Phenoxy resin, composition, cured article, and method for producing phenoxy resin

Abstract

Provided is a phenoxy resin which has a high biomass component ratio and from which a cured article having high pencil hardness can be produced. The phenoxy resin contains a structure represented by formula (1), a structure represented by formula (2), and a structure derived from a terpene phenolic resin. (In formula (1), R represents a hydrocarbon group having 10 to 18 carbon atoms, and I represents an integer of 1 to 10.) (In formula (2), X represents a hydrocarbon-derived divalent linking group having 1 to 10 carbon atoms, R represents a hydrocarbon group having 10 to 18 carbon atoms, and m represents an integer of 1 to 10.)

Description

Phenoxy resin, composition, cured product, and method for producing phenoxy resin

[0001] The present invention relates to a phenoxy resin, a composition, a cured product, and a method for producing the phenoxy resin.

[0002] Phenoxy resins are useful compounds that have excellent properties such as flexibility, heat resistance, insulation, and adhesion, and are widely used as paints, adhesives, insulating materials, etc. Therefore, various research efforts are being conducted with the aim of creating new phenoxy resins with excellent properties.

[0003] For example, Patent Document 1 discloses a phenoxy resin obtained by reacting a specific bifunctional epoxy compound with a specific bifunctional phenol compound.

[0004] Japanese Patent Application Laid-Open No. 2021-98836

[0005] In recent years, materials with a high biomass content have been attracting attention in the field of paints and the like, as they are expected to contribute favorably to the creation of a recycling-oriented society.

[0006] Conventional phenoxy resins have not been adequately studied regarding the biomass component ratio, leaving room for improvement.

[0007] As a result of extensive research, the present inventors have found that the biomass component ratio can be increased by introducing a structure derived from a plant resource (for example, a structure derived from cardanol) into a phenoxy resin.

[0008] However, although the phenoxy resins incorporating the structure derived from the plant resources have flexibility, they have the problem of low hardness (pencil hardness).

[0009] Therefore, an object of the present invention is to provide a phenoxy resin that has a high biomass component ratio and can give a cured product with high pencil hardness.

[0010] That is, the present invention is a phenoxy resin containing a structure represented by the following formula (1), a structure represented by the following formula (2), and a structure derived from a terpene phenol resin.

[0011] (In formula (1), R is a hydrocarbon group having 10 to 18 carbon atoms, and l is an integer of 1 to 10.)

[0012] (In formula (2), X is a divalent linking group derived from a hydrocarbon and having 1 to 10 carbon atoms, R is a hydrocarbon group having 10 to 18 carbon atoms, and m is an integer of 1 to 10.)

[0013] In the phenoxy resin of the present invention, in the above formulas (1) and (2), R is preferably a hydrocarbon group having 12 to 16 carbon atoms. In the phenoxy resin of the present invention, the above formula (1) is preferably derived from cardanol. In the phenoxy resin of the present invention, the structure derived from the terpene phenol resin is preferably derived from a terpene phenol resin having a softening point of 90°C or higher and 150°C or lower. The composition of the present invention contains the phenoxy resin of the present invention. The composition of the present invention preferably further contains a curing agent. The composition of the present invention preferably further contains a curing catalyst. The cured product of the present invention is obtained by curing the phenoxy resin and / or the composition. The method for producing the phenoxy resin of the present invention includes a step of reacting a compound represented by the following formula (3), a compound represented by the following formula (4), and a terpene phenol resin.

[0014] (In formula (3), R is a hydrocarbon group having 10 to 18 carbon atoms, and n is an integer of 2 to 20.)

[0015] (In formula (4), X is a divalent linking group derived from a hydrocarbon and having 1 to 10 carbon atoms.)

[0016] The present invention can provide a phenoxy resin that has a high biomass component ratio and can give a cured product with high pencil hardness.

[0017] (Phenoxy Resin) The phenoxy resin of the present invention contains a structure represented by the following formula (1), a structure represented by the following formula (2), and a structure derived from a terpene phenol resin.

[0018] (In formula (1), R is a hydrocarbon group having 10 to 18 carbon atoms, and l is an integer of 1 to 10.)

[0019] (In formula (2), X is a divalent linking group derived from a hydrocarbon and having 1 to 10 carbon atoms, R is a hydrocarbon group having 10 to 18 carbon atoms, and m is an integer of 1 to 10.)

