Polyamide polymer

Abstract

To provide a polyamide-based polymer which has high mechanical strength and toughness and excellent peelability after adhesion capable of easily being removed from a substrate after coating and to provide an adhesive and a molding material in which a polyhydric phenol compound useful as a production intermediate of the polyamide-based polymer and the polyamide-based polymer are used.SOLUTION: There is provided a polyamide-based polymer having a repeating unit represented by formula (II) (wherein, R3 represents a bivalent organic group).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyamide-based polymer. More specifically, the present invention relates to a polyamide-based polymer and a polyhydric phenol compound useful as a raw material for the polyamide-based polymer. The polyamide-based polymer of the present invention is expected to be used, for example, in adhesives, molding materials, etc. [Background technology]

[0002] Cinnamic acids contained in wood lignin have carbon-carbon unsaturated double bonds and carboxyl groups in their molecules and exhibit the property of dimerizing when irradiated with ultraviolet light, and are therefore used as raw materials for functional materials (see, for example, Non-Patent Documents 1 to 3).

[0003] Caffeic acid is known as a compound similar to cinnamic acid. Materials using caffeic acid as a raw material are known to have properties such as antioxidant activity, metal coordination function, and adhesiveness (see, for example, Non-Patent Documents 4 and 5).

[0004] Furthermore, polyesters using caffeic acid as a raw material have been reported to have excellent adhesive properties (see, for example, Patent Document 1 and Non-Patent Document 6).

[0005] However, although the polyester has excellent adhesive properties, it has the drawback of low mechanical strength and toughness due to weak intermolecular entanglement. Furthermore, since it is difficult to peel the polyester from a substrate after coating the substrate, the polyester is required to have a property that allows it to be easily removed after being attached to the substrate. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2012 / 102174 Brochure [Non-patent literature]

[0007] [Non-Patent Document 1] Kaneko, T. et al., Nature Mater. 2006, 5, 966-970 [Non-patent document 2] Macromolecules 2008, 41, 8167-8172 [Non-patent document 3] Angew. Chem. Int. Ed. 2013, 52, 11143-11148 [Non-patent document 4] Messersmith, PB al., Science 2007, 318, 426-430 [Non-Patent Document 5] Kaneko, T. et al., Pure Appl. Chem.. 2012, 84, 2559-2568 [Non-patent document 6] Kaneko, T. et al., Plant Biotechnology, 2010, 27, 293-296 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in view of the above-mentioned conventional techniques, and an object of the present invention is to provide a polyamide-based polymer that has high mechanical strength and toughness and that can be easily removed from a substrate after application and thus is easily peelable after adhesion; a polyhydric phenol compound that is useful as a production intermediate for the polyamide-based polymer; and an adhesive and molding material that use the polyamide-based polymer. [Means for solving the problem]

[0009] The present invention provides (1) Formula (I):

[0010] [ka]

[0011] (In the formula, R 1 and R 2 each independently represents a hydrogen atom or a monovalent organic group. a polyhydric phenol compound represented by (2) Formula (II):

[0012] [ka]

[0013] (In the formula, R 3 represents a divalent organic group) A polyamide-based polymer having a repeating unit represented by (3) Formula (I):

[0014] [ka]

[0015] (In the formula, R 1 and R 2 each independently represents a hydrogen atom or a monovalent organic group. and a polyhydric phenol compound represented by formula (III): H2N-R 3 -NH2(III) (In the formula, R 3 represents a divalent organic group) and a diamine compound represented by formula (II):

[0016] [ka]

[0017] (In the formula, R 3 is the same as above) A method for producing a polyamide polymer having a repeating unit represented by (4) An adhesive containing the polyamide polymer described in (2) above, and (5) A molding material containing the polyamide polymer described in (2) above. Regarding. [Effects of the Invention]

[0018] According to the present invention, there are provided a polyamide-based polymer that has high mechanical strength and toughness and that can be easily removed from a substrate after application, a polyhydric phenol compound that is useful as a production intermediate for the polyamide-based polymer, and an adhesive and a molding material that use the polyamide-based polymer. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a graph showing the nuclear magnetic resonance ( 1 H-NMR) spectrum of polyphenol compound A obtained in Example 2. [Figure 2] 1 is a graph showing the nuclear magnetic resonance ( 1 H-NMR) spectrum of polyphenol compound B obtained in Example 3. [Figure 3] 1 is a graph showing the nuclear magnetic resonance ( 1 H-NMR) spectrum of polyamide A obtained in Example 4. [Figure 4] 1 is a graph showing the FT-IR spectrum of polyamide A obtained in Example 4. [Figure 5] 1 is a graph showing the nuclear magnetic resonance ( 1 H-NMR) spectrum of polyamide B obtained in Example 5. [Figure 6] 1 is a graph showing the FT-IR spectrum of Polyamide B obtained in Example 5. [Figure 7] 1 is a graph showing the nuclear magnetic resonance ( 1 H-NMR) spectrum of polyamide C obtained in Example 6. [Figure 8] 1 is a graph showing the FT-IR spectrum of Polyamide C obtained in Example 6. [Figure 9] 1 is a graph showing the nuclear magnetic resonance ( 1 H-NMR) spectrum of polyamide D obtained in Example 7. [Figure 10] 1 is a graph showing the FT-IR spectrum of Polyamide D obtained in Example 7. [Figure 11] 1 is a graph showing the FT-IR spectrum of Polyamide E obtained in Example 8. [Figure 12] 1 is a graph showing the FT-IR spectrum of Polyamide F obtained in Example 9. [Figure 13] 1 is a graph showing the nuclear magnetic resonance ( 1 H-NMR) spectrum of polyamide G obtained in Example 10. [Figure 14] 1 is a graph showing the FT-IR spectrum of polyamide G obtained in Example 10. [Figure 15] 1 is a graph showing the results of a tensile test using polyamide G obtained in Example 10. [Figure 16] 1 is a graph showing the results of examining adhesiveness using polyamide G obtained in Example 10. DETAILED DESCRIPTION OF THE INVENTION

