Modified polyesters and methods for making the same

Abstract

The present application relates to polyester material, disclose a kind of modified polyester and its preparation method and application.The modified polyester contains attapulgite, structural unit a and structural unit b, the structural unit a contains naphthalene ring structure and C1-C4 alkylene oxy group connected on the naphthalene ring structure, the C1-C4 alkylene oxy group is connected with the naphthalene ring structure by C-C bond, the structure of the structural unit b is as shown in formula (I).The modified polyester has higher T mc Temperature and lower T c Temperature, facilitate the rapid drying of polyester, and can effectively improve the crystallization rate of polyester.

Description

Technical Field

[0001] This invention relates to polyester materials, and more specifically to a modified polyester and its preparation method. Background Technology

[0002] Microfiber is a high-end variety of polyester fiber, characterized by its extremely low linear density and high specific surface area. Fabrics made from microfiber possess a soft, elegant luster and unique advantages such as suppleness, drape, and breathability. Microfiber has a wide range of applications, including the production of artificial leather, cleanroom cloths, high-grade air filters, and dust masks, resulting in products with very high added value. The island-island composite spinning method is the main method for producing microfiber, yielding single filaments with a fineness below 0.01 dtex. Island-island composite spinning involves blending water-soluble polyester (COPET) and conventional polyester (PET) in a specific ratio, resulting in fibers with an island-like structure. The aqueous polyester acts as the dispersed phase, or "sea phase," distributed on the surface and in the middle of the fiber. After the fabric woven from this fiber undergoes alkali treatment to dissolve the "sea phase" aqueous polyester, high-grade microfiber fabrics such as imitation suede are obtained.

[0003] Water-soluble polyesters typically use terephthalic acid and ethylene glycol as the main components, with sodium bis(hydroxyethyl) isophthalate-5-sulfonate (SIPE) as the third monomer. Other components such as polyethylene glycol (PEG), isophthalate, and adipic acid can also be added. The purpose of adding sodium bis(hydroxyethyl) isophthalate-5-sulfonate is to give the synthesized copolyester water-soluble properties. However, due to the meta-benzene ring structure of the third monomer SIPE and the steric hindrance effect of the sulfonic acid groups, the internal gyration activation energy of the macromolecular chain is increased. Simultaneously, the sulfonic acid groups increase the entanglement points of the molecular chain, reducing the mobility of the macromolecular chain and worsening its crystallinity. Water-soluble polyesters are particularly prone to sticking together during drying, requiring special equipment for drying chips, which is inconvenient for users. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of difficult polyester drying and slow crystallization in existing technologies, and to provide a modified polyester, its preparation method, and its application. This modified polyester has a high melting and crystallization temperature (T). mc and lower cold crystallization temperature (T) c This facilitates rapid drying of polyester and effectively improves the crystallization rate of polyester.

[0005] To achieve the above objectives, a first aspect of the present invention provides a modified polyester comprising attapulgite, structural unit a, and structural unit b. Structural unit a comprises a naphthalene ring structure and a C1-C4 alkylene group connected to the naphthalene ring structure. The C1-C4 alkylene group is connected to the naphthalene ring structure via a C-C bond. The structure of structural unit b is shown in formula (I).

[0006]

[0007] A second aspect of the present invention provides a method for preparing a modified polyester, comprising the following steps:

[0008] S1. Under esterification conditions, a dicarboxylic acid monomer, a diol monomer, a catalyst, and an auxiliary agent are subjected to contact reaction I to obtain the reactants;

[0009] The additive contains attapulgite and a diol having the structure shown in structural unit a, wherein structural unit a contains a naphthalene ring structure and a C1-C4 alkylene group attached to the naphthalene ring structure, and the C1-C4 alkylene group is attached to the naphthalene ring structure via a C-C bond.

[0010] S2. Under polymerization conditions, the reactants and a dihydroxy ester sulfonate containing the structure shown in formula (I) are subjected to a contact reaction II.

[0011]

[0012] Through the above technical solution, the modified polyester provided by the present invention simultaneously contains attapulgite, structural unit a, and structural unit b. Structural unit a is defined as containing a naphthalene ring structure and C1-C4 alkylene groups connected to the naphthalene ring structure. The C1-C4 alkylene groups are connected to the naphthalene ring structure via C-C bonds. The structure of structural unit b is defined as shown in formula (I). Through the interaction between the above structural units and attapulgite, the polyester exhibits a high melting crystallization temperature and a low cold crystallization temperature, facilitating rapid drying and effectively improving the crystallization rate of the polyester. Simultaneously, the polyester possesses good water solubility. Furthermore, the polyester provided by the present invention has a high alkali loss, resulting in a lighter weight after alkali treatment, thus more closely resembling the texture of silk. Clothing made from this polyester offers higher comfort. Detailed Implementation

[0013] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0014] As previously stated, a first aspect of the present invention provides a modified polyester comprising attapulgite, structural unit a, and structural unit b. Structural unit a comprises a naphthalene ring structure and C1-C4 alkylene groups attached to the naphthalene ring structure. The C1-C4 alkylene groups are connected to the naphthalene ring structure via C-C bonds. The structure of structural unit b is shown in formula (I).

[0015]

[0016] According to the present invention, in the improved polyester, the attapulgite content is quantitatively tested by the ash method, and the content of structural unit a and structural unit b is tested by gas chromatography.

[0017] According to the present invention, the C1-C4 alkylene oxides may be methylene oxide (methoxy), ethylene oxide (ethoxy), n-propylene oxide (propoxy), isopropylene oxide (isopropoxy), n-butylene oxide (butoxy), isobutylene oxide (isobutoxy), or tert-butylene oxide (tert-butoxy), with ethylene oxide (ethoxy) being preferred.

