Branched antibacterial polyester as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of polyester industrial yarns, and relates to branched antibacterial polyester as well as a preparation method and application thereof. The preparation method comprises the following steps: firstly, controlling the carboxyl of first polyethylene glycol terephthalate to react with the epoxy group of glycidyl ether oxypropyl polyhedral oligomeric silsesquioxane to generate branched polyester, then controlling the hydroxyl of the branched polyester to react with the hydroxyl of 8-[(4-aminophenyl) azo]-7-hydroxyl-N, N, N-trimethyl-2-naphthalene quaternary ammonium hydrochloride to generate branched polyester, and finally controlling the hydroxyl of the branched polyester to react with the hydroxyl of 8-[(4-aminophenyl) azo]-7-hydroxyl-N, N, N-trimethyl-2-naphthalene quaternary ammonium hydrochloride to generate branched polyester. The branched antibacterial polyester is obtained. According to the application, the branched antibacterial polyester and second polyethylene glycol terephthalate are subjected to melt blending spinning, and the antibacterial polyester industrial yarn is prepared. The branched antibacterial polyester is easier to enrich on the fiber surface layer of the polyester industrial yarn, the antibacterial performance of the polyester industrial yarn is improved, meanwhile, the polyester industrial yarn can keep good mechanical performance, and the branched antibacterial polyester is suitable for large-scale industrial application.

Description

Technical Field

[0001] The invention belongs to the technical field of polyester industrial yarns, and specifically relates to a branched antibacterial polyester and a preparation method and application thereof. Background Art

[0002] Polyester industrial yarn is widely used in many industrial fields due to its excellent high strength, high modulus, low shrinkage and dimensional stability, such as ideal raw materials for car seat belts, light box advertising cloth, geotextile, lifting belt, etc. As the functional homogeneity of polyester industrial yarn becomes serious, the development of high-performance functional products is an inevitable trend for its future development.

[0003] According to the application of polyester industrial yarn in the sub-sectors, such as car seat belts, curtains, light box advertising cloth, etc., bacteria are easily bred during use, which not only affects human health, but also affects its safety and durability. Therefore, the development of polyester industrial yarn with antibacterial function has important practical value.

[0004] At present, melt spinning based on blending or adding functional masterbatch is a common method for preparing antibacterial polyester industrial yarn.

[0005] For example, patent application CN104018329A uses basic PET chips to add antibacterial materials to form antibacterial masterbatch, which is then mixed with high-viscosity polyester chips to form antibacterial chips, which are further melted and spun to prepare antibacterial polyester industrial yarns; however, the antibacterial materials added in this way are often homogeneously dispersed inside the fibers, and in fact, the antibacterial agent on the surface of the fibers often plays a major antibacterial role. Therefore, in order to improve the antibacterial properties of the fibers, a higher content of antibacterial agent needs to be added, which will cause a serious loss of mechanical properties of the fibers to a certain extent.

[0006] For example, patent application CN117646290A uses quaternary ammonium glycol, terephthalic acid, TEOS, etc. to synthesize low molecular weight flame retardant and antibacterial hydrophobic copolyester, and melt-blends and spins it with high molecular weight polyester to prepare flame retardant and antibacterial polyester industrial yarn, but still fails to achieve gradient dispersion of functional materials in the radial direction of the fiber, affecting the mechanical properties of the fiber.

[0007] There are also a few studies in the prior art that attempt to diffuse and enrich functional powders on the fiber surface. For example, patent application CN110257947A improves the utilization efficiency of antimicrobial agents by designing high shear induction of spinneret holes to enrich antimicrobial agents on the fiber surface. At the same time, the temperature of the hot roller is reduced to slow down the crystallization rate and avoid the problem of difficulty in drawing due to crystallization. However, these antimicrobial agents are functional powders such as silver ions, copper ions, and zinc ions, and the interaction between them and the PET matrix is ​​weak. Under the action of shear flow field and tensile flow field, the main chain of the polymer drives the functional powder to diffuse and enrich to a limited extent on the fiber surface. The content of antimicrobial powder in the surface layer of the antimicrobial polyester industrial yarn is 5-10wt% higher than that in the center. The enrichment of antimicrobial agents on the fiber surface and the mechanical properties of the fiber (>6.5cN / dtex) need to be further improved.