[0020] (1) Polyphenol compounds As described above, the polyhydric phenol compound of the present invention is represented by the formula (I):

[0021] [ka]

[0022] (In the formula, R 1 and R 2 each independently represents a hydrogen atom or a monovalent organic group. The polyhydric phenol compound of the present invention is useful as a raw material for the polyamide polymer of the present invention.

[0023] In formula (I), R 1 and R 2are each independently a hydrogen atom or a monovalent organic group. Examples of monovalent organic groups include monovalent aliphatic hydrocarbon groups which may have a substituent, monovalent aromatic hydrocarbon groups which may have a substituent, and monovalent hydrocarbon groups having an alicyclic structure which may have a substituent. The monovalent aliphatic hydrocarbon groups, monovalent aromatic hydrocarbon groups, and monovalent hydrocarbon groups having an alicyclic structure may all have a substituent within the scope of the present invention. Examples of the substituent include an amino group, a hydroxyl group, and a halogen atom, but the present invention is not limited to these examples.

[0024] Examples of monovalent aliphatic hydrocarbon groups include alkyl groups having 1 to 12 carbon atoms, but the present invention is not limited to these examples. Examples of monovalent aromatic hydrocarbon groups include aryl groups having 6 to 12 carbon atoms, but the present invention is not limited to these examples. Examples of monovalent hydrocarbon groups having an alicyclic structure include cycloalkyl groups having 3 to 6 carbon atoms, but the present invention is not limited to these examples. R 1 and R 2 From the viewpoint of increasing the reactivity with the diamine described below, each of the groups is preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0025] The polyphenol compound of the present invention can be prepared using caffeic acid as a starting material. Since caffeic acid is an aromatic carboxylic acid contained in coffee, it may be extracted from coffee or synthesized using petroleum as a raw material. Among these, caffeic acid extracted from coffee has the advantage of being more environmentally friendly than caffeic acid synthesized using petroleum as a raw material. Caffeic acid is readily available commercially, for example, from Tokyo Chemical Industry Co., Ltd.

[0026] In addition to caffeic acid, caffeic acid derivatives can also be used as raw materials for the polyhydric phenol compound of the present invention. When the caffeic acid derivative is a caffeic acid ester, the caffeic acid ester can be easily prepared, for example, by using caffeic acid as a starting material, reacting caffeic acid with an alcohol, and removing the resulting water as necessary. The alcohol may be either an aliphatic alcohol or an aromatic alcohol, and may have a substituent such as an amino group or a halogen atom, as long as the object of the present invention is not impaired. Among alcohols, monohydric aliphatic alcohols having 1 to 8 carbon atoms are preferred, and monohydric aliphatic alcohols having 1 to 4 carbon atoms are more preferred.

[0027] In formula (I), R 1 and R 2 The polyhydric phenol compound in which R are each independently a monovalent organic group can be easily prepared, for example, by preparing a caffeic acid derivative by the above-mentioned method and irradiating the caffeic acid derivative with ultraviolet light. 1 and R 2 are each independently a hydrogen atom, the polyhydric phenol compound is, for example, 1 and R 2 It can be easily prepared by reducing a polyhydric phenol compound in which each R is independently a monovalent organic group with a reducing agent such as sodium hydroxide. 1 and R 2 As described above, from the viewpoint of increasing the reactivity with diamine, each of the groups is preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0028] The polyhydric phenol compound represented by formula (I) obtained in the above manner is useful as a raw material for the polyamide polymer of the present invention.

[0029] (2) Polyamide polymers As described above, the polyamide-based polymer of the present invention is a polymer represented by the formula (II):

[0030] [ka]

[0031] (In the formula, R 3 represents a divalent organic group) The repeating unit has the following structure:

[0032] In formula (II), R 3 The divalent organic group is a group derived from a diamine compound used as a raw material in preparing the polyamide polymer of the present invention, and will be described in detail below.

