CN119039704B - A method for preparing transparent polypropylene - Google Patents
A method for preparing transparent polypropylene Download PDFInfo
- Publication number
- CN119039704B CN119039704B CN202411398471.2A CN202411398471A CN119039704B CN 119039704 B CN119039704 B CN 119039704B CN 202411398471 A CN202411398471 A CN 202411398471A CN 119039704 B CN119039704 B CN 119039704B
- Authority
- CN
- China
- Prior art keywords
- polypropylene
- dimethylbenzaldehyde
- preparation
- nucleating agent
- formula
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/15—Heterocyclic compounds having oxygen in the ring
- C08K5/156—Heterocyclic compounds having oxygen in the ring having two oxygen atoms in the ring
- C08K5/1565—Five-membered rings
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/10—Esters; Ether-esters
- C08K5/101—Esters; Ether-esters of monocarboxylic acids
- C08K5/103—Esters; Ether-esters of monocarboxylic acids with polyalcohols
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2201/00—Properties
- C08L2201/10—Transparent films; Clear coatings; Transparent materials
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/24—Crystallisation aids
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/54—Improvements relating to the production of bulk chemicals using solvents, e.g. supercritical solvents or ionic liquids
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Heterocyclic Carbon Compounds Containing A Hetero Ring Having Oxygen Or Sulfur (AREA)
Abstract
The application relates to the field of polypropylene materials, in particular to a preparation method of transparent polypropylene. A preparation method of transparent polypropylene comprises the steps of (1) preparing dimethylbenzaldehyde, (2) preparing a transparent nucleating agent, and (3) preparing polypropylene. According to the application, 3, 4-dimethylbenzaldehyde with high purity is not used as a transparent nucleating agent raw material, and the nucleating agent stabilizer is added into a polypropylene processing raw material, so that the production cost of the transparent nucleating agent is reduced, and the finished polypropylene has excellent transparency and no obvious peculiar smell.
Description
Technical Field
The application relates to the field of polypropylene materials, in particular to a preparation method of transparent polypropylene.
Background
Polypropylene (PP) is a commonly used thermoplastic plastic, has excellent chemical stability and electrical insulation, and is light in weight, good in strength and good in heat resistance, so that it is widely used in various fields such as packaging, automobile industry, home appliances, medical appliances, etc. However, polypropylene is a crystalline polymer that forms larger grains when cooled under natural conditions, resulting in a material that exhibits a milky or opaque state that limits the use of polypropylene in certain applications, particularly for those products that require high transparency, such as transparent packaging materials, transparent containers, medical devices, and the like. In order to overcome the limitation, a transparent nucleating agent is added in the processing process of the polypropylene, which is helpful for controlling the crystallization process, so that the polypropylene forms finer grains during crystallization, and the light scattering inside the material is reduced, thereby improving the transparency of the material. The transparent nucleating agent on the market at present is mainly prepared from a third-generation sorbitol product 1,3,2, 4-di (3, 4-dimethyl) benzylidene sorbitol (DMDBS) through aldol condensation reaction of 3, 4-dimethylbenzaldehyde and sorbitol.
However, in the preparation of 3, 4-dimethylbenzaldehyde, isomers are produced, and these byproducts are mainly 3, 5-dimethylbenzaldehyde, 2, 3-dimethylbenzaldehyde, 2, 5-dimethylbenzaldehyde and the like. Since sorbitol acetals obtained by reacting these isomers with sorbitol are easily decomposed, and thus the finished polypropylene may generate an off-flavor, 3, 4-dimethylbenzaldehyde having a purity of 99% or more is generally used in the preparation of DMDBS. However, since these isomers are very similar in nature to 3, 4-dimethylbenzaldehyde, the difficulty in purification by rectification separation is very high, which greatly increases the production cost of DMDBS, thereby limiting further application of DMDBS in the market. And because of the bottleneck of the rectification technology, the complete separation of 3, 4-dimethylbenzaldehyde and isomers thereof is very difficult, which leads to the decomposition of sorbitol acetal generated by the reaction of trace isomers and sorbitol when DMDBS is used as a nucleating agent for preparing polypropylene, thereby releasing aldehydes to generate peculiar smell, and further limiting the market of DMDBS.
Disclosure of Invention
The application provides a preparation method of transparent polypropylene, which aims to solve the problems of high production cost and peculiar smell of the transparent nucleating agent and comprises the steps of (1) preparation of dimethylbenzaldehyde, (2) preparation of the transparent nucleating agent and (3) preparation of polypropylene. According to the application, 3, 4-dimethylbenzaldehyde with the purity of more than 99% is not adopted as a transparent nucleating agent raw material, and a nucleating agent stabilizer is added into a polypropylene processing raw material, so that the production cost of the transparent nucleating agent is reduced, and meanwhile, the prepared polypropylene has less peculiar smell and excellent transparency.
The first aspect of the present application provides a method for preparing transparent polypropylene, comprising the steps of:
The preparation method comprises (1) mixing o-xylene with 1, 2-dichloroethane, adding aluminum trichloride and hydrochloric acid, reacting under carbon monoxide atmosphere, washing the reacted solution, standing for layering, removing the lower solution to obtain upper oily substance, removing solvent in the oily substance to obtain dimethylbenzaldehyde, wherein the dimethylbenzaldehyde comprises 3, 4-dimethylbenzaldehyde and 3, 5-dimethylbenzaldehyde, (2) preparing transparent nucleating agent by mixing dimethylbenzaldehyde with sorbitol, cyclohexane, methanol and p-toluenesulfonic acid, reacting to obtain transparent nucleating agent, (3) preparing polypropylene by mixing the transparent nucleating agent, compound shown in formula I, auxiliary agent and polypropylene matrix resin to obtain polypropylene processing raw material, adding into an extruder, extruding to obtain polypropylene,
I is a kind of
Wherein m, n, x, y in the formula I are each independently integers greater than or equal to 0.
