CN113248703B

CN113248703B - Cuprous iodide suspension and preparation method thereof

Info

Publication number: CN113248703B
Application number: CN202110654744.5A
Authority: CN
Inventors: 叶楚祥
Original assignee: Shanghai Pugong Material Technology Co ltd
Current assignee: Shanghai Pugong Material Technology Co ltd
Priority date: 2021-06-11
Filing date: 2021-06-11
Publication date: 2022-07-01
Anticipated expiration: 2041-06-11
Also published as: CN113248703A

Abstract

The invention relates to the technical field of nylon fabric preparation, in particular to cuprous iodide suspension and a preparation method thereof, wherein the suspension comprises the following components in parts by weight: 1.5% -4.5% of cuprous iodide; 1% of nano montmorillonite; 0.2 percent of cuprous iodide surface treating agent; 94.3 to 97.3 percent of distilled water. The cuprous iodide suspension and the potassium bromide solution are added into the PA66 batch polymerization reaction together, so that the application of the cuprous iodide and potassium bromide system in the preparation of a PA66 batch method is realized.

Description

Cuprous iodide suspension and preparation method thereof

Technical Field

The invention relates to the technical field of nylon fabric preparation, in particular to cuprous iodide suspension and a preparation method thereof.

Background

PA66 (polyhexamethylene adipamide, commonly known as nylon 66) is prepared by polycondensation of adipic acid and hexamethylene diamine, but in the actual industrial polymerization process, adipic acid and hexamethylene diamine are generally prepared into 66 salt (adipic acid adipamide), and then the 66 salt is subjected to dehydration polycondensation reaction to generate amide bonds in the dehydration process, so that linear macromolecules are formed. There are two current polymerization modes of PA 66: batch processes and continuous processes.

PA66 with heat-resistant stability is a six-membered ring chelate of copper/iodine or copper/bromine formed in the polymerization process of PA66, and the chelate has the function of a heat-resistant protective layer, so that the PA66 slice can be used for a long time in a temperature environment of 180 ℃. The PA66 polymer having thermal stability is theoretically provided with a heat-resistant protective layer having a copper atom content of 65-130PPM and forming a six-membered ring halogen chelate compound centered on copper ions.

At present, air bag yarns required by common automobile safety air bags and cords required by automobile tires are all made of PA66 slices with heat-resistant and stable characteristics through spinning, and the higher the strength of the yarns is, the better the heat resistance is, and the better the safety of the automobiles is.

Currently, the mainstream adding mode of domestic PA66 polymerization manufacturers (mainly including the Shenma group and the Huafeng group) is as follows: 1) the batch process employs a copper acetate and potassium iodide system, which is the copper/iodine system described above. As is known, the dehydration and polycondensation of 66 salts into PA66 belongs to a water phase reaction, copper acetate, potassium iodide and potassium bromide can be dissolved in water, cuprous iodide is not dissolved in water, the copper acetate and potassium iodide adopted in the batch method utilize the characteristic that two components can be dissolved in water, but from the practical application effect, the cuprous iodide and potassium bromide system is superior to the copper acetate and potassium iodide system for three reasons: 1) copper acetate can generate acetate after being dissolved in water, the acetate can play a role in inhibiting polymerization in the process of 66 salt polymerization and directly influences the relative viscosity and molecular weight distribution of a PA66 melt, 2) a copper acetate and potassium iodide system can improve the shear viscosity of a PA66 melt and reduce the transparency of a PA66 slice, and 3) a copper acetate and potassium iodide system can influence the crystallinity of a PA66 slice, so that the spinning strength of a PA66 slice can be influenced, the strength of an air sac yarn and a cord yarn spun by a PA66 slice with heat-resistant and stable characteristics obtained by domestic intermittent polymerization is about 9.0D/g (gram denier), and the air sac yarn and the cord yarn belong to middle-low level.

In view of the above-mentioned drawbacks, and based on the fact that foreign manufacturers (e.g., amada americana, asahi chemical industry, etc.) have already abandoned the copper acetate and potassium iodide system and have adopted the cuprous iodide and potassium bromide system, it is imperative to solve the problem of preparing a suspension of cuprous iodide in order to apply the cuprous iodide and potassium bromide system to the batch process as soon as possible.

Disclosure of Invention

The invention aims to solve the defects of the prior art and provide a cuprous iodide suspension which is added in the batch polymerization of PA66 and has the characteristic of heat resistance stability.

In order to achieve the purpose, a cuprous iodide suspension is designed, and comprises the following components in parts by weight:

the invention also has the following preferable technical scheme:

further, the cuprous iodide surface treatment agent comprises OP wax, S wax and E wax.