[0033] The polyamide polymer represented by formula (II) is prepared by reacting a polyhydric phenol compound represented by formula (I) with a compound represented by formula (III): H2N-R 3 -NH2(III) (In the formula, R 3 represents a divalent organic group) The compound can be easily prepared by reacting a diamine compound represented by the formula:

[0034] In the diamine compound represented by formula (III), R 3 is a divalent organic group. Examples of the divalent organic group include a divalent aliphatic group and a divalent aromatic group. A divalent aromatic group refers to a divalent group having an aromatic ring. R 3 is a divalent aliphatic group, the diamine compound represented by formula (III) is an aliphatic diamine, and R 3 When is a divalent aromatic group, the diamine compound represented by formula (III) is an aromatic diamine. The aliphatic diamine and the aromatic diamine may be used alone or in combination.

[0035] Examples of divalent aliphatic groups include alkylene groups having 2 to 12 carbon atoms which may have a branched chain. Examples of divalent aromatic groups include arylene groups having 6 to 12 carbon atoms. Among divalent aliphatic groups and divalent aromatic groups, divalent aliphatic groups are preferred, and alkylene groups having 3 to 12 carbon atoms which may have a branched chain are more preferred, from the viewpoint of obtaining a polyamide-based polymer having high mechanical strength and toughness and properties that allow it to be easily removed from a substrate after coating.

[0036] In formula (III), R 3 As the diamine compound in which is a divalent aliphatic group, there is a compound represented by the formula (IIIa): H2N-R 4 -NH2(IIIa) (In the formula, R 4 represents a divalent aliphatic group which may contain an oxygen atom) Examples of the aliphatic diamine compounds include those represented by R 4 is a divalent aliphatic group which may have an oxygen atom, and examples thereof include, as above, an alkylene group having 2 to 12 carbon atoms which may have an oxygen atom or a branched chain.

[0037] Specific examples of the aliphatic diamine compound include aliphatic diamine compounds having a straight chain and 2 to 12 carbon atoms, such as ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, and dodecamethylenediamine; 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 3-ethyl-1,5-pentanediamine, and 2-methyl-1,6-hexanediamine; hexanediamine, 2-ethyl-1,6-hexanediamine, 3-methyl-1,6-hexanediamine, 3-ethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, 3-methyl-1,8-octanediamine, 4-methyl-1,8-octanediamine, 2-ethyl-1,8-octanediamine, 3-ethyl-1,8-octanediamine, 4-ethyl-1,8-octanediamine, 3-propyl-1,8-octanediamine, 2-butyl-1,8-octanediamine, 3-butyl-1,8-octanediamine, 4-butyl ethyl-1,8-octanediamine, 2-methyl-1,9-nonanediamine, 3-methyl-1,9-nonanediamine, 4-methyl-1,9-nonanediamine, 2-ethyl-1,9-nonanediamine, 3-ethyl-1,9-nonanediamine, 4-ethyl-1,9-nonanediamine, 2-propyl-1,9-nonanediamine, 3-propyl-1,9-nonanediamine, 4-propyl-1,9-nonanediamine, 2-methyl-1,10-decanediamine, 3-methyl-1,10-decanediamine, 4-methyl-1,10-decanediamine Examples of the diamine compounds include aliphatic diamine compounds having 3 to 12 carbon atoms and branched chains, such as 2-ethyl-1,10-decanediamine, 3-ethyl-1,10-decanediamine, and 4-ethyl-1,10-decanediamine, and ether-based diamine compounds having 3 to 12 carbon atoms, such as triethanoldiamine, ethylene glycol diamine, diethylene glycol diamine, triethylene glycol diamine, propylene glycol diamine, and polypropylene glycol diamine, but the present invention is not limited to these examples. These diamine compounds may be used alone or in combination of two or more.

[0038] In formula (III), R 3 As the diamine compound in which is a divalent aromatic group, there is a compound represented by the formula (IIIb): H2N-R 5 -NH2(IIIb) (In the formula, R 5 represents a group having a divalent aromatic group) Examples of the aromatic diamine compound include aromatic diamines having 6 to 12 carbon atoms, such as phenylenediamine, xylylenediamine, naphthylenediamine, and biphenylenediamine;

[0039] [ka]

[0040] (In the formula, R 6 and R 7 each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. and aminocinnamic acid dimers and esters thereof represented by the formula:

[0041] [ka]

[0042] However, the present invention is not limited to these examples. These aromatic diamine compounds may be used alone or in combination of two or more.

[0043] Theoretically, a polyhydric phenol compound having two carboxyl groups and a diamine compound having two amino groups react in stoichiometric amounts. Therefore, the amount of the diamine compound having two amino groups per mole of the polyhydric phenol compound having two carboxyl groups is theoretically 1 mole, but in the present invention, the amount of the diamine compound per mole of the polyhydric phenol compound is preferably about 0.90 to 1.10 moles, and more preferably about 0.95 to 1.05 moles.

[0044] In the present invention, a portion of the polyhydric phenol compound may be substituted with another compound (hereinafter simply referred to as another compound) within the scope that does not impair the object of the present invention. Examples of the other compound include a dicarboxylic acid compound. The dicarboxylic acid compound includes an aliphatic dicarboxylic acid and an aromatic dicarboxylic acid.