[0020] In the above formula (1), R is a hydrocarbon group having 10 to 18 carbon atoms. The hydrocarbon group having 10 to 18 carbon atoms may be linear or branched. Furthermore, the hydrocarbon group having 10 to 18 carbon atoms may be saturated or unsaturated. Of these, the hydrocarbon group having 11 to 17 carbon atoms is preferred, and from the viewpoint of the balance between the biomass component ratio and pencil hardness of the cured product of the present invention, a hydrocarbon group having 12 to 16 carbon atoms is more preferred.

[0021] From the viewpoint of easy availability of raw materials, the above formula (1) is preferably derived from cardanol. Examples of the structure derived from cardanol include those having a cardanol structure in which R is a hydrocarbon group having 15 carbon atoms and 25 to 31 hydrogen atoms.

[0022] In the above formula (1), l means the number of constitutional units represented in parentheses in the above formula (1) in the phenoxy resin. In the above formula (1), l is 1 to 10. The constitutional units represented in parentheses in the above formula (1) may be present consecutively (in blocks) or randomly in the phenoxy resin.

[0023] In the above formula (2), R is a hydrocarbon group having 10 to 18 carbon atoms. The hydrocarbon group having 10 to 18 carbon atoms may be linear or branched. Furthermore, the hydrocarbon group having 10 to 18 carbon atoms may be saturated or unsaturated. Of these, the hydrocarbon group having 11 to 17 carbon atoms is preferred, and from the viewpoint of the balance between the biomass component ratio and pencil hardness of the cured product of the present invention, a hydrocarbon group having 12 to 16 carbon atoms is more preferred.

[0024] In the above formula (2), from the viewpoint of easy availability of raw materials, R may have a cardanol structure, which is a hydrocarbon group having 15 carbon atoms and 25 to 31 hydrogen atoms.

[0025] In the above formula (2), X is a divalent linking group derived from a hydrocarbon and having 1 to 10 carbon atoms. The divalent linking group having 1 to 10 carbon atoms may be linear or branched, or may have a cyclic structure. Specific examples include alkylene groups, alkenylene groups, alkynylene groups, and cycloalkylidene groups. Among these, from the viewpoint of availability, alkylene groups having 3 to 7 carbon atoms are preferred. The divalent linking group having 1 to 10 carbon atoms may contain a non-carbon molecule such as an oxygen atom or a nitrogen atom in the linking group. The divalent linking group having 1 to 10 carbon atoms may have a substituent, and examples of the substituent include an alkyl group, an alkoxy group, a hydroxyl group, an alkoxy-substituted alkyl group, and a carboxyl group.

[0026] In the above formula (2), O １ may be in the ortho, meta or para position relative to X, O ２ may be in the ortho, meta or para position relative to X, but from the viewpoint of availability, they are preferably in the para position relative to X.

[0027] In the above formula (2), m means the number of constitutional units represented in parentheses in the above formula (2) in the phenoxy resin. In the above formula (2), m is 1 to 10. The constitutional units represented in parentheses in the above formula (2) may be present consecutively (in blocks) or randomly in the phenoxy resin.

[0028] The structure derived from the terpene phenol resin has a terpene structure and a phenol structure, which can improve the biomass component ratio and pencil hardness.

[0029] The terpene structure is a structure derived from a terpene monomer. The terpene monomer is classified into, for example, hemiterpenes, monoterpenes, sesquiterpenes, diterpenes, sesterterpenes, triterpenes, sesquaterpenes, and tetraterpenes depending on the number of isoprene units. Among them, a structure derived from a monoterpene is preferred.

[0030] Examples of the monoterpenes include pinene (α-pinene, β-pinene), terpineol (α-terpineol, β-terpineol, γ-terpineol), myrcene, camphene, limonene (d-limonene, l-limonene, dipentene), ocimene (α-ocimene, β-ocimene), alloocimene, phellandrene (α-phellandrene, β-phellandrene), terpinene (α-terpinene, γ-terpinene), terpinolene (α-terpinolene, β-terpinolene, γ-terpinolene, δ-terpinolene), 1,8-cineole, 1,4-cineole, sabinene, paramentadiene, and carene (δ-3-carene).

[0031] The structure derived from the terpene phenol resin is preferably derived from a terpene phenol resin having a softening point of 90°C or higher and 150°C or lower. When the structure derived from the terpene phenol resin is derived from a terpene phenol resin having a softening point of 90°C or higher and 150°C or lower, the biomass component ratio and pencil hardness can be sufficiently improved. The structure derived from the terpene phenol resin is more preferably derived from a terpene phenol resin having a softening point of 100°C or higher and 145°C or lower. The softening point is a temperature determined by the method specified in JIS K 6910:2007.

