CN109401212B - Polyester composition, heat-shrinkable film and process for producing the same - Google Patents
Polyester composition, heat-shrinkable film and process for producing the same Download PDFInfo
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- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
- C08L67/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
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- C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
- C08J2367/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
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- C08J2467/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
- C08J2467/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
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- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
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- C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
- C08K3/24—Acids; Salts thereof
- C08K3/26—Carbonates; Bicarbonates
- C08K2003/265—Calcium, strontium or barium carbonate
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- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
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- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
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- C08L2201/06—Biodegradable
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2203/00—Applications
- C08L2203/16—Applications used for films
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- 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
- C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
- C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
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Abstract
The invention relates to the field of polymers, and discloses a polyester composition, a preparation method of the polyester composition, a heat-shrinkable film and a preparation method of the heat-shrinkable film. Specifically, the polyester composition comprises the following components by taking the total weight of the components as a reference: (1) 51-99 wt.% of polyester A; (2) 1 to 49% by weight of a polyester B. The heat-shrinkable film prepared from the polyester composition provided by the invention has high heat shrinkage rate, and the heat shrinkage rate can be changed in a large range, so that different requirements are met; in addition, the heat shrinkable film provided by the invention has proper heat sealing strength, smooth surface, good glossiness, degradability, repeated thermoplastic processing and recyclability.
Description
Technical Field
The invention relates to the field of polymers, in particular to a polyester composition, a preparation method of the polyester composition, a heat-shrinkable film and a preparation method of the heat-shrinkable film.
Background
A heat-shrinkable film is a film that can be significantly reduced in size upon heating. In the packaging industry, heat-shrinkable films are used very widely. The market scale of the Chinese heat-shrinkable film in 2006 is about 2 hundred million yuan RMB, and the growth rate is about 20 percent. Heat-shrinkable films need suitable shrinkage rates while preventing shrinkage behavior during storage.
Commonly used heat-shrinkable films: and (1) polyvinyl chloride film. It has low cost, low shrinkage temperature and wide shrinkage temperature range. Its disadvantages are high specific gravity, difficult recovery, poor low-temperature resistance, poor heat-sealing strength, brittle texture, generation of toxic gas during combustion, and serious environmental pollution, and the use of polyvinyl chloride heat-shrinkable films has been banned in Europe and Japan. (2) non-crosslinked polyethylene blown film. The polyethylene blown film has high impact strength and tearing strength, good thermal stability and low shrinkage. And (3) a polypropylene film. The film prepared by biaxial stretching polypropylene can be used as a heat-shrinkable film which has excellent transparency and moderate shrinkage, good stiffness, excellent heat-seal strength, easy processing, but is hard, poor in tear resistance and puncture resistance and not resistant to low temperature. And (4) polystyrene thin films. The polystyrene has low cost, is slightly higher than polyvinyl chloride, has simple recovery process, does not produce harmful gas during burning, and can replace polyvinyl chloride film in low-end products. It has a large shrinkage but is unstable and requires low-temperature storage. (5) PET and PETG films. Such films can achieve very high shrinkage in one direction (up to 75%) and very little shrinkage in the other direction (only 1%).
In recent years, composite films have been used in large quantities for heat-shrinkable films in addition to pure material films, mainly as follows: and (1) POF film. Such films are typically obtained by coextrusion of three polypropylene/polyethylene/polypropylene layers and blown up by the double bubble process. The film has higher heat sealing strength and mechanical strength, higher transparency and surface gloss and moderate shrinkage; and (2) multi-layer co-extrusion of a cross-linked polyethylene film. The film is prepared by performing irradiation crosslinking on a polyethylene film after the polyethylene film is blown up for the first time, and then blowing up again to a large extent so as to obtain a film with high shrinkage rate. But the film is crosslinked, cannot be recycled and thermoplastically processed again, and is not environment-friendly. From the above information, it can be seen that the heat-shrinkable film in market demand can have several key properties: large shrinkage, environmental protection (e.g., recyclable, harmless to combustion, etc.), high heat seal strength, good surface gloss, etc. However, no film with excellent performance is available in the market at present.
In addition, driven by the increasing severity of white pollution, the use of degradable plastics has been greatly encouraged in recent years, a large portion of which is the field of degradable films. But no mature solution for degradable heat shrinkable films exists in the market at present. One class of polyolefin films incorporating photodegradants is also claimed to be degradable films, as described in CN106519400a, but such films do not degrade completely, intelligently breaking the polyolefin into small pieces. The literature reports that the small blocks still have great pollution effect on soil or ocean. Only films made of degradable plastics can be completely biodegradable, and currently degradable films are based on hydroxyalkanoate, as described in CN103483789A, and on polylactic acid, as described in CN 103625061B. However, their properties do not meet the general properties of the general heat-shrinkable films as described above, thus limiting their widespread use.