[0018] During their research, the inventors discovered that the modified polyester simultaneously contains attapulgite, structural unit a, and structural unit b. Structural unit a is defined as containing a naphthalene ring structure and C1-C4 alkylene groups connected to the naphthalene ring structure via C-C bonds. Structural unit b is defined as shown in formula (I). Through the interaction between these structural units and attapulgite, the polyester exhibits a high melting crystallization temperature and a low cold crystallization temperature, facilitating rapid drying and effectively increasing the crystallization rate. Simultaneously, this polyester possesses good water solubility. This water-soluble polyester has promising applications in coatings and other fields. Furthermore, the fibers prepared from the polyester provided by this invention exhibit high alkali loss and, after alkali treatment, have a lighter weight, thus more closely resembling the texture of silk. Clothing made from this polyester offers higher comfort.

[0019] Preferably, the naphthalene ring structure has an even number of C1-C4 alkylene groups, and these even number of C1-C4 alkylene groups are symmetrically arranged on the naphthalene ring structure. By limiting the number of C1-C4 alkylene groups on structural unit a to an even number and symmetrically arranging them on the naphthalene ring structure, the T of the polyester can be further improved. mc Temperature and reducing the T of polyester c The alkali reduction of polyester is increased simultaneously with the increase in temperature.

[0020] According to the present invention, the symmetrical arrangement here can be symmetrical about the C-C bond connecting the two rings in the naphthalene ring structure as the axis of symmetry, or it can be symmetrical about a straight line perpendicular to the C-C bond connecting the two rings in the naphthalene ring structure.

[0021] From T, which can further improve polyester mc Temperature and reducing the T of polyester c Taking into account temperature and increasing the alkali reduction of polyester, more preferably, the structure of structural unit a is as shown in formula (II).

[0022]

[0023] Among them, R I and R III It is a C1-C4 alkylene group, R II and R IV Each is independently C1-C4 alkyl or hydrogen, R I and R III The values ​​are symmetrically set, where m, n, and x are all natural numbers, and m+n≤4, x+n≤4, and n≥1.

[0024] According to the present invention, the C1-C4 alkylene groups can be methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, or tert-butylene; the C1-C4 alkyl groups can be methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl. m and x can each independently be 0, 1, 2, or 3, and n can be 1, 2, 3, or 4, as long as m+n≤4 and x+n≤4. m and x can be the same or different.

[0025] Preferably, R II and R IV It is a C1-C2 alkyl or hydrogen, m = x, and R II and R IV Symmetrical setting, R I and R III It is a C1-C2 alkylene group. R I R II R III and R IV By controlling the T of polyester within the above range, the T can be further improved. mc Temperature and reducing the T of polyester c Temperature increases further improve the alkali reduction of polyester. This, in turn, increases the T... mc Temperature and reducing the T of polyester c Taking temperature and increasing the alkali reduction of polyester into consideration, further preferably, R I and R III It is a methylene group. More preferably, n is 1, m is 3, x is 3, and R is... II and RIV It is hydrogen.

[0026] Preferably, in the modified polyester, the content of structural unit a is 0.01-0.06 wt%, the content of attapulgite is 0.3-3.2 wt%, and the content of structural unit b is 13.2-18.5 wt%. The modified polyester under the above conditions has a higher Tg. mc Temperature and lower T c While maintaining a higher temperature, it also exhibits greater alkali reduction. Preferably, the content of structural unit a is 0.01-0.05 wt%, the content of attapulgite is 0.3-2 wt%, and the content of structural unit b is 13.5-17.5 wt%. This allows for further improvement of the T... mc Temperature and reducing the T of polyester c Taking into account temperature and the alkali reduction of the polyester, more preferably, the mass ratio of structural unit a, the attapulgite clay, and the structural unit b is 1:5-260:250-1500. More preferably, the mass ratio of structural unit a, the attapulgite clay, and the structural unit b is 1:6-55:300-500.

[0027] According to the present invention, the contents of the above-mentioned structural unit a and structural unit b can be tested by gas chromatography, and the contents of attapulgite can be tested by ash content method.

[0028] Preferably, the modified polyester further contains the structural unit c shown in formula (III).

[0029]

[0030] Among them, R A It is a C2-C4 alkylene group, and n is a natural number of 30-45. The polyester also contains structural unit c as shown in formula (III), and through the interaction between structural units a, b, and attapulgite, the T of the polyester can be further improved. mc Temperature and reducing the T of polyester c Increasing temperature simultaneously increases the alkali reduction of polyester. This allows for further improvement in the T... mc Temperature and reducing the T of polyester c Taking into account temperature and the alkali reduction of the polyester, more preferably, n is a natural number of 35-45. More preferably, in the modified polyester, the content of the structural unit c is 9.5-13 wt%.

[0031] Preferably, the modified polyester further comprises structural unit d as shown in formula (IV) and structural unit e as shown in formula (V);

[0032]

[0033] -OR B -O- Equation (V),

[0034] Where R1 is a C1-C4 methyl group, y is a natural number between 0 and 4, and R B It is a C2-C6 alkylene group. More preferably, in formula (IV), y is 0, and the two carbonyl groups on the benzene ring are arranged in a para or meta position; in formula (V), R... B It is a C2-C4 alkylene group. Through the combination of structural unit d, structural unit e, and the aforementioned structural units and attapulgite, the T of the polyester can be further improved. mc Temperature and reducing the T of polyester c The alkali reduction of polyester is increased simultaneously with the increase in temperature.

[0035] Preferably, the modified polyester further contains a metal element selected from at least one of antimony, titanium, germanium, and aluminum. Studies have found that the simultaneous presence of the aforementioned metal elements in the modified polyester can further improve the polyester's T (temperature resistance). mc Temperature and reduce the T of polyester c Increasing temperature simultaneously increases the alkali reduction of polyester. This can further improve the T... mc Temperature and reduce the T of polyester c Taking into account temperature and increasing the alkali reduction of the polyester, more preferably, the metal element is antimony. More preferably, the content of the metal element in the modified polyester is 5-300 ppm.