The transparent nucleating agent is prepared by directly reacting the product obtained after the o-xylene reaction with sorbitol, and the dimethylbenzaldehyde is used as a raw material for preparing the transparent nucleating agent without a long-time and precise equipment rectification and purification process, so that the raw material cost of the transparent nucleating agent is greatly reduced, and the production cost of the transparent nucleating agent is reduced. Because 3, 4-dimethylbenzaldehyde isomers exist in the dimethylbenzaldehyde prepared by the method, sorbitol acetal obtained by the reaction of the 3, 4-dimethylbenzaldehyde isomers and sorbitol is easy to attack oxygen atoms on acetal bonds of the sorbitol acetal due to acidity, moisture and other reasons in the reaction environment for preparing polypropylene, so that a hemiacetal intermediate is formed, and finally the acetal bonds are broken, and the acetal bonds are decomposed to release parent aldehyde. Based on the method, the nucleating agent stabilizer shown in the formula I is further added into the raw material for preparing the polypropylene, and the ester group in the nucleating agent stabilizer can consume water molecules and acidic substances in a reaction environment, so that the attack of the nucleating agent stabilizer on the acetal bond of the sorbitol acetal is prevented, the effect of inhibiting the decomposition of the sorbitol acetal is achieved, and the odor of the finished polypropylene is avoided. And the nucleating agent stabilizer shown in the formula I can further combine with trace aldehyde substances possibly existing in a reaction environment due to consumption of water molecules and alcohol substances generated after decomposition of acidic substances, so that peculiar smell brought by the aldehyde substances can be further avoided. In addition, the applicant has unexpectedly found in experiments that compared with the sorbitol acetal transparent nucleating agent generated by the reaction of 3, 4-dimethylbenzaldehyde with purity of more than 99% and sorbitol, the sorbitol acetal transparent nucleating agent generated by the reaction of the dimethylbenzaldehyde and sorbitol which are not subjected to rectification purification can further improve the transparency of polypropylene. Based on this phenomenon, the applicant found through experiments that the anti-reflection effect of the transparent nucleating agent obtained by reacting 3, 5-dimethylbenzaldehyde with sorbitol is better than that of 3, 4-dimethylbenzaldehyde, and that the anti-reflection effect of the transparent nucleating agent obtained by reacting 2, 3-dimethylbenzaldehyde and 2, 5-dimethylbenzaldehyde with sorbitol is close to that of the transparent nucleating agent obtained by reacting 3, 4-dimethylbenzaldehyde. Therefore, the preparation method of the polypropylene reduces the production cost of the transparent nucleating agent, and the finished polypropylene has excellent transparency and no obvious peculiar smell.
In any embodiment, m, n, x, y in formula I is independently 10 or more and 15 or less.
When m, n, x, y in the formula I is respectively and independently more than or equal to 10 and less than or equal to 15, the length of the alkyl chain of the nucleating agent stabilizer is in a proper range, so that the too short alkyl chain can be avoided, the compatibility and the dispersibility between the nucleating agent stabilizer and nonpolar molten polypropylene are reduced, the addition of the nucleating agent stabilizer is not beneficial to the transparency of the polypropylene, the too long alkyl chain can be avoided, the steric effect is obvious, the uniform crystallization of crystal nucleus is not beneficial, and the addition of the nucleating agent stabilizer can also negatively affect the transparency of the polypropylene. M, n, x, y in the formula I is respectively independent and is more than or equal to 10 and less than or equal to 15, so that the nucleating agent stabilizer shown in the formula I has good dispersibility, is easy to form a homogeneous substance with molten PP, and has the effects of inhibiting decomposition of sorbitol acetal, reducing odor of polypropylene, and meanwhile, has no negative effect on transparency of the polypropylene when being used as the nucleating agent stabilizer under the condition of being added in a trace amount.
In any embodiment, in step (3), the compound of formula I is used in an amount of 0.1% to 0.5% based on the mass of the polypropylene matrix resin.
When the dosage of the compound shown in the formula I is in the range, substances such as water, acid and the like in the preparation process of the polypropylene can be consumed, so that aldehyde substances generated by decomposition of unstable sorbitol acetal in the polypropylene can be avoided, trace aldehyde substances possibly existing in the polypropylene can be consumed, and thus obvious smell of a polypropylene finished product can be avoided, excessive amorphous areas in the polypropylene due to excessive dosage can be avoided, the reduction of scattering and refraction of light in the polypropylene is facilitated, and the addition of the nucleating agent stabilizer has no obvious adverse effect on the transparency of the polypropylene.
In any embodiment, the step (1) specifically comprises the steps of mixing o-xylene and 1, 2-dichloroethane, adding aluminum trichloride and hydrochloric acid, carrying out a reaction for 2-3 h at the temperature of minus 10 ℃ to minus 5 ℃ under the carbon monoxide atmosphere, washing the reacted solution with water at the temperature of minus 10 ℃ to minus 5 ℃ to obtain an upper oily substance, standing for layering, removing the lower solution to obtain an upper oily substance, adding imidazole ionic liquid into the oily substance to carry out a catalytic reaction, washing the reacted solution with water at the temperature of minus 10 ℃ to minus 5 ℃ again, standing for layering, removing the lower solution to obtain an upper liquid, and removing a solvent in the liquid to obtain the prepared dimethylbenzaldehyde, wherein the dimethylbenzaldehyde comprises 3, 4-dimethylbenzaldehyde and 3, 5-dimethylbenzaldehyde.
