Epoxy-terminated polysulfide polymers, compositions thereof, and methods for producing them

Abstract

The present invention provides a method for easily obtaining, industrially feasible, epoxy-terminated polysulfide polymer compositions that exhibit both high curability and stability. [Solution] The above objective can be achieved by a composition comprising an epoxy-terminated polysulfide polymer obtained from a specific compound and trialkyl borate and / or trialkyl phosphate. Furthermore, the method for producing this composition does not require distillation or washing and can be carried out using simple equipment and processes.

Description

Technical Field

[0001] The present invention relates to an epoxy group-terminated polysulfide polymer, a composition thereof, and a method for producing the same, and particularly relates to a composition having a good balance of high curability and stability.

Background Art

[0002] Due to their excellent physical properties, epoxy resins are used in a wide range of fields including the electrical and electronics industry, civil engineering and construction industry, aerospace industry, and general industry. Particularly in the civil engineering and construction field, attention is paid to the adhesiveness to substrates and chemical resistance that are characteristics of epoxy resins, and epoxy resins are used in applications such as substrate coating agents, heavy anticorrosion paints, linings, fiber sizing agents, and adhesives.

[0003] However, the excellent physical properties of epoxy resins largely depend on the hardness of the cured product, which makes them weak against bending force. There has been a problem that defects such as cracking and chipping often occur in coating on curved surfaces and coating on angled surfaces.

[0004] To solve this problem, technologies such as those described in Patent Documents 1 and 2 have been proposed. Patent Documents 1 and 2 modify highly flexible thiol-terminated polysulfide polymers with a specific type of polyfunctional epoxy resin. However, because an excess of polyfunctional epoxy resin is present to suppress side reactions, the resulting product is a mixture of epoxy-modified polysulfide polymer and polyfunctional epoxy resin, making it unsuitable for applications requiring particularly high flexibility. On the other hand, Patent Documents 3 and 4 propose epoxy-terminated polysulfide polymers obtained by modifying thiol-terminated polysulfide polymers with epichlorohydrin. Unlike Patent Documents 1 and 2, the product obtained by this technology is an epoxy-terminated polysulfide polymer that does not contain epoxy resin, and can therefore be used in applications requiring high flexibility. However, a challenge is that curing is slow at relatively low temperatures, limiting its applicability. Furthermore, purification processes such as washing, filtration, and liquid-liquid separation are required to remove salts generated during manufacturing, resulting in a high burden in terms of the number of processes and waste disposal. In recent years, there has been a demand for more environmentally friendly manufacturing methods, making it difficult to adopt on an industrial scale. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2004 / 099283 [Patent Document 2] Patent No. 7394807 [Patent Document 3] Special Publication No. 2005-526891 [Patent Document 4] Special Publication No. 2006-506470 [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide an epoxy-terminated polysulfide polymer having high curability and flexibility, and in particular to provide an epoxy-terminated polysulfide polymer composition that has a good balance of high curability and stability. [Means for solving the problem]

[0007] In light of the aforementioned problems, the inventors conducted intensive research and found that epoxy-terminated polysulfide polymers having a specific structure exhibit high curability and flexibility, and that their stability can be improved by specific compounds. As a result, they discovered an epoxy-terminated polysulfide polymer composition that achieves both high curability and stability. Furthermore, they found that this epoxy-terminated polysulfide polymer can be obtained by a manufacturing method that does not require washing or purification processes.

[0008] The epoxy-terminated polysulfide polymer of the present invention is characterized by comprising a thiol-terminated polysulfide polymer (a) shown in the following general formula (1), and at least one epoxy compound (b) selected from the group consisting of vinyl glycidyl ether, allyl glycidyl ether, and compounds shown in general formula (2). [ka] (In equation (1), X is a polysulfide linkage group (average number of sulfur atoms: 1.0 to 2.0), and m, n, o, and p are integers greater than or equal to 0.) [ka] (In equation (2), Y is H or CH3, q is an integer between 1 and 10, and r is an integer between 0 and 1.)

[0009] The epoxy-terminated polysulfide polymer composition of the present invention is characterized by comprising the epoxy-terminated polysulfide polymer described above and (c) at least one compound selected from trialkyl borate and trialkyl phosphate. Preferably, this epoxy-terminated polysulfide polymer composition has curability such that a mixture of a modified amine compound and epoxy groups and amino groups are combined in equimolar amounts, with a gel fraction of 50% or more at 40°C for 1.5 days.

