CN114350062A - High-rigidity low-yield polypropylene tangle film and preparation method thereof - Google Patents
High-rigidity low-yield polypropylene tangle film and preparation method thereof Download PDFInfo
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Abstract
The invention discloses a high-rigidity low-yield polypropylene twisted film and a preparation method thereof, and relates to the technical field of twisted films.
Description
The technical field is as follows:
the invention relates to the technical field of a tangle film, in particular to a high-rigidity low-yield polypropylene tangle film and a preparation method thereof.
Background art:
the tangle film is a film for packaging candies, and is one of the most traditional candy packaging methods, namely three packaging methods of pillow bag, folding type packaging and candy packaging. The existing tangle film is classified into cellophane (cellophane), hard PVC, uniaxially stretched HDPE, biaxially stretched PS, PP, and PET. The PP (polypropylene) tangle film has the advantages of environmental protection, sanitation, good moisture resistance, low price, good dimensional stability, high transparency and corrosion resistance, but has poor rigidity and stiffness.
At present, the method for improving the performance of the polypropylene kink membrane comprises two aspects of a synthesis method and a processing method, wherein the synthesis method is to add a benzene ring or a five-membered ring with large molecular steric hindrance on a main chain of a polypropylene molecular chain to reduce intermolecular force, but the synthesis method has the problems of long time consumption, high cost and long research period. The processing method comprises two methods, one method is a multilayer co-extrusion composite aluminum film which has excellent strength and rigidity and better kinking property, but has poor corrosion resistance and is difficult to recycle; the other is adding the twisting auxiliary agent, which has higher rigidity, obstructs the movement of the molecular chain of the film and weakens the recovery capability, thereby improving the twisting performance of the twisted film, but the processing conditions have great influence on the crystal form and the crystallinity and have complex control factors.
The invention content is as follows:
the invention aims to solve the technical problem of providing a high-rigidity low-yield polypropylene tangle film and a preparation method thereof, wherein the crystallinity of polypropylene is regulated and controlled by adding hydrogenated petroleum resin and a nucleating agent, and the crystal structure of the polypropylene is changed, so that the packaging performance of the polypropylene tangle film as a packaging material is optimized.
The technical problem to be solved by the invention is realized by adopting the following technical scheme:
the high-rigidity low-yield polypropylene tangle film is prepared from the following raw materials in parts by weight:
80-100 parts of polypropylene, 10-20 parts of hydrogenated petroleum resin and 5-10 parts of nucleating agent;
the nucleating agent is N, N ' - ([2,2' -bipyridyl ] -6,6' -diyl) bis (3- (4-fluorophenyl) propionamide), and the structural formula is as follows:
the polypropylene is homo-polypropylene or co-polypropylene.
The hydrogenated petroleum resin is C5 hydrogenated petroleum resin or C9 hydrogenated petroleum resin.
The hydrogenated petroleum resin has higher rigidity and difficult molecular chain movement, and can reduce the crystallinity of PP, enlarge an amorphous region and reduce the torsion restoring force.
The N, N ' - ([2,2' -bipyridyl ] -6,6' -diyl) bis (3- (4-fluorophenyl) propionamide) is prepared by reacting 2,2' -bipyridyl-6, 6' -diamine and 3- (4-fluorophenyl) propionic acid, and the preparation method comprises the following steps: under the anhydrous condition, adding 3- (4-fluorophenyl) propionic acid into tetrahydrofuran, then dropwise adding thionyl chloride, reacting at normal temperature, vacuumizing after the reaction is finished, removing redundant thionyl chloride and tetrahydrofuran, adding 2,2 '-bipyridine-6, 6' -diamine into the obtained 3- (4-fluorophenyl) propionyl chloride, dehydrating, washing with water, carrying out suction filtration, and drying to obtain the product.
The molar ratio of the 2,2 '-bipyridine-6, 6' -diamine, the 3- (4-fluorophenyl) propionic acid and the thionyl chloride is 1:1: 2-5.
