Process for preparing polyol carboxylate, polymerizable composition and adhesive

Abstract

The application provides a preparation method of polyol carboxylic acid ester, comprising: performing esterification reaction on polyol and a carboxylic acid composition under the action of a catalyst and a water-carrying agent to obtain polyol carboxylic acid ester; the carboxylic acid composition is selected from 3-mercaptopropionic acid and 3,3'-thiodipropionic acid, and the content of the 3,3'-thiodipropionic acid in the carboxylic acid composition is 0.01-1 wt%. The application also provides a polymer composition and an adhesive. The adhesive provided by the application improves the bonding performance of the adhesive by using the carboxylic acid composition instead of 3-mercaptopropionic acid as the reaction raw material of the polyol carboxylic acid ester.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, and more particularly to methods for preparing polyol carboxylic esters, polymerizable compositions, and adhesives. Background Technology

[0002] Adhesives come in a wide variety of types and are widely used in various fields such as medical and health, aerospace, electronics, printing, and optical instruments. Acrylic adhesives are among the most widely used types of adhesives, and they have many advantages, such as good aging resistance and resistance to yellowing; good transparency, which can be used to bond glass and transparent plastics; and excellent resistance to ultraviolet rays, ozone, and water.

[0003] Pure acrylate systems suffer from oxygen inhibition, affecting adhesive performance, and their low initial viscosity results in a long curing time. Introducing thiols not only effectively solves this oxygen inhibition problem but also imparts photocuring properties to the adhesive, enabling rapid curing at room temperature. This allows for widespread application in heat-sensitive systems, such as in optical lens bonding, nail polish gels, and quantum dot films.

[0004] To address the issues of low crosslinking density and poor adhesion of mono- and di-functional thiols, tri- and tetra-functional macromolecular thiols are currently preferred, and acrylates are prepared by reacting polyol alcohols with mercaptocarboxylic acids such as mercaptopropionic acid.

[0005] Researchers have conducted numerous studies on the curing properties of polythiol-acrylate systems. For example, Chinese patent CN105384906B reports that modifying polythiols with isocyanates can improve the storage stability of adhesives; Chinese patent CN114395361B studies the improvement of adhesive bonding, peeling, and reusability; Chinese patent CN105706264B studies the effect of acrylic resin residues on the generation of large amounts of gas during curing, or the deterioration of adhesion and transparency of the cured product; and Chinese patent CN113943420B reports the use of non-ester thiols to improve the heat and moisture resistance of adhesives. However, there are few reports in the literature on the bonding properties of ester-based polythiol-acrylate adhesives, yet the bonding properties of adhesives are crucial to their application performance. Summary of the Invention

[0006] The technical problem solved by this invention is to provide an adhesive that has excellent bonding properties.

[0007] In view of this, this application provides a method for preparing a polyol carboxylic acid ester, comprising:

[0008] An esterification reaction is carried out on a polyol and a carboxylic acid composition in the presence of a catalyst and a dehydrating agent to obtain a polyol carboxylic acid ester.

[0009] The carboxylic acid composition is selected from 3-mercaptopropionic acid and 3,3'-thiodipropionic acid, and the content of 3,3'-thiodipropionic acid in the carboxylic acid composition is 0.01 to 1 wt%.

[0010] Preferably, the polyol is selected from pentaerythritol or trimethylolpropane.

[0011] Preferably, the catalyst is selected from acidic catalysts, which are selected from one or more of sulfuric acid, hydrochloric acid, phosphoric acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, trichloroacetic acid, tetrabutyl titanate, zinc acetate, phosphotungstic acid supported on a support, zirconic acid supported on a support, and heteropolyacid supported on a support; the dehydrating agent is selected from one or more of petroleum ether, benzene, toluene, xylene, nitrobenzene, chlorobenzene, dichlorobenzene, anisole, diphenyl ether, and cyclohexanedichloroethane.

[0012] Preferably, the catalyst is 0.5 to 5 wt% of the polyol and the carboxylic acid composition, and the dehydrating agent is 0.5 to 3 times the total mass of the polyol and the carboxylic acid composition.

[0013] Preferably, the molar ratio of the polyol to the carboxylic acid composition is determined based on the molar ratio of the hydroxyl group of the polyol to the 3-mercaptopropionic acid of the carboxylic acid composition, and the molar ratio is (0.8 to 1.2):1.

