Nucleating systems and their use, aliphatic-aromatic polyesters and their use

Abstract

The present application relates to nucleating agent, disclose a kind of nucleating system and its application, aliphatic aromatic polyester and its application.The nucleating system contains mixed storage or each independent storage nucleating agent A and nucleating agent B, the nucleating agent A contains naphthalene ring structure and the hydroxyl-substituted C1-C4 alkyl connected on the naphthalene ring structure, the nucleating agent B is attapulgite.The nucleating system has good dispersion effect in polyester, and can effectively improve the crystallization rate of polyester, so that the obtained polyester has higher impact strength and shore hardness.

Description

Technical Field

[0001] This invention relates to nucleating agents, specifically to a nucleating system and its applications. Furthermore, this invention also relates to an aliphatic aromatic polyester prepared using the above-described nucleating system and its applications. Background Technology

[0002] The synthetic resins used in the production of plastic sheets in my country mainly include polyvinyl chloride (PVC), polypropylene, polystyrene (PP), polymethyl methacrylate (PMMA), polyethylene, and PET (polyester). PET sheets possess superior properties not found in other materials, including high safety and strong plasticity. They meet national health standards and international environmental requirements, making them a new generation of recyclable and environmentally friendly materials. In Europe and America, crystalline PET sheets have replaced materials such as PS and PVC. Due to their advantages of scratch resistance, antibacterial properties, sound absorption, insulation, temperature resistance, and good mechanical properties, they are widely used in the manufacture of microwave oven trays, irregularly shaped plastic parts, automotive parts, various containers, and packaging for electronic and electrical products. Currently, most PET sheets on the domestic market are bottle-grade PET polyester. While bottle-grade PET polyester can meet the performance requirements of some sheet markets, it cannot meet the requirements for irregularly shaped plastic sheets and other high-strength, high-toughness sheets. Furthermore, it is prone to yellowing, horizontal streaks, or watermarks during production.

[0003] CN115260465A discloses a method for preparing rapidly crystallizing polyester chips. The method involves placing an inorganic nucleating agent in ethylene glycol, treating it to obtain an inorganic nucleating agent-ethylene glycol dispersion, and then stirring it with a coupling agent, water, and solvent to obtain a surface-modified inorganic nano-nucleating agent-ethylene glycol dispersion. This dispersion is then subjected to esterification and polycondensation reactions with terephthalic acid, ethylene glycol, and a polymerization catalyst, followed by granulation to obtain rapidly crystallizing polyester chips. This invention can improve the nucleation effect, enhance the dispersibility and compatibility of the nucleating agent in PET, and improve the crystallization properties of the chips.

[0004] CN115257019B discloses a high-strength PET composite board and its processing technology. Bacterial cellulose is modified in a phthalic acid solution, washed, and dried to obtain bacterial cellulose A. Bacterial cellulose A is dispersed in water, and citric acid and glycerol are added and stirred to form a transparent viscous liquid. Two polyethylene terephthalate sheets are taken and subjected to single-sided plasma treatment, denoted as sheet A and sheet B, respectively. The transparent viscous liquid is coated on the plasma-treated surface of sheet A, covering sheet B. The plasma-treated surface of sheet B is in contact with the transparent viscous liquid. The sheet is placed in a hot rolling mill, extruded, and cooled and calendered to obtain a high-strength PET composite board.

[0005] CN106928668A discloses a modified PET thick sheet and its extrusion molding method. The thick sheet is made by processing modified PET, using PET, processing modifier, plasticizer, filler, stabilizer and lubricant blended together. The heat resistance and resistance to processing deformation are greatly improved. The thick sheet has good toughness, excellent temperature resistance and weather resistance, and excellent comprehensive performance.

[0006] CN104530664B discloses a sheet material based on modified PET, a processing method, and processing equipment. The main raw material is a polyacid or polyol copolymerized modified PET resin with an intrinsic viscosity range of 0.8-1.2 dL / g, terminal carboxyl groups ≥30 mol / t, DEG <1.0%, and a melting point of 180-250℃. After drying, the resin is fully melt-blended with plasticizers, compatibilizers, nucleating agents, and antioxidants in a screw extruder. The resulting material then undergoes a chemical reaction with reactive modifiers in a second screw extruder, followed by further reaction and pressure stabilization in a third screw extruder before extrusion and shaping, and finally shearing into sheets. The resulting sheets have advantages such as high impact strength and high heat distortion temperature, and can replace materials such as ABS and PC.

