Furandikicarboxylic acid-based polyamide resin, its production method, and polyamide molding composition

Abstract

The present invention discloses a furandicarboxylic acid-based polyamide resin. The furandicarboxylic acid-based polyamide resin is derived from repeating units containing (A) 2,5-furandicarboxylic acid, (B) 1,4-cyclohexanedicarboxylic acid, and (C) 1,10-decanediamine, and (A) accounts for 5 to 45 mol% of the diacid units in terms of the total mol% of the diacid units. The use of bio-based 2,5-furandicarboxylic acid, which has the advantages of a melting point of 290 to 336°C, low water absorption (lower water absorption rate than polyamides with the same amide bond density), and excellent dimensional stability, improves environmental protection. On the other hand, cyclohexane has a higher rigidity than aromatic rings and can form more hard carbon layers when burned. Furthermore, furandicarboxylic acid-based polyamides have a high amide bond density and can achieve excellent synergistic effects when used in combination with flame retardants, and the synergistic effects of the two provide excellent flame retardant effects.

Description

[Technical field]

[0001] The present invention relates to the technical field of polymeric materials, and in particular to a furandicarboxylic acid-based polyamide resin, a method for producing the same, and a polyamide molding composition. [Background technology]

[0002] Traditional polyamide monomers are mainly derived from petroleum, and currently face problems such as excessive consumption of petroleum resources, rapid increase in carbon dioxide emissions, and worsening greenhouse effect. Reducing the use of petroleum-based monomers can suppress carbon dioxide emissions, prevent greenhouse effect, solve the problems of environmental pollution and resource constraints, and build a sustainable society. Bio-based high-temperature resistant polyamide mainly refers to polyamides obtained by polymerization of bio-based aliphatic diamines or bio-based aromatic diacids. Bio-based monomers are usually extracted from animals and plants, which can realize green and sustainable development, while diversifying high-temperature resistant polyamide products to meet the needs of more fragmented industries.

[0003] After market research and analysis, it is believed that the bio-based monomers decanediamine, pentylenediamine, and furandicarboxylic acid are the bio-based high-temperature resistant polyamide monomer materials most likely to achieve substantial progress. Decanediamine is derived from castor oil and has already been mass-produced in China, but its selling price is high and its market competitiveness is weak. Pentylenediamine is obtained by fermenting glutamic acid and has been mass-produced in China, with a low price and good market competitiveness. Furandicarboxylic acid is the only bio-based aromatic ring diacid monomer currently known and most likely to be industrialized in the near future. Currently, research on furandicarboxylic acid is in the trial research and development stage both at home and abroad in China.

[0004] Chinese patent application CN106536187A discloses a furan-based polyamide using bio-based monomer 2,5-furandicarboxylic acid, in which the diamine is an aliphatic diamine, an aromatic diamine, etc., and has the advantage of good gas barrier properties. However, the gas barrier properties are mainly achieved by polymerizing short carbon chain diamines (1,3-propanediamine, ) to increase the amide bond density. However, this furan polyamide has poor flame retardancy. Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the present invention is to provide a furandicarboxylic acid-based polyamide which has the advantages of excellent flame retardancy, high melting point, low water absorption and being bio-based. Another object of the present invention is to provide a composition containing the above-mentioned furandicarboxylic acid-based polyamide. [Means for solving the problem]

[0006] The present invention is achieved by the following technical solutions:

[0007] The furandicarboxylic acid-based polyamide resin is derived from repeating units containing (A) 2,5-furandicarboxylic acid, (B) 1,4-cyclohexanedicarboxylic acid, and (C) 1,10-decanediamine, and in terms of the total molar percentage of the diacid units, (A) accounts for 5 to 45 mol % of the diacid units.

[0008] Preferably, (A) accounts for 5 to 25 mol % of the diacid units, based on the total mol % of the diacid units.

[0009] More preferably, (A) accounts for 5 to 15 mol % of the diacid units, based on the total mol % of the diacid units.

[0010] Preferably, the content of (A) in the diacid units is such that the water absorption rate and the shrinkage rate are lower.

[0011] The furandicarboxylic acid-based polyamide resin has a relative viscosity of 1.8 to 2.4.

[0012] The melting point of the furandicarboxylic acid polyamide resin is 290 to 336°C.