[0014] This application also provides a polymerizable composition comprising a polyol carboxylic ester and an acrylate compound, wherein the polyol carboxylic ester is a polyol carboxylic ester prepared by the preparation method described above.

[0015] Preferably, the acrylate compound is selected from one or more of the following: methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, cyclohexyl acrylate, isooctyl methacrylate, isodecanyl acrylate, tetrahydrofuran acrylate, tetrahydrofurfuryl acrylate, 4-tert-butylcyclohexyl acrylate, isobornyl acrylate, isobornyl methacrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl acrylate, 1,6-hexanediol diacrylate, tricyclodecanediethanol diacrylate, propane triacrylate, trimethylolpropane triacrylate, triallyl isocyanurate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, tricyclodecanediethanol diacrylate, propane triacrylate, trimethylolpropane triacrylate, tripropylene glycol diacrylate, and triallyl isocyanurate.

[0016] This application also provides an adhesive comprising the aforementioned polymeric composition.

[0017] Preferably, the adhesive further includes a photoinitiator selected from tert-butyl 2-ethylhexanoate, tert-butyl benzoate peroxide, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylphenylpropanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphine acid, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinylbenzylphenyl)butanone, 4-benzoyl-4'-methyl-diphenyl sulfide, etc. The following are one or more of the following: 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 1,1'-(methylenedi-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-1-phenylhexanone, bis(2,6-difluoro-3-pyrrolephenyldicyclopentadiene), methyl benzoylformate, benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone, 4-chlorobenzophenone, methyl o-benzoylbenzoate, ethyl 4-dimethylaminobenzoate, isooctyl p-dimethylaminobenzoate, 4,4'-bis(diethylamino)benzophenone, isopropylthioxanthanone, 2,4-diethylthioxanthanone, and 2-ethylanthanone.

[0018] Preferably, the molar ratio of the SH group in the polyol carboxylic acid ester to the C=C group in the acrylate compound is (0.3-2.0):1, and the photoinitiator is 0.2-1 wt% of the total mass of the adhesive.

[0019] This application provides an adhesive comprising a polyol carboxylic ester and an acrylate compound, wherein the polyol carboxylic ester is prepared from a carboxylic acid composition and a polyol, and the carboxylic acid composition is selected from 3-mercaptopropionic acid and 3,3'-thiodipropionic acid; this application uses 3-mercaptopropionic acid and 3,3'-thiodipropionic acid instead of 3-mercaptopropionic acid to prepare the polyol carboxylic ester, and by controlling the content of 3,3'-thiodipropionic acid in the carboxylic acid composition, the adhesiveness of the adhesive can be effectively improved. Attached Figure Description

[0020] Figure 1 The liquid chromatogram of pentaerythritol tetra(3-mercaptopropionic acid) ester prepared in Example 1 of the present invention. Detailed Implementation

[0021] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0022] In view of the insufficient research on the bonding performance of ester-based polythiol-acrylate adhesives in the prior art, this application provides an adhesive that improves the bonding performance of the adhesive, mainly in terms of tensile shear strength and tensile strength, by fundamentally controlling the raw materials of the polyol carboxylate preparation, thereby meeting the application requirements of the adhesive in specific fields and helping to extend the service life of the adhesive. Specifically, this invention first discloses a method for preparing polyol carboxylate, including:

[0023] An esterification reaction is carried out on a polyol and a carboxylic acid composition in the presence of a catalyst and a dehydrating agent to obtain a polyol carboxylic acid ester.

[0024] The carboxylic acid composition is selected from 3-mercaptopropionic acid and 3,3'-thiodipropionic acid, and the content of 3,3'-thiodipropionic acid in the carboxylic acid composition is 0.01 to 1 wt%.

[0025] In the preparation of polyol carboxylic acid esters, a carboxylic acid composition was used to replace 3-mercaptopropionic acid, ultimately improving the adhesive properties of the adhesive. The carboxylic acid composition is selected from 3-mercaptopropionic acid and 3,3'-thiodipropionic acid, and the mass percentage of 3,3'-thiodipropionic acid in the composition is 0.01% to 1%. Specifically, the content of 3,3'-thiodipropionic acid is 0.01 wt%, 0.03 wt%, 0.05 wt%, 0.08 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, or 1.0 wt%. When the mass percentage of 3,3'-thiodipropionic acid is <0.01%, the improvement in adhesive performance is not significant; when the mass percentage of 3,3'-thiodipropionic acid is >1%, the degree of crosslinking after curing of the adhesive is high, and the tensile strength decreases. In this application, there are no particular restrictions on the source of the 3-mercaptopropionic acid and the 3,3'-thiodipropionic acid. They can be commercially available products or prepared separately according to methods known to those skilled in the art.

