阅读说明：本技术 一种高纯度的尼龙5x盐及其纯化方法 (High-purity nylon 5X salt and purification method thereof ) 是由 董华 董筱雯 杨晨 刘修才 于 2019-04-19 设计创作，主要内容包括：本发明涉及一种高纯度的尼龙5X盐及其制备方法。其中,所述尼龙5X盐的纯度达到99.5％以上,可直接用于聚合。发明所提供的尼龙5X盐的制备方法,以及将戊二胺和尼龙盐生产工艺耦合在一起,一步法生产尼龙盐的方法,省去了繁琐复杂的工艺流程,减少设备投资,节约生产成本。并且,本申请所提供的方法解决了水溶液法尼龙盐结晶产品收率低的问题,更有效地控制结晶过程,避免了爆析成核。(The invention relates to a high-purity nylon 5X salt and a preparation method thereof. Wherein, the purity of the nylon 5X salt reaches more than 99.5 percent, and the nylon 5X salt can be directly used for polymerization. The preparation method of the nylon 5X salt, which is provided by the invention, couples the production processes of the pentamethylene diamine and the nylon salt together, and produces the nylon salt by a one-step method, thereby saving the complicated process flow, reducing the equipment investment and saving the production cost. In addition, the method provided by the application solves the problem of low yield of the nylon salt crystallization product by the aqueous solution method, more effectively controls the crystallization process, and avoids explosive precipitation and nucleation.)

1. The nylon 5X salt is characterized in that the purity of the nylon 5X salt reaches more than 99.5 percent; and/or the presence of a gas in the gas,

50% cumulative volume particle size D of the Nylon 5X salt₅₀150 to 350 μm; and/or the presence of a gas in the gas,

the bulk density of the nylon 5X salt is 0.45-0.6 g/cm³。

2. A method for purifying a nylon 5X salt is characterized by mainly comprising the following steps:

(1) mixing the crude nylon 5X salt with an alcohol/water mixed solution to obtain a mixture of nylon 5X salt;

(2) heating the mixture of the nylon 5X salt prepared in the step (1) to a temperature T1, preserving heat, cooling, and preserving heat again;

(3) cooling to the temperature T3, and keeping the temperature;

(4) centrifuging, washing and drying for 2-10 hours to obtain nylon 5X salt;

the crude nylon 5X salt is obtained by taking pentanediamine from a biomass source as a raw material and carrying out a polymerization reaction with aliphatic dibasic acid, preferably, the aliphatic dibasic acid comprises one of adipic acid, succinic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid and hexadecanedioic acid without limitation.

3. The method of claim 2, wherein in the step (1), the alcohol in the alcohol/water mixed solution is one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, pentanol or octanol; and/or the presence of a gas in the gas,

the concentration of the alcohol/water mixed solution is 60-99 wt.%, preferably 65-96 wt.%.

4. The method according to claim 2, wherein the mass fraction of the crude nylon 5X salt in the mixture of nylon 5X salts is 45-85%, preferably 50-80%.

5. The method of claim 2, wherein in step (2), the temperature T1 is 40-75 ℃, preferably 45-70 ℃; and/or the presence of a gas in the gas,

the heat preservation time U1 is 0.5-2 h, preferably 0.5-1.5 h; and/or the presence of a gas in the gas,

the time U2 for heat preservation again is 0.5-2.5 h, preferably 1-1.5 h.

6. The method according to claim 2, wherein in step (3), the temperature T3 is 10-35 ℃, preferably 15-30 ℃; and/or the presence of a gas in the gas,

the cooling rate is 2-15 min/DEG C, and preferably 4-9 min/DEG C; and/or the presence of a gas in the gas,

the time U3 is 0.5-2 h, preferably 0.5-1 h.

7. The method of claim 2, wherein, in step (4),

the washing is carried out by leaching in alcohol or alcohol/water mixed solution at ambient temperature;

the alcohol is one or more of methanol, ethanol, n-propanol, isopropanol, butanol, 2-butanol, pentanol or octanol; and/or the presence of a gas in the gas,

the alcohol in the alcohol/water mixed solution is one or more of methanol, ethanol, n-propanol, isopropanol, butanol, 2-butanol, pentanol or octanol.

8. The method of claim 7,

the concentration of the alcohol/water mixed solution is 60-99 wt.%, preferably 65-96 wt.%; and/or the presence of a gas in the gas,

the drying time is preferably 4-8 h, and/or,

the drying temperature is 40-65 ℃, and preferably 45-60 ℃.

9. The process of any one of claims 2 to 7, wherein the crude nylon 5X salt is prepared by a process comprising,

and mixing lysine and dibasic acid to form lysine dibasic acid salt, and further converting the lysine dibasic acid salt into nylon 5X salt by using lysine decarboxylase fermentation liquor to obtain a crude nylon 5X salt product.

10. The method as claimed in claim 9, wherein the lysine is lysine fermentation broth, preferably the lysine fermentation broth is selected from lysine fermentation stock, concentrated solution or diluted solution of lysine fermentation stock, sterilized lysine fermentation broth after thallus is removed from lysine fermentation stock, and concentrated solution or diluted solution of sterilized lysine fermentation broth.

Technical Field

The invention belongs to the technical field of industrial crystallization, and particularly relates to a high-purity nylon 5X salt and a preparation method thereof.

Background

Polyamide is commonly called nylon, is an important engineering plastic and textile fiber material, and is widely applied to the fields of machinery, automobiles, electrical appliances, textile equipment, chemical equipment, aviation, metallurgy and the like due to excellent mechanical and other properties. At present, monomers for producing nylon are mainly prepared by a chemical method, raw materials are derived from fossil energy, however, with the increasing shortage of fossil energy and the increasing awareness of human to environmental protection, new chemical materials converted from biomass are developed, and the overall goal of human sustainable development is met. In recent years, the technology of producing long-chain dibasic acid and diamine, which are main raw materials of nylon, by a biological method is gradually industrialized, and the development and production of bio-based nylon become important points of research of various countries in the world.

The bio-based nylon 5X is polymerized by bio-based pentanediamine and bio-based dibasic acid, or the polymerized monomers of the bio-based pentanediamine and the dibasic acid firstly form a precursor of a nylon 5X polymer, namely nylon 5X salt, and then the nylon 5X salt is polymerized. The performance of the nylon polymeric material directly influences the effect of the product, and the performance of the nylon polymeric material is influenced by the quality of the nylon salt, so that the requirement on the quality of the polymer precursor is very high. The quality of nylon salt is influenced by many factors, such as production process, monomer production mode, raw material type and the like. Therefore, the production of nylon salt with qualified quality is more direct and important for ensuring the qualified production of nylon products.

At present, the production method of nylon salt mainly comprises an aqueous solution method and an organic solvent method. The water solution method comprises the steps of taking water as a solvent, dissolving or dispersing dibasic acid and diamine in the water for neutralization reaction, judging a reaction end point according to a pH value to obtain a saturated water solution of nylon salt, and then cooling to separate out the nylon salt from the saturated solution of the nylon salt to obtain a pure nylon salt solid.

In CN201810022432.0, water is adopted for crystallization to obtain the nylon 5X salt, however, the nylon 5X salt has high solubility in water at room temperature, and the yield of the separated nylon 5X salt is very low. In order to precipitate the nylon 5X salt in water, the temperature at which the crystals are precipitated needs to be lowered to a very low temperature to increase the yield, for example, 10 ℃ at freezing point temperature or subzero temperature. However, temperatures below room temperature are often difficult to achieve or energy consumption increases significantly in industrial processes. In addition, the metastable zone of the nylon 5X salt in water is very wide, the temperature reduction process is difficult to control, if seed crystals are not introduced, the process is easy to generate the phenomenon of explosive precipitation nucleation (or called explosive nucleation), so that the solution is suddenly solidified, the stirring is difficult or even impossible, and the refining process cannot be continued.

The organic solvent method is that at a certain temperature, equimolar amounts of dibasic acid and diamine are respectively dissolved in an organic solvent, then mixed together to be completely neutralized, and then separated and dried to obtain the solid nylon salt.

CN201710747693.4 adopts an organic solvent method to prepare nylon 5X salt, adipic acid and pentanediamine are respectively dissolved in ethanol to prepare solutions, neutralization reaction is carried out at 25 ℃ and normal pressure, and a solid nylon 5X salt product is obtained after filtration, washing and drying. The method uses ethanol as a solvent, and the alcohol and the dibasic acid are inevitably subjected to esterification reaction to generate dibasic acid ester, the impurities are difficult to remove from the nylon salt, and the residual dibasic acid ester plays a role of a polymerization inhibitor in the polymerization process of the nylon salt, so that the increase of the molecular weight of the nylon is limited, and the mechanical property of the nylon is influenced.