[0010] The present invention provides a method for producing epoxy-terminated polysulfide polymers, characterized by reacting a mixed epoxy compound (b) with a ratio of the number of moles of polymerizable double bond groups to the number of moles of thiol groups in the thiol-terminated polysulfide polymer (a) of 1.0 to 2.0 in the presence of a reaction catalyst (d). A quaternary ammonium salt or a quaternary phosphonium salt is preferred as the reaction catalyst (d). This production method does not require washing, filtration, or liquid-liquid purification steps. An epoxy-terminated polysulfide polymer composition can be produced by adding (c) at least one compound selected from trialkyl borate and trialkyl phosphate to the synthesized epoxy-terminated polysulfide polymer. This method is characterized by not requiring a purification step. [Effects of the Invention]

[0011] The epoxy-terminated polysulfide polymer of the present invention can possess both high curability and flexibility. Furthermore, the epoxy-terminated polysulfide polymer composition can achieve a good balance between high curability and stability. That is, it does not contain polyfunctional epoxy resin as a component, and can achieve both excellent low-temperature curability and stability, overcoming the drawbacks of conventional methods. Moreover, the method for producing the epoxy-terminated polysulfide polymer and its composition does not require washing, filtration, or liquid-liquid purification steps in the manufacturing process. [Modes for carrying out the invention]

[0012] The present invention will now be described in detail. The epoxy group-terminated polysulfide polymer of the present invention is a reaction product of a thiol group-terminated polysulfide polymer (a) represented by the following general formula (1) and at least one epoxy compound (b) selected from the group consisting of vinyl glycidyl ether, allyl glycidyl ether and a compound represented by general formula (2).

Chemical Formula

Chemical Formula

[0013] The epoxy group-terminated polysulfide polymer composition comprises the above-mentioned epoxy group-terminated polysulfide polymer and (c) at least one compound selected from trialkyl borate and trialkyl phosphate.

[0014] The thiol group-terminated polysulfide polymer (a) is represented by general formula (1) above, and a liquid polysulfide polymer having fluidity at room temperature is preferably used. In formula (1), X is a polysulfide linking group having an average number of sulfur atoms of 1.0 to 2.0, and refers to the divalent polysulfide group -St- (where S is a sulfur atom, t is an integer of 1 or more, and the average number thereof is 1.0 to 2.0). Further, m, n, o, and p are integers of 0 or more, preferably m is 0 to 29, n is 0 to 2, o is 0 to 29, and p is 0 to 29. As the thiol group-terminated polysulfide polymer (a), a commercially available product such as Thiokol LP (manufactured by Toray Fine Chemicals) can be used. Thiokol LP has several grades depending on molecular weight and degree of branching, any of which may be selected as long as the terminal is a thiol group, but those having a glass transition temperature of the polymer in the range of -50°C to -80°C can be preferably selected. When the glass transition temperature exceeds -50°C, the flexibility that the obtained epoxy group-terminated polysulfide polymer imparts to the cured product thereof decreases, which is not preferable. Here, the glass transition temperature can be measured by thermal analysis such as DSC (differential scanning calorimetry), and can be obtained from manufacturer-provided values measured for the thiol group-terminated polysulfide polymer (a).

[0015] The epoxy compound (b) is at least one selected from the group consisting of vinyl glycidyl ether, allyl glycidyl ether, and compounds represented by general formula (2). Examples of the compound represented by general formula (2) include, but are not limited to, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate glycidyl ether, 2-hydroxymethacrylate glycidyl ether, 4-hydroxybutyl acrylate glycidyl ether, and 4-hydroxybutyl methacrylate glycidyl ether. Compounds having an acrylate group or a vinyl group have high reactivity and are most suitable as a raw material for the compound of the present invention, and glycidyl methacrylate can be preferably used from the viewpoint of being easily commercially available industrially.