Disclosure of Invention
The present invention has been made to overcome the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a polyester composition, a method for preparing the same, and a heat-shrinkable film and a method for preparing the same. The heat-shrinkable film prepared from the polyester composition provided by the invention has high heat shrinkage rate, and the heat shrinkage rate can be changed in a large range, so that different requirements are met; in addition, the heat shrinkable film provided by the invention has proper heat sealing strength, smooth surface, good glossiness, degradability, repeated thermoplastic processing and recyclability.
In order to achieve the above object, in a first aspect, the present invention provides a polyester composition, wherein the polyester composition comprises the following components, based on the total weight of the components:
(1) 51 to 99% by weight of a polyester A which is a copolymer comprising a repeating unit A represented by the formula (I) and a repeating unit B represented by the formula (II), wherein the content of the repeating unit A is 60 to 80 mol%, preferably 62 to 72 mol%, and the content of the repeating unit B is 20 to 40 mol%, preferably 28 to 38 mol%, based on the total number of moles of the repeating unit A and the repeating unit B in the polyester A,
wherein m1 is an integer of 2 to 4, n1 is an integer of 2 to 4, and m1 and n1 are the same or different, the polyester A has a weight average molecular weight of 50,000 to 900,000;
(2) 1 to 49% by weight of a polyester B which is a copolymer comprising a repeating unit C represented by the formula (III) and a repeating unit B represented by the formula (II), wherein the content of the repeating unit C is 81 to 99 mol%, preferably 85 to 97 mol%, and the content of the repeating unit B is 1 to 19 mol%, preferably 3 to 15 mol%, based on the total number of moles of the repeating unit C and the repeating unit B in the polyester B,
wherein m2 is an integer of 2 to 4, n2 is an integer of 2 to 4, and m2 and n2 are the same or different, and the polyester B has a weight average molecular weight of 50,000 to 900,000.
In a second aspect, the present invention also provides a method for preparing the polyester composition, the method comprising: polyester A and polyester B are blended, and the resulting mixture is subjected to extrusion granulation.
In a third aspect, the present invention also provides a heat-shrinkable film comprising the above polyester composition and/or the polyester composition obtained by the above production method.
In a fourth aspect, the present invention also provides a method for preparing a heat-shrinkable film, comprising: sequentially carrying out tape casting film forming, standing and stretching on the polyester composition to obtain a heat-shrinkable film; wherein the polyester composition is the polyester composition and/or the polyester composition obtained by the preparation method.
According to the invention, specific copolymers (polyester A and polyester B) are blended according to a specific proportion (the content of the polyester A is 51-99 wt%, and the content of the polyester B is 1-49 wt%), so that not only can a heat-shrinkable film with the heat shrinkage rate of more than 70% be obtained, but also a film with the heat shrinkage rate of 10% can be obtained, which shows that the heat shrinkage rate of the film can be changed in a large range through the adjustment of the formula and the polyester structure; in addition, the heat shrinkable film obtained by the invention has proper heat sealing strength (up to 11-19N/15 mm), smooth surface, good glossiness, degradability, repeated thermoplastic processing and recyclability, thus having obvious environmental protection advantage and industrial application prospect.
Detailed Description
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and these ranges or values should be understood to encompass values close to these ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
In a first aspect, the present invention provides a polyester composition, wherein the polyester composition comprises the following components, based on the total weight of the components:
(1) 51 to 99% by weight of a polyester A which is a copolymer comprising a repeating unit A represented by the formula (I) and a repeating unit B represented by the formula (II), wherein the content of the repeating unit A is 60 to 80 mol%, preferably 62 to 72 mol%, and the content of the repeating unit B is 20 to 40 mol%, preferably 28 to 38 mol%, based on the total number of moles of the repeating unit A and the repeating unit B in the polyester A,
wherein m1 is an integer of 2 to 4; n1 is an integer from 2 to 4, preferably 2; and m1 and n1 are the same or different; the weight average molecular weight of the polyester A is 50,000-900,000, preferably 100,000-500,000;
(2) 1 to 49% by weight of a polyester B which is a copolymer comprising a repeating unit C represented by the formula (III) and a repeating unit B represented by the formula (II), wherein the content of the repeating unit C is 81 to 99 mol%, preferably 85 to 97 mol%, and the content of the repeating unit B is 1 to 19 mol%, preferably 3 to 15 mol%, based on the total number of moles of the repeating unit C and the repeating unit B in the polyester B,
wherein m2 is an integer of 2 to 4; n2 is an integer from 2 to 4, preferably 2; and m2 and n2 are the same or different; the weight average molecular weight of the polyester B is 50,000 to 900,000, preferably 100,000 to 500,000.
In the present invention, m1 and m2 may be the same or different, and n1 and n2 may be the same or different. However, when m1 and m2 are the same and n1 and n2 are also the same, the content of the repeating unit B in the polyester A is different from that in the polyester B.
In a preferred case, the content of the repeating unit B in the polyester a is greater than the content of the repeating unit B in the polyester B.
In the present invention, the weight average molecular weight of the polymer is measured according to Gel Permeation Chromatography (GPC).