Because of the defects in the prior art, the process for refining the nylon salt by the one-step method not only has urgent research value, but also has good economic benefit and industrial application value.

Disclosure of Invention

In order to solve the technical problems, the invention provides a high-purity nylon 5X salt and a one-step production process from pentamethylenediamine to the nylon 5X salt, so that a complex and tedious production flow is avoided, the production efficiency is obviously improved, the operation period is shortened, the energy consumption is reduced, and the production cost is saved.

In a first aspect, the invention provides a high-purity nylon 5X salt, wherein the purity of the nylon 5X salt is more than 99.5%.

In some embodiments of the invention, the 50% cumulative volume particle size D of the nylon 5X salt₅₀150 to 350 μm; and/or the presence of a gas in the gas,

the bulk density of the nylon 5X salt is 0.45-0.6 g/cm³。

In some embodiments of the present invention, the nylon 5X salt is obtained by polymerization reaction of a biomass-derived pentamethylene diamine and an aliphatic dibasic acid, preferably, the aliphatic dibasic acid includes, but is not limited to, one of adipic acid, succinic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, and hexadecanedioic acid.

In some embodiments of the present invention, the content of the aliphatic dibasic acid ester in the nylon 5X salt is below 400ppm, preferably below 40 ppm.

In a second aspect, the invention provides a method for purifying the nylon 5X salt, which mainly comprises the following steps:

(1) mixing the crude nylon 5X salt with an alcohol/water mixed solution to obtain a mixture of nylon 5X salt;

(2) heating the mixture of the nylon 5X salt prepared in the step (1) to a temperature T1, preserving heat, cooling, and preserving heat again;

(3) cooling to the temperature T3, and keeping the temperature;

(4) centrifuging, washing and drying for 2-10 hours to obtain nylon 5X salt;

the crude nylon 5X salt is obtained by taking pentanediamine from a biomass source as a raw material and carrying out a polymerization reaction with aliphatic dibasic acid, preferably, the aliphatic dibasic acid comprises one of adipic acid, succinic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid and hexadecanedioic acid without limitation.

In some embodiments of the present invention, in the step (1), the alcohol in the alcohol/water mixed solution may be one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, pentanol or octanol; and/or the presence of a gas in the gas,

the concentration of the alcohol/water mixed solution can be 60-99 wt.%, preferably 65-96 wt.%;

the adoption of the alcohol/water mixed solution is beneficial to avoiding the heterogeneous nucleation problem of the nylon 5X salt solution in the cooling crystallization, reduces the coating amount of impurities in the crystal, increases the formed crystal particles, has more regular crystal form, and is beneficial to the improvement of the product purity.

Preferably, the mass fraction of the crude nylon 5X salt in the mixture of nylon 5X salts is 45-85%, preferably 50-80%.

In some embodiments of the present invention, in the step (2), the temperature T1 is 40-75 ℃, preferably 45-70 ℃; and/or the presence of a gas in the gas,

the heat preservation time U1 is 0.5-2 h, preferably 0.5-1.5 h; and/or the presence of a gas in the gas,

the cooling rate is 2-15 min/DEG C, preferably 4-9 min/DEG C; and/or the presence of a gas in the gas,

the temperature T2 after temperature reduction is different according to the used solvent, the concentration of the solvent and the proportion of the solvent, and the temperature T2 is also different; in some preferred embodiments of the present invention, the temperature T2 is 40-65 ℃, preferably 45-60 ℃;

the time U2 for heat preservation again is 0.5-2.5 h, preferably 1-1.5 h; .

In some embodiments of the present invention, in the step (3), the temperature T3 is 10 to 35 ℃, preferably 15 to 30 ℃, and more preferably 20 to 30 ℃; and/or the presence of a gas in the gas,

the cooling rate is 2-15 min/DEG C, preferably 4-9 min/DEG C; and/or the presence of a gas in the gas,

the time U3 is 0.5-2 h, preferably 0.5-1 h.

In some embodiments of the present invention, in step (4),

the washing is carried out by leaching in alcohol or alcohol/water mixed solution at ambient temperature;

the alcohol can be one or more of methanol, ethanol, n-propanol, isopropanol, butanol, 2-butanol, pentanol or octanol; and/or the presence of a gas in the gas,

the alcohol in the alcohol/water mixed solution can be one or more of methanol, ethanol, n-propanol, isopropanol, butanol, 2-butanol, pentanol or octanol; and/or the presence of a gas in the gas,

the concentration of the alcohol/water mixed solution can be 60-99 wt.%, preferably 65-96 wt.%; and/or the presence of a gas in the gas,

the drying time is preferably 4-8 h, and/or,

the drying temperature is 40-65 ℃, and preferably 45-60 ℃.

