A plasticizer and its preparation and application

Abstract

This invention discloses a plasticizer, its preparation method, and its application, belonging to the field of composite material technology. Targeting the unique ester groups and cyclic ether structures contained in PVB resin, this invention uses bio-derived tartaric acid and alcohols and aldehydes with different carbon numbers as raw materials to prepare a tartaric acid diester acetal plasticizer containing ester groups, ether bonds, and cyclic structures through a simple esterification and acetal reaction. The tartaric acid diester acetal of this invention exhibits excellent compatibility with a wide variety of plasticizers; therefore, the tartaric acid diester acetal plasticizer can be used in combination with various plasticizers to meet specific or complex application requirements. The tartaric acid diester acetal plasticizer of this invention can be used for plasticizing various polymers, including PVB, and is suitable for various polymer products, including PVB film products.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, and relates to a plasticizer and its preparation and application. Background Technology

[0002] PVB (Polyvinyl Butyral Resin, chemical structure as shown in Formula 1) film, also known as PVB film, is a polymer material made from polyvinyl butyral resin through plasticization and extrusion molding with plasticizers. It is widely used in architectural safety glass, automotive safety glass, and solar photovoltaic module encapsulation films. PVB films produced with special formulations also have extensive applications in aerospace, military, and high-tech industries.

[0003]

[0004] Formula 1

[0005] Plasticizers must be added during the production of PVB films, and the selected plasticizers must have good compatibility with PVB resin. Otherwise, the plasticizers are prone to leaching, affecting the adhesion strength between the film and the inorganic glass; they are also prone to bubbling, thus affecting the impact resistance of the safety glass; at the same time, the amount of plasticizer used cannot reduce the mechanical properties of the film too much; additionally, the plasticizer is required to have high transparency so as not to introduce stains into the final film product; it should also have low polarity and not easily absorb water. There are many types of plasticizers that can be used as PVB resin, but because various plasticizers have different polarities, molar masses, and compatibility with PVB resin, the mechanical properties and durability of the resulting films also vary.

[0006] Currently, the plasticizers used in commercially available PVB films are mainly aliphatic diesters of triethylene glycol or tetraethylene glycol. These include 3GH, 3G7, 3G8, and 4G7, where the leading number in the designation indicates the repeating unit H-(O-CH2-CH2) of the oligoethylene glycol. nIn the -OH group, n and H represent ethyl butyrate, 7 represents n-heptanoate, and 8 represents 2-ethylhexanoate. Triethylene glycol diisooctanoate (3G8) is the most widely used plasticizer in PVB films, as seen in patents CN116396580A, CN120737524A, CN208745475U, CN118853026A, CN118849570A, CN120484712A, CN120923818A, CN118812979A, CN120552467A, CN117698261A, CN118562240A, CN116355339A, CN119978603A, CN112625390A, CN117801714A, and CN10. CN119974703B, CN120484720A, CN118884595A, CN116376474A, CN114907659A, CN104844739A, CN118027854A, CN118460123A, and CN115959356B all mention using 3G8 as a plasticizer, which can be used to prepare PVB films with multiple properties such as heat insulation, radiation protection, light transmission, sound insulation, and impact resistance.

[0007] In addition, aliphatic diesters can also be used as plasticizers to prepare PVB films. For example, patent CN121062308A uses dioctyl sebacate to prepare a high heat insulation and sound insulation PVB interlayer film; patent CN102510591A uses dibutyl sebacate to prepare a defogging and defrosting glass film; patent CN114619735A uses aliphatic diesters to prepare a PVB composite film; patents BR112013021470B1 and BR112013021470A2 respectively mention the use of heptyl ester and diheptyl ester as PVB plasticizers; patent CN104877581A uses dibenzyl sebacate to prepare a privacy PVB heat insulation film; and patent CN120590878A uses dioctyl sebacate, dibutyl adipate, diisobutyl adipate, dipropyl adipate, and diisopropyl adipate to prepare PVB films.

[0008] Polyester plasticizers have a large molecular weight and are widely used due to their strong stability and durability. Patent US20170292005A1 discloses a plasticizer composition containing polydicarboxylate as a plasticizer for PVB; patent US20170233548A1 relates to a plasticizer composition containing polycarboxylate for PVB; patent WO2003018686A2 mentions that polyester polymer plasticizers can be used for PVB; and patent EP3189098B1 designs a plasticizer composition containing polymer dicarboxylate.