[0008] Therefore, developing a polyester industrial yarn with excellent mechanical properties and easy accumulation of antimicrobial agents on the fiber surface is a technical problem that needs to be solved urgently. Summary of the invention

[0009] The purpose of the present invention is to solve the above problems existing in the prior art and to provide a branched antibacterial polyester and a preparation method and application thereof.

[0010] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0011] A method for preparing a branched antibacterial polyester comprises the following steps: firstly controlling the carboxyl group of a first polyethylene terephthalate to react with the epoxy group of a glycidyloxypropyl cage-shaped polysilsesquioxane to generate a branched polyester; and then controlling the hydroxyl group of the branched polyester to react with the hydroxyl group of 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride to obtain the branched antibacterial polyester.

[0012] As the preferred technical solution:

[0013] The preparation method of the branched antibacterial polyester as described above specifically comprises the following steps: mixing the first polyethylene terephthalate with the glycidyl ether oxypropyl caged polysilsesquioxane, reacting the mixture at 250-255°C and -0.05--0.09 MPa for 3-5 min to obtain the branched polyester; and then mixing the branched polyester with 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium salt, reacting the mixture at 260-270°C and -0.05--0.09 MPa for 3-5 min to obtain the branched antibacterial polyester.

[0014] In the method for preparing a branched antibacterial polyester as described above, the molar ratio of the first polyethylene terephthalate to the glycidyl ether oxypropyl caged polysilsesquioxane is 8-8.2:1, and the molar ratio of the branched polyester to 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride is 1:8-8.2.

[0015] In the method for preparing a branched antibacterial polyester as described above, the number average molecular weight of the first polyethylene terephthalate is 1000-2000 g / mol.

[0016] The present invention also provides a branched antibacterial polyester, which is prepared by the preparation method of a branched antibacterial polyester as described in any one of the above items.

[0017] The present invention also provides an application of the branched antibacterial polyester as described above, wherein the branched antibacterial polyester is melt-blended and spun with a second polyethylene terephthalate to obtain an antibacterial polyester industrial yarn, wherein the zero shear viscosity of the branched antibacterial polyester is 300-500 Pa·s lower than that of the second polyethylene terephthalate at the extrusion temperature, and the aspect ratio of the spinneret hole is 1.2-1.5:1.

[0018] The zero shear viscosity of the branched antibacterial polyester in the present invention is 300-500 Pa·s lower than that of the second polyethylene terephthalate at the extrusion temperature. This is because the branched antibacterial polyester contains glycidyl ether oxypropyl cage-like polysilsesquioxane, and the molecular structure surface energy of the glycidyl ether oxypropyl cage-like polysilsesquioxane is low, which can play an internal lubricating role and reduce the melt viscosity of the branched antibacterial polyester; under the high shear effect in the spinneret hole, the branched antibacterial polyester with relatively lower viscosity tends to flow toward the hole wall, and the branched antibacterial polyester is easy to flow to the hole wall when it exits the spinneret hole. When the spinneret holes are formed, due to the small aspect ratio of the spinneret holes, the time for the melt to flow through the spinneret holes is short, and the molecular chains have no time to relax. Therefore, both the branched antibacterial polyester and the second polyethylene terephthalate are prone to outlet expansion. Among them, since the relaxation time required for the molecular chain of the branched antibacterial polyester is significantly longer than the relaxation time required for the second polyethylene terephthalate, the outlet expansion effect of the branched antibacterial polyester is more significant than that of the conventional polyester, so that the branched antibacterial polyester is enriched in the surface layer of the antibacterial polyester industrial yarn.

[0019] As the preferred technical solution:

[0020] In the application described above, the mass ratio of the branched antibacterial polyester to the second polyethylene terephthalate is 0.5:99.5 to 2:98.

[0021] In the application described above, the number average molecular weight of the second polyethylene terephthalate is 25000-38000 g / mol.

[0022] For the application described above, the process parameters of melt blending spinning include: extrusion temperature 300~320℃, post-heater temperature 300~320℃, cooling blowing speed 0.4~0.6m / s, cooling blowing temperature 20~28℃, first roller speed 600~1000m / min, hot roller stretching multiple 5~7 times.