The filter cake is leached by adopting the alcohol/water mixed solution with the correct concentration, and the residual crystallization mother liquor in the filter cake can be replaced. Successfully solves the technical problem that the crystallization mother liquor remains in the filter cake and the polyamide 5X product turns yellow in the prior art. And the boiling point of the alcohol/water mixed solution is low, the alcohol/water mixed solution is easy to remove in the drying process, the residual amount of the solvent in the product is low, the purity of the nylon salt product is greatly improved, the energy consumption is reduced, and the production cost is reduced.

In some embodiments of the invention, the ethanol solvent and the wash solution produced during the refining process are completely recovered and recycled. Saves raw materials and water resources, reduces production cost, reduces the load of wastewater treatment, and is beneficial to environmental protection.

The nylon 5X salt crude product can be nylon 5X salt crude products from any source. In some embodiments of the present invention, the crude nylon 5X salt is a crude nylon 5X salt prepared by mixing a dibasic acid and a pentamethylene diamine which are prepared separately and have high quality; in some embodiments of the present invention, the crude nylon 5X salt is obtained by mixing lysine with dibasic acid to form lysine dibasic acid salt, and further converting the lysine dibasic acid salt into nylon 5X salt by using lysine decarboxylase fermentation broth; preferably, the lysine is lysine fermentation liquor.

In some preferred embodiments of the invention, the crude nylon 5X salt is prepared by the following method,

and mixing the lysine fermentation liquor with dibasic acid to form lysine dibasic acid salt feed liquid, further converting the lysine dibasic acid salt feed liquid into nylon 5X salt feed liquid by using lysine decarboxylase fermentation liquor, then performing decolorization filtration on the nylon 5X salt feed liquid, and concentrating and evaporating the obtained nylon 5X salt water solution to dryness to obtain a crude nylon 5X salt product.

In some preferred embodiments of the present invention, the lysine fermentation broth is selected from a lysine fermentation stock solution, a concentrated solution or a diluted solution of the lysine fermentation stock solution, a sterilized lysine fermentation broth after bacteria are removed from the lysine fermentation stock solution, and a concentrated solution or a diluted solution of the sterilized lysine fermentation broth.

The lysine fermentation broths described in the present application can be prepared by the prior art, for example, reference can be made to the following documents: "design and optimize the L-lysine fermentation process based on robustness", Sun Yuhua, etc., biotechnological communication, 2007, Vol 1 of 18; "lysine fermentation industrialization research-selection and control mode of nitrogen source concentration in lysine fed-batch fermentation", yihongbo et al, food and fermentation industry, 1999 12 months; "research on improving fermentation level of L-lysine by gradient temperature method", is cheap, few and outstanding, food industry science and technology, stage 8 of 2012; and optimization of fermentation conditions of lysine shake flasks, Yi Hon Bo et al, university of Wuxi California, 1999 6 months. In addition, reference may be made to the methods for producing a lysine fermentation stock described in patent documents CN201210009446.1, CN201210009450.8, CN201210009366.6, and CN 201210132764.7.

When the lysine fermentation liquor is selected from lysine fermentation stock solution, concentrated solution or diluted solution of the lysine fermentation stock solution, filtering and centrifuging the lysine fermentation liquor to remove thalli in the lysine fermentation liquor, and then adding dibasic acid to form lysine dibasic acid salt feed liquid;

the filtration is selected from one or more of plate-frame filtration, ceramic membrane filtration, bag filtration, laminated filtration, metal titanium rod filtration and the like.

The dibasic acid is aliphatic dibasic acid, and non-limiting examples of the dibasic acid include adipic acid, succinic acid, sebacic acid, undecanoic acid and dodecanoic acid.

The decolorization is activated carbon decolorization, preferably, the using amount of the activated carbon is 0.1-5 wt% of the total amount of lysine in the lysine fermentation liquor, the temperature in the decolorization process is 30-70 ℃, and the time is 30-90 minutes.

In a third aspect, the present invention provides a method of producing nylon, the method comprising polymerising a nylon salt produced by any one of the above methods.

Compared with the prior art, the invention has the following advantages:

(1) the purity of the high-purity nylon 5X salt provided by the invention can reach more than 99.5%, and the nylon 5X salt can be directly used for polymerization.

(2) The nylon 5X salt product provided by the invention has the advantages of large particles, uniform particle size distribution, high bulk density, good granularity and good fluidity, and solves the problem of easy caking in the storage and transportation processes.

(3) The alcohol-water solution crystallization method of the nylon salt provided by the invention solves the problem of low yield of nylon salt crystallization products by a water solution method, and the content of nylon 5X salt in crystallization mother liquor is very low. And the alcohol-water solvent system is easier to control the crystallization process, thereby avoiding the nucleation of the explosive precipitation and improving the efficiency of the crystallization process.

(4) The method for producing the nylon salt by the one-step method by coupling the production processes of the pentamethylene diamine and the nylon salt saves the complicated process flow, reduces the equipment investment and saves the production cost.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The term "about" represents the degree of inherent uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term "value" as used herein means a value that can vary from the stated reference value to some extent without resulting in a change in the basic function of the subject matter being reviewed.

1. Evaluation method and apparatus of particle size:

50% cumulative volume particle size D according to the invention₅₀Are typical amounts used to indicate particle size distribution.

The 50% cumulative volume particle size D₅₀Is a value for particle size such that 50 vol.% of the crystals have a size less than this value.

Particle size was evaluated using a Focused Beam Reflectometry (FBRM) instrument, model Particletrack G400, available from Mettler Tolydo corporation. D50 data were obtained by FBRM by measuring the particle chord length distribution statistics in a certain area of the system by laser reflection.

2. Bulk density of the particles:

measured according to USP method II (page 1914).

3. The nylon color detection method comprises the following steps:

according to the GB-T2409-1980 standard, the kit adopts a KONICA MINOLTA CM-3600A device for detection.

4. The method and the equipment for testing the content of the dibasic acid ester are as follows:

carrying out gas chromatography detection (normalization method) on a sample after pretreatment, wherein the chromatographic conditions are as follows: a chromatographic column: supelco SPB-5030m 0.53mm 0.5 μm (cat 54983).

Gas chromatograph (Shimadzu, GC-2014).

The method comprises the following steps: the initial temperature is 100 ℃, the temperature is raised to 230 ℃ at the speed of 15 ℃/min, and the temperature is kept for 2 min. The carrier gas is hydrogen, the injection port temperature is 280 ℃, the FID temperature is 280 ℃, and the injection amount is 4 mu L.

The purity of the adipic acid is 99.0 percent, and the adipic acid is purchased from chemical reagents of national drug group, Inc.; the purity of the sebacic acid is 99.5 percent, and the sebacic acid is purchased from Heizhua chemical Co., Ltd; dodecanedioic acid has a purity of 99.8% and is available from Kaiser (Jinxiang) biomaterials Co.

The purity of the raw material pentamethylene diamine in the comparative example was 98.0%, and was purchased from Kaiser (Jinxiang) biomaterials Co., Ltd.

Preparation example 1

According to CN201410004636.3 and CN201810022432.0, lysine fermentation liquor passes through a ceramic membrane to obtain pure lysine collection liquid, adipic acid and lysine are used for reacting to generate a lysine adipate solution after deamination, and the pH of the reaction solution is controlled to be 5-7. Adding the cultured lysine decarboxylase fermentation liquor into the treated lysine adipate feed liquor, wherein the addition amount of the lysine decarboxylase fermentation liquor is 8 wt% of the lysine adipate. The pH value in the conversion process is controlled to be 7.1, the mixture is converted into an aqueous solution of the pentanediamine adipate by adding adipic acid solid, and the aqueous solution of the pentanediamine adipate is filtered by a ceramic membrane to obtain a nylon 56 salt feed liquid. And then adding the nylon 56 salt stock solution into activated carbon which accounts for 3 wt.% of the total lysine content in the lysine fermentation liquor for decolorization, filtering after 60 minutes of decolorization at 50 ℃, and concentrating to obtain a crude nylon 56 salt product.

By referring to the preparation method, adipic acid is replaced by sebacic acid and dodecanedioic acid to prepare crude nylon 510 salt and crude nylon 512 salt.

Preparation example 2

Referring to CN201410790873.7, crude nylon 56 salt was prepared from commercially available 1, 5-pentanediamine and adipic acid.