[0007] Existing technologies primarily modify PET through copolymerization by adding nucleating agents such as sodium benzoate and bicarbonate during esterification. During blending, various materials such as PET blending plasticizers, nanoparticles, and lubricants are added to enhance the mechanical properties of the sheets. Additionally, multilayer composite thick sheets are prepared by modifying polyester and glass fiber, improving the crystallization rate, toughness, and mechanical properties of the polyester sheets through modified copolymerization, blending, or multilayer composite processes. However, existing technologies still suffer from drawbacks such as incompatibility between nucleating agents or additive systems and the PET system, limited improvement in the crystallization rate of the prepared polyester sheets, difficulty in solid-phase thickening with limited viscosity improvement, high difficulty in injection molding, appearance of horizontal streaks or watermarks on the sheets, and difficulty in dispersing nanoparticles, leading to agglomeration or precipitation. Furthermore, the polyester system is difficult to achieve homogeneity, and the required toughness is not met. Summary of the Invention

[0008] The purpose of this invention is to overcome the problems of poor compatibility and limited crystallization rate of the nucleation system in polyester in the prior art, and to provide a nucleation system and its application, aliphatic aromatic polyester and its application. The nucleation system has a good dispersion effect in polyester and can effectively improve the crystallization rate of polyester. The resulting polyester has high impact strength and Shore hardness.

[0009] To achieve the above objectives, the first aspect of the present invention provides a nucleation system containing nucleating agent A and nucleating agent B, which are stored together or separately. The nucleating agent A contains a naphthalene ring structure and a C1-C4 alkyl group substituted with a hydroxyl group attached to the naphthalene ring structure. The nucleating agent B is attapulgite.

[0010] A second aspect of the present invention provides an application of the above-described nucleation system in polyester.

[0011] A third aspect of the present invention provides an aliphatic aromatic polyester, wherein the polyester contains attapulgite and structural unit a, wherein the structural unit a contains a naphthalene ring structure and C1-C4 alkylene oxides connected to the naphthalene ring structure, and the C1-C4 alkylene oxides are connected to the naphthalene ring structure via C-C bonds.

[0012] A fourth aspect of the present invention provides the application of the above-mentioned aliphatic aromatic polyester in the preparation of sheet materials.

[0013] Through the above technical solution, the nucleation system provided by this invention exhibits good compatibility with polyester during the polyester preparation process. It accelerates the polyester crystallization rate, resulting in a more compact and ordered molecular weight arrangement, lower intermolecular porosity, and enhanced intermolecular interaction forces. Combined with the effect of microcrystalline physical cross-linking, this imparts better hardness and impact strength to the polyester material. The nucleation system also demonstrates good dispersion in polyester materials, and its relatively low addition amount effectively reduces the appearance of horizontal lines and watermarks on the sheet material. Detailed Implementation

[0014] 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.

[0015] As previously stated, the first method of the present invention provides a nucleation system containing nucleating agent A and nucleating agent B, which are either stored together or stored independently. Nucleating agent A contains a naphthalene ring structure and a C1-C4 alkyl group substituted with a hydroxyl group attached to the naphthalene ring structure. Nucleating agent B is attapulgite.

[0016] According to the present invention, the hydroxyl-substituted C1-C4 alkyl group can be 1-hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxyn-propyl, 2-hydroxyn-propyl, 3-hydroxyn-propyl, 1-hydroxyisopropyl, 2-hydroxyisopropyl, 1-hydroxyn-butyl, 2-hydroxyn-butyl, 3-hydroxyn-butyl, 4-hydroxyn-butyl, 1-hydroxyisobutyl, 2-hydroxyisobutyl or 3-hydroxyisobutyl.

[0017] During their research, the inventors discovered that using nucleating agent A and nucleating agent B as the nucleation system, with nucleating agent A controlled to contain a naphthalene ring structure and hydroxyl-substituted C1-C4 alkyl groups attached to the naphthalene ring structure, and nucleating agent B controlled to be attapulgite, the interaction between the two results in good compatibility with polyester. This also accelerates the polyester crystallization rate, leading to a more compact and ordered molecular weight arrangement, reduced intermolecular porosity, and enhanced intermolecular forces. Combined with the effect of microcrystalline physical cross-linking, this imparts better hardness and impact strength to the polyester material, resulting in better applications for the subsequently prepared sheets. This nucleation system exhibits good dispersion in polyester materials, and the relatively small amount added effectively reduces the appearance of horizontal lines and watermarks on the sheets.

