CN103469334B - A kind of preparation method of fluorine-containing PBT polyester POY fiber - Google Patents

Abstract

The invention relates to a method for preparing fluorine-containing PBT polyester POY fibers, comprising the preparation of fluorine-containing PBT polyester melts and the preparation of fluorine-containing PBT polyester POY fibers; Tetrafluoroterephthalic acid and 1,4-butanediol are used as raw materials and inhibitors are added to prepare fluorine-containing PBT polyester melt, which is directly extruded or made into slices, melted and extruded by a screw, cooled, and oiled And winding made fluorine-containing PBT polyester POY fiber. The monofilament fineness of the novel fluorine-containing PBT polyester POY fiber obtained by the invention is 0.5-3.0 dtex; the breaking strength is 2.0-3.5 cN/dtex; the breaking elongation is 90-130%. Due to the introduction of fluorine atoms, the superhydrophobic, oil-repellent and anti-fouling properties of polyester POY fiber are improved, and it has great prospects in the manufacture of waterproof clothing, dirt-resistant work clothes and work clothes in some special industries.

Description

A kind of preparation method of fluorine-containing PBT polyester POY fiber

technical field

The invention relates to a preparation method of fluorine-containing PBT polyester POY fiber, in particular to a preparation method of fluorine-containing PBT polyester POY fiber in which the hydrogen on the benzene ring is replaced by fluorine.

Background technique

Polyester is currently one of the most widely used synthetic polymers. As early as the 1940s, ethylene phthalate (PET) was synthesized and found to have excellent properties, and it is widely used In textile, packaging, medical and health, automobile, electronic appliances, safety protection, environmental protection and other fields. Pre-oriented yarn POY refers to the raw yarn that has not been stretched but can be directly stretched and deformed. It is required that the POY yarn can be stored for a long time and has certain structural stability and processability. During the processing of POY yarn, there are generally no problems such as difficulty in spinning, finished silk wool, low strength and uniform dyed cloth. The process has the advantages of high spinning winding speed, high hardness, heavy weight and cheap transportation; and good storage stability during spinning, suitable for DTY processing.

Polybutylene terephthalate (PBT) is a crystalline linear saturated polyester, which has the characteristics of high temperature resistance, humidity resistance, good electrical insulation performance, oil resistance, chemical corrosion resistance, and fast molding. Some of its application examples in the industry have shown its irreplaceable superiority in some aspects, and now it has become the next-generation polyamide (PA), polycarbonate (PC), polyoxymethylene (POM) and modified polyphenylene The fifth largest general-purpose engineering plastic after ether (MPPO), it is widely used in the automobile industry, electronic and electrical industry, food and medical equipment, packaging materials, environmental engineering, communication equipment, sports and leisure equipment, etc. With the continuous deepening of research on the structure and performance of PBT, not only have different grades and types of engineering plastics been developed, such as high-impact, heat-resistant, flame-retardant, etc., but also make its application in synthetic fibers more and more valued. PBT fiber has excellent elasticity, soft hand feeling, easy dyeing, and has the advantages of polyester, nylon and spandex.

With the progress of society and the improvement of people's living standards, the demand for the differentiation and functionalization of polyester fibers is getting higher and higher. Therefore, the modification of polyester has become particularly important. The purpose of polyester modification is not only to optimize the performance of ordinary polyester, but also to endow new polyester with differentiated functional characteristics through modification means. For example: antistatic, flame retardant, moisture wicking, antifouling and deodorant, etc. At present, the main new varieties of polyester are: antistatic polyester, high-strength wear-resistant polyester, cotton-like supersoft polyester, superhydrophobic polyester, antifouling polyester, etc.

At present, by introducing fluorine atoms into polymers, the surface properties of materials, such as hydrophobicity, oil repellency and anti-fouling properties, etc. are improved, and various functions are endowed to polyester materials. Because fluoropolymers usually have low surface energy, low coefficient of friction and non-adhesion, dust and dirt are difficult to adhere to, etc., so fluoropolymers have good anti-fouling and abrasion resistance. The current fluorine-containing polymers are mainly fluoroolefin polymers (for example: polytetrafluoroethylene, polyvinylidene fluoride, perfluoroethylene propylene copolymer, ethylene-tetrafluoroethylene copolymer, etc.); Research on fluoropolyethers and fluoropolyesters is relatively lagging behind.

Many scholars have conducted research on fluorine-containing compound-modified polyester, and achieved certain results. At present, polyesters are modified by fluorine-containing compounds mainly by adding fluorine-containing end-capping agents, or by adding fluorine-containing diols, fluorine-containing dibasic acids and other fluorine-containing compounds as the third monomer to modify polyester. In Chinese patent CN101139434A, the addition of fluorine-containing end-capping agent is adopted. Dimethyl isophthalate and butanediol are transesterified, and fluorine-containing end-capping agent N-hydroxyethyl perfluorooctylamide is added to prepare a fluorine-containing end-capping agent. Polyester material with low weight and good stain resistance. Hu Juan (Hu Juan. Molecular design and performance research of fluorine-containing polyester and photoresist waveguide materials [D]. Master's thesis, Jilin: Jilin University, 2007.) Using the principle of molecular design, by adding fluorine-containing diols In the way of copolymerization, terephthaloyl chloride, hexafluorobisphenol A and fluorine-containing octanediol are terpolymerized to form a new type of polyester with high fluorine content. The polyester has excellent properties and is applied to optical waveguide materials.

However, the application of these fluorine-containing polyesters to textiles and packaging materials has certain limitations. The main problem is that the prior art fluorine-containing polyesters have low molecular weight and cannot meet the requirements of spinning and film formation; At present, the existing technology mainly uses fluorine-containing finishing methods to endow fabrics with waterproof and anti-fouling functions, but the biggest disadvantage of this method is that it is difficult to solve the problems of timeliness, durability and wear resistance, and it is time-consuming and labor-intensive.

Therefore, the development of fluorine-containing polyester fibers for the modification of superhydrophobic, hydrophobic, oil-repellent, and antifouling properties of textile and packaging materials will have important theoretical significance and application value.

Contents of the invention

The invention provides a preparation method of fluorine-containing PBT polyester fiber, in particular a preparation method of fluorine-containing PBT polyester POY fiber in which the hydrogen on the benzene ring is replaced by fluorine. The fluorine-containing PBT polyester of the present invention introduces fluorine atoms into the main chain of the polymer, so the problems of time-consuming and labor-intensive problems can be well solved. The fluorine-containing PBT polyester described in the present invention is a fluorine-containing polyester obtained through esterification and polycondensation of terephthalic acid containing fluorine atoms on the benzene ring and 1,4-butanediol. Hydrophobic and antifouling modification of polyester by copolymerization can fundamentally solve the problems of timeliness, durability and wear resistance of hydrophobic and antifouling polyester.