[0026] The polyol is selected from one or more of trifunctional and tetrafunctional polyols. Specifically, the polyol is selected from pentaerythritol or trimethylolpropane. In a specific embodiment, the polyol is selected from pentaerythritol. The molar ratio of the polyol to the carboxylic acid composition is determined by the molar ratio of the hydroxyl group of the polyol to the 3-mercaptopropionic acid of the carboxylic acid composition as (0.8–1.2):1; specifically, the molar ratio of the polyol to the carboxylic acid composition is determined based on the molar ratio of the carboxyl group of the polyol to the 3-mercaptopropionic acid, and the molar ratio is (0.9–1.1):1.

[0027] The catalyst is selected from acidic catalysts, specifically organic acids, inorganic acids, and solid acids. More specifically, the organic acid is selected from one or more of p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, trichloroacetic acid, dibutyltin dioxide, tetrabutyl titanate, and zinc acetate; the inorganic acid is selected from one or more of sulfuric acid, hydrochloric acid, and phosphoric acid; and the solid acid is selected from phosphotungstic acid, zirconic acid, and heteropoly acids supported on molecular sieves, silica gel, or activated carbon. In a specific embodiment, the catalyst is selected from p-toluenesulfonic acid. The dehydrating agent is selected from one or more of petroleum ether, benzene, toluene, xylene, nitrobenzene, chlorobenzene, dichlorobenzene, anisole, diphenyl ether, and cyclohexanedichloroethane. In a specific embodiment, the dehydrating agent is selected from toluene.

[0028] In the above preparation method, the catalyst is 0.5-5 wt% of the polyol and the carboxylic acid composition, and the dehydrating agent is 0.5-3 times the total mass of the polyol and the carboxylic acid composition; specifically, the catalyst is 0.7-3.5 wt% of the polyol and the carboxylic acid composition, and the dehydrating agent is 0.8-2.6 times the total mass of the polyol and the carboxylic acid composition. In this application, the esterification reaction temperature is determined based on the boiling point of the dehydrating agent, and the reaction temperature is 80-110°C, with a reaction time of 8-10 hours.

[0029] In a second aspect, this application provides a polymerizable composition based on the polyol carboxylate obtained above, comprising the polyol carboxylate prepared by the above method and an acrylate compound.

[0030] In this application, the acrylate compound is selected from one or more of aliphatic acrylates, alicyclic acrylates, and aromatic acrylates. More specifically, the acrylate compound may be selected from monofunctional acrylates, or may be selected from polyfunctional acrylate monomers; the monofunctional acrylate is selected from methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, cyclohexyl acrylate, isooctyl (meth)acrylate, and acrylic acid. The acrylate is selected from one or more of the following: isodecyl acrylate, tetrahydrofuran acrylate, tetrahydrofurfuryl acrylate, 4-tert-butylcyclohexyl acrylate, isobornyl acrylate, isobornyl methacrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl acrylate, 1,6-hexanediol diacrylate, tricyclodecanediethanol diacrylate, propane triacrylate, trimethylolpropane triacrylate, triallyl isocyanurate, and tripropylene glycol diacrylate; in this application, "(methyl)" specifically refers to the optional presence of a methyl group. The polyfunctional acrylate is selected from one or more of 1,6-hexanediol diacrylate, tricyclodecanediethanol diacrylate, propane triacrylate, trimethylolpropane triacrylate, tripropylene glycol diacrylate, and triallyl isocyanurate. In a specific embodiment, the acrylate compound is selected from tricyclodecanediethanol diacrylate and trimethylolpropane triacrylate.

[0031] In a third aspect, this application also provides an adhesive comprising the polymeric composition described above.