[0016] Epoxy-terminated polysulfide polymers are produced by reacting a mixture of epoxy compound (b) and thiol-terminated polysulfide polymer (a) in the presence of a reaction catalyst (d), where the ratio of moles of polymerizable double bond groups in epoxy compound (b) to moles of thiol groups in thiol-terminated polysulfide polymer (a) is preferably 1.0 to 2.0, more preferably 1.0 to 1.5, and even more preferably 1.0 to 1.1. If the molar ratio of polymerizable double bond groups to thiol groups is less than 1.0, thiol groups remain and the desired epoxy-terminated polysulfide polymer cannot be completely obtained. If it exceeds 2.0, a large amount of epoxy compound (b) remains in the product, requiring processes such as washing and purification, which is undesirable.

[0017] The higher the ratio of epoxy compound (b) to thiol-terminated polysulfide polymer (a), the fewer by-products are produced from the addition reaction with the epoxy group, and the more easily the reaction proceeds. When reducing the ratio to avoid the purification step, the reaction should preferably be carried out at a temperature of 0 to 80°C, more preferably 10 to 60°C, and even more preferably 20 to 50°C to suppress the addition reaction with the epoxy group.

[0018] The method for producing epoxy-terminated polysulfide polymers involves a small ratio of epoxy compound (b) to thiol-terminated polysulfide polymer (a), and the reaction is carried out in the presence of a reaction catalyst (d) to allow the reaction to proceed at a relatively low temperature.

[0019] As the reaction catalyst (d), a quaternary ammonium salt or a quaternary phosphonium salt can be preferably selected from the viewpoint of suppressing the addition reaction to the epoxy group. Other tertiary amines can also act as catalysts for the reaction, but they simultaneously induce reactions between epoxy groups and between the epoxy groups and thiol groups of the epoxy-terminated polysulfide polymer, making it difficult to obtain the desired epoxy-terminated polysulfide polymer in high purity.

[0020] Examples of quaternary ammonium salts and quaternary phosphonium salts for reaction catalyst (d) include halogen salts of tetraalkylammonium such as tetramethylammonium chloride and tetrabutylammonium bromide, halogen salts of tetraalkylphosphonium such as tetramethylphosphonium chloride, tetrabutylphosphonium chloride, and tetrabutylphosphonium bromide, and other examples such as triethylbenzylammonium chloride, trimethylbenzylammonium bromide, and dimethylbutylphosphonium bromide. These can be used individually or in combination of two or more. Due to their availability as industrial products, tetrabutylammonium bromide and tetrabutylphosphonium bromide are preferably used.

[0021] The reaction catalyst (d) is preferably used in an amount of 0.1 to 2.0 parts by weight, more preferably 0.1 to 1.0 parts by weight, and even more preferably 0.1 to 0.5 parts by weight, per 100 parts by weight of the thiol-terminated polysulfide polymer. If the amount is less than 0.1 parts by weight, the reaction will not proceed sufficiently, and if it exceeds 2.0 parts by weight, it will cause instability problems such as increased viscosity in the final product.

[0022] The epoxy-terminated polysulfide polymer composition contains an epoxy-terminated polysulfide polymer and at least one compound selected from (c) trialkyl borate and trialkyl phosphate as essential components.

[0023] Examples of trialkyl borates and trialkyl phosphates include trimethyl borate, triethyl borate, tripropyl borate, and tributyl borate. Examples of trialkyl phosphates include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, and tributyl phosphate. The above-mentioned compounds can be used individually or in combination of any two or more.

[0024] (c) At least one compound selected from trialkyl borate and trialkyl phosphate is preferably used in an amount of 0.05 to 2.0 parts by weight, more preferably 0.05 to 1.0 parts by weight, and even more preferably 0.05 to 0.5 parts by weight per 100 parts by weight of the thiol-terminated polysulfide polymer (a). If the amount is less than 0.05 parts by weight, the stability cannot be sufficiently improved, and if it exceeds 2.0 parts by weight, it is undesirable because it reduces the curability when curing the epoxy-terminated polysulfide polymer composition.

[0025] Epoxy-terminated polysulfide polymer compositions can be used alone or in mixtures with commercially available epoxy resins such as common bisphenol-type epoxy resins and aliphatic epoxy resins. These epoxy resin compositions or mixtures can be cured with a curing agent or curing catalyst to become usable in various applications, such as adhesives.