[0009] In existing technologies, the aforementioned linear plasticizers have a tendency to migrate. This means that during use, they gradually diffuse from the PVB matrix to the surface and even migrate to other materials in contact with it. Therefore, in some PVB film manufacturing processes, benzoic acid ester plasticizers are used to replace traditional easily migrating linear plasticizers, which can significantly improve the application performance and long-term stability of PVB films. For example, patent CN120442176A uses diisononyl phthalate to prepare an anti-aging PVB encapsulation film for photovoltaic modules; patent CN116825887A uses dioctyl phthalate to prepare a PVB film for solar photovoltaic modules; patent CN119979057A uses dibutyl phthalate and dioctyl phthalate to prepare a PVB encapsulation film; patent CN117698261A uses dibutyl phthalate to prepare a transparent PVB film; patent CN104877581A uses dibutyl phthalate to prepare a privacy PVB heat-insulating film; and patent CN119955242A... High infrared transmittance and low visible light transmittance PVB film is prepared using dioctyl phthalate; patent CN120399292A uses diisobutyl phthalate to prepare a heat-insulating and sound-insulating PVB interlayer film; patent CN118082355A uses dibutyl phthalate to prepare a high-strength and tough layered TiCx / Ti-based composite material; patent CN111993722A uses dipropylene glycol dibenzoate to prepare a low-frequency single-cell hollow sound-insulating composite glass; patent CN115612233A uses dibutyl phthalate to prepare a temperature-controlled color-changing PVB interlayer film material; patent CN103171121B uses dibutyl phthalate to prepare a PVB interlayer film material with high infrared transmittance and low visible light transmittance. Dioctyl formate is used to prepare PVB interlayer film for solar photovoltaic power generation; Patent CN114835992B uses diisooctyl phthalate, dibutyl phthalate, diisobutyl phthalate, di(butoxyethyl) phthalate, and di(methoxyethyl) phthalate to prepare a low-temperature resistant and sound-insulating PVB glass interlayer film; Patent CN121022299A uses benzoic acid ester plasticizers to prepare PVB film for PDLC dimming glass; Patent CN120442176A uses diisononyl phthalate to prepare an anti-aging PVB film for photovoltaic module encapsulation; Patent CN116825887A uses diisooctyl phthalate... Dioctyl phthalate is used to prepare solar photovoltaic modules; patents CN107658486B, CN118684986A, CN121022299A, CN116554801A, CN117841507B, CN101925571A, CN100999590B, CN105884619A, EP1808457A1, CN101925571A, CN118684986A, CN107936291A, CN119979057A, etc., use benzoic acid ester plasticizers to prepare a series of PVB compositions, films, etc.

[0010] Besides benzoic acid esters, polyacid ester plasticizers also possess a cyclic central structure, meeting the requirements for migration resistance. Furthermore, the polyacid structure offers cross-linking advantages, resulting in larger molecular weights and stronger stability. Patent CN112979467A discloses the application of a cyclohexanetripropionic acid triester as a PVB plasticizer; patent US11932749B2 relates to the application of a plasticizer composition containing 1,2,4-cyclohexanetricarboxylic acid tripentyl ester as a PVB plasticizer. CN107011535A relates to the use of trimellitic acid tripentyl ester for PVB plasticizing; patent JP2024052632A discloses a method for preparing tetraisopentyl butanetetracarboxylic acid and its use as a plasticizer; patent CN117801366A adds tetraisopentyl butanetetracarboxylic acid to PVB preparation; and patent CN110078971A uses trimellitic acid tripentyl ester for PVB plasticizing.

[0011] In addition, phosphate ester plasticizers are also used in PVB preparation processes, as mentioned in patents CN11824031B, CN114479680A, CN110655336A, and CN119930877A.

[0012] The aforementioned plasticizers primarily meet the plasticizing requirements of PVB resins due to their ester group content and relatively low polarity. In addition to ester groups, PVB structures also contain ether bonds; based on the principle of "like dissolves like," plasticizers containing ether bonds are also compatible with PVB. Furan-based plasticizers are widely used. For example, patent EP2984076A1 mentions tetrahydrofuran derivatives and their use as plasticizers; patent EP2678323B1 uses heptyl furan dicarbonate as a plasticizer; patent EP2678321B1 uses C11-C13 dialkyl esters of furan carboxylic acid as plasticizers; patent US20210371622A1 discloses the preparation and use of plasticizers based on 2,4-furan dicarboxylic acid diester isomers; and patent ES2639043T3 uses pentyl furan dicarboxylic acid as a plasticizer. Besides furans, patents such as CN1746220A and JP2006077251A mention that carboxylic acid ester plasticizers containing ether bonds also have good compatibility with PVB.

[0013] Based on the analysis of the known relationship between the structure and compatibility of plasticizers, the good compatibility of ester-based plasticizers (such as aliphatic diesters, diesters, and polyesters of triethylene glycol or tetraethylene glycol) with PVB is due to the presence of ester groups with similar structures; cyclic plasticizers (such as benzoic acid esters and polyesters) have strong migration resistance because their rigid structures affect the glass transition temperature; ether-based plasticizers (furans and ether-bonded carboxylic esters) contain ether bonds, thus having good compatibility with PVB; and all of the above plasticizers have low polarity, satisfying the principle of similarity and compatibility with PVB in terms of polarity angle.

[0014] Therefore, this invention designs a tartaric acid diester acetal plasticizer containing ester groups, ether bonds, and ring structures, combining the advantages mentioned above. The chemical structure of tartaric acid is shown in Formula 2a. Tartaric acid is mainly extracted from plants such as grapes and tamarind. It is a renewable byproduct of winemaking, produced through fermentation and precipitation. Most tartaric acid derivatives are biodegradable and have been widely used in the food industry, effervescent antacids, and pharmaceutical synthesis.

[0015]

[0016] Equation 2a

[0017] Tartaric acid has been used in the preparation of plasticizers before: Krzysztof Zawada et al. published an article entitled "Esters of Tartaric Acid, A New Class of Potential “Double Green” Plasticizers" in the journal ACSSustainable Chemistry & Engineering in 2017. They modified the carboxyl group by esterification with various long-chain alcohols and etherified the hydroxyl group with dimethyl sulfate and sodium hydride to obtain the plasticizer shown in Formula 2b.

