Aromatic polyester containing cyclic imide structure

Abstract

According to the aromatic polyester containing the cyclic imide structure, a cyclic imide side group or side chain is introduced into the aromatic polyester through a diacid monomer or a diol monomer, so that the defects that the aromatic polyester is low in mechanical strength and poor in film-forming supporting performance are overcome; by introducing an imide structure, the polarity of the polymer is improved, and the rear-end blending modification capability is improved, so that the comprehensive mechanical property of a polyester product is improved.

Description

[0001] The invention belongs to the field of polymer materials, and in particular relates to an aromatic polyester containing a cyclic imide structure. Background Art

[0002] Long-chain aromatic polyesters, such as polybutylene terephthalate (PBAT), are petroleum-based biodegradable materials with excellent ductility and high elongation at break. They are widely used in the preparation of film and bag products such as degradable ground films, express packaging, and shopping bags, and have broad development prospects. However, they have low crystallinity (around 30%), poor crystallinity, low mechanical strength, especially tensile strength (around 20 MPa), and poor tear resistance, making them difficult to use alone. They often need to be blended with other polymers to improve their mechanical properties. Furthermore, due to the low relative molar content of ester bonds in the aromatic polyester chain structure, their polarity is poor, resulting in relatively poor blending performance with aromatic polyesters.

[0003] Therefore, by adjusting the main chain chemical structure to improve the mechanical properties of aromatic polyesters, the mechanical properties of aromatic polyesters are fundamentally improved, and the properties of their blends with other polymers, such as compatibility, are also improved. Summary of the Invention

[0004] In view of this, the present invention provides the following technical solutions:

[0005] In a first aspect, the present invention provides an aromatic polyester containing a cyclic imide structure, wherein the aromatic polyester containing a cyclic imide structure comprises a main aromatic polyester structural unit containing a benzene ring and a modification unit, wherein the main aromatic polyester structural unit containing a benzene ring comprises a polyester unit obtained by polymerizing a diol used for polymer synthesis with a dibasic acid / anhydride / ester containing a benzene ring; and the modification unit comprises a first modification unit and / or a second modification unit, wherein the first modification unit comprises a structure of formula (I):

[0006]

[0007] R1 is selected from an alkylene group having 1 to 7 carbon atoms, preferably a straight or branched alkylene group having 1, 2, 3 or 4 carbon atoms in the main chain, an arylene group having 6 to 12 carbon atoms, a heteroarylene group having 5 to 11 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, a heterocycloalkylene group having 2 to 11 carbon atoms or a combination thereof, optionally containing the following substituents: halogen, nitro, C1-C4 alkyl, halogenated C1-C4 alkyl, C6-C 12 Aryl, C6-C 12 Aryl-C1-C4 alkyl or halogenated, C1-C4 alkyl substituted C6-C 12 Aryl or C6-C 12 Aryl-C1-C4 alkyl;

[0008] R2 is selected from a linear alkylene group having 2 to 12 carbon atoms, a branched alkylene group having 3 to 12 carbon atoms, an arylene group having 6 to 12 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, or a trivalent C1-C5 alkyl-C6-C8 aryl-C1-C5 alkyl group, optionally containing the following substituents: halogen, nitro, C1-C4 alkyl, halogenated C1-C4 alkyl, C6-C8 alkyl, C1-C5 ... 12 Aryl, C6-C 12 Aryl-C1-C4 alkyl or halogenated, C1-C4 alkyl substituted C6-C 12 Aryl or C6-C 12 Aryl-C1-C4 alkyl;

[0009] The second modifying unit comprises a structure of formula (II):

[0010]

[0011] Wherein Asp is the residue of aspartic acid;

[0012] X is selected from an alkylene group having 1 to 7 carbon atoms, preferably a linear or branched alkylene group having 1, 2, 3 or 4 carbon atoms in the main chain, an arylene group having 6 to 12 carbon atoms, a heteroarylene group having 5 to 11 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, a heterocycloalkylene group having 2 to 11 carbon atoms or a combination thereof, optionally containing the following substituents: halogen, nitro, C1-C4 alkyl, halogenated C1-C4 alkyl, C6-C 12 Aryl, C6-C 12 Aryl-C1-C4 alkyl or halogenated, C1-C4 alkyl substituted C6-C 12 Aryl or C6-C 12 Aryl-C1-C4 alkyl;

[0013] n is an integer of 0 or greater; preferably, when n is greater than 0, the content of the second modifying unit is greater than 0.

[0014] In a specific embodiment of the present invention, the aromatic polyester containing a cyclic imide structure of the present invention, wherein the structure of the first modifying unit is:

[0015]

[0016] wherein R3 is a C2-C4 straight-chain or branched alkylene group, 1,4-cyclohexylene group or 1,4-phenylene group, and * indicates the connection position with other units.

[0017] Preferably, R2 is the residue of 2-amino-1,3-propanediol or 3-amino-1,2-propanediol.

[0018] Preferably, R1 is a succinic acid residue (ie, ethylene).

[0019] Preferably, R3 is a succinic acid residue.

[0020] In a specific embodiment of the present invention, in the aromatic polyester containing a cyclic imide structure of the present invention, the first modified unit accounts for 1-50 mol%, preferably 5-50 mol%, of the total structural units in the aromatic polyester containing a cyclic imide structure.