The invention provides the following technical solutions:

The preparation of a fluorine-containing PBT polyester POY fiber is obtained by directly extruding a fluorine-containing PBT polyester melt or making slices through screw melt extrusion, cooling, oiling and winding; the fluorine-containing PBT polyester Esters refer to polybutylene terephthalate in which the hydrogen on the benzene ring is replaced by fluorine, which is polytetrafluorobutylene terephthalate, and its general structural formula is

Among them, n=70～150;

The monofilament fineness of the fluorine-containing PBT polyester POY fiber is 0.5-3.0 dtex; the breaking strength is 2.0-3.5 cN/dtex; the elongation at break is 90-130%;

The fluorine-containing PBT polyester POY fiber is prepared from the fluorine-containing PBT polyester melt through metering, extrusion, cooling, oiling and winding, wherein:

The extrusion temperature is 265-285°C;

The wind temperature of described cooling is 20～25 ℃;

The oiling rate of the oiling is 0.42～1.5%;

The winding speed is 2700～3200m/min;

The cooling is side blowing or ring blowing cooling, the temperature is 20°C-25°C, the relative humidity is 65%±5%, and the wind speed is 0.4-0.8m/s;

The oiling agent for oiling is an oiling agent for fluorine-containing polyester POY fibers, and its components are by weight:

Component A: random polyether, 50-60 parts;

Component B: polyethylene glycol fatty acid ester, 20-32 parts;

Component C: Potassium Phosphate, 10-15 parts;

Component D: perfluoroalkyl acrylate, 2-5 parts;

Oil preparation method:

Heat the random polyether to 40-60°C, stir and mix the polyethylene glycol fatty acid ester, phosphate potassium salt and perfluoroalkyl acrylate evenly, then add it to the random polyether, stir for 1-2 The POY oil agent for fluorine-containing polyester fibers can be obtained after 1 hour. When the oil agent is used, water is added to form an emulsion with a solid content of 8-10 wt%.

In the oil agent for fluorine-containing polyester POY fibers, component A random polyether is a smoothing agent: the substance is propylene glycol random polyether, butanol random polyether, lauric acid random polyether, lauryl alcohol One of random polyether and isomeric tridecyl alcohol random polyether. Atactic polyether has good heat resistance, less smoke, less coking, low flow temperature, good stability, low friction coefficient, strong shear resistance, low viscosity coefficient, and can form a very stable polymer on the surface of polyester fiber. Lubricant film with high adsorption and load-carrying capacity.

In the oil agent for fluorine-containing polyester POY fibers, component B polyethylene glycol fatty acid ester is an emulsifier: the substance is polyethylene glycol monolaurate, polyethylene glycol diester, polyethylene glycol One of glycol monooleate and polyethylene glycol diester. The oil film formed by polyethylene glycol fatty acid ester has good properties such as surface tension, interfacial tension, penetration, dispersibility and emulsification. Dynamic friction provides certain antistatic properties for fluorine-containing polyester fibers and improves bundling properties.

In the oil agent for fluorine-containing polyester POY fibers, component C phosphate potassium salt is an antistatic agent: the substance is potassium lauryl phosphate, isomeric tridecyl polyoxyethylene ether phosphate potassium salt and one of the potassium salts of tetradecyl alcohol phosphate. In the spinning process, a large amount of static electricity is easily generated. It is not enough to reduce the generation of static electricity through the smoothness of the fiber surface. It is also necessary to add an antistatic agent with superior performance. Phosphate potassium salt is a good antistatic agent. It is an anionic surfactant composed of hydrophobic groups and hydrophilic groups. The hydrophobic groups can combine with the surface of polyester fibers, and the hydrophilic groups Upward, a continuous water film of "surfactant-water" can be formed. It can effectively reduce the friction coefficient of fibers, increase the dielectric constant between friction bodies, and prevent static electricity from occurring.

In the oil agent for fluorine-containing polyester POY fibers, component D perfluoroalkyl acrylate is an additive: the substance is perfluorobutyl ethyl acrylate, perfluorohexyl ethyl acrylate, perfluorooctyl ethyl acrylate, One of methacrylate, perfluorobutylethyl methacrylate, perfluorohexylethyl methacrylate and perfluorooctylethyl methacrylate. Its function is to appropriately reduce the surface tension of the oil agent, making it easy to form a uniform continuous oil film. Fluorine-containing acrylate has low surface energy, adding an appropriate amount can reduce the surface tension of the oil, greatly increasing the wetting performance and penetration of the oil, making it easy to wet and spread the fibers and form a uniform oil film.

The fluorine-containing PBT polyester refers to polybutylene terephthalate in which the hydrogen on the benzene ring is replaced by fluorine, which is polytetrafluorobutylene terephthalate, and its general structural formula is

Wherein n=70～150.

The fluorine-containing PBT polyester melt refers to the melted fluorine-containing PBT polyester, and the preparation method of the fluorine-containing PBT polyester is divided into two steps of esterification reaction and polycondensation reaction; the specific steps are:

Described esterification reaction:

Tetrafluoroterephthalic acid and 1,4-butanediol are used as raw materials, and inhibitors are added to make a uniform slurry for esterification reaction; the esterification reaction is pressurized in a nitrogen atmosphere, and the pressure is controlled at less than 1KPa absolute pressure The temperature is 160-220°C, the time is 2-3 hours, and the distilled amount of esterification water reaches more than 90% of the theoretical value, which is the end point of the esterification reaction;

Described suppressor is a kind of in magnesium oxide, silicon oxide, calcium oxide, zinc oxide and manganese oxide; Because there is fluorine atom on the benzene ring of dibasic carboxylic acid used, the electronegativity of fluorine atom is big, in esterification The conjugation effect of the fluorine atom in the reaction stage increases the acidity of the dicarboxylic acid, and at the same time increases the activity of the carboxyl group in the dicarboxylic acid, which speeds up the reaction rate, and the increase in the reaction rate is likely to cause side reactions. The follow-up polycondensation reaction has a greater impact, especially the generation of end-capped products of olefins and aldehydes, which restricts the increase in the molecular weight of the product; from the experimental results, if no inhibitor is added, the molecular weight of the synthesized polyester is low, which cannot meet the requirements. Spinning and film-forming requirements; the addition of inhibitors is used to control the speed of the esterification reaction stage, reducing side reactions, increasing the molecular weight of the product, and meeting the spinning requirements.