[0023] As described above, the content of branched antibacterial polyester at the surface of the antibacterial polyester industrial yarn is 20~25wt% higher than that of branched antibacterial polyester at the center; the monofilament fineness of the antibacterial polyester industrial yarn is 3~8dtex, the breaking strength is 7.6~8.3cN / dtex, the breaking elongation is 10~20%, and the antibacterial rates against Staphylococcus aureus, Escherichia coli and Candida albicans are all above 99.5%. After washing 50 times, the antibacterial rates against Staphylococcus aureus, Escherichia coli and Candida albicans are still greater than 98%. According to the standard GB / T 16422.3-2022, the breaking strength retention rate is 80~88% after irradiation for 500h.

[0024] Beneficial effects:

[0025] (1) The branched antibacterial polyester of the present invention is more easily enriched on the fiber surface of the polyester industrial yarn, thereby improving the antibacterial properties of the polyester industrial yarn.

[0026] (2) The branched antibacterial polyester of the present invention contains a first polyethylene terephthalate, which serves as a branch chain in the branched antibacterial polyester and has the same chemical structure as the main polyester of the second polyethylene terephthalate industrial yarn, and has good compatibility, which is beneficial for the polyester industrial yarn to maintain good mechanical properties.

[0027] (3) The branched antibacterial polyester of the present invention contains 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride. As an azo compound, 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride has strong ultraviolet light absorption properties, thereby improving the anti-ultraviolet effect of polyester industrial yarn.

[0028] (4) The glycidyl ether oxypropyl cage-like polysilsesquioxane used in the preparation method of the present invention can improve the fluidity of the melt, which is not only beneficial for processing, but also reduces the spinning processing temperature and prevents thermal degradation of the melt. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0030] The following are the test methods for the relevant performance indicators in each embodiment and comparative example:

[0031] (1) Monofilament fineness of antibacterial polyester industrial yarn: tested in accordance with standard GB / T 14343-2008.

[0032] (2) Breaking strength: Tested in accordance with standard GB / T 16604-2017.

[0033] (3) Elongation at break: Tested in accordance with standard GB / T 16604-2017.

[0034] (4) Antibacterial rate against Staphylococcus aureus, Escherichia coli and Candida albicans: tested in accordance with standard GB / T20944.3-2008.

[0035] (5) Antibacterial rate against Staphylococcus aureus, Escherichia coli and Candida albicans after washing 50 times: tested in accordance with standard GB / T 20944.3-2008.

[0036] (6) Retention rate of breaking strength after irradiation for 500 h: tested in accordance with standard GB / T 16422.3-2022.

[0037] (7) The difference between the content of branched antibacterial polyester at the surface and the content of branched antibacterial polyester at the center of antibacterial polyester industrial yarn: Use a Hastelloy slicer to slice the dried pretreated fiber sample, carefully place the cut fiber slices on the sample stage of the microscopic infrared device, adjust the test position of the sample, obtain the spectrum of the fiber surface and the center, determine the content of branched antibacterial polyester at the surface and the content of branched antibacterial polyester at the center based on the absorption peak intensity of specific functional groups, and calculate the difference between the two.

[0038] In each of the embodiments and comparative examples of the present invention, the structures of the first polyethylene terephthalate and the second polyethylene terephthalate are as shown in formula (I).

[0039]

[0040] (I)

[0041] In various embodiments of the present invention, the structure of the glycidyloxypropyl cage-like polysilsesquioxane is shown in formula (II).

[0042]

[0043] (II)

[0044] In each of the embodiments and comparative examples of the present invention, the structure of 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride is shown in formula (III).

[0045]

[0046] (III)

[0047] Example 1

[0048] A method for preparing antibacterial polyester industrial yarn, the specific steps are as follows:

[0049] (1) Preparation of raw materials;

[0050] The first polyethylene terephthalate: number average molecular weight is 1000 g / mol;

[0051] Glycidyloxypropyl caged polysilsesquioxane;

[0052] 8-[(4-Aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride;

[0053] The second polyethylene terephthalate: number average molecular weight is 25000 g / mol;

[0054] (2) Preparation of branched antibacterial polyester;

[0055] The first polyethylene terephthalate and the glycidyl ether oxypropyl caged polysilsesquioxane are mixed, wherein the molar ratio of the first polyethylene terephthalate to the glycidyl ether oxypropyl caged polysilsesquioxane is 8:1, and the mixture is reacted at 250° C. and −0.05 MPa for 3 minutes to obtain a branched polyester;

[0056] The branched polyester is then mixed with 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride, wherein the molar ratio of the branched polyester to the 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride is 1:8, and reacted at 260° C. and −0.05 MPa for 3 min to obtain a branched antibacterial polyester;

