Biodegradable PET-based spun-bonded non-woven fabric and preparation method thereof

Abstract

The invention relates to the field of non-woven fabrics, and provides a biodegradable PET (polyethylene terephthalate)-based spun-bonded non-woven fabric and a preparation method thereof aiming at the problem of poor degradation capacity or mechanical property of PET textiles, and the preparation method comprises the following steps: melting and extruding PET-based degradable polyester, spinning, drafting, separating and lapping, and hot-rolling and solidifying; monomers of the PET-based degradable polyester comprise terephthalic acid, ethylene glycol and a third monomer in a molar ratio of 1: (0.8-1.5): (0.08-0.4), the third monomer is binary acid or hydroxy acid with the carbon chain length of 2-6, and the melt index of the polyester is 60-110 g / 10 min; the airflow speed for drafting is 3000 to 5000 m / min; the lapping speed is 5-40 m / min; and the hot rolling temperature is 70-85 DEG C. According to the invention, the biodegradable PET-based spun-bonded non-woven fabric with excellent mechanical properties is obtained by adjusting polyester monomer components and spun-bonded spinning processing technological parameters.

Description

Technical Field

[0001] The invention relates to the field of nonwoven fabrics, and in particular to a biodegradable PET-based spunbonded nonwoven fabric and a preparation method thereof. Background Art

[0002] Spunbond nonwoven fabrics made of PET (polyethylene terephthalate) have excellent physical properties, including: high temperature resistance, which can maintain good dimensional stability under conditions requiring temperature resistance; high tensile strength, tear resistance, and aging resistance; low hygroscopicity, and are water-repellent nonwoven fabrics. The heavier and thicker the fabric, the better the water-repellent performance. However, due to the water resistance of its own ester bond, PET polyester is difficult to degrade in the natural environment, so discarded PET textiles have a great impact on the environment.

[0003] Nonwoven fabric is a kind of non-woven fabric, which can directly form polymer slices, short fibers or filaments into a net through airflow or mechanical means, and then reinforced by water spunlace, needle punching or hot rolling, and finally formed into a non-woven fabric after finishing. Among them, the spunbond method is the most advantageous, with a simple manufacturing method, high production efficiency, and can be produced continuously and in large quantities. The nonwoven fabric produced by the spunbond method has excellent mechanical properties, with good tensile strength, elongation at break, and tear strength. However, compared with woven fabrics, its strength and durability are poor. It is necessary to adjust the process to improve the strength of spunbond nonwoven fabrics.

[0004] Patent CN101476213B discloses a process for producing recycled PET hot-rolled spunbond nonwoven fabrics, which processes and reprocesses recycled PET bottles. However, the preparation method is complicated, and the produced PET hot-rolled spunbond nonwoven fabrics are not biodegradable, making them difficult to recycle and reuse, and failing to fundamentally solve the environmental problems caused by PET waste.

[0005] Patent CN116949687A discloses a method for preparing biodegradable spunbond nonwoven fabrics, using PHA as biodegradable copolyester particles. The prepared nonwoven fabrics can be naturally degraded in nature and can be completely composted and biodegraded. The spunbond nonwoven fabrics are prepared through a spunbond process, and have good mechanical properties and can be used as facial mask base fabrics. However, the cost is relatively high.

[0006] Patent CN111593484A discloses a method for making easily degradable SMS spunbond nonwoven fabrics, which uses PLA (polylactic acid) as raw material, with the upper and lower layers being spunbond nonwoven fabrics, the middle being meltblown nonwoven fabric, and finally the three layers of nonwoven fabrics being hot-rolled and pressed into shape. However, the preparation method is relatively complicated and the price is relatively high.

[0007] Therefore, an ideal solution is needed. Summary of the invention

[0008] In order to overcome the problem of poor degradation ability or mechanical properties of PET textiles, the present invention provides a biodegradable PET-based spunbond nonwoven fabric and a preparation method thereof, and obtains a biodegradable PET-based spunbond nonwoven fabric with excellent mechanical properties by adjusting the polyester monomer components and spunbond spinning process parameters.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions: A preparation method of a biodegradable PET-based spunbonded nonwoven fabric comprises the following steps: melt-extrude, spin, draw, lay nets and hot-roll consolidate a PET-based degradable polyester; the monomers of the PET-based degradable polyester are terephthalic acid, ethylene glycol and a third monomer in a molar ratio of 1: (0.8-1.5): (0.08-0.4); the third monomer is a dibasic acid or a hydroxy acid with a carbon chain length of 2-6 carbons; the melt index of the PET-based degradable polyester is 60-110 g / 10 min; the air flow velocity of the drawing is 3000-5000 m / min; the speed of the laying net is 5-40 m / min; and the temperature of the hot rolling is 70-85° C.

[0010] By copolymerizing terephthalic acid, ethylene glycol and a third monomer, a PET-based copolyester with biodegradable properties can be synthesized. The change in the ratio of aliphatic monomers to aromatic monomers in the polyester chain segment greatly affects the hardness and crystallization properties of the copolyester chain structure, and the hardness and crystallization properties of the chain segment directly affect the mechanical properties of the material. The melt index of the polyester must be controlled within the range of 60 to 110 g / 10 min to be suitable for the spunbond process, and the polyester crystal structure within this range is beneficial to subsequent degradation.