[0013] The furandicarboxylic acid-based polyamide resin has a water absorption rate of 1.5% or less.

[0014] The furandicarboxylic acid-based polyamide resin has a shrinkage ratio in the transverse direction / longitudinal direction of 0.2% / 0.5% or less.

[0015] Add the reaction raw materials (diamine, diacid) in a specified ratio to a pressure cooker equipped with a magnetic coupling stirrer, a condenser tube, a gas phase port, a feed port, and a pressure-resistant explosion-proof port, then add benzoic acid, sodium hypophosphite (catalyst), and deionized water so that the amount of benzoic acid material is 2-3% of the total amount of diamine and diacid, the weight of sodium hypophosphite is 0.05-0.15% of the weight of other input raw materials other than deionized water, and the weight of deionized water is 25-35% of the total weight of the input raw materials, suction by vacuum, introduce protective gas as high-purity nitrogen, and stir for 2 hours. The temperature is raised to 10-230°C, the reaction mixture is stirred at 210-230°C for 0.5-2 hours, then the temperature of the reactant is raised to 220-240°C while stirring, and the reaction is continued at a constant temperature of 220-240°C and a constant pressure of 2.1-2.3MPa for 1-3 hours, the formed water is removed to keep the pressure constant, after the reaction is completed, the material is discharged, and the prepolymer is vacuum dried at 70-90°C to obtain a prepolymerization product, and the prepolymerization product is thickened in solid phase for 8-12 hours under the conditions of 240-260°C and vacuum of 40-60Pa to obtain a furandicarboxylic acid-based polyamide resin.

[0016] A polyamide molding composition comprising the components: 40 to 70 parts by weight of the furandicarboxylic acid-based polyamide resin of the present invention; 10 to 30 parts by weight of a halogen-free flame retardant; and 0 to 50 parts by weight of a reinforcing material.

[0017] The non-halogen flame retardant is at least one selected from a phosphine-based flame retardant, a phosphinate-based flame retardant, a hypophosphonite-based flame retardant, a phosphonite-based flame retardant, a phosphite-based flame retardant, a phosphine oxide-based flame retardant, a phosphinate-based flame retardant, a hypophosphite-based flame retardant, a phosphonate-based flame retardant, a phosphonate-based flame retardant, a phosphate-based flame retardant, and a polyphosphate-based flame retardant. The hypophosphite-based flame retardant is aluminum hypophosphite, calcium hypophosphite, dimethyl aluminum hypophosphite, the phosphate-based flame retardant is at least one selected from bisphenol A bis(diphenyl phosphate), phenoxyphosphazene, resorcinol (diphenyl phosphate), triphenyl phosphate, melamine polyphosphate, and melamine cyanurate; and the polyphosphate-based flame retardant is at least one selected from ammonium polyphosphate, melamine phosphate, melamine pyrophosphate, and melamine cyanurate.

[0018] The reinforcing material is at least one selected from fibrous fillers and non-fibrous fillers, the fibrous fillers are at least one selected from glass fibers, carbon fibers, basalt fibers, bamboo fibers, hemp fibers, cellulose fibers, and aramid fibers, and the non-fibrous fillers are at least one selected from alumina, carbon black, clay, zirconium phosphate, kaolin, calcium carbonate, copper powder, diatomaceous earth, graphite, mica, silica stone, titanium dioxide, zeolite, talc, wollastonite, glass beads, and glass powder.

[0019] The polyamide molding composition of the present invention can be used to manufacture various electronic connector devices that require SMT (surface mount technology), such as USB, TYPE-C, DDR, etc. These electronic devices have high requirements for the melting point, water absorption rate, and dimensional stability of the materials, and are widely used in fields such as electronics, electricity, and automobiles. Effect of the Invention

[0020] Compared with the prior art, the present invention has the following beneficial effects: 1. In the furandicarboxylic acid-based polyamide of the present invention, both diacid units contain rigid rings, and the rigidity of cyclohexane is higher than that of aromatic rings, so that a larger amount of hard carbon layer can be formed upon combustion. Furthermore, the polyamide resin of the present invention has a high amide bond density, and when used in combination with a flame retardant, it exerts an excellent synergistic effect, resulting in good flame retardancy. 2. In the present invention, by adjusting the ratio of furandicarboxylic acid to cyclohexanedicarboxylic acid, it is possible to produce a furandicarboxylic acid-based polyamide having a melting point in the range of 290 to 336°C and excellent heat resistance and processability. 3. The furandicarboxylic acid polyamide of the present invention has the advantages of low water absorption and high dimensional stability. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present invention will be described in detail below with reference to specific examples. The following examples are provided to facilitate a person skilled in the art to further understand the present invention, but are not intended to limit the present invention in any manner. However, those skilled in the art may make some modifications and improvements without departing from the concept of the present invention. All of these fall within the scope of protection of the present invention.