[0057] (3) Melt blending spinning;

[0058] The branched antibacterial polyester and the second polyethylene terephthalate were melt-blended and spun at a mass ratio of 0.5:99.5 to obtain antibacterial polyester industrial yarn, wherein the zero shear viscosity of the branched antibacterial polyester was 300 Pa·s lower than that of the second polyethylene terephthalate at the extrusion temperature, and the aspect ratio of the spinneret hole was 1.2:1;

[0059] The process parameters of melt blending spinning are: extrusion temperature 300°C, post-heater temperature 300°C, cooling blowing speed 0.4m / s, cooling blowing temperature 20°C, one roller speed 600m / min, hot roller drafting multiple 5 times.

[0060] The antibacterial polyester industrial yarn finally prepared has branched antibacterial polyester enriched in the surface layer of the antibacterial polyester industrial yarn, and the content of branched antibacterial polyester in the surface layer is 20wt% higher than that in the center. The monofilament fineness of the antibacterial polyester industrial yarn is 8dtex, the breaking strength is 7.6cN / dtex, the breaking elongation is 20%, the antibacterial rate against Staphylococcus aureus is 99.6%, the antibacterial rate against Escherichia coli is 99.7%, and the antibacterial rate against Candida albicans is 99.6%. The antibacterial rates of Staphylococcus aureus, Escherichia coli and Candida albicans were all above 99.5%. After washing with water for 50 times, the antibacterial rates of Staphylococcus aureus were 98.1%, the antibacterial rates of Escherichia coli were 98.05% and the antibacterial rates of Candida albicans were 98.27% respectively. After washing with water for 50 times, the antibacterial rates of Staphylococcus aureus, Escherichia coli and Candida albicans were still greater than 98%. According to GB / T 16422.3-2022, the breaking strength retention rate was 80% after irradiation for 500h.

[0061] Comparative Example 1

[0062] A method for preparing polyester industrial yarn is basically the same as that of Example 1, except that glycidyloxypropyl cyclotetrasiloxane is used instead of glycidyloxypropyl cage-like polysilsesquioxane, and the structure of glycidyloxypropyl cyclotetrasiloxane is shown in formula (IV).

[0063]

[0064] (IV)

[0065] The final polyester industrial yarn has a single yarn fineness of 8 dtex, a breaking strength of 7.1 cN / dtex, an elongation at break of 21%, an antibacterial rate against Staphylococcus aureus of 96%, an antibacterial rate against Escherichia coli of 96.4%, and an antibacterial rate against Candida albicans of 96.89%. After washing with water 50 times, the antibacterial rate against Staphylococcus aureus is 94%, the antibacterial rate against Escherichia coli after washing with water 50 times is 94.38%, and the antibacterial rate against Candida albicans after washing with water 50 times is 94.44%. According to GB / T 16422.3-2022, the breaking strength retention rate after irradiation for 500 hours is 73%.

[0066] Comparing Comparative Example 1 with Example 1, the antibacterial property of Comparative Example 1 is significantly reduced, and the strength retention rate after light aging is also significantly reduced. This is because the number of branched chains of glycidyloxypropyl cyclotetrasiloxane is small, the number of introduced antibacterial and anti-ultraviolet groups is small, the outlet puffing effect when exiting the spinneret hole will be weakened, the degree of diffusion to the surface of the polyester industrial yarn fiber is relatively low, and it is not easy to be enriched in the surface layer of the polyester industrial yarn, thereby reducing the antibacterial and mechanical properties.

[0067] Comparative Example 2

[0068] A method for preparing polyester industrial yarn is basically the same as that of Example 1, except that the aspect ratio of the spinneret hole is 1.6:1.

[0069] The final polyester industrial yarn has a breaking strength of 7.2 cN / dtex, an elongation at break of 19.7%, an antibacterial rate against Staphylococcus aureus of 98.5%, an antibacterial rate against Escherichia coli of 98.8%, and an antibacterial rate against Candida albicans of 98.4%. After washing with water for 50 times, the antibacterial rate against Staphylococcus aureus is 97.6%, the antibacterial rate against Escherichia coli after washing with water for 50 times is 97.3%, and the antibacterial rate against Candida albicans after washing with water for 50 times is 97.1%. According to GB / T 16422.3-2022, the breaking strength retention rate is 78% after irradiation for 500 hours.