Preferably, the polyester composition comprises 60 to 90% by weight of polyester A and 10 to 40% by weight of polyester B. In the present invention, the composition of the polymer is determined by the amount of the raw materials charged.
In the present invention, the polyester a and the polyester B may be at least one of a random copolymer, an alternating copolymer, a block copolymer, and a graft copolymer, and preferably a random copolymer and/or a block copolymer. The sources of the polyester A and the polyester B are not particularly limited in the present invention, and can be obtained by means conventional in the art, can be obtained commercially, or can be prepared according to the method disclosed in CN100429256C in examples B13-B21. Specifically, the preparation method of the polyester A comprises the following steps:
(1) Reacting a monomer A and a monomer B in the presence of a first catalyst in an inert atmosphere;
(2) Reacting a monomer C and a monomer D in the presence of a first catalyst in an inert atmosphere;
(3) Reacting the reaction product obtained in the step (1) and the reaction product obtained in the step (2) in the presence of a second catalyst;
wherein the monomer A is butanediol; the monomer B is terephthalic acid and/or ester thereof, preferably at least one of terephthalic acid, dimethyl terephthalate and diethyl terephthalate; the monomer C is dihydric alcohol (especially saturated straight-chain dihydric alcohol) of C2-C4; the monomer D is a dibasic acid (especially a saturated straight-chain dibasic acid) of C4-C6; the first catalyst is at least one of tetrabutyl titanate, titanium dioxide, diethoxy titanium and zinc acetate, and tetrabutyl titanate is preferred; the second catalyst is at least one of lanthanum acetylacetonate, lanthanum trichloride, triphenoxy lanthanum and lanthanum propionate, and is preferably lanthanum acetylacetonate.
In the present invention, in step (1), the molar ratio of the monomer B to the first catalyst is 1:0.0001-0.02:0.0001-0.02, more preferably 1:0.001-0.003:0.001-0.003.
In the present invention, in the step (2), the molar ratio of the monomer D to the first catalyst is 1:0.0001-0.02:0.0001-0.02, more preferably 1:0.001-0.003:0.001-0.003.
In a preferred case, the molar ratio of the total amount of the first catalyst (sum of the amounts of the first catalyst used in step (1) and step (2)) to the amount of the second catalyst is 1:0.5-1.5, preferably 1:0.8-1.2.
In the present invention, the types of the respective reaction monomers can be adjusted correspondingly according to the composition and molecular weight of the target product, and the molecular weight of the product and the content of the respective repeating units in the product can be controlled by adjusting the amount and ratio of the charge.
In the present invention, in step (1), the temperature of the reaction is preferably 160 to 220 ℃; in the present invention, in step (2), the temperature of the reaction is preferably 160 to 220 ℃; in the present invention, in step (3), the temperature of the reaction is preferably 180 to 240 ℃.
In a preferred embodiment of the present invention, when m1 is 4, the preparation method of the polyester a comprises the steps of:
(S1) reacting butanediol and a monomer A' in the presence of a first catalyst in an inert atmosphere;
(S2) reacting the reaction product obtained in the step (S1) with a monomer B' in the presence of a second catalyst;
wherein A' is terephthalic acid and/or an ester thereof, preferably at least one of terephthalic acid, dimethyl terephthalate and diethyl terephthalate; the monomer B' is a dibasic acid (especially a saturated straight-chain dibasic acid) of C4-C6; the first catalyst and the second catalyst are as described above and will not be described in detail herein.
In the present invention, in step (S1), the molar ratio of the monomer a' to the first catalyst is 1:0.0001-0.02:0.0001-0.02, more preferably 1:0.001-0.003:0.001-0.003.
In a preferred case, the molar ratio of the amount of the first catalyst to the amount of the second catalyst is 1:0.5-1.5, preferably 1:0.8-1.2.
In the present invention, the types of the respective reaction monomers can be adjusted correspondingly according to the composition and molecular weight of the target product, and the molecular weight of the product and the content of the respective repeating units in the product can be controlled by adjusting the amount and ratio of the charge.
In the present invention, in step (S1), the temperature of the reaction is preferably 160 to 220 ℃; in the present invention, in the step (S2), the temperature of the reaction is preferably 180 to 240 ℃.
According to the present invention, the polyester B can be prepared according to the above-mentioned preparation method of the polyester A, wherein the types of the respective reaction monomers can be adjusted correspondingly according to the composition and molecular weight of the target product, and the molecular weight of the product and the content of the respective repeating units in the product can be controlled by adjusting the amount and ratio of the charged materials to obtain the polyester B.
According to the invention, the polyester composition may also contain auxiliary fillers; preferably, the content of the auxiliary filler is 0.1 to 20% by weight, more preferably 10 to 20% by weight, based on the total weight of the polyester composition.