[0018]

[0019] Equation 2b

[0020] R is one of methyl, ethyl, butyl, octyl, or 2-ethylhexyl.

[0021] In their 2018 article "Biobased Plasticizers from Tartaric Acid, an Abundantly Available, Renewable Material" published in the journal Industrial & Engineering Chemistry Research, Bob A. Howell and Wenxiao Sun modified the carboxyl groups by esterification with ethanol or isopropanol and the hydroxyl groups by etherification with benzoyl chloride or benzyl bromide to obtain plasticizers as shown in Formula 2c.

[0022]

[0023] Equation 2c

[0024] Where R is ethyl or hexyl.

[0025] In an article titled "Biobased Plasticizers from Tartaric Acid: Synthesis and Effect of Alkyl Chain Length on the Properties of Poly(vinyl chloride)" published in ACS Omega in 2021, Huichao Zhu et al. modified tartaric acid by esterification with butanol and hydroxyl groups by etherification with alkyl acyl chloride to obtain plasticizers with the structure shown in Formula 2d.

[0026]

[0027] Formula 2d

[0028] Where R is an alkyl group having 1 to 11 carbon atoms.

[0029] In their 2025 article "Synthesis, Characterization, and Performance Evaluation of Bio-Based Plasticizer for Polyvinyl Chloride Derived from Tartaric Acid" published in ChemistrySelect, Fang Shen et al. described how to modify tartaric acid by esterification of the carboxyl group with heptanol and etherification of the hydroxyl group with isobutyric anhydride to obtain a plasticizer with the structure shown in Formula 2e.

[0030]

[0031] Formula 2e

[0032] The aforementioned literature describes the structural modification of tartaric acid plasticizers by altering the four functional groups of tartaric acid through esterification of carboxyl groups with straight-chain alcohols and direct etherification of hydroxyl groups; and the application scope of the plasticizers is limited to polyvinyl chloride (PVC) resin. Summary of the Invention

[0033] In view of the unique ester group and cyclic ether structure contained in PVB resin, the present invention provides a plasticizer based on tartaric acid diester acetal, the chemical structure of which is shown in Formula 3.

[0034]

[0035] Formula 3

[0036] The tartaric acid diester acetal compound of the present invention can be in the form of a pure cis isomer, a pure trans isomer, or a mixture of cis / trans isomers. Pure isomers and mixtures of isomers with any desired composition are generally suitable as plasticizers.

[0037] R1 is selected from the alkyl structural portion of unbranched and branched C6-C8-aliphatic alcohols; R2 is selected from the alkyl structural portion of branched or unbranched C1-C4 aliphatic aldehydes.

[0038] For the purposes of this invention, C6-C8 aliphatic alcohols comprise straight-chain and branched-chain C6-C8-alkanols. These include n-hexanol, 2-hexanol, 3-hexanol, 4-methylpentanol, n-heptanol, 1-methylhexanol, 2-methylhexanol, 1-ethylpentanol, 2-ethylpentanol, 1-propylbutanol, 1-ethyl-2-methylpropanol, n-octanol, isooctanol, 2-ethylhexanol, and other structural isomers of alcohols having the above general formula. Particularly preferred C6-C8 aliphatic alcohols are n-hexanol, n-octanol, and 2-ethylhexanol. C1-C4 aliphatic aldehydes comprise straight-chain or branched-chain C1-C4-alkanols. These include formaldehyde, acetaldehyde, propionaldehyde, isopropionaldehyde, butyraldehyde, and isobutyraldehyde, and other structural isomers of aldehydes having the above general formula. Particularly preferred are formaldehyde, acetaldehyde, and butyraldehyde.

[0039] This invention further provides a method for manufacturing tartaric acid diester acetal.

[0040] a) Optionally, tartaric acid is reacted with C6-C8-aliphatic alcohol in the presence of a catalyst to produce di(C6-C8-alkyl) tartaric acid ester.

[0041] b) React the di(C6-C8-alkyl) tartrate obtained in step a) with a C1-C4 aliphatic aldehyde or its polymer in the presence of a catalyst to produce a compound of ditartrate acetal.

[0042] The C6-C8 aliphatic alcohols in step a) include, but are not limited to, n-hexanol, 2-hexanol, 3-hexanol, 4-methylpentanol, n-heptanol, 1-methylhexanol, 2-methylhexanol, 1-ethylpentanol, 2-ethylpentanol, 1-propylbutanol, 1-ethyl-2-methylpropanol, n-octanol, isooctanol, 2-ethylhexanol, and other structural isomers of alcohols having the above general formula.

[0043] The C1-C4 aliphatic aldehydes in step b) include, but are not limited to, formaldehyde, acetaldehyde, propionaldehyde, isopropionaldehyde, butyraldehyde, and isobutyraldehyde, and other structural isomers of aldehydes having the above general formula; their polymers are commercially available linear polymers of C1-C4 aliphatic aldehydes, including but not limited to paraformaldehyde and paraacetaldehyde.