[0070] By comparing Example 1 with Comparative Example 2, it can be seen that the strength of the fiber decreases and the antibacterial performance is also reduced. This is because the aspect ratio of the spinneret in Comparative Example 2 is larger, and the melt flows through the spinneret for a long time, which is conducive to the relaxation of the molecular chain. After leaving the spinneret, the outlet expansion effect of the melt is weakened, which is not conducive to the enrichment of the branched antibacterial polyester to the fiber surface, thereby reducing the antibacterial performance of the fiber. At the same time, too much branched antibacterial polyester in the fiber core layer will affect the orientation of the core layer polyethylene terephthalate to a certain extent, thereby reducing the mechanical properties of the fiber.

[0071] Comparative Example 3

[0072] A method for preparing polyester industrial yarn is basically the same as that of Example 1, except that the number average molecular weight of the second polyethylene terephthalate is 20,000 g / mol, resulting in a zero shear viscosity of the branched antibacterial polyester being 200 Pa·s lower than that of the second polyethylene terephthalate at the extrusion temperature.

[0073] The final polyester industrial yarn has a breaking strength of 6.5 cN / dtex, an elongation at break of 21%, an antibacterial rate against Staphylococcus aureus of 97%, an antibacterial rate against Escherichia coli of 96.4%, and an antibacterial rate against Candida albicans of 96.2%. After washing with water for 50 times, the antibacterial rate against Staphylococcus aureus is 96.3%, the antibacterial rate against Escherichia coli after washing with water for 50 times is 95.4%, and the antibacterial rate against Candida albicans after washing with water for 50 times is 95.1%. According to GB / T 16422.3-2022, the breaking strength retention rate is 72% after irradiation for 500 hours.

[0074] By comparing Example 1 with Comparative Example 3, it can be seen that the strength and antibacterial properties of the fiber are both reduced. This is because in Comparative Example 3, the zero shear viscosity difference between the branched antibacterial polyester and the second polyethylene terephthalate at the extrusion temperature is small, which is not conducive to the diffusion of the branched antibacterial polyester to the fiber surface. At the same time, the molecular weight of polyethylene terephthalate is low, resulting in a decrease in the strength of the fiber.

[0075] Example 2

[0076] A method for preparing antibacterial polyester industrial yarn, the specific steps are as follows:

[0077] (1) Preparation of raw materials;

[0078] The first polyethylene terephthalate: number average molecular weight is 1300 g / mol;

[0079] Glycidyloxypropyl caged polysilsesquioxane;

[0080] 8-[(4-Aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride;

[0081] The second polyethylene terephthalate: number average molecular weight is 28000 g / mol;

[0082] (2) Preparation of branched antibacterial polyester;

[0083] The first polyethylene terephthalate and the glycidyl ether oxypropyl caged polysilsesquioxane are mixed, wherein the molar ratio of the first polyethylene terephthalate to the glycidyl ether oxypropyl caged polysilsesquioxane is 8.05:1, and the mixture is reacted at 251° C. and −0.06 MPa for 3.5 min to obtain a branched polyester;

[0084] The branched polyester is then mixed with 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride, wherein the molar ratio of the branched polyester to the 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride is 1:8.05, and reacted at 263° C. and −0.06 MPa for 3.5 min to obtain a branched antibacterial polyester;

[0085] (3) Melt blending spinning;

[0086] The branched antibacterial polyester and the second polyethylene terephthalate were melt-blended and spun at a mass ratio of 1:99 to obtain antibacterial polyester industrial yarn, wherein the zero shear viscosity of the branched antibacterial polyester was 350 Pa·s lower than that of the second polyethylene terephthalate at the extrusion temperature, and the aspect ratio of the spinneret hole was 1.3:1;

[0087] The process parameters of melt blending spinning are: extrusion temperature 305°C, post-heater temperature 305°C, cooling blowing speed 0.45m / s, cooling blowing temperature 22°C, one roller speed 800m / min, hot roller drafting multiple 5.5 times.