[0026] When curing epoxy-terminated polysulfide polymer compositions, compounds having primary to tertiary amino groups are generally used as curing agents, and commercially available polyamines can be used. For example, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, isophoronediamine, cyclohexylamine, 1,2-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, bis(4-amino-3-methylcyclohexyl)methane, m-xylenediamine, N-aminoethylpiperazine, diaminodiphenylsulfone, m-phenylmethane, diaminodiphenylsulfone, m-phenylenediamine, 4,4'-methylenedianiline, N-benzylethylenediamine, N-cyanoethylxylylenediamine, 1-(2-aminoethyl)piperazine, N,N-diethylamino-n-propylamine, N,N,N',N'-tetramethylhexamethylenediamine, piperidine, menthanediamine, benzyldimethylamine, dimethylaminomethylphenol, 2,4,6-tris(dimethylaminomethyl)phenol, DBU, polyamine epoxy resin adducts produced by reacting epoxy resin with an excess of amine, polyamine-ethylene oxide adducts, polyamine-ethylene oxide adducts, polyamine-propylene oxide adducts, cyanoethylated polyamines, diamines with a silicon main chain, ketimines, or dehydration condensates obtained by reacting polyamines with phenols and aldehydes, etc., imidazoles such as 2-ethyl-4-methylimidazole, modified polyamines (for example, "Adeka Hardener EH-220" manufactured by Asahi Denka Kogyo Co., Ltd., "Adeka Hardener EH-531" manufactured by Asahi Denka Kogyo Co., Ltd., "Ankamin MCA" manufactured by ICI Japan Limited, "Epomete B-002W" manufactured by Yuka Shell Epoxy Co., Ltd., "Epomete N-001" manufactured by Yuka Shell Epoxy Co., Ltd.) ) "Epomate RX-3", Sumitomo Chemical Co., Ltd. "SumiCure-AF", Daito Sangyo Co., Ltd. "Daitokural HD-801CB", Daito Sangyo Co., Ltd. "U-4075", Daito Sangyo Co., Ltd. "Daitokural X-1436", Daito Sangyo Co., Ltd. "Daitokural X-7906", Fuji Kasei Kogyo Co., Ltd. "FujiCure #5420", Fuji Kasei Kogyo Co., Ltd. "FujiCure #5001", Sanyo Chemical Industries, Ltd. "React CA-101", Examples include Sanyo Chemical Industries, Ltd.'s "React CA-681," polyaminoamides (for example, Asahi Denka Kogyo Co., Ltd.'s "Adeka Hardener EH-203," ICI Japan Limited's "Alcamide 501," and Fuji Chemical Industries Co., Ltd.'s "Tomai #245"), and the amount used varies depending on the type of hardener, but generally, about 0.5 to 150 parts by weight are used per 100 parts by weight of the epoxy-modified polysulfide composition.

[0027] The epoxy group-terminated polysulfide polymer composition of the present invention is configured as a curable composition with the curing agent described above, but may be further used by appropriately blending other epoxy resins, reactive diluents, additives, pigments, fillers, etc., as needed, depending on the purpose and application.

[0028] A curable composition comprising an epoxy-terminated polysulfide polymer composition and a curing agent exhibits high curability at relatively low temperatures. A curable composition obtained by blending an epoxy-terminated polysulfide polymer composition and a modified polyamine compound such that the epoxy groups of the epoxy-terminated polysulfide polymer composition and the amino groups of the modified polyamine compound are equimolar should have a gel fraction of preferably 50% or more, more preferably 54% or more, and even more preferably 58% or more at 40°C for 1.5 days. An example of a modified polyamine compound is "Daito Kral X-7906" manufactured by Daito Sangyo Co., Ltd. (amine value of 463 mg KOH / g). [Examples]