Usually, in the polyester esterification process, the hydrogen ion ionized by the dicarboxylic acid used is used as a catalyst for the esterification reaction to carry out a self-catalyzed reaction, and the esterification reaction is controlled by adjusting the temperature, pressure and discharge of small molecules. However, the premise of the esterification reaction is that the esterification reaction can only be carried out under a certain reaction temperature and pressure. When the temperature is too low or the pressure is not enough, the esterification reaction cannot proceed or the speed is extremely slow, thereby affecting the subsequent process. If the small molecules in the esterification reaction are not discharged in time, it is easy to cause unnecessary side reactions. During the synthesis process, due to the conjugation effect of fluorine, the fluorine atom increases the acidity of the dicarboxylic acid in the esterification reaction stage, and at the same time increases the activity of the carboxyl group in the dicarboxylic acid, which makes the reaction speed faster and the side reactions increase. Control, and then affect the growth of the molecular weight of the product, so the addition of inhibitors is adjusted by selecting the metal oxide used. The metal oxide can be dissociated in the following two ways:

Here M is a metal ion. If the electronegativity of M is quite large, it has a strong attraction to the electron pairs of oxygen ions, which can weaken the O—H bond and facilitate the reaction dissociation; on the contrary, if the electronegativity of M If the sex is small, then the base center will be formed. M—O—H is similar to amphoteric compounds. When alkaline substances exist, the reaction will proceed in the form of acid ionization; when acidic substances exist, the reaction will proceed in the form of basic ionization. From the reverse reactions of MO ^- and M ⁺ in the acid ionization mode and base ionization mode, it can be seen that M ⁺ acts as an acidic center, and its strength is only directly related to the electronegativity of the metal ion, while the O ion in MO ^- acts as a base The intensity of the center is related to the negative charge density on the oxygen, the greater the negative charge density, the greater the intensity. It can be seen that the negative charge density on oxygen ions is closely related to the electronegativity of metal ions, the smaller the electronegativity of metal ions, the greater the negative charge density. In this way, the acidity and alkalinity of metal oxides are related to the electronegativity of metal ions. The oxides with high electronegativity of metal ions are mainly acidic, while those with low electronegativity are alkaline.

Described polycondensation reaction:

Including the low vacuum stage of polycondensation reaction and the high vacuum stage of polycondensation reaction;

In the low-vacuum stage of the polycondensation reaction, catalysts and stabilizers are added to the esterification product, and the polycondensation reaction starts under negative pressure conditions. In this stage, the pressure is steadily pumped from normal pressure to below the absolute pressure of 500Pa, and the temperature is controlled at 260-270°C. , the reaction time is 40 to 60 minutes;

In the high vacuum stage of the polycondensation reaction, after the low vacuum stage of the polycondensation reaction, the vacuum is continued to reduce the reaction pressure to an absolute pressure of less than 100 Pa, the reaction temperature is controlled at 270-275°C, and the reaction time is 3-4 hours. The polycondensation reaction is based on the power of the stirring motor of the reactor or the reading of the online viscometer to judge the end point of the reaction.

As a preferred technical solution:

According to the above-mentioned preparation method of fluorine-containing PBT polyester POY fibers, the molar ratio of butanediol to tetrafluoroterephthalic acid is 1.4-2.0:1.

A kind of preparation method of fluorine-containing PBT polyester POY fiber as above, described catalyst is selected from tetrabutyl titanate, tetraisopropyl titanate, tetraethyl titanate, stannous acetate, dibutyltin diacetate In one of them, the amount of the catalyst is 0.01% to 0.05% of the weight of the tetrafluoroterephthalic acid.

A kind of preparation method of fluorine-containing PBT polyester POY fiber as described above, described stabilizer is selected from the one in triphenyl phosphate, trimethyl phosphate and trimethyl phosphite, and stabilizer consumption is described 0.01% to 0.05% by weight of tetrafluoroterephthalic acid.

According to the above-mentioned preparation method of fluorine-containing PBT polyester POY fibers, the added amount of the inhibitor is 0.01%-0.05% of the weight of the tetrafluoroterephthalic acid.

In the esterification reaction stage of the present invention, the end point of the reaction is determined by the amount of water distilled out actually produced in the esterification reaching more than 90% of the theoretical value. The theoretical value is the distilled amount of water obtained when the chemical reaction equation is completely reacted. Since the esterification reaction itself is a reversible reaction, and the raw materials will remain in the pipeline, and as the reaction progresses, the viscosity of the system will increase, making it difficult to discharge the water produced by the esterification reaction.

In the high vacuum stage of the polycondensation reaction of the present invention, the end point of the reaction is determined by the calculated value of the motor power of the reactor stirrer and the online viscosity reaching the set value. The set values of the motor power of the reactor agitator and the online viscosity calculation value of different devices are not necessarily the same, and the determination of the set values can be obtained by analyzing the polyester chips.

The monofilament fineness of the novel fluorine-containing PBT polyester POY fiber obtained by the invention is 0.5-3.0 dtex; the breaking strength is 2.0-3.5 cN/dtex; the breaking elongation is 90-130%. Due to the introduction of fluorine atoms, the superhydrophobic, oil-repellent and anti-fouling properties of polyester materials have been improved, and it has great prospects in the manufacture of waterproof clothing, dirt-resistant work clothes and work clothes in some special industries.

Beneficial effect:

1. The obtained new fluorine-containing PBT polyester POY fiber contains fluorine atoms. Due to the strong electronegativity of fluorine, the high C-F bond energy and the shielding effect on the carbon chain, the final copolyester POY fiber has a good Heat resistance, aging resistance, chemical corrosion resistance and low capacitance, low flammability, low refractive index and other properties, but also has some special electrical properties, such as low dielectric constant, high insulation and other advantages, expanding the scope of application.

2. The obtained novel fluorine-containing PBT polyester POY fiber has certain structural stability and processability.

3. The obtained novel fluorine-containing PBT polyester POY fiber has hydrophobic and anti-fouling properties by introducing fluorine atoms.

4. The new fluorine-containing PBT polyester POY fiber is modified by copolymerization, which fundamentally solves the problems of timeliness, durability and wear resistance of hydrophobic and antifouling polyester.

Detailed ways

The present invention will be further described below in combination with specific embodiments. It should be understood that these examples 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 teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

A fluorine-containing PBT polyester POY fiber, which is obtained by measuring, extruding, cooling, oiling and winding from a fluorine-containing PBT polyester melt; the hydrogen on the benzene ring of the fluorine-containing PBT polyester is replaced by fluorine The polytrimethylene terephthalate is polytetrafluorotrimethylene terephthalate, and its general structural formula is

Where n=70-200.

A kind of fluorine-containing PBT polyester POY fiber as described above, the monofilament fineness of the fluorine-containing PBT polyester POY fiber is 0.5～3.0dtex; the breaking strength is 2.0～3.5cN/dtex; the elongation at break is 90～ 130%.

Example 1

A preparation method of fluorine-containing PBT polyester is divided into two steps of esterification reaction and polycondensation reaction. The specific steps are:

Described esterification reaction:

1,3 propanediol and tetrafluoroterephthalic acid with a molar ratio of 1.3:1 are used as raw materials, and 0.01% manganese oxide by weight of tetrafluoroterephthalic acid is added at the same time, and the esterification reaction is carried out after making a uniform slurry; The reaction is carried out in a nitrogen atmosphere, the pressure is controlled at 0.3 MPa, the temperature is controlled at 260° C., and the esterification water distillation reaches 90% of the theoretical value, which is the end point of the esterification reaction.