[0036] Preferably, the modified polyester further contains phosphorus (P), and the content of P in the modified polyester is 5-300 ppm. Studies have found that the presence of phosphorus in the polyester, and with the phosphorus content controlled within the above range, can further increase the melting and crystallization temperature (T0) of the polyester. mc And lower the cold crystallization temperature (T) of polyester. c ).

[0037] Preferably, the modified polyester has a melt crystallization temperature of 183-190℃ and a cold crystallization temperature of 130-137℃, and the modified polyester has an alkali reduction of 16-19% in 15 minutes, an alkali reduction of 24-26% in 20 minutes, and an alkali reduction of 25-27% in 25 minutes.

[0038] According to the present invention, the melting and crystallization temperature (T) mc ) and cold crystallization temperature (T cThe intrinsic viscosity was calculated based on differential scanning calorimetry (DSC) and obtained according to GB / T14190-2017. The alkali loss test method is as follows: 1g of polyester fiber obtained from spinning is added to a 1wt% sodium hydroxide aqueous solution and cooked at 100℃. After cooking for the appropriate time, the fiber is removed, dried to constant weight, and its mass is measured. The alkali loss is calculated based on the mass of the cooked fiber and its original mass.

[0039] Preferably, the attapulgite clay has a length of less than 3 μm and a diameter of less than 50 nm. This results in a higher alkali reduction rate for the polyester.

[0040] A second aspect of the present invention provides a method for preparing a modified polyester, comprising the following steps:

[0041] S1. Under esterification conditions, a dicarboxylic acid monomer, a diol monomer, a catalyst, and an auxiliary agent are subjected to contact reaction I to obtain the reactants;

[0042] The additive contains attapulgite and a diol having the structure shown in structural unit a, wherein structural unit a contains a naphthalene ring structure and a C1-C4 alkylene group attached to the naphthalene ring structure, and the C1-C4 alkylene group is attached to the naphthalene ring structure via a C-C bond.

[0043] S2. Under polymerization conditions, the reactants and a dihydroxy ester sulfonate containing the structure shown in formula (I) are subjected to a contact reaction II.

[0044]

[0045] The modified polyester prepared by the above method has high T mc Temperature and lower polyester T c The temperature facilitates rapid drying of the polyester and effectively increases its crystallization rate. This polyester also exhibits good water solubility. Furthermore, the fibers prepared from this polyester show high alkali loss.

[0046] Preferably, in structural unit a, an even number of C1-C4 alkylene oxides are provided, and the even number of C1-C4 alkylene oxides are symmetrically arranged on the naphthalene ring structure. By limiting the number of C1-C4 alkylene oxides on structural unit a to an even number and symmetrically arranging them on the naphthalene ring structure, the T of the polyester can be further improved. mc Temperature and reduce the T of polyester c Increasing temperature simultaneously increases the alkali reduction of polyester. This allows for further improvement in the T... mc Temperature and reduce the T of polyester c Taking into account temperature and increasing the alkali reduction of polyester, more preferably, the structure of structural unit a is as shown in formula (II).

[0047]

[0048] Among them, R I and R III It is a C1-C4 alkylene group, R II and R IV Each of the four groups (C1-C4) is an independently formed alkyl or hydrogen atom, where m, n, and x are all natural numbers, and R... II and R IV The settings are symmetrical, m+n≤4, x+n≤4, n≥1.

[0049] Preferably, R II and R IV It is a C1-C2 alkyl or hydrogen, m = x, and R I and R III Symmetrical setting, R I and R III It is a C1-C2 alkylene group. R I R II R III and R IV By controlling the T of polyester within the above range, the T can be further improved. mc Temperature and reduce the T of polyester c Increasing temperature simultaneously increases the alkali reduction of polyester. This can further improve the T... mc Temperature and reduce the T of polyester c Taking temperature and increasing the alkali reduction of polyester into consideration, further preferably, R I and R III It is a methylene group. More preferably, n is 1, m is 3, x is 3, and R is... II and R IV It is hydrogen.

[0050] Preferably, based on the theoretical yield of the modified polyester, the amount of the diol having the structure shown in structural unit a is 0.01-0.06 wt%, the amount of the attapulgite is 0.3-3.2 wt%, and the amount of the dihydroxy ester sulfonate containing the structure shown in formula (I) is 13.5-18.5 wt%. The modified polyester prepared under the above conditions has a higher Tg. mc Temperature and lower T c The alkali reduction of the polyester is increased simultaneously with the temperature. Preferably, the amount of the diol having the structure shown in structural unit a is 0.01-0.05 wt%, the amount of the attapulgite is 0.3-2 wt%, and the amount of the dihydroxy ester sulfonate containing the structure shown in formula (I) is 13.2-17.5 wt%. This allows for further improvement of the polyester's T... mc Temperature and reducing the T of polyester cTaking into account temperature and the alkali reduction of the polyester, more preferably, the mass ratio of the diol of the structure shown in structural unit a, the attapulgite, and the structural unit b is 1:5-260:250-1500. More preferably, the mass ratio of the diol of the structure shown in structural unit a, the attapulgite, and the structural unit b is 1:6-55:300-500.

[0051] Preferably, the dihydroxy ester sulfonate containing the structure shown in formula (I) can be sodium dihydroxyethyl isophthalate-5-sulfonate.

[0052] Preferably, a polydiol is also added in contact reaction III.

[0053] Preferably, the polydiol is selected from at least one of polyethylene glycol, polypropylene glycol, and polybutanediol. Preferably, the diacid monomer is terephthalic acid, and the diol monomer is ethylene glycol.

[0054] Preferably, the molecular weight of the polydiol is 1500-2500. Controlling the molecular weight of the polydiol within this range can further improve the water solubility of the polyester. More preferably, considering the ability to further improve the water solubility of the polyester, the amount of the polydiol used is 9.5-13 wt%, based on the theoretical yield of the modified polyester.