Aldehyde groups on dimethylbenzaldehyde and methyl groups on the benzene ring tend to rearrange in the most stable manner with the lowest energy structure (e.g., 3, 5-dimethylbenzaldehyde) when the charge distribution on the benzene ring is not uniform (e.g., 3, 4-dimethylbenzaldehyde, 2, 3-dimethylbenzaldehyde, 2, 5-dimethylbenzaldehyde, etc.). Based on the discovery that the anti-reflection performance of the transparent nucleating agent obtained by the reaction of 3, 5-dimethylbenzaldehyde and sorbitol on polypropylene is superior to that of other isomers, the applicant further adopts imidazole ionic liquid as a catalyst to catalyze dimethylbenzaldehyde to perform electrophilic rearrangement reaction, so that the content of 3, 5-dimethylbenzaldehyde in dimethylbenzaldehyde is improved, the anti-reflection performance of the transparent nucleating agent on polypropylene is improved, and the haze of polypropylene is further reduced. The imidazole ionic liquid cation can show certain acidity, can be used as a proton donor to promote the conversion of methyl on a benzene ring into electrophilic CH 3 +, and then forms 3, 5-dimethylbenzaldehyde with lower energy and more stable structure through rearrangement with the benzene ring, and the polar environment provided by the imidazole ionic liquid is also favorable for stabilizing electrophilic intermediates. Compared with protonic acid such as hydrochloric acid, the imidazole ionic liquid has the advantages of environmental protection, recycling, structural designability, mildness and the like, can reduce side reaction and improve the selectivity of target products.
In any embodiment, the imidazole-based ionic liquid comprises one or more of 1-methyl-3-butylimidazole bisulfate, 1-butyl-3-methylimidazolium phosphate, and 1-ethyl-3-methyltetrafluoroborate.
Anions of the imidazole ionic liquid such as hydrogen sulfate HSO 4 -, hexafluorophosphate PF 6 ⁻ and tetrafluoroborate BF 4 ⁻ are further beneficial to the conversion of methyl on a benzene ring into electrophilic CH 3 +, so that the imidazole ionic liquid is further beneficial to the catalysis of dimethylbenzaldehyde to generate electrophilic rearrangement reaction, and the selectivity of a target product is improved. The hydrogen sulfate HSO 4 - can dissociate hydrogen ions, so that protons are further provided to promote the conversion of methyl on the benzene ring into electrophilic CH 3 +, the effect of catalyzing dimethylbenzaldehyde to undergo electrophilic rearrangement reaction by the 1-methyl-3-butylimidazole bisulfate is more excellent, and the transparency of polypropylene is further improved.
In any embodiment, the imidazole-based ionic liquid is used in an amount of 0.01% to 0.1% based on the total mass of the oil.
The use amount of the imidazole ionic liquid is in the range, so that the problems that the catalytic electrophilic rearrangement reaction rate is too slow due to too small use amount of the catalyst, the mass ratio of 3, 5-dimethylbenzaldehyde in dimethylbenzaldehyde is too low, the improvement of the transparent performance of polypropylene is not facilitated, the mass ratio of 3, 5-dimethylbenzaldehyde in dimethylbenzaldehyde is too high or the side reaction is too much due to too high use amount of the catalyst or the normal reaction is influenced are avoided, and the addition amount of a nucleating agent stabilizer is controlled in a certain range during the preparation of polypropylene, the decomposition of the nucleating agent stabilizer cannot be inhibited due to the existence of too much unstable sorbitol acetal, and the odor of a polypropylene finished product is generated. The use amount of the imidazole ionic liquid is in the range, and the polypropylene has excellent transparency and does not generate peculiar smell.
In any embodiment, the catalytic reaction is carried out at a temperature of from-10 ℃ to-5 ℃ and for a reaction time of from 1h to 6h.
The temperature of the catalytic reaction is in the range, which is favorable for the electrophilic rearrangement reaction to promote the content of 3, 5-dimethylbenzaldehyde in the prepared dimethylbenzaldehyde, and the reaction time of the catalytic reaction is in the range, which can lead the content of 3, 5-dimethylbenzaldehyde in the prepared dimethylbenzaldehyde to be in a proper range, thereby avoiding too short reaction time, too low content of 3, 5-dimethylbenzaldehyde, being unfavorable for the promotion of the transparency of polypropylene, too long reaction time, too high content of 3, 5-dimethylbenzaldehyde, or side reaction or too much content, reducing the production efficiency and simultaneously leading the polypropylene to generate obvious odor. When the reaction time of the catalytic reaction is within the above range, the transparent nucleating agent gives polypropylene excellent transparency and no significant odor is generated.
In any embodiment, the mass ratio of 3, 5-dimethylbenzaldehyde in the dimethylbenzaldehyde is 8% -40% based on the total mass of the dimethylbenzaldehyde.
When the mass ratio of 3, 5-dimethylbenzaldehyde in dimethylbenzaldehyde is 8% -40%, the transparent nucleating agent prepared from the dimethylbenzaldehyde and sorbitol enables the polypropylene to have excellent transparency, and the nucleating agent stabilizer added into the raw material for preparing the polypropylene effectively inhibits the decomposition of sorbitol acetal, so that the polypropylene has excellent transparency and has no obvious peculiar smell.
