3-amino-2-caprolactam derivative, nylon 6 material and preparation methods of 3-amino-2-caprolactam derivative and nylon 6 material

Abstract

The invention discloses a 3-amino-2-caprolactam derivative, a nylon 6 material and a preparation method of the 3-amino-2-caprolactam derivative, belongs to the technical field of high polymer materials, and solves the problems of high production cost and unsatisfactory application performance of a high-fluidity nylon 6 material in the prior art. The structural formula of the 3-amino-2-caprolactam derivative is shown as a formula I, # imgabs0 #, and R is an alkane carbon chain with the carbon atom number of 11-17. The 3-amino-2-caprolactam derivative provided by the invention is used as a preparation raw material of a nylon 6 material, so that the obtained nylon 6 material has higher flowability and a good demolding effect.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and more specifically to a 3-amino-2-caprolactam derivative, a nylon 6 material and a preparation method thereof. Background Art

[0002] In 2022, the global nylon 6 market size is about 14.7 billion US dollars, and the global nylon 6 production capacity has reached more than 8 million tons / year. my country is the main producer and consumer of nylon 6, with huge market demand. Nylon 6 can be divided into fiber grade, engineering plastic grade, film grade and nylon composite material according to its use. In recent years, with the development of injection molding technology, higher requirements have been put forward for the fluidity of materials.

[0003] Invention patent CN102876019A discloses a method for making a high-flowability, easy-to-release nylon 6 material. This method prepares high-flowability nylon 6 by adding additional nucleating agents and flow modifiers, blending with ordinary nylon 6, and extruding with twin screws. The preparation method is simple but requires additional processing technology, which increases production costs. At the same time, the molecular chain will inevitably break during the thermal processing process, affecting other properties of the product. Invention patent CN101148506A discloses a method for producing high-flowability nylon 6. This method prepares high-flowability nylon 6 by adding branched terminal amino compounds during the polymerization process. The melt fluidity of the resin can be increased to 2 to 3 times that of ordinary nylon with the same mechanical properties without reducing the mechanical properties. This method directly modifies the material during the polymerization process, avoids subsequent reprocessing, and can directly obtain high-flowability nylon resin from chemical raw materials; however, the addition of branched polyamino compounds used in this method may cause the nylon resin molecular chain to crosslink and produce gel, which may block the glue channel during the subsequent injection molding process.

[0004] Therefore, how to simply and efficiently prepare high-fluidity nylon 6 materials, save production costs, reduce product quality losses caused by thermal processing, and meet the higher requirements of injection molding process development for nylon resins is an urgent problem to be solved. Summary of the invention

[0005] The invention provides a 3-amino-2-caprolactam derivative, a nylon 6 material and a preparation method thereof, which are used to solve the problems of high production cost and unsatisfactory application performance of high-fluidity nylon 6 materials in the prior art.

[0006] In a first aspect, the present invention provides a 3-amino-2-caprolactam derivative, the structural formula of which is shown in Formula I,

[0007]

[0008] Wherein, R is an alkane carbon chain having 11 to 17 carbon atoms.

[0009] In a second aspect, the present invention provides a method for preparing a 3-amino-2-caprolactam derivative described in any possible implementation of the first aspect, comprising the following steps: dissolving 3-amino-2-caprolactam and a long carbon chain monofunctional acyl chloride in an organic solvent, and reflux reacting at a temperature of 100 to 120° C. for 2 to 3 hours to obtain a mixed solution; after cooling the mixed solution to room temperature, adding water to extract unreacted raw materials, collecting the upper organic phase, and spin-drying to obtain the 3-amino-2-caprolactam derivative; wherein the number of carbon atoms in the long carbon chain monofunctional acyl chloride is 12 to 18.

[0010] As a possible implementation manner, the organic solvent is toluene; and / or the amount ratio of the added amount of 3-amino-2-caprolactam and the long-chain monofunctional acyl chloride is 1:1.1-1.5; and / or the added amount of the organic solvent is 5-10 times the sum of the masses of the 3-amino-2-caprolactam and the long-chain monofunctional acyl chloride; and / or, in the water extraction, the added amount of water is 5-10 times the volume of the mixed solution.

[0011] In a third aspect, the present invention provides a nylon 6 material, which is prepared by ring-opening copolymerization of the 3-amino-2-caprolactam derivative described in any possible implementation of the first aspect or the 3-amino-2-caprolactam derivative prepared by the preparation method described in any possible implementation of the second aspect and caprolactam as preparation raw materials; the structural formula of the nylon 6 material is shown in Formula II,

[0012]

[0013] Wherein, R is an alkane carbon chain having 11 to 17 carbon atoms.

[0014] In a fourth aspect, the present invention provides a method for preparing the nylon 6 material in any possible implementation of the third aspect, comprising the following steps: adding the 3-amino-2-caprolactam derivative, the caprolactam, deionized water, a ring-opening aid, and a capping agent into a high-pressure polymerization reactor, performing a pressure-maintaining ring-opening reaction at a temperature of 220 to 240° C., releasing the pressure and performing a vacuum reaction at a temperature of 260 to 270° C. to obtain the nylon 6 material.

[0015] As a possible implementation manner, the added mass ratio of the caprolactam to the 3-amino-2-caprolactam derivative is 4 to 19:1; and / or, the mass ratio of the sum of the masses of the 3-amino-2-caprolactam derivative and the caprolactam to the mass of the deionized water is 100:0.5 to 10; and / or, the mass ratio of the sum of the masses of the 3-amino-2-caprolactam derivative and the caprolactam to the mass of the ring-opening auxiliary agent is 100:1 to 2; and / or, the mass ratio of the sum of the masses of the 3-amino-2-caprolactam derivative and the caprolactam to the mass of the end-capping agent is 100:0.5 to 1.

[0016] As a possible implementation method, the ring-opening auxiliary agent is any one of 4-aminobutyric acid, 5-aminovaleric acid, and 6-aminocaproic acid, or a combination of several thereof; and / or the end-capping agent is any one of terephthalic acid, isophthalic acid, adipic acid, and benzoic acid, or a combination of several thereof.

[0017] As a possible implementation, the pressure-maintaining ring-opening reaction lasts for 2 to 4 hours; and / or the polymerization reaction lasts for 0.8 to 1.2 hours.

[0018] The nylon 6 material provided by the present invention introduces an aminocaproic acid structural unit with a side chain structure into the monomer structure of the traditional nylon 6 material. On the one hand, the existence of the long side chain structure limits the hydrogen bonding force between the nylon 6 molecular chains, so that the movement of the molecular chains is less hindered, the fluidity thereof is improved, and the processing requirements of thin-walled and special-shaped injection molded parts can be better met; on the other hand, the introduced copolymer structure contains oleophilic and hydrophobic long carbon chain alkane side chains, and the surface of the prepared material has lower surface energy. The introduction of the long chain alkane structure can reduce the surface tension of the resin melt during the processing, thereby achieving the effect of easy demoulding.

[0019] The present invention proposes a structurally improved preparation method for the current high-fluidity nylon 6 material, which has a complicated preparation process and poor subsequent application effect, and provides a series of 3-amino-2-caprolactam derivatives, and provides a method for introducing the series structure into the traditional nylon 6 structure to prepare a high-fluidity, easy-to-demold nylon 6 material. Specifically, the 3-amino-2-caprolactam series monomers provided by the present invention have long alkane side chains, which can weaken the hydrogen bonding force between nylon 6 molecular chains when introduced into the nylon 6 structure, making the movement of the molecular chains less hindered and the resin melt more fluid; and the long alkane chain in the structure has a lower surface energy, and the prepared material has a good demolding effect during the injection molding process. In addition, the preparation process does not require additional heat treatment operations, and the preparation process is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 This is an optical photograph of water contact angle provided by an embodiment of the present invention, wherein a is nylon 6 material VIII, and b is nylon 6 material II.

[0022] Figure 2 The differential scanning calorimetry cooling crystallization process curve diagram of nylon 6 material VIII and nylon 6 material II provided in the embodiments of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In order to solve the problems of high production cost and unsatisfactory application performance of high-fluidity nylon 6 materials in the prior art, an embodiment of the present invention provides a preparation experiment of a 3-amino-2-caprolactam derivative, and provides an experiment of preparing a nylon 6 material using the 3-amino-2-caprolactam derivative as a raw material. Characterization of the product shows that with the increase of the side chain length of one of the raw materials, the fluidity of the obtained nylon 6 material is significantly improved; with the increase of the addition amount of the 3-amino-2-caprolactam derivative, the fluidity of the resin is significantly enhanced, which confirms the effective gain of the structure designed by the present invention in improving the fluidity of the nylon 6 resin.

[0025] Furthermore, the present invention provides a demolding experiment of nylon 6 material, and it can be seen that nylon 6 material I to nylon 6 material IX all show excellent demolding effect, while nylon 6 material VIII and nylon 6 material IX are difficult to demold automatically without additionally adding a demolding agent.

[0026] Furthermore, an embodiment of the present invention provides a surface contact angle test and thermal change analysis of a nylon 6 material. It can be seen that the material prepared by the present invention has a smaller surface energy, a lower crystallization temperature, and a narrower crystallization exothermic peak. These characteristics make the nylon 6 material provided by the present invention easier to demold.

[0027] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0028] Example 1

[0029] This example provides an experiment for preparing a 3-amino-2-caprolactam derivative.

[0030] 12.8 g of 3-amino-2-caprolactam was added to a round-bottom flask (500 mL) containing 183.9 g of toluene, and 23.98 g of lauroyl chloride was added, and the mixture was refluxed at 110°C for 2 h. After the reaction, 920 g of water was added to extract the liquid, and the upper organic phase was collected and distilled under reduced pressure to obtain 3-amino-2-caprolactam derivative I, which had 12 branched carbon atoms.

[0031] 12.8 g of 3-amino-2-caprolactam was added to a round-bottom flask (500 mL) containing 240 g of toluene, and 27.15 g of myristic acid chloride was added, and the mixture was refluxed at 110°C for 2.5 h. After the reaction was completed, 1440 g of water was added to extract the liquid, and the upper organic phase was collected and distilled under reduced pressure to obtain 3-amino-2-caprolactam derivative II, which had 14 branched carbon atoms.

[0032] 12.8 g of 3-amino-2-caprolactam was added to a round-bottom flask (1000 mL) containing 390 g of toluene, and 35.73 g of palmitoyl chloride was added, and the mixture was refluxed at 110° C. for 2.5 h. After the reaction was completed, 3120 g of water was added to extract the liquid, and the upper organic phase was collected and distilled under reduced pressure to obtain 3-amino-2-caprolactam derivative III, which had 16 branched carbon atoms.

[0033] 12.8 g of 3-amino-2-caprolactam was added to a round-bottom flask (1000 mL) containing 582 g of toluene, and 45.4 g of stearoyl chloride was added, and the mixture was refluxed at 110° C. for 2.5 h. After the reaction was completed, 5500 g of water was added to extract the liquid, and the upper organic phase was collected and distilled under reduced pressure to obtain 3-amino-2-caprolactam derivative IV, which had 18 branched carbon atoms.

[0034] 12.8 g of 3-amino-2-caprolactam was added to a round-bottom flask (1000 mL) containing 455 g of toluene, and 32.7 g of lauroyl chloride was added, and the mixture was refluxed at 110° C. for 3 h. After the reaction was completed, 3640 g of water was added to extract the liquid, and the upper organic phase was collected and distilled under reduced pressure to obtain 3-amino-2-caprolactam derivative V, which had 12 branched carbon atoms.

[0035] 12.8 g of 3-amino-2-caprolactam was added to a round-bottom flask (1000 mL) containing 310 g of toluene, and 28.44 g of lauroyl chloride was added, and the mixture was refluxed at 110° C. for 2.5 h. After the reaction was completed, 2325 g of water was added to extract the liquid, and the upper organic phase was collected and distilled under reduced pressure to obtain 3-amino-2-caprolactam derivative VI, which had 12 branched carbon atoms.

[0036] Example 2

[0037] This embodiment provides a preparation experiment of nylon 6 material.

[0038] 190g of caprolactam, 10g of the 3-amino-2-caprolactam derivative to be tested, 10g of deionized water, 4g of 6-aminocaproic acid, and 1g of benzoic acid were added to a 1L autoclave, heated to 230°C and reacted under pressure for 3h, and then heated to 260°C and reacted for 1h to obtain nylon 6 material. In this example, the 3-amino-2-caprolactam derivatives I to 3-amino-2-caprolactam derivatives IV prepared in Example 1 were used as the 3-amino-2-caprolactam derivatives to be tested, respectively, to prepare nylon 6 materials I to nylon 6 materials IV.