[0021] In a specific embodiment of the present invention, the structure of the second modification unit in the aromatic polyester containing a cyclic imide structure of the present invention is:

[0022]

[0023] Wherein Asp is an aspartic acid residue, X is ethylene, 1,2-cyclohexylene or 1,2-phenylene, R4 is a diol residue used for polymer synthesis and comprises a butanediol residue, preferably a 1,4-butanediol residue, or a combination of a 1,4-butanediol residue and a propylene glycol or ethylene glycol residue, * indicates the connection position with other units; n is an integer of 0 or greater; preferably, when n is greater than 0, the content of the second modifying unit is greater than 0;

[0024] Preferably, X is ethylene; preferably, R4 is ethylene.

[0025] In a specific embodiment of the present invention, the second modified structural unit in the aromatic polyester containing a cyclic imide structure of the present invention accounts for 0.5-99.5 mol%, preferably 1-90 mol%, and more preferably 5%-50 mol% of the total structural units in the aromatic polyester containing a cyclic imide structure.

[0026] In a specific embodiment of the present invention, the aromatic polyester containing a cyclic imide structure of the present invention comprises a first modification unit and a second modification unit respectively or simultaneously. Preferably, the aromatic polyester containing a cyclic imide structure further comprises a third modification structure unit.

[0027] In a second aspect, the present invention provides a polymer alloy comprising any of the aforementioned aromatic polyesters containing a cyclic imide structure.

[0028] In a third aspect, the present invention provides a polymer composition or a molded article comprising any of the aforementioned aromatic polyesters containing a cyclic imide structure.

[0029] In a fourth aspect, the present invention provides uses of any of the aforementioned aromatic polyesters, or polymer alloys, or polymer compositions, or molded bodies containing a cyclic imide structure, the uses including use in food containers, food packaging films, disposable tableware such as spoons or straws, packaging containers such as transparent boxes for daily necessities, cosmetics, and household appliances, transparent windows for cartons, transparent folders, stationery such as ID holders, industrial films or agricultural films, and chemical fibers for clothing or industry.

[0030] In a fifth aspect, the present invention provides a method for preparing the aromatic polyester containing a cyclic imide structure, comprising:

[0031] 1) Provide:

[0032] The diol monomer represented by formula V is:

[0033]

[0034] Wherein: R1 and R2 are as defined above;

[0035] or / and

[0036] Aspartic acid monomer represented by formula VI:

[0037]

[0038] Wherein Asp is an aspartic acid residue, X is defined as described in any one of claims 1 to 6, and n is an integer of 0 or greater than 0; preferably, when n is greater than 0, the content of the second modified unit is greater than 0;

[0039] 2) subjecting the diol monomer or / and aspartic acid monomer, a benzene ring-containing dibasic acid / ester / alcohol / anhydride, optionally another one or more dibasic acids / esters / anhydrides used for polymer synthesis, and a diol used for polymer synthesis to an esterification / transesterification reaction, or subjecting the diol monomer or / and aspartic acid monomer to an esterification / transesterification reaction with a prepolymer to obtain an aromatic polyester containing a cyclic imide structure and comprising a first modifying unit or / and a second modifying unit, wherein the prepolymer is obtained by subjecting the dibasic acid / ester / anhydride containing a benzene ring, optionally another one or more dibasic acids / esters / anhydrides used for polymer synthesis, and a diol used for polymer synthesis to an esterification / transesterification reaction. DETAILED DESCRIPTION

[0040] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without one or more of these details. In other instances, certain technical features well known in the art are not described to avoid confusion with the present invention.

[0041] Unless otherwise specified, the percentages or usage ratios in the present invention are all molar ratios.

[0042] The following describes the implementation of the present invention in detail with reference to the definitions of terms:

[0043] I Aromatic polyester containing a cyclic imide structure comprising a first modifying unit

[0044] The synthesis method of the aromatic polyester containing a cyclic imide structure and comprising the first modification unit can refer to the Chinese patent application (CN202311583766.2), including:

[0045] Step 1: A primary amino diol (such as 2-amino-1,3-propanediol or 3-amino-1,2-propanediol) is subjected to an amidation reaction with a readily cyclic dibasic acid (such as succinic acid or glutaric acid) and / or its corresponding acid anhydride to obtain a monomer composition; the monomer composition includes a diol monomer containing an imide ring structure as shown in formula (V):

[0046]

[0047] Wherein: R1 is independently selected from an alkylene group having 1 to 7 carbon atoms, preferably a straight or branched alkylene group having 1, 2, 3 or 4 carbon atoms in the main chain, an arylene group having 6 to 12 carbon atoms, a heteroalkylene group having 5 to 11 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, a heterocycloalkylene group having 2 to 11 carbon atoms or a combination thereof, optionally containing the following substituents: halogen, nitro, C1-C4 alkyl, halogenated C1-C4 alkyl, C6-C 12 Aryl, C6-C 12 Aryl-C1-C4 alkyl or halogenated, C1-C4 alkyl substituted C6-C 12 Aryl or C6-C 12 Aryl-C1-C4 alkyl;

[0048] R2 is selected from a linear alkylene group having 2 to 12 carbon atoms, a branched alkylene group having 3 to 12 carbon atoms, an arylene group having 6 to 12 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, or a trivalent C1-C5 alkyl-C6-C8 aryl-C1-C5 alkyl group, optionally containing the following substituents: halogen, nitro, C1-C4 alkyl, halogenated C1-C4 alkyl, C6-C8 alkyl, C1-C5 ... 12 Aryl, C6-C 12 Aryl-C1-C4 alkyl or halogenated, C1-C4 alkyl substituted C6-C 12 Aryl or C6-C 12 Aryl-C1-C4 alkyl.