[0029] The present invention will be described in detail below with reference to examples, but these examples are not intended to limit the present invention. The raw materials used in the examples are as follows: Thiol-terminated polysulfide polymer (a) - Thiokol LP-3 (thiol group content: 7.05% by weight, manufactured by Toray Fine Chemicals Co., Ltd.) Epoxy compound (b) - GMA: Glycidyl methacrylate (manufactured by NOF Corporation) - 4HBAGE: 4-Hydroxybutyl acrylate glycidyl ether (manufactured by Mitsubishi Chemical Corporation) Epoxy compounds other than epoxy compound (b) - ECH: Epichlorohydrin (Reagent manufactured by Tokyo Chemical Industry Co., Ltd.) A compound selected from trialkyl borate and trialkyl phosphate (c) - Trimethyl borate (Tokyo Chemical Industries, Ltd. reagent) - Tributyl borate (Tokyo Chemical Industries, Ltd. reagent) - Trimethyl phosphate (Tokyo Chemical Industries, Ltd. reagent) Reaction catalyst (d) - Tetrabutylphosphonium bromide (Reagent manufactured by Tokyo Chemical Industry Co., Ltd.) - Tetrabutylammonium bromide (Reagent manufactured by Tokyo Chemical Industry Co., Ltd.) - NaOH: Sodium hydroxide (48% aqueous solution) (Reagent manufactured by Junsei Chemical Co., Ltd.)

[0030] The evaluation method used in the examples is as follows: (1)SH content 0.2-0.5 g (a) of the sample was weighed into a 200 mL beaker and dissolved in 100 mL of pyridine. After adding 10 mL of 2 wt% potassium iodide aqueous solution, the mixture was titrated with iodine standard solution. Using the obtained titration volume (b), the SH content (wt%) was determined based on the prescribed calculation formula. SH content (wt%)=((b-Blank)×f×k) / a×100 a: Sample quantity (g) b: Titration amount (mL) Blank: 0.05 (mL) (Titration volume when no sample is present) k: Measurement coefficient = 0.1654 f: Factor of iodine standard solution

[0031] (2) Epoxy equivalent 0.15-0.25 g (a) of the sample was accurately weighed into a 100 ml Erlenmeyer flask, and 40 ml of tetraethylammonium bromide acetate solution was added to the flask to dissolve the sample. After confirming that the sample was completely dissolved, 1-2 drops of crystal violet indicator (non-aqueous titration reagent) were added, and the sample was titrated with 0.1 N perchlorated acetate solution (non-aqueous titration reagent) (b), with the endpoint being reached when the solution turned yellowish-green. The epoxy equivalent was calculated using the following formula. Epoxy equivalent (g / eq) = (1000 × a) / (0.1 × f × b) a: Sample quantity (g) b: Titration amount (mL) f: Factor of 0.1N-perchloric acid

[0032] (3) Gel fraction (%) A film sample (weight a(g)) stored in a 40°C constant temperature bath was removed after approximately 36 hours and placed in a cylindrical mold container made by stapling stainless steel mesh (100 mesh) into a cylindrical shape. The container was immersed in a toluene bath and stirred at 23°C for approximately 24 hours. After stirring, the cylindrical mold container was removed and dried at 120°C for 2 hours. The weight of the residual film sample after heating (weight b(g)) was measured. The gel fraction (%) was calculated using the formula: weight b / weight a × 100.

[0033] (4) Viscosity increase rate (%) The viscosity of the sample was measured using an E-type viscometer (TV-25, manufactured by Toki Sangyo Co., Ltd.) under the following conditions. Rotor: 1°34′×R24 Rotor code: 01 Measurement range: U Sample volume: 1.1 ml Measurement temperature: 25℃ The viscosity of samples was measured before and after storage tests conducted under conditions of 3 and 6 days in a 70°C atmosphere, and the viscosity increase rate was calculated using the following formula. Viscosity increase rate (%) = (Viscosity after test - Viscosity before test) / Viscosity before test Note that a 3-day storage test under a 70°C atmosphere is equivalent to storage at 20°C for 3 months, and a 6-day storage test under a 70°C atmosphere is equivalent to storage at 20°C for 6 months.

[0034] [Example 1] In a 300 mL four-necked flask equipped with a condenser, thermometer, stirring blade, and nitrogen line, 100.0 parts by weight of Thiokol LP-3 as a thiol-terminated polysulfide polymer (a) (SH group count: 0.214 mol) and 31.9 parts by weight of glycidyl methacrylate (GMA) as an epoxy compound (double bond group count: 0.224 mol) were added, and stirring was started at 20°C. Next, 0.07 parts by weight of tetrabutylphosphonium bromide was added all at once as the reaction catalyst (d), and stirring was continued at 20-30°C for 8 hours. The amount of SH in the reaction solution was analyzed by redox titration, and the reaction was considered complete when the amount of SH disappeared. After the reaction was complete, 0.26 parts by weight of tributyl borate was added as component (c), and the mixture was stirred for 30 minutes to obtain an epoxy-terminated polysulfide polymer composition. The epoxy equivalent of the obtained epoxy-terminated polysulfide polymer was 660 g / eq. Furthermore, the viscosity increase rate of this polymer after storage in a 70°C atmosphere for 6 days was 22%.

