Modified copolyester material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of polyester materials, in particular to a modified copolyester material as well as a preparation method and application thereof. According to the preparation method of the modified copolyester material, the modified monomers are added for copolymerization, so that the modified copolyester material has excellent properties such as high transparency, high toughness, high strength, high modulus and solvent resistance, and meanwhile, the polyester material is firm in bonding and is not easy to deform, layer and the like in a hot-pressing compounding process.

Description

Technical Field

[0001] The invention relates to the technical field of polyester materials, and in particular to a modified copolyester material and a preparation method and application thereof. Background Art

[0002] Card-based polyester material for certificates is a material widely used in certificate production. It has good physical and mechanical properties, chemical resistance, airtightness and low temperature resistance, making it an ideal choice for making important certificates such as identity cards, passports, and driver's licenses.

[0003] In the prior art, CN112760740A discloses a bio-based 2,5-furandicarboxylic acid-based copolyester fiber and its preparation method and application. 12 -C 20 The diol ether composition is polymerized to form a 2,5-furandicarboxylic acid-based copolyester, and the prepared fiber has a higher tensile strength, breaking through the performance bottleneck of low tensile strength of conventional copolyester fibers. CN108130611A discloses a high-stretch and low-shrink polyester industrial yarn and a preparation method thereof. The introduction of branched diols in polyester reduces the cyclic oligomers produced in the side reactions of polyester, reduces the phenomenon of fiber breakage and uneven fiber thickness, reduces the influence of cyclic oligomers on the mechanical properties of the fiber such as breaking strength and elongation at break, and improves the quality of the obtained fiber. CN108048940A discloses a soft polyester fiber and a preparation method thereof. The molecular chain of the modified polyester includes a terephthalic acid segment, an ethylene glycol segment and an adipic acid segment. The adipic acid segment is a relatively long fatty chain, which will reduce the rigidity of the obtained polyester and improve its toughness. CN102757550B discloses a preparation method of a 1,6-hexanediol-modified polyester for heat shrinkable film. In addition to the various mechanical properties of ordinary polyester, polyester modified with 1,6-hexanediol has higher tensile properties than ordinary polyester.

[0004] At present, the existing technology mainly prepares copolyesters with excellent mechanical properties by adding monomers containing rigid groups or flexible fatty chains for polymerization. After the modified copolymerization reaction, the strength or toughness is significantly improved, but it is difficult to have both. At the same time, the obtained copolyester has a poor hue, low reaction activity during the polymerization process, and high requirements for catalysts.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The first object of the present invention is to provide a method for preparing a modified copolyester material, by adding a modified monomer for copolymerization, so that the modified copolyester material has excellent properties such as high transparency, high toughness, high strength, high modulus and solvent resistance.

[0007] The second object of the present invention is to provide a modified copolyester material as described above, which has excellent properties such as high transparency, high toughness, high strength, high modulus and solvent resistance. At the same time, the polyester material is firmly bonded during the hot pressing composite process and is not prone to deformation, delamination and the like.

[0008] The third object of the present invention is to provide the use of the modified copolyester material as described above, which is convenient for molding and printing as a card-based material and can be used for the production of documents with higher quality requirements.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0010] A method for preparing a modified copolyester material comprises the following steps:

[0011] The dibasic acid, the first diol, the second diol and the modified monomer are mixed and subjected to an esterification reaction, after the esterification reaction is completed, a catalyst is added and a polycondensation reaction is carried out, and after the polycondensation reaction is completed, the modified copolyester material is obtained;

[0012] The dibasic acid includes terephthalic acid, the first diol includes ethylene glycol, the second diol includes 1,4-cyclohexanedimethanol or neopentyl glycol, and the modified monomer includes at least one of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, spiroglycol and trimethylolpropane.

[0013] Preferably, the mass ratio of the dibasic acid, the first diol, the second diol and the modified monomer is 20-45:10-25:5-10:3-25.

[0014] Preferably, in the modified monomer, the mass ratio of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, spirodiol and trimethylolpropane is 1-1.3:1:1.

[0015] Preferably, during the esterification reaction, the reaction temperature is controlled to be 240-260° C. and the reaction pressure is controlled to be 0.2-0.3 MPa.

[0016] Preferably, during the polycondensation reaction, the reaction temperature is controlled to be 270-290°C.

[0017] Preferably, the polycondensation reaction is carried out under vacuum conditions with a vacuum degree of 10 to 500 Pa.

[0018] Preferably, the catalyst is selected from at least one of an antimony-based catalyst, a titanium-based catalyst and a germanium-based catalyst.