[0011] The appropriate drafting process can improve the breaking strength of the fiber, reduce the elongation at break, and improve the wear resistance and fatigue strength of various deformations. Therefore, the present invention adjusts the metering pump speed, drafting air flow speed, laying speed and other processes to fully draft the fiber, and the crystallinity of the fiber is also improved, and the orientation and structure of the fiber tend to be stable. Heat setting can eliminate the internal stress of the fiber and improve the dimensional stability of the fiber. Therefore, the present invention adjusts the hot rolling process to stably produce biodegradable PET-based single S spunbond nonwoven fabrics.

[0012] As preferably, the third monomer is one of adipic acid, succinic acid, glycolic acid, and lactic acid. The polylactic acid (PLA) polymerized using lactic acid is nontoxic and has excellent biodegradability and biocompatibility, and it can be naturally decomposed by the microorganisms in the environment, reducing environmental pollution. Its high polymer of glycolic acid has good degradability in soil and water, and compared with degradable polymers such as PLA, PCL, PBS, it has significant degradation promotion, and its fat chain is shorter, has good hydrophilicity, and can effectively improve the hydrophilicity of polymer.

[0013] The method for preparing PET-based degradable polyester comprises the following steps: (1) uniformly mixing the monomer and the titanium catalyst, and performing an esterification reaction at 200 to 240° C. and 60 to 400 kPa nitrogen pressure for 2 to 5 hours to obtain an esterified product; (2) polycondensing the esterified product, phosphorus stabilizer and antioxidant at 240-260° C. and under a vacuum environment below 200 Pa for 3-8 hours to obtain a PET-based biodegradable polyester.

[0014] Preferably, the titanium-based catalyst is one of tetrabutyl titanate, isopropyl titanate, and potassium titanium oxalate; the phosphorus stabilizer is one of phosphoric acid, triphenyl phosphate, and triphenyl phosphite; and the antioxidant is one of antioxidant 1010, antioxidant 168, antioxidant THP-24, and antioxidant 618.

[0015] Preferably, the PET-based degradable polyester is in the form of chips and is vacuum dried.

[0016] Preferably, the melt extrusion is as follows: the PET-based biodegradable polyester is melted by an extruder, extruded from an extrusion die, filtered by a filter device, and then the melt is conveyed by a metering pump for spinning; the melting temperature of the extruder is 240-300°C, the temperature of the die is 245-300°C, the temperature of the metering pump is 260-310°C, and the rotation speed of the metering pump is 15-40rpm.

[0017] Preferably, the spinning speed is 800 to 2000 m / min.

[0018] Preferably, the drawing is tubular drawing.

[0019] The present invention also claims a biodegradable PET-based spunbonded nonwoven fabric prepared by the method.

[0020] Preferably, the biodegradable PET-based spunbonded nonwoven fabric has a transverse tensile strength of 14 to 140 N / 50 mm and a longitudinal tensile strength of 17 to 150 N / 50 mm; according to GB / T 19277.2-2013 composting degradation rate, the degradation rate exceeds 80% within 180 days.

[0021] Therefore, the beneficial effects of the present invention are: (1) The PET-based biodegradable polyester copolymerized in the present invention has a low production cost. Its raw material cost is lower than that of biodegradable materials such as PLA, PHA, and PCL. The raw materials are easy to obtain and have low costs. In addition, compared with PLA and PHA, the present invention can be produced and processed using traditional polymerization spinning equipment without the need for biological fermentation.

[0022] (2) Compared with textiles made from recycled PET, the present invention has a simple production process, and the spunbonded nonwoven fabric made from recycled PET is difficult to recycle, and the environmental pollution problem caused by it has not been fundamentally solved. The present invention can be naturally degraded in nature and can achieve compost biodegradation with a degradation rate of about 80% in 180 days, which is environmentally friendly.

[0023] (3) The present invention can achieve degradation in the natural environment while meeting the performance requirements. By adjusting the spunbond spinning process, exploring the metering pump speed, drafting air flow speed, laying speed, etc., the UDY yarn is optimally drafted, the fiber's breaking strength is improved, the elongation at break is reduced, the wear resistance and fatigue strength of various deformations are improved, and then by adjusting the hot rolling temperature, the internal stress of the fiber is eliminated, the fiber dimensional stability is improved, and the mechanical properties are improved. It can be applied to wiping cloths, beauty products, floral packaging cloths and shopping bags, etc., and has good application prospects. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below through specific embodiments.

[0025] In the present invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or are commonly used in the art. The methods in the embodiments, unless otherwise specified, are all conventional methods in the art. Unless otherwise specified, parts are all weight parts, temperatures are expressed in ° C or at ambient temperature, and pressures are atmospheric pressure or near atmospheric pressure. There are many variations and combinations of reaction conditions (such as component concentrations, desired solvents, solvent mixtures, temperatures, pressures, and other reaction ranges) and conditions that can be used to optimize the purity and yield of the product obtained by the method, and only reasonable routine experiments will be required to optimize such method conditions.

[0026] Example A method for preparing a biodegradable PET-based spunbonded nonwoven fabric comprises the following steps: (1) Preparation of PET-based degradable polyester (1.1) A titanium catalyst and terephthalic acid, ethylene glycol and a third monomer in a molar ratio of 1: (0.8-1.5): (0.08-0.4) are uniformly mixed, wherein the third monomer is a dibasic acid or a hydroxy acid with a carbon chain length of 2-6 carbons, and an esterification reaction is carried out at 200-240° C. and 60-400 kPa nitrogen pressure for 2-5 hours to obtain an esterified product. The titanium catalyst is preferably one of tetrabutyl titanate, isopropyl titanate and potassium titanium oxalate; the third monomer is preferably one of adipic acid, succinic acid, glycolic acid and lactic acid.

[0027] (1.2) The esterified product obtained in step (1.1) and the phosphorus stabilizer and antioxidant are subjected to polycondensation reaction at 240-260° C. and a vacuum environment below 200 Pa for 3-8 hours, and the viscosity is controlled to be 0.65 dL / g and the melt index is 60-110 g / 10 min to obtain a PET-based biodegradable polyester. The phosphorus stabilizer is one of phosphoric acid, triphenyl phosphate, and triphenyl phosphite, and the antioxidant is one of antioxidant 1010, antioxidant 168, antioxidant THP-24, and antioxidant 618.

[0028] (1.3) The PET-based biodegradable polyester obtained in step (1.2) is sliced, and the slices are dried in a vacuum drum drying oven at 100° C. and then sealed and stored.

[0029] (2) Preparation of biodegradable PET-based spunbond nonwoven fabric (2.1) The PET-based biodegradable polyester chips obtained in step (1.3) are melted in an extruder at 240-300° C., extruded from an extrusion die at 245-300° C., filtered through a filter device, and then conveyed by a metering pump at 260-310° C. for spinning. The metering pump rotates at 15-40 rpm and the spinning speed is 800-2000 m / min.

[0030] (2.2) The filament bundle formed by spinning is stretched, and the stretching method is preferably tubular stretching, and the stretching air flow velocity is 3000-5000 m / min; the filaments are laid at a speed of 5-40 m / min, hot-rolled and consolidated at 70-85° C., and then wound to obtain a biodegradable PET-based single S spunbond nonwoven fabric.

[0031] The biodegradable PET-based single S spunbonded nonwoven fabric prepared by the above preparation method has a transverse tensile strength of 14-140N / 50mm and a longitudinal tensile strength of 17-150N / 50mm; according to GB / T 19277.2-2013 composting degradation rate, the degradation rate exceeds 80% in 180 days.

[0032] Example 1 A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to their weight proportions, 61 parts of terephthalic acid, 30 parts of ethylene glycol, 8 parts of glycolic acid and 0.1 parts of tetrabutyl titanate were uniformly mixed, and an esterification reaction was carried out at 220° C. and a nitrogen pressure of 100 kPa for 4 hours to obtain an esterified product; the esterified product, 0.3 parts of phosphoric acid and 0.6 parts of antioxidant THP-24 were subjected to a condensation reaction at 250° C. and a vacuum environment of less than 40 Pa for 6 hours, and the viscosity was controlled to be 0.65 dL / g and the melt index was controlled to be 60-110 g / 10 min, thereby obtaining a PET-based biodegradable polyester.

[0033] (2) The prepared PET-based biodegradable polyester chips are dried in a vacuum drum drying oven at 100° C. and then sealed and stored. The dried chips are melted at 255° C. by an extruder, extruded from an extrusion die, filtered through a filter device, and then the melt is transported by a metering pump for spinning. The die temperature is 260° C., the metering pump temperature is 270° C., the metering pump speed is 15 rpm, the spinning speed is 1000 m / min, and the formed filament bundles are drawn at a drawing air flow speed of 5000 m / min. After filament laying and hot rolling consolidation, the laying speed is 40 m / min, the hot rolling temperature is 70° C., and the biodegradable PET-based single S spunbond nonwoven fabric is obtained by winding.

[0034] Example 2 A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to their weight proportions, 68 parts of terephthalic acid, 26 parts of ethylene glycol, 5 parts of adipic acid and 0.1 parts of tetrabutyl titanate were uniformly mixed, and an esterification reaction was carried out at 200° C. and 400 kPa nitrogen pressure for 2 h to obtain an esterified product; the esterified product, 0.3 parts of phosphoric acid and 0.6 parts of antioxidant THP-24 were subjected to a condensation reaction at 240° C. and a vacuum environment below 40 Pa for 8 h, and the viscosity was controlled to be 0.65 dL / g and the melt index was controlled to be 60-110 g / 10 min, thereby obtaining a PET-based biodegradable polyester.

[0035] (2) The prepared PET-based biodegradable polyester chips are dried at 100° C. in a vacuum drum drying oven and then sealed and stored; the dried chips are melted at 255° C. in an extruder, extruded from an extrusion die, filtered through a filter device, and then the melt is transported by a metering pump for spinning, wherein the die temperature is 260° C., the metering pump temperature is 270° C., the metering pump speed is 15 rpm, the spinning speed is 2000 m / min, the formed filament bundle is drawn, the drawing air flow speed is 5000 m / min, and after filament laying and hot rolling consolidation, the laying speed is 40 m / min, the hot rolling temperature is 70° C., and the biodegradable PET-based single S spunbond nonwoven fabric is obtained by winding.

[0036] Example 3 A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to their weight proportions, 55 parts of terephthalic acid, 24 parts of ethylene glycol, 20 parts of lactic acid and 0.02 parts of tetrabutyl titanate were uniformly mixed, and an esterification reaction was carried out at 240° C. and 60 kPa nitrogen pressure for 2 h to obtain an esterified product; the esterified product, 0.6 parts of triphenyl phosphite and 0.38 parts of antioxidant 168 were subjected to a condensation reaction at 260° C. and a vacuum environment below 40 Pa for 3 h, and the viscosity was controlled to be 0.65 dL / g and the melt index was controlled to be 60-110 g / 10 min, thereby obtaining a PET-based biodegradable polyester.