Further, the cuprous iodide suspension was added to the batch polymerization of PA66 together with a potassium bromide solution.

In another aspect of the present invention, a method for preparing a cuprous iodide suspension is also provided, comprising the steps of:

s1, putting the E wax and the cuprous iodide into a high-speed stirrer, heating to 60 ℃, stirring, and cooling to room temperature;

and S2, putting the weighed distilled water and the nano montmorillonite into a grinder to grind, and pouring the mixture of the E wax and the cuprous iodide into the grinder to grind continuously to obtain the cuprous iodide suspension.

Advantageous effects of the invention

The cuprous iodide suspension and the preparation method thereof provided by the invention have the advantages that: provides a cuprous iodide suspension, and realizes the application of a cuprous iodide and potassium bromide system in the preparation of PA66 batch process.

Detailed Description

The technical solutions adopted by the present invention are further described below by examples to help those skilled in the art to better understand the technical solutions adopted by the present invention.

The invention provides a cuprous iodide suspension which comprises the following components in percentage by weight:

wherein, the cuprous iodide is analytically pure, has a particle size of more than 500 meshes, preferably 600-700 meshes, and is prepared by Shanghai national drug group;

the nano montmorillonite is subjected to cationic surface treatment, the particle size is less than 100nm, the preferred particle size is 25nm, and the model OK-NT Zhejiang Feng Sai New Material Co., Ltd is provided;

the cuprous iodide surface treating agent can be OP wax, S wax and E wax, preferably E wax, and the type is LICOWAX (melting point 53 ℃) and Germany Clariant company;

the water can be deionized water, tap water with H being 7 or distilled water, preferably distilled water, and is prepared by self.

The suspension was added to a batch polymerization of PA66 together with a potassium bromide solution.

The method has the advantages that a joint development agreement is achieved with PA66 polymerization SM enterprises with the largest scale in China, batch process production lines are provided by the SM enterprises to implement pilot-scale experiments, the volume of a polycondensation kettle for batch production provided by the SM enterprises is 3 cubic meters, and 2.7 cubic meters can be fed in one time.

Since the batch process polycondensation reactor provided by SM corporation has a volume of 3 cubic meters and an actual charge amount of 2700KG, the present invention sets the charge amount of cuprous iodide suspension to be 1% of the actual charge amount, and the total charge amount of the polycondensation reactor must be maintained constant (liquid level height) in consideration of the safety of the polymerization process, the following examples are provided according to the formulation, as shown in table 1.

TABLE 1

The preparation method of examples 1 to 5 is as follows:

s1, putting the E wax and the cuprous iodide into a high-speed stirrer (2400 rpm), simultaneously heating the temperature of the stirrer to 60 ℃, starting stirring, taking out after stirring for 10 minutes, and cooling to room temperature.

And S2, putting the weighed distilled water and the nano montmorillonite into a grinder, continuously grinding for 30 minutes, pouring the mixture (cuprous iodide and E wax) obtained in the step S1 into the grinder, further grinding for 120 minutes, discharging the slurry after observing that no obvious precipitate exists in the slurry, respectively filling the slurry into a black plastic sealing barrel for later use, and calibrating according to the examples 1-5.

The nano montmorillonite subjected to surface treatment has strong lipophilicity, a very large specific surface area and relatively large universal gravitation, and cuprous iodide has strong lipophilicity after being subjected to E wax surface treatment, so that a plurality of nano montmorillonite particles can adsorb the cuprous iodide particles to form suspended particles under the action of universal gravitation, and thus suspension is formed in water.

Next, the effect of the suspension was verified.

As mentioned above, cuprous iodide and potassium bromide form a six-membered ring halogen chelate with copper ions as the center in the PA66 polymer, in other words, one copper ion forms a six-membered ring chelate with one iodide ion and 5 bromide ions, so that the weight ratio of cuprous iodide to potassium bromide is approximately 1:5 by conversion of the molar ratio, therefore, 5 formulations of potassium bromide are weighed according to the ratio of cuprous iodide provided in table 1, and No. 1, No. 2, No. 3, No. 4, and No. 5 are respectively calibrated, and potassium bromide is prepared into an aqueous solution of potassium bromide (potassium bromide is very soluble in water) at a concentration of 20% for later use.