[0019] Preferably, the mass of the metal element in the catalyst is 10 to 100 ppm of the total mass of the raw materials.

[0020] Preferably, a stabilizer is added during the polycondensation reaction, and the stabilizer includes at least one of trimethyl phosphite, triethyl phosphite, triisooctyl phosphite, triisodecyl phosphite, trilauryl phosphite, triphenyl phosphite, tri-p-tolyl phosphite, di-p-phenyl tridecyl phosphite, tris(2,4-di-tert-butylbenzene) phosphite, di(2,4-di-p-isopropylphenyl)pentaerythritol diphosphite phosphoric acid, pentaerythritol tetraphenyl tridecyl phosphite, pentaerythritol diphosphite tridecyl, pentaerythritol diisodecyl diphosphite, tetraphenyl dipropylene glycol diphosphite, phosphoric acid, phosphorous acid, polyphosphoric acid and triethyl phosphonoacetate.

[0021] A modified copolyester material prepared by the method for preparing a modified copolyester material.

[0022] A use of the modified copolyester material in preparing a certificate card base.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The preparation method of the modified copolyester material provided by the present invention, by adding modified monomers for copolymerization, makes the modified copolyester material have excellent properties such as high transparency, high toughness, high strength, high modulus and solvent resistance.

[0025] (2) The modified copolyester material provided by the present invention has excellent properties of copolyester such as high transparency, high toughness, high strength, high modulus and solvent resistance. The ether bonds contained in it have low cohesive energy and can effectively reduce the risk of card delamination as a card base material. DETAILED DESCRIPTION

[0026] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be appreciated by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work, all belong to the scope of protection of the present invention. If specific conditions are not indicated in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0027] In a first aspect, a method for preparing a modified copolyester material provided by an embodiment of the present invention comprises the following steps:

[0028] The dibasic acid, the first diol, the second diol and the modified monomer are mixed and subjected to an esterification reaction, and after the esterification reaction is completed, a catalyst is added and a polycondensation reaction is carried out, and after the polycondensation reaction is completed, a modified copolyester material is obtained;

[0029] The dibasic acid includes terephthalic acid, the first diol includes ethylene glycol, the second diol includes 1,4-cyclohexanedimethanol or neopentyl glycol, and the modified monomer includes at least one of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, spiroglycol and trimethylolpropane.

[0030] In the present invention, the raw materials include two diol monomers, and by adding modified monomers for copolymerization, the modified copolyester material has excellent properties such as high transparency, high toughness, high strength, high modulus and solvent resistance. Specifically, the method provided by the present invention introduces alicyclic rings to absorb the energy generated by external force through conformational transformation, and the conformational transformation is conducive to the movement of the molecular chain, thereby improving the toughness of the material. The trihydroxymethylpropane molecular structure introduced by the method provided by the present invention contains three primary hydroxyl groups, and the steric hindrance effect of the ethyl group above can shield the ester group of the polyester, improve solvent resistance, and reduce solvent penetration during ink printing. The added spirodiol can increase the crosslinking density of the polyester, increase the hardness of the material, and realize laser etching; the ether bond cohesive energy it contains is low, and as a card-based material, it can effectively reduce the risk of card delamination.

[0031] In one embodiment, the mass ratio of the dibasic acid, the first diol, the second diol and the modified monomer is 20-45:10-25:5-10:3-25. The mass ratio may be any one of 20:10:5:3, 30:15:10:10, 40:20:8:20, 30:15:10:10, 45:25:10:25 or a range of any two of the ratios.

[0032] In one embodiment, the modified monomer is composed of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, spirodiol and trimethylolpropane. Further, in the modified monomer, the mass ratio of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, spirodiol and trimethylolpropane is 1 to 1.3:1:1, for example, any ratio of 1:1:1, 1.1:1:1, 1.2:1:1, 1.3:1:1 or any two ratios.

[0033] In one embodiment, during the esterification reaction, the reaction temperature is controlled to be 240-260°C, for example, any point value among 240°C, 245°C, 250°C, 255°C, and 260°C, or a range value consisting of any two points; the reaction pressure is 0.2-0.3MPa, for example, any point value among 0.2MPa, 0.25MPa, and 0.3MPa, or a range value consisting of any two points.

[0034] In one embodiment, after the esterification reaction, the pressure is released to normal pressure, a catalyst is added, and the temperature is gradually increased to control the temperature of the polycondensation reaction to be 270-290°C, for example, any point value among 270°C, 275°C, 280°C, 285°C, and 290°C, or a range value consisting of any two point values.