[0055] Preferably, the catalyst is selected from at least one of antimony-based catalysts, titanium-based catalysts, germanium-based catalysts, and aluminum-based catalysts. More preferably, the catalyst is an antimony-based catalyst;

[0056] The amount of catalyst used can be determined by technicians based on the actual situation. Preferably, the amount of catalyst used, calculated as metal, is 5-300 ppm based on the theoretical yield of the modified polyester.

[0057] Preferably, the additives further contain a phosphorus-containing stabilizer. The amount of stabilizer can be determined by a technician based on the actual situation. Preferably, based on the theoretical yield of the modified polyester, the amount of the phosphorus-containing stabilizer, calculated as phosphorus, is 5-300 ppm.

[0058] Preferably, the phosphorus-containing stabilizer is selected from at least one of phosphoric acid, phosphorous acid, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, and triethyl phosphoroacetate. Phosphoric acid is preferred.

[0059] Preferably, the esterification conditions include at least: a nitrogen atmosphere, a temperature of 220-260°C, and a gauge pressure of 0.2-0.25 MPa. The polymerization conditions include at least: a temperature of 275-290°C and an absolute pressure of less than 200 Pa.

[0060] Preferably, the attapulgite can be first prepared into a dispersion and then added to the esterification system. When preparing the attapulgite dispersion, a dispersant can be used, preferably polyethylene glycol with a molecular weight of 200-500.

[0061] Preferably, the length of the attapulgite clay is less than 3 μm and the diameter is less than 50 nm. This results in a polyester with a high alkali reduction rate.

[0062] Preferably, the dicarboxylic acid monomer is a dicarboxylic acid having the structure shown in formula (IV), and the diol monomer is selected from at least one of ethylene glycol, propylene glycol, and butanediol;

[0063] Wherein, R1 is a C1-C4 methyl group, and y is a natural number between 0 and 4. More preferably, y is 0, and the two carbonyl groups on the benzene ring structure are arranged in a para or meta position.

[0064] According to a particularly preferred embodiment of the present invention, a method for preparing a modified polyester is provided, comprising the following steps:

[0065] S1. Mix attapulgite clay with a length of less than 3μm and a diameter of less than 50nm, polyethylene glycol with a molecular weight of 200-500, and water to obtain an attapulgite clay dispersion.

[0066] S2. Terephthalic acid, ethylene glycol, antimony-based catalyst, attapulgite dispersion, diol with the structure shown in formula (II), and phosphoric acid are subjected to contact reaction I under a nitrogen atmosphere, at a temperature of 220-260℃ and a gauge pressure of 0.2-0.25MPa to obtain the reactants.

[0067] The additive contains attapulgite and a diol having the structure shown in formula (II).

[0068]

[0069] Among them, R I and R III It is a C1-C4 alkylene group, R II and R IV It is a C1-C4 alkyl or hydrogen, R I and R III Symmetrical setting, R II and R IV Symmetrical settings, m+n≤4, x+n≤4, n≥1;

[0070] S3. The reactants, dihydroxy ester sulfonate containing the structure shown in formula (I) and polyethylene glycol are subjected to contact reaction II at a temperature of 275-290℃ and an absolute pressure of less than 200Pa.

[0071] The diacid monomer is a diacid having the structure shown in formula (IV), the diol monomer is selected from at least one of ethylene glycol, propylene glycol and butanediol, the molecular weight of the polydiol is 1500-2500, and based on the theoretical yield of the modified polyester, the amount of the diol having the structure shown in structural unit a is 0.01-0.06 wt%, the amount of attapulgite is 0.3-3.2 wt%, the amount of the dihydroxy ester sulfonate containing the structure shown in formula (I) is 13.2-18.5 wt%, and the amount of the polydiol is 9.5-13 wt%.

[0072] Where R1 is a C1-C4 methyl group, and y is a natural number between 0 and 4.

[0073] The modified polyester prepared by the above method has a high Tmc temperature and a low Tc temperature.

[0074] The present invention will be described in detail below through embodiments. In the following embodiments, attapulgite clay was purchased from Jiangsu Aotebang Non-metallic Mining Co., Ltd., a commercially available product. Talc powder was purchased from Xufeng Powder Co., Ltd., under the brand name BHS818, a commercially available product.

[0075] In this invention, the glass transition temperature and melting point T of the polyester are... m Melting and crystallization temperature (T) mc ) and cold crystallization temperature (T c The intrinsic viscosity was calculated based on differential scanning calorimetry (DSC) testing, and the intrinsic viscosity was tested according to method 5.1 of GB / T14190-2017 Test Method for Fiber Grade Polyester Chips. The terminal carboxyl groups were tested according to method 5.4 of GB / T14190-2017 Test Method for Fiber Grade Polyester Chips. DEG was tested according to the method of GB / T14190-2008 Analytical Method for Fiber Grade Polyester Chips. The differential scanning calorimetry (DSC) testing process included: under nitrogen protection, DSC thermal analysis was performed by raising the temperature from 25℃ to 290℃ at a rate of 10℃ / min, holding for 5 min, then cooling to 25℃ at a rate of 400℃ / min, then raising the temperature from 25℃ to 290℃ again at a rate of 10℃ / min, holding for 5 min, and finally cooling to 100℃ at a rate of 10℃ / min.

[0076] Example 1

[0077] (1) 3000g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 15kg of water, stirred and dispersed, and then 30g of polyethylene glycol with a molecular weight of 200 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 20min and set aside. The dispersion was stored stably for 24 hours without separation.