Described polycondensation reaction:

Including low vacuum stage of polycondensation reaction and high vacuum stage of polycondensation reaction:

In the low-vacuum stage of the polycondensation reaction, 0.01% of the weight of tetrafluoroterephthalic acid as a catalyst tetrabutyl titanate-magnesium acetate and 0.01% of the weight of tetrafluoroterephthalic acid as a stabilizer triphosphate were added to the esterification product. The polycondensation reaction of phenyl ester starts under the condition of negative pressure. At this stage, the pressure is steadily pumped from normal pressure to an absolute pressure of less than 500Pa, the temperature is controlled at 265°C, and the reaction time is 50 minutes.

In the high vacuum stage of the polycondensation reaction, after the low vacuum stage of the polycondensation reaction, the vacuum is continued to reduce the reaction pressure to an absolute pressure of less than 100 Pa, the reaction temperature is controlled at 270° C., and the reaction time is 4 hours. The polycondensation reaction is based on the power of the stirring motor of the reactor or the reading of the online viscometer to judge the end point of the reaction.

Method for preparing POY fiber:

The POY fiber is obtained by directly extruding, cooling, oiling and winding the fluorine-containing PBT polyester melt; wherein, the extruding temperature is 265°C; the cooling is side blowing cooling, and the temperature is 25 ℃, relative humidity is 60%, and wind speed is 0.4m/s; Described oiling adopts the emulsion that contains the oil agent for fluorine-containing polyester POY fiber of 8wt%; The preparation of oil agent for fluorine-containing polyester POY fiber: its Components in parts by weight, take 60 parts of propylene glycol random polyether, heat to 60°C, mix 20 parts of polyethylene glycol monolaurate, 15 parts of potassium dodecyl phosphate and 5 parts of perfluorobutyl Ethyl acrylate was stirred and mixed evenly, then added to propylene glycol random polyether, and stirred for 1 hour to obtain POY oiling agent for fluorine-containing polyester fiber; the oiling rate of the oiling was 0.42%; the roll The winding speed is 3000m/min; the fluorine-containing PBT polyester POY fiber is finally obtained, the single filament fineness is 2.0dtex; the breaking strength is 3.0cN/dtex; the breaking elongation is 130%.

Example 2

A preparation method of fluorine-containing PBT polyester is divided into two steps of esterification reaction and polycondensation reaction. The specific steps are:

Described esterification reaction:

Using 1,3 propanediol and tetrafluoroterephthalic acid with a molar ratio of 1.4:1 as raw materials, and adding 0.02% magnesium oxide based on the weight of tetrafluoroterephthalic acid at the same time, the esterification reaction is carried out after making a uniform slurry; The reaction is carried out in a nitrogen atmosphere, the pressure is controlled at 0.3 MPa, the temperature is controlled at 260° C., and the esterification water distillation reaches 90% of the theoretical value, which is the end point of the esterification reaction.

Described polycondensation reaction:

Including low vacuum stage of polycondensation reaction and high vacuum stage of polycondensation reaction:

In the low-vacuum stage of the polycondensation reaction, 0.02% of the catalyst tetraisopropyl titanate-magnesium acetate and 0.02% of the tetrafluoroterephthalic acid weight of the tetrafluoroterephthalic acid were added to the esterification product. Stabilizer phosphoric acid Triphenyl ester, the polycondensation reaction starts under the condition of negative pressure, the pressure is steadily pumped from normal pressure to the absolute pressure less than 400Pa at this stage, the temperature is controlled at 265°C, and the reaction time is 50 minutes.

In the high vacuum stage of the polycondensation reaction, after the low vacuum stage of the polycondensation reaction, the vacuum is continued to reduce the reaction pressure to an absolute pressure of less than 100 Pa, the reaction temperature is controlled at 270° C., and the reaction time is 4 hours. The polycondensation reaction is based on the power of the stirring motor of the reactor or the reading of the online viscometer to judge the end point of the reaction.

Method for preparing POY fiber:

The POY fiber is obtained by directly extruding, cooling, oiling and winding the fluorine-containing PBT polyester melt; wherein, the extruding temperature is 285°C; the cooling is side blowing cooling, and the temperature is 20 DEG C, relative humidity is 70%, and wind speed is 0.8m/s; Described oiling adopts the emulsion that contains 9wt% the oil agent for fluorine-containing polyester POY fiber; The preparation of oil agent for fluorine-containing polyester POY fiber: its Components are calculated in parts by weight, take 50 parts of butanol random polyether, heat to 40 ° C, mix 32 parts of polyethylene glycol laurate diester, 15 parts of isomeric tridecyl alcohol polyoxyethylene ether phosphate potassium salt and 3 parts of perfluorohexyl ethyl acrylate were stirred and mixed evenly, then added to butanol random polyether, and stirred for 2 hours to obtain POY oil for fluorine-containing polyester fibers; the oiling rate of the oiling was 1.5%; the winding speed is 3100m/min; the fluorine-containing PBT polyester POY fiber is finally obtained, the single filament fineness is 2.0dtex; the breaking strength is 2.3cN/dtex; the breaking elongation is 120%.

Example 3

A preparation method of fluorine-containing PBT polyester is divided into two steps of esterification reaction and polycondensation reaction. The specific steps are:

Described esterification reaction:

1,3 propanediol and tetrafluoroterephthalic acid with a molar ratio of 1.6:1 are used as raw materials, and 0.05% silicon oxide of the weight of tetrafluoroterephthalic acid is added at the same time, and the esterification reaction is carried out after making a uniform slurry; The reaction is carried out in a nitrogen atmosphere, the pressure is controlled at 0.2 MPa, the temperature is controlled at 255° C., and the esterification water distillation reaches 90% of the theoretical value as the end point of the esterification reaction.

Described polycondensation reaction:

Including low vacuum stage of polycondensation reaction and high vacuum stage of polycondensation reaction:

In the low vacuum stage of the polycondensation reaction, 0.03% of the catalyst tetraethyl titanate-magnesium acetate and 0.03% of the tetrafluoroterephthalic acid weight of the tetrafluoroterephthalic acid were added to the esterification product. Methyl ester, polycondensation reaction starts under the condition of negative pressure. At this stage, the pressure is steadily pumped from normal pressure to an absolute pressure of less than 400Pa, the temperature is controlled at 260°C, and the reaction time is 45 minutes.

In the high vacuum stage of the polycondensation reaction, after the low vacuum stage of the polycondensation reaction, the vacuum was continued to reduce the reaction pressure to an absolute pressure of less than 80 Pa, the reaction temperature was controlled at 270° C., and the reaction time was 3.5 hours. The polycondensation reaction is based on the power of the stirring motor of the reactor or the reading of the online viscometer to judge the end point of the reaction.