[0032] In this application, the adhesive can be thermosetting or UV curing. In a specific embodiment, UV curing is used. In addition, the adhesive further includes a photoinitiator, which is a photoinitiator well known to those skilled in the art. Specifically, the photoinitiator is selected from tert-butyl peroxide, tert-butyl peroxide, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylphenylpropanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphine acid, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinylbenzylphenyl)butanone, 4-benzoyl-4'-methyl-diphenyl sulfide, 2-(4- methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 1,1'-(methylenedi-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-1-phenylhexanone, bis(2,6-difluoro-3-pyrrolephenyldicyclopentadiene), methyl benzoylformate, benzophenone, 4-methylbenzophenone The adhesive comprises one or more of the following: 4-phenylbenzophenone, 4-chlorobenzophenone, methyl o-benzoylbenzoate, ethyl 4-dimethylaminobenzoate, isooctyl p-dimethylaminobenzoate, 4,4'-bis(diethylamino)benzophenone, isopropylthioxanthanone, 2,4-diethylthioxanthanone, and 2-ethylanthraquinone; in a specific embodiment, the photoinitiator is selected from 2,4,6-trimethylbenzoyl-diphenylphosphine oxide. The raw materials of the adhesive also include additives, which are well known to those skilled in the art, and this application does not impose any particular limitations on them.

[0033] Furthermore, there are no particular restrictions on the proportion of polyol carboxylic esters and acrylate compounds used. Generally, the molar ratio of SH groups in the polyol carboxylic ester to C=C groups in the acrylate compound is 0.4 to 1.7, preferably 0.5 to 1.4, and more preferably 0.8 to 1.2. If the molar ratio is within the above range, the UV adhesive made from the adhesive obtained by curing the polymerizable composition will have high bonding strength.

[0034] The photoinitiator comprises 0.2–1 wt% of the total mass of the adhesive raw materials. It ensures efficient pre-curing and facilitates adjustment of the degree of pre-curing. Within this range, as the photoinitiator content increases, the pre-curing speed accelerates, and the degree of pre-curing of the resin system under the same curing conditions shows an upward trend. When the content is less than 0.2 wt%, UV light pre-curing takes a long time, which is detrimental to improving production efficiency. However, when the content is greater than 1 wt%, the number of active sites generated after light irradiation increases significantly, easily leading to uncontrollable pre-curing rate and excessively high curing degree, which is not conducive to the control of subsequent winding and post-curing. Furthermore, excessive photoinitiator content leading to excessive residue in the resin also carries the risk of reducing adhesive performance.

[0035] This application does not impose any particular limitation on the preparation method of the adhesive; any method known to those skilled in the art can be used.

[0036] To further understand the present invention, the preparation method of polyol carboxylic esters provided by the present invention and its application are described in detail below with reference to the embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0037] Example 1

[0038] 1) Synthesis of pentaerythritol tetra(3-mercaptopropionic acid) ester

[0039] 320.7 g (3.0 mol) of a carboxylic acid composition containing 1% 3,3'-thiodipropionic acid and 99% 3-mercaptopropionic acid, 107.3 g (0.75 mol) of pentaerythritol (95.0% purity), 3 g of p-toluenesulfonic acid, and 300 g of toluene were added to a 1 L four-necked flask. The mixture was heated to reflux, and the byproduct water was removed from the system. After reacting for 8 hours, the mixture was cooled to room temperature. The amount of water discharged from the system was 99.1% of the theoretically generated water. The reaction solution was washed with alkali, then with water, and toluene and trace amounts of water were removed under reduced pressure. The mixture was then filtered to obtain the product.

[0040] The product was identified by high-performance liquid chromatography (HPLC). The specific detection method was as follows: a Shimadzu ODS-VP column (5 μm * 150 mm) was connected to an Agilent Technologies 1260 HPLC system. A 0.01 M KH₂PO₄ / acetonitrile (45 / 55) aqueous solution was used as the eluent. The column temperature was 40 °C, the eluent flow rate was 1 mL / min, and the injection volume was 2 μL. Under UV detector conditions and a wavelength of 210 nm, 200 mg of the sample was dissolved and mixed in 10 mL of acetonitrile. The main content of pentaerythritol tetra(3-mercaptopropionic acid) ester in the product was analyzed. The main content of pentaerythritol tetra(3-mercaptopropionic acid) ester was calculated as the area percentage when the total peak area determined by HPLC was taken as 100%. Figure 1 As shown, the peak elution time of pentaerythritol tetra-(3-mercaptopropionic acid) ester was 9.1–10.3 min, and the main content was 73.8%; the calculated yield of pentaerythritol tetra-(3-mercaptopropionic acid) ester was 358.3 g.