[0018] Preferably, in the naphthalene ring structure, there are an even number of hydroxyl-substituted C1-C4 alkyl groups, and the even number of hydroxyl-substituted C1-C4 alkyl groups are symmetrically connected in the naphthalene ring structure. The nucleating agent A described above has a better interaction effect with attapulgite, and its application to polyester materials can further improve the hardness and impact strength of the polyester materials.

[0019] 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.

[0020] From the perspective of further improving the hardness and impact strength of the resulting polyester, more preferably, the structure of the nucleating agent A is as shown in formula (I).

[0021]

[0022] 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.

[0023] 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.

[0024] Preferably, R IIand 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 temperature within the above range, the hardness and impact strength of the obtained polyester can be further improved. From the perspective of further improving the hardness and impact strength of the obtained polyester, R is further preferably... 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.

[0025] Preferably, the mass ratio of nucleating agent A to nucleating agent B is 1:5-200, specifically 1:5, 1:50, 1:100, 1:150, 1:200, or any value between these ratios. Controlling the mass ratio of nucleating agent A to nucleating agent B within the above range can further improve the effect of nucleating agent A and nucleating agent B, thereby further improving the hardness and impact strength of the obtained polyester. More preferably, the mass ratio of nucleating agent A to nucleating agent B is 1:20-150.

[0026] Preferably, the length of the attapulgite is ≤3μm and the diameter is ≤50nm. Controlling the length of the attapulgite within the above range can further improve its interaction with nucleating agent A, thereby further improving the hardness and impact strength of the obtained polyester.

[0027] A second aspect of this invention provides an application of the above-described nucleation system in polyester. Applying this nucleation system to polyester exhibits good compatibility with polyester, accelerates the polyester crystallization rate, results in a more compact and ordered molecular weight arrangement, reduces intermolecular porosity, enhances intermolecular interaction forces, and facilitates the physical cross-linking of microcrystals, thereby imparting better hardness and impact strength to the polyester material. Furthermore, it effectively reduces the appearance of horizontal lines and watermarks on the sheet material.

[0028] Preferably, the polyester is an aliphatic aromatic polyester. This aliphatic aromatic polyester can be a polyester formed from an aliphatic diol and an aromatic diacid, or a polyester formed from an aliphatic diacid and an aromatic diol. The above-mentioned nucleation system has a better effect on aliphatic aromatic polyesters, and can further improve the hardness and impact strength of the polyester material.

[0029] Preferably, the aliphatic aromatic polyester is a polyester formed from an aliphatic diol and an aromatic diacid. More preferably, the polyester is polyethylene terephthalate.

[0030] A third aspect of the present invention provides an aliphatic aromatic polyester, wherein the polyester contains attapulgite and structural unit a, wherein the structural unit a contains a naphthalene ring structure and C1-C4 alkylene oxides connected to the naphthalene ring structure, and the C1-C4 alkylene oxides are connected to the naphthalene ring structure via C-C bonds.

[0031] According to the present invention, the C1-C4 alkylene oxides can be methylene oxide (methylene oxide), ethyl oxide (ethoxy oxide), n-propyl oxide (n-propoxy oxide), isopropyl oxide (isopropoxy oxide), n-butyl oxide (n-butoxy oxide), isobutyl oxide (isobutoxy oxide), or tert-butyl oxide (tert-butoxy oxide).

[0032] Studies have found that aliphatic aromatic polyesters contain both attapulgite and the aforementioned structural unit a. Through the interaction between attapulgite and structural unit a, the polyester crystallization rate can be accelerated, the molecular weight arrangement can be made more compact and orderly, the intermolecular porosity can be reduced, and the intermolecular interaction force can be enhanced. Combined with the effect of microcrystal physical cross-linking, the material is endowed with better hardness and impact strength, which facilitates the application of the subsequently prepared sheets.

[0033] Preferably, an even number of C1-C4 alkylene oxides are provided on the naphthalene ring structure, and the even number of C1-C4 alkylene oxides are symmetrically arranged on the naphthalene ring structure. The above-mentioned structural unit a and attapulgite have a better synergistic effect, which can further improve the hardness and impact strength of the polyester material.