[0039] 180 g of caprolactam, 20 g of 3-amino-2-caprolactam derivative V prepared in Example 1, 10 g of deionized water, 4 g of 6-aminocaproic acid and 1 g of benzoic acid were added to a 1 L high pressure reactor, the temperature was raised to 230° C. and the pressure was maintained for reaction for 3 h, and the temperature was further raised to 260° C. and the reaction was carried out for 1 h to obtain nylon 6 material V.

[0040] 170 g of caprolactam, 30 g of the 3-amino-2-caprolactam derivative VI prepared in Example 1, 10 g of deionized water, 4 g of 6-aminocaproic acid and 1 g of benzoic acid were added to a 1 L high pressure reactor, the temperature was raised to 230° C. and the pressure was maintained for reaction for 3 h, and the temperature was further raised to 260° C. and the reaction was carried out for 1 h to obtain nylon 6 material VI.

[0041] 160 g of caprolactam, 40 g of 3-amino-2-caprolactam derivative VI prepared in Example 1, 10 g of deionized water, 4 g of 6-aminocaproic acid and 1 g of benzoic acid were added to a 1 L high pressure reactor, the temperature was raised to 230° C. and the pressure was maintained for reaction for 3 h, and the temperature was further raised to 260° C. and the reaction was carried out for 1 h to obtain nylon 6 material VII.

[0042] A commercially available nylon 6 material with the brand number BL3280 was used as nylon 6 material VIII.

[0043] A commercially available nylon 6 material with the brand name Ultramid B was used as nylon 6 material IX.

[0044] Example 3

[0045] This example provides a characterization experiment of nylon 6 material.

[0046] The melt mass flow rate parameters of nylon 6 materials I to nylon 6 materials IX prepared in Example 2 were measured by the method described in GB / T 3682.1-2018, and the results shown in Table 1 were obtained.

[0047] Table 1 Melt index results of nylon 6 materials

[0048] Material Number of carbon atoms in the side chain of raw materials Melt index (g / 10min) Nylon 6 MaterialⅠ 12 8.5 Nylon 6 Material Ⅱ 14 10.2 Nylon 6 Material Ⅲ 16 11.8 Nylon 6 Material Ⅳ 18 13.4 Nylon 6 Material Ⅴ 12 10.6 Nylon 6 Material VI 12 13.4 Nylon 6 Material VII 12 16..2 Nylon 6 Material VIII \ 3.4 Nylon 6 Material Ⅸ \ 5.2

[0049] As shown in Table 1, as the length of the side chain of one of the raw materials, 3-amino-2-caprolactam derivative, increases, the fluidity of the prepared nylon 6 material is significantly improved. The results of nylon 6 material I, nylon 6 material V, nylon 6 material VI and nylon 6 material VII show that as the amount of 3-amino-2-caprolactam derivative added increases, the fluidity of the resin is significantly enhanced, confirming the effective gain of the structure designed by the present invention in improving the fluidity of nylon 6 resin.

[0050] Example 4

[0051] This embodiment provides a demoulding experiment of nylon 6 material.

[0052] The nylon 6 material to be tested was injection molded on the same injection molding machine. The injection molding conditions were: temperature 250°C, pressure 60%, time 5s, holding pressure 60%, holding time 6s, and cooling 5s. Then, when demolding, the sample was observed for mold sticking. The fully automatic mode was used to statistically test the injection mold within five minutes.

[0053] In this embodiment, nylon 6 materials I to nylon 6 materials IX of embodiment 2 are used as nylon 6 materials to be tested, and injection molding demolding tests of thin-walled special-shaped parts are carried out, and the results shown in Table 2 are obtained.

[0054] Table 2 Demolding test results

[0055]

[0056] As can be seen from Table 2, nylon 6 material I to nylon 6 material VII all exhibit excellent demoulding effects, while nylon 6 material VIII and nylon 6 material IX are difficult to demould automatically without the addition of additional release agents.