[0049] The typical preparation process includes:

[0050] 911.1 g (10 mol) of 2-amino-1,3-propanediol and 1180.1 g (10 mol) of 1,4-butanedioic acid after vacuum drying were put into a reactor, and 100 ppm each of triphenyl phosphite (thermal stabilizer) and tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentylerythritol ester (antioxidant) were added (compared to the weight of the entire reaction system, the same below) and stirred at room temperature. At the same time, nitrogen was used to fully replace the air in the reactor. Then, the temperature was slowly raised to 120° C. in a nitrogen atmosphere, the nitrogen flow rate was 150 mL / min, and the mixture was stirred at a constant temperature for 3 hours to obtain a diol monomer composition.

[0051] Representative diol monomers include:

[0052]

[0053] Step 2: subjecting the diol monomer composition, a benzene ring-containing dibasic acid / ester / anhydride, optionally one or more other dibasic acids / esters / anhydrides used for polymer synthesis, and a diol used for polymer synthesis to an esterification / transesterification reaction, or subjecting the diol monomer composition to an esterification / transesterification reaction with a prepolymer to obtain an aromatic polyester containing a cyclic imide structure and comprising a first modification unit, wherein the prepolymer is obtained by subjecting a benzene ring-containing dibasic acid / ester / anhydride, optionally one or more other dibasic acids / esters / anhydrides used for polymer synthesis, and a diol used for polymer synthesis to an esterification / transesterification reaction to obtain an aromatic polyester containing a cyclic imide structure and comprising a first modification unit, wherein the structure of the diol monomer containing an imide ring structure and the dibasic acid polymerized is:

[0054] R3 is a dibasic acid used for polymer synthesis or a dibasic acid residue that is easily cyclic, or a combination of the two. In a specific embodiment of the present invention, R3 is a dibasic acid residue used for polymer synthesis, preferably a combination of a terephthalic acid residue and / or a succinic acid residue, an adipic acid residue, a sebacic acid residue or azelaic acid residue.

[0055] In one embodiment, the first modification unit accounts for 1-50 mol% of the total structural units in the aromatic polyester containing a cyclic imide structure, preferably 5-50 mol%, for example, 5%, 10%, 20%, 30%, 40%, or 50%.

[0056] II Aromatic polyester containing a cyclic imide structure comprising a second modifying unit

[0057] The synthesis of the aromatic polyester containing a cyclic imide structure and comprising a second modified unit can refer to Chinese patent application (CN202311738254.9), including:

[0058] Step 1: Synthesis of aspartic acid monomer containing an imide ring structure:

[0059] The monomer can be obtained by mixing aspartic acid and a dicarboxylic acid that is easy to form a ring in a certain proportion and performing an amidation reaction. The reaction conditions can be selected by those skilled in the art according to the aspartic acid and the dicarboxylic acid that is easy to form a ring, for example, reacting under anaerobic hot melt conditions.

[0060] A typical preparation process involves reacting aspartic acid and succinic acid in a 1:3 molar ratio in a reactor, adding 200 ppm of an antioxidant and a heat stabilizer, and heating and melting the mixture under nitrogen protection to react. Another example involves reacting aspartic acid and 1,2-cyclohexanedicarboxylic acid in a 1:3 molar ratio in a reactor, adding 200 ppm of an antioxidant and a heat stabilizer, and heating and melting the mixture under nitrogen protection to react, to obtain an aspartic acid monomer containing an imide heterocycle:

[0061]

[0062] Representative monomers include:

[0063]

[0064]

[0065] Step 2: subjecting the aspartic acid monomer, the benzene ring-containing dibasic acid / ester / anhydride, optionally one or more other dibasic acids / esters / anhydrides used for polymer synthesis, and a diol used for polymer synthesis to an esterification / transesterification reaction, or subjecting the aspartic acid monomer and a prepolymer to an esterification / transesterification reaction, to obtain an aromatic polyester containing a cyclic imide structure and comprising a second modified unit, wherein the prepolymer is obtained by subjecting the benzene ring-containing dibasic acid / ester / anhydride, optionally one or more other dibasic acids / esters / anhydrides used for polymer synthesis, and a diol used for polymer synthesis to an esterification / transesterification reaction, wherein the structure of the aspartic acid monomer containing an imide ring structure and the diol polymerized is:

[0066]

[0067] Wherein Asp is an aspartic acid residue, X is preferably ethylene, 1,2-cyclohexylene, or 1,2-phenylene, and R4 is a diol residue used for polymer synthesis, preferably a butanediol residue, or a combination of a butanediol residue and a propylene glycol or ethylene glycol residue. n is an integer of 0 or greater; preferably, if n is greater than 0, the content of the second modifying unit is greater than 0; preferably, the average value of n is less than 2, and more preferably less than 1.