According to the present invention, the auxiliary filler has the effects of accelerating the melt solidification of the composition, adjusting the mechanical strength of the composition, improving the flame retardancy and oxidation resistance of the composition, adjusting the color and gloss of the composition, and may be conventionally selected in the art, for example, the auxiliary filler may be selected from at least one of calcium carbonate, carbon black, talc, erucamide, titanium dioxide, iron oxide, metal carboxylate, metal phosphate, tetrabromobisphenol a, decabromodiphenyl ether, hexabromocyclododecane, low density polyethylene, polyphosphate, phosphite, hindered phenol, hindered amine, dibenzyl sorbitol and its derivatives, hyperbranched polyamide, and ethylene-methacrylic acid ionomer; preferably at least one of calcium carbonate, carbon black, erucamide, titanium dioxide, polyphosphate, low density polyethylene, and hyperbranched polyamide; more preferably at least two of calcium carbonate, carbon black, erucamide, titanium dioxide, tris (2,3-dibromopropyl) phosphate, low density polyethylene, and hyperbranched polyamide.
In a second aspect, the present invention also provides a method for preparing the above polyester composition, which comprises: the polyester A and the polyester B are blended, and the obtained mixture is extruded and granulated.
In the preparation method of the polyester composition of the present invention, the composition of the polyester a, the composition of the polyester B, and the amounts of the polyester a and the polyester B are as described above, and are not described herein again.
According to the present invention, the preparation method may further include: the blending is carried out in the presence of an auxiliary filler; preferably, the content of the auxiliary filler is 0.1 to 20% by weight, more preferably 10 to 20% by weight, based on the total weight of the polyester composition.
In the process for preparing the polyester composition of the present invention, the kind of the auxiliary filler is as described above and will not be described herein again.
In the present invention, the inventors have unexpectedly found during the research that: the polyester A has good compatibility with the polyester B, and therefore, a compatibilizer may not be added during blending. The compatibilizer is a substance conventionally used in the art to improve compatibility of blending raw materials, and may be, for example, at least one of PE-g-ST, PP-g-ST, ABS-g-MAH, PE-g-MAH, and PP-g-MAH.
According to the invention, the blending process can be carried out under stirring. In the present invention, the stirring conditions are not particularly limited as long as the raw materials can be uniformly mixed, and in a preferable case, the stirring speed is 10 to 150r/min, and the stirring time is 5 to 15min.
According to the present invention, the extrusion granulation process may be performed according to a conventional extrusion granulation method, for example, the extrusion granulation may be performed in a twin-screw extruder. In a preferred case, the temperature of the extrusion granulation is 80 to 220 ℃, preferably 110 to 180 ℃.
In a third aspect, the present invention also provides a heat-shrinkable film comprising, i.e., made from, the above-mentioned polyester composition and/or the polyester composition obtained by the above-mentioned production method. .
In the present invention, the thickness of the heat shrinkable film may be 5 to 1000 μm, and the heat shrinkage rate may be changed in a wide range by adjusting the formulation and the polyester structure, for example, the heat shrinkage rate of the heat shrinkable film is 10 to 80%, which may satisfy different requirements; and the heat-seal strength of the heat-shrinkable film is 11-19N/15mm, and the heat-shrinkable film has good degradability.
In a fourth aspect, the present invention also provides a method for preparing a heat-shrinkable film, comprising: sequentially carrying out tape casting film forming, standing and stretching on the polyester composition to obtain a heat-shrinkable film; wherein the polyester composition is the polyester composition and/or the polyester composition obtained by the preparation method.
According to the present invention, the process of casting film formation is not particularly limited, and may be performed on a casting machine, for example. Preferably, the cast film is formed at a temperature of from 80 ℃ to 220 ℃, preferably from 110 ℃ to 180 ℃.
In the present invention, the process of the standing is not particularly limited, and for example, the mixture may be left in a room temperature (25 ℃ C.) environment. Preferably, the standing time is 30 minutes to 20 days, preferably 4 to 24 hours.
In the present invention, the stretching may be unidirectional stretching or bidirectional stretching. In a preferred case, the stretching temperature is 40 to 150 ℃, preferably 60 to 120 ℃.
The present invention will be described in detail below by way of examples.
In the following examples and comparative examples, the weight average molecular weight of the polymer was measured using Gel Permeation Chromatography (GPC) with Tetrahydrofuran (THF) as a solvent on a Waters-208 (with a Waters 2410RI detector, 1.5mL/min flow rate, 30 ℃) instrument calibrated with styrene standards;
the composition of the polyester composition is determined by the raw material charge;
without being particularly specified, the polyester used in the present invention is prepared by itself according to the method disclosed in examples B13-B21 of CN100429256C, wherein the types of the reaction raw materials can be adjusted correspondingly according to the composition and molecular weight of the target product, and the molecular weight of the product and the content of each repeating unit in the product can be controlled by adjusting the feeding amount and the feeding ratio.
Example 1
This example illustrates a heat-shrinkable film and a method for making the same according to the present invention.
Under the condition of stirring (the stirring speed is 30r/min, the stirring time is 10 min), 2kg of terephthalic acid butanediol-succinic acid butanediol copolyester A (the weight-average molecular weight is 100,000, wherein the total mole number of a terephthalic acid butanediol repeating unit and a succinic acid butanediol repeating unit is taken as a reference, the content of the terephthalic acid butanediol repeating unit is 35 mol%), 1kg of terephthalic acid butanediol-succinic acid butanediol copolyester B (the weight-average molecular weight is 100,000, wherein the total mole number of the terephthalic acid butanediol repeating unit and the succinic acid butanediol repeating unit is taken as a reference, the content of the terephthalic acid butanediol repeating unit is 15 mol%), 0.5kg of calcium carbonate and 0.01kg of erucamide are mixed and then extruded, drawn, air-cooled and granulated by a double-screw extruder, wherein the temperature of each section from a feeding port to an extrusion port in the double-screw extruder is 170 ℃, 180 ℃, 190 ℃ and 190 ℃ in sequence. Polyester composition A1 was obtained.
The above pellets of the polyester composition A1 were cast by a casting machine at 150 ℃ to obtain a film having a thickness of 0.2 mm. The film was left standing at room temperature (25 ℃ C.) for 10 hours, and then stretched 5 times as long as it was at 60 ℃ on a uniaxial stretcher to obtain a heat-shrinkable film B1.
Example 2
This example illustrates a heat-shrinkable film and a method for making the same according to the present invention.
Under the condition of stirring (the stirring speed is 30r/min, the stirring time is 10 min), 1.8kg of terephthalic acid butanediol-succinic acid butanediol copolyester A (the weight-average molecular weight is 100,000, wherein the total mole number of a terephthalic acid butanediol repeating unit and a succinic acid butanediol repeating unit is taken as a reference, the content of the terephthalic acid butanediol repeating unit is 38 mol%), 1.2kg of terephthalic acid butanediol-succinic acid butanediol copolyester B (the weight-average molecular weight is 100,000, wherein the total mole number of the terephthalic acid butanediol repeating unit and the succinic acid butanediol repeating unit is taken as a reference, the content of the terephthalic acid butanediol repeating unit is 3 mol%), 0.5kg of calcium carbonate and 0.01kg of erucic acid amide are mixed and then extruded, drawn, air-cooled and granulated by a double-screw extruder, wherein the temperature of each section from a feeding hole to an extrusion hole in the double-screw extruder is 170 ℃, 180 ℃, 190 ℃ and 190 ℃. To obtain a polyester composition A2.
The above polyester composition A2 pellets were cast at 150 ℃ by a casting machine to obtain a film having a thickness of 0.2 mm. The film was left standing at room temperature (25 ℃ C.) for 10 hours, and then stretched at 60 ℃ C in a uniaxial stretcher to 4.5 times the original length to obtain a heat-shrinkable film B2.
Example 3
This example illustrates a heat-shrinkable film and a method for making the same according to the present invention.
Under the condition of stirring (the stirring speed is 30r/min, the stirring time is 10 min), 2.7kg of terephthalic acid butanediol-succinic acid butanediol copolyester A (the weight-average molecular weight is 100,000, wherein the content of the terephthalic acid butanediol repeating unit is 28 mol% based on the total molar number of the terephthalic acid butanediol repeating unit and the succinic acid butanediol repeating unit), 0.3kg of terephthalic acid butanediol-succinic acid butanediol copolyester B (the weight-average molecular weight is 100,000, wherein the content of the terephthalic acid butanediol repeating unit is 15 mol% based on the total molar number of the terephthalic acid butanediol repeating unit and the succinic acid butanediol repeating unit), 0.5kg of calcium carbonate and 0.01kg of erucamide are mixed and then extruded, drawn, air-cooled and granulated by a double-screw extruder, wherein the temperature of each section from a feed inlet to an extrusion outlet in the double-screw extruder is 170 ℃, 180 ℃, 190 ℃ and 190 ℃. Polyester composition A3 was obtained.
The above polyester composition A3 pellets were cast at 150 ℃ by a casting machine to obtain a film having a thickness of 0.2 mm. The film was left standing at room temperature (25 ℃ C.) for 10 hours, and then stretched 4 times as long as it was at 60 ℃ on a uniaxial stretcher to obtain a heat-shrinkable film B3.
Example 4
This example illustrates a heat-shrinkable film and a method for making the same according to the present invention.
Under the condition of stirring (the stirring speed is 30r/min, the stirring time is 10 min), 2.97kg of terephthalic acid butanediol-succinic acid butanediol copolyester A (the weight-average molecular weight is 100,000, wherein the total mole number of a terephthalic acid butanediol repeating unit and a succinic acid butanediol repeating unit is taken as the reference, the content of the terephthalic acid butanediol repeating unit is 40 mol%), 0.03kg of terephthalic acid butanediol-succinic acid butanediol copolyester B (the weight-average molecular weight is 100,000, wherein the total mole number of the terephthalic acid butanediol repeating unit and the succinic acid butanediol repeating unit is taken as the reference, the content of the terephthalic acid butanediol repeating unit is 20 mol%), 0.5kg of calcium carbonate and 0.01kg of erucic acid amide are mixed and then extruded, drawn, air-cooled and granulated by a double-screw extruder, wherein the temperature of each section from a feeding hole to an extrusion hole in the double-screw extruder is 170 ℃, 180 ℃, 190 ℃ and 190 ℃. Polyester composition A4 was obtained.