[0035] [Example 2] An epoxy-terminated polysulfide polymer was obtained by the same procedure as in Example 1, except that the reaction catalyst (d) in Example 1 was replaced with 0.07 parts by weight of tetrabutylammonium bromide. The epoxy equivalent of the obtained epoxy-terminated polysulfide polymer was 700 g / eq. Furthermore, the viscosity increase rate of this polymer after storage in a 70°C atmosphere for 6 days was 23%.

[0036] [Example 3] An epoxy-terminated polysulfide polymer was obtained by the same procedure as in Example 2, except that component (c) of Example 2 was changed to 0.26 parts by weight of trimethyl borate. The epoxy equivalent of the obtained epoxy-terminated polysulfide polymer was 700 g / eq. Furthermore, the viscosity increase rate of this polymer after storage in a 70°C atmosphere for 6 days was 24%.

[0037] [Example 4] An epoxy-terminated polysulfide polymer was obtained by the same procedure as in Example 2, except that component (c) of Example 2 was replaced with 0.26 parts by weight of trimethyl phosphate. The epoxy equivalent of the obtained epoxy-terminated polysulfide polymer was 700 g / eq. Furthermore, the viscosity increase of this polymer after storage in a 70°C atmosphere for 6 days was 30%.

[0038] [Example 5] An epoxy-terminated polysulfide polymer was obtained by the same procedure as in Example 2, except that the epoxy compound in Example 2 was changed to 45.0 parts by weight of 4-hydroxybutyl acrylate glycidyl ether (4HBAGE) (number of double bond groups: 0.224 mol). The epoxy equivalent of the obtained epoxy-terminated polysulfide polymer was 710 g / eq. Furthermore, the viscosity increase of this polymer after storage in a 70°C atmosphere for 6 days was 6%.

[0039] [Comparative Example 1] An attempt was made to synthesize an epoxy-terminated polysulfide polymer using the same procedure as in Example 1, except that the reaction catalyst (d) from Example 1 was not included. Although stirring was continued for 9 hours at 20-30°C, the amount of SH decreased by only about 8%, and an epoxy-terminated polysulfide polymer was not obtained.

[0040] [Comparative Example 2] An epoxy-terminated polysulfide polymer was obtained by the same procedure as in Example 2, except that it did not contain component (c) of Example 2. The epoxy equivalent of the obtained epoxy-terminated polysulfide polymer was 700 g / eq. Furthermore, the viscosity increase rate of this polymer after storage in a 70°C atmosphere for 6 days was 96%.

[0041] [Comparative Example 3] In a 300 mL four-necked flask equipped with a condenser, thermometer, stirring blade, and nitrogen line, 100.0 parts by weight of Thiokol LP-3 (SH group count: 0.214 mol) as the thiol-terminated polysulfide polymer (a) and 64.74 parts by weight of epichlorohydrin (0.700 mol) as the epoxy compound other than epoxy compound (b) were added, and stirring was started at 20°C. Next, 20.50 parts by weight (0.246 moles) of a 48% sodium hydroxide aqueous solution was added dropwise over 2 hours as reaction catalyst (d), and stirring was continued for 3 hours at a temperature of 30°C or lower. The amount of SH in the reaction solution was analyzed by redox titration, and the reaction was considered complete when the amount of SH disappeared. After the reaction was complete, an equal amount of water was added to the reaction mixture, and stirring was continued at room temperature for 10 minutes. The mixture then separated into an organic layer and an aqueous layer, and the aqueous layer was removed by the separation process. This procedure was repeated three more times. Next, an equal amount of methanol was added to the organic layer, and stirring was continued at room temperature for 10 minutes. Then, the mixture was separated into the organic layer and the methanol layer, and the methanol layer was removed by the separation process. This operation was repeated two more times. The organic layer was removed by distillation at 80°C under reduced pressure to obtain an epoxy-terminated polysulfide polymer. The epoxy equivalent of the obtained epoxy-terminated polysulfide polymer was 910 g / eq. Furthermore, the viscosity increase rate of this polymer after storage in a 70°C atmosphere for 6 days was 3%.