Method for preparing POY fiber:

The POY fiber is obtained by directly extruding, cooling, oiling and winding the fluorine-containing PBT polyester melt; wherein, the extruding temperature is 275°C; the cooling is side blowing cooling, and the temperature is 22 ℃, relative humidity is 65%, and wind speed is 0.6m/s; Described oiling adopts the emulsion that contains 10wt% the oil agent for fluorine-containing polyester POY fiber; The preparation of oil agent for fluorine-containing polyester POY fiber: its Components in parts by weight, take 58 parts of lauric acid random polyether, heat to 60 ° C, add 30 parts of polyethylene glycol monooleate, 10 parts of potassium salt of tetradecyl alcohol phosphate and 2 parts of perfluoro The octyl ethyl acrylate is stirred and mixed evenly, then added to the propylene glycol random polyether, and stirred for 1 hour to obtain the POY oiling agent for fluorine-containing polyester fiber; the oiling rate of the oiling is 0.96%; The above-mentioned winding speed is 3200m/min; the fluorine-containing PBT polyester POY fiber is finally obtained, the single filament fineness is 1.5dtex; the breaking strength is 2.6cN/dtex; the breaking elongation is 110%.

Example 4

A preparation method of fluorine-containing PBT polyester is divided into two steps of esterification reaction and polycondensation reaction. The specific steps are:

Described esterification reaction:

Using 1,3 propanediol and tetrafluoroterephthalic acid with a molar ratio of 1.8:1 as raw materials, and adding 0.04% zinc oxide based on the weight of tetrafluoroterephthalic acid at the same time, the esterification reaction is carried out after making a uniform slurry; The reaction is carried out in a nitrogen atmosphere, the pressure is controlled at 0.2 MPa, the temperature is controlled at 250° C., and the esterification water distillation reaches 90% of the theoretical value as the end point of the esterification reaction.

Described polycondensation reaction:

Including low vacuum stage of polycondensation reaction and high vacuum stage of polycondensation reaction:

In the low vacuum stage of the polycondensation reaction, add 0.04% of the catalyst stannous acetate of tetrafluoroterephthalic acid weight and 0.04% of the stabilizer trimethyl phosphate of tetrafluoroterephthalic acid weight in the esterification product, The polycondensation reaction starts under the condition of low pressure, and the pressure at this stage is steadily pumped from normal pressure to an absolute pressure of less than 300Pa, the temperature is controlled at 270°C, and the reaction time is 40 minutes.

In the high vacuum stage of the polycondensation reaction, after the low vacuum stage of the polycondensation reaction, the vacuum was continued to reduce the reaction pressure to an absolute pressure of less than 60 Pa, the reaction temperature was controlled at 275° C., and the reaction time was 3 hours. The polycondensation reaction is based on the power of the stirring motor of the reactor or the reading of the online viscometer to judge the end point of the reaction.

Method for preparing POY fiber:

The POY fiber is obtained by directly extruding, cooling, oiling and winding the fluorine-containing PBT polyester melt; wherein, the extruding temperature is 265°C; the cooling is side blowing cooling, and the temperature is 25 ℃, relative humidity is 60%, and wind speed is 0.4m/s; Described oiling adopts the emulsion that contains the oil agent for fluorine-containing polyester POY fiber of 8wt%; The preparation of oil agent for fluorine-containing polyester POY fiber: its The components are calculated in parts by weight. Take 50 parts of lauryl alcohol random polyether, heat it to 50°C, add 32 parts of polyethylene glycol diester oleate, 13 parts of potassium dodecyl phosphate and 5 parts of perfluorinated Butyl ethyl methacrylate is stirred and mixed evenly, then added to propylene glycol random polyether, and stirred for 1 hour to obtain POY oil for fluorine-containing polyester fiber; the oiling rate of the oiling is 1.5% The winding speed is 3300m/min; the fluorine-containing PBT polyester POY fiber is finally obtained, the single filament fineness is 0.5dtex; the breaking strength is 3.2cN/dtex; the elongation at break is 100%.

Example 5

A preparation method of fluorine-containing PBT polyester is divided into two steps of esterification reaction and polycondensation reaction. The specific steps are:

Described esterification reaction:

Using 1,3 propanediol and tetrafluoroterephthalic acid with a molar ratio of 2.0:1 as raw materials, and adding 0.03% calcium oxide based on the weight of tetrafluoroterephthalic acid at the same time, the esterification reaction is carried out after making a uniform slurry; The reaction is carried out in a nitrogen atmosphere, the pressure is controlled at normal pressure, the temperature is controlled at 255° C., and the esterification water distillation reaches 90% of the theoretical value as the end point of the esterification reaction.

Described polycondensation reaction:

Including low vacuum stage of polycondensation reaction and high vacuum stage of polycondensation reaction:

In the low-vacuum stage of the polycondensation reaction, add 0.05% of the catalyst dibutyltin diacetate and 0.05% of the tetrafluoroterephthalic acid weight in the esterification product. Stabilizer trimethyl phosphite, The polycondensation reaction starts under the condition of negative pressure, and the pressure in this stage is steadily pumped from normal pressure to an absolute pressure of less than 300Pa, the temperature is controlled at 265°C, and the reaction time is 30 minutes.

In the high vacuum stage of the polycondensation reaction, after the low vacuum stage of the polycondensation reaction, the vacuum is continued to reduce the reaction pressure to an absolute pressure of less than 50 Pa, the reaction temperature is controlled at 275° C., and the reaction time is 3 hours. The polycondensation reaction is based on the power of the stirring motor of the reactor or the reading of the online viscometer to judge the end point of the reaction.

Method for preparing POY fiber:

The POY fiber is obtained by directly extruding, cooling, oiling and winding the fluorine-containing PBT polyester melt; wherein, the extruding temperature is 285°C; the cooling is side blowing cooling, and the temperature is 20 ℃, relative humidity is 70%, and wind speed is 0.8m/s; Described oiling adopts the emulsion that contains the oil agent for fluorine-containing polyester POY fiber of 8wt%; The preparation of oil agent for fluorine-containing polyester POY fiber: its Components in parts by weight, take 55 parts of isomeric tridecanol random polyether, heat to 55 ° C, mix 25 parts of polyethylene glycol diester laurate, 15 parts of potassium lauryl phosphate and 5 parts Perfluorohexyl ethyl methacrylate was stirred and mixed evenly, then added to propylene glycol random polyether, and stirred for 2 hours to obtain POY oil for fluorine-containing polyester fibers; the oiling rate of the oiling was 0.42 %; the winding speed is 3500m/min; the fluorine-containing PBT polyester POY fiber is finally obtained, the single filament fineness is 1.0dtex; the breaking strength is 3.5cN/dtex; the elongation at break is 90%.

Example 6

A preparation method of fluorine-containing PBT polyester is divided into two steps of esterification reaction and polycondensation reaction. The specific steps are:

Described esterification reaction:

Using 1,3 propanediol and tetrafluoroterephthalic acid with a molar ratio of 1.3:1 as raw materials, and adding 0.05% magnesium oxide based on the weight of tetrafluoroterephthalic acid at the same time, the esterification reaction is carried out after making a uniform slurry; The reaction is carried out in a nitrogen atmosphere, the pressure is controlled at 0.3 MPa, the temperature is controlled at 260° C., and the esterification water distillation reaches 90% of the theoretical value, which is the end point of the esterification reaction.

Described polycondensation reaction:

Including low vacuum stage of polycondensation reaction and high vacuum stage of polycondensation reaction:

In the low-vacuum stage of the polycondensation reaction, 0.01% of the weight of tetrafluoroterephthalic acid as a catalyst tetrabutyl titanate-magnesium acetate and 0.01% of the weight of tetrafluoroterephthalic acid as a stabilizer triphosphate were added to the esterification product. The polycondensation reaction of phenyl ester starts under the condition of negative pressure. At this stage, the pressure is steadily pumped from normal pressure to an absolute pressure of less than 500Pa, the temperature is controlled at 265°C, and the reaction time is 50 minutes.

In the high vacuum stage of the polycondensation reaction, after the low vacuum stage of the polycondensation reaction, the vacuum is continued to reduce the reaction pressure to an absolute pressure of less than 100 Pa, the reaction temperature is controlled at 270° C., and the reaction time is 4 hours. The polycondensation reaction is based on the power of the stirring motor of the reactor or the reading of the online viscometer to judge the end point of the reaction. When the viscosity of the polymer reaches the desired value, the material is discharged, and after casting, cooling and pelletizing, the fluorine-containing PBT polyester chips are obtained.

Method for preparing POY fiber:

The POY fiber is obtained from the fluorine-containing PBT polyester chips through screw melt extrusion, cooling, oiling and winding; wherein, the extruding temperature is 265°C; the cooling is ring air cooling, the temperature The temperature is 25°C, the relative humidity is 60%, and the wind speed is 0.4m/s; the oiling adopts the emulsion containing 8wt% fluorine-containing polyester POY fiber oil; the preparation of fluorine-containing polyester POY fiber oil: Its components are calculated in parts by weight. Take 60 parts of propylene glycol random polyether, heat it to 45°C, add 20 parts of polyethylene glycol monooleate, 15 parts of potassium dodecyl phosphate and 5 parts of perfluorooctyl Ethyl methacrylate was stirred and mixed evenly, then added to propylene glycol random polyether, and stirred for 1 hour to obtain POY oil for fluorine-containing polyester fibers; the oiling rate of the oiling was 0.42%; The winding speed is 3000m/min; the fluorine-containing PBT polyester POY fiber is finally obtained, the single filament fineness is 3.0dtex; the breaking strength is 2.0cN/dtex; the breaking elongation is 130%.

Example 7

A preparation method of fluorine-containing PBT polyester is divided into two steps of esterification reaction and polycondensation reaction. The specific steps are:

Described esterification reaction:

Using 1,3-propanediol and tetrafluoroterephthalic acid with a molar ratio of 1.4:1 as raw materials, and adding 0.02% silicon oxide by weight of tetrafluoroterephthalic acid at the same time, the esterification reaction is carried out after making a uniform slurry; The reaction is carried out in a nitrogen atmosphere, the pressure is controlled at 0.3 MPa, the temperature is controlled at 260° C., and the esterification water distillation reaches 90% of the theoretical value, which is the end point of the esterification reaction.

Described polycondensation reaction:

Including low vacuum stage of polycondensation reaction and high vacuum stage of polycondensation reaction:

In the low-vacuum stage of the polycondensation reaction, 0.02% of the catalyst tetraisopropyl titanate-magnesium acetate and 0.02% of the tetrafluoroterephthalic acid weight of the tetrafluoroterephthalic acid were added to the esterification product. Stabilizer phosphoric acid Triphenyl ester, the polycondensation reaction starts under the condition of negative pressure, the pressure is steadily pumped from normal pressure to the absolute pressure less than 400Pa at this stage, the temperature is controlled at 265°C, and the reaction time is 50 minutes.

In the high vacuum stage of the polycondensation reaction, after the low vacuum stage of the polycondensation reaction, the vacuum is continued to reduce the reaction pressure to an absolute pressure of less than 100 Pa, the reaction temperature is controlled at 270° C., and the reaction time is 4 hours. The polycondensation reaction is based on the power of the stirring motor of the reactor or the reading of the online viscometer to judge the end point of the reaction. When the viscosity of the polymer reaches the desired value, the material is discharged, and after casting, cooling and pelletizing, the fluorine-containing PBT polyester chips are obtained.

Method for preparing POY fiber:

The POY fiber is obtained from the fluorine-containing PBT polyester chips through screw melt extrusion, cooling, oiling and winding; wherein, the extruding temperature is 285°C; the cooling is ring air cooling, the temperature The temperature is 20°C, the relative humidity is 70%, and the wind speed is 0.8m/s; the oiling adopts an emulsion containing 8wt% oil for fluorine-containing polyester POY fibers; the preparation of oil for fluorine-containing polyester POY fibers: Its components are calculated in parts by weight. Take 50 parts of butanol random polyether, heat it to 40 ° C, mix 32 parts of polyethylene glycol laurate diester, 15 parts of isomeric tridecyl polyoxyethylene ether phosphate potassium salt Stir and mix with 3 parts of perfluorohexyl ethyl acrylate, then add it into butanol random polyether, and stir for 2 hours to obtain POY oiling agent for fluorine-containing polyester fibers; the oiling rate of the oiling 1.5%; the winding speed is 3100m/min; finally obtained fluorine-containing PBT polyester POY fiber, single filament fineness is 2.0dtex; breaking strength is 2.3cN/dtex; breaking elongation is 120%.

Example 8

A preparation method of fluorine-containing PBT polyester is divided into two steps of esterification reaction and polycondensation reaction. The specific steps are:

Described esterification reaction:

1,3 propanediol and tetrafluoroterephthalic acid with a molar ratio of 1.6:1 are used as raw materials, and 0.05% calcium oxide based on the weight of tetrafluoroterephthalic acid is added at the same time, and the esterification reaction is carried out after making a uniform slurry; The reaction is carried out in a nitrogen atmosphere, the pressure is controlled at 0.2 MPa, the temperature is controlled at 255° C., and the esterification water distillation reaches 90% of the theoretical value as the end point of the esterification reaction.

Described polycondensation reaction:

Including low vacuum stage of polycondensation reaction and high vacuum stage of polycondensation reaction:

In the low vacuum stage of the polycondensation reaction, 0.03% of the catalyst tetraethyl titanate-magnesium acetate and 0.03% of the tetrafluoroterephthalic acid weight of the tetrafluoroterephthalic acid were added to the esterification product. Methyl ester, the polycondensation reaction starts under the condition of negative pressure. At this stage, the pressure is steadily pumped from normal pressure to an absolute pressure of less than 400Pa, the temperature is controlled at 260°C, and the reaction time is 45 minutes.

