Curable composition

Abstract

The present invention addresses the problem of providing: a curable composition which can be cured under low-temperature conditions and in which a cured product has improved heat resistance; a cured product obtained by curing the curable composition; a curing agent for a resole phenolic resin; and a binder containing the curable composition. As a solution, provided is a curable composition characterized by containing the following component (A) and the following component (B): component (A): a resole phenolic resin; component (B): a composition containing a component (B1) comprising the following compound (1), compound (2), and compound (3), the total amount of the component (B1) being in the range of 40% by area to 70% by area (inclusive) with respect to the total amount of all the components detected by gel permeation chromatography measurement using a differential refractometer as a detector. [chemical] # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a curable composition, a cured product obtained by curing the curable composition, a curing agent for a resol type phenolic resin, and an adhesive containing the curable composition. Background Art

[0002] It is known that phenolic resin is a polymer obtained from phenol and formaldehyde as raw materials, and can be classified into two types: thermoplastic novolac type phenolic resin obtained using an acid catalyst and thermosetting resol type phenolic resin obtained using an alkali catalyst. Any phenolic resin has excellent characteristics of heat resistance, mechanical strength, chemical resistance or electrical insulation, and is therefore widely used in various fields such as automotive parts, thermal insulation materials, corrosion resistant materials, adhesives, etc. In particular, phenolic resins with high heat resistance or mechanical strength have attracted attention as metal substitutes in recent years.

[0003] The resol type phenolic resin has a methylol group as a functional group that reacts by heat, and the methylol group condenses with hydrogen and methylol groups of the aromatic ring by heating to form crosslinks. This crosslinking reaction proceeds everywhere, so that the resol type phenolic resin constructs a random three-dimensional network to form a cured product.

[0004] The curing of a resol-type phenolic resin that does not contain any curing accelerator is inferior to the curing of a novolac-type phenolic resin in curing at low temperatures (150 to 200° C.). Therefore, the curing at low temperatures is insufficient, and there is a problem that a cured product with excellent heat resistance cannot be obtained. Although this solution has been proposed (for example, Patent Document 1, etc.), it has not been fully solved.

[0005] Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2002-105282 Summary of the invention The present invention aims to provide a curable composition which can be cured under low temperature conditions and whose cured product has improved heat resistance, a cured product obtained by curing the curable composition, a curing agent for resol type phenolic resin, and an adhesive containing the curable composition.

[0006] The present inventors have studied a method for obtaining a cured product having improved heat resistance by adding a curing agent to a resol type phenolic resin to increase the reactivity of methylol groups remaining without reacting by heating alone.

[0007] Specifically, the inventors believed that by using a relatively soft curing agent with a low melting point, the reactivity would be improved by uniform mixing with the resol type phenolic resin, and therefore selected a curing agent having a bis(hydroxyphenyl)methane skeleton. As a result, it was found that the curing agent could be cured under low temperature conditions and the heat resistance of the cured product was improved, thereby completing the present invention.

[0008] The present invention is as follows.

[0009] 1. A curable composition, characterized in that it contains the following component (A) and the following component (B), Ingredient (A): resol type phenolic resin; Component (B): A composition comprising a component (B1) consisting of the following compound (1), compound (2) and compound (3), wherein the total amount of component (B1) is in the range of 40 area % to 70 area % relative to the total amount of all components detected by gel permeation chromatography using a differential refractometer as a detector, [Chemistry 1] .

[0010] 2. A cured product, characterized in that it is obtained by curing the curable composition described in 1.

[0011] 3. A resol type phenolic resin curing agent, characterized in that it contains the following component (B), Component (B): A composition comprising a component (B1) consisting of the following compound (1), compound (2) and compound (3), wherein the total amount of component (B1) is in the range of 40 area % to 70 area % relative to the total amount of all components detected by gel permeation chromatography using a differential refractometer as a detector, [Chemistry 2] .

[0012] 4. An adhesive, characterized in that it contains the curable composition described in 1.

[0013] The curable composition of the present invention can be cured at a low temperature compared to conventionally known resol-type phenolic resins, so the temperature of the curable resin during the molding process can be lowered, and efficiency can be improved by shortening the heating and cooling time or saving energy. In addition, it can also be used for heat-sensitive materials (substrates), which is very useful.