[0044] Esterification:

[0045] Conventional methods known to those skilled in the art can be used to convert tartaric acid into the corresponding ester compounds. These include the reaction of at least one alcohol component selected from C6-C8 aliphatic alcohols with tartaric acid. Esterification can be autocatalytic or catalytic, for example with Brønsted or Lewis acids. Regardless of the type of catalysis chosen, a temperature-dependent equilibrium is always formed between the feed (acid and alcohol) and the product (ester and water). To shift this equilibrium in favor of esters, entrainers can be used to help remove reaction water from the batch.

[0046] As esterification catalysts, acids such as sulfuric acid, methanesulfonic acid, or p-toluenesulfonic acid, or metals or compounds thereof, can be used. Suitable are, for example, tin, titanium, and zirconium, which are used in the form of finely crushed metals or suitably in the form of their salts, oxides, or soluble organic compounds.

[0047] Metal catalysts are preferred because they produce fewer byproducts, such as olefins, from the alcohols used compared to proton catalysis. Exemplary representatives of metal catalysts include tin powder, tin(II) oxide, tin(II) oxalate, titanates such as tetraisopropyl orthotitanate orthotitanate orthobutyl orthotitanate, and zirconate esters such as tetrabutyl zirconate.

[0048] The catalyst concentration depends on the type of catalyst. In the case of a preferred titanium compound, it is 0.005-2.0% by mass, particularly 0.01-0.5% by mass, and very particularly 0.01-0.1% by mass, based on the reaction mixture.

[0049] The optimal temperature depends on the feed, reaction progress, and catalyst concentration. These can be readily determined experimentally for each individual case. Higher temperatures increase the reaction rate and promote side reactions, such as dehydration of alcohols or the formation of colored byproducts. To facilitate the removal of reaction water, a dehydrating agent can be distilled from the reaction mixture. The desired temperature or temperature range can be adjusted by the pressure within the reactor.

[0050] In a preferred embodiment, the esterification of tartaric acid is carried out in the presence of the aforementioned alcohol component using an organic or inorganic acid, particularly concentrated sulfuric acid. The amount of the alcohol component is advantageously at least twice the stoichiometric amount based on tartaric acid.

[0051] This esterification can be carried out in the absence of any external solvent or in the presence of an organic solvent.

[0052] If esterification is carried out in the presence of a solvent, the organic solvent used is preferably inert under the reaction conditions. These include, for example, aliphatic hydrocarbons, halogenated aliphatic hydrocarbons, aromatic and substituted aromatic hydrocarbons, and ethers. The solvent is preferably selected from pentane, hexane, heptane, crude gasoline, petroleum ether, cyclohexane, dichloromethane, trichloromethane, tetrachloromethane, benzene, toluene, xylene, chlorobenzene, dichlorobenzene, dibutyl ether, THF, dioxane, and mixtures thereof.

[0053] This esterification can be carried out in the absence of an inert gas or in the presence of an inert gas. The term inert gas generally refers to a gas that does not react with the reacting raw materials, reagents, or solvents or with the resulting product under the dominant reaction conditions. This esterification is preferably carried out without the addition of any inert gas.

[0054] Acetal:

[0055] Conventional methods known to those skilled in the art can be used for the reaction of the di(C6-C8-alkyl) tartrate described in step b) to produce the corresponding diester tartrate acetal. These include the reaction of the di(C6-C8)-alkyl tartrate with at least one C1-C4-aliphatic aldehyde in the presence of a suitable acetal catalyst.

[0056] In one embodiment, bis(C6-C8)-alkyl tartrate can also be reacted with a polymer of at least one C1-C4-aliphatic aldehyde in the presence of a suitable acetal catalyst.

[0057] Available acetal catalysts are conventional catalysts commonly used in acetal reactions, many of which are also used in esterification reactions. These include, for example, inorganic acids such as sulfuric acid and phosphoric acid; organic sulfonic acids such as methanesulfonic acid and p-toluenesulfonic acid; and catalysts selected from tin (IV) catalysts, such as dialkyltin dicarboxylic acids, such as dibutyltin diacetate, trialkyltin alkoxides, monoalkyltin compounds, such as monobutyltin dioxide, tin salts, such as tin acetate or tin oxide; catalysts selected from titanium catalysts: monomeric and polymeric titanates and titanium chelates, such as tetraethyl orthotitanate, tetrapropyl orthotitanate, tetrabutyl orthotitanate, triethanolamine titanate; catalysts selected from zirconium catalysts: zirconate esters and zirconium chelates, such as tetrapropyl zirconate, tetrabutyl zirconate, triethanolamine zirconate; and specific metal catalysts such as aluminum (III) acetylacetonate, chromium (III) acetylacetonate, iron (III) acetylacetonate, cobalt (II) acetylacetonate, nickel (II) acetylacetonate, and zinc (II) acetylacetonate.

[0058] The amount of acetal catalyst used is 0 to 10% by weight, preferably 0 to 5% by weight.

[0059] In a preferred embodiment, the acetalization of di(C6-C8)-alkyl tartrate is carried out in the presence of the aforementioned aldehyde component using an organic or inorganic acid, particularly concentrated sulfuric acid. The amount of the aldehyde component is advantageously at least 1.1 times the stoichiometric amount based on the di(C6-C8)-alkyl tartrate.