[0037] (2) The prepared PET-based biodegradable polyester chips are dried in a vacuum drum drying oven at 100° C. and then sealed and stored. The dried chips are melted at 255° C. by an extruder, extruded from an extrusion die, filtered through a filter device, and then the melt is transported by a metering pump for spinning. The die temperature is 260° C., the metering pump temperature is 270° C., the metering pump speed is 40 rpm, the spinning speed is 800 m / min, and the formed filament bundles are drawn at a drawing air flow speed of 3000 m / min. After filament laying and hot rolling consolidation, the laying speed is 5 m / min, the hot rolling temperature is 85° C., and the biodegradable PET-based single S spunbond nonwoven fabric is obtained by winding.

[0038] Example 4 A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to their weight proportions, 61 parts of terephthalic acid, 30 parts of ethylene glycol, 8 parts of adipic acid and 0.06 parts of isopropyl titanate were uniformly mixed, and an esterification reaction was carried out at 220° C. and 200 kPa nitrogen pressure for 3 h to obtain an esterified product; the esterified product, 0.5 parts of triphenyl phosphate and 0.44 parts of antioxidant 1010 were subjected to a condensation reaction at 250° C. and a vacuum environment below 40 Pa for 6 h, and the viscosity was controlled to be 0.65 dL / g and the melt index was controlled to be 60-110 g / 10 min, thereby obtaining a PET-based biodegradable polyester.

[0039] (2) The prepared PET-based biodegradable polyester chips are dried at 100° C. in a vacuum drum drying oven and then sealed and stored; the dried chips are melted at 260° C. in an extruder, extruded from an extrusion die, filtered through a filter device, and then the melt is transported by a metering pump for spinning, wherein the die temperature is 265° C., the metering pump temperature is 275° C., the metering pump speed is 25 rpm, the spinning speed is 1200 m / min, the formed filament bundle is drawn, the drawing air flow speed is 4000 m / min, and after filament laying and hot rolling consolidation, the laying speed is 20 m / min, the hot rolling temperature is 75° C., and the biodegradable PET-based single S spunbond nonwoven fabric is wound.

[0040] Example 5 A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to their weight proportions, 61 parts of terephthalic acid, 30 parts of ethylene glycol, 8 parts of glycolic acid and 0.06 parts of tetrabutyl titanate were uniformly mixed, and an esterification reaction was carried out at 220° C. and 300 kPa nitrogen pressure for 4 hours to obtain an esterified product; the esterified product, 0.6 parts of triphenyl phosphite and 0.34 parts of antioxidant 168 were subjected to a condensation reaction at 250° C. and a vacuum environment below 40 Pa for 5 hours, and the viscosity was controlled to be 0.65 dL / g and the melt index was controlled to be 60-110 g / 10 min, thereby obtaining a PET-based biodegradable polyester.

[0041] (2) The prepared PET-based biodegradable polyester chips are dried in a vacuum drum drying oven at 100° C. and then sealed and stored. The dried chips are melted at 255° C. by an extruder, extruded from an extrusion die, filtered through a filter device, and then the melt is transported by a metering pump for spinning. The die temperature is 260° C., the metering pump temperature is 270° C., the metering pump speed is 40 rpm, the spinning speed is 1400 m / min, and the formed filament bundles are drawn at a drawing air flow speed of 3000 m / min. After filament laying and hot rolling consolidation, the laying speed is 5 m / min, the hot rolling temperature is 85° C., and the biodegradable PET-based single S spunbond nonwoven fabric is obtained by winding.

[0042] Example 6 A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to the weight ratio, 59 parts of terephthalic acid, 28 parts of ethylene glycol, 12 parts of lactic acid and 0.04 parts of potassium titanium oxalate were uniformly mixed, and an esterification reaction was carried out at 200° C. and 60 kPa nitrogen pressure for 5 hours to obtain an esterified product; the esterified product, 0.3 parts of phosphoric acid and 0.66 parts of antioxidant THP-24 were subjected to condensation reaction at 240° C. and a vacuum environment below 40 Pa for 8 hours, and the viscosity was controlled to be 0.65 dL / g and the melt index was 60-110 g / 10 min to obtain a PET-based biodegradable polyester.

[0043] (2) The prepared PET-based biodegradable polyester chips are dried at 100° C. in a vacuum drum drying oven and then sealed and stored; the dried chips are melted at 240° C. in an extruder, extruded from an extrusion die, filtered through a filter device, and then the melt is transported by a metering pump for spinning, wherein the die temperature is 250° C., the metering pump temperature is 260° C., the metering pump speed is 15 rpm, the spinning speed is 1600 m / min, the formed filament bundle is drawn, the drawing air flow speed is 5000 m / min, and after filament laying and hot rolling consolidation, the laying speed is 40 m / min, the hot rolling temperature is 70° C., and the biodegradable PET-based single S spunbond nonwoven fabric is obtained by winding.

[0044] Example 7 A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to their weight proportions, 59 parts of terephthalic acid, 28 parts of ethylene glycol, 12 parts of succinic acid and 0.04 parts of tetrabutyl titanate were uniformly mixed, and an esterification reaction was carried out at 240° C. and 400 kPa nitrogen pressure for 2 h to obtain an esterified product; the esterified product, 0.5 parts of triphenyl phosphate and 0.46 parts of antioxidant 618 were subjected to a condensation reaction at 260° C. and a vacuum environment below 40 Pa for 3 h, and the viscosity was controlled to be 0.65 dL / g and the melt index was controlled to be 60-110 g / 10 min, thereby obtaining a PET-based biodegradable polyester.

[0045] (2) The prepared PET-based biodegradable polyester chips are dried in a vacuum drum drying oven at 100° C. and then sealed and stored. The dried chips are melted at 300° C. by an extruder, extruded from an extrusion die, filtered through a filter device, and then the melt is transported by a metering pump for spinning. The die temperature is 300° C., the metering pump temperature is 310° C., the metering pump speed is 25 rpm, the spinning speed is 1800 m / min, and the formed filament bundles are drawn at a drawing air flow speed of 4000 m / min. After filament laying and hot rolling consolidation, the laying speed is 20 m / min, the hot rolling temperature is 75° C., and the biodegradable PET-based single S spunbond nonwoven fabric is obtained by winding.

[0046] Comparative Example 1 A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to the weight ratio, 68 parts of terephthalic acid, 26 parts of ethylene glycol, 2 parts of glycolic acid and 0.1 parts of tetrabutyl titanate are uniformly mixed, and an esterification reaction is carried out at 200-240° C. and 60-400 kPa nitrogen pressure for 2-5 hours to obtain an esterified product; the esterified product, 0.3 parts of phosphoric acid and 0.6 parts of antioxidant THP-24 are subjected to a condensation reaction at 240-260° C. and a vacuum environment below 40 Pa for 3-8 hours, and the viscosity is controlled to be 0.65 dL / g and the melt index is 60-110 g / 10 min to obtain a PET-based biodegradable polyester.

[0047] (2) The prepared PET-based biodegradable polyester chips are dried in a vacuum drum drying oven at 100° C. and then sealed and stored. The dried chips are melted at 255° C. by an extruder, extruded from an extrusion die, filtered through a filter device, and then the melt is transported by a metering pump for spinning. The die temperature is 260° C., the metering pump temperature is 270° C., the metering pump speed is 15 rpm, the spinning speed is 1000 m / min, and the formed filament bundles are drawn at a drawing air flow speed of 5000 m / min. After filament laying and hot rolling consolidation, the laying speed is 40 m / min, the hot rolling temperature is 70° C., and the biodegradable PET-based single S spunbond nonwoven fabric is obtained by winding.

[0048] Comparative Example 2 A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to the weight ratio, 55 parts of terephthalic acid, 24 parts of ethylene glycol, 20 parts of glycolic acid and 0.06 parts of tetrabutyl titanate are uniformly mixed, and an esterification reaction is carried out at 200-240° C. and 60-400 kPa nitrogen pressure for 2-5 hours to obtain an esterified product; the esterified product, 0.6 parts of triphenyl phosphite and 0.34 parts of antioxidant 168 are subjected to a condensation reaction at 240-260° C. and a vacuum environment below 40 Pa for 3-8 hours, and the viscosity is controlled to be 0.65 dL / g and the melt index is 60-110 g / 10 min to obtain a PET-based biodegradable polyester.

[0049] (2) The prepared PET-based biodegradable polyester chips are dried in a vacuum drum drying oven at 100° C. and then sealed and stored. The dried chips are melted at 255° C. by an extruder, extruded from an extrusion die, filtered through a filter device, and then the melt is transported by a metering pump for spinning. The die temperature is 260° C., the metering pump temperature is 270° C., the metering pump speed is 40 rpm, the spinning speed is 1400 m / min, and the formed filament bundles are drawn at a drawing air flow speed of 3000 m / min. After filament laying and hot rolling consolidation, the laying speed is 5 m / min, the hot rolling temperature is 85° C., and the biodegradable PET-based single S spunbond nonwoven fabric is obtained by winding.

[0050] Comparative Example 3 The difference from Example 1 is that the temperature of the metering pump in the spinning process of step (2) is too high, as follows: A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to their weight proportions, 61 parts of terephthalic acid, 30 parts of ethylene glycol, 8 parts of glycolic acid and 0.1 parts of tetrabutyl titanate were uniformly mixed, and an esterification reaction was carried out at 220° C. and a nitrogen pressure of 100 kPa for 4 hours to obtain an esterified product; the esterified product, 0.3 parts of phosphoric acid and 0.6 parts of antioxidant THP-24 were subjected to a condensation reaction at 250° C. and a vacuum environment of less than 40 Pa for 6 hours, and the viscosity was controlled to be 0.65 dL / g and the melt index was controlled to be 60-110 g / 10 min, thereby obtaining a PET-based biodegradable polyester.

[0051] (2) The PET-based biodegradable polyester chips prepared in Example 1 were dried in a vacuum drum drying oven at 100°C and then sealed and stored. The dried chips were melted at 300°C by an extruder, extruded from an extrusion die, filtered by a filter device, and then the melt was transported by a metering pump for spinning. The die temperature was 330°C, the metering pump temperature was 340°C, the metering pump speed was 15 rpm, and the spinning speed was 1000 m / min. Because the spinning temperature was too high, droplets appeared during the spinning process, and melt continued to flow out of the spinneret, resulting in unstable spinning.

[0052] Comparative Example 4 The difference from Example 1 is that the drafting air flow velocity in step (2) is too high, as follows: A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to their weight proportions, 61 parts of terephthalic acid, 30 parts of ethylene glycol, 8 parts of glycolic acid and 0.1 parts of tetrabutyl titanate were uniformly mixed, and an esterification reaction was carried out at 220° C. and a nitrogen pressure of 100 kPa for 4 hours to obtain an esterified product; the esterified product, 0.3 parts of phosphoric acid and 0.6 parts of antioxidant THP-24 were subjected to a condensation reaction at 250° C. and a vacuum environment of less than 40 Pa for 6 hours, and the viscosity was controlled to be 0.65 dL / g and the melt index was controlled to be 60-110 g / 10 min, thereby obtaining a PET-based biodegradable polyester.

[0053] (2) The PET-based biodegradable polyester chips prepared in Example 1 were dried in a vacuum drum drying oven at 100°C and then sealed and stored. The dried chips were melted at 255°C by an extruder, extruded from an extrusion die, filtered by a filter device, and then the melt was transported by a metering pump for spinning. The die temperature was 260°C, the metering pump temperature was 270°C, the metering pump speed was 15rpm, and the spinning speed was 1000m / min. The formed filaments were drawn at a drawing air flow speed of 6000m / min. After filament laying and hot rolling consolidation, the laying speed was 40m / min, the hot rolling temperature was 70°C, and the biodegradable PET-based single S spunbond nonwoven fabric was wound. Because the drawing air flow speed was too fast, the drawing filaments were easily broken, resulting in uneven laying. The uniformity of the prepared biodegradable PET-based single S spunbond nonwoven fabric was poor, and the physical property test results had a large deviation. Moreover, according to the measured data, the 180-day degradation rate is less than 70%, because the non-woven fabric produced by the excessively fast drafting airflow speed has a high density, which is not conducive to degradation.

[0054] Comparative Example 5 The difference from Example 1 is that in step (2), the metering pump speed is too low and the web laying speed is too high during the spinning process. Specifically, a method for preparing a biodegradable PET-based spunbond nonwoven fabric comprises the following steps: (1) According to their weight proportions, 61 parts of terephthalic acid, 30 parts of ethylene glycol, 8 parts of glycolic acid and 0.1 parts of tetrabutyl titanate were uniformly mixed, and an esterification reaction was carried out at 220° C. and a nitrogen pressure of 100 kPa for 4 hours to obtain an esterified product; the esterified product, 0.3 parts of phosphoric acid and 0.6 parts of antioxidant THP-24 were subjected to a condensation reaction at 250° C. and a vacuum environment of less than 40 Pa for 6 hours, and the viscosity was controlled to be 0.65 dL / g and the melt index was controlled to be 60-110 g / 10 min, thereby obtaining a PET-based biodegradable polyester.

[0055] (2) The PET-based biodegradable polyester chips prepared in Example 1 were dried in a vacuum drum drying oven at 100°C and then sealed and stored. The dried chips were melted at 255°C by an extruder, extruded from an extrusion die, filtered by a filter device, and then the melt was transported by a metering pump for spinning. The die temperature was 260°C, the metering pump temperature was 270°C, the metering pump speed was 11rpm, and the spinning speed was 1000m / min. The formed filaments were drafted at a drafting air flow rate of 5000m / min. After filament laying and hot rolling consolidation, the laying speed was 60m / min and the hot rolling temperature was 70°C. The biodegradable PET-based single S spunbond nonwoven fabric was wound. Because the metering pump speed was too slow, the melt delivery amount was small, and the laying speed was too fast, the prepared biodegradable PET-based single S spunbond nonwoven fabric was uneven, and the physical property test results had large deviations.

[0056] Comparative Example 6 The difference from Example 1 is that the hot rolling temperature in step (2) is too high, as follows: A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to their weight proportions, 61 parts of terephthalic acid, 30 parts of ethylene glycol, 8 parts of glycolic acid and 0.1 parts of tetrabutyl titanate were uniformly mixed, and an esterification reaction was carried out at 220° C. and a nitrogen pressure of 100 kPa for 4 hours to obtain an esterified product; the esterified product, 0.3 parts of phosphoric acid and 0.6 parts of antioxidant THP-24 were subjected to a condensation reaction at 250° C. and a vacuum environment of less than 40 Pa for 6 hours, and the viscosity was controlled to be 0.65 dL / g and the melt index was controlled to be 60-110 g / 10 min, thereby obtaining a PET-based biodegradable polyester.

[0057] (2) The PET-based biodegradable polyester chips prepared in Example 1 were dried in a vacuum drum drying oven at 100°C and then sealed and stored. The dried chips were melted in an extruder at 255°C, extruded from an extrusion die, filtered through a filter device, and then transported by a metering pump for spinning. The die temperature was 260°C, the metering pump temperature was 270°C, the metering pump speed was 15 rpm, the spinning speed was 1000 m / min, and the formed filaments were drawn at a drawing air flow rate of 5000 m / min. After the filaments were laid and hot rolled for consolidation, the hot rolling temperature was too high, the hot rolling process was easy to wrap around the roller, the winding was difficult, the cooling speed was slow, and it was not easy to form.

[0058] Comparative Example 7 The difference from Example 1 is that the molar amount of ethylene glycol in step (1) is 0.5 times that of terephthalic acid, specifically as follows: A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to their weight proportions, 61 parts of terephthalic acid, 11.4 parts of ethylene glycol, 8 parts of glycolic acid and 0.1 parts of tetrabutyl titanate were uniformly mixed, and an esterification reaction was carried out at 220° C. and a nitrogen pressure of 100 kPa for 4 hours to obtain an esterified product; the esterified product, 0.3 parts of phosphoric acid and 0.6 parts of antioxidant THP-24 were subjected to a condensation reaction at 250° C. and a vacuum environment of less than 40 Pa for 6 hours, and the viscosity was controlled to be 0.65 dL / g, thereby obtaining a PET-based biodegradable polyester.

[0059] (2) The prepared PET-based biodegradable polyester chips are dried in a vacuum drum drying oven at 100° C. and then sealed and stored. The dried chips are melted at 255° C. by an extruder, extruded from an extrusion die, filtered through a filter device, and then the melt is transported by a metering pump for spinning. The die temperature is 260° C., the metering pump temperature is 270° C., the metering pump speed is 15 rpm, the spinning speed is 1000 m / min, and the formed filament bundles are drawn at a drawing air flow speed of 5000 m / min. After filament laying and hot rolling consolidation, the laying speed is 40 m / min, the hot rolling temperature is 70° C., and the biodegradable PET-based single S spunbond nonwoven fabric is obtained by winding.

[0060] Comparative Example 8 The difference from Example 1 is that the molar amount of ethylene glycol in step (1) is twice that of terephthalic acid, specifically as follows: A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to their weight proportions, 61 parts of terephthalic acid, 45.6 parts of ethylene glycol, 8 parts of glycolic acid and 0.1 parts of tetrabutyl titanate were uniformly mixed, and an esterification reaction was carried out at 220° C. and 100 kPa nitrogen pressure for 4 hours to obtain an esterified product; the esterified product, 0.3 parts of phosphoric acid and 0.6 parts of antioxidant THP-24 were subjected to a condensation reaction at 250° C. and a vacuum environment below 40 Pa for 6 hours, and the viscosity was controlled to be 0.65 dL / g, thereby obtaining a PET-based biodegradable polyester.

[0061] (2) The prepared PET-based biodegradable polyester chips are dried in a vacuum drum drying oven at 100° C. and then sealed and stored. The dried chips are melted at 255° C. by an extruder, extruded from an extrusion die, filtered through a filter device, and then the melt is transported by a metering pump for spinning. The die temperature is 260° C., the metering pump temperature is 270° C., the metering pump speed is 15 rpm, the spinning speed is 1000 m / min, and the formed filament bundles are drawn at a drawing air flow speed of 5000 m / min. After filament laying and hot rolling consolidation, the laying speed is 40 m / min, the hot rolling temperature is 70° C., and the biodegradable PET-based single S spunbond nonwoven fabric is obtained by winding.

[0062] Comparative Example 9 The difference from Example 2 is that the carbon chain of the third monomer in step (1) is too long, as follows: A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, comprising the following steps: (1) According to their weight proportions, 68 parts of terephthalic acid, 26 parts of ethylene glycol, 6 parts of suberic acid and 0.1 parts of tetrabutyl titanate were uniformly mixed, and an esterification reaction was carried out at 200° C. and 400 kPa nitrogen pressure for 2 h to obtain an esterified product; the esterified product, 0.3 parts of phosphoric acid and 0.6 parts of antioxidant THP-24 were subjected to a condensation reaction at 240° C. and a vacuum environment below 40 Pa for 8 h, and the viscosity was controlled to be 0.65 dL / g, thereby obtaining a PET-based biodegradable polyester.

[0063] (2) The prepared PET-based biodegradable polyester chips are dried at 100° C. in a vacuum drum drying oven and then sealed and stored; the dried chips are melted at 255° C. in an extruder, extruded from an extrusion die, filtered through a filter device, and then the melt is transported by a metering pump for spinning, wherein the die temperature is 260° C., the metering pump temperature is 270° C., the metering pump speed is 15 rpm, the spinning speed is 2000 m / min, the formed filament bundle is drawn, the drawing air flow speed is 5000 m / min, and after filament laying and hot rolling consolidation, the laying speed is 40 m / min, the hot rolling temperature is 70° C., and the biodegradable PET-based single S spunbond nonwoven fabric is obtained by winding.

[0064] Performance Testing The performance of the biodegradable PET-based single S spunbonded nonwoven fabrics prepared in each embodiment and comparative example was tested, and the test method was as follows: ① The degradation rate was set according to the composting conditions of GB / T 19277.2-2013, and the composting degradation rate of the product was tested; ② The physical properties were measured according to the surface density (unit area mass) of nonwoven fabrics in GB / T24218.1 and the breaking strength and breaking elongation of nonwoven fabrics in GB / T24218.3. The results are shown in the following table. <![CDATA[Grammage g / m 2 > Transverse tensile strength N / 50mm Longitudinal tensile strength N / 50mm 180 days degradation rate % Example 1 40.2 15.7 19.2 85.7 Example 2 45.2 22.3 25.8 80.9 Example 3 220.7 127.8 136.4 95.7 Example 4 110.8 46.4 50.5 83.2 Example 5 238.5 140.8 150.2 82.6 Example 6 36.3 14.3 17.3 86.5 Example 7 106.8 43.9 46.2 84.1 Comparative Example 1 35.6 17.9 20.7 60.5 Comparative Example 2 250.6 65.3 73.5 100% in 100 days Comparative Example 7 40.9 14.1 18.0 76.3 Comparative Example 8 41.2 12.3 15.9 89.6 Comparative Example 9 46.1 - - 72.8

[0065] It can be seen from the above table that the biodegradable PET-based single S spunbonded nonwoven fabrics prepared in various embodiments of the present invention have both excellent mechanical properties and degradation properties.