The above polyester composition A4 pellets were cast at 150 ℃ by a casting machine to obtain a film having a thickness of 0.2 mm. The film was left standing at room temperature (25 ℃ C.) for 10 hours, and then stretched 4 times as long as it was at 60 ℃ on a uniaxial stretcher to obtain a heat-shrinkable film B4.
Example 5
This example illustrates a heat-shrinkable film and a method for making the same according to the present invention.
Under the condition of stirring (the stirring speed is 30r/min, the stirring time is 10 min), 1.53kg of terephthalic acid butanediol-succinic acid butanediol copolyester A (the weight-average molecular weight is 100,000, wherein the total mole number of a terephthalic acid butanediol repeating unit and a succinic acid butanediol repeating unit is taken as a reference, the content of the terephthalic acid butanediol repeating unit is 20 mol%), 1.47kg of terephthalic acid butanediol-succinic acid butanediol copolyester B (the weight-average molecular weight is 100,000, wherein the total mole number of the terephthalic acid butanediol repeating unit and the succinic acid butanediol repeating unit is taken as a reference, the content of the terephthalic acid butanediol repeating unit is 1 mol%), 0.5kg of calcium carbonate and 0.5kg of erucic acid amide are mixed and then extruded, drawn, air-cooled and granulated by a double-screw extruder, wherein the temperature of each section from a feeding hole to an extrusion hole in the double-screw extruder is 170 ℃, 180 ℃, 190 ℃ and 190 ℃. Polyester composition A5 was obtained.
The above polyester composition A5 pellets were cast at 150 ℃ by a casting machine to obtain a film having a thickness of 0.2 mm. The film was left standing at room temperature (25 ℃ C.) for 10 hours, and then stretched at 60 ℃ C in a uniaxial stretcher to 1.5 times the original length to obtain a heat-shrinkable film B5.
Example 6
This example illustrates a heat-shrinkable film and a method for making the same according to the present invention.
The procedure is as in example 1, except that polyester A is a butylene terephthalate-butylene adipate copolyester (weight average molecular weight 100,000, wherein the content of butylene terephthalate repeat units is 35 mole%, based on the total moles of butylene terephthalate repeat units and butylene adipate repeat units); polyester B was a butylene terephthalate-butylene adipate copolyester (weight average molecular weight 100,000, wherein the content of butylene terephthalate repeat units was 15 mole%, based on the total number of moles of butylene terephthalate repeat units and butylene adipate repeat units). Polyester composition A6 and heat-shrinkable film B6 were obtained.
Example 7
This example illustrates a heat-shrinkable film and a method for making the same according to the present invention.
The procedure was followed as in example 1, except that polyester A was butylene terephthalate-ethylene succinate copolyester (weight average molecular weight 200,000, wherein the content of butylene terephthalate repeat units was 35 mol%, based on the total number of moles of butylene terephthalate repeat units and ethylene succinate repeat units); the polyester B was a butylene terephthalate-ethylene succinate copolyester (having a weight average molecular weight of 200,000, wherein the content of butylene terephthalate repeating units was 15 mol%, based on the total number of moles of butylene terephthalate repeating units and ethylene succinate repeating units). Polyester composition A7 and heat-shrinkable film B7 were obtained.
Example 8
This example illustrates a heat-shrinkable film and a method for making the same according to the present invention.
The procedure is as in example 1, except that polyester A is a butylene terephthalate-butylene glycol adipate copolyester (weight average molecular weight 500,000, wherein the content of butylene terephthalate repeat units is 35 mole%, based on the total moles of butylene terephthalate repeat units and butylene glycol oxalate repeat units); the polyester B was butylene terephthalate-ethylene succinate copolyester (weight average molecular weight 500,000, wherein the content of butylene terephthalate repeat units was 15 mol%, based on the total number of moles of butylene terephthalate repeat units and ethylene succinate repeat units). Polyester composition A8 and heat-shrinkable film B8 were obtained.
Example 9
This example illustrates a heat-shrinkable film and a method for making the same according to the present invention.
The procedure of example 1 was followed except that 0.2kg of carbon black and 0.2kg of titanium dioxide were used instead of 0.5kg of calcium carbonate and 0.01kg of erucamide used in example 1. Polyester composition A9 and heat-shrinkable film B9 were obtained.
Example 10
This example illustrates a heat-shrinkable film and a method for making the same according to the present invention.
The procedure of example 1 was followed except that 0.5kg of calcium carbonate and 0.01kg of erucamide were not added. Polyester composition A10 and heat-shrinkable film B10 were obtained.
Comparative example 1
The procedure of example 1 was followed except that the polyester A of example 1 was directly formed into a film DB1 without the blending process with the polyester B of example 1.
Comparative example 2
The procedure of example 1 was followed except that the polyester B of example 1 was directly formed into a film DB2 without the blending process with the polyester A of example 1.