[0088] The antibacterial polyester industrial yarn finally prepared has branched antibacterial polyester enriched in the surface layer of the antibacterial polyester industrial yarn, and the content of branched antibacterial polyester in the surface layer is 21.5wt% higher than that in the center. The single yarn fineness of the antibacterial polyester industrial yarn is 5dtex, the breaking strength is 7.8cN / dtex, the breaking elongation is 18%, the antibacterial rate against Staphylococcus aureus is 99.7%, the antibacterial rate against Escherichia coli is 99.75%, and the antibacterial rate against Candida albicans is 99. The antibacterial rate is 99.72%, and the antibacterial rates against Staphylococcus aureus, Escherichia coli and Candida albicans are all above 99.5%. After washing with water 50 times, the antibacterial rate against Staphylococcus aureus is 98.4%, the antibacterial rate against Escherichia coli after washing with water 50 times is 98.23%, and the antibacterial rate against Candida albicans after washing with water 50 times is 98.78%. After washing with water 50 times, the antibacterial rates against Staphylococcus aureus, Escherichia coli and Candida albicans are still greater than 98%. According to GB / T 16422.3-2022, the breaking strength retention rate after irradiation for 500h is 82%.

[0089] Example 3

[0090] A method for preparing antibacterial polyester industrial yarn, the specific steps are as follows:

[0091] (1) Preparation of raw materials;

[0092] The first polyethylene terephthalate: number average molecular weight is 1500 g / mol;

[0093] Glycidyloxypropyl caged polysilsesquioxane;

[0094] 8-[(4-Aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride;

[0095] The second polyethylene terephthalate: number average molecular weight is 30000 g / mol;

[0096] (2) Preparation of branched antibacterial polyester;

[0097] The first polyethylene terephthalate and the glycidyl ether oxypropyl caged polysilsesquioxane are mixed, wherein the molar ratio of the first polyethylene terephthalate to the glycidyl ether oxypropyl caged polysilsesquioxane is 8.1:1, and the mixture is reacted at 253° C. and −0.07 MPa for 4 minutes to obtain a branched polyester;

[0098] The branched polyester is then mixed with 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride, wherein the molar ratio of the branched polyester to the 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride is 1:8.1; the mixture is reacted at 265° C. and −0.07 MPa for 4 minutes to obtain the branched antibacterial polyester;

[0099] (3) Melt blending spinning;

[0100] The branched antibacterial polyester and the second polyethylene terephthalate were melt-blended and spun at a mass ratio of 1.3:98.7 to obtain antibacterial polyester industrial yarn, wherein the zero shear viscosity of the branched antibacterial polyester was 400 Pa·s lower than that of the second polyethylene terephthalate at the extrusion temperature, and the aspect ratio of the spinneret hole was 1.4:1;

[0101] The process parameters of melt blending spinning are: extrusion temperature 310°C, post-heater temperature 310°C, cooling blowing speed 0.5m / s, cooling blowing temperature 24°C, one roller speed 900m / min, hot roller drafting multiple 6 times.

[0102] The antibacterial polyester industrial yarn finally prepared has branched antibacterial polyester enriched in the surface layer of the antibacterial polyester industrial yarn, and the content of branched antibacterial polyester in the surface layer is 22.8wt% higher than that in the center. The single yarn fineness of the antibacterial polyester industrial yarn is 4 dtex, the breaking strength is 8.0 cN / dtex, the breaking elongation is 14%, the antibacterial rate against Staphylococcus aureus is 99.75%, the antibacterial rate against Escherichia coli is 99.81%, and the antibacterial rate against Candida albicans is 99.81%. The antibacterial rate is 99.78%, and the antibacterial rates against Staphylococcus aureus, Escherichia coli and Candida albicans are all above 99.5%. After washing with water 50 times, the antibacterial rate against Staphylococcus aureus is 98.8%, the antibacterial rate against Escherichia coli after washing with water 50 times is 98.74%, and the antibacterial rate against Candida albicans after washing with water 50 times is 98.86%. After washing with water 50 times, the antibacterial rates against Staphylococcus aureus, Escherichia coli and Candida albicans are still greater than 98%. According to GB / T 16422.3-2022, the breaking strength retention rate after irradiation for 500h is 85%.