[0060] In another embodiment, the method for preparing tartrate diester acetal further includes removing excess aldehyde by vacuum evaporation after the complete conversion of di(C6-C8)-alkyl tartrate ester to tartrate diester acetal.

[0061] The reaction temperature is preferably determined based on the boiling point of the reactants, and therefore the reaction temperature ranges from -20°C to 100°C.

[0062] The acetal can typically be produced under ambient pressure or under reduced or increased pressure. Producing the acetal is preferably done under ambient pressure or reduced pressure.

[0063] This acetal can be produced in the absence of any external solvent or in the presence of an organic solvent.

[0064] If the acetal reaction is carried out in the presence of a solvent, the organic solvent used is preferably inert under the reaction conditions. Suitable solvents, in addition to the solvents mentioned above for esterification, also include esters.

[0065] The acetal reaction can be carried out in the absence of an inert gas or in the presence of an inert gas. The term "inert gas" generally refers to a gas that does not react with the reacting raw materials, reagents, or solvents, or with the resulting product, under the dominant reaction conditions. Preferably, the acetal reaction is carried out without the addition of any inert gas.

[0066] In another embodiment, the method for preparing tartrate diester acetal further includes removing impurities, such as titanium catalysts, from the resulting tartrate diester acetal. In one embodiment, the method for preparing tartrate diester acetal further includes dissolving the obtained compound in dichloromethane to form a solution; treating the solution with activated carbon to absorb impurities, such as titanium catalysts, onto the charcoal; filtering the treated solution to remove the charcoal and impurities adsorbed onto the charcoal; and evaporating the dichloromethane under vacuum.

[0067] The tartaric acid diester acetal of the present invention can be in the form of a pure cis-isomer, a pure trans-isomer, or a mixture of cis / trans-isomers. The pure isomer and any mixture of isomers of desired composition are equally suitable as plasticizers.

[0068] Plasticizer Composition

[0069] The tartaric acid diester acetals of this invention exhibit excellent compatibility with a wide variety of plasticizers. They are particularly suitable for combination with other plasticizers that still require improvement in gelling properties to enhance gelling performance: they can lower the temperature required for gelation of thermoplastic polymers and / or can increase the gelation rate of the plasticizer composition.

[0070] If an application requires specific or complex requirements, such as high low-temperature elasticity, high resistance to extraction or migration, or extremely low plasticizer volatility, it is advantageous to use plasticizer compositions to plasticize thermoplastic polymers. This is especially true for PVB film applications.

[0071] Therefore, the present invention also provides a plasticizer composition comprising at least one tartrate diester acetal and at least one plasticizer different from tartrate diester acetal.

[0072] Regarding suitable and preferred tartrate diester acetals for the manufacture of plasticizer compositions, refer to the entirety of the previously described suitable and preferred tartrate diester acetals. The plasticizer compositions of the present invention preferably comprise at least one tartrate diester acetal, wherein R1 is an unbranched or branched C6-C8-alkyl group, particularly hexyl, octyl, or 2-ethylhexyl; and R2 is an unbranched or branched C1-C4-alkyl group, particularly methyl, ethyl, or butyl.

[0073] The preferred plasticizers, unlike tartaric acid diester acetals, are selected from diethylene glycol esters, triethylene glycol esters, and phthalic acid C4-C. 13 Dialkyl esters, alkyl benzoates, trialkyl trimellitate, dialkyl adipate, alkyl 1,2-cyclohexanedicarboxylate, alkyl 1,3-cyclohexanedicarboxylate, alkyl 1,4-cyclohexanedicarboxylate, glycerides, isosorbide esters, epoxidized vegetable oils, saturated and unsaturated fatty acid esters (which may be fully or partially epoxidized), tricitrate, alkylpyrrolidones, and combinations thereof.

[0074] In a preferred embodiment, the mass ratio of the additional plasticizer to dimethyl tartrate acetal used is 1:20 to 20:1, particularly preferably 1:20 to 10:1, and very particularly preferably 1:20 to 5:1.

[0075] Modified polymers

[0076] Another aspect of the present invention provides a modified polymer comprising the aforementioned plasticizer. The tartaric acid diester acetal is present in the modified polymer in an amount of 1-300, more preferably 10-150, or even more preferably 15-80 parts by weight of the compound per 100 parts by weight of the polymer.

[0077] The polymers that can be used are any thermoplastically processable polymers. These thermoplastic polymers are particularly selected from PVB, polyvinyl chloride (PVC), thermoplastic polyurethane (PU), polylactic acid (PLA), polyhydroxybutyral (PHB), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polyether, polysulfide, polysulfone, homopolymers and copolymers of polystyrene (PS), polycarbonate (PC), polyalkyl methacrylate (PAMA), starch, thermoplastic starch (TPS), and combinations thereof.

[0078] The at least one thermoplastic polymer included in the modified polymer of the present invention is preferably polyvinyl butyral (PVB).

[0079] In addition to the components mentioned above, the modified polymers of the present invention may contain one or more suitable additives commonly used in modified polymers, such as light stabilizers, acid stabilizers, heat stabilizers, UV stabilizers, fillers and reinforcing agents, biocides, swelling agents, release additives, lubricants, flow modifiers, impact modifiers, anti-caking agents, antistatic agents, slip agents, pigments and flame retardants.