The nucleating agent can improve the crystallinity and the elastic modulus of PP, control the proportion of an amorphous phase and a crystalline phase and regulate and control the crystal form. The nucleating agent is in a fiber shape after being melted, can induce polypropylene to be oriented and overgrown and crystallized, and polypropylene forms different crystal forms through profiling growth. Moreover, the action effect of the novel nucleating agent is superior to that of the existing TMB nucleating agent, NU nucleating agent and WBG nucleating agent in the field.
By regulating the competitive relationship between the hydrogenated petroleum resin and the nucleating agent, the crystallization and orientation forms of PP are controlled, a PP crystal structure with a high amorphous area and a high length-diameter ratio is constructed, the elastic modulus of a tangle film is improved, and the elongation at break is reduced.
The preparation method of the high-rigidity low-yield polypropylene tangle film comprises the following preparation steps:
(1) fully mixing polypropylene, hydrogenated petroleum resin and a nucleating agent which are dried in vacuum until the water content is lower than 250ppm to obtain a premix;
(2) adding the premix into a double-screw extruder, melting and plasticizing, extruding through a die head, and performing quenching and shaping to obtain a membrane;
(3) and preheating the membrane, performing biaxial tension, cooling and shaping, cutting edges, and rolling to obtain the twisted film.
The vacuum drying temperature is 60-80 ℃.
The melting plasticizing temperature is 185-215 ℃, the die head extrusion temperature is 200-230 ℃, and the quenching setting temperature is 20-50 ℃.
The preheating temperature is 80-100 ℃, the biaxial stretching temperature is 115-135 ℃, and the cooling and shaping temperature is 40-60 ℃.
The longitudinal stretching magnification of the bidirectional stretching is 2-5 times, and the transverse stretching magnification is 2-5 times.
The invention has the beneficial effects that: the invention takes the polypropylene as the base material, regulates and controls the crystallinity of the polypropylene by adding the hydrogenated petroleum resin and the nucleating agent, and changes the crystal structure of the polypropylene, thereby optimizing the packaging performance of the prepared polypropylene twisted film as the packaging material, simultaneously ensuring the safety performance of the polypropylene twisted film as the candy packaging material, and the polypropylene twisted film can be recycled, improving the resource utilization efficiency, and further reducing the pollution to the environment.
The specific implementation mode is as follows:
in order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.
Nucleating agent N, N '- ([2,2' -bipyridine)]Preparation of-6, 6' -diyl) bis (3- (4-fluorophenyl) propionamide): adding 0.05mol of 3- (4-fluorophenyl) propionic acid into 250mL of tetrahydrofuran under anhydrous condition, then dropwise adding 0.15mol of thionyl chloride, reacting for 2 hours at normal temperature, vacuumizing after the reaction is finished, removing redundant thionyl chloride and tetrahydrofuran, addingAdding 0.05mol of 2,2 '-dipyridine-6, 6' -diamine into the obtained 3- (4-fluorophenyl) propionyl chloride, performing dehydration reaction for 3h at 130 ℃, washing with water, performing suction filtration, and drying to obtain the compound.1H NMR(DMSO-d6,400MHz),δ:10.67(s,2H),8.98(d,2H),7.86-7.78(m,4H),7.18-7.16(m,8H),2.96(t,4H),2.79(t,4H)；ESI-MS:m/z＝487.19[M+1]+.
Example 1
(1) 90 parts of homopolypropylene S1040 dried at 65 ℃ under vacuum to have a water content of less than 250ppm, 12 parts of C5 hydrogenated petroleum resin, and 6 parts of the above-prepared nucleating agent were thoroughly mixed to obtain a premix.
(2) Adding the premix into a double-screw extruder, melting and plasticizing, wherein the temperature of each section of a charging barrel of the double-screw extruder is 185 ℃, 195 ℃, 200 ℃, 210 ℃, and 200 ℃ in sequence, extruding by a die head, the temperature of the die head is 200 ℃, and carrying out quenching and shaping on a cooling roller at 25 ℃ to obtain the diaphragm.
(3) Preheating the membrane at 90 ℃, performing biaxial stretching at the biaxial stretching temperature of 125 ℃, the longitudinal stretching magnification of 4 times and the transverse stretching magnification of 2.5 times, cooling and shaping on a cooling roller at 50 ℃, cutting edges, and rolling to obtain a twisted film.
