阅读说明：本技术 一种高性能聚丙烯镀铝基膜及其制备方法 (High-performance polypropylene aluminum-plated base film and preparation method thereof ) 是由 郑国星 薛圣光 尤良铁 徐董 于 2021-01-06 设计创作，主要内容包括：本发明公开了一种高性能聚丙烯镀铝基膜,包括上表层、芯层和下表层,所述上表层由重量百分比为94-98％的二元共聚聚丙烯、重量百分比为2-4％的防粘剂和重量百分比为2-4％的驻极母料制备而成；所述芯层由重量百分比为100％的均聚聚丙烯制备而成；所述下表层由重量百分比为96-98％的二元共聚聚丙烯和重量百分比为2-4％的防粘剂制备而成。上述技术方案,在薄膜内部添加驻极母料,使得薄膜的表面湿润张力得到极大的提高,镀铝的牢度显著的提升,表面湿润张力好、镀铝牢度高且实用性好,解决了下游客户薄膜镀铝的痛点,提高了产品的附加值。(The invention discloses a high-performance polypropylene aluminized base film, which comprises an upper surface layer, a core layer and a lower surface layer, wherein the upper surface layer is prepared from 94-98 wt% of binary copolymer polypropylene, 2-4 wt% of an anti-sticking agent and 2-4 wt% of electret master batch; the core layer is prepared from 100 wt% of homopolymerized polypropylene; the lower surface layer is prepared from 96-98 wt% of binary copolymer polypropylene and 2-4 wt% of anti-sticking agent. According to the technical scheme, the electret master batch is added in the film, so that the surface wetting tension of the film is greatly improved, the aluminizing fastness is remarkably improved, the surface wetting tension is good, the aluminizing fastness is high, the practicability is good, the problem of pain in aluminizing of the film of a downstream customer is solved, and the added value of a product is improved.)

1. A high-performance polypropylene aluminized base film comprises an upper surface layer, a core layer and a lower surface layer, and is characterized in that: the upper surface layer is prepared from 94-98 wt% of binary copolymer polypropylene, 2-4 wt% of anti-sticking agent and 2-4 wt% of electret master batch; the core layer is prepared from 100 wt% of homopolymerized polypropylene; the lower surface layer is prepared from 96-98 wt% of binary copolymer polypropylene and 2-4 wt% of anti-sticking agent.

2. The high-performance polypropylene aluminized base film according to claim 1, characterized in that: the thickness of the upper layer is 1.1-1.5 microns, and the thickness of the lower layer is 0.9-1.2 microns.

3. The high-performance polypropylene aluminized base film according to claim 2, characterized in that: the melt index of the binary copolymer polypropylene is 7.5-9.5g/10min, and the model is KS 407.

4. A high-performance polypropylene aluminum-plated base film according to claim 3, wherein: the anti-sticking agent is an organic anti-sticking agent with the model AB6056 PPR.

5. The high-performance polypropylene aluminized base film according to claim 4, characterized in that: the melting index of the electret master batch is 6-8g/10min, and the main components of the electret master batch are polypropylene and electret materials.

6. The high-performance polypropylene aluminized base film according to claim 5, characterized in that: the isotactic degree of the homopolymerized polypropylene is 97-98%, the melt index is 2.5-3.5g/10min, and the type is F03D (QD).

7. Process for the preparation of an electret masterbatch according to any one of claims 1 to 6, characterized in that: the method comprises the following steps:

1. stirring and uniformly mixing the required raw materials in proportion, and loading the mixture into a hopper of an extruder;

2. controlling the temperature and the rotating speed of the extruder, and extruding the mixed raw materials into a plurality of strips from a die head;

3. cooling the extruded strip master batch by using cooling water quickly, and drying by using circulating air after shaping;

4. and cutting the dried master batch into small particles by a granulator, sucking the small particles into a storage bin, drying the small particles again and bagging the dried small particles.

8. A method for preparing a high-performance polypropylene aluminized base film according to any one of claims 1 to 6, characterized in that: the method comprises the following steps:

(1) preparing materials: the raw materials of each component required by the core layer, the first surface layer and the second surface layer are proportioned according to the proportioning requirement and are respectively and fully mixed uniformly;

(2) extruding and casting sheets: melting and plasticizing the uniformly mixed raw materials of each layer in respective extruders; the core layer raw material uses a double-screw extruder, redundant air is removed during raw material plasticization, the extruded raw material is subjected to secondary plasticization, metering and filtration, the set temperature is 245-; finally, extruding the three layers of raw materials from the die head together through corresponding connecting pipes, wherein the temperature of the die head is 235-; the extruded raw materials are uniformly adhered to the surface of the cold roll under the action of an air knife to form a sheet with uniform thickness, and the sheet is rapidly shaped by a chill roll and a water tank and then dried.

(3) And (3) bidirectional stretching: the dried sheet enters a longitudinal stretching area, and longitudinal stretching is completed through preheating, stretching and shaping of different rollers; the thick sheet enters a transverse stretching area, and is sequentially preheated, stretched, shaped and cooled by an air box and a chain to finish transverse stretching; the longitudinal stretching ratio is controlled between 4.8 and 5.5, and the transverse stretching ratio is controlled between 9 and 10.

(4) Traction, thickness measurement and winding: after cooling, flattening and trimming the formed film, performing thickness measurement and automatic control, improving the surface tension through corona treatment, and finally winding the film on a steel core through a double-station winding machine to obtain a semi-finished product;

(5) aging treatment and slitting: and storing the semi-finished product on an aging rack with the temperature of 20-35 ℃ and the humidity of 45-70% for about 48 hours, and slitting by a slitting machine according to the width required by a client to obtain a corresponding finished product roll.

Technical Field

The invention relates to the technical field of film production, in particular to a high-performance polypropylene aluminized base film and a preparation method thereof.

Background

With the continuous improvement of people's life, the need for packaging food is increasing, and the BOPP food packaging bag is widely used in people's life as a good-quality and cheap commodity. The BOPP food packaging bag has the advantages of high tensile strength, high heat resistance, good moisture resistance and the like, but also has the defects of weaker oxygen resistance and short food shelf life. In order to improve the oxygen resistance of the BOPP film, downstream manufacturers can carry out aluminum plating treatment on the surface of the film according to requirements.

After corona treatment, the surface wetting tension of a common BOPP film is temporarily greatly improved, but the problem of fast attenuation easily occurs after aging, so that the later aluminizing fastness is low, and even aluminizing cannot be performed.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a high-performance polypropylene aluminized base film with good surface wetting tension, high aluminizing fastness and good practicability and a preparation method thereof.

In order to achieve the purpose, the invention provides the following technical scheme: a high-performance polypropylene aluminized base film comprises an upper surface layer, a core layer and a lower surface layer, wherein the upper surface layer is prepared from 94-98 wt% of binary copolymer polypropylene, 2-4 wt% of an anti-sticking agent and 2-4 wt% of electret master batch; the core layer is prepared from 100 wt% of homopolymerized polypropylene; the lower surface layer is prepared from 96-98 wt% of binary copolymer polypropylene and 2-4 wt% of anti-sticking agent.

Preferably, the thickness of the upper layer is 1.1-1.5 microns, and the thickness of the lower layer is 0.9-1.2 microns.

Preferably, the melt index of the binary copolymer polypropylene is 7.5-9.5g/10min, and the type is KS 407.

Preferably, the anti-sticking agent is an organic anti-sticking agent with the model AB6056 PPR.

Preferably, the melting index of the electret master batch is 6-8g/10min, and the main components of the electret master batch are polypropylene and an electret material.

Preferably, the isotactic degree of the homopolymerized polypropylene is 97-98%, the melt index is 2.5-3.5g/10min, and the type is F03D (QD).

Preferably, the preparation method of the electret masterbatch comprises the following steps:

1. stirring and uniformly mixing the required raw materials in proportion, and loading the mixture into a hopper of an extruder;

2. controlling the temperature and the rotating speed of the extruder, and extruding the mixed raw materials into a plurality of strips from a die head;

3. cooling the extruded strip master batch by using cooling water quickly, and drying by using circulating air after shaping;

4. and cutting the dried master batch into small particles by a granulator, sucking the small particles into a storage bin, drying the small particles again and bagging the dried small particles.

The invention also provides a preparation method of the high-performance polypropylene aluminized base film, which comprises the following steps:

(1) preparing materials: the raw materials of each component required by the core layer, the first surface layer and the second surface layer are proportioned according to the proportioning requirement and are respectively and fully mixed uniformly;

(2) extruding and casting sheets: melting and plasticizing the uniformly mixed raw materials of each layer in respective extruders; the core layer raw material uses a double-screw extruder, redundant air is removed during raw material plasticization, the extruded raw material is subjected to secondary plasticization, metering and filtration, the set temperature is 245-; finally, extruding the three layers of raw materials from the die head together through corresponding connecting pipes, wherein the temperature of the die head is 235-; the extruded raw materials are uniformly adhered to the surface of the cold roll under the action of an air knife to form a sheet with uniform thickness, and the sheet is rapidly shaped by a chill roll and a water tank and then dried.

(3) And (3) bidirectional stretching: the dried sheet enters a longitudinal stretching area, and longitudinal stretching is completed through preheating, stretching and shaping of different rollers; the thick sheet enters a transverse stretching area, and is sequentially preheated, stretched, shaped and cooled by an air box and a chain to finish transverse stretching; the longitudinal stretching ratio is controlled between 4.8 and 5.5, and the transverse stretching ratio is controlled between 9 and 10.

(4) Traction, thickness measurement and winding: after cooling, flattening and trimming the formed film, performing thickness measurement and automatic control, improving the surface tension through corona treatment, and finally winding the film on a steel core through a double-station winding machine to obtain a semi-finished product;

(5) aging treatment and slitting: and storing the semi-finished product on an aging rack with the temperature of 20-35 ℃ and the humidity of 45-70% for about 48 hours, and slitting by a slitting machine according to the width required by a client to obtain a corresponding finished product roll.

The invention has the advantages that: compared with the prior art, the electret master batch is added in the film, so that the surface wetting tension of the film is greatly improved, the aluminizing fastness is remarkably improved, the surface wetting tension is good, the aluminizing fastness is high, the practicability is good, the pain point of aluminizing of the film of a downstream customer is solved, and the added value of the product is improved.

The invention is further described with reference to the following description and specific examples.

Detailed Description

The invention discloses a high-performance polypropylene aluminized base film, which comprises an upper surface layer, a core layer and a lower surface layer, wherein the upper surface layer is prepared from 94-98 wt% of binary copolymer polypropylene, 2-4 wt% of an anti-sticking agent and 2-4 wt% of electret master batch; the core layer is prepared from 100 wt% of homopolymerized polypropylene; the lower surface layer is prepared from 96-98 wt% of binary copolymer polypropylene and 2-4 wt% of anti-sticking agent.

Preferably, the thickness of the upper layer is 1.1-1.5 microns, and the thickness of the lower layer is 0.9-1.2 microns.

Preferably, the melt index of the binary copolymer polypropylene is 7.5-9.5g/10min, and the type is KS 407.

Preferably, the anti-sticking agent is an organic anti-sticking agent with the model AB6056 PPR.

Preferably, the melting index of the electret master batch is 6-8g/10min, and the main components of the electret master batch are polypropylene and an electret material.

Preferably, the isotactic degree of the homopolymerized polypropylene is 97-98%, the melt index is 2.5-3.5g/10min, and the type is F03D (QD).

Preferably, the preparation method of the electret masterbatch comprises the following steps:

1. stirring and uniformly mixing the required raw materials in proportion, and loading the mixture into a hopper of an extruder;

2. controlling the temperature and the rotating speed of the extruder, and extruding the mixed raw materials into a plurality of strips from a die head;

3. cooling the extruded strip master batch by using cooling water quickly, and drying by using circulating air after shaping;

4. and cutting the dried master batch into small particles by a granulator, sucking the small particles into a storage bin, drying the small particles again and bagging the dried small particles.

The invention also provides a preparation method of the high-performance polypropylene aluminized base film, which comprises the following steps:

(1) preparing materials: the raw materials of each component required by the core layer, the first surface layer and the second surface layer are proportioned according to the proportioning requirement and are respectively and fully mixed uniformly;

(2) extruding and casting sheets: melting and plasticizing the uniformly mixed raw materials of each layer in respective extruders; the core layer raw material uses a double-screw extruder, redundant air is removed during raw material plasticization, the extruded raw material is subjected to secondary plasticization, metering and filtration, the set temperature is 245-; finally, extruding the three layers of raw materials from the die head together through corresponding connecting pipes, wherein the temperature of the die head is 235-; the extruded raw materials are uniformly adhered to the surface of the cold roll under the action of an air knife to form a sheet with uniform thickness, and the sheet is rapidly shaped by a chill roll and a water tank and then dried.

(3) And (3) bidirectional stretching: the dried sheet enters a longitudinal stretching area, and longitudinal stretching is completed through preheating, stretching and shaping of different rollers; the thick sheet enters a transverse stretching area, and is sequentially preheated, stretched, shaped and cooled by an air box and a chain to finish transverse stretching; the longitudinal stretching ratio is controlled between 4.8 and 5.5, and the transverse stretching ratio is controlled between 9 and 10.

(4) Traction, thickness measurement and winding: after cooling, flattening and trimming the formed film, performing thickness measurement and automatic control, improving the surface tension through corona treatment, and finally winding the film on a steel core through a double-station winding machine to obtain a semi-finished product;

(5) aging treatment and slitting: and storing the semi-finished product on an aging rack with the temperature of 20-35 ℃ and the humidity of 45-70% for about 48 hours, and slitting by a slitting machine according to the width required by a client to obtain a corresponding finished product roll.

Example 1

A30-micron high-performance polypropylene aluminized base film and a preparation method thereof comprise the following steps:

a high-performance polypropylene aluminized base film comprises an upper surface layer, a core layer and a lower surface layer, wherein the upper surface layer comprises the following components in percentage by weight: 95 percent of binary copolymerized polypropylene, 2.5 percent of anti-sticking agent and 2.5 percent of electret master batch; the core layer comprises the following components in percentage by weight: 100% of homopolymerized polypropylene; the following layers are selected according to the weight percentage: 97.5 percent of binary copolymer polypropylene and 22.5 percent of anti-sticking agent. The thickness of the film is 28.5 microns, wherein the thickness of the upper layer is 1.1-1.5 microns, and the thickness of the lower layer is 0.9-1.2 microns.

A preparation method of a high-performance polypropylene aluminized base film comprises the following steps:

preparing materials: the components of the upper surface layer, the core layer and the lower surface layer are respectively put into the corresponding double-screw extruder through a feeding system according to the weight percentage;

extruding and plasticizing: the core layer raw material enters a double-screw extruder, the raw material is plasticized, vacuumized and measured for secondary plasticization and then extruded, the set temperature is 250 ℃, the upper-layer raw material is extruded by a single-screw extruder, the set temperature is 240 ℃, and the lower-layer raw material is extruded by the single-screw extruder, and the set temperature is 240 ℃; the three layers of raw materials are extruded out of the die head together through corresponding connecting pipes, and the temperature of the die head is 245 ℃.

Cooling the cast sheet: the air knife tightly attaches the extruded molten thick sheet to the chilling roller, and the thick sheet is rapidly cooled by the rotation of the chilling roller in the water tank. The surface temperature of the chill roll is controlled at 38 ℃, and the temperature of the water tank is controlled at 38 ℃; the slab is cooled and dried twice and then stretched in the longitudinal direction.

Longitudinal stretching: the longitudinal stretching is divided into three parts of preheating, stretching and shaping. The temperature of the preheating roller is 130 ℃; the temperature of the stretching roller is 120 ℃, and the stretching magnification is 5.2; the setting roller temperature is 135 ℃. The film drawn longitudinally at 360 meters per second was then passed through a set of guide rolls and stretched transversely.

And (3) transverse stretching: the longitudinal stretching is divided into four parts of preheating, stretching, shaping and cooling. The temperature of the preheating zone for transverse stretching is 174 ℃, the temperature of the stretching zone is 156 ℃, the temperature of the periodic zone is 167 ℃, and the temperature of the cooling zone is indoor temperature. The maximum draw ratio of the film was 9.0 and the exit velocity was 345 m/s. The exiting film is again cooled in air and enters the pulling area.

Traction and winding: and the film entering the traction area is subjected to processes of cooling, trimming, thickness measurement, corona winding and the like to complete the winding work of the film.

And (4) aging and slitting, namely performing primary detection on the collected large film roll through a grade pipe part, placing the large film roll on an aging rack after the large film roll is qualified, performing secondary detection after the aging is finished, and changing the large film roll into the specification required by a customer by a slitting machine after the large film roll is qualified.

Example 2

A common 30-micron polypropylene aluminized base film and a preparation method thereof comprise the following steps:

a common polypropylene aluminized base film comprises an upper surface layer, a core layer and a lower surface layer, wherein the upper surface layer comprises the following components in percentage by weight: 97.5 percent of binary copolymer polypropylene, 2.5 percent of anti-sticking agent and the components; the core layer comprises the following components in percentage by weight: 100% of homopolymerized polypropylene; the following layers are selected according to the weight percentage: 97.5 percent of binary copolymer polypropylene and 22.5 percent of anti-sticking agent. The thickness of the film is 28.5 microns, wherein the thickness of the upper layer is 1.1-1.5 microns, and the thickness of the lower layer is 0.9-1.2 microns.

A preparation method of a high-performance polypropylene aluminized base film comprises the following steps:

preparing materials: the components of the upper surface layer, the core layer and the lower surface layer are respectively put into the corresponding double-screw extruder through a feeding system according to the weight percentage;

extruding and plasticizing: the core layer raw material enters a double-screw extruder, the raw material is plasticized, vacuumized and measured for secondary plasticization and then extruded, the set temperature is 250 ℃, the upper-layer raw material is extruded by a single-screw extruder, the set temperature is 240 ℃, and the lower-layer raw material is extruded by the single-screw extruder, and the set temperature is 240 ℃; the three layers of raw materials are extruded out of the die head together through corresponding connecting pipes, and the temperature of the die head is 245 ℃.

Cooling the cast sheet: the air knife tightly attaches the extruded molten thick sheet to the chilling roller, and the thick sheet is rapidly cooled by the rotation of the chilling roller in the water tank. The surface temperature of the chill roll is controlled at 38 ℃, and the temperature of the water tank is controlled at 38 ℃; the slab is cooled and dried twice and then stretched in the longitudinal direction.

Longitudinal stretching: the longitudinal stretching is divided into three parts of preheating, stretching and shaping. The temperature of the preheating roller is 130 ℃; the temperature of the stretching roller is 120 ℃, and the stretching magnification is 5.2; the setting roller temperature is 135 ℃. The film drawn longitudinally at 360 meters per second was then passed through a set of guide rolls and stretched transversely.

And (3) transverse stretching: the longitudinal stretching is divided into four parts of preheating, stretching, shaping and cooling. The temperature of the preheating zone for transverse stretching is 174 ℃, the temperature of the stretching zone is 156 ℃, the temperature of the periodic zone is 167 ℃, and the temperature of the cooling zone is indoor temperature. The maximum draw ratio of the film was 9.0 and the exit velocity was 345 m/s. The exiting film is again cooled in air and enters the pulling area.

Traction and winding: and the film entering the traction area is subjected to processes of cooling, trimming, thickness measurement, corona winding and the like to complete the winding work of the film.

And (4) aging and slitting, namely performing primary detection on the collected large film roll through a grade pipe part, placing the large film roll on an aging rack after the large film roll is qualified, performing secondary detection after the aging is finished, and changing the large film roll into the specification required by a customer by a slitting machine after the large film roll is qualified.

The following results are obtained by collecting relevant film products and detecting and analyzing the performance indexes of the film products.

And (3) data detection: see table 1.

TABLE 1

The data show that the physical properties of the films produced under the same process conditions are basically the same by using the same detection method, but the surface wetting tension of the films is greatly improved after the electret master batch is added into the films. The film added with the electret master batch is used by downstream customers, so that the aluminizing fastness is obviously improved, which shows that the technical scheme of the invention is reliable and practical.

The above embodiments are described in detail for the purpose of further illustrating the present invention and should not be construed as limiting the scope of the present invention, and the skilled engineer can make insubstantial modifications and variations of the present invention based on the above disclosure.