A transparent nylon elastomer and a method for preparing the same

Abstract

The application discloses a kind of transparent nylon elastomer and its preparation method, it is related to polyamide technical field, solve the technical problems that existing transparent polyamide cannot simultaneously satisfy high transparency, good softness.The transparent nylon elastomer of the present application is copolymerized by monomer A, monomer B and monomer C, and the total amount is 100%, according to mass percentage, the proportion of monomer A is 40-55%, the proportion of monomer B is 40-50%, the proportion of monomer C is 5-20%, the monomer A is the blend of decanediamine and adipic acid, the monomer B is the blend of polyetheramine with molecular weight of 900-1500 and adipic acid, the monomer C is the blend of alicyclic diamine monomer and adipic acid, and the alicyclic diamine monomer is one of MACM, PACM or a mixture of two.The present application has the advantages of high transparency, good softness, good anti-precipitation, good ethanol resistance and wide application.

Description

Technical Field

[0001] This invention belongs to the field of polyamide technology, specifically relating to a transparent nylon elastomer and its preparation method. Background Technology

[0002] Nylon was the first fiber to appear in the world; it is another name for polyamide fiber.

[0003] Transparent nylon material is a type of polyamide with an amorphous or microcrystalline structure. Compared with other conventional transparent materials such as polycarbonate (PC), polymethyl methacrylate (PMMA), and polystyrene (PS), it has higher mechanical strength, thermal stability, excellent corrosion resistance, scratch resistance, and stress crack resistance. It can be used not only for beverage and food packaging, but also as packaging material for precision instruments, meters, pharmaceuticals, and chemicals, and for producing moisture-proof and shock-absorbing cushions and foamed boards.

[0004] Traditional transparent nylon materials are relatively stiff and do not meet the increasing demands for processing performance, multiple shapes, and multiple uses. Although many softeners have emerged in the polyamide field to improve the softness of nylon, finding a way to improve softness without affecting transparency or even improve transparency is a technical problem that this field continues to solve.

[0005] Furthermore, in current transparent nylon elastomers, lactams are commonly used as crystalline monomers, and no alternative crystalline monomer has yet been found to achieve good results. Therefore, how to design a transparent nylon elastomer that does not have high requirements for raw materials, is highly transparent and soft, and has excellent other comprehensive properties is an important problem that urgently needs to be solved in this field. Summary of the Invention

[0006] This invention discloses a transparent nylon elastomer and its preparation method, aiming to solve the technical problem that existing nylon materials cannot get rid of the limitation of lactam raw materials, and to meet the requirements of high softness and high transparency while maintaining good comprehensive performance.

[0007] To solve the aforementioned technical problems, the present invention adopts the following technical solution:

[0008] A transparent nylon elastomer is copolymerized from monomers A, B, and C, which together account for 100% of the total amount. By mass percentage, monomer A accounts for 40-55%, monomer B accounts for 40-50%, and monomer C accounts for 5-20%. Monomer A is a blend of decanediamine and adipic acid, monomer B is a blend of polyetheramine with a molecular weight of 900-1500 and adipic acid, and monomer C is a blend of alicyclic diamine monomer and adipic acid. The alicyclic diamine monomer is one or a mixture of MACM and PACM.

[0009] This invention takes into account the current requirements for transparency and softness of nylon, as well as the increasingly higher requirements for comprehensive properties such as ethanol resistance and water absorption. The design focuses on the combination of comonomers. The main concept is to use monomer A, which has good crystallinity, specifically a blend of decanediamine and adipic acid. This monomer dominates the formation of better crystals. Monomer B, as the soft segment, is a blend of polyetheramine with a higher molecular weight and adipic acid, which adjusts the softness of the nylon. Monomer C, a blend of alicyclic diamine monomer and adipic acid, adjusts the degree of crystallization randomness and controls the microcrystalline region. Through the combination of monomers A, B, and C, and by adjusting the crystal structure and size, a transparent nylon elastomer with high transparency, good softness, and good ethanol resistance is obtained.

[0010] The present invention preferably provides a transparent nylon elastomer, wherein monomer B accounts for 45-50% of the total mass of the transparent nylon elastomer.

[0011] This invention uses monomer B with a high content and monomer A with a high degree of crystallinity, as well as alicyclic compounds to adjust the microcrystalline region, in order to ensure high transparency and other comprehensive properties while improving the softness of nylon.

[0012] The present invention preferably provides a transparent nylon elastomer, wherein the polyetheramine is one or a mixture of two of polytetrahydrofuran diamine or polyether diamine.

[0013] The present invention preferably provides a transparent nylon elastomer, wherein the polyetheramine is a polytetrahydrofuran diamine with a molecular weight of 900-1100.