And (3) simultaneously pouring the suspension prepared in the step (S2) and the prepared potassium bromide solution into a polycondensation kettle of an intermittent method (the total feeding is kept unchanged at 2700 kg), filling nitrogen for protection reaction for 5 hours under the reaction condition of 1atm/280 ℃, and spraying (negative pressure) to discharge when the torque current of a motor reaches a production standard value (the relative viscosity of a melt), so as to obtain the PA66 slice with the heat-resistant and stable characteristics of a copper/bromine system.

2KG of each of five PA66 slices and a commercially available conventional PA66 primary slice (model EPR27, Mars group, comparison sample I) and a commercially representative PA66 slice with heat-resistant and stable characteristics (model 101HSL, manufactured by U.S. DuPont company, comparison sample II) are dried at 90 ℃ for 4 hours, injection molded into standard tensile sample bars by an injection molding machine (injection molding temperature 265 and 280 ℃) according to ASTM standards, 10 sample bars are respectively injection molded for five calibration numbers and two comparison samples, the samples are divided into 2 groups (wherein 1 group is used as blank samples), and the blank samples are placed into a drying vessel to be regarded as a dry state.

The heat resistance evaluation of the PA66 chips has no industry standard nor national standard and can therefore only be evaluated by parallel tests. The heat resistance requirements of various application industries (various automobile host plants, heat insulation strips, spinning and the like) are comprehensively referred, and the following specific settings are set: the sample specimens were placed in a 180 ℃ forced air oven and dried continuously for 168 hours, and then taken out, and the heat resistance effect was evaluated by comparing the tensile strength of the sample specimens with that of the blank specimens according to the ASTM test method.

The test data are as follows:

the tensile strength of the five formulations and the two comparative samples were tested according to ASTM standards, and the test data are shown in table 2.

TABLE 2

As can be seen from the test data of table 2:

after drying for 168 hours, from the viewpoint of the decrease of the tensile strength: examples 1, 2, 3 and 5 are almost consistent, but the difference between example 4 and examples 1, 2, 3 and 5 is very obvious, which shows that the theoretical basis that the PA66 polymer with the heat-resistant and stable characteristic has the copper atom content of 65-130PPM and the copper/bromine system forms a six-membered ring chelate is verified, and the fact that the copper atom content exceeds 130PPM is not significant and the color of the PA66 slice is changed into turquoise or deep blue is proved to affect the color difference and the material cost.

② after drying for 168 hours, the examples 1, 2, 3, 5 are almost consistent with the comparative sample II (DuPont, USA, 101HSL) from the view of the reduction of tensile strength, which shows that the examples 1, 2, 3, 5 have effective heat-resistant effect, and simultaneously prove that the preparation of cuprous iodide suspension is feasible and effective, and can completely replace the currently used copper acetate/potassium iodide system.

③ 168 hours after drying, the comparative sample (EPR27) had almost no heat resistance characteristics and the tensile strength was reduced by almost half, which indicates that the PA66 raw chip without the copper/bromine addition system had no long-term heat resistance.

Recently, SM enterprises adopt the cuprous iodide suspension batch method to polymerize a small batch (25 tons) of PA66 slices with heat-resistant and stable characteristics, and carry out high-speed spinning of air bag yarns through a curtain line production factory under the flag, the strength of the yarns after field test reaches 10.62D/g (gram), the yarns meet the requirement of special yarns (the strength is more than 10.5D/g), the yarns can replace the yarns of the same type as Asahi chemical industry and Dongli Japan, and the heat-resistant effect reaches 97 percent (the strength retention rate of the tested yarns after drying for 168 hours at the temperature of 180 ℃), and the case proves that a copper/bromine system is superior to a true copper/iodine system.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be within the technical scope of the present invention, and the technical solutions and novel concepts according to the present invention should be covered by the scope of the present invention.

Claims

1. The application of the cuprous iodide suspension in the preparation of PA66 is characterized in that the suspension comprises the following components in parts by weight: 1.5 to 4.5 percent of cuprous iodide, 1.0 percent of nano montmorillonite, 0.2 percent of cuprous iodide surface treating agent and 94.3 to 97.3 percent of distilled water; the cuprous iodide surface treatment agent comprises OP wax, S wax and E wax, the nano montmorillonite is subjected to cationic surface treatment before use, and the suspension and a potassium bromide solution are added into a PA66 batch polymerization reaction.

2. Use according to claim 1, wherein the preparation of the suspension of cuprous iodide comprises the following steps: s1, adding the E wax and the cuprous iodide into a high-speed stirrer, heating to 60 ℃, stirring, and cooling to room temperature; s2, putting the weighed distilled water and the nano montmorillonite into a grinder to grind, and pouring the mixture of the E wax and the cuprous iodide into the grinder to grind continuously to obtain the cuprous iodide suspension.