CN102344388B - Polypropylene beta nucleating agent and its preparation method and use - Google Patents

Abstract

The invention discloses a polypropylene beta nucleating agent, which is N, N'-dicyclohexyl-1,5-diamino-2,6-naphthalene dicarboxamide. The invention also provides a preparation method of the β-nucleating agent, which is prepared by using 10-30 g of naphthalene dicarboxylic acid as a raw material through a series of reactions. The β-nucleating agent disclosed in the present invention is characterized in that it has high selectivity and nucleation efficiency, can induce polypropylene to produce a high content of β-crystals, can increase the crystallization temperature of polypropylene to a large extent, and has a structure with The reactive -NH ₂ functional group can carry out some specific reactions with other substances, further expanding the function of the β-nucleating agent.

Description

A kind of polypropylene beta nucleating agent and its preparation method and application

technical field

The invention relates to a beta nucleating agent, in particular to a beta nucleating agent for polypropylene, and also relates to a preparation method and application of the beta nucleating agent.

Background technique

Polypropylene (PP) is one of the five general-purpose plastics. It has good processing, mechanical and chemical resistance properties, and is widely used in household appliances, automobiles, electronics, packaging and building materials and furniture. However, PP also has many shortcomings, especially poor toughness and high low-temperature brittleness, which limit the further expansion of PP application fields. Therefore, the modification of PP has important theoretical significance and broad commercial space. Polypropylene is a polycrystalline polymer with crystal forms such as α, β, γ, δ and pseudo-hexagonal crystals, among which the β crystal form has a low density and a loose structure, and is prone to plastic deformation when subjected to external forces, forming microsilver Grains or micropores are conducive to energy dissipation and thus improve the toughness of PP. Therefore, during the molding process of PP, trying to induce the formation of a large number of β-crystals in the system can achieve the purpose of toughening PP.

β-nucleating agent is a class of substances that can induce PP to produce a high content of β-crystals. β-nucleating agents are divided into two categories: organic and inorganic. Organics mainly include fused ring aromatic hydrocarbons (dyes), amides, organic acids and salts. Inorganic products mainly include inorganic salts, inorganic oxides and some low melting point metal powders. The earliest β-nucleating agents used in commercial production were aromatic amine nucleating agents. This type of β-nucleating agent was patented by the Japanese New Physical and Chemical Company in 1992 and commercialized in 1998. Common aromatic amine nucleating agents mainly contain two types: 2,6-phthalic acid cyclohexylamide (DCTH) [EP 0557721] and N, N'-dicyclohexyl-2,6-naphthalene dicarboxamide (DCNDCA , trade name NJStar, NJS or NU-100) [EP 0865909A1]. In recent years, my country's Shanxi Research Institute of Chemical Industry has developed β-nucleating agents with trade names TMB-4 and TMB-5, both of which are substituted aromatic amides, which also belong to this category. CN85100465 and CN101605749A etc. disclose a series of β-nucleating agents (especially pimelic acid and calcium stearate) composed of salts of dibasic carboxylic acids and group IIA metal elements in the periodic table. CN00117339 discloses a rare earth organic complex WBG as a beta nucleating agent for polypropylene.

In order to reduce the cost and improve the nucleation efficiency of the β-nucleating agent, CN101157771B and CN101580601A disclose the method of firstly loading the dicarboxylic acid, and then preparing the β-nucleating agent. CN101619143B discloses a fiber-loaded β-nucleating agent, which can use the reinforcing function of the fiber material and the good toughness of the β-crystal, so that the prepared polypropylene composite material can obviously improve the toughness and ductility of the material without reducing the strength and modulus sex. The above supported β-nucleating agents are related to the extended application of β-nucleating agents of organic acids and salts. For other types of β-nucleating agents, due to the lack of reactive active groups in their structures, their further modification applications are limited.

Contents of the invention

The object of the present invention is to provide a β-nucleating agent with higher selectivity and higher nucleation efficiency.

The β-nucleating agent of the present invention is N, N'-dicyclohexyl-1,5-diamino-2,6-naphthalene dicarboxamide. Its structural formula is as follows:

The β-nucleating agent can increase the β-crystal content of the polypropylene and increase the crystallization temperature of the polypropylene, thereby achieving the purpose of improving the properties of the polypropylene. At the same time, its structure has a reactive -NH ₂ functional group, which can perform certain specific reactions with other substances, further expanding the function of the β-nucleating agent.

Another object of the present invention is to provide a preparation method of the β-nucleating agent.

The preparation method of β nucleating agent provided by the invention is as follows:

(1) Add 10-30g of naphthalene dicarboxylic acid to 100-300ml of strong oxidizing acid, heat and stir the mixture, control the reaction temperature at 50-100℃, and the reaction time for 10-24h, then filter and dry the reaction solution Obtain intermediate product NA-1;

(2) Dissolve 1-5g of NA-1 in 10-30ml of organic solvent, add 0-0.1g of catalyst, and then add the acid chloride agent thionyl chloride with a molar ratio of 1:1-5:1 to NA-1 , control the reaction temperature at 50-100°C, and the reaction time is 10-24h, then filter and dry the reaction solution to obtain the intermediate product NA-2;

(3) Add cyclohexylamine and triethylamine with a molar ratio of 1:1 to 3:1 into 10 to 50ml of organic solvent, dissolve 1 to 5g of NA-2 in the same organic solvent to form a 5 to 20ml solution, Mix the two solutions, stir at 5-50°C for 1-5 hours, and then filter and dry the reaction solution to obtain an intermediate product that is NA-3;

(4) Add 0.5-1.5g of catalyst to 50ml organic solution containing 1-5g NA-3, stir at 20-50°C for 10-24h, and then filter and wash the mixture with 300-500ml dimethyl sulfoxide After drying, a tan solid is finally obtained, which is the target product NA, that is, the polypropylene β-nucleating agent.

A further solution is: in step (1) of the above preparation method, the strong oxidizing acid is concentrated nitric acid, and the reaction solution needs to be diluted in ice water before suction filtration.

A further solution is: in step (2) of the above preparation method, the organic solvent is 1,2-dichloroethane, and the catalyst is pyridine, dimethylformamide DMF or benzyltriethyl ammonium chloride.

A further solution is: step (3) in the above preparation method, the organic solvent is dichloromethane, and cyclohexylamine and triethylamine are added to an appropriate amount of dichloromethane, and then the dissolved NA-2 The dichloromethane solution was mixed with it, stirred at 5-50°C for 1-5h, and then dried by suction filtration.

A further solution is: in step (4) of the above preparation method, the organic solvent is methanol or acetone, and the catalyst is Fe/HCl, Sn/HCl or supported metal Pd catalyst Pd/C.

Another object of the present invention is to provide the use of the β-nucleating agent.

The beta nucleating agent is used to modify polypropylene.

A further solution is: when modifying polypropylene, the amount of β-nucleating agent used is 0.01-5% of the mass of polypropylene.

The present invention has the following advantages:

1. The provided β-nucleating agent has high selectivity and nucleation efficiency. After blending with polypropylene resin, it can induce polypropylene to produce a high content of β-crystals, and at the same time, it can greatly increase the crystallization temperature of polypropylene. After adding the β-nucleating agent with a mass fraction of 0.1% to polypropylene, the crystallization temperature can be increased by about 10°C, and the β-crystal content is as high as 94% compared with the unadded polypropylene material. Compared with pure polypropylene, its crystallization temperature and β-crystal content have been significantly increased.

2. Compared with other β nucleating agents, such as widely used commercial rare earth nucleating agent WBG and amide nucleating agent TMB, the provided amide polypropylene β nucleating agent, N, N'- Dicyclohexyl-1,5-diamino-2,6-naphthalene dicarboxamide has higher selectivity and nucleation efficiency, and induces more β crystals at the same content.

3. The structure of the provided β-nucleating agent has a reactive -NH ₂ functional group, which can carry out certain specific reactions with other substances to further expand the function of the β-nucleating agent.

Detailed ways

Example 1

For the convenience of illustration, the intermediate products involved in the process of preparing N, N'-dicyclohexyl-1,5-diamino-2,6-naphthalene dicarboxamide (NA) are respectively NA-1, NA-2 and NA -3 said.

At the same time, it should be noted that this embodiment only extracts a certain specific numerical parameter within the range listed in the description for illustration. Those skilled in the art can know that as long as it is within the range listed in the description, the invention can be completed. Specific preparation steps.

The first is the synthesis of NA-1: slowly add 10.5g of 2,2-naphthalene dicarboxylic acid to 100ml of 90% concentrated HNO ₃ and leave it at room temperature for two hours, then heat the mixture to 60°C and stir for 12h. Finally, the mixed solution was poured into ice water and dried by suction to obtain 6.67 g of white solid powder, namely NA-1, with a yield of 45%. Its reaction formula is:

The second is the synthesis of NA-2: 1.78g of NA-1 was dissolved in 18mL of 1,2-dichloroethane, and 0.03g of catalyst benzyltriethylammonium chloride was added. The mixture was heated, then 1.55 g of thionyl chloride (SOCl ₂ ) was added to reflux the mixture for 12 h, then cooled, filtered and washed with diethyl ether to obtain 1.04 g of a yellow solid, namely NA-2, with a yield of 83%. Its reaction formula is:

Then the synthesis of NA-3: 1.45g of cyclohexylamine was added into 30ml of dichloromethane (CH ₂ Cl ₂ ), and 30ml of triethylamine (Et ₃ N) was dissolved at the same time. Then 10mL CH ₂ Cl ₂ solution containing 2.4g NA-2 was added to the previous mixture, stirred at room temperature for 1h, and then the precipitate was filtered and dried to obtain 2.87g white solid which was NA-3, the yield was 87.5%. Its reaction formula is:

Further synthesis of NA: Add 1.23g Pd/C catalyst to 50mL MeOH solution containing 4.1g NA-3, stir the mixture at 40°C for 12h, then filter the mixture with 500mL dimethyl sulfoxide (DMSO) After washing, 2.4 g of tan solid was finally obtained, which was NA, and the yield was 68%. Its reaction formula is:

Finally, the obtained product NA was used as a β-nucleating agent and dried polypropylene (brand T30S, melt flow rate 2.3g/10min, density 0.92g/cm ³ ) in the ratio of 0.05%:99.95% by mass fraction. The moment rheometer XSS-300 was used for blending and banburying. The experimental temperature was 200°C, the rotational speed was 50r/min, and the time was 5min to obtain a polypropylene sample containing β-nucleating agent NA. Take 5 ~ 10mg to carry out DSC test on differential scanning calorimeter TA Q20, measure its crystallization temperature, the results are shown in Table 1; in addition, the polypropylene sample obtained by taking an appropriate amount of torque is pressed under a precision automatic tablet press Thin slices with a thickness of 0.5 mm were tested by XRD with an X-ray diffractometer X'Pert Pro MPD DY1291 to measure the β crystal content K _β . The test results are shown in Table 1.

Example 2

The mass fraction ratio of the beta nucleating agent prepared by the same method in Example 1 and polypropylene is 0.1%:99.9%, other processing conditions and procedures are all constant, survey its crystallization temperature and beta crystal content, the results are as shown in table 1 Show.

Example 3

The mass fraction ratio of the beta nucleating agent prepared by the same method in Example 1 and polypropylene is 0.3%:99.7%, other processing conditions and procedures are all constant, survey its crystallization temperature and beta crystal content, the results are as shown in table 1 Show.

Example 4

The mass fraction ratio of the beta nucleating agent prepared by the same method in Example 1 and polypropylene is 0.5%:99.5%, other processing conditions and procedures are all constant, survey its crystallization temperature and beta crystal content, the results are as shown in table 1 Show.