[0066] Compared with Example 1: (1) In comparative example 1, the dosage of the third monomer is too low, and the degradation rate of the nonwoven fabric is slow. However, in comparative example 2, the dosage of the third monomer is too high, which leads to a serious decrease in the mechanical properties of the nonwoven fabric. Therefore, the dosage of the third monomer should be within a reasonable range.

[0067] (2) The spunbond process parameters of Comparative Examples 3-6 are not within the preferred range and qualified and uniform nonwoven fabrics cannot be produced.

[0068] (3) In comparative example 7, the amount of ethylene glycol used is too low. On the one hand, the amount of ethylene glycol used relative to terephthalic acid is too low, and the mass fraction of polyester generated in the polyester polymerization process gradually decreases, while the mass fraction of oligomers gradually increases; on the other hand, the amount of ethylene glycol used relative to the third monomer is too low, resulting in the polyester crystal structure becoming more regular and stable, and water molecules and the like are difficult to enter the internal structure of the crystal region, resulting in a slow degradation rate. In comparative example 8, the amount of ethylene glycol used is too high, which will reduce the light resistance and heat resistance of the non-woven fabric, and is conducive to the degradation of the non-woven fabric; however, too high an ethylene glycol content will reduce the mechanical properties of the non-woven fabric.

[0069] It is worth noting that in the actual experimental process, it is very difficult to determine the dosage ratio of the three monomers. There are many variables involved, and the three need to cooperate with each other to achieve the best effect.

[0070] Compared with Example 2, the carbon chain of the third monomer in Comparative Example 9 is too long, and entanglement leads to high molecular density, making it difficult for water molecules and the like to enter the internal structure of the crystalline region, which also reduces the degradation rate.

[0071] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a biodegradable PET-based spunbonded nonwoven fabric, characterized in that: The PET-based degradable polyester is melt-extruded, spun, drawn, laid, and hot-rolled for consolidation; the monomers of the PET-based degradable polyester are terephthalic acid, ethylene glycol, and a third monomer in a molar ratio of 1: (0.8-1.5): (0.08-0.4), the third monomer is a dibasic acid or a hydroxy acid with a carbon chain length of 2-6 carbons, and the melt index of the PET-based degradable polyester is 60-110 g / 10min; the air flow velocity of the drawing is 3000-5000 m / min; the laying speed is 5-40 m / min; and the hot rolling temperature is 70-85°C.

2. The method for preparing a biodegradable PET-based spunbonded nonwoven fabric according to claim 1, characterized in that: The third monomer is one of adipic acid, succinic acid, glycolic acid and lactic acid.

3. The method for preparing a biodegradable PET-based spunbonded nonwoven fabric according to claim 1, characterized in that: The preparation method of PET-based degradable polyester comprises the following steps: (1) The monomer and the titanium catalyst are uniformly mixed, and an esterification reaction is carried out at 200-240 °C and 60-400 kPa nitrogen pressure for 2-5 h to obtain an esterified product; (2) subjecting the esterified product to a condensation reaction with a phosphorus stabilizer and an antioxidant at 240-260° C. and a vacuum environment below 200 Pa for 3-8 hours to obtain a PET-based biodegradable polyester.

4. The method for preparing a biodegradable PET-based spunbonded nonwoven fabric according to claim 3, characterized in that: The titanium-based catalyst is one of tetrabutyl titanate, isopropyl titanate, and potassium titanium oxalate.

5. The method for preparing a biodegradable PET-based spunbonded nonwoven fabric according to claim 3 or 4, characterized in that: The phosphorus stabilizer is one of phosphoric acid, triphenyl phosphate, and triphenyl phosphite, and the antioxidant is one of antioxidant 1010, antioxidant 168, antioxidant THP-24, and antioxidant 618.

6. The method for preparing a biodegradable PET-based spunbonded nonwoven fabric according to claim 1, characterized in that: The PET-based biodegradable polyester is in the form of chips and is vacuum dried.

7. The method for preparing a biodegradable PET-based spunbonded nonwoven fabric according to claim 1, characterized in that: The melt extrusion is as follows: the PET-based biodegradable polyester is melted through an extruder, extruded from an extrusion die, filtered through a filtering device, and then the melt is transported through a metering pump for spinning; the melting temperature of the extruder is 240~300°C, the temperature of the die is 245~300°C, the temperature of the metering pump is 260~310°C, and the speed of the metering pump is 15~40 rpm.

8. The method for preparing a biodegradable PET-based spunbonded nonwoven fabric according to claim 1, 6 or 7, characterized in that: The spinning speed is 800~2000 m / min; the drawing is tubular drawing.

9. The PET-based spunbonded nonwoven fabric prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The transverse tensile strength of the biodegradable PET-based spunbond nonwoven fabric is 14~140 N / 50mm, and the longitudinal tensile strength is 17~150 N / 50mm; the composting degradation rate exceeds 80% in 180 days.