[0035] In one embodiment, low vacuum is simultaneously drawn and then gradually switched to high vacuum. During the polycondensation reaction, the vacuum degree is 10 to 500 Pa, for example, 10 Pa, 50 Pa, 100 Pa, 200 Pa, 250 Pa, 300 Pa, 350 Pa, 400 Pa, 450 Pa, and 500 Pa.

[0036] In one embodiment, the method provided by the present invention is applicable to a wide range of catalysts, and the catalyst is selected from at least one of antimony catalysts, titanium catalysts and germanium catalysts. Among them, antimony catalysts include but are not limited to antimony trioxide, antimony acetate and ethylene glycol antimony. Titanium catalysts In the polycondensation reaction of polyester, titanate catalysts can cause large condensation reaction rate constants for carboxyl and hydroxyl groups, so the terminal carboxyl groups generated by thermal degradation during the polycondensation reaction can still quickly undergo polycondensation reactions with other prepolymers. Titanium catalysts include but are not limited to tetrabutyl titanate and isopropyl titanate. Germanium catalysts include but are not limited to germanium dioxide and sodium germanate.

[0037] Furthermore, the mass of the metal element in the catalyst is 10 to 100 ppm of the total mass of the raw materials. The total mass of the raw materials refers to the mass sum of the dibasic acid, the first diol, the second diol and the modified monomer. The addition ratio includes but is not limited to any point value of 10ppm, 20ppm, 30ppm, 40ppm, 50ppm, 60ppm, 70ppm, 80ppm, 90ppm, 100ppm or a range value consisting of any two point values.

[0038] In one embodiment, a stabilizer is added during the polycondensation reaction, and the stabilizer is mainly used to improve the weather resistance and thermal stability of the polyester material, thereby extending its service life. It mainly prevents the polyester material from degrading and aging by absorbing or dispersing harmful substances such as ultraviolet rays, heat energy or oxides. The stabilizer includes but is not limited to trimethyl phosphite, triethyl phosphite, triisooctyl phosphite, triisodecyl phosphite, trilauryl phosphite, triphenyl phosphite, tri-p-tolyl phosphite, diphenyl tridecyl phosphite, tri(2,4-di-tert-butylbenzene) phosphite, di(2,4-di-p-isopropylphenyl) pentaerythritol diphosphite phosphoric acid, pentaerythritol tetraphosphite phenyl tridecyl ester, pentaerythritol diphosphite tridecyl ester, pentaerythritol diphosphite diisodecyl ester, tetraphenyl dipropylene glycol diphosphite, phosphoric acid, phosphoric acid, polyphosphoric acid and at least one of triethyl phosphonoacetate, and the stabilizer is added according to the needs of the material.

[0039] Furthermore, the amount of stabilizer added can be based on the conventional amount in the field.

[0040] In the second aspect, an embodiment of the present invention provides a modified copolyester material having the excellent properties of copolyester such as high transparency, high toughness, high strength, high modulus and solvent resistance. The ether bonds contained in the material have low cohesive energy and can be used as a card-based material to effectively reduce the risk of card delamination.

[0041] In the third aspect, an embodiment of the present invention provides a use of a modified copolyester material in the preparation of a card base for a certificate. The material is used as a card base material, which is convenient for molding, processing and printing. It can be used to produce certificates with high quality requirements, such as legal certificates, effectively reducing the risk of card delamination and having both strength and toughness.

[0042] Example 1

[0043] This embodiment provides another method for preparing a modified copolyester material, comprising the following steps:

[0044] 30 parts of phthalic acid, 15 parts of ethylene glycol, 8 parts of 1,4-cyclohexanedimethanol, 6 parts of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 6 parts of spiroglycol and 6 parts of trimethylolpropane were mixed, and esterification reaction was carried out at a temperature of 240°C and a pressure of 0.2MPa. When the water output reached the theoretical value, the esterification stage was ended, the pressure was released to normal pressure, and a catalyst was added. The amount of the catalyst added was 10ppm of the total mass of the raw materials. The temperature was gradually raised to 270°C, and low vacuum was simultaneously drawn, and then gradually switched to high vacuum. A condensation reaction was carried out under vacuum conditions. The temperature was controlled at 270°C and the vacuum degree was 10Pa. After the reaction was completed, the material was discharged, and polyester material slices were obtained through cooling and granulation.

