3). Preferably, the molar ratio of the haloacrylnaphthylamine to the inorganic base is 1:2.

[0022] Optionally, the molar ratio of the haloacrylnaphthylamine to the catalyst is (8-12):1. Preferably, the molar ratio of the haloacrylnaphthylamine to the catalyst is 10:1.

[0023] Optionally, the molar ratio of the haloacrylnaphthylamine to the ligand is (8-12):9. Preferably, the molar ratio of the haloacrylnaphthylamine to the ligand is 10:9.

[0024] Step 2: The alkyl acyl-binaphthylamine from Step 1 is subjected to a hydrolysis reaction under acidic conditions and heated under reflux to generate binaphthyldiamine.

[0025] Optionally, the obtained alkyl acyl naphthylamine is added to a mixed solution of 36% concentrated hydrochloric acid and ethanol, heated to 85-95°C and refluxed for 2-4 hours, cooled, filtered, and dried to obtain a yellow solid product, namely naphthyldiamine;

[0026] Step 3: The binaphthyl diamine from step 2 undergoes a carbonylation reaction with a carbonylating reagent to generate binaphthyl diisocyanate.

[0027] Optionally, the carbonylating agent is phosgene or triphosgene, etc. Preferably, the carbonylating agent is a solution of triphosgene dissolved in 1,2-dichlorobenzene. Specifically, dry binaphthyldiamine is dissolved in 1,2-dichlorobenzene solvent and stirred and heated to 120°C. The 1,2-dichlorobenzene solution of triphosgene is slowly added dropwise to the binaphthyldiamine over a period of 48 hours. After the addition is complete, the mixture is heated under reflux for 3–6 hours until the reaction system is clear and transparent. The organic solvent is removed by separation to obtain crude terephthalic diisocyanate. The crude product is further recrystallized in xylene to obtain a yellow solid product, namely binaphthyl diisocyanate at position 4. The reaction formula is shown below.

[0028]

[0029] Optionally, the mass ratio of the binaphthyldiamine to the carbonylating agent is (4-5):(8-9). Most preferably, the mass ratio of the binaphthyldiamine to the carbonylating agent is 4.53:8.

[0030] Based on the same inventive concept, the present invention also provides the application of a 4-position naphthalene diisocyanate as described above or a 4-position naphthalene diisocyanate synthesized by the synthesis method described above in the preparation of urethane rubber and elastomers, urethane fibers, cast urethane rubber, urethane emulsions and coatings, urethane adhesives and urethane foam materials.

[0031] Based on the same inventive concept, the present invention also provides a carbamate material, which is prepared by using a 4-position naphthalene diisocyanate as described above or a 4-position naphthalene diisocyanate synthesized by the synthesis method described above.

[0032] Compared with the prior art, the advantages of this invention are:

[0033] 1. The 4-position naphthalene diisocyanate provided by this invention has a four-ring structure with high covalent bond stability, exhibiting excellent chemical and thermal stability. Furthermore, the naphthalene rings are connected by C-C bonds, resulting in a very strong rigidity in its molecular structure. This rigidity gives the polymer outstanding mechanical strength, and the material possesses advantages such as high hardness, good elasticity, and excellent mechanical properties.

[0034] 2. The 4-position naphthalene diisocyanate provided by the present invention has a large conjugated structure and stable chemical bonds. The prepared naphthalene polyurethane has a very high thermal decomposition temperature, reaching 317℃, and excellent heat resistance. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0036] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0037] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0038] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0039] In the following examples, the 1-acetamido-4-bromonaphthalene was purchased from Shanghai Bide Pharmaceutical Technology Co., Ltd., with CAS number 91394-66-0 and a density of 1.528 g / cm³. 3 , molecular weight 264.1.