[0045] Examples of aliphatic dicarboxylic acids include aliphatic dicarboxylic acids having 2 to 20 carbon atoms, such as oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, and azelaic acid, but the present invention is not limited to these examples. These aliphatic dicarboxylic acids may be used alone or in combination of two or more.

[0046] Examples of aromatic dicarboxylic acids include orthophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenyletherdicarboxylic acid, etc., but the present invention is not limited to these examples. These aromatic dicarboxylic acids may be used alone or in combination of two or more.

[0047] The polyhydric phenol compound and the diamine compound can be reacted in an organic solvent. Examples of the organic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, trifluoroacetic acid, and dimethyl sulfoxide, but the present invention is not limited to these examples. These organic solvents may be used alone or in combination of two or more.

[0048] The amount of the organic solvent is not particularly limited as long as it is an amount that allows the polyhydric phenol compound and the diamine compound to react efficiently, but it is usually preferable that the amount be about 1 to 20 times the total amount (mass) of the polyhydric phenol compound and the diamine compound.

[0049] In addition, when reacting a polyhydric phenol compound with a diamine compound, from the viewpoint of efficiently preparing a polyamide-based polymer, it is preferable to add, as a condensing agent, triphenyl phosphite and pyridine to the reaction system of the polyhydric phenol compound and the diamine compound, or to add a complex consisting of triphenyl phosphite and pyridine to the reaction system of the polyhydric phenol compound and the diamine compound. The amount of the condensing agent per mole of the total amount of the polyhydric phenol compound and the diamine compound is usually preferably about 1 to 2 moles.

[0050] In addition, from the viewpoint of efficiently reacting the polyhydric phenol compound with the diamine compound, it is preferable to use an appropriate amount of catalyst. Examples of catalysts include lithium chloride, sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, lithium dihydrogen phosphate, dilithium hydrogen phosphate, and trilithium phosphate, but the present invention is not limited to these examples. Among the catalysts, lithium chloride is preferred.

[0051] The reaction temperature when reacting a polyphenol compound with a diamine compound is not particularly limited, but is preferably about 40 to 80°C from the viewpoint of increasing reaction efficiency. The reaction time when reacting a polyphenol compound with a diamine compound cannot be determined in general because it varies depending on the amount of organic solvent used, the reaction temperature, etc., but is usually about 10 to 30 hours. The atmosphere when reacting a polyphenol compound with a diamine compound is preferably an inert gas such as nitrogen gas or argon gas from the viewpoint of avoiding the influence of oxygen contained in the air.

[0052] After the reaction is completed, the polyamide polymer is crystallized from the resulting reaction mixture. Examples of methods for precipitating the polyamide polymer from the reaction mixture include adding the reaction mixture to a poor solvent such as an aliphatic alcohol having 1 to 3 carbon atoms, such as methanol, ethanol, or propanol, a ketone compound such as acetone or methyl ethyl ketone, or ethyl acetate, tetrahydrofuran, dioxane, chloroform, dichloromethane, chlorobenzene, phenol, or cresol, or gradually evaporating the solvent contained in the reaction mixture, but the present invention is not limited to these methods.

[0053] The precipitated polyamide-based polymer can be recovered by a method such as filtration, etc. The recovered polyamide-based polymer may be washed with a poor solvent having a temperature of about 0 to 25°C, if necessary.

[0054] The polyamide-based polymer obtained as described above may be purified, if necessary, by dissolving it in a solvent such as N,N-dimethylformamide and then precipitating it with a ketone compound such as acetone. The polyamide-based polymer obtained as described above may also be dried, for example, by drying under reduced pressure.

[0055] The number average molecular weight of the polyamide polymer obtained above is not particularly limited, but from the viewpoint of enhancing the decomposition property of the polyamide polymer by irradiation with far ultraviolet light and improving adhesiveness and heat resistance, it is preferably 12,000 to 200,000, and more preferably 15,000 to 100,000. The number average molecular weight of the polyamide polymer is a value measured according to the method described in the following examples.

[0056] The polyamide polymer of the present invention may contain an appropriate amount of additives depending on the intended use, as necessary. Examples of additives include colorants such as pigments and dyes, UV absorbers, UV stabilizers, antioxidants, rust inhibitors, antibacterial agents, plasticizers, algae inhibitors, mildew inhibitors, flame retardants, and foaming agents, but the present invention is not limited to these examples. These additives may be used alone or in combination of two or more. The amount of additive varies depending on the type of additive, so it cannot be determined in general. Therefore, it is preferable to determine the amount appropriately depending on the type of additive.

[0057] (3) Applications of polyamide polymers The polyamide-based polymer of the present invention has high mechanical strength and toughness, can be easily removed from a substrate after coating, and has excellent adhesion to various substrates. Therefore, the polyamide-based polymer of the present invention can be suitably used as an adhesive. When using the polyamide-based polymer of the present invention as an adhesive, the polyamide-based polymer of the present invention can be softened by heating to a temperature of about 80 to 100°C, sandwiched between two substrates, and then cooled to bond the substrates together. Furthermore, the polyamide-based polymer of the present invention has the property of swelling in organic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, trifluoroacetic acid, and dimethyl sulfoxide. Therefore, the substrates can be bonded together by sandwiching the polyamide-based polymer swollen in the organic solvent between two substrates and then volatilizing and removing the organic solvent.