[0103] Example 4

[0104] A method for preparing antibacterial polyester industrial yarn, the specific steps are as follows:

[0105] (1) Preparation of raw materials;

[0106] The first polyethylene terephthalate: number average molecular weight is 1800 g / mol;

[0107] Glycidyloxypropyl caged polysilsesquioxane;

[0108] 8-[(4-Aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride;

[0109] The second polyethylene terephthalate: number average molecular weight is 35000 g / mol;

[0110] (2) Preparation of branched antibacterial polyester;

[0111] The first polyethylene terephthalate and the glycidyl ether oxypropyl caged polysilsesquioxane are mixed, wherein the molar ratio of the first polyethylene terephthalate to the glycidyl ether oxypropyl caged polysilsesquioxane is 8.15:1, and the mixture is reacted at 254° C. and −0.08 MPa for 4.5 min to obtain a branched polyester;

[0112] The branched polyester is then mixed with 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride, wherein the molar ratio of the branched polyester to the 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride is 1:8.15, and reacted at 267° C. and −0.08 MPa for 4.5 min to obtain a branched antibacterial polyester;

[0113] (3) Melt blending spinning;

[0114] The branched antibacterial polyester and the second polyethylene terephthalate were melt-blended and spun at a mass ratio of 1.7:98.3 to obtain antibacterial polyester industrial yarn, wherein the zero shear viscosity of the branched antibacterial polyester was 450 Pa·s lower than that of the second polyethylene terephthalate at the extrusion temperature, and the aspect ratio of the spinneret hole was 1.45:1;

[0115] The process parameters of melt blending spinning are: extrusion temperature 315°C, post-heater temperature 315°C, cooling blowing speed 0.55m / s, cooling blowing temperature 26°C, one roller speed 950m / min, hot roller drafting multiple 6.5 times.

[0116] The antibacterial polyester industrial yarn finally prepared has branched antibacterial polyester enriched in the surface layer of the antibacterial polyester industrial yarn, and the content of branched antibacterial polyester in the surface layer is 23.6wt% higher than that in the center. The single yarn fineness of the antibacterial polyester industrial yarn is 3.5dtex, the breaking strength is 8.15cN / dtex, the breaking elongation is 12%, the antibacterial rate against Staphylococcus aureus is 99.8%, the antibacterial rate against Escherichia coli is 99.85%, and the antibacterial rate against Candida albicans is 99.8%. The antibacterial rate is 99.80%, and the antibacterial rates against Staphylococcus aureus, Escherichia coli and Candida albicans are all above 99.5%. After washing with water 50 times, the antibacterial rate against Staphylococcus aureus is 99%, the antibacterial rate against Escherichia coli after washing with water 50 times is 99.01%, and the antibacterial rate against Candida albicans after washing with water 50 times is 98.98%. After washing with water 50 times, the antibacterial rates against Staphylococcus aureus, Escherichia coli and Candida albicans are still greater than 98%. According to GB / T 16422.3-2022, the breaking strength retention rate after irradiation for 500h is 86%.

[0117] Example 5

[0118] A method for preparing antibacterial polyester industrial yarn, the specific steps are as follows:

[0119] (1) Preparation of raw materials;

[0120] The first polyethylene terephthalate: number average molecular weight is 2000 g / mol;

[0121] Glycidyloxypropyl caged polysilsesquioxane;

[0122] 8-[(4-Aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride;

[0123] The second polyethylene terephthalate: number average molecular weight is 38000 g / mol;

[0124] (2) Preparation of branched antibacterial polyester;

[0125] The first polyethylene terephthalate and the glycidyl ether oxypropyl caged polysilsesquioxane are mixed, wherein the molar ratio of the first polyethylene terephthalate to the glycidyl ether oxypropyl caged polysilsesquioxane is 8.2:1, and the mixture is reacted at 255° C. and −0.09 MPa for 5 minutes to obtain a branched polyester;

[0126] The branched polyester is then mixed with 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride, wherein the molar ratio of the branched polyester to the 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride is 1:8.2, and reacted at 270° C. and −0.09 MPa for 5 min to obtain a branched antibacterial polyester;

[0127] (3) Melt blending spinning;

[0128] The branched antibacterial polyester and the second polyethylene terephthalate are melt-blended and spun at a mass ratio of 2:98 to obtain antibacterial polyester industrial yarn, wherein the zero shear viscosity of the branched antibacterial polyester is 500 Pa·s lower than that of the second polyethylene terephthalate at the extrusion temperature, and the aspect ratio of the spinneret hole is 1.5:1;

[0129] The process parameters of melt blending spinning are: extrusion temperature 320°C, post-heater temperature 320°C, cooling blowing speed 0.6m / s, cooling blowing temperature 28°C, one roller speed 1000m / min, hot roller drafting multiple 7 times.