In the high vacuum stage of the polycondensation reaction, after the low vacuum stage of the polycondensation reaction, the vacuum was continued to reduce the reaction pressure to an absolute pressure of less than 80 Pa, the reaction temperature was controlled at 270° C., and the reaction time was 3.5 hours. The polycondensation reaction is based on the power of the stirring motor of the reactor or the reading of the online viscometer to judge the end point of the reaction. When the viscosity of the polymer reaches the desired value, the material is discharged, and after casting, cooling and pelletizing, the fluorine-containing PBT polyester chips are obtained.

Method for preparing POY fiber:

The POY fiber is obtained from the fluorine-containing PBT polyester chips through screw melt extrusion, cooling, oiling and winding; wherein, the extruding temperature is 275°C; the cooling is ring air cooling, the temperature The temperature is 22°C, the relative humidity is 65%, and the wind speed is 0.6m/s; the oiling adopts the emulsion containing 8wt% fluorine-containing polyester POY fiber oil; the preparation of fluorine-containing polyester POY fiber oil: Its components are calculated in parts by weight. Take 60 parts of propylene glycol random polyether, heat it to 60 ° C, add 20 parts of polyethylene glycol monolaurate, 15 parts of potassium lauryl phosphate and 5 parts of perfluorobutyl Ethyl acrylate was stirred and mixed evenly, then added to propylene glycol random polyether, and stirred for 1 hour to obtain POY oil for fluorine-containing polyester fibers; the oiling rate of the oiling was 0.96%; the The winding speed is 3200m/min; the fluorine-containing PBT polyester POY fiber is finally obtained, the single filament fineness is 1.5dtex; the breaking strength is 2.6cN/dtex; the breaking elongation is 110%.

Example 9

A preparation method of fluorine-containing PBT polyester is divided into two steps of esterification reaction and polycondensation reaction. The specific steps are:

Described esterification reaction:

1,3 propanediol and tetrafluoroterephthalic acid with a molar ratio of 1.8:1 are used as raw materials, and 0.01% zinc oxide based on the weight of tetrafluoroterephthalic acid is added at the same time, and the esterification reaction is carried out after making a uniform slurry; The reaction is carried out in a nitrogen atmosphere, the pressure is controlled at 0.2 MPa, the temperature is controlled at 250° C., and the esterification water distillation reaches 90% of the theoretical value, which is the end point of the esterification reaction.

Described polycondensation reaction:

Including low vacuum stage of polycondensation reaction and high vacuum stage of polycondensation reaction:

In the low vacuum stage of the polycondensation reaction, add 0.04% of the catalyst stannous acetate of tetrafluoroterephthalic acid weight and 0.04% of the stabilizer trimethyl phosphate of tetrafluoroterephthalic acid weight in the esterification product, The polycondensation reaction starts under the condition of low pressure, and the pressure at this stage is steadily pumped from normal pressure to an absolute pressure of less than 300Pa, the temperature is controlled at 270°C, and the reaction time is 40 minutes.

In the high vacuum stage of the polycondensation reaction, after the low vacuum stage of the polycondensation reaction, the vacuum is continued to reduce the reaction pressure to an absolute pressure of less than 60 Pa, the reaction temperature is controlled at 275° C., and the reaction time is 3 hours. The polycondensation reaction is based on the power of the stirring motor of the reactor or the reading of the online viscometer to judge the end point of the reaction. When the viscosity of the polymer reaches the desired value, the material is discharged, and after casting, cooling and pelletizing, the fluorine-containing PBT polyester chips are obtained.

Method for preparing POY fiber:

The POY fiber is obtained from the fluorine-containing PBT polyester chips through screw melt extrusion, cooling, oiling and winding; wherein, the extruding temperature is 265°C; the cooling is ring air cooling, the temperature The temperature is 25°C, the relative humidity is 60%, and the wind speed is 0.4m/s; the oiling adopts the emulsion containing 8wt% fluorine-containing polyester POY fiber oil; the preparation of fluorine-containing polyester POY fiber oil: Its components are calculated in parts by weight. Take 50 parts of lauryl alcohol random polyether, heat it to 50 ° C, mix 32 parts of polyethylene glycol diester, 13 parts of potassium dodecyl phosphate and 5 parts of all Fluorobutyl ethyl methacrylate was stirred and mixed evenly, then added to propylene glycol random polyether, and stirred for 1 hour to obtain POY oil for fluorine-containing polyester fiber; the oiling rate of the oiling was 1.5 %; the winding speed is 3300m/min; the fluorine-containing PBT polyester POY fiber is finally obtained, the single filament fineness is 0.5dtex; the breaking strength is 3.2cN/dtex; the elongation at break is 100%.

Example 10

A preparation method of fluorine-containing PBT polyester is divided into two steps of esterification reaction and polycondensation reaction. The specific steps are:

Described esterification reaction:

1,3 propanediol and tetrafluoroterephthalic acid with a molar ratio of 2.0:1 are used as raw materials, and 0.03% manganese oxide of the weight of tetrafluoroterephthalic acid is added at the same time, and the esterification reaction is carried out after making a uniform slurry; The reaction is carried out in a nitrogen atmosphere, the pressure is controlled at normal pressure, the temperature is controlled at 255° C., and the esterification water distillation reaches 90% of the theoretical value as the end point of the esterification reaction.

Described polycondensation reaction:

Including low vacuum stage of polycondensation reaction and high vacuum stage of polycondensation reaction:

In the low-vacuum stage of the polycondensation reaction, add 0.05% of the catalyst dibutyltin diacetate and 0.05% of the tetrafluoroterephthalic acid weight in the esterification product. Stabilizer trimethyl phosphite, The polycondensation reaction starts under the condition of negative pressure, and the pressure in this stage is steadily pumped from normal pressure to an absolute pressure of less than 300Pa, the temperature is controlled at 265°C, and the reaction time is 30 minutes.

In the high vacuum stage of the polycondensation reaction, after the low vacuum stage of the polycondensation reaction, the vacuum is continued to reduce the reaction pressure to an absolute pressure of less than 50 Pa, the reaction temperature is controlled at 275° C., and the reaction time is 3 hours. The polycondensation reaction is based on the power of the stirring motor of the reactor or the reading of the online viscometer to judge the end point of the reaction. When the viscosity of the polymer reaches the desired value, the material is discharged, and after casting, cooling and pelletizing, the fluorine-containing PBT polyester chips are obtained.

Method for preparing POY fiber:

The POY fiber is obtained from the fluorine-containing PBT polyester chips through screw melt extrusion, cooling, oiling and winding; wherein, the extruding temperature is 285°C; the cooling is ring air cooling, the temperature The temperature is 20°C, the relative humidity is 70%, and the wind speed is 0.8m/s; the oiling adopts an emulsion containing 8wt% oil for fluorine-containing polyester POY fibers; the preparation of oil for fluorine-containing polyester POY fibers: Its components are calculated in parts by weight. Take 60 parts of propylene glycol random polyether, heat it to 45°C, add 20 parts of polyethylene glycol monooleate, 15 parts of potassium dodecyl phosphate and 5 parts of perfluorooctyl Ethyl methacrylate was stirred and mixed evenly, then added to propylene glycol random polyether, and stirred for 1 hour to obtain POY oil for fluorine-containing polyester fibers; the oiling rate of the oiling was 0.42%; The winding speed is 3500m/min; the fluorine-containing PBT polyester POY fiber is finally obtained, the single filament fineness is 1.0dtex; the breaking strength is 3.5cN/dtex; the breaking elongation is 90%.

Claims (8)

1. A preparation method of fluorine-containing PBT polyester POY fiber, characterized in that: said fluorine-containing PBT polyester POY fiber is measured, extruded, cooled, oiled and wound by fluorine-containing PBT polyester melt Prepared; the polybutylene terephthalate in which the hydrogen on the benzene ring of the fluorine-containing PBT polyester is substituted by fluorine is polytetrafluorobutylene terephthalate, and its general structural formula is Among them, n=70～150; The monofilament fineness of the fluorine-containing PBT polyester POY fiber is 0.5-3.0 dtex; the breaking strength is 2.0-3.5 cN/dtex; the elongation at break is 90-130%; The fluorine-containing PBT polyester POY fiber is obtained from the fluorine-containing PBT polyester melt through the steps of metering, extrusion, cooling, oiling and winding, wherein: The extrusion temperature is 265-285°C; The wind temperature of described cooling is 20～25 ℃; The oiling rate of the oiling is 0.42～1.5%; The winding speed is 3000-3500m/min; The oiling agent for oiling is an oiling agent for fluorine-containing polyester POY fibers, and its components are by weight: Random polyether, 50-60 parts; Polyethylene glycol fatty acid ester, 20-32 parts; Phosphate potassium salt, 10-15 parts; Perfluoroalkyl acrylate, 2 to 5 parts; Preparation method of oil agent: Heat the random polyether to 40-60°C, stir and mix the polyethylene glycol fatty acid ester, phosphate potassium salt and perfluoroalkyl acrylate evenly, then add it to the random polyether, stir for 1-2 Hours, the oil for fluorine-containing polyester POY fibers is obtained, and when the oil is used, water is added to form an emulsion with a solid content of 8 to 10 wt%. The fluorine-containing PBT polyester melt refers to the melted fluorine-containing PBT polyester, and the preparation method of the fluorine-containing PBT polyester is divided into two steps of esterification reaction and polycondensation reaction; the specific steps are: Described esterification reaction: Tetrafluoroterephthalic acid and 1,4-butanediol are used as raw materials, and inhibitors are added to prepare a uniform slurry for esterification reaction to obtain esterification products; the esterification reaction is carried out in a nitrogen atmosphere, and the pressure is controlled at less than The absolute pressure is 1KPa, the temperature is 160-220°C, the time is 2-3 hours, and the distilled amount of esterification water reaches more than 90% of the theoretical value, which is the end point of the esterification reaction; The inhibitor is one of magnesium oxide, silicon oxide, calcium oxide, zinc oxide and manganese oxide; Described polycondensation reaction: Including low vacuum stage of polycondensation reaction and high vacuum stage of polycondensation reaction: In the low-vacuum stage of the polycondensation reaction, catalysts and stabilizers are added to the esterification product, and the polycondensation reaction starts under negative pressure conditions. In this stage, the pressure is steadily pumped from normal pressure to below the absolute pressure of 500Pa, and the temperature is controlled at 260-270°C. , the reaction time is 40 to 60 minutes; In the high vacuum stage of the polycondensation reaction, after the low vacuum stage of the polycondensation reaction, the vacuum is continued to reduce the reaction pressure to an absolute pressure of less than 100 Pa, the reaction temperature is controlled at 270-275°C, and the reaction time is 3-4 hours. 2. The preparation method of a kind of fluorine-containing PBT polyester POY fiber according to claim 1, characterized in that, the cooling is side blowing or ring blowing cooling, the temperature is 20° C. to 25° C., and the relative humidity is 65° C. %±5%, the wind speed is 0.4～0.8m/s. 3. the preparation method of a kind of fluorine-containing PBT polyester POY fiber according to claim 1 is characterized in that, the mol ratio of described 1,4-butanediol and tetrafluoroterephthalic acid is 1.4～2.0 :1. 4. the preparation method of a kind of fluorine-containing PBT polyester POY fiber according to claim 1 is characterized in that, described catalyst is selected from tetrabutyl titanate, tetraisopropyl titanate, tetraethyl titanate , stannous acetate, dibutyltin diacetate, the amount of catalyst used is 0.01% to 0.05% of the weight of the tetrafluoroterephthalic acid. 5. the preparation method of a kind of fluorine-containing PBT polyester POY fiber according to claim 1 is characterized in that, described stabilizing agent is selected from triphenyl phosphate, trimethyl phosphate and trimethyl phosphite One, the dosage of the stabilizer is 0.01%-0.05% of the weight of the tetrafluoroterephthalic acid. 6 . A method for preparing fluorine-containing PBT polyester POY fibers according to claim 1 , wherein the addition of the inhibitor is 0.01% to 0.05% of the weight of the tetrafluoroterephthalic acid. 7. the preparation method of a kind of fluorine-containing PBT polyester POY fiber according to claim 1, is characterized in that, described fluorine-containing PBT polyester melt is to obtain directly by polymerization or by fluorine-containing PBT polyester chips through screw obtained by melting. 8. the preparation method of a kind of fluorine-containing PBT polyester POY fiber according to claim 1 is characterized in that, described random polyether is propylene glycol random polyether, butanol random polyether, lauric acid free One of regular polyether, lauryl alcohol random polyether and isomeric tridecyl alcohol random polyether; the polyethylene glycol fatty acid ester is polyethylene glycol laurate monoester, polyethylene glycol One of lauric acid diester, polyethylene glycol oleic acid monoester and polyethylene glycol oleic acid diester; the potassium phosphate is lauryl phosphate potassium salt, isomeric tridecyl alcohol polyester One of oxyethylene ether phosphate potassium salt and tetradecyl phosphate potassium salt; the perfluoroalkyl acrylate is perfluorobutyl ethyl acrylate, perfluorohexyl ethyl acrylate, perfluorohexyl ethyl acrylate, One of fluorooctyl ethyl acrylate, perfluorobutyl ethyl methacrylate, perfluorohexyl ethyl methacrylate and perfluoro octyl ethyl methacrylate.