[0032] Examples of the structure derived from the terpene phenol resin include the structures shown below.

[0033] (In formula (5), x is an integer from 1 to 10, and y is an integer from 1 to 10.)

[0034] The phenoxy resin of the present invention preferably has a weight average molecular weight (Mw) of 1,000 to 10,000, more preferably 1,500 to 5,000. The weight average molecular weight is measured, for example, as a polystyrene-equivalent value by gel permeation chromatography (GPC).

[0035] The phenoxy resin of the present invention has a high biomass component ratio. Here, the biomass component ratio refers to the proportion of biomass-derived components contained in the phenoxy resin component, and is expressed by the following formula: Biomass component ratio (%) = (mass of biomass-derived components / mass of phenoxy resin component) × 100. If the biomass component ratio is 25% or more, it can be evaluated as having a sufficiently high biomass component ratio.

[0036] (Method for producing phenoxy resin) The method for producing a phenoxy resin of the present invention includes a step of reacting a compound represented by the following formula (3), a compound represented by the following formula (4), and a terpene phenol resin. Specifically, it is preferable to heat the compound represented by the following formula (3) and the terpene phenol resin in the presence of a catalyst, and then react the compound represented by the following formula (4) therewith.

[0037] First, the step of heating the compound represented by the following formula (3) and the terpene phenol resin in the presence of a catalyst (hereinafter also referred to as the heating step) will be described.

[0038] (In formula (3), R is a hydrocarbon group having 10 to 18 carbon atoms, and n is an integer of 2 to 20.)

[0039] (In formula (4), X is a divalent linking group derived from a hydrocarbon and having 1 to 10 carbon atoms.)

[0040] In the method for producing a phenoxy resin of the present invention, a compound represented by the above formula (3) is prepared. The compound represented by the above formula (3) may be commercially available or may be synthesized by the following method.

[0041] As a method for synthesizing the compound represented by the above formula (3), for example, a method of reacting a compound represented by the following formula (6) in the presence of an acid catalyst can be mentioned.

[0042] (In formula (6), R １ is a hydrocarbon group having 10 to 18 carbon atoms.

[0043] In the above formula (6), R １is a hydrocarbon group having 10 to 18 carbon atoms. The hydrocarbon group having 10 to 18 carbon atoms may be linear or branched. Furthermore, the hydrocarbon group having 10 to 18 carbon atoms may be saturated or unsaturated. Of these, the hydrocarbon group having 11 to 17 carbon atoms is preferred, and from the viewpoints of improving the biomass component ratio in the phenoxy resin and cured product of the present invention and suppressing a decrease in pencil hardness of the cured product, a hydrocarbon group having 12 to 16 carbon atoms is more preferred.

[0044] In the above formula (6), R １ From the viewpoint of availability of raw materials, １ and those having a cardanol structure, which is a hydrocarbon group having 15 carbon atoms and 25 to 31 hydrogen atoms.

[0045] As the acid catalyst, known acids can be used, for example, inorganic acids such as sulfuric acid, hydrochloric acid, and nitric acid, and organic acids such as acetic acid, citric acid, propionic acid, oxalic acid, and p-toluenesulfonic acid. Among these, p-toluenesulfonic acid is preferably used from the viewpoints of catalytic activity and solubility in the solution. The content of the acid catalyst is about 0.1 to 4.0 parts by mass per 100 parts by mass of the compound represented by formula (6).

[0046] The reaction temperature when reacting the compound represented by formula (6) in the presence of an acid catalyst is, for example, about 120 to 180°C. The reaction time is, for example, about 1 to 10 hours. The fact that the target compound represented by formula (3) has been obtained can be confirmed, for example, by using gel permeation chromatography (GPC) to confirm a decrease in the peak derived from formula (6) and the distillation of a new component.

[0047] The apparatus used in the reaction (such as a stirring apparatus or reflux apparatus) may be appropriately selected from known apparatuses. After the reaction, the product may be purified by a known method, or may not be purified. Purification by a known method is more preferred.

[0048] The terpene phenol resin can be obtained by copolymerizing the terpene monomer with phenol.

[0049] The softening point of the terpene phenol resin is preferably 90° C. or higher and 150° C. or lower, and more preferably 100° C. or higher and 145° C. or lower. The softening point can be measured by the method described above.