[0045] Example 2

[0046] This embodiment provides another method for preparing a modified copolyester material, comprising the following steps:

[0047] 35 parts of phthalic acid, 17 parts of ethylene glycol, 6 parts of 1,4-cyclohexanedimethanol, 8 parts of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 8 parts of spiroglycol and 8 parts of trimethylolpropane were mixed, and esterification reaction was carried out at a temperature of 250°C and a pressure of 0.25MPa. When the water output reached the theoretical value, the esterification stage was ended, the pressure was released to normal pressure, and a catalyst was added. The amount of the catalyst added was 100ppm of the total mass of the raw materials. The temperature was gradually raised to 270°C, and low vacuum was simultaneously drawn, and then gradually switched to high vacuum. The polycondensation reaction was carried out under vacuum conditions. The temperature was controlled at 280°C and the vacuum degree was 500Pa. After the reaction was completed, the material was discharged, and polyester material slices were obtained through cooling and granulation.

[0048] Example 3

[0049] This embodiment provides another method for preparing a modified copolyester material, comprising the following steps:

[0050] 40 parts of phthalic acid, 16 parts of ethylene glycol, 7 parts of 1,4-cyclohexanedimethanol, 10 parts of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 10 parts of spiroglycol and 10 parts of trimethylolpropane were mixed, and esterification reaction was carried out at a temperature of 260°C and a pressure of 0.3MPa. When the water output reached the theoretical value, the esterification stage was ended, the pressure was released to normal pressure, and a catalyst was added. The amount of the catalyst added was 50ppm of the total mass of the raw materials. The temperature was gradually raised to 270°C, and low vacuum was simultaneously drawn, and then gradually switched to high vacuum. The polycondensation reaction was carried out under vacuum conditions. The temperature was controlled at 290°C and the vacuum degree was 100Pa. When the stirring current reached the rated value, the material was discharged, and polyester material slices were obtained after cooling and granulation.

[0051] Example 4

[0052] This embodiment provides another method for preparing a modified copolyester material, comprising the following steps:

[0053] 45 parts of phthalic acid, 25 parts of ethylene glycol, 10 parts of neopentyl glycol, 6.5 parts of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 5 parts of spiroglycol and 5 parts of trimethylolpropane are mixed, and esterification reaction is carried out at a temperature of 250°C and a pressure of 0.2MPa. When the water output reaches the theoretical value, the esterification stage is ended, the pressure is released to normal pressure, and a catalyst is added. The amount of the catalyst added is 60ppm of the total mass of the raw materials. The temperature is gradually raised to 270°C, and low vacuum is simultaneously drawn, and then gradually switched to high vacuum. A polycondensation reaction is carried out under vacuum conditions. The temperature is controlled at 275°C and the vacuum degree is 200Pa. When the stirring current reaches the rated value, the material is discharged, and polyester material slices are obtained after cooling and granulation.

[0054] Example 5

[0055] This embodiment provides another method for preparing a modified copolyester material, comprising the following steps:

[0056] 20 parts of phthalic acid, 10 parts of ethylene glycol, 5 parts of neopentyl glycol, 1 part of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 1 part of spiroglycol and 1 part of trimethylolpropane were mixed, and esterification reaction was carried out at a temperature of 255°C and a pressure of 0.2MPa. When the water output reached the theoretical value, the esterification stage was ended, the pressure was released to normal pressure, and a catalyst was added. The amount of the catalyst added was 30ppm of the total mass of the raw materials. The temperature was gradually raised to 270°C, and low vacuum was simultaneously drawn, and then gradually switched to high vacuum. The polycondensation reaction was carried out under vacuum conditions. The temperature was controlled at 285°C and the vacuum degree was 300Pa. After the reaction was completed, the material was discharged, and polyester material slices were obtained through cooling and granulation.

[0057] Comparative Example 1

[0058] Compared with Example 1, Comparative Example 1 has the same reaction conditions, but no modified monomer is added, and the mass fraction of the modified monomer is distributed to the three raw material monomers according to the mass ratio of phthalic acid, ethylene glycol and 1,4-cyclohexanedimethanol in Example 1 to ensure that the total mass of the raw materials in Comparative Example 1 is the same as that in Example 1.

[0059] Test Example 1 Polyester Material Performance Test

[0060] The performance tests were performed on the modified materials provided in Examples 1 to 5 and Comparative Example 1. The test results are shown in Table 1.

[0061] Among them, the mechanical properties (tensile strain at break, strength and tensile elastic modulus) were measured according to the national standard GB / T1040.3-2006 test method. The impact strength was measured according to the test method specified in the national standard GB / T1843-2008. The solvent resistance was tested according to the national standard GB / T11547-2008.