[0034] From the perspective of further improving the hardness and impact resistance of polyester, preferably, the structure of structural unit a is as shown in formula (I).

[0035]

[0036] 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.

[0037] Preferably, R II and R IV It is a C1-C2 alkyl or hydrogen, m = x, and R II and RIV 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 temperature within the above range, the hardness and impact strength of the polyester can be further improved. Considering the ability to further improve the hardness and impact strength of the polyester, R is further preferably... 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.

[0038] Preferably, in the polyester, the content of structural unit a is 1-200 ppm, and the content of attapulgite is 1000-30000 ppm. Controlling the content of structural unit a and attapulgite in the polyester within the above ranges can further improve the interaction between structural unit a and attapulgite, thereby further improving the hardness and impact strength of the polyester. Further preferably, considering the ability to further improve the hardness and impact strength of the polyester, the mass ratio of structural unit a to attapulgite is 1:5-200. Even more preferably, the mass ratio of structural unit a to attapulgite is 1:20-150.

[0039] Preferably, the polyester further contains a metallic element selected from at least one of antimony, titanium, germanium, and aluminum. Studies have found that the simultaneous presence of the aforementioned metallic element in the polyester can further improve its hardness and impact resistance. Further preferably, considering the ability to further improve the hardness and impact resistance of the polyester, the content of the metallic element in the polyester is 5-300 ppm, specifically 5 ppm, 50 ppm, 100 ppm, 150 ppm, 200 ppm, 250 ppm, 300 ppm, or any value between these values.

[0040] Preferably, the polyester further comprises structural unit b as shown in formula (II) and structural unit c as shown in formula (III);

[0041]

[0042] -OR A -O- Equation (III),

[0043] Where R1 is a C1-C4 methyl group, y is a natural number between 0 and 4, and R AIt is a C2-C6 alkylene group. More preferably, in formula (II), y is 0, and the two carbonyl groups on the benzene ring are arranged in a para or meta position; in formula (III), R... A It is a C2-C4 alkylene group. The hardness and impact strength of polyester can be further improved through the combination of structural units a, b, and c with attapulgite.

[0044] Preferably, the polyester has a melt crystallization temperature of 188-202℃, a cold crystallization temperature of 120-132℃, and an impact strength of 65-80 J·m. -1 Its Shore hardness is 77-85D.

[0045] According to the present invention, the melting and crystallization temperature (T) mc ) and cold crystallization temperature (T c The impact strength was calculated based on differential scanning calorimetry (DSC) testing. The impact strength was obtained by testing the polyester composition in accordance with the national standard GB / T17037.1-2019 by injection molding standard specimens with dimensions of 80mm×10mm×4mm and a notch of 1mm. The Shore hardness was obtained in accordance with the national standard GB / T2411-2008.

[0046] Preferably, the preparation method of the above-mentioned aliphatic aromatic polyester includes the following steps:

[0047] 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;

[0048] The additive contains attapulgite, a diol having the structure shown in structural unit a, and a phosphorus-containing stabilizer. Structural unit a contains a naphthalene ring structure and a C1-C4 alkylene group attached to the naphthalene ring structure. The C1-C4 alkylene group is attached to the naphthalene ring structure via a C-C bond.

[0049] S2. Under polymerization conditions, the reactants are subjected to reaction II.

[0050] In the above preparation method, the additives have good dispersibility, the reaction rate of the diacid monomer and the diol monomer is fast and the esterification efficiency is high, and the prepared polyester material has high hardness and impact strength.

[0051] Preferably, the esterification conditions include at least: a nitrogen atmosphere, a temperature of 240-260℃, a gauge pressure of 0-0.4MPa, and a time of 2-4h. The polymerization conditions include at least: a temperature of 270-285℃ and an absolute pressure (vacuum) of less than 100Pa.

[0052] Preferably, the catalyst is selected from at least one of antimony-based catalysts, titanium-based catalysts, germanium-based catalysts, and aluminum-based catalysts.

[0053] 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.

[0054] Preferably, based on the theoretical yield of the polyester, the amount of diol having the structure shown in structural unit a is less than or equal to 200 ppm, the amount of attapulgite is 1000-30000 ppm, the amount of catalyst (in metals) is 5-300 ppm, and the amount of phosphorus-containing stabilizer is 10-100 ppm.

[0055] 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.