[0041] 2) Preparation of adhesives

[0042] The following raw materials were added sequentially to a stirred tank: 36% pentaerythritol tetra(3-mercaptopropionic acid) ester, 45% tricyclodecanediethanol diacrylate, 14.5% trimethylolpropane triacrylate, 0.5% free radical photoinitiator 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide, and the remainder of additives; the mixture was vacuum-sealed to remove air bubbles, packaged, and stored in the dark and at low temperature (0-10℃) to obtain the UV adhesive.

[0043] Example 2

[0044] The pentaerythritol tetra(3-mercaptopropionic acid) ester was synthesized in the same manner as in Example 1, using a carboxylic acid composition containing 0.5% 3,3'-thiodipropionic acid and 99.5% 3-mercaptopropionic acid instead of the carboxylic acid composition in Example 1; the resulting pentaerythritol tetra(3-mercaptopropionic acid) ester had a main content of 73.2%.

[0045] An adhesive was prepared using pentaerythritol tetra(3-mercaptopropionic acid) ester, following the same method as in Example 1.

[0046] Example 3

[0047] The pentaerythritol tetra(3-mercaptopropionic acid) ester was synthesized in the same manner as in Example 1, using a carboxylic acid composition containing 0.01% 3,3'-thiodipropionic acid and 99.99% 3-mercaptopropionic acid instead of the carboxylic acid composition in Example 1; the resulting pentaerythritol tetra(3-mercaptopropionic acid) ester had a main content of 72.5%.

[0048] An adhesive was prepared using pentaerythritol tetra(3-mercaptopropionic acid) ester, following the same method as in Example 1.

[0049] Comparative Example 1

[0050] A carboxylic acid composition containing 0.005% 3,3'-thiodipropionic acid and 99.995% 3-mercaptopropionic acid was used instead of the carboxylic acid composition in Example 1 to synthesize pentaerythritol tetra(3-mercaptopropionic acid) ester in the same manner as in Example 1; the resulting pentaerythritol tetra(3-mercaptopropionic acid) ester had a main content of 72.1%.

[0051] An adhesive was prepared using pentaerythritol tetra(3-mercaptopropionic acid) ester, following the same method as in Example 1.

[0052] Comparative Example 2

[0053] Pentaerythritol tetra(3-mercaptopropionic acid) ester was synthesized in the same manner as in Example 1, using a carboxylic acid composition containing 1.2% 3,3'-thiodipropionic acid and 98.8% 3-mercaptopropionic acid instead of the carboxylic acid composition in Example 1; the resulting pentaerythritol tetra(3-mercaptopropionic acid) ester had a main content of 71.6%.

[0054] An adhesive was prepared using pentaerythritol tetra(3-mercaptopropionic acid) ester, following the same method as in Example 1.

[0055] Comparative Example 3

[0056] Pentaerythritol tetra(3-mercaptopropionic acid) ester was synthesized in the same manner as in Example 1, using 3-mercaptopropionic acid instead of the carboxylic acid composition in the examples; the resulting pentaerythritol tetra(3-mercaptopropionic acid) ester had a main content of 71.3%.

[0057] The adhesive was manufactured using pentaerythritol tetra(3-mercaptopropionic acid) ester in the same manner as in Example 1.

[0058] The adhesives of Examples 1-3 and Comparative Examples 1-3 were subjected to various performance tests according to the following methods:

[0059] Tensile strength test of adhesive: The prepared adhesive is added into a dumbbell mold with a diameter of 150*10*4mm, and cured into a strip by a ZT1365 box-type UV curing machine. The tensile strength of the strip is tested on a universal tensile testing machine. Six strips are used at a time for parallel data and the average value is taken.

[0060] Tensile shear strength test: Apply the prepared adhesive to one end of a 100*20*4mm transparent glass sheet, and overlap it with another glass sheet (overlap area is 20mm*10mm). After overlapping, fix it with a clip and place it in a ZT1365 box-type UV curing machine for pre-curing for 2s. Remove the clip and cure for 1min. Test the tensile shear strength on a universal tensile testing machine. Take 6 parallel data at a time and take the average value.

[0061] The measurement results are shown in Table 1 below;

[0062] Table 1. Performance data of the adhesives prepared in the examples and comparative examples.