[0040] Example 1:

[0041] This embodiment provides a 4-position binaphthyl diisocyanate, the synthesis method of which includes the following specific steps:

[0042] Step 1: Weigh 10.56 g of 1-acetamido-4-bromonaphthalene and dissolve it in 50 mL of anhydrous DMF. Stir to dissolve, add 0.8 g of cuprous iodide, 4 mL of N,N-dimethylethylenediamine, and 26 g of cesium carbonate. Under nitrogen protection, slowly heat to 120 °C and react for 24 h. After the reaction is complete, cool and filter to evaporate the solvent. Use ethyl acetate and n-heptane in a volume ratio of 1:4 as eluent for column chromatography to obtain 6.12 g of yellow solid product (i.e., alkyl alkyl naphthylamine), with a yield of 83%.

[0043] Step 2: Add 6.12 g of the alkyl acyl naphthylamine obtained in Step 1 to a mixed solution of 50 mL of 36% concentrated hydrochloric acid and 50 mL of ethanol, heat to 75 °C, reflux for 3 h, cool, filter, and dry to obtain 4.53 g of yellow solid product (i.e., naphthyldiamine), with a yield of 96%.

[0044] Step 3: Dissolve 4.53 g of dried biphenyl diamine in 20 mL of 1,2-dichlorobenzene, stir and heat to 120 °C. Slowly add 40 g of a triphosgene 1,2-dichlorobenzene solution (mass concentration of triphosgene 1,2-dichlorobenzene solution is 20%) to the biphenyl diamine solution over a period of 48 h. After the addition is complete, continue heating under reflux for 4 h until the reaction system is clear and transparent. Remove the organic solvent by separation to obtain crude terephthalic diisocyanate. Recrystallize the crude product in xylene to obtain 4.93 g of a yellow solid product, namely biphenyl diisocyanate at position 4, with a yield of 92%.

[0045] The product identification results are as follows:

[0046] GC-MS: 336.09;

[0047] NMR measurements: 1H NMR (400MHz, DMSO-d6) δ: 8.92 (d, 2H, Ar-H), 8.52 (d, 2H, Ar-H), 7.83 (d, 2H, Ar-H), 7.52 (p, 6H, Ar-H).

[0048] 13C NMR (101MHz, DMSO-d6) δ: 134.2(2C), 132.2(2C), 131.2(2C), 128.4(2C), 128.3(4C), 127.7(2C, NCO), 126.3(4C), 119.2(2C), 118.5(2C).

[0049] Example 2:

[0050] This embodiment provides a 4-position binaphthyl diisocyanate, the synthesis method of which includes the following specific steps:

[0051] Step 1: Weigh 10.56 g of 1-acetamido-4-bromonaphthalene and dissolve it in 50 mL of anhydrous tetrahydrofuran. Stir to dissolve, add 0.57 g of cuprous oxide, 4.9 mL of 1,2-cyclohexanediamine, and 26 g of cesium carbonate. Under nitrogen protection, slowly heat to 120 °C and react for 24 h. After the reaction is complete, cool and filter to evaporate the solvent. Use ethyl acetate and n-heptane in a volume ratio of 1:4 as eluent for column chromatography purification to obtain 5.97 g of yellow solid product (i.e., alkyl alkyl naphthylamine), with a yield of 81%.

[0052] Step 2: Add 5.97 g of the alkyl acyl naphthylamine obtained in Step 1 to a mixed solution of 50 mL of 36% concentrated hydrochloric acid and 50 mL of ethanol, heat to 75 °C, reflux for 2 h, cool, filter, and dry to obtain 4.47 g of yellow solid product (i.e., naphthyldiamine), with a yield of 97%.

[0053] Step 3: Dissolve 4.47 g of dried biphenyl diamine in 20 mL of 1,2-dichlorobenzene, stir and heat to 120 °C. Slowly add 45 g of a triphosgene 1,2-dichlorobenzene solution (mass concentration of triphosgene 1,2-dichlorobenzene solution was 20%) to the biphenyl diamine solution over a period of 48 h. After the addition is complete, continue heating under reflux for 4 h until the reaction system is clear and transparent. Remove the organic solvent by separation to obtain crude terephthalic diisocyanate. Recrystallize the crude product in xylene to obtain 4.91 g of a yellow solid product, namely biphenyl diisocyanate at position 4, with a yield of 93%.