[0078] (2) Add 102 kg of terephthalic acid, 66 kg of ethylene glycol, 15 g of 1,8-bis(hydroxymethyl)naphthalene, the above-mentioned attapulgite aqueous dispersion, 80 g of antimony acetate, and 20 g of phosphoric acid to a 300 L reactor, and start stirring. After replacing with N2 three times, pressurize and adjust the pressure inside the reactor to 0.25 MPa using the valve at the top of the fractionation column. Stir at 60 rpm and heat to 260 °C for esterification reaction. When the amount of water produced by esterification reaches the theoretical amount, release the pressure to end the esterification. Then add 55 kg of ES40 (40% by weight of sodium isophthalate dihydroxyethyl ester-5-sulfonate in ethylene glycol solution) and 15 kg of polyethylene glycol with a molecular weight of 2000. Heat and reduce pressure, adjust the stirring speed to 50 rpm, and carry out polycondensation reaction at 290 °C and an absolute pressure of less than 200 Pa. When the stirring power reaches the rated value, stop stirring, remove the vacuum, discharge the material, and granulate to obtain modified polyester chips.

[0079] Example 2

[0080] (1) 450g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 2500g of water, stirred and dispersed, and then 4.5g of polyethylene glycol with a molecular weight of 300 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 20min and set aside. The dispersion was stored stably for 24 hours without separation.

[0081] (2) Add 90 kg of terephthalic acid, 66 kg of ethylene glycol, 70 g of 1,8-bis(hydroxymethyl)naphthalene, the above-mentioned attapulgite aqueous dispersion, 80 g of antimony acetate, and 20 g of phosphoric acid to a 300 L reactor, and start stirring. After replacing with N2 three times, pressurize and adjust the pressure inside the reactor to 0.2 MPa using the valve at the top of the fractionation column. Stir at 80 rpm and heat to 220 °C for esterification reaction. When the amount of water produced by esterification reaches the theoretical amount, release the pressure to end the esterification. Then add 60 kg of ES40 (40% by weight of sodium isophthalate dihydroxyethyl ester-5-sulfonate in ethylene glycol solution) and 15.5 kg of polyethylene glycol with a molecular weight of 2000. Heat and reduce pressure, adjust the stirring speed to 60 rpm, and carry out polycondensation reaction at 275 °C and an absolute pressure of less than 200 Pa. When the stirring power reaches the rated value, stop stirring, remove the vacuum, discharge the material, and granulate to obtain modified polyester chips.

[0082] Example 3

[0083] (1) 1500g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 8000g of water, stirred and dispersed, and then 15g of polyethylene glycol with a molecular weight of 400 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 20min and set aside. The dispersion was stored stably for 24 hours without separation.

[0084] (2) Add 95 kg of terephthalic acid, 66 kg of ethylene glycol, 40 g of 1,8-bis(hydroxymethyl)naphthalene, the above-mentioned attapulgite aqueous dispersion, 80 g of antimony acetate, and 20 g of phosphoric acid to a 300 L reactor, and start stirring. After replacing with N2 three times, pressurize and adjust the pressure inside the reactor to 0.2 MPa using the valve at the top of the fractionation column. Stir at 80 rpm and heat to 220 °C for esterification reaction. When the amount of water produced by esterification reaches the theoretical amount, release the pressure to end the esterification. Then add 50 kg of ES40 (40% by weight of sodium isophthalate dihydroxyethyl ester-5-sulfonate in ethylene glycol solution) and 19 kg of polyethylene glycol with a molecular weight of 2000. Heat and reduce pressure, adjust the stirring speed to 60 rpm, and carry out polycondensation reaction at 275 °C and an absolute pressure of less than 200 Pa. When the stirring power reaches the rated value, stop stirring, remove the vacuum, discharge the material, and granulate to obtain modified polyester chips.

[0085] Example 4

[0086] (1) 450g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 2500g of water, stirred and dispersed, and then 4.5g of polyethylene glycol with a molecular weight of 450 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 20min and set aside. The dispersion was stored stably for 24 hours without separation.

[0087] (2) Add 102 kg of terephthalic acid, 66 kg of ethylene glycol, 7.5 g of 1,8-bis(hydroxymethyl)naphthalene, the above-mentioned attapulgite aqueous dispersion, 80 g of antimony acetate, and 20 g of phosphoric acid to a 300 L reactor, and start stirring. After replacing with N2 three times, pressurize and adjust the pressure inside the reactor to 0.25 MPa using the valve at the top of the fractionation column. Stir at 60 rpm and heat to 260 °C for esterification reaction. When the amount of water produced by esterification reaches the theoretical amount, release the pressure to end the esterification. Then add 55 kg of ES40 (40% by weight of sodium isophthalate dihydroxyethyl ester-5-sulfonate in ethylene glycol solution) and 15 kg of polyethylene glycol with a molecular weight of 2000. Heat and reduce pressure, adjust the stirring speed to 50 rpm, and carry out polycondensation reaction at 290 °C and an absolute pressure of less than 200 Pa. When the stirring power reaches the rated value, stop stirring, remove the vacuum, discharge the material, and granulate to obtain modified polyester chips.

[0088] Example 5

[0089] (1) 750g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 3000g of water, stirred and dispersed, and then 7.5g of polyethylene glycol with a molecular weight of 500 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 20min and set aside. The dispersion was stored stably for 24 hours without separation.

[0090] (2) Add 102 kg of terephthalic acid, 66 kg of ethylene glycol, 12 g of 1,8-bis(hydroxymethyl)naphthalene, the above-mentioned attapulgite aqueous dispersion, 80 g of antimony acetate, and 20 g of phosphoric acid to a 300 L reactor, and start stirring. After replacing with N2 three times, pressurize and adjust the pressure inside the reactor to 0.23 MPa using the valve at the top of the fractionation column. Stir at 70 rpm and heat to 240 °C for esterification reaction. When the amount of water produced by esterification reaches the theoretical amount, release the pressure to end the esterification. Then add 55 kg of ES40 (40% by weight of sodium isophthalate dihydroxyethyl ester-5-sulfonate in ethylene glycol solution) and 15 kg of polyethylene glycol with a molecular weight of 2000. Heat and reduce pressure, adjust the stirring speed to 55 rpm, and carry out polycondensation reaction at 280 °C and an absolute pressure of less than 200 Pa. When the stirring power reaches the rated value, stop stirring, remove the vacuum, discharge the material, and granulate to obtain modified polyester chips.