[0050] The terpene phenol resin preferably has the structure of the above-mentioned formula (5). Commercially available terpene phenol resins include, for example, YS Polystar T100, YS Polystar T115, YS Polystar U115, YS Polystar K125, and YS Polystar S145 (all manufactured by Yasuhara Chemical Co., Ltd.).

[0051] The method for producing a phenoxy resin of the present invention preferably includes the heating step.

[0052] In the heating step, the mass ratio of the compound represented by formula (6) to the terpene phenol resin (compound represented by formula (6):terpene phenol resin) is preferably 1:0.2 to 1.0, from the viewpoint of the physical properties of the coating film when cured.

[0053] The heating step is carried out in the presence of a catalyst. An acid catalyst is preferably used as the catalyst. Known acid catalysts can be used, including, for example, inorganic acids such as sulfuric acid, hydrochloric acid, and nitric acid, and organic acids such as acetic acid, citric acid, propionic acid, oxalic acid, and p-toluenesulfonic acid. Among these, p-toluenesulfonic acid is preferably used from the viewpoints of catalytic activity and solubility in a solution.

[0054] The amount of the acid catalyst used varies depending on the type of acid catalyst, but is, for example, about 0.1 to 5.0 parts by mass per 100 parts by mass of the compound represented by formula (6).

[0055] A solvent may be used in the heating step. The solvent is not particularly limited, but preferred examples include water, alcohols such as methanol, ethanol, and 2-propanol, aprotic polar solvents such as dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran, dioxane, methyl ethyl ketone, methyl isobutyl ketone, methylene chloride, and dimethylformamide, aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, chloroform, and carbon tetrachloride. The solvents may be used alone or in combination.

[0056] The amount of the solvent used is, for example, about 30 parts by mass or less per 100 parts by mass of the compound represented by formula (6).

[0057] The reaction temperature in the heating step is, for example, about 60 to 150° C. The reaction time is, for example, about 0.25 to 10 hours.

[0058] The equipment used in the heating step (such as a stirring device or reflux device) may be selected appropriately from known equipment.

[0059] After the heating step, it is preferable to have a step of reacting the compound represented by formula (4). In the step of reacting the compound represented by formula (4), it is preferable to react the compound represented by formula (4) under basic conditions. Thereby, the phenoxy resin of the present invention is obtained.

[0060] In the step of reacting the compound represented by formula (4), the epoxy groups of the compound represented by formula (4) react with the hydroxyl groups of the structure derived from the compound represented by formula (6) or the hydroxyl groups of the structure derived from the terpene phenol resin. The sites where the epoxy groups of the compound represented by formula (4) react may be continuous (blocked) or random.

[0061] In the compound represented by formula (4), X is a divalent linking group derived from hydrocarbon and having 1 to 10 carbon atoms. The divalent linking group having 1 to 10 carbon atoms may be linear or branched, or may have a cyclic structure. Specific examples include alkylene groups, alkenylene groups, alkynylene groups, and cycloalkylidene groups. Among these, from the viewpoint of availability, alkylene groups having 3 to 7 carbon atoms are preferred. The divalent linking group having 1 to 10 carbon atoms may contain a non-carbon molecule such as an oxygen atom or a nitrogen atom in the linking group. The divalent linking group having 1 to 10 carbon atoms may have a substituent, and examples of the substituent include an alkyl group, an alkoxy group, a hydroxyl group, an alkoxy-substituted alkyl group, and a carboxyl group.

[0062] In the above formula (4), O １ may be in the ortho, meta or para position relative to X, O ２ may be in any of the ortho, meta, and para positions relative to X. However, from the viewpoint of availability, O １ and O ２ is preferably in the para position relative to X.

[0063] In the step of reacting the compound represented by the formula (4), the amount of the compound represented by the formula (4) used is, for example, preferably such that the mass ratio of the compound represented by the formula (6) used in the heating step to the compound represented by the formula (4) (compound represented by the formula (6) : compound represented by the formula (4)) is 1:0.7 to 5.0, from the viewpoint of the physical properties of the coating film when cured.

[0064] In the step of reacting the compound represented by formula (4), a base may be added to the reaction solution in the heating step.

[0065] The base is not particularly limited, but examples thereof include alkali metal hydrides, alkaline earth metal hydrides, alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates, alkaline earth metal carbonates, alkali metal hydrogencarbonates, alkali metal alkoxides, alkaline earth metal alkoxides, alkali metal fluorides, amines, organic phosphorus compounds, etc. The amount of the base used varies depending on the type of base, but is, for example, about 0.1 to 2.0 parts by mass per 100 parts by mass of the compound represented by formula (4).