[0014] Furthermore, the cured product of the compound of the present invention has significantly improved heat resistance compared to the cured product of the conventionally known resol-type phenolic resin cured only with a resol phenolic resin, and is therefore very useful as a material having excellent stability and reliability at high temperatures.

[0015] The curable composition of the present invention or the cured product obtained by curing the curable composition can be suitably used as a resin raw material such as a varnish that can be applied to various substrates, a prepreg impregnated with a varnish, a printed circuit board, a sealant for electronic parts, electric and electronic molded parts, automobile parts, laminated materials, coatings, and anti-corrosion inks. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a graph showing differential scanning calorimetry (DSC) curves of Example 5 (solid line) and Comparative Example 10 (dashed line). DETAILED DESCRIPTION

[0017] <Ingredients (A)> The component (A) contained in the curable composition of the present invention is a resol type phenolic resin. Examples of the resol type phenolic resin used in the present invention include those obtained by reacting phenolic compounds such as phenol, cresol, and bisphenol A with aldehyde compounds such as formaldehyde, paraformaldehyde, and glyoxal in the presence of a base catalyst. The base catalyst includes inorganic oxides or hydroxides of alkali metals and alkaline earth metals, and organic oxides such as amines and ammonia.

[0018] The resol type phenolic resin as component (A) of the present invention is preferably a product obtained by reacting a mononuclear phenolic compound such as phenol or cresol with an aldehyde compound, more preferably a product obtained by reacting phenol or cresol with an aldehyde compound, and particularly preferably a product obtained by reacting phenol with an aldehyde compound.

[0019] The weight average molecular weight (Mw) of the component (A) is preferably 4,000 or more, more preferably 8,000 or more, further preferably 12,000 or more, and particularly preferably 15,000 or more, and the upper limit is preferably 50,000 or less, more preferably 40,000 or less, further preferably 30,000 or less, and particularly preferably 20,000 or less. In addition, the ratio (Mw / Mn) of the weight average molecular weight (Mw) / number average molecular weight (Mn) of the component (A) is preferably 3.0 or more, more preferably 6.0 or more, further preferably 10.0 or more, and particularly preferably 15.0 or more, and the upper limit is preferably 20.0 or less, more preferably 19.0 or less, further preferably 18.0 or less, and particularly preferably 17.0 or less.

[0020] <Ingredient (B)> The component (B) contained in the curable composition of the present invention or the component (B) contained in the curing agent for a resol type phenolic resin of the present invention is a substance for curing the resol type phenolic resin of the component (A) of the present invention, and is a composition containing a component (B1) consisting of the following compound (1), compound (2) and compound (3), wherein the total amount of the component (B1) is in the range of 40 area % or more and 70 area % or less relative to the total amount of all components detected by gel permeation chromatography using a differential refractometer as a detector.

[0021] [Chemistry 3]

[0022] The component (B) in the present invention preferably contains the component (B1) composed of the above-mentioned compound (1), compound (2) and compound (3) in an amount of 50 area % to 67 area % in total as measured by the gel permeation chromatography, and more preferably contains the component (B1) in an amount of 53 area % to 65 area % in total.

[0023] In the present invention, the component (B1) comprising compound (1), compound (2) and compound (3) preferably contains compound (1) and compound (2) in an area ratio of 35 / 65 to 55 / 45, more preferably in an area ratio of 40 / 60 to 50 / 50, as measured by high performance liquid chromatography at a wavelength of 280 nm using an ultraviolet absorption spectrometer as a detector.

[0024] Furthermore, as measured by high performance liquid chromatography using an ultraviolet absorption spectrometer as a detector at a wavelength of 280 nm, component (B1) in the present invention preferably contains the total of compound (1) and compound (2) and compound (3) in an area ratio of 95 / 5 to 80 / 20 (compound (1) + compound (2) / compound (3), and more preferably contains the compound (3) in an area ratio of 90 / 10 to 85 / 15.

[0025] The component (B) in the present invention is obtained by reacting phenol and formaldehyde in the presence of an acid catalyst, wherein the amount of phenol used is set to 3 to 8 mol relative to 1 mol of formaldehyde, and removing unreacted phenol from the resulting reaction mixture by distillation or the like. After the reaction, a neutralization treatment or a water washing operation for removing a neutralization salt may be performed as required. The amount of phenol used in the reaction is preferably in the range of 3.7 to 7.2 mol relative to 1 mol of formaldehyde, and more preferably in the range of 4.3 to 6.7 mol.