[0058] Examples of the substrate include inorganic substrates such as stainless steel plates such as SUS304 and SUS430, glass plates, wood plates, ceramic plates, bricks, mortar plates, concrete plates, and paper, and resin substrates such as ABS resin, AS resin, and polycarbonate, but the present invention is not limited to these examples.

[0059] The polyamide-based polymer of the present invention has the property that when irradiated with light such as far ultraviolet light having a wavelength of about 10 to 220 nm, it decomposes to a lower molecular weight and its adhesiveness decreases. Therefore, when it becomes necessary to peel off an adhesive containing the polyamide-based polymer of the present invention after it has been applied to a substrate, the polyamide-based polymer can be decomposed and easily removed from the substrate by irradiating the adhesive layer with light such as far ultraviolet light.

[0060] Therefore, adhesives using the polyamide-based polymer of the present invention not only simplify the adhesive removal process, but also significantly reduce damage and deterioration of adherends such as glass substrates and paper, and further allow the decomposition products of the polyamide-based polymer to be reused.

[0061] Furthermore, a polyamide polymer solution obtained by dissolving the polyamide polymer of the present invention in an organic solvent can be suitably used as a film molding material, an injection molding material, or other molding material. [Example]

[0062] Next, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[0063] The physical properties of the polymers obtained in the following examples and comparative examples were examined according to the following methods.

[0064] [Polymer structure] The structure of the polymer was determined by nuclear magnetic resonance ( 1The carbon-carbon bond was determined by H-NMR and Fourier transform infrared spectroscopy (FT-IR).

[0065] Nuclear magnetic resonance ( 1 H-NMR was measured using a nuclear magnetic resonance spectrometer (manufactured by BRUKER, trade name: AVANCE III HD NMR Spectrometer 400 MHz) by dissolving 5 mg of sample (polymer) in 0.5 mL of dimethyl sulfoxide-d6, transferring the obtained solution to a glass sample tube, and measuring at a temperature of 25°C with 16 accumulations.

[0066] Fourier transform infrared spectroscopy (FT-IR) was performed using an infrared spectrometer (Perkin Elmer, product name: Spectrum 100, ATR method) in the measurement wavenumber range of 400 to 4000 cm -1 The measurement was carried out four times.

[0067] [Number average molecular weight of polymer] The number average molecular weight of the polymer was determined by gel permeation chromatography (GPC). More specifically, the equipment used was a liquid pump unit (manufactured by JASCO Corporation, product number: PU-2080), a column oven (manufactured by GL Sciences Inc., product number: CO631A, set temperature: 40°C), an ultraviolet-visible detector (manufactured by JASCO Corporation, product number: UV-2075), a differential refractometer (manufactured by JASCO Corporation, product number: RI-2031), two columns (manufactured by Showa Denko K.K., product name: Shodex SB-806M HQ), and a standard substance (polymethyl methacrylate standard, molecular weights: 3070, 7360, 18500, 68800, 211000, 569000, and 1050000). The mobile phase was an N,N-dimethylformamide solution containing 0.01 mol / L LiBr, and the flow rate of the solution was adjusted to 1.0 mL / min.

[0068] Example 1 [Preparation of caffeic acid methyl ester] [ka]

[0069] 40 g (0.22 mol) of caffeic acid and 1.2 mL of 98% concentrated sulfuric acid were dissolved in 500 mL of methanol, and the resulting solution was stirred at 70° C. for 17 hours.

[0070] Next, methanol was removed from the solution using an evaporator, and the residue was dissolved in ethyl acetate. The resulting solution was then separated with distilled water and saturated brine, the organic phase was recovered, and the ethyl acetate was removed from the organic layer using an evaporator, yielding 30.7 g of caffeic acid methyl ester as a brown solid (yield: 72%).

[0071] Example 2 [Preparation of polyphenol compound A] [ka]

[0072] 20 g (0.103 mol) of caffeic acid methyl ester prepared in the same manner as in Example 1 was added to 1000 mL of hexane and dispersed. The resulting dispersion was irradiated with ultraviolet light of wavelengths of 200 to 380 nm (intensity: 100 μW / cm 2 ) was irradiated for 24 hours.

[0073] Next, the dispersion liquid irradiated with ultraviolet light was filtered under suction to obtain 19 g of polyhydric phenol compound A as a white solid (yield: 95%).

[0074] The polyhydric phenol compound A obtained above 1 H-NMR spectrum and 13 The C-NMR spectrum is as shown below: 1 The H-NMR spectrum is shown in Figure 1.