Example 2
(1) 100 parts of homopolypropylene S1040 dried at 65 ℃ in vacuum to have a water content of less than 250ppm, 15 parts of C5 hydrogenated petroleum resin, and 8 parts of the above-prepared nucleating agent were thoroughly mixed to obtain a premix.
(2) Adding the premix into a double-screw extruder, melting and plasticizing, wherein the temperature of each section of a charging barrel of the double-screw extruder is 185 ℃, 195 ℃, 200 ℃, 210 ℃, and 200 ℃ in sequence, extruding by a die head, the temperature of the die head is 200 ℃, and carrying out quenching and shaping on a cooling roller at 25 ℃ to obtain the diaphragm.
(3) Preheating the membrane at 90 ℃, performing biaxial stretching at the biaxial stretching temperature of 125 ℃, the longitudinal stretching magnification of 4 times and the transverse stretching magnification of 2.5 times, cooling and shaping on a cooling roller at 50 ℃, cutting edges, and rolling to obtain a twisted film.
Example 3
(1) 90 parts of homopolypropylene S1040 dried at 65 ℃ under vacuum to have a water content of less than 250ppm, 12 parts of C9 hydrogenated petroleum resin, and 6 parts of the above-prepared nucleating agent were thoroughly mixed to obtain a premix.
(2) Adding the premix into a double-screw extruder, melting and plasticizing, wherein the temperature of each section of a charging barrel of the double-screw extruder is 185 ℃, 195 ℃, 200 ℃, 210 ℃, and 200 ℃ in sequence, extruding by a die head, the temperature of the die head is 200 ℃, and carrying out quenching and shaping on a cooling roller at 25 ℃ to obtain the diaphragm.
(3) Preheating the membrane at 90 ℃, performing biaxial stretching at the biaxial stretching temperature of 125 ℃, the longitudinal stretching magnification of 4 times and the transverse stretching magnification of 2.5 times, cooling and shaping on a cooling roller at 50 ℃, cutting edges, and rolling to obtain a twisted film.
Comparative example 1
Comparative example 1 differs from example 1 in that the nucleating agent was replaced with a nucleating agent WBG-2.
(1) 90 parts of homopolypropylene S1040, 12 parts of C5 hydrogenated petroleum resin and 6 parts of a nucleating agent WBG-2, which were vacuum-dried at 65 ℃ to a water content of less than 250ppm, were thoroughly mixed to obtain a premix.
(2) Adding the premix into a double-screw extruder, melting and plasticizing, wherein the temperature of each section of a charging barrel of the double-screw extruder is 185 ℃, 195 ℃, 200 ℃, 210 ℃, and 200 ℃ in sequence, extruding by a die head, the temperature of the die head is 200 ℃, and carrying out quenching and shaping on a cooling roller at 25 ℃ to obtain the diaphragm.
(3) Preheating the membrane at 90 ℃, performing biaxial stretching at the biaxial stretching temperature of 125 ℃, the longitudinal stretching magnification of 4 times and the transverse stretching magnification of 2.5 times, cooling and shaping on a cooling roller at 50 ℃, cutting edges, and rolling to obtain a twisted film.
Comparative example 2
Comparative example 2 differs from example 1 in that the nucleating agent was replaced with the nucleating agent NU-100.
(1) 90 parts of homopolypropylene S1040 dried at 65 ℃ in vacuum to a water content of less than 250ppm, 12 parts of C5 hydrogenated petroleum resin and 6 parts of nucleating agent NU-100 are fully mixed to obtain the premix.
(2) Adding the premix into a double-screw extruder, melting and plasticizing, wherein the temperature of each section of a charging barrel of the double-screw extruder is 185 ℃, 195 ℃, 200 ℃, 210 ℃, and 200 ℃ in sequence, extruding by a die head, the temperature of the die head is 200 ℃, and carrying out quenching and shaping on a cooling roller at 25 ℃ to obtain the diaphragm.