[0080] The modified polymers of the present invention may contain all fillers corresponding to those in the prior art. Examples of such fillers are mineral and / or synthetic and / or inorganic materials, such as calcium oxide, magnesium oxide, calcium carbonate, barium sulfate, silica, layered silicates, industrial carbon black, pitch, wood (e.g., powdered, as granules, microparticles, fibers, etc.), paper, natural and / or synthetic fibers, etc. At least one filler used is particularly preferred to be quartz powder.

[0081] The plasticizer of the present invention is preferably present as a liquid, particularly as a pumpable liquid.

[0082] The plasticizer of this invention can be used in films, adhesives, sealants, coatings, paints, coatings, plastisols, artificial leather, floor coverings, chassis protection, fabric coatings, cables, wallpaper, or inks. It is particularly preferred for use in glass encapsulation, such as composite glass films.

[0083] Another aspect of the present invention provides a method for preparing a modified polymer comprising a polymer and a tartaric acid diester or plasticizer composition as a plasticizer, wherein the method comprises mixing the polymer, tartaric acid diester and other additives (e.g., antioxidants) in powder or granule / particle form together and filling them into a two-roll mill or homogenizer; and processing the polymer in the mill or homogenizer for more than three minutes to promote the incorporation of the plasticizer and the homogenization of the modified polymer.

[0084] Another aspect of the present invention is a molded article or film product containing the modified polymer of the present invention.

[0085] In one embodiment, the modified polymer product is selected from coatings, inks, adhesives or adhesive components, sealing compounds, coating compositions, varnishes, plastisols, synthetic leather, solvents, lubricants, floor coverings, underlayment protection, fabric coatings, cable or wire insulation, extruded articles, and films. The polymer product is produced by conventional methods such as calendering, extrusion, injection molding, or any other processing technique capable of effectively melting and mixing additives in the composition.

[0086] The modified polymer product of the present invention is particularly preferred to be a PVB film product.

[0087] The modified polymer products of the present invention are particularly preferred to be PVB films for architectural safety glass, PVB films for automotive safety glass, and solar PVB films.

[0088] Another aspect of the present invention is a method for preparing a modified polymer product comprising a composition containing a polymer and a diester tartaric acid acetal as a plasticizer as described above. The method comprises mixing the polymer in powder or granule / particle form, the diester tartaric acid acetal, and other additives such as phenolic antioxidants and benzotriazole UV absorbers together and filling them into a two-roll mill or homogenizer; processing the mixture in the mill or homogenizer for more than three minutes to promote plasticizer incorporation and homogenization of the composition; and processing the resulting homogenized composition into a polymer product by calendering, extrusion, injection molding, or any other processing technique suitable for converting the polymer composition into a polymer product.

[0089] Beneficial effects

[0090] The plasticizer provided by this invention exhibits the following advantages:

[0091] Due to their physical properties, the tartaric acid diester acetals provided by this invention are well-suited for use as plasticizers or components of plasticizer compositions for thermoplastic polymers, particularly PVB.

[0092] The tartaric acid diester acetal provided by this invention has excellent compatibility with PVB.

[0093] The tartaric acid diester acetal of the present invention exhibits excellent migration and penetration resistance in PVB plasticized products.

[0094] PVB products plasticized with the tartaric acid diester acetal of the present invention have excellent anti-aging properties.

[0095] The tartaric acid diester acetal of this invention exhibits excellent compatibility with a wide variety of different plasticizers. These can be combined with conventional plasticizers to improve gelling properties.

[0096] The tartaric acid diester acetal provided by this invention is advantageously suitable for manufacturing plasticized films.

[0097] The tartrate diester acetal provided by this invention is suitable for manufacturing molded articles and films for sensitive applications, such as medical products, food packaging, indoor products such as those for homes and vehicles, and for toys, baby care products, etc.

[0098] The tartrate diester acetal provided by this invention can be manufactured using readily available raw materials. A particular economic and environmental advantage of this invention stems from the possibility of using not only readily available petrochemical raw materials but also renewable raw materials in the manufacture of the tartrate diester acetal provided by this invention. Thus, raw materials, for example, can be obtained from naturally occurring carbohydrates such as grapes or tamarind, while alcohols and aldehydes suitable for functional group modification are available from large-scale industrial processes. Therefore, on the one hand, it meets the requirements of "sustainable" materials, and on the other hand, it achieves cost-effective production.

[0099] The method for producing the tartaric acid diester acetal of the present invention is simple and effective, and therefore these can be readily provided on a large industrial scale. Attached Figure Description

[0100] The embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein...

[0101] Figure 1 Example 2: Dihexyl tartrate butyral 1 H NMR image

[0102] Figure 2 Example 5: Dihexyl tartrate formaldehyde 1 H NMR image

[0103] Figure 3 Example 6: Diisooctyl tartrate acetal 1 H NMR image

[0104] Figure 4 Example 7: Dioctyl tartrate acetal 1 H NMR image Detailed Implementation

[0105] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0106] I. Synthesis Examples

[0107] Example 1: Preparation of dihexyl tartrate by tartrate esterification

[0108] In a 250 mL round-bottom flask, tartaric acid (15.0 g, 0.1 mol, 1 eq.) was dissolved in toluene (100 mL), and n-hexanol (20.6 g, 0.2 mol, 2 eq.) and the catalyst p-toluenesulfonic acid (0.2 g) were added. The apparatus was equipped with a Dean-Stark separator to collect water produced during esterification. The mixture was stirred at 120˚C, and the reaction progress was monitored using thin-layer chromatography until the tartaric acid disappeared, yielding crude dihexyl tartrate.