[0075] [ 1 H-NMR spectrum] 1H-NMR(400MHz, DMSO-d6) δ3.30(s, 6H, CH), 3.70(dd, 2H, CH), 4.08(dd, 2H, CH), 6.53(dd, 2H, ArH), 6.64(s, 2H, ArH), 6.66(d, 2H, ArH), 8.80(brs, 4H, OH)

[0076] [ 13 C-NMR spectrum] 13 C-NMR(400MHz, DMSO-d6) 40.5, 46.4, 51.2, 114.8, 115.3, 118.1, 129.6, 144.1, 144.9, 172.0

[0077] Example 3 [Preparation of polyphenol compound B] [ka]

[0078] 19 g (0.049 mol) of polyphenol compound A prepared in the same manner as in Example 2 was dissolved in 73.5 mL of 2 mol / L aqueous sodium hydroxide solution, and the resulting solution was stirred at 60°C for 15 hours under a nitrogen gas atmosphere to obtain a reaction solution. Hydrochloric acid was added to the reaction solution obtained above to make the reaction solution acidic, and then the organic layer was extracted with ethyl acetate. The extracted organic phase was washed with water, and the ethyl acetate contained in the organic layer was distilled off using an evaporator to obtain 9.36 g of polyphenol compound B as a pale yellow powder (yield: 53%).

[0079] The polyhydric phenol compound B obtained above 1 H-NMR spectrum and 13 The C-NMR spectrum is as shown below: 1 The H-NMR spectrum is shown in Figure 2.

[0080] [ 1 H-NMR spectrum] 1H-NMR(400MHz, DMSO-d6) δ3.56(dd, 2H, CH), 4.00,(dd, 2H, CH), 6.54(dd, 2H, ArH), 6.64(d, 2H, ArH), 6.67(d, 2H, ArH), 8.71-8.79(m, 4H, OH), 11.96(s, 2H, COOH)

[0081] [ 13 C-NMR spectrum] 13 C-NMR(400MHz, DMSO-d6) 40.6, 46.8, 115.1, 115.3, 118.4, 130.39, 144.1, 144.9, 173.1

[0082] Example 4 [Preparation of Polyamide A] [ka]

[0083] A flask whose air had been replaced with nitrogen gas was charged with 2 mL of N,N-dimethylacetamide, and then 382 mg (1.06 mmol) of polyhydric phenol compound B prepared in the same manner as in Example 3, 63.7 mg (1.06 mmol) of ethylenediamine, 0.71 mL (2.71 mmol) of triphenyl phosphite, 0.97 mL (12.0 mmol) of pyridine, and 90 mg of lithium chloride were added to the flask, and the contents of the flask were reacted at 60°C for 24 hours with stirring.

[0084] After the reaction was completed, the reaction mixture in the flask was added to methanol, and the resulting precipitate was filtered by suction to obtain 331.0 mg of polyamide A (yield: 81.2%). The number average molecular weight of the obtained polyamide A was 21,000. 1 The H-NMR spectrum is shown in FIG. 3, and the FT-IR spectrum is shown in FIG.

[0085] Example 5 [Preparation of Polyamide B] [ka]

[0086] A flask purged with nitrogen gas was charged with 1 mL of N-methyl-2-pyrrolidone, and then 360.3 mg (1.00 mmol) of polyphenol compound B prepared in the same manner as in Example 3, 116.2 mg (1.00 mmol) of hexamethylenediamine, 0.61 mL (2.20 mmol) of triphenyl phosphite, 0.89 mL (11.0 mmol) of pyridine, and 166 mg of lithium chloride were added to the flask, and the contents of the flask were reacted at 60°C for 24 hours with stirring.

[0087] After the reaction was completed, the reaction mixture in the flask was added to methanol, and the resulting precipitate was filtered by suction to obtain 398.0 mg of polyamide B (yield: 90.0%). The number average molecular weight of the obtained polyamide B was 31,000. 1 The H-NMR spectrum is shown in FIG. 5, and the FT-IR spectrum is shown in FIG.

[0088] Example 6 [Preparation of Polyamide C] [ka]

[0089] A flask whose air had been replaced with nitrogen gas was charged with 4 mL of N,N-dimethylacetamide, and then 719 mg (2.00 mmol) of polyhydric phenol compound B prepared in the same manner as in Example 3, 344 mg (2.00 mmol) of 1,10-diaminodecane, 1.41 mL (5.38 mmol) of triphenyl phosphite, 1.94 mL (24.0 mmol) of pyridine, and 188 mg of lithium chloride were added to the flask, and the contents of the flask were reacted at a temperature of 60°C for 24 hours with stirring.

[0090] After the reaction was completed, the reaction mixture in the flask was added to methanol, and the resulting precipitate was filtered by suction to obtain 795 mg of polyamide C (yield: 80.2%). The number average molecular weight of the obtained polyamide C was 18,000. 1 The H-NMR spectrum is shown in FIG. 7, and the FT-IR spectrum is shown in FIG.

[0091] Example 7 [Preparation of Polyamide D] [ka]

[0092] A flask purged with nitrogen gas was charged with 2 mL of N-methyl-2-pyrrolidone, and then the flask was charged with 360.3 mg (1.00 mmol) of polyhydric phenol compound B prepared in the same manner as in Example 3, and a compound of the formula:

[0093] [ka]

[0094] 354.4 mg (1.00 mmol) of 4-aminocinnamic acid dimer dimethyl ester represented by the formula (hereinafter simply referred to as 4-aminocinnamic acid dimer dimethyl ester), 0.61 mL (2.20 mmol) of triphenyl phosphite, 0.89 mL (11.0 mmol) of pyridine, and 166 mg of lithium chloride were added, and the contents of the flask were reacted at a temperature of 60°C for 24 hours with stirring.