[0068] In one embodiment, the second modified structural unit accounts for 0.5-99.5 mol% of the total structural units in the aromatic polyester containing a cyclic imide structure, preferably 1-90 mol%, and more preferably 5%-50 mol%, for example, it can be 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%.

[0069] III. Polymer containing a third modified structural unit

[0070] The polymer of the present invention may optionally include a third modification unit that is heat-resistant, transparent or has a high barrier property. The third modification unit may be a dibasic acid (succinic acid, 2-methylsuccinic acid, 2-phenylsuccinic acid, 2-benzylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, 2,3-diphenylsuccinic acid, 1,2-cyclobutanediol, 2,2,3,3-tetramethylsuccinic acid, oxalic acid, malonic acid, 1,6-hexanedioic acid, 1,10-decanedioic acid, 1,18-octadecanediol, maleic acid, methylmaleic acid, dimethylmaleic acid, phthalic acid, hexahydrophthalic acid, norbornene dicarboxylic acid, tetrahydrophthal ... The invention is composed of at least one of phthalic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 3-phenylglutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylglutaric acid, diglycolic acid, 2,3-furandicarboxylic acid, 3,4-furandicarboxylic acid, 2,3-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid, terephthalic acid, and 2,5-furandicarboxylic acid) or a polymerization repeating unit composed of a diamine or an amino acid (one or more of isophthalic acid, furandicarboxylic acid, camphoric acid, adipic acid, proline, and meta-xylenediamine) and a diol (one or more of ethylene glycol, butanediol, and 1,4-cyclohexanedimethanol).

[0071] In one embodiment, the content of the above-mentioned dibasic acid, diamine or diol in the final aromatic polyester containing a cyclic imide structure can be any value or 0.1-99%, for example, it can be 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%.

[0072] IV Aromatic polyester containing a cyclic imide structure comprising a modified unit

[0073] The aromatic polyester of the present invention comprises a main structural unit of an aromatic polyester containing a benzene ring, wherein the main structural unit of the aromatic polyester containing a benzene ring comprises a polyester unit obtained by polymerizing a diol used for polymer synthesis with a dibasic acid / anhydride / ester containing a benzene ring; the aromatic polyester of the present invention further comprises a polyester unit obtained by polymerizing a diol used for polymer synthesis with one or more other dibasic acids / anhydrides / esters used for polymer synthesis, such as aliphatic dibasic acids / anhydrides / esters. The aromatic polyester is further preferably a polyester based on aliphatic and aromatic dicarboxylic acids and aliphatic dihydroxy compounds, including but not limited to poly(butylene adipate terephthalate) (PBAT), poly(butylene sebacate terephthalate) (PBSeT), poly(butylene azelaic terephthalate) (PBAzT), or poly(butylene succinate terephthalate) (PBST).

[0074] The method for preparing the aromatic polyester containing a cyclic imide structure and comprising a modified unit according to the present invention comprises:

[0075] 1) Provide:

[0076] The diol monomer represented by formula V is:

[0077]

[0078] Wherein: R1 and R2 are as defined above;

[0079] or / and

[0080] Aspartic acid monomer represented by formula VI:

[0081]

[0082] Wherein Asp is an aspartic acid residue, X is as defined above, and n is an integer of 0 or greater than 0; preferably, the content of the second modified unit where n is greater than 0 is greater than 0;

[0083] 2) subjecting the diol monomer or / and aspartic acid monomer, a benzene ring-containing dibasic acid / ester / alcohol / anhydride and optionally one or more other dibasic acids and diols / esters / anhydrides used for polymer synthesis to an esterification / transesterification reaction, or subjecting the diol monomer or / and aspartic acid monomer to an esterification / transesterification reaction with a prepolymer to obtain an aromatic polyester containing a cyclic imide structure and comprising a first modifying unit or / and a second modifying unit, wherein the prepolymer is obtained by subjecting the dibasic acid / ester / anhydride containing a benzene ring, optionally one or more other dibasic acids / esters / anhydrides used for polymer synthesis to an esterification / transesterification reaction with a diol used for polymer synthesis.

[0084] V alloy

[0085] The polymers of the present invention may form alloys with each other or optionally with other polymers.

[0086] VI Composition and Molded Article

[0087] The present invention also provides a composition or a molded body of the above polymer. Methods for processing or molding various types of polymers are known in the art.

[0088] The aromatic polyester composition containing a cyclic imide structure in the present invention may further contain a plasticizer, a crystal nucleating agent or a hydrolysis inhibitor.

[0089] The aromatic polyester composition containing a cyclic imide structure of the present invention may contain, as other ingredients besides those mentioned above, fillers (inorganic fillers, organic fillers), flame retardants, antioxidants, hydrocarbon waxes or anionic surfactants (i.e., lubricants), ultraviolet absorbers, antistatic agents, anti-corona agents, light stabilizers, pigments, mildewproofing agents, antibacterial agents, and foaming agents, within the range that does not impair the effects of the present invention. Similarly, other polymer materials and other resin compositions may be added within the range that does not impair the effects of the present invention.