[0026] The acid catalyst is preferably oxalic acid. When an oxalic acid catalyst is used, it is preferred to produce component (B) by directly removing low-boiling substances such as phenol by distillation from the obtained reaction mixture. The amount of oxalic acid used is preferably set to a concentration range of 1 to 0.01% by weight, more preferably 0.5 to 0.05% by weight, relative to the total amount of phenol and formaldehyde used in the reaction. The reaction temperature is preferably 60 to 100° C., more preferably 70 to 90° C.

[0027] The component (B) of the present invention prepared by this production method contains, in addition to the component (B1), a polycondensate of phenol and formaldehyde other than the component (B1). The polycondensate preferably contains the component (B2) described below, more preferably contains the component (B2) and the component (B3), and further preferably contains the component (B2), the component (B3) and the component (B4). The components (B2) to (B4) are described in detail below.

[0028] <Ingredient (B2)> The component (B2) contained in the component (B) of the present invention is a group of compounds represented by the following general formula (b2) in which the para-position or para-position of the hydroxyl group in the above-mentioned compounds (1), (2) and (3) is substituted with a (4-hydroxyphenyl)methyl group or a (2-hydroxyphenyl)methyl group.

[0029] [Chemistry 4]

[0030] (In the formula, the bonding position of the methylene group is para or ortho to the hydroxyl group.) Examples of the compound represented by the general formula (b2) include the following compounds.

[0031] [Chemistry 5]

[0032] The content of the component (B2) contained in the component (B) of the present invention is preferably 20 to 30 area %, more preferably 22 to 28 area %, and further preferably 24 to 26 area % relative to the total amount of all components detected by gel permeation chromatography using a differential refractometer as a detector.

[0033] <Component (B3), component (B4)> The component (B3) which may be contained in the component (B) of the present invention is composed of a group of compounds having a structure in which a (4-hydroxyphenyl)methyl group or a (2-hydroxyphenyl)methyl group is substituted at the para-position or ortho-position of the hydroxyl group of the compound represented by the general formula (b2).

[0034] Furthermore, the component (B4) that may be contained in the component (B) of the present invention is composed of the following compound groups: a compound group having a structure in which a (4-hydroxyphenyl)methyl group or a (2-hydroxyphenyl)methyl group is substituted at the para-position or para-position of the hydroxyl group in the compound contained in the component (B3); and a compound group having a structure in which a substitution reaction with a (4-hydroxyphenyl)methyl group or a (2-hydroxyphenyl)methyl group is repeated one or more times in the obtained compound.

[0035] The component (B) of the present invention may contain a component (B3) and / or a component (B4) in addition to the component (B1) and the component (B2).

[0036] When the component (B) of the present invention contains the component (B3) and the component (B4), the content of the component (B3) is preferably in the range of 18 to 28 area %, more preferably in the range of 20 to 26 area %, further preferably in the range of 21 to 25 area %, and particularly preferably in the range of 22 to 24.5 area %, relative to the total content (area %) of the component (B2), the component (B3) and the component (B4) detected by gel permeation chromatography using a differential refractometer as a detector.

[0037] <Polystyrene equivalent molecular weight of components (B2) and (B3)> The polystyrene equivalent molecular weights of components (B2) and (B3) measured by gel permeation chromatography (GPC) are preferably in the range of 440 to 490, more preferably in the range of 450 to 480, and preferably in the range of 580 to 630, more preferably in the range of 590 to 620 for component (B2).

[0038] <Curable composition of the present invention> The curable composition of the present invention contains a resol-type phenolic resin as a component (A) and a component (B), wherein the component (B) as a curing agent is contained in an amount of preferably 1 to 25 parts by weight, more preferably 5 to 20 parts by weight, and even more preferably 8 to 13 parts by weight, based on 100 parts by weight of the resol-type phenolic resin (A).

[0039] The curable composition of the present invention is preferably obtained by mixing the resol type phenolic resin of the component (A) and the component (B) under a temperature environment of about 90° C. for about 10 minutes.