[0095] After the reaction was completed, the reaction mixture in the flask was added to methanol, and the resulting precipitate was filtered by suction to obtain 672 mg of polyamide D (yield: 99.0%). The number average molecular weight of the obtained polyamide D was 20,000. 1 The H-NMR spectrum is shown in FIG. 9, and the FT-IR spectrum is shown in FIG.

[0096] Example 8 [Preparation of Polyamide E] [ka]

[0097] A flask whose air had been replaced with nitrogen gas was charged with 3.0 mL of N,N-dimethylacetamide, and then 270.2 mg (0.75 mmol) of polyphenol compound B prepared in the same manner as in Example 3, 354.4 mg (1.00 mmol) of 4-aminocinnamic acid dimer dimethyl ester, 36.5 mg (0.25 mmol) of adipic acid, 0.49 mL (6.06 mmol) of triphenyl phosphite, 0.49 mL (6.06 mmol) of pyridine, and 151 mg of lithium chloride were added to the flask, and the contents of the flask were reacted at 60°C for 24 hours with stirring.

[0098] After the reaction was completed, the reaction mixture in the flask was added to methanol, and the resulting precipitate was filtered by suction to obtain 600 mg of polyamide E (yield: 96.0%). The number-average molecular weight of the obtained polyamide E was 30,000. The FT-IR spectrum of the obtained polyamide E is shown in Figure 11.

[0099] Example 9 [Preparation of Polyamide F] [ka]

[0100] A flask whose air had been replaced with nitrogen gas was charged with 3.0 mL of N,N-dimethylacetamide, and then 180.2 mg (0.50 mmol) of polyphenol compound B prepared in the same manner as in Example 3, 354.4 mg (1.00 mmol) of 4-aminocinnamic acid dimer dimethyl ester, 731 mg (0.50 mmol) of adipic acid, 0.49 mL (6.06 mmol) of triphenyl phosphite, 0.49 mL (6.06 mmol) of pyridine, and 151 mg of lithium chloride were added to the flask, and the contents of the flask were reacted at 60°C for 24 hours with stirring.

[0101] After the reaction was completed, the reaction mixture in the flask was added to methanol, and the resulting precipitate was filtered by suction to obtain 550 mg of polyamide F (yield: 96.2%). The number-average molecular weight of the obtained polyamide F was 29,000. The FT-IR spectrum of the obtained polyamide F is shown in Figure 12.

[0102] Example 10 [Preparation of Polyamide G] [ka]

[0103] A flask whose air had been replaced with nitrogen gas was charged with 5.0 mL of N,N-dimethylacetamide, and then 45.0 mg (0.125 mmol) of polyphenol compound B prepared in the same manner as in Example 3, 177.2 mg (0.50 mmol) of 4-aminocinnamic acid dimer dimethyl ester, 54.8 mg (0.375 mmol) of adipic acid, 0.35 mL (1.34 mmol) of triphenyl phosphite, 0.49 mL (6.06 mmol) of pyridine, and 151 mg of lithium chloride were added to the flask, and the contents of the flask were reacted at 60°C for 24 hours with stirring.

[0104] After the reaction was completed, the reaction mixture in the flask was added to methanol, and the resulting precipitate was filtered by suction to obtain 219 mg of polyamide G (yield: 84.5%). The number average molecular weight of the obtained polyamide G was 27,000. 1 The H-NMR spectrum is shown in FIG. 13, and the FT-IR spectrum is shown in FIG.

[0105] Next, as the physical properties of each polymer obtained above, the 5% weight loss temperature (T d5 ), 10% weight loss temperature (T d10 The glass transition temperature, tensile strength, elongation at break (elongation rate (%) relative to the original length), Young's modulus and toughness were investigated according to the following methods. The results are shown in Table 1.

[0106] [The 5% weight loss temperature of the polymer (T d5), 10% weight loss temperature (T d10 ) and glass transition temperature] The 5% weight loss temperature (T d5 ) and 10% weight loss temperature (T d10 ) was investigated by thermogravimetric analysis (TGA). Thermogravimetric analysis (TGA) was performed using a simultaneous differential thermal and thermogravimetric analyzer (Hitachi High-Tech Science Corporation, model number: STA7200) and a platinum pan, with a sample (polymer) weight of 4 to 8 mg, under a nitrogen gas atmosphere (nitrogen gas flow rate: 250 mL / min) and a reference blank (no sample). The measurement temperature was 25 to 800°C, and the heating rate was 10°C / min. The temperatures at which the sample weight decreased by 5% (5% weight loss temperature) and 10% (10% weight loss temperature) were defined as T d5 and T d10 It was decided.