[0130] The antibacterial polyester industrial yarn finally prepared has branched antibacterial polyester enriched in the surface layer of the antibacterial polyester industrial yarn, and the content of branched antibacterial polyester in the surface layer is 25wt% higher than that in the center. The single yarn fineness of the antibacterial polyester industrial yarn is 3dtex, the breaking strength is 8.3cN / dtex, the breaking elongation is 10%, the antibacterial rate against Staphylococcus aureus is 99.9%, the antibacterial rate against Escherichia coli is 99.88%, and the antibacterial rate against Candida albicans is 99.9%. The antibacterial rate of the irradiated paper is 99.92%, and the antibacterial rates against Staphylococcus aureus, Escherichia coli and Candida albicans are all above 99.5%. After washing with water for 50 times, the antibacterial rate against Staphylococcus aureus is 99.3%, the antibacterial rate against Escherichia coli is 99.12% after washing with water for 50 times, and the antibacterial rate against Candida albicans is 99.19% after washing with water for 50 times. After washing with water for 50 times, the antibacterial rates against Staphylococcus aureus, Escherichia coli and Candida albicans are still greater than 98%. According to GB / T 16422.3-2022, the breaking strength retention rate after irradiation for 500h is 88%.

Claims

1. A method for preparing a branched antibacterial polyester, characterized in that: First, the carboxyl group of the first polyethylene terephthalate is controlled to react with the epoxy group of the glycidyl ether oxypropyl cage-like polysilsesquioxane to generate a branched polyester, and then the hydroxyl group of the branched polyester is controlled to react with the hydroxyl group of 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride to obtain the branched antibacterial polyester.

2. The method for preparing a branched antibacterial polyester according to claim 1, characterized in that: The specific process is: after mixing the first polyethylene terephthalate with glycidyloxypropyl caged polysilsesquioxane, reacting at 250~255°C and -0.05~-0.09MPa for 3~5min to obtain a branched polyester, and then mixing the branched polyester with 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium salt, reacting at 260~270°C and -0.05~-0.09MPa for 3~5min to obtain a branched antibacterial polyester.

3. The method for preparing a branched antibacterial polyester according to claim 2, characterized in that: The molar ratio of the first polyethylene terephthalate to the glycidyl ether oxypropyl caged polysilsesquioxane is 8-8.2:1, and the molar ratio of the branched polyester to 8-[(4-aminophenyl)azo]-7-hydroxy-N,N,N-trimethyl-2-naphthyl quaternary ammonium hydrochloride is 1:8-8.

2.

4. The method for preparing a branched antibacterial polyester according to claim 2, characterized in that: The first polyethylene terephthalate has a number average molecular weight of 1000-2000 g / mol.

5. A branched antibacterial polyester, characterized in that: The antibacterial polyester is prepared by the method for preparing the branched antibacterial polyester as described in any one of claims 1 to 4.

6. The use of a branched antibacterial polyester as claimed in claim 5, characterized in that: The branched antibacterial polyester and the second polyethylene terephthalate are melt-blended and spun to obtain antibacterial polyester industrial yarn. The zero shear viscosity of the branched antibacterial polyester is 300-500 Pa·s lower than that of the second polyethylene terephthalate at the extrusion temperature, and the aspect ratio of the spinneret hole is 1.2-1.5:

1.

7. The use according to claim 6, characterized in that: The mass ratio of the branched antibacterial polyester to the second polyethylene terephthalate is 0.5:99.5-2:

98.

8. The use according to claim 6, characterized in that: The second polyethylene terephthalate has a number average molecular weight of 25000-38000 g / mol.

9. The use according to claim 6, characterized in that: The process parameters of melt blending spinning include: extrusion temperature 300~320℃, post-heater temperature 300~320℃, cooling blowing speed 0.4~0.6m / s, cooling blowing temperature 20~28℃, first roller speed 600~1000m / min, hot roller drawing multiple 5~7 times.

10. The use according to claim 6, characterized in that: The content of branched antibacterial polyester at the surface of the antibacterial polyester industrial yarn is 20~25wt% higher than that of branched antibacterial polyester at the center; the monofilament fineness of the antibacterial polyester industrial yarn is 3~8dtex, the breaking strength is 7.6~8.3cN / dtex, the breaking elongation is 10~20%, and the antibacterial rates against Staphylococcus aureus, Escherichia coli and Candida albicans are all above 99.5%. After washing 50 times, the antibacterial rates against Staphylococcus aureus, Escherichia coli and Candida albicans are still greater than 98%. According to the standard GB / T 16422.3-2022, the breaking strength retention rate is 80~88% after irradiation for 500 hours.

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