(3) Preheating the membrane at 90 ℃, performing biaxial stretching at the biaxial stretching temperature of 125 ℃, the longitudinal stretching magnification of 4 times and the transverse stretching magnification of 2.5 times, cooling and shaping on a cooling roller at 50 ℃, cutting edges, and rolling to obtain a twisted film.
Comparative example 3
Comparative example 3 differs from example 1 in that the nucleating agent was replaced with the nucleating agent TMB-5.
(1) 90 parts of homopolypropylene S1040, 12 parts of C5 hydrogenated petroleum resin and 6 parts of a nucleating agent TMB-5 which are vacuum-dried at 65 ℃ until the water content is less than 250ppm are fully mixed to obtain a premix.
(2) Adding the premix into a double-screw extruder, melting and plasticizing, wherein the temperature of each section of a charging barrel of the double-screw extruder is 185 ℃, 195 ℃, 200 ℃, 210 ℃, and 200 ℃ in sequence, extruding by a die head, the temperature of the die head is 200 ℃, and carrying out quenching and shaping on a cooling roller at 25 ℃ to obtain the diaphragm.
(3) Preheating the membrane at 90 ℃, performing biaxial stretching at the biaxial stretching temperature of 125 ℃, the longitudinal stretching magnification of 4 times and the transverse stretching magnification of 2.5 times, cooling and shaping on a cooling roller at 50 ℃, cutting edges, and rolling to obtain a twisted film.
The elasticity modulus and the elongation at break of the kinked film are tested according to the national standard GB/T1040.1-2006 'determination of tensile property of plastics', and the test results are shown in Table 1.
Table 1 elasticity modulus and elongation at break test results of the tangle film
As can be seen from table 1, when N, N ' - ([2,2' -bipyridine ] -6,6' -diyl) bis (3- (4-fluorophenyl) propionamide) prepared according to the present invention is used as a nucleating agent, the elastic modulus of the twisted film can be substantially increased, and the elongation at break of the twisted film can be reduced, so that the twisted film meets the packaging requirements.
The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (10)
1. The high rigidity low yield polypropylene wriggling film is characterized in that: the feed is prepared from the following raw materials in parts by weight:
80-100 parts of polypropylene, 10-20 parts of hydrogenated petroleum resin and 5-10 parts of nucleating agent;
the nucleating agent is N, N ' - ([2,2' -bipyridyl ] -6,6' -diyl) bis (3- (4-fluorophenyl) propionamide), and the structural formula is as follows:
2. the high-rigidity low-yield polypropylene wiggle film according to claim 1, wherein: the polypropylene is homo-polypropylene or co-polypropylene.
3. The high-rigidity low-yield polypropylene wiggle film according to claim 1, wherein: the hydrogenated petroleum resin is C5 hydrogenated petroleum resin or C9 hydrogenated petroleum resin.
4. The high-rigidity low-yield polypropylene wiggle film according to claim 1, wherein: the N, N ' - ([2,2' -bipyridyl ] -6,6' -diyl) bis (3- (4-fluorophenyl) propionamide) is prepared by reacting 2,2' -bipyridyl-6, 6' -diamine and 3- (4-fluorophenyl) propionic acid, and the preparation method comprises the following steps: under the anhydrous condition, adding 3- (4-fluorophenyl) propionic acid into tetrahydrofuran, then dropwise adding thionyl chloride, reacting at normal temperature, vacuumizing after the reaction is finished, removing redundant thionyl chloride and tetrahydrofuran, adding 2,2 '-bipyridine-6, 6' -diamine into the obtained 3- (4-fluorophenyl) propionyl chloride, dehydrating, washing with water, carrying out suction filtration, and drying to obtain the product.
5. The high-rigidity low-yield polypropylene wiggle film according to claim 4, wherein: the molar ratio of the 2,2 '-bipyridine-6, 6' -diamine, the 3- (4-fluorophenyl) propionic acid and the thionyl chloride is 1:1: 2-5.