[0014] This invention uses a mixture of polytetrahydrofuran diamine with a molecular weight of 900-1100 and adipic acid as monomer B, which, together with monomer A (which can form high crystallinity) and alicyclic monomer C, forms a highly transparent and soft nylon elastomer.

[0015] The present invention preferably provides a transparent nylon elastomer, wherein the polyetheramine is a polyether diamine with a molecular weight of 1000-1500.

[0016] This invention uses a mixture of polyether diamine with a molecular weight of 1000-1500 and adipic acid as monomer B, which, together with monomer A (which can form high crystallinity) and alicyclic monomer C, forms a highly transparent and soft nylon elastomer.

[0017] The present invention preferably provides a transparent nylon elastomer, wherein the molar ratio of sebacic acid and adipic acid in monomer A is 1±0.02:1±0.02.

[0018] The present invention preferably provides a transparent nylon elastomer, wherein the alicyclic diamine monomer is MACM.

[0019] A method for preparing a transparent nylon elastomer, comprising the following steps:

[0020] Step 1: Add monomers A, B, C and catalyst to the polymerization reactor;

[0021] Step 2: Purge with nitrogen, maintaining the pressure at 0.3-1.0 MPa;

[0022] Step 3: Heat the solution to 100-140℃ and stir for 1-3 hours.

[0023] Step 4: Continue heating to 220-260℃ and hold at pressure for 1-3 hours;

[0024] Step 5: Reduce the pressure to 0 MPa, and vacuum for 5-240 minutes according to the required viscosity to obtain transparent nylon elastomer.

[0025] This invention employs a one-pot method to copolymerize monomers A, B, and C under the action of a catalyst to form a transparent nylon elastomer. The method is simple, low-cost, and yields a transparent nylon elastomer with excellent properties.

[0026] The present invention preferably provides a method for preparing a transparent nylon elastomer, wherein the catalyst comprises one or a mixture of two of hypophosphorous acid, phosphoric acid, and hypophosphite.

[0027] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0028] 1. This invention selects special decanediamine and adipic acid as crystallizing monomers, uses a mixture of polyether diamine of monomer B and adipic acid as the soft segment, and adjusts the degree of randomization of crystallization by alicyclic compounds to control the microcrystalline region. Through the combination of the three monomer types and amounts, it gives it a special crystal structure and crystal size, thereby improving the softness of transparent nylon and obtaining a high-performance transparent nylon elastomer with a transparency of over 90%, a hardness of 40-50D, and excellent resistance to ethanol and other properties.

[0029] 2. In preparing transparent nylon elastomers, this invention selects sebacic acid and adipic acid as crystalline monomers, and by combining polyetheramine monomers with special molecular weights and alicyclic monomers, it can replace the existing high-priced lactams as semi-crystalline monomers, thereby reducing material costs and overcoming the technical limitations on raw materials in this field.

[0030] 3. The transparent nylon elastomer of the present invention is synthesized by a one-pot method, which is simple and has excellent performance. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] Example 1:

[0033] This embodiment provides a transparent nylon elastomer copolymerized from monomers A, B, and C, with a total mass of 100%. Monomer A is a blend of decanediamine and adipic acid in a molar ratio of 1.02:1. Monomer B is a mixture of polytetrahydrofuran diamine with a molecular weight of 1000 and adipic acid. Monomer C is a mixture of an alicyclic monomer and adipic acid, wherein the alicyclic monomer is MACM. The mass percentages of monomers A, B, and C are 45%, 45%, and 10%, respectively.

[0034] The preparation method of transparent nylon elastomer is as follows:

[0035] Step 1: Weigh 4.5 kg of monomer A, 4.5 kg of monomer B, 1 kg of monomer C and 10 g of catalyst hypophosphoric acid and add them to the polymerization reactor;

[0036] Step 2: Purge with nitrogen, maintaining the pressure at 0.5 MPa;

[0037] Step 3: Heat the solution to 120 ℃ and stir for 2 h;

[0038] Step 4: Continue heating to 240 ℃ and hold at pressure for 2 hours;

[0039] Step 5: Reduce the pressure to 0 MPa, evacuate for 60 min and then discharge to obtain transparent nylon elastomer.

[0040] Examples 2-4

[0041] The difference between Example 2 and Example 1 is that the diacid used in monomers A / B / C contains 4 carbons.

[0042] The difference between Example 3 and Example 1 is that the dicarboxylic acid used in monomers A / B / C contains 9 carbons.

[0043] The difference between Example 4 and Example 1 is that the diacid used in monomers A / B / C contains 12 carbons.

[0044] Examples 5-8:

[0045] The difference between Examples 5-8 and Example 1 is that the molecular weights of the polytetrahydrofuran diamine are 700, 900, 1100 and 1500, respectively.

[0046] Examples 9-10

[0047] The difference between Example 9 and Example 1 is that the alicyclic monomer is only PACM.

[0048] The difference between Example 10 and Example 1 is that the alicyclic monomer is a mixture of PACM and MACM in a molar ratio of 1:1.

[0049] Examples 11-15

[0050] The difference between Examples 11-15 and Example 1 is that the proportions of monomer B are 20%, 30%, 40%, 50%, and 55%, respectively, and the proportions of monomer A are 70%, 60%, 50%, 40%, and 35%, respectively.

[0051] Examples 16-20

[0052] The difference between Examples 16-20 and Example 1 is that the polyetheramine in monomer B is a mixture of polyether diamine and adipic acid, and the molecular weight of the polyether diamine is 800, 1000, 1200, 1500, or 1800.

[0053] Comparative Example 1

[0054] The difference between this embodiment and Embodiment 1 is that monomer A is a dodecanolactam.

[0055] Comparative Example 2

[0056] The difference between this comparative example and Example 1 is that it does not contain monomer B.

[0057] Comparative Example 3

[0058] The difference between this comparative example and Example 1 is that it does not contain monomer C.

[0059] Comparative Example 4

[0060] The difference between this comparative example and Example 1 is that monomer A is dodecanolactam, and the molecular weight of polytetrahydrofuran diamine in monomer B is 650, and the amount added is 25%.

[0061] The performance of Examples 1-20 and Comparative Examples 1-4 was tested, and the results are shown in Table 1 below.

[0062] Table 1. Performance results of nylon elastomers obtained from different embodiments and comparative examples

[0063]

[0064] Note: "+" indicates an increase. NB, or Not Break, means that the device does not break under the impact of a 4.0J pendulum, based on the ISO 179 test standard.

[0065] UV resistance: The change in yellowness index of a 2mm thick plate after 500 hours of UV irradiation was measured according to ASTM D 1925. The smaller the change in yellowness index, the better the UV resistance of the material. The UV light source used had a wavelength of 340nm and an irradiation intensity of 0.5W / m². 2 The color difference value △E is evaluated by comparing the color difference before and after aging.

[0066] Anti-precipitation performance: A 60x60x2mm sample was aged for 240 hours at 40℃ and 95% humidity. After drying the sample at 23℃, the haze was measured according to ASTM D 1003. The smaller the change in haze, the better the material's anti-precipitation performance.

[0067] Ethanol resistance: A 60x60x2mm sample was immersed in 90% ethanol for 5 minutes at 23°C. After drying the sample at 23°C, the haze was measured according to ASTM D 1003. The smaller the change in haze, the better the ethanol resistance of the material.

[0068] The performance obtained from the above embodiments and comparative examples shows that:

[0069] (1) By comparing Example 1 with Examples 2-4, it was found that: under the condition that other parameters remain unchanged, the transparency of the final transparent nylon elastomer first increases and then decreases with the increase of carbon chain of crystalline monomer, while the melting point gradually decreases. This is mainly because the transparency is mainly affected by the crystal structure and size. In this invention, the crystal structure and size are obtained by using decanediamine and adipic acid as crystalline monomers, and with special content, special molecular weight and special type of monomers B and C, which makes the nylon have high comprehensive properties such as crystallinity, melting point and hardness.

[0070] (2) By comparing Example 1 with Examples 5-8, it was found that: when other parameters remain unchanged, the polytetrahydrofuran diamine of monomer B has little effect on transparency, indicating that it has little effect on crystal structure and size. Therefore, the transparency is almost unchanged. However, since monomer B is a soft segment monomer, its increased molecular weight will lead to a decrease in hardness. As for the melting point, it is mainly affected by the proportion of crystalline monomers, so the change is not significant. As for water absorption and anti-precipitation, when the molecular weight of polytetrahydrofuran diamine is too small, such as 700 in Example 7, the density of amide groups increases and the water absorption increases slightly. Unreacted small molecules are more likely to precipitate. Therefore, the water absorption increases and the anti-precipitation ability deteriorates.

[0071] (3) By comparing Example 1 with Examples 9-10, it was found that the performance of the final transparent nylon is not significantly affected by the alicyclic monomer C being either MACM or PACM, or by a mixture of MACM and PACM.

[0072] (4) By comparing Example 1 with Examples 11-15, it was found that: the ratio of hard segment crystalline monomer A to soft segment monomer B affects the structure and size of the crystals. Specifically, in this invention, when the proportion of monomer A is between 45% and 70%, the transparency gradually decreases as the proportion of monomer A increases. When the proportion of monomer A is between 35% and 45%, the transparency gradually increases as the proportion of monomer A increases. When the proportions of both monomer A and monomer B are 45%, the transparency is the highest, and other comprehensive properties are also good. Secondly, the ratio of hard segment crystalline monomer A to soft segment monomer B is directly related to hardness and melting point. The higher the proportion of hard segment crystalline monomer A and the lower the proportion of soft segment monomer B, the higher the hardness and melting point. Conversely, the lower the hardness and melting point, the lower the hardness and melting point. Finally, the change in the ratio of hard segment to soft segment determines the linear change in mechanical properties. The higher the proportion of hard segment and the lower the proportion of soft segment, the worse the impact resistance and the better the tensile strength. When the proportions of both monomer A and monomer B are 45%, a transparent nylon elastomer with good comprehensive mechanical properties can be obtained.

[0073] (5) By comparing Example 1 with Examples 16-20, it was found that when polyether diamine is used in monomer B, its molecular weight increases from 800 to 1500, and its hardness gradually decreases. The molecular weight range with better transparency, hardness and other properties is 100-1500.

[0074] (6) The test results of Comparative Examples 1-4 show that the nylon obtained by changing the raw materials of monomer A and the ratio of monomer A and monomer B compared with the present invention cannot simultaneously meet the requirements of transparency and softness.

[0075] The above analysis shows that:

[0076] (1) This invention uses decanediamine and adipic acid as hard segments for special crystallization, and a mixture of polytetrahydrofuran diamine and adipic acid with a content of 45-50% and a molecular weight of 900-1100 as soft segments to increase flexibility. Furthermore, it adjusts the degree of randomization of crystallization, controls the alicyclic monomers in the microcrystalline region, and the alicyclic monomers are either MACM or PACM, or a mixture of MACM and PACM. By combining these three aspects, a transparent nylon elastomer with a crystallinity of 90% or higher and a hardness of 40-50D is obtained. Moreover, its comprehensive performance is excellent and can meet the needs of various occasions.

[0077] (2) From the perspective of the selection of crystallizing monomers, when monomer A is decanediamine and adipic acid as crystallizing monomers, it can copolymerize with monomers B and C to obtain transparent nylon monomers with higher transparency, better softness, and better ethanol resistance.

[0078] (3) Regarding the selection of polyetheramines for monomer B, only when the polyetheramine is polytetrahydrofuran diamine with a molecular weight of 900-1100 and the addition amount is 45% or more, can a transparent nylon monomer with higher transparency, better softness, and better ethanol resistance be obtained.

[0079] (4) In terms of monomer C, when MACM, PACM or a mixture of the two are selected, transparent nylon monomers with excellent transparency, good softness and good ethanol resistance can be obtained.

[0080] (5) The comparison results of Example 1 and Comparative Example 1 show that the present invention achieves better overall performance than using dodecanolactam as a crystallizing monomer by selecting decanediamine and adipic acid as crystallizing monomers and combining them with special types and amounts of polyetheramine and alicyclic compounds. This is of great value to the art.

[0081] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transparent nylon elastomer, characterized in that, The monomer is copolymerized in a one-pot process from monomers A, B, and C, which together account for 100% of the total mass. By mass percentage, monomer A accounts for 40-55%, monomer B accounts for 40-50%, and monomer C accounts for 5-20%. Monomer A is a blend of decanediamine and adipic acid. Monomer B is a blend of polyetheramine with a molecular weight of 900-1500 and adipic acid. The polyetheramine is polytetrahydrofuran diamine. Monomer C is a blend of alicyclic diamine monomer and adipic acid. The alicyclic diamine monomer is one or a mixture of MACM and PACM.

2. The transparent nylon elastomer according to claim 1, characterized in that, The monomer B accounts for 45-50% of the total mass of the transparent nylon elastomer.

3. A transparent nylon elastomer according to claim 1 or 2, characterized in that, The molecular weight of the polytetrahydrofuran diamine is 900-1100.

4. A transparent nylon elastomer according to claim 1 or 2, characterized in that, The molar ratio of decanediamine to adipic acid in monomer A is 1 ± 0.02: 1 ± 0.

02.

5. A method for preparing a transparent nylon elastomer, used to prepare the transparent nylon elastomer according to any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Add monomers A, B, C and catalyst to the polymerization reactor; Step 2: Purge with nitrogen, maintaining the pressure at 0.3-1.0 MPa; Step 3: Heat the solution to 100-140℃ and stir for 1-3 hours. Step 4: Continue heating to 220-260℃ and hold at pressure for 1-3 hours; Step 5: Reduce the pressure to 0 MPa, evacuate for 5-240 minutes, and then discharge to obtain transparent nylon elastomer.

6. The method for preparing the transparent nylon elastomer according to claim 5, characterized in that, The catalyst comprises one or a mixture of two of hypophosphoric acid, phosphoric acid, and hypophosphite.

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