In any embodiment, in step (3), the transparent nucleating agent is used in an amount of 0.1% to 0.5% based on the mass of the polypropylene matrix resin.
When the amount of the transparent nucleating agent is in the above range based on the mass of the polypropylene matrix resin, polypropylene has excellent transparency without significant generation of off-flavors.
In any embodiment, in step (3), the auxiliary agent comprises one or more of antioxidant 1010, antioxidant 168, and calcium stearate.
The auxiliary agent is beneficial to improving the mechanical property of polypropylene and prolonging the service life of polypropylene.
In summary, the application has the following beneficial effects:
(1) The transparent nucleating agent is prepared by directly reacting the product obtained after the o-xylene reaction with sorbitol, and the dimethylbenzaldehyde is used as a raw material for preparing the transparent nucleating agent without a long-time and precise equipment rectification and purification process, so that the raw material cost of the transparent nucleating agent is greatly reduced, and the production cost of the transparent nucleating agent is reduced. The nucleating agent stabilizer shown in the formula I is further added into the raw material for preparing the polypropylene, and the ester group in the nucleating agent stabilizer can consume water molecules and acidic substances in a reaction environment, so that the attack of the nucleating agent stabilizer on the acetal bond of the sorbitol acetal is prevented, the effect of inhibiting the decomposition of the sorbitol acetal is achieved, and the obvious peculiar smell of the finished polypropylene is avoided. In addition, the applicant has unexpectedly found in experiments that compared with the sorbitol acetal transparent nucleating agent generated by the reaction of 3, 4-dimethylbenzaldehyde with purity of more than 99% and sorbitol, the sorbitol acetal transparent nucleating agent generated by the reaction of the dimethylbenzaldehyde and sorbitol which are not subjected to rectification purification can further improve the transparency of polypropylene. Therefore, the preparation method of the polypropylene reduces the production cost of the transparent nucleating agent, and the prepared polypropylene has less odor and excellent transparency.
(2) The applicant adopts imidazole ionic liquid as a catalyst to catalyze dimethylbenzaldehyde to generate electrophilic rearrangement reaction, so that the content of 3, 5-dimethylbenzaldehyde in dimethylbenzaldehyde is improved, the anti-reflection performance of a transparent nucleating agent on polypropylene is improved, and the haze of the polypropylene is reduced.
Detailed Description
The present application will be described in further detail with reference to examples and comparative examples.
The following examples, in which the specific conditions are not specified, are conducted under conventional conditions or conditions recommended by the manufacturer, and the raw materials used in the following examples are commercially available from ordinary sources except for the specific descriptions.
Examples
Example 1
A method for preparing polypropylene, comprising the steps of:
(1) Preparation of dimethylbenzaldehyde
Adding 100 parts by weight of o-xylene and 200 parts by weight of 1, 2-dichloroethane, starting a stirrer, pre-cooling the materials in the reaction bottle to-20 ℃ to-10 ℃, sequentially adding 3-4 drops of concentrated hydrochloric acid, 130 parts by weight of anhydrous AlCl 3 serving as a catalyst, introducing nitrogen for displacement, controlling the operation temperature to-10 ℃ to-5 ℃, introducing carbon monoxide, keeping the partial pressure of the carbon monoxide to 1.0Mpa, and starting timing reaction. After 2.5h of reaction, stopping the reaction, closing a carbon monoxide ventilation valve, continuously stirring, pouring the reactants into a prepared ice-salt water flask with the temperature of-10 ℃ to-5 ℃, stirring, placing the flask in a separating funnel, extracting, shaking uniformly, standing for layering, separating lower acid water to obtain an upper oily substance, placing the upper oily substance into a distillation flask, distilling at normal pressure, and removing the solvent to obtain the prepared dimethylbenzaldehyde. Through testing, the mass ratio of 3, 5-dimethylbenzaldehyde in dimethylbenzaldehyde is calculated to be 8%.
(2) Preparation of transparent nucleating agent
400 Parts by mass of cyclohexane and 60 parts by mass of methanol are added, then 30 parts by mass of sorbitol, 50 parts by mass of dimethylbenzaldehyde prepared by the above method and 3 parts by mass of p-toluenesulfonic acid catalyst are sequentially added, the temperature is raised to 70 ℃, aldol condensation reaction is carried out under the nitrogen atmosphere, a mixture of methanol and water is separated by a liquid-liquid separator, the reaction lasts for 6 hours and then is cooled, the temperature is reduced to 50 ℃, alkaline solution is added to neutralize and remove the acid catalyst, the solvent is distilled off, and the transparent nucleating agent product is obtained by filtration and vacuum drying.
(3) Preparation of Polypropylene
Uniformly mixing the prepared transparent nucleating agent, a compound shown in a formula I, an antioxidant 1010, an antioxidant 168, calcium stearate and polypropylene matrix resin in a mass ratio of 2:3:0.5:1:0.5:1000 in a high-speed mixer, and extruding the mixture through a double-screw extruder to obtain polypropylene, wherein m, n, x, y of the compound shown in the formula I is 12, and the compound shown in the formula I is pentaerythritol tetramyristate. Wherein the temperatures of the extruder from the feed inlet to the respective zones of the head are 190 ℃, 200 ℃, 210 ℃, 218 ℃, 210 ℃, 200 and 190 respectively.