[0091] Example 6

[0092] (1) 2500g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 8000g of water, stirred and dispersed, and then 25g of polyethylene glycol with a molecular weight of 400 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 20min and set aside. The dispersion was stored stably for 24 hours without separation.

[0093] (2) Add 102 kg of terephthalic acid, 66 kg of ethylene glycol, 45 g of 1,8-bis(hydroxymethyl)naphthalene, the above-mentioned attapulgite aqueous dispersion, 80 g of antimony acetate, and 20 g of phosphoric acid to a 300 L reactor, and start stirring. After replacing with N2 three times, pressurize and adjust the pressure inside the reactor to 0.23 MPa using the valve at the top of the fractionation column. Stir at 70 rpm and heat to 240 °C for esterification reaction. When the amount of water produced by esterification reaches the theoretical amount, release the pressure to end the esterification. Then add 55 kg of ES40 (40% by weight of sodium isophthalate dihydroxyethyl ester-5-sulfonate in ethylene glycol solution) and 15 kg of polyethylene glycol with a molecular weight of 2000. Heat and reduce pressure, adjust the stirring speed to 55 rpm, and carry out polycondensation reaction at 280 °C and an absolute pressure of less than 200 Pa. When the stirring power reaches the rated value, stop stirring, remove the vacuum, discharge the material, and granulate to obtain modified polyester chips.

[0094] Example 7

[0095] Modified polyester chips were prepared according to the method described in Example 1, except that the amount of 1,8-bis(hydroxymethyl)naphthalene added was 90g.

[0096] Example 8

[0097] Modified polyester chips were prepared according to the method described in Example 2, except that in step (1), 4500g of commercially available purified attapulgite clay (length less than 3μm and diameter less than 50nm) was added to 25000g of water, stirred and dispersed, and then 45g of polyethylene glycol with a molecular weight of 300 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 20min and stored for later use. The dispersion was stable for 24 hours without separation.

[0098] Example 9

[0099] Modified polyester chips were prepared according to the method described in Example 1, except that in step (1), 4000g of commercially available purified attapulgite clay (length less than 3μm and diameter less than 50nm) was added to 20kg of water, stirred and dispersed, and then 40g of polyethylene glycol with a molecular weight of 200 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 20min and set aside. The dispersion was stored stably for 24 hours without stratification.

[0100] Example 10

[0101] Modified polyester chips were prepared according to the method described in Example 2, except that the amount of 1,8-bis(hydroxymethyl)naphthalene added was 85g.

[0102] Example 11

[0103] Modified polyester chips were prepared according to the method described in Example 2, except that the amount of ES40 used was 65 kg.

[0104] Example 12

[0105] Modified polyester chips were prepared according to the method described in Example 3, except that the amount of ES40 used was 45 kg.

[0106] Example 13

[0107] Modified polyester chips were prepared according to the method described in Example 1, except that 1,8-bis(hydroxymethyl)naphthalene was replaced with 2,3-bis(hydroxymethyl)naphthalene.

[0108] Example 14

[0109] Modified polyester chips were prepared according to the method described in Example 1, except that 1,8-bis(hydroxymethyl)naphthalene was replaced with 2,6-bis(hydroxymethyl)naphthalene.

[0110] Example 15

[0111] Modified polyester chips were prepared according to the method described in Example 1, except that in step (2), polyethylene glycol with a molecular weight of 2000 was replaced with polypropylene glycol with a molecular weight of 1500.

[0112] Example 16

[0113] Modified polyester chips were prepared according to the method described in Example 1, except that polyethylene glycol was not added in step (2).

[0114] Comparative Example 1

[0115] (1) 2500g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 8000g of water, stirred and dispersed, and then 25g of polyethylene glycol with a molecular weight of 400 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 20min and set aside. The dispersion was stored stably for 24 hours without separation.

[0116] (2) Add 102 kg of terephthalic acid, 66 kg of ethylene glycol, the above-mentioned attapulgite aqueous dispersion, 80 g of antimony acetate, and 20 g of phosphoric acid to a 300 L reactor, and start stirring. After replacing with N2 three times, pressurize and adjust the pressure inside the reactor to 0.23 MPa using the valve at the top of the fractionation column. Stir at 70 rpm and heat to 240 °C for esterification reaction. When the amount of water produced by esterification reaches the theoretical amount, release the pressure to end the esterification. Then add 55 kg of ES40 (40% by weight of sodium isophthalate dihydroxyethyl ester-5-sulfonate in ethylene glycol solution) and 15 kg of polyethylene glycol with a molecular weight of 2000. Heat and reduce pressure, adjust the stirring speed to 55 rpm, and carry out polycondensation reaction at 280 °C and an absolute pressure of less than 200 Pa. When the stirring power reaches the rated value, stop stirring, remove the vacuum, discharge the material, and granulate to obtain modified polyester chips.

[0117] Comparative Example 2

[0118] In a 300L reactor, add 102kg of terephthalic acid, 66kg of ethylene glycol, 45g of 1,8-bis(hydroxymethyl)naphthalene, 80g of antimony acetate, and 20g of phosphoric acid, and start stirring. After three purgings with N2, pressurize the reactor and adjust the pressure to 0.23MPa using the valve at the top of the fractionation column. Stir at 70rpm and heat to 240℃ for esterification. When the amount of water produced by esterification reaches the theoretical amount, release the pressure to end the esterification. Then add 55kg of ES40 (40% by weight of sodium isophthalate dihydroxyethyl ester-5-sulfonate in ethylene glycol) and 15kg of polyethylene glycol with a molecular weight of 2000. Heat and reduce the pressure, adjust the stirring speed to 55rpm, and carry out polycondensation reaction at 280℃ and an absolute pressure of less than 200Pa. When the stirring power reaches the rated value, stop stirring, remove the vacuum, discharge the material, and pelletize to obtain modified polyester chips.

[0119] Comparative Example 3

[0120] (1) 3000g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 15000g of water, stirred and dispersed, and then 30g of polyethylene glycol with a molecular weight of 200 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 20min and set aside. The dispersion was stored stably for 24 hours without separation.

[0121] (2) Add 102 kg of terephthalic acid, 66 kg of ethylene glycol, the above-mentioned attapulgite aqueous dispersion, 80 g of antimony acetate, and 20 g of phosphoric acid to a 300 L reactor, and start stirring. After replacing with N2 three times, pressurize and adjust the pressure inside the reactor to 0.25 MPa using the valve at the top of the fractionation column. Stir at 60 rpm and heat to 260 °C for esterification reaction. When the amount of water produced by esterification reaches the theoretical amount, release the pressure to end the esterification. Then add 55 kg of ES40 (40% by weight of sodium isophthalate dihydroxyethyl ester-5-sulfonate in ethylene glycol solution) and 15 kg of polyethylene glycol with a molecular weight of 2000. Heat and reduce the pressure, adjust the stirring speed to 50 rpm, and carry out polycondensation reaction at 290 °C and an absolute pressure of less than 200 Pa. When the stirring power reaches the rated value, stop stirring, remove the vacuum, discharge the material, and granulate to obtain modified polyester chips.

[0122] Comparative Example 4

[0123] Add 102 kg of terephthalic acid, 66 kg of ethylene glycol, 15 g of 1,8-bis(hydroxymethyl)naphthalene, 80 g of antimony acetate, and 20 g of phosphoric acid to a 300 L reactor and start stirring. After three purgings with N2, pressurize the reactor and adjust the pressure to 0.25 MPa using the valve at the top of the fractionation column. Stir at 60 rpm and heat to 260 °C for esterification. When the amount of water produced by esterification reaches the theoretical amount, release the pressure to end the esterification. Then add 55 kg of ES40 (40% by weight of sodium isophthalate dihydroxyethyl ester-5-sulfonate in ethylene glycol) and 15 kg of polyethylene glycol with a molecular weight of 2000. Heat and reduce the pressure, adjust the stirring speed to 50 rpm, and carry out polycondensation reaction at 290 °C and an absolute pressure of less than 200 Pa. When the stirring power reaches the rated value, stop stirring, remove the vacuum, discharge the material, and pelletize to obtain modified polyester chips.

[0124] Comparative Example 5

[0125] Add 102 kg of terephthalic acid, 66 kg of ethylene glycol, 80 g of antimony acetate, and 20 g of phosphoric acid to a 300 L reactor and start stirring. After three purgings with N2, pressurize the reactor and adjust the pressure to 0.25 MPa using the valve at the top of the fractionation column. Stir at 60 rpm and heat to 260 °C for esterification. When the amount of water produced by esterification reaches the theoretical amount, release the pressure to end the esterification. Then add 55 kg of ES40 (40% by weight of sodium dihydroxyethyl isophthalate-5-sulfonate in ethylene glycol) and 15 kg of polyethylene glycol with a molecular weight of 2000. Heat and reduce the pressure, adjust the stirring speed to 50 rpm, and carry out polycondensation reaction at 290 °C and an absolute pressure of less than 200 Pa. When the stirring power reaches the rated value, stop stirring, remove the vacuum, discharge the material, and granulate to obtain modified polyester chips.

[0126] Comparative Example 6

[0127] Add 150 kg of terephthalic acid, 78 kg of ethylene glycol, 90 g of antimony acetate, and 20 g of phosphoric acid to a 300 L reactor and start stirring. After three purgings with N2, pressurize the reactor and adjust the pressure to 0.23 MPa using the valve at the top of the fractionation column. Stir at 70 rpm and heat to 240 °C for esterification. Once the esterification water output reaches the theoretical amount, release the pressure to end the esterification. Then, increase the temperature and reduce the pressure, adjust the stirring speed to 55 rpm, and carry out polycondensation at 280 °C and an absolute pressure less than 200 Pa. Stop stirring when the stirring power reaches the rated value, remove the vacuum, discharge the material, and granulate to obtain modified polyester chips.

[0128] Comparative Example 7

[0129] Modified polyester chips were prepared according to the method described in Example 6, except that 1,8-bis(hydroxymethyl)naphthalene was replaced with sodium benzoate.

[0130] Comparative Example 8

[0131] Modified polyester chips were prepared according to the method described in Example 6, except that attapulgite was replaced with talc.

[0132] The parameters of the polyesters obtained in the examples and comparative examples are shown in Table 1.

[0133] Table 1

[0134]

[0135] The physical and chemical properties of polyester are shown in Table 2.

[0136] Table 2

[0137]

[0138]

[0139] As can be seen from the results in Table 2, the alkali reduction of the polyester obtained in the examples is higher than that of the polyester obtained in the comparative example. The T0 of the polyester obtained in the examples... mc The temperature is higher than that of the polyester obtained in the comparative example. mc Temperature, T of the polyester obtained in the examples c The temperature was lower than the T of the polyester obtained in the comparative example. c Temperature indicates that the polyester contains attapulgite, structural unit a, and structural unit b, which can effectively improve the alkali reduction and T of the polyester. mc Temperature, lowers the T of polyester c The polyester provided by this invention can be dried quickly, has a high crystallization rate, and the clothing made from this polyester has a high level of comfort.

[0140] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A modified polyester, characterized in that, The modified polyester contains attapulgite, structural unit a, and structural unit b. Structural unit a contains a naphthalene ring structure and C1-C4 alkylene groups attached to the naphthalene ring structure. The C1-C4 alkylene groups are connected to the naphthalene ring structure via C-C bonds. The structure of structural unit b is shown in formula (I).