[0066] In the step of reacting the compound represented by formula (4), a solvent may be used. The solvent is not particularly limited, but for example, the same solvent as in the heating step may be used. The solvent may be used alone or in combination with a plurality of types. The amount of the solvent used is, for example, about 30 parts by mass or less per 100 parts by mass of the compound represented by formula (6).

[0067] The reaction temperature in the step of reacting the compound represented by formula (4) is, for example, about 60 to 120°C. The reaction time is, for example, about 30 minutes to 10 hours. The desired phenoxy resin can be confirmed by, for example, using gel permeation chromatography (GPC), by confirming a decrease in the peak derived from the raw material (for example, the compound represented by formula (4)) and the distillation of new components.

[0068] The apparatus used in the reaction (such as a stirring apparatus or reflux apparatus) may be appropriately selected from known apparatuses. After the reaction, the product may be purified by a known method, or may not be purified. Purification by a known method is more preferred.

[0069] (Composition) The composition of the present invention includes the phenoxy resin of the present invention. Because the composition of the present invention includes the phenoxy resin, it is possible to obtain a cured product having a high biomass component ratio and excellent pencil hardness.

[0070] The composition of the present invention preferably further comprises a curing agent.

[0071] Examples of the curing agent include amine curing agents, phenol curing agents, acid anhydride curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, blocked isocyanate curing agents, etc. The curing agents may be used alone or in combination of two or more.

[0072] The content of the curing agent is preferably 20 to 90 parts by mass per 100 parts by mass of the phenoxy resin.

[0073] From the viewpoint of shortening the curing time, the composition of the present invention preferably further contains a curing catalyst.

[0074] Examples of the curing catalyst include tertiary amine compounds such as benzyldimethylamine (BDMA) and 2,4,6-trisdimethylaminomethylphenol, and imidazole compounds such as 2-methylimidazole and 2-ethyl-4-methylimidazole. The curing catalysts may be used alone or in combination of two or more.

[0075] The content of the curing catalyst is preferably 0.1 to 2.0 parts by mass per 100 parts by mass of the phenoxy resin.

[0076] The composition of the present invention may further comprise a solvent.

[0077] Preferred examples of the solvent include water, alcohols such as methanol, ethanol, and isopropyl alcohol, aprotic polar solvents such as dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran, dioxane, methyl ethyl ketone, methyl isobutyl ketone, methylene chloride, and dimethylformamide, aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, chloroform, and carbon tetrachloride, but are not limited to these. The solvents may be used alone or in combination.

[0078] The composition of the present invention may further comprise additives.

[0079] The additives include photopolymerization initiators, phosphorus-containing compounds, binder resins, inorganic fillers, etc. These may be appropriately selected from known additives.

[0080] (Cured Product) The cured product of the present invention is obtained by curing the phenoxy resin of the present invention and / or the composition of the present invention. Because the cured product of the present invention contains the phenoxy resin of the present invention, it is possible to obtain a cured product with a high biomass component ratio and excellent pencil hardness.

[0081] The cured product of the present invention can be obtained by curing the phenoxy resin of the present invention and / or the composition of the present invention using a conventionally known method. For example, the phenoxy resin of the present invention, the curing agent, and the curing catalyst are thoroughly mixed until homogeneous using an extruder, kneader, roll, or the like as necessary to prepare a composition, which is then applied to a substrate by a known method and allowed to stand at 20 to 40°C for 12 to 48 hours, thereby obtaining the cured product of the present invention. The temperature and time during standing are not limited to the above ranges and may be selected appropriately depending on the type of curing agent, etc. The composition may contain additives as needed.

[0082] The cured product of the present invention has high pencil hardness. The pencil hardness can be evaluated, for example, by preparing a cured product (100 mm long x 100 mm wide, 200 μm thick) on a glass plate (100 mm long x 100 mm wide) and measuring it according to JIS K 5600-5-4:1999. If the pencil hardness is F or higher, it can be evaluated as having sufficient pencil hardness. The pencil hardness is more preferably H or higher.

[0083] The cured product used for pencil hardness testing is prepared, for example, by the following method. The amounts of curing agent and catalyst used are adjusted depending on the phenoxy resin, etc. 100 parts by mass of phenoxy resin are taken, and 51 parts by mass of curing agent (ST11, manufactured by Mitsubishi Chemical Corporation) and 1 part by mass of 2,4,6-trisdimethylaminomethylphenol (manufactured by Tokyo Chemical Industry Co., Ltd.) are added and mixed to obtain a composition. The composition is applied to a glass plate (100 mm long x 100 mm wide) and left to stand at room temperature for 3 days to prepare a test cured product (100 mm long x 100 mm wide, 200 μm thick).