The prepared polypropylene is subjected to injection molding in an injection molding machine to prepare standard sample bars required for haze test and odor test, and the temperature from one section of the injection molding machine to the machine head is 200-230 ℃.
Comparative example 1
The polypropylene of comparative example 1 was prepared in a manner substantially similar to that of example 1, except that the transparent nucleating agent of step (2) was prepared using commercially available 3, 4-dimethylbenzaldehyde having a purity of 99% or more.
Comparative example 2
The polypropylene of comparative example 2 was prepared substantially similarly to example 1, except that the polypropylene of step (3) was prepared without the addition of the compound of formula I.
Comparative example 3
The polypropylene of comparative example 3 was prepared in a manner substantially similar to that of example 1, except that the polypropylene of step (3) was prepared without the addition of the compound of formula I, instead of pentaerythritol.
Performance detection
1. Haze degree
A spline having a specification of 50mm by 1mm was prepared and tested according to the ASTM D1003-07 standard.
2. Smell of
Bars with a specification of 50mm x 20mm were prepared using odor test standard VDA270-2018 and placed in 500 ml glass bottles and the caps were closed. The glass bottle and the bottle cap are cleaned before use to keep clean and neutral smell. At ambient temperature, the sample was left for one day and then subjected to odor assessment. The number of the persons participating in the odor evaluation is 5, and the odor evaluation adopts a 6-level evaluation standard:
Level 1 indicates no smell, level 2 indicates smell but no disturbance, level 3 indicates obvious smell but no disturbance, level 4 indicates a disturbed smell, level 5 indicates a strongly disturbed smell, and level 6 indicates intolerance; the evaluation results can be described in half-scale, and the average value is taken as the final odor grade result, and the lower the grade is, the smaller the odor is.
3.3, 5-Dimethylbenzaldehyde content in dimethylbenzaldehyde
The prepared dimethylbenzaldehyde is detected by Gas Chromatography (GC), so that the mass ratio of 3, 5-dimethylbenzaldehyde in the dimethylbenzaldehyde is calculated.
The polypropylene samples of example 1 and comparative examples 1 to 3 were subjected to performance test, and the test results are shown in Table 1, respectively.
TABLE 1 Performance test Table of the polypropylenes of example 1 and comparative examples 1-2
| Sequence number | 3, 5-Dimethylbenzaldehyde mass ratio | Haze/% | Smell of |
| Example 1 | 8% | 8.7 | 1 |
| Comparative example 1 | / | 10.6 | 2 |
| Comparative example 2 | 8% | 9.9 | 5 |
| Comparative example 3 | 8% | 10.3 | 4 |
Referring to Table 1, it can be seen from the comparison of comparative example 1 and comparative examples 1,2, and 3 that the preparation method of the present application greatly reduces the production cost of the transparent nucleating agent, avoids the generation of odor, and further reduces the haze of polypropylene by directly using dimethylbenzaldehyde after reaction and adding the compound represented by formula I. Comparative example 1 the transparent nucleating agent was prepared using 3, 4-dimethylbenzaldehyde having a purity of 99% or more, which was relatively high in cost, as a raw material for the preparation of polypropylene, and since the raw material may contain trace isomers which could not be completely separated, the polypropylene of comparative example 1 was odorous without the addition of the compound represented by formula I. In comparative example 2, the transparent nucleating agent is prepared by directly taking the reacted dimethylbenzaldehyde as a raw material, but under the condition that the compound shown in the formula I is not added for inhibiting the decomposition of sorbitol acetal and removing aldehyde substances, the polypropylene has strong peculiar smell, and is not beneficial to the application of polypropylene products in the fields of foods, cosmetics, medicines and the like. In comparative example 3, the transparent nucleating agent is prepared by directly taking the reacted dimethylbenzaldehyde as a raw material, and pentaerythritol is added into the raw material for preparing polypropylene, so that the effect is weak and the transparency of the polypropylene is negatively affected although the pentaerythritol plays a role in inhibiting odor to a certain extent.
Examples 2 to 5
The polypropylene of examples 2-5 was prepared in a manner substantially similar to that of example 1, except that the structure of the compound of formula I added in step (3) was changed, as follows:
Example 2 the compound m, n, x, y of formula I was 10 and the compound of formula I was pentaerythritol tetralaurate;
example 3 the compound m, n, x, y of formula I was 14 and the compound of formula I was pentaerythritol tetrapalmitate;
Example 4 the compound m, n, x, y of formula I is pentaerythritol tetra-n-heptanoate;
Example 5 the compound of formula I m, n, x, y is 16 and the compound of formula I is pentaerythritol tetrastearate;
The polypropylene samples of examples 2-5 were subjected to performance testing and the test results are shown in Table 2, respectively.
Table 2 table of properties of polypropylene of example 1 and examples 2-5
| Sequence number | 3, 5-Dimethylbenzaldehyde mass ratio | Haze/% | Smell of |
| Example 1 | 8% | 8.7 | 1 |
| Example 2 | 8% | 9.2 | 1 |
| Example 3 | 8% | 9.7 | 1 |
| Example 4 | 8% | 9.9 | 1 |
| Example 5 | 8% | 10.4 | 1 |
Referring to Table 2, it can be seen from a comparison of examples 1 to 3 and examples 4 to 5 that m, n, x, y of the compound of formula I is advantageous to further reduce the haze of polypropylene when it is 10 or less and 15 or less, because it is possible that when the length of the carbon chain of the compound of formula I linked to the ester group is in a proper range, it is easy to form a homogeneous phase with the molten PP, and it does not affect the crystallization of the polypropylene, thereby avoiding odor generation of polypropylene and at the same time, it is excellent in transparency. When m, n, x, y of the compound shown in the formula I is smaller than 10 and larger than 15, the carbon chain is too short to be beneficial to the dispersion of the compound, and too long to be beneficial to the crystallization of polypropylene, so that the transparency of the polypropylene is reduced.