[0022] The origins of the raw materials used in the present invention are as follows: 2,5-Furandicarboxylic acid: 98% purity, purchased from Ningbo Institute of Materials, Chinese Academy of Sciences 1,4-Cyclohexanedicarboxylic acid: 98% purity, purchased from Sigma-Aldrich 1,6-Adipic acid: 98% purity, purchased from Sigma-Aldrich Terephthalic acid: 98% purity, purchased from Sigma-Aldrich 1,10-Decanediamine: 98% purity, purchased from Wuxi Indanelong Co., Ltd. 1,5-Pentylenediamine: 98% purity, purchased from Shanghai Kaisai Chemical Co., Ltd. 1,6-Hexamethylenediamine: 98% purity, purchased from Sigma-Aldrich Benzoic acid: analytically pure, purchased from Sigma-Aldrich Sodium hypophosphite: analytically pure, purchased from Sigma-Aldrich Halogen-free flame retardant A: Aluminum diethylphosphinate, OP1230, phosphorus content 23-24% by mass, purchased from Clariant Non-halogen flame retardant B: Melamine cyanurate, MELAPUR200-70, nitrogen mass 42-44%, phosphorus mass 12-14%, purchased from BASF Reinforcement: Glass fiber, ECS11-4.5-560A, average diameter 11 microns, purchased from China Megalith

[0023] The polyamide resins of the examples and comparative examples are obtained by the same method as follows: The reaction raw materials (diamine, diacid) are added to a pressure cooker equipped with a magnetic coupling stirrer, a condenser tube, a gas phase port, a feed port, and a pressure-resistant explosion-proof port in the proportions shown in the table, and then benzoic acid, sodium hypophosphite (catalyst), and deionized water are added so that the amount of benzoic acid material is 2% of the total weight of diamine and diacid, the weight of sodium hypophosphite is 0.08% of the weight of other input raw materials other than deionized water, and the weight of deionized water is 25% of the total weight of the input raw materials, and then vacuum suction is performed, protective gas as high-purity nitrogen is introduced, and the mixture is stirred for 2 hours. The temperature is raised to 30°C, the reaction mixture is stirred at 220°C for 0.5-2 hours, then the temperature of the reactants is raised to 240°C while stirring, the reaction is continued at a constant temperature of 240°C and a constant pressure of 2.3MPa for 1-3 hours, the formed water is removed to keep the pressure constant, after the reaction is completed, the material is discharged, the prepolymer is vacuum dried at 70-90°C to obtain a prepolymerization product, and the prepolymerization product is thickened in solid phase for 8-12 hours under vacuum conditions of 260°C and 50 Pa to obtain a furandicarboxylic acid-based polyamide (a polyamide not containing furandicarboxylic acid).

[0024] Test Method:

[0025] (1) Test method for relative viscosity of polyamide resin: For the measurement method of viscosity of polyamide, refer to GB12006.1-89. Specific test method: Measure the relative viscosity ηr of polyamide with a concentration of 0.25g / dl in 98% concentrated sulfuric acid at 25±0.01℃.

[0026] (2) Polyamide melting point test method: Refer to ASTM D3418-2003, Standard Test Method for Transition Temperatures of Polymers By Differential Scanning Calorimetry. Specific test method: Test the melting point of the sample using a Perkin Elmer Dimond DSC analyzer. Nitrogen atmosphere, flow rate 50mL / min. In the test, the sample was first heated to 350°C at 20°C / min, kept at 350°C for 2 minutes to remove the thermal history of the resin, then cooled to 50°C at 20°C / min, kept at 50°C for 2 minutes, and further heated to 350°C at 20°C / min. The endothermic peak temperature at this time was taken as the melting point Tm.