[0107] The glass transition temperatures of polymers were determined by differential scanning calorimetry (DSC). Differential scanning calorimetry (DSC) was performed using a differential scanning calorimeter (Hitachi High-Tech Science Corporation, Model No. X-DSC7000T) and an aluminum pan. Samples (polymers) were measured in a 3-5 mg volume under a nitrogen gas atmosphere (nitrogen gas flow rate: 40 mL / min) using a reference blank (no sample). The measurement temperature was started at 25°C and increased at a rate of 10°C / min. The sample was heated to 200-300°C depending on the sample's decomposition temperature. The sample was then held at the maximum temperature for 5 minutes. The sample was then cooled from the maximum temperature to 25°C at a rate of 10°C / min and held at 25°C for 10 minutes. This cycle was repeated three times, and the data obtained from the second or third cycle was used. The glass transition temperatures of polymers were determined based on the results of the differential scanning calorimetry.

[0108] [Tensile strength, elongation at break and Young's modulus] 100 mg of each polymer was dissolved in N,N-dimethylacetamide (1 mL) and wet-spun onto a glass substrate to produce a 50 mm long, 50 μm thick fiber specimen. A rectangular section at one end of the specimen, measuring 5 mm long and 5 mm wide, was used as the tensile section, and it was attached to the chuck of a tensile testing machine (INSTRON Universal Testing Machine, Part Number: 3365-L5) to measure the tensile strength, elongation at break (% elongation relative to the original length), and Young's modulus. The tensile strength measurement results for polyamide G, an example of a polymer, are shown in Figure 15.

[0109] [Table 1]

[0110] The results shown in Table 1 indicate that the polyamides obtained in each Example all have good heat resistance, as their 10% weight loss temperatures are 300° C. or higher. Furthermore, the polyamides obtained in each Example all have high tensile strength (mechanical strength), low elongation at break, high Young's modulus, and excellent toughness, but it was difficult to measure these physical properties for polyamides other than Polyamide G.

[0111] Next, the adhesiveness of polyamide G was evaluated based on the following adhesiveness evaluation method. The results are shown in Figure 16. Figure 16 is a graph showing the results of examining adhesiveness using polyamide G. The results shown in Figure 16 indicate that the polyamide has an adhesive strength of 5 MPa or more, which is comparable to that of commercially available instant adhesives. It was also confirmed that polyamides A to F also have excellent adhesive strength, similar to polyamide G.

[0112] [Method for evaluating adhesiveness] Two rectangular stainless steel plates (SUS304) measuring 100 mm in length and 25 mm in width were prepared, and the short sides of the stainless steel plates were shifted by 5 mm to provide a clamping margin for the chuck. Polyamide was sandwiched between the stainless steel plates, and the stainless steel plates were pressed in a hot press at a temperature of 200°C and a pressure of 5 MPa for 5 minutes, and then cooled to room temperature to prepare test specimens.

[0113] The test piece obtained above was clamped at both short sides in a chuck and pulled at room temperature at a crosshead speed of 1 mm / sec using a tensile testing machine (Instron, product number: 3365-L5), to measure the maximum stress when the stainless steel plate slipped. [Industrial Applicability]

[0114] The polyamide polymer of the present invention can be easily prepared without requiring the complicated synthesis steps seen in functional polymers.

[0115] Furthermore, conventionally, when peeling an adhesive from a substrate, complicated and time-consuming physical removal methods have been used, such as softening the adhesive by heating and then wiping off the adhesive, dissolving or swelling the adhesive with a solvent and then wiping off the adhesive, or scraping off the adhesive with a spatula or the like.

[0116] In contrast, adhesives using the polyamide-based polymer of the present invention can be easily removed without the need for the physical removal methods described above, because the polyamide-based polymer is decomposed by irradiation with light (far ultraviolet rays).

[0117] Therefore, by using the polyamide-based polymer of the present invention as an adhesive, not only can the adhesive removal process be simplified but damage and deterioration of adherends such as glass substrates and paper can be significantly reduced. Furthermore, since the decomposition products of the polyamide-based polymer can be reused, the polyamide-based polymer of the present invention is expected to contribute to a sustainable society.

Claims

1. As a raw material, the formula (I): 【Chemistry 1】 (In the formula, R 1 and R 2 each independently represents a hydrogen atom or a monovalent organic group, and the monovalent organic group is a monovalent aliphatic hydrocarbon group which may have a substituent, a monovalent aromatic hydrocarbon group which may have a substituent, or a monovalent hydrocarbon group having an alicyclic structure which may have a substituent. The polyamide-based polymer uses a polyhydric phenol compound represented by formula (I), which is obtained by polymerizing the polyhydric phenol compound represented by formula (I) with a diamine compound, and the diamine compound is selected from the group consisting of a linear aliphatic diamine compound having 2 to 12 carbon atoms, a branched aliphatic diamine compound having 3 to 12 carbon atoms, an ether-based diamine compound having 3 to 12 carbon atoms, an aromatic diamine compound having 6 to 12 carbon atoms, and a polyamide-based polymer represented by formula (IIIc): 【Chemistry 2】 (wherein R 6 and R 7 each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms). or an aminocinnamic acid dimer represented by the formula: 【Transformation 3】 A polyamide polymer which is an aromatic diamine represented by the formula:

2. An adhesive comprising the polyamide polymer according to claim 1.

3. A molding material comprising the polyamide polymer according to claim 1.

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