[0084] The cured product of the present invention has a high biomass component ratio. The biomass component ratio of the cured product refers to the proportion of biomass-derived components contained in the cured product, and is expressed by the following formula: Biomass component ratio (%) = [mass of biomass-derived components / (total mass of phenoxy resin component + curing agent + curing catalyst + solvent + additives)] × 100 A biomass component ratio of 15% or more can be evaluated as being sufficiently high.

[0085] The present specification discloses the following:

[0086] Disclosure (1) is a phenoxy resin containing a structure represented by the above formula (1), a structure represented by the above formula (2), and a structure derived from a terpene phenol resin. Disclosure (2) is a phenoxy resin according to Disclosure (1), in which R in Formulas (1) and (2) is a hydrocarbon group having 12 to 16 carbon atoms. Disclosure (3) is a phenoxy resin according to Disclosure (1) or (2), in which Formula (1) is derived from cardanol. Disclosure (4) is a phenoxy resin according to any one of Disclosures (1) to (3), in which the structure derived from the terpene phenol resin is derived from a terpene phenol resin having a softening point of 90°C or higher and 150°C or lower. Disclosure (5) is a composition containing the phenoxy resin according to any one of Disclosures (1) to (4). Disclosure (6) is a composition according to Disclosure (5), further containing a curing agent. Disclosure (7) is a composition according to Disclosure (5) or (6), further containing a curing catalyst. The present disclosure (8) is a cured product obtained by curing the phenoxy resin according to any one of the present disclosures (1) to (4) and / or the composition according to any one of the present disclosures (5) to (7). The present disclosure (9) is a method for producing the phenoxy resin according to any one of the present disclosures (1) to (4), the method comprising the step of reacting a compound represented by formula (3) above, a compound represented by formula (4) above, and a terpene phenol resin.

[0087] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass."

[0088] Example 1 100 parts by mass of purified cardanol was weighed into a flask equipped with a stirrer, a reflux condenser, and a stirring device while purging with nitrogen. 40 parts by mass of YS Polystar T100 (manufactured by Yasuhara Chemical Co., Ltd., softening point 100°C) and 3.1 parts by mass of p-toluenesulfonic acid monohydrate were added to prepare a reaction solution. The reaction solution was then heated to 100°C and stirred for 4 hours. 19 parts by mass of aqueous sodium hydroxide solution (1.2 parts by mass of sodium hydroxide dissolved in 17.8 parts by mass of ion-exchanged water) was added to the reaction solution, and the mixture was stirred for 30 minutes while cooling to 75°C. Subsequently, 260 parts by mass of bisphenol A epoxy resin jER-828 (manufactured by Mitsubishi Chemical Corporation) was added, and the mixture was stirred at 75°C for 1 hour. The reaction temperature was returned to room temperature, and the aqueous layer was extracted three times with ethyl acetate. The organic layer was then dehydrated with sodium sulfate. The sodium sulfate was then removed by filtration, and the solvent was distilled off using an evaporator to obtain a phenoxy resin containing the structure represented by formula (1), the structure represented by formula (2), and a structure derived from the terpene phenol resin. Gel permeation chromatography (GPC) confirmed a decrease in the peak derived from the bisphenol A epoxy resin and the distillation of new high molecular weight components, confirming that the desired phenoxy resin had been obtained. The biomass component ratio of this phenoxy resin was 30.5%. The biomass component ratio was calculated using the method described herein.

[0089] Example 2 A phenoxy resin was synthesized in the same manner as in Example 1, except that YS Polyster T100 was replaced with YS Polyster T115 (manufactured by Yasuhara Chemical Co., Ltd., softening point 115°C) and that the mixture was temporarily heated to 130°C immediately after addition and stirred for 30 minutes to dissolve the YS Polyster T115. The biomass component ratio of this phenoxy resin was 31.0%.

[0090] (Example 3) A phenoxy resin was synthesized in the same manner as in Example 1, except that YS Polystar T100 was replaced with YS Polystar U115 (manufactured by Yasuhara Chemical Co., Ltd., softening point 115°C) and that the mixture was temporarily heated to 130°C immediately after addition and stirred for 30 minutes to dissolve the YS Polystar U115. The biomass component ratio of this phenoxy resin was 32.0%.