[0040] The curable composition of the present invention may contain, in addition to the resol type phenolic resin of component (A) and component (B), inorganic fillers such as silicon oxide, aluminum oxide, magnesium oxide, boron nitride, aluminum nitride, silicon nitride, silicon carbide, hexagonal boron nitride, or reinforcing fibers such as carbon fiber, glass fiber, organic fiber, boron fiber, steel fiber, and aramid fiber.

[0041] In the curable composition of the present invention, the amount of the above materials that can be used together is preferably in the range of 0.01 to 100 parts by weight per 1 part by weight of the total of the resol type phenolic resin of component (A) and component (B).

[0042] As for the curable composition of the present invention, if the composition contains water or residual solvent, bubbles will be generated during curing, so in order to avoid this situation, it is preferred to perform vacuum degassing as a pretreatment. The temperature of the vacuum degassing treatment is not particularly limited as long as it is a temperature that makes the curable composition of the present invention molten, but it is preferably carried out with 90°C as the upper limit because it will not be cured and is easy to degas. The pressure of the vacuum degassing treatment is not particularly limited, but low pressure (high degree of decompression) is preferred, and it can be carried out in any one of the air or inert gas environments such as nitrogen. The vacuum degassing treatment is preferably carried out until bubbles cannot be confirmed by visual observation.

[0043] <Cured product obtained by curing the curable composition of the present invention> The cured product of the present invention can be obtained by curing the curable composition of the present invention containing the resol-type phenolic resin as the component (A) and the component (B).

[0044] Examples of methods for producing the cured product of the present invention include: a method of curing the cured product by heating it to a predetermined temperature; a method of melting the cured product by heating it and injecting it into a mold, and then further heating the mold to cure the cured product; a method of curing the cured product by injecting the molten product into a preheated mold, etc.

[0045] The curing temperature of the curable composition of the present invention is generally within a range of 140 to 220°C, preferably within a range of 150 to 200°C, more preferably within a range of 160 to 190°C, and further preferably within a range of 165 to 185°C.

[0046] When curing is carried out within this temperature range, the reaction time is about 5 to 30 minutes.

[0047] The curable composition of the present invention has a lower curing temperature than the conventionally known resol-type phenolic resin, and thus can improve efficiency by shortening the heating and cooling time or saving energy in the curable resin molding process. In addition, it can also be used for heat-sensitive materials (substrates), and is therefore very useful. Furthermore, its cured product has significantly improved heat resistance compared to conventionally known cured products, and is therefore a material with excellent stability or reliability at high temperatures, and is therefore very useful.

[0048] <Binder> As described above, the curable composition of the present invention can proceed and complete the curing reaction at a lower temperature than conventional ones, and therefore is suitable for use as an adhesive, a sealant, a coating material, a sizing agent, and the like.

[0049] Furthermore, the cured product of the curable composition of the present invention can be suitably used in fields requiring ultra-high heat resistance and excellent dielectric properties (eg, electronic information equipment, home appliances, automobiles, precision machinery, aircraft, and space industry equipment).

[0050] Example The present invention is further specifically described below by way of examples.

[0051] <Analysis method> 1. Gel Permeation Chromatography (GPC) for analysis of component concentrations (B1) to (B4) Components (B1) to (B4) contained in component (B) of the present invention are determined by the numerical values ​​of the area percentages of all components detected by this analysis.

[0052] Measuring device: HLC-8320GPC manufactured by Tosoh Corporation Detector: RI detector Chromatographic columns: TSKgel guardcolumn SuperMP (HZ) -N, TSKgel SuperMultiporeHZ-N × 3 pieces (4.6mmI.D. × 15cm, microparticle filler: 3~6μm) [Measurement conditions] Flow rate: 0.35mL / min. Mobile phase: tetrahydrofuran Column temperature: 40°C Sample concentration: 0.5wt% (tetrahydrofuran solution) Injection volume: 10 μL [Molecular weight determination] Molecular weights were calculated from polyethylene standards.