[0109] Example 2: Preparation of dihexyl tartrate butyral plasticizer from dihexyl tartrate

[0110] Butyraldehyde (28.8 g, 0.4 mol, 4 eq.) was added to the crude dihexyl tartrate, and the mixture was stirred at 60˚C for 24 h. The catalyst was then quenched by adding sodium bicarbonate aqueous solution, the oil phase was separated, and the product was concentrated under vacuum to obtain dihexyl tartrate butyral plasticizer.

[0111] This invention can replicate the same synthetic scheme starting from tartaric acid using other catalysts, the only difference being that the esterification reaction time needs to be extended to a maximum of 24 hours; the same esterification scheme can be replicated using other alcohols, and the synthetic scheme can accommodate alcohols with different chain lengths (C6-C8), such as heptanol, octanol and their mono-, di-, tri-, and tetra-branched structural isomers, as well as mixtures of said alcohols. The same acetal reaction scheme can be replicated using other aldehydes, including formaldehyde, acetaldehyde, paraformaldehyde, and paraacetaldehyde. Other synthetic examples 3-7 of this invention are performed under the conditions in Table 1 to further illustrate the synthetic scheme of this invention.

[0112] Table 1: Experimental Scheme for Plasticizer Synthesis

[0113] Reactant 1 Reactant 2 catalyst reaction temperature Reaction conditions The product obtained Example 3 Tartaric acid (15g, 1 eq.) Isooctyl alcohol (26g, 2 eq.) 1 mL of sulfuric acid 80˚C dehydration Crude diisooctyl tartrate Example 4 Tartaric acid (15g, 1 eq.). Octyl alcohol (52g, 4 eq.) Tetrabutyl titanate 0.5g 80˚C Vacuum concentration after atmospheric reflux Dioctyl tartrate crude product Example 5 Dihexyl tartrate crude product Paraformaldehyde (40g, 1.3eq) No additional catalyst added 60˚C Water separator dehydration Dihexyl tartrate formaldehyde Example 6 Crude diisooctyl tartrate Paracetamol (66g, 1.5eq.) 30 mL of boron trifluoride diethyl ether 60˚C Distillation after atmospheric reflux Diisooctyl tartrate acetal Example 7 Dioctyl tartrate crude product Acetaldehyde (66g, 1.5eq.) 50mL of sulfuric acid 10˚C Distillation after atmospheric reflux Dioctyl tartrate acetal

[0114] Use of the present invention in tartaric acid diester acetal in PVB film-specific materials

[0115] The advantageous properties achievable with the plasticizer of this invention are demonstrated below, for example, in the preparation of films for laminated safety glass. PVB, plasticizer, and additives are mixed in a certain proportion in a high-speed mixer at 20˚C for 3 minutes to obtain a homogeneous mixture. After drying, the mixture is melt-plasticized and extruded using an extruder to obtain a PVB film (film).

[0116] The PVB mass fraction is 100%. Other components used to prepare the film and their mass fractions are shown in Table 2 below.

[0117] Table 2: Formulation Preparations

[0118] plasticizer UV absorber Light stabilizers antioxidants Example 8 Dihexyl tartrate formaldehyde (20) Ultraviolet absorber C81 (0.1%) Light stabilizer 770 (0.1%) Antioxidant 802 (0.3%) Example 9 Diisooctyl tartrate acetal (20) Ultraviolet absorber C81 (0.1%) Light stabilizer 770 (0.1%) Antioxidant 802 (0.3%) Example 10 Dihexyl tartrate butyral (20) Ultraviolet absorber C81 (0.1%) Light stabilizer 770 (0.1%) Antioxidant 802 (0.3%) Comparative Example 1 Triethylene glycol diisooctyl ester (20) Ultraviolet absorber C81 (0.1%) Light stabilizer 770 (0.1%) Antioxidant 802 (0.3%) Comparative Example 2 Dibutyl sebacate (30) Ultraviolet absorber C81 (0.1%) Light stabilizer 770 (0.1%) Antioxidant 802 (0.3%)

[0119] Performance testing

[0120] Thickness was determined according to GB / T 6672-2001, Method for Determination of Thickness of Plastic Films and Sheets; impact value was determined according to JC / T2166-2013; haze and transmittance were determined according to GB / T2410-2008, Method for Determination of Transparent Plastics Transmittance and Haze; tensile strength was measured according to GB / T1040.3-2006; plasticizer migration was determined according to HG / T4454-2012; plasticizer exudation test: PVB film was placed in a sealed container containing saturated copper sulfate aqueous solution and observed at room temperature for 20 days to observe the exudation of plasticizer on the sample surface.