[0091] Example 4 A phenoxy resin was synthesized in the same manner as in Example 1, except that YS Polystar T100 was replaced with YS Polystar K125 (manufactured by Yasuhara Chemical Co., Ltd., softening point 125°C) and that the mixture was temporarily heated to 130°C immediately after addition and stirred for 30 minutes in order to dissolve the YS Polystar K125. The biomass component ratio of this phenoxy resin was 29.5%.

[0092] Example 5 A phenoxy resin was synthesized in the same manner as in Example 1, except that YS Polyster T100 was replaced with YS Polyster S145 (manufactured by Yasuhara Chemical Co., Ltd., softening point 145°C) and that the mixture was temporarily heated to 150°C immediately after addition and stirred for 30 minutes in order to dissolve the YS Polyster S145. The biomass component ratio of this phenoxy resin was 31.5%.

[0093] Comparative Example 1 Bisphenol A type epoxy resin jER-828 (manufactured by Mitsubishi Chemical Corporation) was prepared. The biomass component ratio of this epoxy resin was 0.0%.

[0094] Comparative Example 2 Synthesis of Compound Represented by Formula (3) 100 parts by mass of purified cardanol was weighed into a flask equipped with a stirrer, a reflux condenser, and a stirring device while purging with nitrogen, and 0.8 parts by mass of p-toluenesulfonic acid monohydrate was added to prepare a reaction solution. The reaction solution was then heated to 150°C and stirred for 3 hours. The reaction temperature was returned to room temperature, and the solution was neutralized with aqueous sodium hydroxide. The aqueous layer was extracted three times with ethyl acetate, and the organic layer was dehydrated with sodium sulfate. The sodium sulfate was then removed by filtration, and the solvent was distilled off using an evaporator. The resulting crude product was heated to 300°C and stirred under reduced pressure for 3 hours to remove the distillate components, yielding a compound represented by Formula (3) (in Formula (3), R is a hydrocarbon group having 15 carbon atoms). Gel permeation chromatography (GPC) confirmed the decrease in the peak attributable to cardanol and the distillation of new high-molecular-weight components, confirming the production of the compound represented by Formula (3).

[0095] [Synthesis of Compound Represented by Formula (7)] 100 parts by mass of the compound represented by Formula (3) was weighed into a flask equipped with a stirrer, a reflux condenser, and a stirring device while purging with nitrogen. 9 parts by mass of methanol, 2.5 parts by mass of water, 134 parts by mass of epichlorohydrin, and 29 parts by mass of sodium hydroxide were added, and the mixture was stirred at 75°C for 3 hours. The reaction temperature was returned to room temperature, and solid components were removed by filtration. The solvent and epichlorohydrin were then distilled off using an evaporator. The resulting reaction solution was extracted three times with ethyl acetate, and the organic layer was dehydrated with sodium sulfate. The sodium sulfate was then removed by filtration, and the solvent was distilled off using an evaporator, thereby synthesizing an epoxy resin represented by Formula (7). The infrared absorption spectrum of the obtained epoxy resin was measured, revealing a peak at 910 cm －１ The appearance of a peak derived from an epoxy group in the vicinity of 3100 to 3600 cm －１ The disappearance of the peaks derived from the hydroxyl groups was confirmed, and it was confirmed that an epoxy resin represented by the following formula (7) was obtained. The biomass component ratio of this epoxy resin was 76.6%.

[0096] (In formula (7), R is a hydrocarbon group having 15 carbon atoms, and z is an integer of 2 to 20.)

[0097] Comparative Example 3 100 parts by mass of the compound represented by formula (3) was weighed into a flask equipped with a stirrer, a reflux condenser, and a stirring device while purging with nitrogen. 100 parts by mass of bisphenol A epoxy resin jER-828 (manufactured by Mitsubishi Chemical Corporation), 1.3 parts by mass of sodium hydroxide, 18 parts by mass of methanol, and 5 parts by mass of water were added to prepare a reaction solution. The reaction solution was then heated to 75°C and stirred for 3 hours under reflux. The reaction temperature was returned to room temperature, and the aqueous layer was extracted three times with toluene. The organic layer was then dehydrated with sodium sulfate. The sodium sulfate was then removed by filtration, and the solvent was distilled off using an evaporator to obtain a phenoxy resin containing a structure represented by formula (1) (in formula (1), R is a hydrocarbon group having 15 carbon atoms) and a structure represented by formula (2) (in formula (2), X is a linking group having 3 carbon atoms, and R is a hydrocarbon group having 15 carbon atoms). Gel permeation chromatography (GPC) confirmed the decrease in the peak derived from bisphenol A epoxy resin and the distillation of new high molecular weight components, confirming that the target phenoxy resin had been obtained. The biomass component ratio of this phenoxy resin was 50.0%.