Examples 6 to 9
The polypropylene of examples 6-9 was prepared in a manner substantially similar to that of example 1, except that the amount of the compound of formula I in step (3) was varied, as follows:
Example 6 the compound of formula I was used in an amount of 0.1% based on the mass of the polypropylene matrix resin;
example 7 the compound of formula I was used in an amount of 0.5% based on the mass of the polypropylene matrix resin;
Example 8 the compound of formula I was used in an amount of 0.05% based on the mass of the polypropylene matrix resin;
example 9 the compound of formula I was used in an amount of 0.8% based on the mass of the polypropylene matrix resin;
The polypropylene samples of examples 6-9 were subjected to performance testing and the test results are shown in Table 3, respectively.
TABLE 3 Performance test Table of the polypropylenes of example 1 and examples 6-9
| Sequence number | 3, 5-Dimethylbenzaldehyde mass ratio | Haze/% | Smell of |
| Example 1 | 8% | 8.7 | 1 |
| Example 6 | 8% | 8.3 | 2 |
| Example 7 | 8% | 9.8 | 1 |
| Example 8 | 8% | 8.1 | 3 |
| Example 9 | 8% | 10.3 | 1 |
Referring to Table 3, it can be seen that the compounds of formula I are used in amounts of 0.1% -0.5% in comparative examples 1, 6, 7 and examples 8, 9, which are advantageous for inhibiting odor generation of polypropylene and also provide excellent transparency properties to polypropylene. When the addition amount of the compound shown in the formula I is less than 0.1%, the inhibition of the decomposition of sorbitol acetal is limited, so that the prepared polypropylene is easy to generate obvious smell, and when the addition amount of the compound shown in the formula I is more than 0.5%, excessive amorphous areas are formed in the polypropylene, so that the transparency of the polypropylene is reduced.
Example 10
The polypropylene of example 10 was prepared in a manner substantially similar to that of example 1, except that the imidazole-based ionic liquid was further added in step (1), and the specific preparation method of step (1) was as follows:
Adding 100 parts by weight of o-xylene and 200 parts by weight of 1, 2-dichloroethane, starting a stirrer, pre-cooling the materials in the reaction bottle to-20 ℃ to-10 ℃, sequentially adding 3-4 drops of concentrated hydrochloric acid, 130 parts by weight of anhydrous AlCl 3 serving as a catalyst, introducing nitrogen for displacement, controlling the operation temperature to-10 ℃ to-5 ℃, introducing carbon monoxide, keeping the partial pressure of the carbon monoxide to 1.0Mpa, and starting timing reaction. After 2.5h of reaction, the carbon monoxide ventilation valve is closed, stirring is continued, then the reactants are poured into a prepared ice salt water flask with the temperature of-10 ℃ to-5 ℃, after stirring, the mixture is placed in a separating funnel, the mixture is extracted and shaken uniformly, the mixture is kept stand for layering, the lower acid water is separated to obtain an upper oily substance, 1-methyl-3-butylimidazole bisulfate accounting for 0.05 percent of the total mass of the oily substance is added into the oily substance, catalytic reaction is carried out for 4h at the temperature of-5 ℃, then the reactants are poured into a prepared ice salt water flask with the temperature of-10 ℃ to-5 ℃, after stirring, the mixture is placed in the separating funnel, the mixture is extracted and shaken uniformly, the mixture is kept stand for layering, the lower solution is separated to obtain the upper solution, the upper solution is placed into a distillation flask for normal pressure distillation, and the solvent is removed to obtain the prepared dimethylbenzaldehyde. The mass ratio of 3, 5-dimethylbenzaldehyde in the dimethylbenzaldehyde obtained by the test is 24%.
And in the preparation of the polypropylene in the step (3), the mass ratio of the compound shown in the formula I to the polypropylene matrix resin is 5:1000.
Examples 11 to 14
The polypropylene of examples 11-14 was prepared in a manner substantially similar to that of example 10, except that the amount of 1-methyl-3-butylimidazole bisulfate used in step (1) was changed, as follows:
the amount of 1-methyl-3-butylimidazole bisulfate used in example 11 was 0.01% of the total mass of the oil;
the amount of 1-methyl-3-butylimidazole bisulfate used in example 12 was 0.1% of the total mass of the oil;
the amount of 1-methyl-3-butylimidazole bisulfate used in example 13 was 0.005% of the total mass of the oil;
the amount of 1-methyl-3-butylimidazole bisulfate used in example 14 was 0.2% of the total mass of the oil;
The polypropylene samples of examples 10-14 were tested for performance and the test results are shown in Table 4, respectively.