[0121] Table 3: Performance Index

[0122] Testing items standard Example 8 Example 9 Example 10 Comparative Example 1 Comparative Example 2 Haze / % ≤0.6 0.1 0.2 0.15 0.1 0.2 transmittance / % ≥85% 92 90 88 92 87 Thickness / mm - 0.78 0.78 0.78 0.78 0.78 Roughness (front and back sides) / 15-50 30 15 20 25 20 Volatile matter / % 0.35-0.55 0.35 0.39 0.36 0.36 0.48 Dimensional change rate / % ≤12 8 9 9 8 10 Tensile strength / MPa ≥20 40.07 38.40 39.12 42.11 41.06 Fracture tensile strain / % ≥200 392.14 376..25 359.41 385.38 332.11 Knock value 0-9 8 8 8 8 9 Penetration resistance 4m drop impact Not penetrated Not penetrated Not penetrated Not penetrated Not penetrated Plasticizer leaching transparent No significant changes No significant changes No significant changes Slightly cloudy Opaque to the naked eye Plasticizer migration / g - 0.391 0.422 0.436 0.451 0.589

[0123] As can be seen from the various performance indices in the table above, the plasticized film prepared using the plasticizer of this invention has good mechanical properties, low haze, high light transmittance, and high tensile strength. Furthermore, the plasticizer has good compatibility with PVB film and strong resistance to leaching.

[0124] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A plasticizer based on tartaric acid diester acetal, the chemical structure of which is shown in Formula 1. Formula 1 in, R1 is a straight-chain or branched alkyl group with 6-8 carbon atoms; R2 is a straight-chain or branched alkyl group with 0-3 carbon atoms.

2. A method for preparing the tartaric acid diester acetal plasticizer of Formula 1, wherein, R1 and R2 are as defined in claim 1. a) Optionally, tartaric acid is reacted with C6-C8-aliphatic alcohol in the presence of a catalyst to produce di(C6-C8-alkyl) tartaric acid ester. b) React the di(C6-C8-alkyl) tartrate obtained in step a) with a C1-C4 aliphatic aldehyde or its polymer in the presence of a catalyst to produce a compound of ditartrate acetal. The C6-C8 aliphatic alcohols in step a) include, but are not limited to, n-hexanol, 2-hexanol, 3-hexanol, 4-methylpentanol, n-heptanol, 1-methylhexanol, 2-methylhexanol, 1-ethylpentanol, 2-ethylpentanol, 1-propylbutanol, 1-ethyl-2-methylpropanol, n-octanol, isooctanol, 2-ethylhexanol, and other structural isomers of alcohols having the above general formula. The C1-C4 aliphatic aldehydes in step b) include, but are not limited to, formaldehyde, acetaldehyde, propionaldehyde, isopropionaldehyde, butyraldehyde, and isobutyraldehyde, and other structural isomers of aldehydes having the above general formula; their polymers are commercially available linear polymers of C1-C4 aliphatic aldehydes, including but not limited to paraformaldehyde and paraacetaldehyde.

3. A plasticizer composition comprising a plasticizer of Formula 1, comprising at least one compound of Formula 1 as claimed in claim 1 and at least one plasticizer other than the compound of Formula 1.

4. The plasticizer composition according to claim 3, wherein the plasticizer, different from compound 1, is selected from diethylene glycol esters, triethylene glycol esters, and phthalic acid C4-C. 13 Dialkyl esters, alkyl benzoates, trialkyl trimellitate, dialkyl adipate, alkyl 1,2-cyclohexanedicarboxylate, alkyl 1,3-cyclohexanedicarboxylate, alkyl 1,4-cyclohexanedicarboxylate, glycerides, isosorbide esters, epoxidized vegetable oils, saturated and unsaturated fatty acid esters (which may be fully or partially epoxidized), tricitrate, alkylpyrrolidones, and combinations thereof.

5. A modified polymer comprising at least one polymer and a plasticizer as described in claims 1 to 2 or a plasticizer composition as described in claims 3 to 4.

6. The modified polymer according to claim 5, wherein the polymer is selected from the following thermoplastic polymers: PVB (polyvinyl butyral), polyvinyl chloride (PVC), thermoplastic polyurethane (PU), polylactic acid (PLA), polyhydroxybutyral (PHB), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), homopolymers and copolymers of polyether, polysulfide, polysulfone, polystyrene (PS), polycarbonate (PC), polyalkyl methacrylate (PAMA), starch, thermoplastic starch (TPS), and combinations thereof.

7. A method for preparing the modified polymer according to claims 5 to 6, characterized in that, The polymer of claim 6, the plasticizer of claims 1 to 2, or the plasticizer composition of claim 3, and the additives are mixed and filled into a two-roll mill or homogenizer in powder or granule / particle form; and processed with the mill or homogenizer for more than three minutes to promote the incorporation of the plasticizer and the homogenization of the modified polymer.

8. The method for preparing the modified polymer according to claim 7, characterized in that, The additive is one or more suitable additives commonly used in modified polymers, such as light stabilizers, acid stabilizers, heat stabilizers, UV stabilizers, fillers and reinforcing agents, biocides, swelling agents, release additives, lubricants, flow modifiers, impact modifiers, anti-caking agents, antistatic agents, slip agents, pigments and flame retardants.

9. A use of the modified polymer according to claims 5 to 8 as a polymer product, characterized in that, The polymer products include films, adhesives, sealants, coatings, paints, coatings, plastisols, artificial leather, floor coverings, chassis protection, fabric coatings, cables, wallpaper, or inks.

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