[0057] The surface contact angle of nylon 6 material II and nylon 6 material VIII of Example 2 was tested. The results are as follows: Figure 1As shown in the figure, it can be seen that the contact angle of nylon 6 material II is larger, which means that after the introduction of 3-amino-2-caprolactam derivatives, the surface energy of the material is smaller. The smaller surface energy can make the material have less force with the metal mold surface during the injection molding demolding process, which is more conducive to demolding. Under the same test conditions, the heat change of the prepared nylon 6 material II and nylon 6 material VIII during the cooling process was analyzed. Figure 2 The results shown show that the crystallization temperature of nylon 6 material II is lower and the crystallization exothermic peak is narrower, which means that after adding 3-amino-2-caprolactam derivatives, the crystallization process of the material occurs in a shorter time and the material crystallizes more rapidly, which can make the product cool and harden faster during the injection molding process and is more conducive to demolding.

[0058] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0059] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A 3-amino-2-caprolactam derivative, characterized in that: Its structural formula is shown in Formula I, Wherein, R is an alkane carbon chain having 11 to 17 carbon atoms.

2. A method for preparing the 3-amino-2-caprolactam derivative according to claim 1, characterized in that: The following steps are involved: Dissolving 3-amino-2-caprolactam and long carbon chain monofunctional acyl chloride in an organic solvent, and reflux reaction at 100-120° C. for 2-3 hours to obtain a mixed solution; After the mixed solution is cooled to room temperature, water is added to extract the unreacted raw materials, and the upper organic phase is collected and spin-dried to obtain the 3-amino-2-caprolactam derivative; Wherein, the number of carbon atoms in the long carbon chain monofunctional acyl chloride is 12-18.

3. The preparation method according to claim 2, characterized in that: The organic solvent is toluene; And / or, the molar ratio of the 3-amino-2-caprolactam to the long carbon chain monofunctional acyl chloride is 1:1.1-1.5; And / or, the amount of the organic solvent added is 5 to 10 times the sum of the mass of the 3-amino-2-caprolactam and the long carbon chain monofunctional acyl chloride; And / or, in the water extraction, the amount of water added is 5 to 10 times the volume of the mixed solution.

4. A nylon 6 material, characterized in that: The 3-amino-2-caprolactam derivative according to claim 1 or the 3-amino-2-caprolactam derivative prepared by the preparation method according to any possible implementation mode of claims 2 to 3 and caprolactam are used as preparation raw materials and are prepared by ring-opening copolymerization; The structural formula of the nylon 6 material is shown in Formula II. Wherein, R is an alkane carbon chain having 11 to 17 carbon atoms.

5. A method for preparing the nylon 6 material according to claim 4, characterized in that: The following steps are involved: The 3-amino-2-caprolactam derivative, the caprolactam, deionized water, a ring-opening aid and a capping agent are added into a high-pressure polymerization reactor, and a pressure-maintaining ring-opening reaction is carried out at a temperature of 220 to 240° C. The pressure is released and a vacuum is drawn to carry out a polymerization reaction at a temperature of 260 to 270° C. to obtain the nylon 6 material.

6. The preparation method according to claim 5, characterized in that: The added mass ratio of the caprolactam to the 3-amino-2-caprolactam derivative is 4 to 19:1; and / or, the ratio of the sum of the mass of the 3-amino-2-caprolactam derivative and the caprolactam to the mass of the deionized water is 100:0.5-10; and / or, the ratio of the sum of the mass of the 3-amino-2-caprolactam derivative and the caprolactam to the mass of the ring-opening auxiliary agent is 100:1-2; And / or, the ratio of the sum of the masses of the 3-amino-2-caprolactam derivative and the caprolactam to the mass of the end-capping agent is 100:0.5-1.

7. The preparation method according to claim 5, characterized in that: The ring-opening auxiliary agent is any one or a combination of 4-aminobutyric acid, 5-aminovaleric acid, and 6-aminocaproic acid; And / or, the end-capping agent is any one of terephthalic acid, isophthalic acid, adipic acid, and benzoic acid, or a combination of several of them.

8. The preparation method according to claim 5, characterized in that: The pressure-maintaining ring-opening reaction lasts for 2 to 4 hours; And / or, the polymerization reaction lasts for 0.8 to 1.2 hours.

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