Comparative example 3
Film DB3 was prepared according to the procedure of example 1, except that the same weight of polybutylene terephthalate (available from DuPont under the trademark Crastin SC164NC010, the same applies hereinafter) was used instead of the polyester A used in example 1.
Comparative example 4
Film DB4 was prepared following the procedure of example 1, except that the same weight of polybutylene terephthalate was used instead of the polyester B used in example 1.
Comparative example 5
Film DB5 was prepared according to the procedure of example 1, except that the same weight of polybutylene succinate (available from BASF corporation under the designation 1111HTA4, the same applies hereinafter) was used in place of the polyester A used in example 1.
Comparative example 6
Film DB6 was prepared according to the method of example 1, except that the same weight of polybutylene succinate was used instead of the polyester B used in example 1.
Comparative example 7
The procedure of example 1 was followed, except that the amount of polyester A was 1kg and the amount of polyester B was 2kg, to obtain film DB7.
Comparative example 8
The procedure is as in example 1, except that 1.5kg of polyester A and 1.5kg of polyester B are used to prepare DB8 film.
Comparative example 9
The procedure is as in example 1, except that the polybutylene terephthalate is directly formed into film DB9.
Comparative example 10
The procedure of example 1 was followed, except that polybutylene succinate was directly used as film DB10.
Test examples 1 to 20
Testing the thermal shrinkage rate: the films obtained in examples 1 to 10 and comparative examples 1 to 10 were each tested for heat shrinkage (%);
testing of heat seal strength: after wrapping with 25 μm Teflon on a Brugger Munchen HSG-C heat sealer, each two layers of the respective films were heat-sealed at 90 ℃ for 2s under a pressure of 100N, and then the heat-seal strengths (N/15 mm) of the films obtained in examples 1 to 10 and comparative examples 1 to 10 were respectively measured by an Instron 5965 tensile tester (50 mm/min speed) in accordance with the test method of QB/T2358-1998;
biodegradation test: the films obtained in examples 1 to 10 and comparative examples 1 to 10 were each tested for biodegradation by the following method, specifically, 18g of compost (2 months old) from Beijing south China compost factory was used, 3g of film to be tested was added, and an appropriate amount of distilled water was added thereto, mixed and stirred appropriately, and then left at room temperature (25 ℃). Whether the weight loss is more than 50% in 3 months is taken as a standard for judging whether the biodegradation is qualified or not.
The results of the above tests are shown in table 1.
In addition, the heat-shrinkable films prepared in examples 1 to 10 were not significantly changed for at least one year in a clean environment of normal temperature and humidity, and were significantly degraded only in the case of soil, nutrient-rich soil, or compost.
TABLE 1
Note: "a" indicates that the unidirectional stretching process can not be completed after the film is formed by casting so as to obtain a complete heat-shrinkable film;
"b" indicates that film casting cannot be performed;
"c" indicates that the film forming property is poor, the film is not easy to control and break in the casting process;
"d" indicates that the stretching process is not easy to control and easy to break the membrane;
"-" indicates no measurement.
As can be seen from the results of Table 1 above, the invention can obtain not only a heat-shrinkable film with a heat shrinkage of more than 70% but also a film with a heat shrinkage of 10% by blending specific copolymers (polyester A and polyester B) according to specific blending ratios (polyester A content of 51-99 wt%, polyester B content of 1-49 wt%), which shows that the invention can change the heat shrinkage of the film in a large range by adjusting the formulation and the polyester structure; in addition, the heat shrinkable film obtained by the invention has proper heat sealing strength (up to 11-19N/15 mm), smooth surface, good glossiness, degradability, repeated thermoplastic processing and recyclability, thus having obvious environmental protection advantage and industrial application prospect.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.
Claims (22)
1. A heat-shrinkable film characterized by comprising a polyester composition, based on the total weight of the components, comprising the following components:
(1) 60 to 90 wt% of a polyester A which is a copolymer comprising a repeating unit A represented by the formula (I) and a repeating unit B represented by the formula (II) and has a content of the repeating unit A of 62 to 72 mol% and a content of the repeating unit B of 28 to 38 mol% based on the total number of moles of the repeating unit A and the repeating unit B in the polyester A,
Wherein m1 is an integer of 2 to 4, n1 is an integer of 2 to 4, and m1 and n1 are the same or different, the polyester A has a weight average molecular weight of 50,000 to 900,000;
(2) 10 to 40% by weight of a polyester B which is a copolymer comprising a repeating unit C represented by the formula (III) and a repeating unit B represented by the formula (II), wherein the content of the repeating unit C is 85 to 97 mol% and the content of the repeating unit B is 3 to 15 mol% based on the total number of moles of the repeating unit C and the repeating unit B in the polyester B,
Wherein m2 is an integer of 2 to 4, n2 is an integer of 2 to 4, and m2 and n2 are the same or different, and the polyester B has a weight average molecular weight of 50,000 to 900,000.