[0027] (3) Water absorption rate of polyamide: A sample is injection molded into a 20mm x 20mm x 2mm sample, and its weight is a0. After placing it in 95℃ water for 240 hours, its weight is a1. Here, water absorption rate = (a1-a0) / a0*100%.

[0028] (4) Polyamide shrinkage: The sample is injection molded into a 20mm x 10mm x 2mm sample plate, and then placed in 95°C water for 240h to measure the shrinkage after water absorption according to ISO 294-4-2018 standard.

[0029] (5) Flame retardancy: Referring to the UL94 V-0 test standard, the dimensions of the standard rod-shaped test specimen are 125±5mm in length, 13.0±0.5mm in width, and 0.8mm in thickness. Five test specimens are treated at 23±2℃ and 50±5% for a minimum of 48 hours. The Bunsen burner flame is aligned with the center of the lower end of the test specimen, and the distance between the center of the top surface of the Bunsen burner tube and the lower end surface of the test specimen is kept at 10±1mm, and this distance is maintained for 10±0.5S. If necessary, the Bunsen burner can be moved according to the change in the length position of the test specimen. Immediately after applying the flame to the test specimen for 10±0.5S, the Bunsen burner is withdrawn at a speed of about 300mm / s to a position at least 150mm away from the test specimen. At the same time, the flaming burning time T1 (unit: s) of the test specimen is measured using a timing device. After the flaming combustion of the test specimen has ceased, even if the Bunsen burner has not been moved 150 mm away from the test specimen, immediately maintain the distance from the mouth of the Bunsen burner to the bottom surface of the test specimen at 10±1 mm, and apply the flame again for 10±0.5 s, and when necessary, remove the Bunsen burner and remove the drippings, and immediately move the Bunsen burner at least 150 mm away from the test specimen after applying the flame, and at the same time start the timer to measure the flaming time T2 and the flameless burning time T3 of the test specimen, and record T2 and T3. If all five splines are T1+T2+T3<10s and the drippings do not ignite the cotton underneath, it is considered to meet the V-0 conditions.

[0030] [Table 1]

[0031] As can be seen from Examples 1 to 6, the higher the content of 1,4-cyclohexanedicarboxylic acid, the higher the melting point and the lower the water absorption rate and shrinkage rate.

[0032] [Table 2]

[0033] The furandicarboxylic acid-based polyamide resin of Comparative Example 1 / 2 has no usable value because its melting point exceeds its decomposition temperature.

[0034] As can be seen from Comparative Example 3, the higher the content of 2,5-furandicarboxylic acid, the higher the water absorption rate and shrinkage rate, the lower the melting point, and the lower the utility value.

[0035] As can be seen from Comparative Example 6, when cyclohexanedioic acid is changed to adipic acid, even though the amide bond density is reduced, the water absorption rate increases, the shrinkage rate becomes worse, and the melting point is too low.

[0036] As can be seen from Comparative Example 7, even when cyclohexane diacid is replaced with terephthalic acid having a similar structure, the water absorption rate is too high or the shrinkage rate is poor.

[0037] As can be seen from Comparative Example 8, the polyamide based on the furandicarboxylic acid / cyclohexanedioic acid / pentylenediamine segments has a poor shrinkage rate.

[0038] [Table 3]

[0039] As can be seen from Examples 7 to 12, the furandicarboxylic acid-based polyamide composition of the present invention has good flame retardancy.

[0040] [Table 4]

[0041] As can be seen from Comparative Examples 9 to 11, when the melting point is too high or too low, modification and processing / molding cannot be performed.

[0042] As can be seen from Comparative Examples 12, 13, 15, and 16, when 1,4-cyclohexanedicarboxylic acid or 1,5-pentylenediamine is changed to other diacids / diamines, the furandicarboxylic acid-based polyamide composition or other polyamide compositions have poor flame retardancy and high shrinkage in the transverse and longitudinal directions.

Claims

1. Derived from repeating units containing (A) 2,5-furandicarboxylic acid, (B) 1,4-cyclohexanedicarboxylic acid, and (C) 1,10-decanediamine, and in terms of the total mol% of the diacid units, (A) occupies 5 to 45 mol% of the diacid units, characterized in that Furandicarboxylic acid-based polyamide resin.

2. The furandicarboxylic acid-based polyamide resin according to claim 1, characterized in that in terms of the total mol% of the diacid units, (A) occupies 5 to 25 mol% of the diacid units.