TABLE 4 Performance test Table of the polypropylenes of example 1 and examples 10-14
| Sequence number | 3, 5-Dimethylbenzaldehyde mass ratio | Haze/% | Smell of |
| Example 1 | 8% | 8.7 | 1 |
| Example 10 | 24% | 7.1 | 1 |
| Example 11 | 16% | 7.7 | 1 |
| Example 12 | 38% | 6.8 | 2 |
| Example 13 | 12% | 8.2 | 1 |
| Example 14 | 43% | 6.6 | 4 |
Referring to Table 4, it can be seen from a comparison of example 1 and example 10 that the addition of imidazole ionic liquid for catalytic electrophilic rearrangement is beneficial to increasing the content of 3, 5-dimethylbenzaldehyde in dimethylbenzaldehyde. When the transparent nucleating agent is used for preparing polypropylene, the compound shown in the formula I is matched with the decomposition inhibition effect of sorbitol acetal, so that the haze of the polypropylene is further reduced, and meanwhile, no peculiar smell is generated. As can be seen from the comparison of examples 10-12 and examples 13 and 14, when the amount of the imidazole ion liquid is 0.01% to 0.1% of the total mass of the oil, the polypropylene has excellent transparency and no obvious odor, when the amount of the imidazole ion liquid is less than 0.01%, the 3, 5-dimethylbenzaldehyde content in dimethylbenzaldehyde is too small, which is unfavorable for improving the transparency of the polypropylene, and when the amount of the imidazole ion liquid is more than 0.1%, the 3, 5-dimethylbenzaldehyde content in dimethylbenzaldehyde is too large, so that the unstable sorbitol acetal content in the transparent nucleating agent is too much, which leads to the generation of the odor of the polypropylene.
Examples 15 to 18
The polypropylene of examples 15-18 was prepared in a manner substantially similar to that of example 10, except that the time of the catalytic reaction in step (1) was varied, as follows:
the catalytic reaction time for example 15 was 1h;
The catalytic reaction time for example 16 was 6h;
the catalytic reaction time for example 17 was 0.5h;
the catalytic reaction time for example 18 was 8h;
the polypropylene samples of examples 15-18 were tested for performance and the test results are shown in Table 5, respectively.
TABLE 5 Performance test Table of the polypropylenes of example 10 and examples 15-18
| Sequence number | 3, 5-Dimethylbenzaldehyde mass ratio | Haze/% | Smell of |
| Example 10 | 24% | 7.1 | 1 |
| Example 15 | 17% | 7.6 | 1 |
| Example 16 | 35% | 6.9 | 2 |
| Example 17 | 10% | 8.6 | 1 |
| Example 18 | 33% | 7.0 | 3 |
Referring to Table 5, it is understood from comparison of examples 10, 15-18 that the time for catalyzing the electrophilic rearrangement reaction is 1h-6h, which is advantageous in controlling the content of 3, 5-dimethylbenzaldehyde in dimethylbenzaldehyde within a proper range, and polypropylene has excellent transparency and no obvious odor. When the time of the catalytic electrophilic rearrangement reaction is less than 1h, the content of 3, 5-dimethylbenzaldehyde in dimethylbenzaldehyde is too small, which is unfavorable for improving the transparency of polypropylene, and when the time of the catalytic electrophilic rearrangement reaction is more than 6h, the content of 3, 5-dimethylbenzaldehyde in dimethylbenzaldehyde is unfavorable for further improving, and by-products can be generated, so that the polypropylene generates odor.
Example 19
The polypropylene of example 19 was prepared in a manner substantially similar to that of example 10, except that the type of the imidazole ionic liquid used in step (1) was changed, and the imidazole ionic liquid used in example 19 was 1-butyl-3-methylimidazolium hexafluorophosphate.
Comparative example 4
The polypropylene of comparative example 4 was prepared in a substantially similar manner to example 10, except that concentrated hydrochloric acid was used as a catalyst in comparative example 4.
The polypropylene samples of example 19 and comparative example 4 were subjected to performance test, and the test results are shown in Table 6, respectively.
TABLE 6 Performance test Table of the polypropylenes of example 19 and comparative example 4
| Sequence number | 3, 5-Dimethylbenzaldehyde mass ratio | Haze/% | Smell of |
| Example 10 | 24% | 7.1 | 1 |
| Example 19 | 17% | 7.7 | 1 |
| Comparative example 4 | 37% | 6.8 | 5 |
Referring to Table 6, it is understood from a comparison of example 10 and example 19 that when 1-methyl-3-butylimidazole bisulfate is used as the imidazole ionic liquid, it is more advantageous to catalyze the electrophilic rearrangement reaction and to raise the content of 3, 5-dimethylbenzaldehyde in dimethylbenzaldehyde, thereby reducing the haze of polypropylene. As can be seen from a comparison of examples 10, 19 and comparative example 4, the rate of the catalytic electrophilic rearrangement reaction was too severe and byproducts were easily generated using hydrochloric acid as a catalyst, resulting in significant off-flavors in polypropylene. Compared with hydrochloric acid, the imidazole ionic liquid is used as a catalyst, has mildness, can reduce side reactions, improves the transparency of polypropylene, and does not generate peculiar smell.
The present embodiment is only for explanation of the present application and is not to be construed as limiting the present application, and modifications to the present embodiment, which may not creatively contribute to the present application as required by those skilled in the art after reading the present specification, are all protected by patent laws within the scope of claims of the present application.