[0053] 2. High performance liquid chromatography (HPLC) Measuring device: High performance liquid chromatography (UFLC) (manufactured by Shimadzu Corporation) Pump: LC-20AD Column oven: CTO-20A Detector: SPD-20A (UFLC), flow cell length 5 mm Chromatographic column: HALO-C18 (Chromatographic column 3.0×75 mm, particle size 2.7 μm, manufactured by Advanced Materials Technology Co., Ltd.) [Measurement conditions] Incubator temperature: 50℃ Flow rate: 0.8mL / min. Mobile phase: (A) 0.2 vol% acetic acid aqueous solution, (B) methanol Gradient conditions: (B) Volume % (time elapsed from the start of analysis) 10% (0 min) → 10% (2.6 min) → 100% (13.6 min) → 100% (25.0 min) Detection wavelength: 280nm Sample concentration: 2.0 mg / mL (methanol solution) Sample injection volume: 5μL 3. Thermogravimetric analysis (TGA) Device: SII Nanotechnology differential thermal and thermogravimetric simultaneous measurement device (TG / DTA6200) 5.0 mg to 7.0 mg of the cured product was placed in an aluminum pan for DSC, and the temperature was raised from 100° C. to 600° C. at a heating rate of 10° C. / min in a nitrogen atmosphere.

[0054] The 5% weight loss temperature (Td5%) of the cured product was measured during the temperature increase process.

[0055] 4. Gel Permeation Chromatography for Resol Analysis: GPC Measuring device: High performance liquid chromatography analyzer (Chromaster 5110) manufactured by Hitachi High-Technologies Corporation Column oven: Chromaster 5310 (manufactured by Hitachi High-Technologies Corporation) UV detector: Chromaster 5410 (manufactured by Hitachi High-Technologies Corporation) Chromatographic column: Shodex styrene-divinylbenzene copolymer packed column (LF-804 x 2 pieces) Others: Degassing unit (DG660B) manufactured by GL Sciences [Measurement conditions] Flow rate: 1.0mL / min. Mobile phase: tetrahydrofuran Column temperature: 25°C Measurement wavelength: 270nm Sample concentration: 5mg / THF4~5mL Injection volume: 20 μL The converted molecular weight was calculated based on a polystyrene standard.

[0056] 5. Differential Scanning Calorimetry (DSC) The curable composition was precisely weighed in an aluminum pan, and measured using a differential scanning calorimeter (DSC-7020, manufactured by Hitachi High-Technologies Corporation) under the following conditions with an empty aluminum pan as a control.

[0057] (Measurement conditions) Heating rate: 10℃ / min. Measuring temperature range: 30~200℃ Measurement environment: open, nitrogen 50mL / min. Sample amount: 3mg±1mg <Production Example 1> In a four-necked flask equipped with a condenser, a stirrer, and a thermometer, 330.4 g (3.51 mol) of phenol and 2.26 g of a 10% oxalic acid aqueous solution were placed, and after the temperature was raised to 70°C, 122.0 g (1.42 mol) of a 35% formaldehyde aqueous solution was added within 5 minutes. After the addition was completed, the temperature was raised to 90°C and stirring was continued for 6.5 hours. After the reaction was completed, distillation was started under the conditions of 80°C and 47 kPa. After the temperature was raised to 145°C (3 kPa) for 3.5 hours and maintained for 3 hours, the distillation of phenol stopped. Then, water was added dropwise at 145°C and 14 kPa to remove the residual phenol. Then, after the water was removed by maintaining at 155°C and 1 kPa for 1 hour, a composition (B'-1) different from the component (B) of the present invention was obtained as a residual liquid.

[0058] The GPC measurement results of the obtained composition (B'-1) showed that the content of component (B1) was 32.7 area % (less than 40 area %), the content of component (B2) was 23.3 area %, the content of component (B3) was 14.9 area %, and the content of component (B4) was 29.1 area %.

[0059] The composition of component (B1) determined by HPLC was 14.2 area % for compound (1), 14.5 area % for compound (2), and 3.2 area % for compound (3).

[0060] <Production Example 2> A composition (B'-2) different from the component (B) was obtained by reacting in the same manner as in Production Example 1 except that 303.2 g (3.22 mol) of phenol, 2.43 g of 10% oxalic acid aqueous solution and 183.8 g (2.14 mol) of 35% formaldehyde aqueous solution were used and distilling was performed.

[0061] The GPC measurement results of the obtained composition (B'-2) showed that the content of component (B1) was 13.3 area % (less than 40 area %), the content of component (B2) was 12.2 area %, the content of component (B3) was 9.9 area %, and the content of component (B4) was 64.6 area %.

[0062] The composition of component (B1) determined by HPLC was 7.4 area % for compound (1), 5.7 area % for compound (2), and 1.1 area % for compound (3).

[0063] <Production Example 3> In a four-necked flask equipped with a condenser, a stirrer, and a thermometer, 3228.0 g of phenol, 388.8 g of water, and 21.4 g of a 10% oxalic acid aqueous solution were placed, and after the temperature was raised to 70°C, 653.4 g of a 35% formaldehyde aqueous solution was added within 5 minutes. After the addition was completed, the temperature was raised to 90°C and stirring was continued for 6.0 hours. After the reaction was completed, distillation was started under the conditions of 80°C and 47kPa. After 11.5 hours of heating to an internal temperature of 145°C (3kPa) and maintaining for 3 hours, the distillation of phenol stopped. Then, water was added dropwise at 145°C and 14kPa to remove the residual phenol. Then, after maintaining at 155°C and 1kPa for 1 hour to remove the water, a composition (B-1) of component (B) was obtained as a residual liquid.

[0064] The GPC measurement results of the obtained composition (B-1) showed that the content of the component (B1) was 56.7 area %, the content of the component (B2) was 25.0 area %, the content of the component (B3) was 10.5 area %, and the content of the component (B4) was 7.8 area %.

[0065] The composition of component (B1) determined by HPLC was 20.9 area % for compound (1), 26.6 area % for compound (2), and 6.7 area % for compound (3).

[0066] The polystyrene-equivalent molecular weights obtained by GPC measurement were 313 for the component (B1), 457 for the component (B2), and 593 for the component (B3).

[0067] <Production Example 4> A composition (B'-3) different from component (B) was obtained by reacting in the same manner as in Production Example 3 except that 4051 parts by weight of phenol, 142.7 parts by weight of water, 17.4 parts by weight of a 10% aqueous oxalic acid solution and 125 g of a 35% aqueous formaldehyde solution were used and distilling was performed.

[0068] The GPC measurement results of the obtained composition (B'-3) showed that the binuclear content of component (B1) was 90.6 area % (exceeding 70 area %), the content of component (B2) was 9.4 area %, and components (B3) and (B4) were not detected.

[0069] The composition of component (B1) determined by HPLC was 31.2 area % for compound (1), 43.9 area % for compound (2), and 15.2 area % for compound (3).

[0070] <Production Example 5> In a four-necked flask equipped with a condenser, a stirrer, and a thermometer, 493.7 g (5.24 mol) of phenol and 2.89 g of a 10% oxalic acid aqueous solution were placed, and after the temperature was raised to 70°C, 84.4 g (0.99 mol) of a 35% formaldehyde aqueous solution was added within 5 minutes. After the addition was completed, the temperature was raised to 90°C and stirring was continued for 6 hours. After the reaction was completed, distillation was started under the conditions of 80°C and 47 kPa. After 3.5 hours of heating to an internal temperature of 145°C (3 kPa) and maintaining for 3 hours, the distillation of phenol stopped. Then, water was added dropwise at 145°C and 14 kPa to remove residual phenol. Then, after maintaining at 155°C and 1 kPa for 1 hour to remove the water, a composition (B-2) of component (B) was obtained as a residual liquid.

[0071] The GPC measurement results of the obtained composition (B-2) showed that the content of the component (B1) was 62.0 area %, the content of the component (B2) was 24.5 area %, the content of the component (B3) was 8.4 area %, and the content of the component (B4) was 5.1 area %.

[0072] The composition of component (B1) determined by HPLC was 22.1% by area of ​​compound (1), 30.6% by area of ​​compound (2), and 8.5% by area of ​​compound (3).

[0073] The polystyrene-equivalent molecular weights obtained by GPC measurement were 324 for the component (B1), 474 for the component (B2), and 611 for the component (B3).

[0074] <Production Example 6> To 1.00 g of the mixture obtained in Preparation Example 1 was added 1.25 g of the composition (B'-3) obtained in Preparation Example 4, and the mixture was heated stepwise to 130 to 180° C. to melt, and then cooled to obtain a composition (B'-4) different from the component (B).

[0075] The GPC measurement results of the obtained composition (B'-4) showed that the content of the component (B1) was 75.3 area %, the content of the component (B2) was 15.5%, the content of the component (B3) was 5.5%, and the content of the component (B4) was 3.7%.

[0076] <Example 1> 0.9 g of a commercially available resol type phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd.) was added to a 10 mL sample tube, and 0.1 g of a composition (B-1) of component (B) obtained in Production Example 3 having a component (B1) content of 56.7 area % was added thereto. The sample tube was placed in an oil bath and heated and mixed at 90° C. for 10 minutes while stirring. The mixed composition was cooled to room temperature and then heated at 170° C. for 10 minutes to obtain a cured product.

[0077] The Td5% of the obtained cured product was measured.

[0078] The commercially available resol-type phenolic resin used was confirmed by GPC measurement to have a number average molecular weight (Mn) of 960 and a weight average molecular weight (Mw) of 16,000.

[0079] <Example 2> A cured product was obtained by heating in the same manner as in Example 1 except that the curing was performed at 180°C.

[0080] The Td5% of the obtained cured product was measured.

[0081] <Example 3> Heating was performed in the same manner as in Example 2, except that 0.1 g of the composition (B-2) containing 62.0 area % of the component (B) obtained in Production Example 5 was added instead of 0.1 g of the composition (B-1) containing 56.7 area % of the component (B) was added. A cured product was obtained.

[0082] The Td5% of the obtained cured product was measured.

[0083] <Example 4> A cured product was obtained by heating in the same manner as in Example 1 except that the curing was performed at 200°C.

[0084] The Td5% of the obtained cured product was measured.

[0085] <Comparative Examples 1 to 3> A cured product was obtained by heating in the same manner as in Example 1 except that 1.0 g of the same commercially available resol type phenolic resin as in Example 1 was used and no component (B) was added to the composition and the composition was cured at 170° C. (Comparative Example 1), 180° C. (Comparative Example 2), and 200° C. (Comparative Example 3).

[0086] Td5% of each of the obtained cured products was measured.

[0087] <Comparative Example 4> Heating was performed in the same manner as in Example 1, except that 0.1 g of the composition (B'-1) containing 32.7% of the component (B1) obtained in Production Example 1 was added instead of 0.1 g of the composition (B-1) containing 56.7% of the component (B). A cured product was obtained.

[0088] The Td5% of the obtained cured product was measured.

[0089] <Comparative Example 5> Heating was performed in the same manner as in Example 1, except that 0.1 g of the composition (B'-2) obtained in Production Example 2 having a content of 13.3% of the component (B1) was added instead of 0.1 g of the composition (B-1) having a content of 56.7% of the component (B) was added, to obtain a cured product.

[0090] The Td5% of the obtained cured product was measured.

[0091] <Comparative Example 6> Heating was performed in the same manner as in Example 1, except that 0.1 g of the composition (B'-4) obtained in Production Example 6 having a content of 75.3% of the component (B1) was added instead of 0.1 g of the composition (B-1) having a content of 56.7% of the component (B) was added, to obtain a cured product.

[0092] The Td5% of the obtained cured product was measured.

[0093] <Comparative Example 7> A cured product was obtained by heating in the same manner as in Example 1 except that 0.1 g of the composition (B'-4) containing 75.3% of the component (B1) obtained in Production Example 6 was added instead of 0.1 g of the composition (B-1) containing 56.7% of the component (B) and the curing temperature was set to 180°C.

[0094] The Td5% of the obtained cured product was measured.

[0095] <Comparative Example 8> In the same manner as in the example, 0.9 g of a commercially available resol type phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd.) was added to a 10 mL sample tube, and 0.1 g of a composition (B'-3) containing 90.6 area % of component (B1) obtained in Production Example 4 was added thereto. The sample tube was placed in an oil bath and heated and mixed at 90° C. for 10 minutes while stirring. When the mixed composition was cooled to room temperature, crystals precipitated.

[0096] If the amount of the component (B1) in the component (B) of the present invention is too large, the compatibility with the resol type phenol resin decreases, and the storage stability also decreases.

[0097] On the other hand, in Examples 1 to 3 using the component (B) of the present invention in which the content of the component (B1) is 40 area % or more and 70 area % or less, the resol type phenolic resin of the component (A) and the component (B) have good compatibility, can maintain a uniform mixing state even after cooling, and have good storage stability.

[0098] <Comparative Example 9> The composition after mixing was not cooled but heated at 170°C for 10 minutes to obtain a cured product. A composition was prepared in the same manner as in Comparative Example 8. Td5% of the cured product obtained was measured to be 366°C.

[0099] The cured products of Examples 1 to 4 and Comparative Examples 1 to 7 are summarized in Table 1 below, including the content (area %) of the component (B1), the curing temperature, and Td5%.

[0100] [Table 1]

[0101] From the results of Example 1 and Comparative Examples 1, 4 to 6, and 9, Examples 2 and 3 and Comparative Examples 2 and 7, and Example 4 and Comparative Example 3 in Table 1, it was confirmed that when the curable composition of the present invention (Examples 1 to 4) containing a specific amount of component (B1) was cured under the same temperature conditions, the 5% weight loss temperature (Td) of the obtained cured product was high, and it was found that the heat resistance was greatly improved.

[0102] As shown in Table 1, it can be seen that the curable composition of the present invention can be cured at a lower temperature than the conventionally known resol type phenolic resin. Therefore, the curable composition of the present invention can reduce the temperature of the curable resin during the molding process, and can improve efficiency by shortening the heating and cooling time or saving energy. In addition, it can also be used for heat-sensitive materials (substrates), which is very useful.

[0103] <Example 5> 0.9 g of a commercially available resol-type phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd.) and 0.1 g of a composition (B-1) of component (B) having a content of component (B1) of 56.7 area % obtained in Production Example 3 were mixed and cooled in the same manner as in Example 1. The obtained mixture was measured using a differential scanning calorimeter under the above-mentioned measurement conditions.

[0104] <Comparative Example 10> The measurement was performed on a commercially available resol-type phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd.) using a differential scanning calorimeter under the above-mentioned measurement conditions.

[0105] The differential scanning calorimetry (DSC) curves of Example 5 and Comparative Example 10 are shown in FIG. 1 , with Example 5 being a solid line and Comparative Example 10 being a dotted line. Figure 1 .exist Figure 1 In the solid horizontal arrow and the dotted horizontal arrow in FIG. , the left end indicates the curing start temperature, and the right end indicates the curing end temperature.

[0106] like Figure 1 As shown by the solid horizontal arrows and the dotted horizontal arrows in the figure, the curable composition of the present invention (Example 5) containing a specific amount of component (B1) has a lower curing end temperature than the conventionally known resol type phenolic resin (Comparative Example 10) when the temperature is raised under the same measurement conditions, even if the curing start temperature is the same, and it can be seen that the curing is completed in a shorter time.

[0107] Differential scanning calorimetry (DSC) showed that the calorific value (ΔH) of Example 5 was 192 J / g and the peak top temperature was 200°C, while the calorific value (ΔH) of Comparative Example 10 was 216 J / g and the peak top temperature was 202°C.

[0108] It is also clear from the results that the curable composition of the present invention can be cured in a short time with less heat generation than the conventionally known resol type phenolic resin. It is thus known that the curable composition of the present invention can be very useful because it can bring about efficiency improvement by shortening the heating and cooling time or saving energy.

Claims

1. A curable composition, characterized in that Contains the following ingredient (A) and the following ingredient (B), Component (A): resol type phenolic resin; Ingredients (B): A composition comprising a component (B1) consisting of the following compound (1), compound (2) and compound (3), wherein the total amount of the component (B1) is in the range of 40 area % to 70 area % relative to the total amount of all components detected by gel permeation chromatography using a differential refractometer as a detector, [Chemistry 1] 。 2. A solidified product, characterized in that: The curable composition according to claim 1 is cured.

3. A resol type phenolic resin curing agent, characterized in that: Contains the following ingredients (B), Ingredients (B): A composition comprising a component (B1) consisting of the following compound (1), compound (2) and compound (3), wherein the total amount of the component (B1) is in the range of 40 area % to 70 area % relative to the total amount of all components detected by gel permeation chromatography using a differential refractometer as a detector, [Chemistry 2] 。 4. A binder, characterized in that: A curable composition comprising the curable composition according to claim 1.

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