3. The furandicarboxylic acid-based polyamide resin according to claim 2, characterized in that in terms of the total mol% of the diacid units, (A) occupies 5 to 15 mol% of the diacid units.

4. The furandicarboxylic acid-based polyamide resin according to claim 1, characterized in that the relative viscosity of the furandicarboxylic acid-based polyamide resin is 1.8 to 2.

4.

5. The furandicarboxylic acid-based polyamide resin according to claim 1, characterized in that the melting point of the furandicarboxylic acid-based polyamide resin is 290 to 336 °C.

6. The furandicarboxylic acid-based polyamide resin according to claim 1, characterized in that the water absorption rate of the furandicarboxylic acid-based polyamide resin is 1.5% or less, and the shrinkage rate in the transverse / longitudinal direction of the furandicarboxylic acid-based polyamide resin is 0.2% / 0.5% or less.

7. The step of adding reaction raw materials to an autoclave at a predetermined ratio, and then, the amount of benzoic acid substance is 2 to 3 mol% of the total amount of diamine and diacid, the weight of sodium hypophosphite is 0.05 to 0.15% of the weight of other input raw materials except deionized water, and the weight of deionized water is 25 to 35% of the total weight of the input raw materials. The step of adding benzoic acid, sodium hypophosphite, and deionized water; vacuum suction, introducing a protective gas as high-purity nitrogen, heating to 210 to 230 ° C within 2 hours while stirring, and stirring the reaction mixture at 210 to 230 ° C for 0.5 to 2 hours; then, while stirring, raising the temperature of the reactant to 220 to 240 ° C, and maintaining the reaction at a constant temperature of 220 to 240 ° C and a constant pressure of 2.1 to 2.3 MPa for 1 to 3 hours, removing the formed water and maintaining the pressure constant, after the reaction is completed, discharging the material, vacuum drying the prepolymer at 70 to 90 ° C to obtain a prepolymerization product, and thickening the prepolymerization product in a solid phase for 8 to 12 hours under vacuum conditions of 240 to 260 ° C and 40 to 60 Pa to obtain a phthalic acid-based polyamide resin. The method for producing a phthalic acid-based polyamide resin according to any one of claims 1 to 6, characterized by including the above steps.

8. A polyamide molding composition, which, based on 100 parts by weight of the polyamide molding composition, as components, At least 40 parts by weight of the phthalic acid-based polyamide resin according to any one of claims 1 to 6; 10 to 30 parts by weight of a non-halogen flame retardant; 0 to 50 parts by weight of a reinforcing material. A polyamide molding composition, characterized by including the above components.

9. The non-halogen flame retardant is at least one selected from phosphine flame retardants, phosphinate flame retardants, hypophosphite flame retardants, phosphonite flame retardants, phosphite flame retardants, phosphite flame retardants, phosphine oxide flame retardants, phosphinate flame retardants, hypophosphite flame retardants, phosphonate flame retardants, phosphate flame retardants, polyphosphate flame retardants or phosphinate flame retardants; the hypophosphite flame retardant is at least one selected from aluminum hypophosphite or calcium hypophosphite; the phosphinate flame retardant is at least one selected from aluminum dimethylphosphinate, aluminum diethylphosphinate or aluminum methylethylphosphinate; the phosphate flame retardant is at least one selected from bisphenol A bis(diphenyl phosphate), resorcinol (diphenyl phosphate), triphenyl phosphate or melamine phosphate; the polyphosphate flame retardant is at least one selected from ammonium polyphosphate, melamine polyphosphate, melamine pyrophosphate or melamine polyphosphate, The polyamide molding composition according to claim 8, characterized in that.

10. The reinforcing material is at least one selected from fibrous fillers and non-fibrous fillers; the fibrous filler is at least one selected from glass fiber, carbon fiber, basalt fiber, bamboo fiber, hemp fiber, cellulose fiber or aramid fiber; the non-fibrous filler is at least one selected from alumina, carbon black, clay, zirconium phosphate, kaolin, calcium carbonate, copper powder, diatomaceous earth, graphite, mica, silica, titanium dioxide, zeolite, talc, wollastonite, glass beads or glass powder, The polyamide molding composition according to claim 8, characterized in that.