[0042] The synthesis results for the above examples and comparative examples are shown in Table 1, and the stability test results for Examples 1-5 and Comparative Examples 2-3 are shown in Table 2.

[0043] [Table 1]

[0044] [Table 2]

[0045] Curable compositions were obtained by adding an amine (Daitoclar X-7906, manufactured by Daito Sangyo, amine value: 463 mg KOH / g) as a curing agent to the epoxy groups of the epoxy-terminated polysulfide polymer compositions obtained in Examples 1-5 and Comparative Examples 2-3, in an equimolar manner.

[0046] The curable composition prepared as described above was poured onto a PET separator film (30mN / 50mm) (manufactured by ID Create Co., Ltd.), and the same separator film was placed on top of it. A film sample was then prepared using a bar coater set to a film thickness of 100μm.

[0047] The film samples were stored in a 40°C constant temperature bath, and the gel fraction was measured after 1.5 days. Table 3 shows the amounts of curable compositions used in Examples 1-5 and Comparative Examples 2-3, as well as the gel fraction of their cured products.

[0048] [Table 3]

[0049] The results shown in Table 3 indicate that the cured products using the epoxy-terminated polysulfide polymer compositions of Examples 1-5 and Comparative Example 2 exhibit improved curability compared to those produced by the conventional technique shown in Comparative Example 3.

[0050] Furthermore, considering the results of the stability tests in Table 2, it can be seen that the epoxy-terminated polysulfide polymer compositions of Examples 1 to 5 possess a good balance of curability and stability compared to Comparative Examples 2 and 3.

[0051] As described in detail above, the epoxy group-terminated polysulfide polymer composition of the present invention provides a material that has higher curability than the prior art and also exhibits excellent stability.

Claims

1. An epoxy-terminated polysulfide polymer comprising a thiol-terminated polysulfide polymer (a) shown in the following general formula (1), and at least one epoxy compound (b) selected from the group consisting of vinyl glycidyl ether, allyl glycidyl ether, and the compounds shown in general formula (2). 【Chemistry 1】 (In formula (1), X is a polysulfide linking group (average number of sulfur atoms is 1.0 to 2.0), and m, n, o, and p are integers greater than or equal to 0.) 【Chemistry 2】 (In equation (2), Y is H or CH) ３ (where q is an integer between 1 and 10, and r is an integer between 0 and 1)

2. An epoxy-terminated polysulfide polymer composition comprising (c) the epoxy-terminated polysulfide polymer described in claim 1 and at least one compound selected from trialkyl borate and trialkyl phosphate.

3. The epoxy-terminated polysulfide polymer composition according to claim 2, wherein a mixture obtained by blending the epoxy-terminated polysulfide polymer composition and a modified polyamine compound such that the epoxy groups of the epoxy-terminated polysulfide polymer composition and the amino groups of the modified polyamine compound are equimolar, has curability with a gel fraction of 50% or more at 40°C for 1.5 days.

4. A method for producing an epoxy group-terminated polysulfide polymer according to claim 1, characterized in that the mixture is reacted in the presence of a reaction catalyst (d) in a mixed state in which the ratio of the number of moles of polymerizable double bond groups of the epoxy compound (b) to the number of moles of thiol groups of the thiol group-terminated polysulfide polymer (a) is 1.0 to 2.

0.

5. The method for producing an epoxy-terminated polysulfide polymer according to claim 4, wherein the reaction catalyst (d) is a quaternary ammonium salt or a quaternary phosphonium salt.

6. A method for producing an epoxy group-terminated polysulfide polymer according to claim 4 or 5, wherein the manufacturing process does not include washing with water, filtration, or liquid-liquid purification steps.

7. A method for producing an epoxy-terminated polysulfide polymer composition according to claim 4 or 5, characterized in that, after synthesizing an epoxy-terminated polysulfide polymer, (c) at least one compound selected from trialkyl borate and trialkyl phosphate is added.

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