Claims (8)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411398471.2A CN119039704B (en) | 2024-10-09 | 2024-10-09 | A method for preparing transparent polypropylene |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411398471.2A CN119039704B (en) | 2024-10-09 | 2024-10-09 | A method for preparing transparent polypropylene |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN119039704A CN119039704A (en) | 2024-11-29 |
| CN119039704B true CN119039704B (en) | 2025-06-13 |
Family
ID=93569026
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202411398471.2A Active CN119039704B (en) | 2024-10-09 | 2024-10-09 | A method for preparing transparent polypropylene |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN119039704B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102250398A (en) * | 2010-05-18 | 2011-11-23 | 中国石油天然气股份有限公司 | Polyolefin nucleating agent and preparation and application thereof |
| CN103524313A (en) * | 2013-10-08 | 2014-01-22 | 南京航空航天大学 | 3,5-dimethylbenzaldehyde preparation method |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102725348B (en) * | 2010-03-29 | 2014-02-05 | 株式会社艾迪科 | Clarifying agent composition containing sorbitol compound and method for producing polypropylene-based resin composition using the sorbitol compound |
| CN104558823A (en) * | 2013-10-29 | 2015-04-29 | 中国石油化工股份有限公司 | Method for reducing melting point of polypropylene transparent nucleating agent |
| CN104163984B (en) * | 2013-10-31 | 2016-08-24 | 中国石油化工股份有限公司 | A kind of polyolefine resin composition and preparation method thereof |
| CN105753672A (en) * | 2016-03-31 | 2016-07-13 | 常州大学 | Synthesis method for 3,5-dimethyl benzaldehyde |
| CN113330058B (en) * | 2019-01-21 | 2024-10-11 | 株式会社Adeka | Nucleating agent composition, olefin resin composition, molded article thereof, and process for producing olefin resin composition |
| CN111718358B (en) * | 2020-07-07 | 2022-11-15 | 山东齐润源新材料科技有限公司 | Preparation method of high-fluidity polypropylene nucleating agent |
| CN112606257B (en) * | 2020-10-29 | 2022-08-23 | 杭州聚丰新材料有限公司 | Low-odor and narrow-molecular-weight-distribution high-melt-index polypropylene and preparation method thereof |
| CN114524974B (en) * | 2021-12-30 | 2024-04-09 | 弘元(上海)高分子材料有限公司 | Nucleating agent composition for transparent polypropylene and application thereof and polypropylene composition |
| CN114315852B (en) * | 2022-01-18 | 2024-03-12 | 营口风光新材料股份有限公司 | Method for preparing 3, 4-dimethylbenzylidene sorbitol with zero byproduct |
-
2024
- 2024-10-09 CN CN202411398471.2A patent/CN119039704B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102250398A (en) * | 2010-05-18 | 2011-11-23 | 中国石油天然气股份有限公司 | Polyolefin nucleating agent and preparation and application thereof |
| CN103524313A (en) * | 2013-10-08 | 2014-01-22 | 南京航空航天大学 | 3,5-dimethylbenzaldehyde preparation method |
Non-Patent Citations (2)
| Title |
|---|
| 二亚苄基山梨糖醇类成核剂脱除气味的方法;王小强等;《石化技术与应用》;20020831;第20卷(第4期);"2.2.2 添加醛类去除剂"部分 * |
| 吴雨龙等.CO羰基化合成 3,4-二甲基苯甲醛的反应机理研究.《广东化工》.2006,第33卷(第164期),"1.3 实验过程"部分、"2.1 实验的图谱及产物组成"部分、"3 结论"部分. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN119039704A (en) | 2024-11-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101484458B (en) | Dibenzylidene sorbitol (dbs)-based compounds, compositions and methods for using such compounds | |
| KR101821380B1 (en) | Methyl methacrylate purification process | |
| KR20100042579A (en) | Method of preparing of 60% or more cis-di(c4-c20)alkyl cyclohexane-1,4-dicarboxylate | |
| CN104736507B (en) | The preparation method of anhydrous sugar alcohol | |
| CN102320970A (en) | With the modified cation-exchange resin is the method for Preparation of Catalyst tributyl citrate | |
| CN101605774B (en) | 2-methyl-3-(3,4-methylenedioxyphenyl)propanal and its production method | |
| WO2000007969A1 (en) | 1,3-butylene glycol of high purity and method for producing the same | |
| EP2607341B1 (en) | Trimethylolpropane color improvement | |
| CN119039704B (en) | A method for preparing transparent polypropylene | |
| CN103539668B (en) | Process for synthesizing terephthalal diethyl dimalonate ultraviolet light absorber | |
| CN101462930B (en) | Preparation of beta-dione | |
| IE46063B1 (en) | Process for producing 2,4,6-tri-(4-hydroxy-3,5-di-t-butylbenzyl) mesitylene | |
| EP2940023B1 (en) | Method of preparing diacetal-based clarifying agent | |
| KR101392883B1 (en) | Method for producing anhydrosugar alcohols having remarkably reduced ion content and improved color property | |
| CN102260156A (en) | Method for preparing medicinal intermediate of p-methoxypropiophenone | |
| CN102250398A (en) | Polyolefin nucleating agent and preparation and application thereof | |
| CA2395061A1 (en) | Process for producing high-purity bis-.beta.-hydroxyethyl terephthalate | |
| CN101391957A (en) | A kind of method for preparing tributyl citrate by rare earth salt binary complex solid acid catalysis | |
| CN100413856C (en) | A kind of preparation method of whiskey lactone | |
| CN112831126A (en) | High-molecular film material resistant to cooking and preparation method thereof | |
| CN116730841A (en) | Preparation method for synthesizing bisphenol monoacrylate antioxidant with low cost and high selectivity | |
| CN114437021B (en) | A kind of patchouli aroma compound and its preparation method | |
| JPH08176158A (en) | 1,3-2,4-di (4-methylbenzylidene) sorbitol and resin composition containing the same | |
| CN1026235C (en) | Synthesis method of fosfomycin trometamol salt | |
| CN115160132B (en) | Production process of benzyl benzoate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |