阅读说明：本技术 制备高强度高模量的聚烯烃薄膜的设备及方法和高强度高模量的聚烯烃薄膜 (Apparatus and method for preparing high-strength high-modulus polyolefin film and high-strength high-modulus polyolefin film ) 是由 郅立鹏 刘鹏 吕展飞 孙昌峰 徐阳 杨波 于 2019-11-19 设计创作，主要内容包括：本发明提供了一种制备高强度高模量的聚烯烃薄膜的设备及方法和高强度高模量的聚烯烃薄膜。制备高强度高模量的聚烯烃薄膜的设备,包括顺次配置的熔融挤出机、冷却系统、拉伸系统和萃取系统。制备高强度高模量的聚烯烃薄膜的方法,包括：将聚烯烃树脂和溶剂在熔融挤出机中熔融塑化,经模头挤出后在定型辊和冷却槽处实现热致相分离得到铸片,然后经多级组合的拉伸系统拉伸、萃取系统萃取以及后处理得到所述高强度高模量的聚烯烃薄膜。高强度高模量的聚烯烃薄膜,使用所述的制备高强度高模量的聚烯烃薄膜的方法制得。使用本申请提供的设备和方法制得的聚烯烃薄膜,实现超高倍率拉伸,得到的薄膜具有良好的均匀性、强度、热收缩性能。(The invention provides equipment and a method for preparing a high-strength high-modulus polyolefin film and the high-strength high-modulus polyolefin film. The equipment for preparing the high-strength high-modulus polyolefin film comprises a melt extruder, a cooling system, a stretching system and an extraction system which are sequentially arranged. A method of making a high strength, high modulus polyolefin film comprising: melting and plasticizing polyolefin resin and a solvent in a melting extruder, extruding the mixture by a die head, realizing thermal phase separation at a setting roller and a cooling tank to obtain a cast sheet, and then stretching by a multi-stage combined stretching system, extracting by an extraction system and post-treating to obtain the high-strength high-modulus polyolefin film. A high-strength high-modulus polyolefin film, which is produced by using the method for producing a high-strength high-modulus polyolefin film. The polyolefin film prepared by the equipment and the method provided by the application realizes ultrahigh-rate stretching, and the obtained film has good uniformity, strength and heat shrinkage performance.)

1. An apparatus for preparing a high-strength high-modulus polyolefin film, comprising a melt extruder, a cooling system, a stretching system and an extraction system, which are arranged in sequence;

the stretching system comprises a plurality of transverse stretching machines for transversely stretching the stretched objects, longitudinal stretching machines for longitudinally stretching the stretched objects, splitting machines for splitting the stretched objects and bidirectional synchronous stretching machines for bidirectionally stretching the stretched objects.

2. The apparatus for manufacturing a high strength and high modulus polyolefin film according to claim 1, wherein the cooling system comprises a backup roll, a setting roll, a cooling roll and a cooling tank;

the setting roller sets up the backup roller with between the chill roll, the backup roller is used for coming from the fuse-element laminating of melting extruder's die head is in the surface of setting roller, the lower part setting of setting roller is in the cooling bath, the chill roll is used for cooling the cast sheet that the setting roller handled and obtains.

3. The apparatus for manufacturing a high-strength high-modulus polyolefin film according to claim 1, wherein the stretching system comprises the longitudinal stretcher, the transverse stretcher, the slitting machine and the biaxial synchronous stretcher, which are sequentially arranged; the splitting machine is used for splitting the film obtained by stretching through the transverse stretching machine.

4. The apparatus for manufacturing a high strength and high modulus polyolefin film according to claim 1, further comprising a turning device disposed after said slitting machine;

preferably, the bidirectional synchronous drawing machine is provided in plurality;

preferably, 3 biaxial synchronous stretching machines are stacked in the height direction;

preferably, the bidirectional synchronous stretcher is provided with a heating oven and a cooling oven, the temperature precision of the heating oven is +/-0.5 ℃, and the wind speed uniformity is +/-1 m/s.

5. The apparatus for preparing a high strength and high modulus polyolefin film according to any one of claims 1 to 4, wherein the extraction system comprises one or more sets of extraction tanks, each set of extraction tanks having a plurality of sets of drawing rolls and ultrasonic wave generating means disposed therein.

6. A method of making a high strength, high modulus polyolefin film comprising:

melting and plasticizing polyolefin resin and a solvent in a melting extruder, extruding the mixture through a die head, realizing thermally induced phase separation in a setting roller and a cooling tank to obtain a cast sheet, and then stretching the cast sheet through a multi-stage combined stretching system, extracting the cast sheet through an extraction system and performing post-treatment to obtain the high-strength high-modulus polyolefin film.

7. The method of claim 6, wherein the melt extruded from the die has a thickness of 2mm to 10 mm.

8. The method of claim 6, wherein the stretching system stretches the polyolefin film by a method comprising:

sequentially carrying out longitudinal stretching by 1-10 times, transverse stretching by 1-10 times and bidirectional synchronous stretching by (1-10) × (1-10) times; or the like, or, alternatively,

sequentially carrying out longitudinal stretching by 1-10 times and transverse stretching by 1-10 times, and repeatedly carrying out longitudinal stretching by 1-10 times and transverse stretching by 1-10 times for one time; or the like, or, alternatively,

two independent bidirectional synchronous stretching (1-10) times are carried out in succession; or the like, or, alternatively,

sequentially carrying out bidirectional synchronous stretching (1-10) × (1-10) times, longitudinal stretching 1-10 times and transverse stretching 1-10 times.

9. The method for preparing a high strength and high modulus polyolefin film according to any one of claims 6 to 8, wherein the post-treatment comprises drying, cross-hole-expanding stretching, cross-longitudinal bidirectional retraction treatment and heat setting which are sequentially performed;

preferably, the extraction is carried out without cutting off the drawn scrap in advance.

10. A high-strength high-modulus polyolefin film, which is obtained by the method for producing a high-strength high-modulus polyolefin film according to any one of claims 6 to 9;

preferably, the high-strength high-modulus polyolefin film has a thickness of 2-100 μm and an air permeability of 10-300s/in²100cc, tensile strength of 300-2000MPa, specific puncture strength of 50-300 gf/mum, porosity of 25-75%, and modulus of 2 GPa-30 GPa.

Technical Field

The invention relates to the field of polyolefin films, in particular to equipment and a method for preparing a high-strength high-modulus polyolefin film and the high-strength high-modulus polyolefin film.

Background

The wet lithium ion battery film is one of important component materials which are inevitably adopted in the current liquid lithium ion batteries, especially power batteries and high-grade 3C digital batteries. The polyolefin film has the advantages of low cost and high strength, and has the advantage of cost performance compared with the traditional material.

The traditional method for preparing the wet-process polyolefin film adopts the processes of plasticizing, extruding and casting sheets, single asynchronous or synchronous stretching, extracting and drying, secondary transverse drawing and shaping and rolling. In order to ensure the effect of cold extraction after plasticizing extrusion, the thickness of a cast sheet is not more than 2mm generally; the double-direction (MD/TD) magnification of single asynchronous stretching or synchronous stretching double-direction stretching does not exceed 10/10 times.

Disclosure of Invention

The present invention has been made to solve the above problems by providing an apparatus and a method for preparing a high-strength high-modulus polyolefin film, and a high-strength high-modulus polyolefin film.

In order to achieve the above purpose, the invention adopts the following technical scheme:

an apparatus for preparing a high-strength high-modulus polyolefin film, comprising a melt extruder, a cooling system, a stretching system and an extraction system, which are arranged in sequence;

the stretching system comprises a plurality of transverse stretching machines for transversely stretching the stretched objects, longitudinal stretching machines for longitudinally stretching the stretched objects, splitting machines for splitting the stretched objects and bidirectional synchronous stretching machines for bidirectionally stretching the stretched objects.

Through multi-stage stretching and slitting, the problem caused by the fact that the film sags under the action of gravity in the stretching process is solved, the problem that the stretching multiplying power of a single set of synchronous bidirectional stretching equipment or a single set of asynchronous stretching equipment is limited is solved, the maximum regional stretching multiplying power of 100 x 100 times is realized, and the film with high strength and large modulus is obtained.

Preferably, the apparatus for preparing the high-strength high-modulus polyolefin film further comprises a secondary transverse stretching system for reaming retraction, a heat setting system and the like.

Preferably, the cooling system comprises a backup roller, a shaping roller, a cooling roller and a cooling tank;

the setting roller sets up the backup roller with between the chill roll, the backup roller is used for coming from the fuse-element laminating of melting extruder's die head is in the surface of setting roller, the lower part setting of setting roller is in the cooling bath, the chill roll is used for cooling the cast sheet that the setting roller handled and obtains.

The cooling effect of the cast piece cooling system on the cast piece with large thickness is poor, so that the heat history difference of the front surface and the back surface of the film is large, and further the performance difference is large; because the heat transfer coefficient of the cast sheet is low, when the cast sheet is thick, if a forced cooling measure is not taken on the reverse side, the cooling speed of the reverse side is too low to form large platelets and even spherulites, and the performance difference of the film is amplified when the film is formed by stretching in the next step.

Preferably, the stretching system comprises the longitudinal stretcher, the transverse stretcher, the splitting machine and the bidirectional synchronous stretcher which are arranged in sequence; the splitting machine is used for splitting the film obtained by stretching through the transverse stretching machine.

The film width is large after the primary stretching, and the film needs to be cut to realize large transverse drawing multiplying power when the secondary stretching is carried out.

Preferably, the splitting machine further comprises a steering device, wherein the steering device is arranged behind the splitting machine;

preferably, the bidirectional synchronous drawing machine is provided in plurality;

preferably, 3 biaxial synchronous stretching machines are stacked in the height direction;

preferably, the bidirectional synchronous stretcher is provided with a heating oven and a cooling oven, the temperature precision of the heating oven is +/-0.5 ℃, and the wind speed uniformity is +/-1 m/s.

Need follow the equipment center and get into when cutting the back and carrying out the secondary drawing, traditional equipment processing technology can't realize that the film gets into a plurality of second grade elongators side by side, and this application turns to the device through setting up, turns to many times the film after will cutting, makes it get into the second grade elongator smoothly. In order to reduce the occupied area, the bidirectional synchronous stretcher can also be designed into a multilayer layout structure. The temperature precision and the wind speed uniformity of the heating oven are controlled, so that the uniformity of the film in stretching can be ensured.

Optionally, the extraction system includes one or more groups of extraction tanks, and each group of extraction tank is provided with a plurality of groups of drafting rollers and ultrasonic wave generation devices.

The multiple groups of drafting rollers are arranged, so that multiple layers of films can be simultaneously introduced into a single extraction tank, the simultaneous configuration of multiple extraction tanks is avoided, and the equipment investment and the factory building investment are reduced.

A method of making a high strength, high modulus polyolefin film comprising:

melting and plasticizing polyolefin resin and a solvent in a melting extruder, extruding the mixture through a die head, realizing thermally induced phase separation in a setting roller and a cooling tank to obtain a cast sheet, and then stretching the cast sheet through a multi-stage combined stretching system, extracting the cast sheet through an extraction system and performing post-treatment to obtain the high-strength high-modulus polyolefin film.

Preferably, the melt extruded by the die has a thickness of 2mm to 10 mm.

The large-thickness melt can obtain a large-thickness cast sheet, so that the film can be stretched at a large magnification, and excellent performances such as high strength and high modulus can be obtained.

Preferably, the stretching system stretches in a manner that includes:

sequentially carrying out longitudinal stretching by 1-10 times, transverse stretching by 1-10 times and bidirectional synchronous stretching by (1-10) × (1-10) times; or the like, or, alternatively,

sequentially carrying out longitudinal stretching by 1-10 times and transverse stretching by 1-10 times, and repeatedly carrying out longitudinal stretching by 1-10 times and transverse stretching by 1-10 times for one time; or the like, or, alternatively,

two independent bidirectional synchronous stretching (1-10) times are carried out in succession; or the like, or, alternatively,

sequentially carrying out bidirectional synchronous stretching (1-10) × (1-10) times, longitudinal stretching 1-10 times and transverse stretching 1-10 times.

The formed cast sheet needs to be stretched at ultrahigh multiplying power in the longitudinal and transverse product relationship by different combination methods of longitudinal stretching, transverse stretching and longitudinal and transverse synchronous stretching. Simultaneous stretching in both directions (1-10) × (1-10) times means 1-10 times in the transverse direction and 1-10 times in the longitudinal direction.

Optionally, the post-treatment comprises drying, transverse reaming and stretching, transverse and longitudinal bidirectional retraction treatment and heat setting which are sequentially performed;

preferably, the extraction is carried out without cutting off the drawn scrap in advance.

The transverse reaming and stretching can ensure that the film has proper porosity; the transverse and longitudinal bidirectional retraction treatment and the heat setting are carried out, the traditional transverse unidirectional retraction treatment method is abandoned, the longitudinal direction and the transverse direction of the membrane material are simultaneously retracted, and the bidirectional heat shrinkage stability is improved; when extraction drying is carried out, the stretching rim charge is not cut off in advance, the transverse shrinkage of the film in the extraction process is inhibited through the larger tensile force of the thick rim charge, and the consistency and the safety and the reliability of the lithium ion battery are seriously influenced because the problems of transverse extreme increase, poor uniformity and the like of the film caused by the extraction shrinkage.

A high-strength high-modulus polyolefin film, which is produced by the method for producing a high-strength high-modulus polyolefin film;

preferably, the high-strength high-modulus polyolefin film has a thickness of 2 to 100 μm, an air permeability of 10 to 300s/in2 × 100cc, a tensile strength of 300-2000MPa, a specific puncture strength of 50 to 300gf/μm, a porosity of 25 to 75%, and a modulus of 2GPa to 30 GPa.

Compared with the prior art, the invention has the beneficial effects that:

the cooling system and the multistage stretcher are arranged, so that high-magnification stretching is realized; according to the method provided by the application, the regional stretching multiple can be greatly improved to 10000 times, the orientation, crystallization and fine denier and specific strength of microscopic fibers of the film material are greatly improved, the breaking elongation of the film material is reduced, and the polyolefin film material with ultrahigh strength and ultrahigh modulus is formed.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 shows a schematic diagram of a cooling system provided by an embodiment;

FIG. 2 shows a schematic view of a longitudinal stretcher provided by an embodiment;

FIG. 3 shows a schematic view of a transverse stretcher provided by an embodiment;

FIG. 4 shows a schematic view of a slitting machine and a steering apparatus provided by an embodiment;

FIG. 5 shows a schematic diagram of a biaxial synchronous stretching machine provided by an embodiment;

FIG. 6 shows a schematic diagram of an extraction cell provided by an embodiment;

FIG. 7 is a scanning electron micrograph of a cross section of the cast slab on the roll side provided in comparative example 2;

FIG. 8 shows a scanning electron micrograph of a cross section of the film provided in comparative example 2;

FIG. 9 is a scanning electron micrograph of a cross section of the cast slab on the roll side provided in comparative example 3;

fig. 10 shows a scanning electron micrograph of a cross section of the thin film provided in comparative example 3.

Description of the main element symbols:

1-backing roll; 2-a shaping roller; 3-a chill roll; 4-a cooling tank; 5-a die head; 6-preheating roller; 7-a stretching roller; 8-a shaping roller of a longitudinal stretcher; 9-splitting machine; 10-heating the oven; 11-cooling the oven; 12-an extraction tank; 13-a drawing roll; 14-an ultrasonic wave generating device; 15-a steering device; 16-biaxial synchronous stretching machine.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

The terms as used herein:

"prepared from … …" is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of … …" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of … …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when the range "1 ~ 5" is disclosed, the ranges described should be construed to include the ranges "1 ~ 4", "1 ~ 3", "1 ~ 2 and 4 ~ 5", "1 ~ 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

In these examples, the parts and percentages are by mass unless otherwise indicated.

"part by mass" means a basic unit of measure indicating a mass ratio of a plurality of components, and 1 part may represent any unit mass, for example, 1g or 2.689 g. If we say that the part by mass of the component A is a part by mass and the part by mass of the component B is B part by mass, the ratio of the part by mass of the component A to the part by mass of the component B is a: b. alternatively, the mass of the A component is aK and the mass of the B component is bK (K is an arbitrary number, and represents a multiple factor). It is unmistakable that, unlike the parts by mass, the sum of the parts by mass of all the components is not limited to 100 parts.

"and/or" is used to indicate that one or both of the illustrated conditions may occur, e.g., a and/or B includes (a and B) and (a or B).