[0062] Table 1 Polyester material performance test results

[0063] project Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Tensile strain at break / % 246.67 347.15 332.06 311.17 330.8 321.7 Strength / MPa 55.26 62.24 61.36 69.49 65.8 64.2 Tensile elastic modulus / MPa 1978.16 2395.25 2378.15 2307.45 2357.46 2364.8 Impact strength / J / m 49.34 63.46 59.37 56.49 61.36 60.47 Solvent resistance Serious changes Slight changes Slight changes Slight changes Slight changes Slight changes

[0064] The preparation method of the modified copolyester material provided by the present invention is based on terephthalic acid, ethylene glycol, 1,4-cyclohexanedimethanol (or neopentyl glycol), and by adding modified monomers: 2,2,4,4-tetramethyl-1,3-cyclobutanediol, spirodiol, and trimethylolpropane, the strength, toughness, and solvent resistance of the copolyester polymerized by direct esterification are significantly improved. The modified copolyester material provided by the embodiment of the present invention has a tensile strain at break of >300%, a strength of >60MPa, a tensile elastic modulus of >2300MPa, and an impact strength of >55J / m, which is better than comparative example 1. According to the national standard GB / T11547-2008, the tolerance of the polyester material to ethyl acetate is tested. The appearance is only slightly changed by naked eye, while the change in comparative example 1 is serious. The material is used as a card base material, which is convenient for molding and printing. It can be used for the production of documents with high quality requirements, such as legal documents, which can effectively reduce the risk of card delamination and have both strength and toughness.

[0065] Although the present invention has been illustrated and described with specific embodiments, it should be appreciated that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Those skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some or all of the technical features thereof may be replaced by equivalents without departing from the spirit and scope of the present invention. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. Therefore, this means that all such replacements and modifications within the scope of the present invention are included in the appended claims.

Claims

1. A method for preparing a modified copolyester material, characterized in that: The following steps are involved: The dibasic acid, the first diol, the second diol and the modified monomer are mixed and subjected to an esterification reaction, after the esterification reaction is completed, a catalyst is added and a polycondensation reaction is carried out, and after the polycondensation reaction is completed, the modified copolyester material is obtained; The dibasic acid includes terephthalic acid, the first diol includes ethylene glycol, the second diol includes 1,4-cyclohexanedimethanol or neopentyl glycol, and the modified monomer includes at least one of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, spiroglycol and trimethylolpropane.

2. The method for preparing the modified copolyester material according to claim 1, characterized in that: The mass ratio of the dibasic acid, the first diol, the second diol and the modified monomer is 20-45:10-25:5-10:3-25.

3. The method for preparing the modified copolyester material according to claim 1 or 2, characterized in that: In the modified monomer, the mass ratio of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, spirodiol and trimethylolpropane is 1-1.3:1:

1.

4. The method for preparing the modified copolyester material according to claim 1 or 2, characterized in that: During the esterification reaction, the reaction temperature is controlled to be 240-260° C. and the reaction pressure is controlled to be 0.2-0.3 MPa.

5. The method for preparing the modified copolyester material according to claim 1 or 2, characterized in that: During the polycondensation reaction, the reaction temperature is controlled at 270-290°C.

6. The method for preparing the modified copolyester material according to claim 1 or 2, characterized in that: The polycondensation reaction is carried out under vacuum conditions with a vacuum degree of 10-500Pa.

7. The method for preparing the modified copolyester material according to claim 1 or 2, characterized in that: The catalyst is selected from at least one of an antimony-based catalyst, a titanium-based catalyst and a germanium-based catalyst; Preferably, the mass of the metal element in the catalyst is 10 to 100 ppm of the total mass of the raw materials.

8. The method for preparing the modified copolyester material according to claim 1 or 2, characterized in that: A stabilizer is added during the polycondensation reaction, and the stabilizer includes at least one of trimethyl phosphite, triethyl phosphite, triisooctyl phosphite, triisodecyl phosphite, trilauryl phosphite, triphenyl phosphite, tri-p-tolyl phosphite, diphenyl tridecyl phosphite, tris(2,4-di-tert-butylbenzene) phosphite, di(2,4-di-p-isopropylphenyl)pentaerythritol diphosphite phosphoric acid, pentaerythritol tetraphenyl tridecyl phosphite, pentaerythritol tridecyl diphosphite, pentaerythritol diisodecyl diphosphite, tetraphenyl dipropylene glycol diphosphite, phosphoric acid, phosphorous acid, polyphosphoric acid and triethyl phosphonoacetate.

9. The modified copolyester material prepared by the method for preparing a modified copolyester material according to any one of claims 1 to 8.

10. Use of the modified copolyester material according to claim 9 in preparing a certificate card base.