2. The modified polyester according to claim 1, characterized in that, In the naphthalene ring structure, there are an even number of C1-C4 alkylene groups, and the even number of C1-C4 alkylene groups are symmetrically arranged in the naphthalene ring structure; Preferably, the structure of structural unit a is as shown in equation (II). Among them, R I and R III It is a C1-C4 alkylene group, R II and R IV Each is independently C1-C4 alkyl or hydrogen, R I and R III The values ​​are symmetrically set, where m, n, and x are all natural numbers, and m+n≤4, x+n≤4, and n≥1; Preferably, R II and R IV It is a C1-C2 alkyl or hydrogen, m = x, and R II and R IV Symmetrical setting, R I and R III It is a C1-C2 alkylene group, more preferably a methylene group; Preferably, n is 1, m is 3, x is 3, and R II and R IV It is hydrogen.

3. The modified polyester according to claim 1 or 2, characterized in that, In the modified polyester, the content of structural unit a is 0.01-0.06 wt%, preferably 0.01-0.05 wt%; the content of attapulgite is 0.3-3.2 wt%, preferably 0.3-2 wt%; and the content of structural unit b is 13.2-18.5 wt%, preferably 13.5-17.5 wt%. Preferably, the mass ratio of the structural unit a, the attapulgite soil, and the structural unit b is 1:5-260:250-1500, and more preferably 1:6-55:300-500.

4. The modified polyester according to claim 1 or 2, characterized in that, The modified polyester also contains the structural unit c shown in formula (III). Among them, R A It is a C2-C4 alkylene group, preferably a C2 alkylene group, and n is a natural number of 30-55, preferably a natural number of 35-45; Preferably, in the modified polyester, the content of the structural unit c is 9.5-13 wt%.

5. The modified polyester according to claim 1 or 2, characterized in that, The modified polyester also contains a metal element, which is selected from at least one of antimony, titanium, germanium and aluminum, preferably antimony; Preferably, the content of the metal element in the modified polyester is 5-300 ppm; Preferably, the modified polyester further contains phosphorus (P); the content of P in the modified polyester is 5-300 ppm. Preferably, the modified polyester has a melt crystallization temperature of 183-190℃ and a cold crystallization temperature of 130-137℃, and the modified polyester has an alkali reduction of 16-19% in 15 minutes, an alkali reduction of 24-26% in 20 minutes, and an alkali reduction of 25-27% in 25 minutes.

6. A method for preparing a modified polyester, characterized in that, Includes the following steps: S1. Under esterification conditions, a dicarboxylic acid monomer, a diol monomer, a catalyst, and an auxiliary agent are subjected to contact reaction I to obtain the reactants; The additive contains attapulgite and a diol having the structure shown in structural unit a, wherein structural unit a contains a naphthalene ring structure and a C1-C4 alkylene group attached to the naphthalene ring structure, and the C1-C4 alkylene group is attached to the naphthalene ring structure via a C-C bond. S2. Under polymerization conditions, the reactants and a dihydroxy ester sulfonate containing the structure shown in formula (I) are subjected to a contact reaction II; 7. The preparation method according to claim 6, characterized in that, In the naphthalene ring structure, there are an even number of C1-C4 alkylene groups, and the even number of C1-C4 alkylene groups are symmetrically arranged in the naphthalene ring structure; Preferably, the structure of structural unit a is as shown in equation (II). Among them, R I and R III It is a C1-C4 alkylene group, R II and R IV Each is independently C1-C4 alkyl or hydrogen, R I and R III The values ​​are symmetrically set, where m, n, and x are all natural numbers, and m+n≤4, x+n≤4, and n≥1; Preferably, R II and R IV It is a C1-C2 alkyl or hydrogen, m = x, and R II and R IV Symmetrical setting, R I and R III It is a C1-C2 alkylene group, more preferably a methylene group; Preferably, n is 1, m is 3, x is 3, and R II and R IV It is hydrogen; Preferably, based on the theoretical yield of the modified polyester, the amount of the diol having the structure shown in structural unit a is 0.01-0.06 wt%, preferably 0.01-0.05 wt%; the amount of the attapulgite is 0.3-3.2 wt%, preferably 0.3-2 wt%; and the amount of the dihydroxy ester sulfonate containing the structure shown in formula (I) is 13.2-18.5 wt%, preferably 13.5-17.5 wt%. Preferably, the mass ratio of the diol with the structure shown in structural unit a, the attapulgite, and the dihydroxy ester sulfonate containing the structure shown in formula (I) is 1:5-260:250-1500, and more preferably 1:6-55:300-500.

8. The preparation method according to claim 6 or 7, characterized in that, In the contact reaction III, a polydiol was also added; Preferably, the length of the attapulgite clay is less than 3 μm and the diameter is less than 50 nm; the polydiol is selected from at least one of polyethylene glycol, polypropylene glycol and polybutanediol, and more preferably polyethylene glycol; Preferably, the molecular weight of the polydiol is 1500-2500; Preferably, the amount of the polydiol used is 9.5-13 wt%, based on the theoretical yield of the modified polyester.

9. The preparation method according to claim 6 or 7, characterized in that, The diacid monomer is a diacid having the structure shown in formula (IV), and the diol monomer is selected from at least one of ethylene glycol, propylene glycol, and butanediol. Where R1 is a C1-C4 methyl group, and y is a natural number between 0 and 4; Preferably, y is 0, and the two carbonyl groups on the benzene ring structure are arranged in a para or meta position.

10. The preparation method according to claim 6 or 7, characterized in that, The catalyst is selected from at least one of antimony-based catalysts, titanium-based catalysts, germanium-based catalysts, and aluminum-based catalysts; Preferably, the amount of catalyst used, calculated as metal, is 5-300 ppm based on the theoretical yield of the modified polyester. Preferably, the additives further contain a phosphorus-containing stabilizer, and the amount of the phosphorus-containing stabilizer, calculated as phosphorus, is 5-300 ppm based on the theoretical yield of the modified polyester. Preferably, the phosphorus-containing stabilizer is selected from at least one of phosphoric acid, phosphorous acid, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, and triethyl phosphoroacetate.

Images