[0098] (Comparative Example 4) A phenoxy resin was synthesized in the same manner as in Comparative Example 3, except that the amount of the compound represented by formula (3) was changed to 60 parts by mass and the amount of bisphenol A-type epoxy resin jER-828 was changed to 140 parts by mass. The biomass component ratio of this phenoxy resin was 30.0%.

[0099] (Comparative Example 5) A phenoxy resin was synthesized in the same manner as in Comparative Example 3, except that the amount of the compound represented by formula (3) was changed to 20 parts by mass and the amount of bisphenol A-type epoxy resin jER-828 was changed to 180 parts by mass. The biomass component ratio of this phenoxy resin was 10.0%.

[0100] [Preparation of Test Cured Product] 100 parts by mass of the phenoxy resin synthesized in Example 1 was taken, and 51 parts by mass of a curing agent (ST11, manufactured by Mitsubishi Chemical Corporation) and 1 part by mass of 2,4,6-trisdimethylaminomethylphenol (manufactured by Tokyo Chemical Industry Co., Ltd.) were added and mixed to obtain a composition. The composition was applied to a glass plate (100 mm long x 100 mm wide) and allowed to stand at room temperature for 3 days to prepare a test cured product (100 mm long x 100 mm wide, 200 μm thick). The biomass component ratio of this test cured product was 20.1%. The biomass component ratio of the cured product was calculated using the method described herein.

[0101] As in Example 1, compositions were obtained by mixing the resins obtained in Examples 2 to 5 and Comparative Examples 1 to 5 in the parts by mass shown in Table 1. Test cured products were prepared from these compositions in the same manner as in Example 1. The biomass component ratios of these test cured products are also shown in Table 1. In Comparative Example 2, the resin and curing agent were not compatible, and a composition could not be obtained.

[0102] <Compatibility with Curing Agent> Resin, curing agent, and catalyst were mixed in the parts by mass shown in Table 1, and after leaving to stand for 5 minutes, the appearance was observed and evaluated according to the following criteria. The results are shown in Table 1. Good: Resin and curing agent are uniformly mixed. Poor: Resin and curing agent are not uniformly mixed and separate.

[0103] <Pencil Hardness> The pencil hardness of the obtained test cured products was measured in accordance with JIS K 5600-5-4: 1999. The results are shown in Table 1.

[0104]

[0105] It has been confirmed that the phenoxy resin having a structure derived from the terpene phenol resin of the present invention has a biomass component ratio of 25% or more, a high biomass component ratio of 15% or more, and can give a cured product having an excellent hardness of pencil hardness F or more.

[0106] The present invention can provide a phenoxy resin that has a high biomass component ratio and can give a cured product with high pencil hardness.

Claims

1. A phenoxy resin comprising a structure represented by the following formula (1), a structure represented by the following formula (2), and a structure derived from a terpene phenol resin. (In formula (1), R is a hydrocarbon group having 10 to 18 carbon atoms, and l is an integer from 1 to 10.) (In formula (2), X is a divalent linking group having 1 to 10 carbon atoms derived from a hydrocarbon, R is a hydrocarbon group having 10 to 18 carbon atoms, and m is an integer of 1 to 10.) 2. The phenoxy resin according to claim 1, wherein in the formulas (1) and (2), R is a hydrocarbon group having 12 to 16 carbon atoms.

3. The phenoxy resin according to claim 1 or 2, wherein the formula (1) is derived from cardanol.

4. A phenoxy resin according to claim 1 or 2, wherein the structure derived from the terpene phenol resin is derived from a terpene phenol resin having a softening point of 90°C or higher and 150°C or lower.

5. A composition comprising the phenoxy resin of claim 1.

6. The composition of claim 5 further comprising a curing agent.

7. The composition of claim 5 further comprising a curing catalyst.

8. A cured product obtained by curing the phenoxy resin according to claim 1 and / or the composition according to claim 5.

9. A method for producing the phenoxy resin according to claim 1 or 2, comprising the step of reacting a compound represented by the following formula (3), a compound represented by the following formula (4), and a terpene phenol resin. (In formula (3), R is a hydrocarbon group having 10 to 18 carbon atoms, and n is an integer from 2 to 20.) (In formula (4), X is a divalent linking group having 1 to 10 carbon atoms derived from a hydrocarbon.)

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