[0054] The product identification results are as follows:

[0055] GC-MS: 336.09;

[0056] NMR measurements: 1H NMR (400MHz, DMSO-d6) δ: 8.92 (d, 2H, Ar-H), 8.52 (d, 2H, Ar-H), 7.83 (d, 2H, Ar-H), 7.52 (p, 6H, Ar-H).

[0057] 13C NMR (101MHz, DMSO-d6) δ: 134.2(2C), 132.2(2C), 131.2(2C), 128.4(2C), 128.3(4C), 127.7(2C, NCO), 126.3(4C), 119.2(2C), 118.5(2C).

[0058] Example 3:

[0059] This embodiment provides a 4-position binaphthyl diisocyanate, the synthesis method of which includes the following specific steps:

[0060] Step 1: Dissolve 10.56 g of 1-acetamido-4-bromonaphthalene in 50 mL of anhydrous DMF with stirring. Add 0.52 g of nickel chloride and 10.5 g of triphenylphosphine. Under nitrogen protection, slowly heat to 120 °C and react for 24 h. After the reaction is complete, cool and filter to evaporate the solvent. Use ethyl acetate and n-heptane in a volume ratio of 1:4 as eluent for column chromatography to obtain 5.82 g of yellow solid product (i.e., alkyl alkyl naphthylamine), with a yield of 79%.

[0061] Step 2: Add 5.82 g of the alkyl acyl naphthylamine obtained in Step 1 to a mixed solution of 50 mL of 36% concentrated hydrochloric acid and 50 mL of ethanol, heat to 75 °C, reflux for 3 h, cool, filter, and dry to obtain 4.22 g of yellow solid product (i.e., naphthyldiamine), with a yield of 94%.

[0062] Step 3: Dissolve 4.22 g of dried biphenyl diamine in 20 mL of 1,2-dichlorobenzene and heat to 120 °C with stirring. Slowly add 40 g of a triphosgene solution in 1,2-dichlorobenzene (with a mass concentration of 20%) to the biphenyl diamine solution. The addition time is 48 h. After the addition is complete, continue heating under reflux for 4 h until the reaction system is clear and transparent. Remove the organic solvent by separation to obtain crude terephthalic diisocyanate. Recrystallize the crude product in xylene to obtain 4.49 g of a yellow solid product, namely biphenyl diisocyanate at position 4, with a yield of 90%.

[0063] The product identification results are as follows:

[0064] GC-MS: 336.09;

[0065] NMR measurements: 1H NMR (400MHz, DMSO-d6) δ: 8.92 (d, 2H, Ar-H), 8.52 (d, 2H, Ar-H), 7.83 (d, 2H, Ar-H), 7.52 (p, 6H, Ar-H).

[0066] 13C NMR (101MHz, DMSO-d6) δ: 134.2(2C), 132.2(2C), 131.2(2C), 128.4(2C), 128.3(4C), 127.7(2C, NCO), 126.3(4C), 119.2(2C), 118.5(2C).

[0067] Comparative Example 1:

[0068] 1,5-Naphthalene diisocyanate (hereinafter referred to as NDI) was purchased from Qingdao Dexin Chemical Co., Ltd., CAS No.: 3173-72-6.

[0069] The present invention uses the 4-position naphthalene diisocyanate described in Example 1 and the polyurethane prepared by prepolymerization of NDI in Comparative Example 1 for performance testing.

[0070] In Example 1, the NCO (isocyanate group) content of the 4-position naphthalene diisocyanate was 21.8%; in Comparative Example 1, the NDI had an NCO (isocyanate group) content of 40.0%. The polyether triol was purchased from Dow Chemical Company, VORANOL 4701, with a molecular weight of 5000, a hydroxyl value of 34 mgKOH / g, and a moisture content ≤0.04%. The blowing agent HFC-245FA was purchased from Wuhan Jiangxinyu Biotechnology Co., Ltd., and the surfactant OFX-0193 was purchased from Dow Corning.

[0071] Application Example 1:

[0072] A method for preparing binaphthyl polyurethane via prepolymerization includes the following steps:

[0073] (1) An excess of the 4-position naphthalene diisocyanate from Example 1 was reacted with polyether triol at 95°C to form a prepolymer with a terminal -NCO group content of 9%.