In order to understand the characteristics of the specific application of the polypropylene beta nucleating agent N, N'-dicyclohexyl-1,5-diamino-2,6-naphthalene dicarboxamide synthesized and prepared by the present invention in polypropylene materials, the Two widely used high-efficiency polypropylene β-nucleating agents (commercial rare earth nucleating agent WBG-Ⅱ, produced by Guangdong Weilinna Functional Materials Co., Ltd.; commercial amide nucleating agent TMB, produced by Shanxi Chemical Research Institute ) for comparison, other processing conditions and procedures are the same as in Example 1, comparative examples a1, a2, a3 and a4 correspond to polypropylene samples with WBG-II mass fractions of 0.05%, 0.1%, 0.3% and 0.5% respectively; b1, b2, b3 and b4 correspond to polypropylene samples with TMB mass fractions of 0.05%, 0.1%, 0.3% and 0.5%, respectively. In addition, the pure polypropylene T30S was used as a reference to carry out the above test according to the same processing procedure.

The crystallization temperature data of each test sample of table 1

Note: The relative content K _β of the β crystal form in the sample is calculated using the Turner-Jones formula.

As can be seen from Table 1, under the same content of β nucleating agent, after modifying polypropylene with the β nucleating agent obtained in the present invention, the β crystal content and crystallization temperature in the sample are higher, that is, the present invention obtains The selectivity and high nucleation efficiency of the β-nucleating agent are relatively higher than the other two commercial β-nucleating agents WBG-II and TMB, and it is an excellent polypropylene β-nucleating agent.

Claims (7)

1. a polypropylene beta nucleating agent, characterized in that the structural formula of the polypropylene beta nucleating agent is: 2. the preparation method of polypropylene beta nucleating agent described in claim 1 is characterized in that, comprises the following steps: (1) Add 10-30g of naphthalene dicarboxylic acid to 100-300ml of strong oxidizing acid, heat and stir the mixture, control the reaction temperature at 50-100℃, and the reaction time for 10-24h, then filter and dry the reaction solution Obtain intermediate product NA-1, the structural formula of NA-1 is: (2) Dissolve 1-5g of NA-1 in 10-30ml of organic solvent, add 0-0.1g of catalyst, and then add the acid chloride agent thionyl chloride with a molar ratio of 1:1-5:1 to NA-1 , control the reaction temperature at 50-100°C, and the reaction time is 10-24 hours, then filter and dry the reaction solution to obtain the intermediate product NA-2, the structural formula of NA-2 is: (3) Add cyclohexylamine and triethylamine with a molar ratio of 1:1 to 3:1 to 10 to 50ml of organic solvent, and then mix 5 to 20ml of dichloromethane solution with 1 to 5g of NA-2 Mix and stir at 5-50°C for 1-5 hours, then filter and dry the reaction solution to obtain an intermediate product that is NA-3, and the structural formula of NA-3 is: (4) Add 0.5-1.5g of catalyst to 50ml organic solution containing 1-5g NA-3, stir at 20-50°C for 10-24h, and then filter and wash the mixture with 300-500ml dimethyl sulfoxide Dry, and finally obtain a tan solid which is the target product polypropylene β-nucleating agent; In step (1), the strong oxidizing acid is concentrated nitric acid, and the reaction solution needs to be diluted in ice water before suction filtration. 3. The preparation method of polypropylene beta nucleating agent according to claim 2, characterized in that: the organic solvent used in step (2) is 1,2-dichloroethane, and the catalyst used is pyridine, dimethyl formamide DMF or benzyltriethylammonium chloride. 4. The preparation method of the polypropylene β-nucleating agent according to claim 2, characterized in that: the organic solvent used in step (3) is dichloromethane. 5. The preparation method of polypropylene beta nucleating agent according to claim 2, characterized in that: the organic solvent used in step (4) is methanol or acetone, and the catalyst used is Fe/HCl, Sn/HCl or supported Metal Pd Catalyst Pd/C. 6. The application of the polypropylene beta nucleating agent of claim 1 in modified polypropylene. 7. The application of the polypropylene beta nucleating agent in modified polypropylene according to claim 6, characterized in that the amount of the polypropylene beta nucleating agent is 0.01 to 5% of the polypropylene mass.