[0063]

[0064] Based on the analysis and comparison of the examples and comparative examples in Table 1, it can be seen that when the amount of 3,3'-thiodipropionic acid added is 0.01-1 wt%, the tensile strength and tensile shear strength of the UV adhesive of the present invention are significantly better than those of the comparative example without the addition of thiodipropionic acid. This indicates that the adhesive of the present invention has excellent bonding strength, while there is no obvious effect when the amount added is less than 0.01 wt%, and when it is more than 1%, the tensile strength and shear strength have no significant advantage compared with 1%. Considering cost saving, the appropriate addition range of the carboxylic acid composition is 0.01-1 wt%.

[0065] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0066] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a polyol carboxylic acid ester, comprising: An esterification reaction is carried out on a polyol and a carboxylic acid composition in the presence of a catalyst and a dehydrating agent to obtain a polyol carboxylic acid ester. The carboxylic acid composition is selected from 3-mercaptopropionic acid and 3,3'-thiodipropionic acid, and the content of 3,3'-thiodipropionic acid in the carboxylic acid composition is 0.01~1wt%. The polyol is selected from pentaerythritol.

2. The preparation method according to claim 1, characterized in that, The catalyst is selected from acidic catalysts, which are selected from one or more of sulfuric acid, hydrochloric acid, phosphoric acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, trichloroacetic acid, tetrabutyl titanate, zinc acetate, phosphotungstic acid supported on a support, zirconic acid supported on a support, and heteropolyacids supported on a support; the dehydrating agent is selected from one or more of petroleum ether, benzene, toluene, xylene, nitrobenzene, chlorobenzene, dichlorobenzene, anisole, diphenyl ether, and cyclohexanedichloroethane.

3. The preparation method according to claim 1 or 2, characterized in that, The catalyst is 0.5-5 wt% of the polyol and the carboxylic acid composition, and the dehydrating agent is 0.5-3 times the total mass of the polyol and the carboxylic acid composition.

4. The preparation method according to claim 1, characterized in that, The molar ratio of the polyol to the carboxylic acid composition is determined based on the molar ratio of the hydroxyl group of the polyol to the 3-mercaptopropionic acid of the carboxylic acid composition, and the molar ratio is (0.8~1.2):

1.

5. A polymerizable composition comprising a polyol carboxylic ester and an acrylate compound, wherein the polyol carboxylic ester is a polyol carboxylic ester prepared by the preparation method according to any one of claims 1 to 4.

6. The polymerizable composition according to claim 5, characterized in that, The acrylate compound is selected from one or more of the following: methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, cyclohexyl acrylate, isooctyl methacrylate, isodecanyl acrylate, tetrahydrofuran acrylate, tetrahydrofurfuryl acrylate, 4-tert-butylcyclohexyl acrylate, isobornyl acrylate, isobornyl methacrylate, 2-phenoxyethyl acrylate, 1,6-hexanediol diacrylate, tricyclodecanediethanol diacrylate, propane triacrylate, trimethylolpropane triacrylate, triallyl isocyanurate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, tricyclodecanediethanol diacrylate, propane triacrylate, trimethylolpropane triacrylate, tripropylene glycol diacrylate, and triallyl isocyanurate.

7. An adhesive comprising the polymeric composition according to any one of claims 5 to 6.

8. The adhesive according to claim 7, characterized in that, The adhesive further includes a photoinitiator selected from tert-butyl peroxide, tert-butyl peroxide, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylphenylpropanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphine, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinylbenzylphenyl)butanone, 4-benzoyl-4'-methyl-diphenyl sulfide, 2- One or more of the following: (4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 1,1'-(methylenedi-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-1-phenylhexanone, bis(2,6-difluoro-3-pyrrolephenyldicyclopentadiene), methyl benzoylformate, benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone, 4-chlorobenzophenone, methyl o-benzoylbenzoate, ethyl 4-dimethylaminobenzoate, isooctyl p-dimethylaminobenzoate, 4,4'-bis(diethylamino)benzophenone, isopropylthioxanthraphenone, 2,4-diethylthioxanthraphenone, and 2-ethylanthraquinone.

9. The adhesive according to claim 8, characterized in that, The molar ratio of the SH group in the polyol carboxylic acid ester to the C=C group in the acrylate compound is (0.3~2.0):1, and the photoinitiator is 0.2~1wt% of the total mass of the adhesive.

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