[0056] Preferably, the dicarboxylic acid monomer is a dicarboxylic acid having the structure shown in formula (II), and the diol monomer is a diol having the structure shown in formula (III);

[0057]

[0058] -OR A -O- Equation (III),

[0059] R1 represents a C1-C4 methyl group, y is a natural number between 0 and 4, R A It is a C2-C6 alkylene group.

[0060] A fourth aspect of this invention provides an application of the aforementioned aliphatic aromatic polyester in the preparation of sheet materials. The aforementioned aliphatic aromatic polyester possesses high impact strength and Shore hardness, making it well-suited for sheet material preparation. It can replace materials such as PS, PVC, and PC in applications including microwave oven appliances, shaped plastic parts, automotive parts, building decoration materials, and packaging for electronic and electrical products.

[0061] According to a particularly preferred embodiment of the present invention, an aliphatic aromatic polyester is provided, the polyester containing attapulgite, structural unit a of formula (I), structural unit b of formula (II), and structural unit c of formula (III).

[0062]

[0063] -OR A -O- Equation (III),

[0064] Among them, R I and R III It is a C1-C4 alkylene group, R II and RIV Each is independently C1-C4 alkyl or hydrogen, R I and R III The setup is symmetrical, where m, n, and x are all natural numbers, and m+n≤4, x+n≤4, n≥1, R1 is a C1-C4 methyl group, y is a natural number between 0 and 4, and R... A It is a C2-C6 alkylene group;

[0065] The polyester also contains a metal element, which is selected from at least one of antimony, titanium, germanium and aluminum;

[0066] In the polyester, the content of structural unit a is ≤200ppm, the content of attapulgite is 1000-30000ppm, the mass ratio of structural unit a to attapulgite is 1:5-200, and the content of the metal element is 5-300ppm.

[0067] The present invention will be described in detail below through examples. In the following examples, the melting and crystallization temperature (T) of the polyester is... mc ) and cold crystallization temperature (T c The intrinsic viscosity was calculated based on differential scanning calorimetry (DSC) testing, and was tested according to method 5.1 of GB / T14190-2017 "Test Method for Fiber Grade Polyester Chips". The DSC testing procedure 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 lowering the temperature 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 lowering the temperature to 100℃ at a rate of 10℃ / min.

[0068] The intrinsic viscosity was obtained according to GB / T14190-2017; the impact strength was tested according to GB / T17037.1-2019 by injection molding standard specimens of 80mm×10mm×4mm size with a 1mm notch; the Shore hardness was obtained according to GB / T2411-2008. Attapulgite raw material was a commercially available product from Hebei Runri Mineral Products Co., Ltd., and sodium bicarbonate was also a commercially available product.

[0069] Example 1

[0070] (1) 69.4g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 1kg of water, stirred and dispersed, and then 1g 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.

[0071] (2) Add 60 kg of terephthalic acid, 32 kg of ethylene glycol, 3.47 g of 1,8-bis(hydroxymethyl)naphthalene, the above-mentioned attapulgite aqueous dispersion, 24.1 g of antimony glycolate, and 3.873 g of phosphoric acid to a 150 L reactor. Perform esterification at 250 °C and 0.25 MPa gauge pressure. Once the water output reaches the theoretical value, end the esterification, release the pressure to atmospheric pressure, and raise the temperature for approximately 45 min until it reaches above 270 °C, entering the high-vacuum polycondensation stage. Control the polycondensation temperature at 280 °C, maintain a vacuum <100 Pa, and discharge the material after the stirring current reaches the rated value. Cool and granulate the melt to obtain the polyester base material for the sheet. Perform sufficient pre-crystallization at 130 °C, then raise the temperature to 220 °C for a solid-phase thickening reaction to obtain the finished polyester sheet.

[0072] Example 2

[0073] (1) 138.8g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 800g of water, stirred and dispersed, and then 1.5g of polyethylene glycol with a molecular weight of 400 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 30min and set aside. The dispersion was stored stably for 24 hours without separation.

[0074] (2) 60 kg of terephthalic acid, 32 kg of ethylene glycol, 6.94 g of 1,8-bis(hydroxymethyl)naphthalene, the above-mentioned attapulgite aqueous dispersion, 5.918 g of tetrabutyl titanate, and 16.3 g of triethyl phosphate were added to a 150 L reactor. Esterification was carried out at 240 °C and 0.25 MPa gauge pressure. Esterification was stopped when the water output reached the theoretical value, and the pressure was released to atmospheric pressure. The temperature was raised for about 45 minutes until it reached above 270 °C, entering the high-vacuum polycondensation stage. The polycondensation temperature was controlled at 270 °C, the vacuum was <100 Pa, and the stirring current reached the rated value before discharge. The melt was cooled and granulated to obtain the polyester base material for the sheet. The base material was fully pre-crystallized at 130 °C, and then heated to 220 °C for a solid-phase thickening reaction to obtain the finished polyester sheet.