[0074] (2) Casting: The prepolymer and chain extender components in step (1) are mixed at a mass ratio of 100:12.5. The mixing speed is 1800 r / min and the mixture is stirred for 30 s. The reaction liquid is then poured into a mold at a temperature of 90°C. After pre-curing, the mixture is demolded. The chain extender components include the following components in parts by weight: 59 parts of chain extender 1,7-heptadecyl glycol, 32 parts of catalyst dimethylcyclohexylamine, 4 parts of foaming agent HFC-245FA, and 5 parts of surfactant OFX-0193.

[0075] (3) Post-curing: The demolded product is cured in an oven at 105℃ for 12 hours and left at room temperature for 5 days to obtain naphthalene polyurethane.

[0076] Application Example 2:

[0077] The difference from Application Example 1 is that the 4-position naphthalene diisocyanate in Example 1 is replaced with NDI in Comparative Example 1.

[0078] The polyurethanes prepared by the prepolymerization method in Application Examples 1 and 2 were tested, and their properties are shown in Table 1.

[0079] Table 1. Test results of polyurethane produced by the prepolymerization process.

[0080] Testing items unit Experimental methods Application Example 1 Application Example 2 density g / cm3 GB / T 1033.1-2008 1.01 1.02 Tensile strength MPa GB / T 1040-2006 3.7 2.9 elongation ％ GB / T 528-2009 367 278 Shaw Brothers A HA GB / T 2411-2008 72 65 Tear strength kN / m GB / T 10808-2006 3.9 3.1 Decomposition temperature ℃ TGA 317℃ 262℃

[0081] As shown in Table 1, the naphthalene polyurethane prepared by prepolymerization of the 4-position naphthalene diisocyanate from Application Example 1 exhibits better tensile strength, elongation at break, and tear strength than the polyurethane prepared by prepolymerization of NDI using the same process. Furthermore, its thermal decomposition temperature exceeds 300°C. These data demonstrate that the polyurethane product prepared by the method of this invention possesses excellent properties, outstanding mechanical strength, and good heat resistance.

[0082] The above description of the embodiments is merely for the convenience of those skilled in the art to understand and use. Those skilled in the art can select appropriate production processes according to product needs. Of course, the above descriptions are only some embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A 4-position naphthalene diisocyanate, characterized in that, The structure of the 4-position naphthalene diisocyanate is shown in formula (Ⅳ). 。 2. The method for synthesizing 4-position naphthalene diisocyanate according to claim 1, characterized in that, Includes the following steps: Step 1: Halogenated acyl naphthylamine is dissolved in an organic solvent and undergoes a Ullmann reaction in the presence of a ligand and under inert gas protection, with a metal or its salt as a catalyst, to generate alkyl acyl naphthylamine. Step 2: The alkyl acyl-binaphthylamine from Step 1 is subjected to a hydrolysis reaction under acidic conditions and heated under reflux to generate binaphthyldiamine. Step 3: The binaphthyl diamine from step 2 undergoes a carbonylation reaction with a carbonylating reagent to generate binaphthyl diisocyanate.

3. The synthesis method according to claim 2, characterized in that, The organic solvent in step one is any one of anhydrous N,N-dimethylformamide, anhydrous dimethylacetamide, and anhydrous tetrahydrofuran.

4. The synthesis method according to claim 3, characterized in that, The carbonylating agent is phosgene or triphosgene.

5. The application of the 4-position naphthalene diisocyanate according to claim 1 or the 4-position naphthalene diisocyanate synthesized by the synthesis method according to any one of claims 2 to 4 in the preparation of polyurethane rubber and elastomers, polyurethane fibers, cast polyurethane rubber, polyurethane emulsions and coatings, polyurethane adhesives and polyurethane foam materials.

6. A polyurethane material, characterized in that, It is prepared by using the 4-position naphthalene diisocyanate as described in claim 1 or the 4-position naphthalene diisocyanate synthesized by the synthesis method according to any one of claims 2 to 4.

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