[0090] The aromatic polyester composition containing a cyclic imide structure of the present invention can be prepared into a molded body such as a sheet by extrusion molding or press molding; the obtained sheet can also be further thermoformed within a temperature range above the glass transition temperature (Tg) and below the melting point (Tm) of the aromatic polyester composition containing a cyclic imide structure, for example, stretched into a film or fiber.

[0091] VII Products and Uses

[0092] The polymer, alloy thereof, or composition or molded article of the present invention is suitable for use in food containers, food packaging films, disposable tableware such as spoons or straws, transparent boxes for daily necessities, cosmetics, home appliances, etc., transparent windows for cardboard boxes, etc., transparent folders, ID holders and other stationery, industrial films or agricultural films, and chemical fibers for clothing or industry.

[0093] Amino-containing diols

[0094] The amino-containing diol in the present invention has the following structure: HO-R2(NH2)-OH. The amino-containing diol can be selected from an alkanediolamine that is unsubstituted or substituted with a substituent selected from a halogen, alkyl, or nitro group, or an alkyl-aryl-alkanediolamine that is unsubstituted or substituted with a substituent selected from a halogen, alkyl, or nitro group. Preferably, the amino-containing diol can be selected from at least one of 3-amino-1,2-propylene glycol, 2-amino-1,3-propylene glycol, 2-amino-1,3-butanediol, 2-amino-1,4-butanediol, 2-amino-1,5-pentanediol, 3-amino-1,5-pentanediol, 5-amino-1,3-benzenedimethanol, and 2-amino-1,3-phenylenedimethanol.

[0095] Dibasic acids / esters / anhydrides containing benzene rings

[0096] The dibasic acid / ester / alcohol / anhydride containing a benzene ring of the present invention is selected from the dibasic acid / ester / alcohol / anhydride containing a benzene ring which is unsubstituted or substituted with a substituent selected from halogen, hydroxyl, alkyl, alkoxy or nitro. Examples of the dibasic acid containing a benzene ring include phthalic acid, isophthalic acid, phthalic acid, biphthalic acid, naphthalene dicarboxylic acid, etc.; examples of the dibasic acid anhydride containing a benzene ring include phthalic anhydride, isophthalic anhydride, phthalic anhydride, biphthalic anhydride, naphthalene dicarboxylic anhydride, etc.; examples of the dibasic acid containing a benzene ring include phthalic anhydride, isophthalic anhydride, phthalic anhydride, biphthalic anhydride, naphthalene dicarboxylic anhydride, etc. Examples of esters include dimethyl terephthalate, diethyl terephthalate, dipropyl terephthalate, dibutyl terephthalate, dimethyl 1,4-naphthalene dicarboxylate, diethyl 1,4-naphthalene dicarboxylate, dipropyl 1,4-naphthalene dicarboxylate, dibutyl 1,4-naphthalene dicarboxylate, 2,6-naphthalene dicarboxylate, dimethyl isophthalate, diethyl isophthalate, dipropyl isophthalate, dibutyl isophthalate, dimethyl biphenyl, diethyl biphenyl, dipropyl biphenyl and dibutyl biphenyl.

[0097] Dicarboxylic acid HOOC-R1-COOH that is easily cyclized

[0098] The HOOC-R1-COOH is a dicarboxylic acid that readily cyclizes, i.e., a dicarboxylic acid that readily forms a cyclic anhydride in the absence of a catalyst or under catalytic conditions. Dicarboxylic acids that readily cyclize are known to those skilled in the art, for example, see CN110790906B. HOOC-R1-COOH may be selected from an alkanedicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen, alkyl, aryl, arylalkyl or alkylaryl, an alkanedicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen, alkyl, aryl, arylalkyl or alkylaryl and is interrupted by one or more O atoms, an alkenedicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen or alkyl, a cycloalkanedicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen, alkyl or nitro, a cycloalkenedicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen, alkyl or nitro, an aromatic dicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen, alkyl or nitro, or a bridged cyclic dicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen, alkyl or nitro. Preferably, HOOC-R1-COOH can be selected from at least one of succinic acid, 2-methylsuccinic acid, 2-phenylsuccinic acid, 2-benzylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, 2,3-diphenylsuccinic acid, 1,2-cyclobutanedicarboxylic acid, 2,2,3,3-tetramethylsuccinic acid, methylmaleic acid, dimethylmaleic acid, phthalic acid, hexahydrophthalic acid, norbornenic acid, tetrahydrophthalic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 3-phenylglutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylglutaric acid, diglycolic acid, 2,3-furandicarboxylic acid, 3,4-furandicarboxylic acid, 2,3-pyridinedicarboxylic acid, and 3,4-pyridinedicarboxylic acid. The cyclic anhydride of HOOC-R1-COOH can be preferably selected from succinic anhydride, 2-methylsuccinic anhydride, 2-phenylbutyric anhydride, 2-benzylsuccinic anhydride, 2,2-dimethylsuccinic anhydride, 2,3-dimethylsuccinic anhydride, 2,3-diphenylsuccinic anhydride, 1,2-cyclosuccinic anhydride, 2,2,3,3-tetramethylsuccinic anhydride, methylmaleic anhydride, dimethylmaleic anhydride, phthalic anhydride At least one of dihydrophthalic anhydride, hexahydrophthalic anhydride, nadic anhydride, tetrahydrophthalic anhydride, glutaric anhydride, 2-methylglutaric anhydride, 3-methylglutaric anhydride, 3-phenylglutaric anhydride, 2,2-dimethylglutaric anhydride, 3,3-dimethylglutaric anhydride and diglycolic anhydride, 2,3-furandicarboxylic anhydride, 3,4-furandicarboxylic anhydride, 2,3-pyridinedicarboxylic anhydride and 3,4-pyridinedicarboxylic anhydride.

[0099] Dicarboxylic acids for polymer synthesis

[0100] The dicarboxylic acid used for polymer synthesis in the present invention can be used for the synthesis of polymer bulk structural units, and can also be used for the synthesis of structural units for improving polymer strength. When used for the synthesis of structural units for improving polymer strength, that is, HOOC-R3-COOH defined in the present invention, it can be any dicarboxylic acid different from HOOC-R2-COOH, for example, it can be the easily cyclized dicarboxylic acid described above for HOOC-R2-COOH; or it can be a dicarboxylic acid that is not easily cyclized, such as terephthalic acid, 2,5-furandicarboxylic acid, oxalic acid, malonic acid, 1,6-hexanediol, 1,10-decanedioic acid, and 1,18-octadecanediol. Preferably, HOOC-R3-COOH can be selected from an alkane dicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen, alkyl, aryl, arylalkyl or alkylaryl, an alkane dicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen, alkyl, aryl, arylalkyl or alkylaryl and is interrupted by one or more O atoms, an alkene dicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen or alkyl, a cycloalkane dicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen, alkyl or nitro, a cycloalkene dicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen, alkyl or nitro, an aromatic dicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen, alkyl or nitro, or a bridged cyclic dicarboxylic acid which is unsubstituted or substituted with a substituent selected from halogen, alkyl or nitro. Preferably, HOOC-R3-COOH can be selected from succinic acid, 2-methylsuccinic acid, 2-phenylsuccinic acid, 2-benzylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, 2,3-diphenylsuccinic acid, 1,2-cyclobutanediol, 2,2,3,3-tetramethylsuccinic acid, oxalic acid, malonic acid, 1,6-hexanediol, 1,10-decanedioic acid, 1,18-octadecanedioic acid, maleic acid, methylmaleic acid, dioctadecanedioic ... 1,6-hexanediol, 1,10-decanedioic acid, 1,18-octadecanedioic acid, 1,6-hexanediol, 1,10-decanedioic acid, 1,18-octadecanedioic acid, 1,6-hexanediol, 1,6-hexanediol, 1,10-decanedioic acid, 1,18-octadecanedioic acid, 1,6-hexanediol, 1,6-hexanediol, 1,10-decanedioic acid, 1,18-octadecanedioic acid, 1,6-hexanediol, 1,6-hexanediol, 1,6-hexanediol, 1,6-hexanediol, 1,6-hex At least one of methylmaleic acid, phthalic acid, hexahydrophthalic acid, norbornenic acid, tetrahydrophthalic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 3-phenylglutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylglutaric acid, diglycolic acid, 2,3-furandicarboxylic acid, 3,4-furandicarboxylic acid, 2,3-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid, terephthalic acid, and 2,5-furandicarboxylic acid.

[0101] In one embodiment, the content of the dicarboxylic acid used for polymer synthesis in the final aromatic polyester containing a cyclic imide structure can be any value or 0.1-99%, for example, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%.

[0102] Diols for polymer synthesis

[0103] The diol used for polymer synthesis can be selected from alkylene glycols that are unsubstituted or substituted with substituents selected from halogen, alkyl or nitro groups, OH-alkylene-cycloalkylene-alkylene-OH that are unsubstituted or substituted with substituents selected from halogen, alkyl or nitro groups, polyether glycols, or alkylene glycols interrupted by one or more nitrogen atoms; preferably, at least one selected from alkylene glycols containing 2 to 18 carbon atoms, polyethylene glycol, polypropylene glycol, polytetrahydrofuran diol, N-methyldiethanolamine, and N-ethyldiethanolamine. Preferably, at least one selected from ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,18-octadecanediol, polyethylene glycol, and 1,4-cyclohexanedimethanol.

[0104] In one embodiment, the content of the diol used for polymer synthesis in the final aromatic polyester containing a cyclic imide structure can be any value or 0.1-99%, for example, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%.

[0105] Polyester structural unit

[0106] The polyester structural unit used in the present invention has the common meaning in the art, and is preferably formed by polycondensation of the above-mentioned dicarboxylic acid used for polymer synthesis and diol used for polymer synthesis.

[0107] Example

[0108] The polymer synthesis formula and material properties are shown in Table 1-3.

[0109] Example 1-1 The modified unit synthesis monomers were placed in a reactor at a molar ratio of aspartic acid: succinic acid = 1:3, and 200 ppm of an antioxidant and a heat stabilizer were added. The temperature was raised and melted under nitrogen protection to react and synthesize the functional monomers. While the above functional monomers were being synthesized, 1,4-phthalic acid, 1,6-hexanedioic acid and butanediol were added to another reactor, wherein the molar ratio of each material satisfied 1,4-phthalic acid: hexanedioic acid = 9:11, (1,4-phthalic acid + hexanedioic acid): butanediol = 1:1.2, and 200 ppm of an antioxidant and a heat stabilizer were added. The temperature was raised under nitrogen protection and the reaction was maintained at 160°C for 2 hours; then the temperature was continued to be raised to 220°C and the reaction was refluxed for 3 hours.

[0110] Step 2: Blend the two kettle materials according to the molar ratio of cyclic imide segment: PBAT main chain of 1:19 (i.e., the modified unit content is 5%), heat to 200 ° C, add 200 ppm of anhydrous zinc acetate, add butanediol, control the system diol: diacid = 1.2:1, esterify for 1-2 hours, until the distillate reaches more than 95% of the theoretical distillate amount.

[0111] Step 3: After the esterification is completed, 300 ppm of tetrabutyl titanate is added as a catalyst to carry out a condensation reaction. The vacuum degree in the kettle is slowly reduced, and the temperature is further raised to 250°C. The vacuum degree is maintained below 50 Pa and the reaction is terminated after 4-6 hours to obtain a modified PBAT polymer.

[0112] Example 1-2 to Example 1-5

[0113] The modified unit content was changed to 10%, 20%, 30% or 50%, and the modified PBAT polymer was synthesized according to the method of Example 1-1, as shown in Table 1.

[0114] Example 2-1 to Example 2-5

[0115] Aspartic acid was replaced with 2-amino-1,3-propanediol, and modified PBAT polymers with a modified unit content of 5%, 10%, 20%, 30% or 50% were synthesized according to the methods of Examples 1-1 to 1-5, as shown in Table 2.

[0116] Example 3-1 to Example 3-5

[0117] Aspartic acid was replaced with 3-amino-1,2-propanediol, and modified PBAT polymers with a modified unit content of 5%, 10%, 20%, 30% or 50% were synthesized according to the methods of Examples 1-1 to 1-5, as shown in Table 3.

[0118] Comparative Example 1

[0119] 1,4-Benzenedicarboxylic acid, 1,6-hexanodioic acid and butanediol, wherein the molar ratio of each material satisfies 1,4-Benzenedicarboxylic acid: adipic acid = 9:11, (1,4-Benzenedicarboxylic acid + adipic acid): butanediol = 1:1.2, and 200ppm of antioxidant and heat stabilizer are added, and the temperature is raised under nitrogen protection, and the reaction is kept at 160℃ for 2h; then the temperature is continued to be raised to 220℃ and the reflux reaction is continued for 3h to complete the preliminary esterification and dissolution of 1,4-Benzenedicarboxylic acid; then the temperature is raised to At 200°C, 200 ppm of anhydrous zinc acetate was added, and butanediol was added to control the diol:diacid ratio of the system to 1.2:1. The reaction was carried out for 1-2 hours until the theoretical distillate of the fraction reached more than 95%. After the esterification, 300 ppm of tetrabutyl titanate was added as a catalyst to carry out a polycondensation reaction. The vacuum degree in the reactor was slowly reduced, and the temperature was further increased to 250°C. The vacuum degree was maintained below 50 Pa for 4-6 hours before the reaction was terminated to obtain a PBAT polymer.

[0120] The resin materials obtained in the Examples and Comparative Examples were tested for tensile strength and elongation at break in accordance with GB / T 1040.2-2006. The melting temperature (Tm) of the resin materials obtained in the Examples and Comparative Examples was tested in accordance with GB / T 19466.2-2004. The melt flow index (MFI) was tested in accordance with ASTM D1238-2010.

[0121] Table 1

[0122]

[0123] Table 2

[0124]

[0125]

[0126] Table 3

[0127]

[0128] As can be seen from Tables 1 to 3, the aromatic polyester (modified PBAT) containing the modified unit (cyclic imide segment) of the present invention has better tensile strength and / or melting point than the comparative example (pure PBAT polymer), indicating that the cyclic imide segment can improve the mechanical properties and / or thermal properties of the polymer.

[0129] In the above embodiments, all technical solutions that fall within the scope of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, several improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. An aromatic polyester containing a cyclic imide structure, the aromatic polyester containing a cyclic imide structure comprising a benzene ring-containing aromatic polyester main structural unit and a modification unit, wherein the benzene ring-containing aromatic polyester main structural unit comprises a polyester unit obtained by polymerizing a diol used for polymer synthesis with a benzene ring-containing dibasic acid / anhydride / ester; the modification unit comprises a first modification unit and / or a second modification unit, wherein the first modification unit comprises a structure of formula (I): R1 is selected from an alkylene group having 1 to 7 carbon atoms, preferably a straight or branched alkylene group having 1, 2, 3 or 4 carbon atoms in the main chain, an arylene group having 6 to 12 carbon atoms, a heteroarylene group having 5 to 11 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, a heterocycloalkylene group having 2 to 11 carbon atoms or a combination thereof, optionally containing the following substituents: halogen, nitro, C1-C4 alkyl, halogenated C1-C4 alkyl, C6-C 12 Aryl, C6-C 12 Aryl-C1-C4 alkyl or halogenated, C1-C4 alkyl substituted C6-C 12 Aryl or C6-C 12 Aryl-C1-C4 alkyl; R2 is selected from a linear alkylene group having 2 to 12 carbon atoms, a branched alkylene group having 3 to 12 carbon atoms, an arylene group having 6 to 12 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, or a trivalent C1-C5 alkyl-C6-C8 aryl-C1-C5 alkyl group, optionally containing the following substituents: halogen, nitro, C1-C4 alkyl, halogenated C1-C4 alkyl, C6-C8 alkyl, C1-C5 ... 12 Aryl, C6-C 12 Aryl-C1-C4 alkyl or halogenated, C1-C4 alkyl substituted C6-C 12 Aryl or C6-C 12 Aryl-C1-C4 alkyl; The second modifying unit comprises a structure of formula (II): Wherein Asp is the residue of aspartic acid; X is selected from an alkylene group having 1 to 7 carbon atoms, preferably a linear or branched alkylene group having 1, 2, 3 or 4 carbon atoms in the main chain, an arylene group having 6 to 12 carbon atoms, a heteroarylene group having 5 to 11 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, a heterocycloalkylene group having 2 to 11 carbon atoms or a combination thereof, optionally containing the following substituents: halogen, nitro, C1-C4 alkyl, halogenated C1-C4 alkyl, C6-C 12 Aryl, C6-C 12 Aryl-C1-C4 alkyl or halogenated, C1-C4 alkyl substituted C6-C 12 Aryl or C6-C 12 Aryl-C1-C4 alkyl; n is an integer of 0 or greater; preferably, when n is greater than 0, the content of the second modifying unit is greater than 0.

2. The aromatic polyester containing a cyclic imide structure according to claim 1, wherein the structure of the first modifying unit is: wherein R3 is a C2-C4 straight or branched alkylene, 1,4-cyclohexylene or 1,4-phenylene, and * indicates the connection position with other units; Preferably, R2 is a residue of 2-amino-1,3-propanediol or 3-amino-1,2-propanediol; Preferably, R1 is a succinic acid residue (i.e., ethylene); Preferably, R3 is a succinic acid residue.

3. The aromatic polyester containing a cyclic imide structure according to claim 1, wherein the first modifying unit accounts for 1-50 mol%, preferably 5-50 mol%, of the total structural units in the aromatic polyester containing a cyclic imide structure.

4. The aromatic polyester containing a cyclic imide structure according to claim 1, wherein the structure of the second modifying unit is: Wherein Asp is an aspartic acid residue, X is ethylene, 1,2-cyclohexylene or 1,2-phenylene, R4 is a diol residue used for polymer synthesis and comprises a butanediol residue, preferably a 1,4-butanediol residue, or a combination of a 1,4-butanediol residue and a propylene glycol or ethylene glycol residue, * indicates the connection position with other units; n is an integer of 0 or greater; preferably, when n is greater than 0, the content of the second modifying unit is greater than 0; Preferably, X is ethylene; preferably, R4 is ethylene.

5. The aromatic polyester containing a cyclic imide structure according to claim 1, wherein the second modified structural unit accounts for 0.5-99.5 mol%, preferably 1-90 mol%, and more preferably 5%-50 mol% of the total structural units in the aromatic polyester containing a cyclic imide structure.

6. The aromatic polyester containing a cyclic imide structure according to any one of claims 1 to 5, wherein the aromatic polyester containing a cyclic imide structure comprises a first modification unit and a second modification unit separately or simultaneously. Preferably, the aromatic polyester containing a cyclic imide structure further comprises a third modification structure unit.

7. A polymer alloy comprising the aromatic polyester containing a cyclic imide structure according to any one of claims 1 to 6.

8. A polymer composition or a molded article comprising the aromatic polyester containing a cyclic imide structure according to any one of claims 1 to 6.

9. Use of the aromatic polyester containing a cyclic imide structure according to any one of claims 1 to 6, or the polymer alloy according to claim 7, or the polymer composition or molded article according to claim 8, comprising food containers, food packaging films, disposable tableware such as spoons or straws, packaging containers such as transparent boxes for daily necessities, cosmetics, and household appliances, transparent windows for cartons, transparent folders, stationery such as ID holders, industrial films or agricultural films, and chemical fibers for clothing or industry.

10. A method for preparing an aromatic polyester containing a cyclic imide structure according to any one of claims 1 to 6, comprising: 1) Provide: The diol monomer represented by formula V is: Wherein: R1 and R2 are defined as described in any one of claims 1 to 6; or / and Aspartic acid monomer represented by formula VI: Wherein Asp is an aspartic acid residue, X is defined as described in any one of claims 1 to 6, and n is an integer of 0 or greater than 0; preferably, when n is greater than 0, the content of the second modified unit is greater than 0; 2) subjecting the diol monomer or / and aspartic acid monomer, a benzene ring-containing dibasic acid / ester / anhydride, optionally one or more other dibasic acids / esters / anhydrides used for polymer synthesis, and a diol used for polymer synthesis to an esterification / transesterification reaction, or subjecting the diol monomer or / and aspartic acid monomer to an esterification / transesterification reaction with a prepolymer to obtain an aromatic polyester containing a cyclic imide structure and comprising a first modifying unit or / and a second modifying unit, wherein the prepolymer is obtained by subjecting the dibasic acid / ester / anhydride containing a benzene ring, optionally one or more other dibasic acids / esters / anhydrides used for polymer synthesis, and a diol used for polymer synthesis to an esterification / transesterification reaction.

Images