[0075] Example 3

[0076] (1) 2082g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 10kg of water, stirred and dispersed, and then 20g of polyethylene glycol with a molecular weight of 400 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 30min and set aside. The dispersion was stored stably for 24 hours without separation.

[0077] (2) 60 kg of terephthalic acid, 32 kg of ethylene glycol, 13.88 g of 1,8-bis(hydroxymethyl)naphthalene, the above-mentioned attapulgite aqueous dispersion, 30.14 g of antimony glycolate, and 9.408 g of trimethyl phosphate were added to a 150 L reactor. Esterification was carried out at 260 °C and a gauge pressure of 0.25 MPa. Esterification was stopped when the water output reached the theoretical value, and the pressure was released to atmospheric pressure. The temperature was raised for about 45 minutes until it reached above 270 °C, entering the high-vacuum polycondensation stage. The polycondensation temperature was controlled at 285 °C, the vacuum was <100 Pa, and the stirring current reached the rated value before discharge. The melt was cooled and granulated to obtain the polyester base material for the sheet. The base material was fully pre-crystallized at 130 °C, and then heated to 220 °C for a solid-phase thickening reaction to obtain the finished polyester sheet.

[0078] Example 4

[0079] (1) 694g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 6kg of water, stirred and dispersed, and then 7g of polyethylene glycol with a molecular weight of 200 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 30min and set aside. The dispersion was stored stably for 24 hours without separation.

[0080] (2) 60 kg of terephthalic acid, 32 kg of ethylene glycol, 0.694 g of 1,8-bis(hydroxymethyl)naphthalene, the above-mentioned attapulgite aqueous dispersion, 17.35 g of germanium oxide, and 21.915 g of triphenyl phosphate were added to a 150 L reactor. Esterification was carried out at 250 °C and 0.25 MPa gauge pressure. When the water output reached the theoretical value, esterification was stopped, the pressure was released to atmospheric pressure, and the temperature was raised for about 45 min until it reached above 270 °C, entering the high-vacuum polycondensation stage. The polycondensation temperature was controlled at 280 °C, the vacuum was <100 Pa, and the stirring current reached the rated value before discharge. The melt was cooled and granulated to obtain the polyester base material for the sheet. The base material was fully pre-crystallized at 130 °C, and then heated to 220 °C for solid-phase thickening reaction to obtain the finished polyester sheet.

[0081] Example 5

[0082] (1) 69.4g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 600g of water, stirred and dispersed, and then 1g of polyethylene glycol with a molecular weight of 400 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 30min and stored for later use. The dispersion was stable for 24 hours without separation.

[0083] (2) In a 150L reactor, add 60kg of terephthalic acid, 32kg of ethylene glycol, 0.139g of 1,8-bis(hydroxymethyl)naphthalene, the above-mentioned attapulgite aqueous dispersion, 24.97g of antimony trioxide, and 5.164g of phosphoric acid. Esterification is carried out at 240℃ and 0.25MPa gauge pressure. After the water output reaches the theoretical value, esterification is stopped, the pressure is released to atmospheric pressure, and the temperature is raised for about 45 minutes to above 270℃, entering the high-vacuum polycondensation stage. The polycondensation temperature is controlled at 270℃, the vacuum is <100Pa, and the stirring current reaches the rated value before discharge. The melt is cooled and granulated to obtain the polyester base material for the sheet. The base material is fully pre-crystallized at 130℃, and then heated to 220℃ for a solid-phase thickening reaction to obtain the finished polyester sheet.

[0084] Example 6

[0085] The polyester sheet product was prepared according to the method described in Example 2, except that...

[0086] The step (1) includes: adding 444.2g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) to 2560g of water, stirring and dispersing, then adding 4.8g of polyethylene glycol with a molecular weight of 400, stirring thoroughly and then ultrasonically dispersing for 30min for later use, and storing the dispersion stably for 24 hours without separation.

[0087] In step (2), the amount of 1,8-bis(hydroxymethyl)naphthalene is 5.55g.

[0088] Example 7

[0089] The polyester sheet product was prepared according to the method described in Example 3, except that...

[0090] Step (1) includes: 1388g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) is added to 6.7kg of water, stirred and dispersed, then 13.3g of polyethylene glycol with a molecular weight of 400 is added, stirred thoroughly and ultrasonically dispersed for 30min for later use, and the dispersion is stored stably for 24 hours without separation.

[0091] In step (2), the amount of 1,8-bis(hydroxymethyl)naphthalene used is 6.94g.

[0092] Example 8

[0093] The polyester sheet product was prepared according to the method described in Example 2, except that...

[0094] The step (1) includes: adding 69.4g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) to 400g of water, stirring and dispersing, then adding 0.75g of polyethylene glycol with a molecular weight of 400, stirring thoroughly and then ultrasonically dispersing for 30min for later use, and storing the dispersion stably for 24 hours without separation.

[0095] In step (2), the amount of 1,8-bis(hydroxymethyl)naphthalene is 13.88 g.

[0096] Example 9

[0097] The polyester sheet product was prepared according to the method described in Example 3, except that...

[0098] Step (1) includes: adding 2602.5g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) to 12.5kg of water, stirring and dispersing, then adding 25g of polyethylene glycol with a molecular weight of 400, stirring thoroughly and then ultrasonically dispersing for 30min for later use, and storing the dispersion stably for 24 hours without separation.

[0099] In step (2), the amount of 1,8-bis(hydroxymethyl)naphthalene is 17.35 g.

[0100] Example 10

[0101] 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.

[0102] Example 11

[0103] 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.

[0104] Example 12

[0105] Modified polyester chips were prepared according to the method described in Example 1, except that the length of the attapulgite was 10 μm and the diameter was 80 nm.

[0106] Comparative Example 1

[0107] In a 150L reactor, 60kg of terephthalic acid, 32kg of ethylene glycol, 30.14g of antimony glycolate, and 9.408g of trimethyl phosphate were added. Esterification was carried out at 260℃ and a gauge pressure of 0.25MPa. Once the water output reached the theoretical value, esterification was terminated, and the pressure was released to atmospheric pressure. The temperature was then raised to above 270℃ for approximately 45 minutes, entering a high-vacuum polycondensation stage. The polycondensation temperature was controlled at 285℃, the vacuum was <100Pa, and the stirring current reached the rated value before discharge. The melt was cooled and granulated to obtain the polyester base material for the sheet. The base material underwent thorough pre-crystallization at 130℃, followed by a solid-phase thickening reaction at 220℃ to obtain the finished polyester sheet.

[0108] Comparative Example 2

[0109] In a 150L reactor, 60kg of terephthalic acid, 32kg of ethylene glycol, 13.88g of 1,8-bis(hydroxymethyl)naphthalene, 30.14g of antimony glycolate, and 9.408g of trimethyl phosphate were added. Esterification was carried out at 260℃ and 0.25MPa gauge pressure. Once the water output reached the theoretical value, esterification was terminated, the pressure was released to atmospheric pressure, and the temperature was raised for approximately 45 minutes until it reached above 270℃, entering the high-vacuum polycondensation stage. The polycondensation temperature was controlled at 285℃, the vacuum was <100Pa, and the stirring current reached the rated value before discharge. The melt was cooled and granulated to obtain the polyester base material for the sheet. The base material underwent sufficient pre-crystallization at 130℃, and then the temperature was raised to 220℃ for a solid-phase thickening reaction to obtain the finished polyester sheet.

[0110] Comparative Example 3

[0111] (1) 2082g of commercially available purified attapulgite clay (length less than 3μm, diameter less than 50nm) was added to 10kg of water, stirred and dispersed, and then 20g of polyethylene glycol with a molecular weight of 400 was added. After stirring thoroughly, the mixture was ultrasonically dispersed for 30min and set aside. The dispersion was stored stably for 24 hours without separation.

[0112] (2) 60 kg of terephthalic acid, 32 kg of ethylene glycol, the above-mentioned attapulgite aqueous dispersion, 30.14 g of antimony glycolate, and 9.408 g of trimethyl phosphate were added to a 150 L reactor. Esterification was carried out at 260 °C and 0.25 MPa. When the water output reached the theoretical value, esterification was stopped, the pressure was released to atmospheric pressure, and the temperature was raised to above 270 °C for about 45 min, entering the high-vacuum polycondensation stage. The polycondensation temperature was controlled at 285 °C, the vacuum was <100 Pa, and the stirring current reached the rated value before discharge. The melt was cooled and granulated to obtain the polyester base material for the sheet. The base material was fully pre-crystallized at 130 °C, and then heated to 220 °C for solid-phase thickening reaction to obtain the finished polyester sheet.

[0113] Comparative Example 4

[0114] Modified polyester chips were prepared according to the method described in Example 3, except that 1,8-bis(hydroxymethyl)naphthalene was replaced with sodium benzoate.

[0115] Comparative Example 5

[0116] Modified polyester chips were prepared according to the method described in Example 3, except that attapulgite was replaced with sodium bicarbonate.

[0117] Test Example 1

[0118] The parameters of the polyester material are shown in Table 1. Performance indicators were tested according to the national standard GB / T14189-2008, "Test Method for Fiber Grade Polyester Chips," and are shown in Table 2. The polyester composition was injection molded into standard specimens of 80mm × 10mm × 4mm with a 1mm notch, according to the national standard GB / T17037.1-2019. Hardness and impact strength were measured on these specimens, and the data are shown in Table 2.

[0119] Table 1

[0120]

[0121]

[0122] Table 2

[0123]

[0124] As can be seen from the results in Tables 1 and 2, the impact strength and Shore hardness of the sheet prepared in the embodiments of the present invention are higher than those of the sheet in the comparative example, indicating that the nucleation system provided by the present invention can effectively improve the impact strength and Shore hardness of the obtained polyester.

[0125] 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 nucleation system, characterized in that, The nucleation system contains nucleating agent A and nucleating agent B, which are either stored together or stored independently. Nucleating agent A contains a naphthalene ring structure and a C1-C4 alkyl group substituted with a hydroxyl group attached to the naphthalene ring structure. Nucleating agent B is attapulgite.

2. The nucleation system according to claim 1, characterized in that, In the naphthalene ring structure, there are an even number of hydroxyl-substituted C1-C4 alkyl groups, and the even number of hydroxyl-substituted C1-C4 alkyl groups are symmetrically connected in the naphthalene ring structure; Preferably, the structure of the nucleating agent A is as shown in formula (I). 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 nucleation system according to claim 1 or 2, characterized in that, The mass ratio of nucleating agent A to nucleating agent B is 1:5-200, preferably 1:20-150; preferably, the length of the attapulgite soil is ≤3μm and the diameter is ≤50nm.

4. The application of the nucleation system according to any one of claims 1 to 2 in polyester; Preferably, the polyester is an aliphatic aromatic polyester; Preferably, the polyester is polyethylene terephthalate.

5. An aliphatic aromatic polyester, characterized in that, The polyester contains attapulgite and structural unit a, wherein structural unit a contains a naphthalene ring structure and C1-C4 alkylene groups connected to the naphthalene ring structure, and the C1-C4 alkylene groups are connected to the naphthalene ring structure via C-C bonds.

6. The aliphatic aromatic polyester according to claim 5, 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 (I). 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.

7. The aliphatic aromatic polyester according to claim 5 or 6, characterized in that, In the polyester, the content of structural unit a is 1-200 ppm, and the content of attapulgite is 1000-30000 ppm; Preferably, the mass ratio of the structural unit a to the attapulgite soil is 1:5-200, and more preferably 1:20-150; Preferably, the polyester further contains a metal element selected from at least one of antimony, titanium, germanium, and aluminum; Preferably, the content of the metal element in the polyester is 5-300 ppm.

8. The aliphatic aromatic polyester according to claim 5 or 6, characterized in that, The polyester also contains structural unit b as shown in formula (II) and structural unit c as shown in formula (III); -O-R A -O-formula (III), Where R1 is a C1-C4 methyl group, y is a natural number between 0 and 4, and R A It is a C2-C6 alkylene group; Preferably, in formula (II), y is 0, and the two carbonyl groups on the benzene ring structure are arranged in a para or meta position.

9. The aliphatic aromatic polyester according to claim 5 or 6, characterized in that, The polyester has a melt crystallization temperature of 188-202℃, a cold crystallization temperature of 120-132℃, and an impact strength of 65-80 J·m. -1 Its Shore hardness is 77-85D.

10. The use of the aliphatic aromatic polyester according to any one of claims 5 to 9 in sheet materials.

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