2. The heat-shrinkable film according to claim 1, wherein, in formula (I), m1 is an integer of 2 to 4, and n1 is 2.
3. The heat-shrinkable film of claim 1, wherein the polyester a has a weight average molecular weight of 100,000 to 500,000.
4. The heat-shrinkable film according to claim 1, wherein in formula (II), m2 is an integer of 2 to 4, and n2 is 2.
5. The heat-shrinkable film of claim 1, wherein the polyester B has a weight-average molecular weight of 100,000 to 500,000.
6. The heat-shrinkable film of claim 1, wherein the polyester composition further comprises an auxiliary filler.
7. The heat-shrinkable film of claim 6, wherein the content of the auxiliary filler is 0.1 to 20% by weight, based on the total weight of the polyester composition.
8. The heat-shrinkable film of claim 7, wherein the content of the auxiliary filler is 10 to 20% by weight, based on the total weight of the polyester composition.
9. The heat-shrinkable film of claim 6, wherein the auxiliary filler is selected from at least one of calcium carbonate, carbon black, talc, erucamide, titanium dioxide, iron oxide, metal carboxylate, metal phosphate, tetrabromobisphenol A, decabromodiphenyl ether, hexabromocyclododecane, low density polyethylene, polyphosphate, phosphite, hindered phenol, hindered amine, dibenzylsorbitol and its derivatives, hyperbranched polyamide, and ethylene-methacrylic ionomer.
10. The heat-shrinkable film of claim 9, wherein the auxiliary filler is selected from at least one of calcium carbonate, carbon black, erucamide, titanium dioxide, tris (2,3-dibromopropyl) phosphate, low density polyethylene, and hyperbranched polyamide.
11. The heat-shrinkable film of any one of claims 1 to 10, wherein the polyester composition is prepared by a method comprising: polyester A and polyester B are blended, and the resulting mixture is subjected to extrusion granulation.
12. The heat-shrinkable film of claim 11, wherein the blending is performed without the addition of a compatibilizer.
13. The heat-shrinkable film of claim 11, wherein the temperature of the extrusion pelletization is 80 to 220 ℃.
14. The heat-shrinkable film of claim 13, wherein the temperature of the extrusion pelletization is 110 to 180 ℃.
15. A method for preparing a heat-shrinkable film according to any one of claims 1 to 14, comprising: the polyester composition is subjected to film casting, standing and stretching in sequence to obtain the heat shrinkable film.
16. A producing method according to claim 15, wherein said cast film is formed at a temperature of 80 to 220 ℃.
17. A producing method according to claim 15, wherein said cast film is formed at a temperature of 110 to 180 ℃.
18. The method of claim 15, wherein the standing time is 30 minutes to 20 days.
19. The production method according to claim 18, wherein the standing time is 4 to 24 hours.
20. The production method according to claim 15, wherein the stretching is unidirectional stretching or bidirectional stretching.
21. The production method according to claim 15, wherein the temperature of the drawing is 40 to 150 ℃.
22. The production method according to claim 21, wherein the temperature of the drawing is 60 to 120 ℃.
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| CN201710703232.7A CN109401212B (en) | 2017-08-16 | 2017-08-16 | Polyester composition, heat-shrinkable film and process for producing the same |
| US16/343,711 US11466151B2 (en) | 2016-10-21 | 2017-10-20 | Polyester composition, preparation method therefor and application thereof |
| EP17862862.4A EP3530694A4 (en) | 2016-10-21 | 2017-10-20 | Polyester composition, preparation method therefor and application thereof |
| JP2019520899A JP2020502288A (en) | 2016-10-21 | 2017-10-20 | Polyester composition, its production method and its application |
| PCT/CN2017/107106 WO2018072746A1 (en) | 2016-10-21 | 2017-10-20 | Polyester composition, preparation method therefor and application thereof |
| CA3040988A CA3040988A1 (en) | 2016-10-21 | 2017-10-20 | Polyester composition, preparation method therefor and application thereof |
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| CN102812084A (en) * | 2010-03-24 | 2012-12-05 | 巴斯夫欧洲公司 | Method for producing foil |
| CN102869723A (en) * | 2010-03-24 | 2013-01-09 | 巴斯夫欧洲公司 | Process for producing cling films |
| TW201714730A (en) * | 2015-08-06 | 2017-05-01 | Nitto Denko Corp | Polyester film |
| CN107974052A (en) * | 2016-10-21 | 2018-05-01 | 中国石油化工股份有限公司 | A kind of polymer blend and its preparation method and application |
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|---|---|---|---|---|
| CN102812084A (en) * | 2010-03-24 | 2012-12-05 | 巴斯夫欧洲公司 | Method for producing foil |
| CN102869723A (en) * | 2010-03-24 | 2013-01-09 | 巴斯夫欧洲公司 | Process for producing cling films |
| TW201714730A (en) * | 2015-08-06 | 2017-05-01 | Nitto Denko Corp | Polyester film |
| CN107974052A (en) * | 2016-10-21 | 2018-05-01 | 中国石油化工股份有限公司 | A kind of polymer blend and its preparation method and application |
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