6. The method for producing a high-rigidity low-yield polypropylene tangle film according to any one of claims 1 to 5, wherein: comprises the following preparation steps:
(1) fully mixing polypropylene, hydrogenated petroleum resin and a nucleating agent which are dried in vacuum until the water content is lower than 250ppm to obtain a premix;
(2) adding the premix into a double-screw extruder, melting and plasticizing, extruding through a die head, and performing quenching and shaping to obtain a membrane;
(3) and preheating the membrane, performing biaxial tension, cooling and shaping, cutting edges, and rolling to obtain the twisted film.
7. The method for preparing a high-rigidity low-yield polypropylene tangle film according to claim 6, wherein: the vacuum drying temperature is 60-80 ℃.
8. The method for preparing a high-rigidity low-yield polypropylene tangle film according to claim 6, wherein: the melting plasticizing temperature is 185-215 ℃, the die head extrusion temperature is 200-230 ℃, and the quenching setting temperature is 20-50 ℃.
9. The method for preparing a high-rigidity low-yield polypropylene tangle film according to claim 6, wherein: the preheating temperature is 80-100 ℃, the biaxial stretching temperature is 115-135 ℃, and the cooling and shaping temperature is 40-60 ℃.
10. The method for preparing a high-rigidity low-yield polypropylene tangle film according to claim 6, wherein: the longitudinal stretching magnification of the bidirectional stretching is 2-5 times, and the transverse stretching magnification is 2-5 times.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1231207A1 (en) * | 1999-11-15 | 2002-08-14 | Sankio Chemical Co., Ltd. | Novel bipyridyl derivatives |
| CN101161706A (en) * | 2007-09-18 | 2008-04-16 | 佛山塑料集团股份有限公司 | Knot film and method for manufacturing same |
| JP2009144056A (en) * | 2007-12-14 | 2009-07-02 | Nagoya City | Nucleating agent for polylactic acid and polylactic acid resin composition |
| CN102040532A (en) * | 2009-10-21 | 2011-05-04 | 中国石油化工股份有限公司 | Preparation method of polypropylene beta crystalline nucleating agent |
| CN102344388A (en) * | 2011-07-19 | 2012-02-08 | 四川大学 | Polypropylene beta nucleating agent and its preparation method and use |
| CN106866636A (en) * | 2016-12-27 | 2017-06-20 | 中国石油天然气股份有限公司 | A kind of sub- amide-type beta crystal-type nucleater and preparation method and application |
| CN111732758A (en) * | 2020-07-02 | 2020-10-02 | 重庆文理学院 | 1, 4-naphthalenedicarboxylic acid dihyrozide nucleating agent and preparation method thereof |
-
2021
- 2021-12-08 CN CN202111494638.1A patent/CN114350062B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1231207A1 (en) * | 1999-11-15 | 2002-08-14 | Sankio Chemical Co., Ltd. | Novel bipyridyl derivatives |
| US6603007B1 (en) * | 1999-11-15 | 2003-08-05 | Sankio Chemical Co., Ltd. | Bipyridyl derivatives |
| CN101161706A (en) * | 2007-09-18 | 2008-04-16 | 佛山塑料集团股份有限公司 | Knot film and method for manufacturing same |
| JP2009144056A (en) * | 2007-12-14 | 2009-07-02 | Nagoya City | Nucleating agent for polylactic acid and polylactic acid resin composition |
| CN102040532A (en) * | 2009-10-21 | 2011-05-04 | 中国石油化工股份有限公司 | Preparation method of polypropylene beta crystalline nucleating agent |
| CN102344388A (en) * | 2011-07-19 | 2012-02-08 | 四川大学 | Polypropylene beta nucleating agent and its preparation method and use |
| CN106866636A (en) * | 2016-12-27 | 2017-06-20 | 中国石油天然气股份有限公司 | A kind of sub- amide-type beta crystal-type nucleater and preparation method and application |
| CN111732758A (en) * | 2020-07-02 | 2020-10-02 | 重庆文理学院 | 1, 4-naphthalenedicarboxylic acid dihyrozide nucleating agent and preparation method thereof |
| CN113150381A (en) * | 2020-07-02 | 2021-07-23 | 重庆文理学院 | 1, 4-naphthalenedicarboxylic acid dihyrozide nucleating agent and preparation method thereof |
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